CONTENTS

COVER PAGE

TITLE PAGE

FOREWORD | Stephen Fry

INTRODUCTION | John Mitchinson and John Lloyd

Aardvark

Albatross

Anglerfish

Ant

Armadillo

Badger

Bat

Bear

Beaver

Bee

Beetle

Binturong

Bison

Box Jellyfish

Butterfly

Cane Toad

Capercaillie

Cat

Catfish

Cheetah

Chimpanzee

Cicada

Comb Jelly

Coral

Cow

Crane

Dog

Dolphin

Donkey

Eagle

Echidna

Eel

Elephant

Ferret

Flea

Fly

Fossa

Fox

Frog

Giant Tortoise

Gibbon

Giraffe

Goat

Goose

Gorilla

Hedgehog

Hoatzin

Horse

Human

Hummingbird

Hyena

Kangaroo

Koala

Komodo Dragon

Leech

Lion

Lizard

Lobster

Louse

Mite

Mole

Monkey

Moose

Mouse

Naked Mole Rat

Octopus

Owl

Pangolin

Parrot

Pearl Oyster

Penguin

Pig

Pigeon

Platypus

Porcupine

Quoll

Rabbit

Raccoon

Rat

Salamander

Scorpion

Sea Cow

Sea Cucumber

Seal

Shark

Sheep

Snake

Spider

Starfish

Tapir

Tardigrade

Termite

Toad

Tuatara

Walrus

Wasp

Whale

Woodlouse

Woodpecker

Worm

TAILPIECE

ALSO BY JOHN MITCHINSON AND JOHN LLOYD

PREVIEW

COPYRIGHT

FOREWORD

|

Stephen Fry

Animals have this in common with one another: unlike humans they appear to spend every minute of every hour of every day of their lives being themselves. A tree frog (so far as we can ascertain) doesn’t wake up in the morning feeling guilty that it was a bad tree frog the night before, nor does it spend any time wishing it were a wallaby or a crane fly. It just gets on with the business of being a tree frog, a job it does supremely well. We humans, well . . . we are never content, always guilty, and rarely that good at being what nature asked us to be—Homo sapiens.

There is much to be learned from the animals. Much to be learned about them, of course, but much, much more to be learned about ourselves: our limits, our lonely uniqueness as a species, and, I would add, our greatness. The fact that we care with unreciprocated fervor about woodlice, woodpeckers, and wolverines is to our credit. I cannot subscribe to this modern idea that we should feel guilty about our role on earth, or inferior for having evolved a (self-)conscious mind. This is just Genesis wrapped up in new, even more sanctimonious clothes. The old religion and the new orthodoxy both claim we have guardianship over the earth and a “moral” responsibility for its destiny. Well, fine. But I will not apologize for committing the crime of being born any more than a marmot or a mosquito should. And between them, those two have been responsible for more death and upheaval than all human wars.

In the end, whatever weird and unfathomable purposes there might be to existence, to whichever theory of the development of life you might subscribe, we all have to face the fact that there is no entirely satisfactory explanation for the oddities and extremities of the zoological world.

INTRODUCTION

John Mitchinson

and John Lloyd

Animals know things we don’t. You may think this is pretty obvious, but in a book about “animal ignorance” it’s important to point out who it is that’s ignorant here. Spend a little time in the company of animals, even the ones stretched out on the bottom of your bed, and you’ll start to see the world differently. Look into their eyes and try to think what they’re thinking. It’s impossible, of course, which is what makes it so compelling. Whatever else we discover, however close we come to understanding the inner workings of the universe, we’ll never, ever know what it feels like to live life as a cat, much less an ant or a starfish.

Animals have fired our imaginations like nothing else—not God, not the weather, not other humans. From the moment we discovered we could daub shapes on cave walls, we’ve been painting, writing, and thinking about them. The magical rituals of hunter-gatherer peoples, their creation myths and healing practices, are all one long dialogue with the animal kingdom. To take on the power of an animal—the sight of an eagle, the speed of an antelope, the strength of a lion—these were the original superpowers. Most animals are still tirelessly exercising the same skills they’ve done for millennia. As a species, we’re very new kids on a very old block.

The original inspiration for this book was the medieval bestiaries. These were the most popular and influential books after the Bible itself. In them you’d be amazed to discover that weasels conceived through their ears, that bees were born from dead oxen, and that a goat’s blood was hot enough to dissolve diamonds. And scattered among the myths about real animals was “real” information about mythical beasts—centaurs, unicorns, dragons, manticores. Only rarely did bestiaries contain facts based on actual observation of nature. But nobody seemed to mind; the stories were too good to miss and anyway the real point was to teach human beings how to behave. What we liked was the idea of a collection of animals that didn’t leave you disappointed, as zoos so often do: a modern bestiary, based on zoological fact. After all, European eels swimming back and forth to Bermuda, octopuses’ arms that crawl for a month after they’ve been severed, mites so small they live inside a bee’s throat, or eight-legged water bears that can stay in a state of suspended animation for a century—these are even more outlandish than the wildest fantasies of the bestiary writers. They just happen to be true.

So here are a hundred animals, some supposedly familiar, some definitely obscure, all of them, without exception, quite interesting. We might easily have called it The Book of Animal Engineering. Ted Dewan trained as an engineer and, as his brilliant drawings show, how animals work is almost as mind-altering as how they behave. But this is not a workshop manual. Nor is it a reference book, or an animal rights polemic; it’s a menagerie, an armchair safari. It teaches only one unambiguous truth: that the word natural is meaningless. Animal strategies for feeding, reproducing, or just getting about are so madly various, so utterly, gloriously perverse that you end up believing that absolutely anything is possible.

And that’s the point. Animals cheer us up. They don’t need us to patronize them or to speak for them. But after studying them in such detail, it’s impossible not to feel they deserve our respect. The great American naturalist Henry Beston once wrote: “In a world older and more complete than ours, they move finished and complete, gifted with the extension of the senses we have lost or never attained, living by voices we shall never hear. They are not brethren, they are not underlings: they are other nations, caught with ourselves in the net of life and time.”

So come down to the waterhole of ignorance and wallow with us for a while.

Aardvark

Ancient, odd, and out on its own

Aardvarks are the last survivors of a primitive group of mammals that have lived in Africa since the dinosaurs. They were originally classified alongside anteaters and armadillos in the order Edentata (“no teeth”), but they are not remotely related, having evolved on different landmasses.

In fact, aardvarks don’t have any close relatives: they are the only mammal species that boasts an entire order to itself. Tubulidentata means “tube-toothed,” and aardvark teeth are completely different from those of any other animal. They are twenty flattopped pegs, made up of hexagonal tubes, right at the back of their mouths. Instead of enamel, they are covered with cementum, the stuff that is normally inside teeth. Like rodents’ teeth, they never stop growing.

The aardvark has a primitive, “designed by committee” look to it: the nose of an anteater, the ears of a donkey, the feet of a rabbit, and the tail of a giant rat. But don’t be fooled: it has out-lasted many other species because it does one thing supremely well. It is a termite-eating machine.

As soon as darkness falls it leaves its burrow and applies its snout to the ground, snuffling in huge zigzags across the savannah in search of mounds to crack open and lick clean. It can cover thirty miles and vacuum up more than ten pints of termites in a single evening. The aardvark nose contains more bones and scent receptors than that of any other mammal. Its ears can pick up the tiniest of underground movements and its powerful claws tear open mounds that would blunt a pickax. Aardvarks are strong: they can grow to the size of a defensive tackle and dig a burrow faster than six men using shovels. Their thick skin protects them from termite bites, and as the long, sticky tongue reels in supper, they can close their nostrils at will, to stop the insects running up inside.

Aardvarks are loners: it’s rare for them to meet up except to mate.

TERMITE TAKEAWAY

Once they’ve opened a termite mound, aardvarks will eat up to 500,000 termites in a sitting.

They have also built up a remarkably beneficial relationship with a plant known as the aardvark cucumber, which grows its fruits underground. Aardvarks dig them up and eat them when water is scarce, then bury their seed-laden droppings, ensuring the plants’ survival. The San (bushmen) of the Kalahari call the fruit “aardvark dung.”

Humans and hyenas are the only predators that will attack a fighting-fit aardvark. Despite its solitary, reclusive nature, a cornered aardvark is a formidable foe, slashing with its claws, kicking its legs, and executing high-speed forward somersaults.

“TO AARDVARK” IS AMERICAN COLLEGE SLANG FOR SEXUAL INTERCOURSE (I.E., ROOTLING AROUND IN DARK PLACES WITH A LONG THIN PART OF THE BODY).

Aardvarks are hunted for meat and leather: aardvark is Afrikaans for “earth pig” and they are said to taste like gamey pork. They are also called ant bears, but their Latin name, Orycteropus afer, means “African digger-foot.” The bushmen believe that aardvarks have supernatural powers because they are literally in touch with the underworld.

This elusive nocturnal animal probably only became known in the English-speaking world because it is so close to the start of the dictionary. It very nearly didn’t make it. Aardvark, the fourth noun listed in the 1928 Oxford English Dictionary, owes its inclusion to the editor James Murray, who overrode his assistant’s opinion that the word was too technical.

Albatross

Flying nonstop for a decade

There are twenty species of albatross from the gull-sized sooty to the vast wandering albatross (Diomedes exulans, or “albatross in exile”), with its record eleven-foot wingspan. They fly farther and for longer than any other family of birds. Satellite tracking reveals that some albatrosses fly around the entire planet in less than two months and can soar for six days without flapping their wings. Rather than soaring high up in the thermals like birds of prey, they keep close to the surface of the sea, using the lift generated by wind from waves. The most energetic part of any albatross flight is takeoff: it is the only time the bird needs to flap its wings vigorously.

As soon as a young wandering albatross gets airborne it won’t land again until it is ready to breed, which can be ten years later. Albatrosses feed on fish, squid, and krill, either diving into the sea or picking it off the surface, and sleep on the wing, with each half of the brain taking turns to shut down.

EVERYBODY COMMENDED THEM AND ATE HEARTILY OF THEM THO’ THERE WAS FRESH PORK UPON THE TABLE.

JOSEPH BANKS, ON BOARD THE ENDEAVOUR (1769)

Albatrosses belong to the order Procellariiformes, originally Tubinares, which means “tube-nosed.” These tubes run the length of their large, hooked beaks and lead to very well developed scent organs, allowing them to detect their food and nesting sites from many miles away. In some species the tubes have a dual function, allowing them to breathe from one part while sneezing excess sea salt from another.

Young albatrosses spend several years watching their elders to learn the elaborate beak-clacking courtship dances. When they find a partner, they mate for life, developing a unique body language, which they use to greet each other after long separations. They raise only one egg every two years, with the parents taking turns to sit on the nest or go off in search of food. An albatross will regularly fly one thousand miles for a single mouthful for its chick. Solid food is regurgitated, but for longer journeys it can also be broken down into a concentrated protein-rich oil, kept in their stomachs. This can be used in place of water to quench their thirst, or regurgitated as a nutritious fish smoothie for the chick.

The albatross’s most recognizable features are its huge wings. It costs very little muscle energy to keep them spread because of “shoulder lock”—a special tendon formation that keeps them in place.

Albatrosses can live for sixty years but breed so slowly that they are at risk of extinction within the next century. The main threat is long-line fishing. More than one hundred thousand die each year, caught in the millions of baited hooks that are used to catch tuna.

Samuel Taylor Coleridge’s poem The Rime of the Ancient Mariner (1798) practically invented the myth that killing an albatross brought bad luck. In fact, British sailors regularly killed and ate them, making pipes from their bones and purses from their feet. A more widespread belief was that the albatross was the reincarnated spirit of a drowned sailor. Some Scottish fishermen still don’t like using Swan Vesta matches because the bird on the box looks like an albatross.

When Portuguese explorers first saw them they called them alcatraz, their name for any large seabird. The word originally came from the Arabic al-gattās, the leather bucket on a water-wheel, which resembled a pelican’s bill. So, in Portuguese, the Birdman of Alcatraz literally means the “Birdman of the Large Seabird.”

Anglerfish

Worse things happen at sea

Surely a life doesn’t get any bleaker than that of the deep-sea anglerfish? Two miles down in the endless darkness, a gloomy motionless lump of brittle bone, atrophied muscle, and paper-thin black skin with only luminous bacteria for company. A life spent doing nothing except waiting, often for months at a time, turning your light on and off in the hope that it will attract some other creature out of the inky gloom long enough for them to stray too close to your cavernous mouth. . . .

The name “anglerfish” is used for about three hundred species—including sea toads, frogfish, batfish, and monkfish—that attract their prey with a long, flexible appendage like a fishing rod, typically growing out of the middle of their heads. At the end of it, in place of a dangling maggot, there is the esca (Latin for “food”), which can be wiggled to mimic live bait. On the deep-sea anglers, the esca lights up, thanks to a chemical process controlled by the bacteria that live on it. In return for light, the anglerfish supplies them with food. Different anglerfish have differently shaped escas. It was once thought this was to attract different prey, but it’s now believed that they all have a similar diet. Perhaps having a big, bendy, glowing rod sticking out of your head is a form of sexual display.

THE MALE PHOTOCORYNUS SPINICEPS IS THE SMALLEST KNOWN VERTEBRATE, A QUARTER OF AN INCH LONG, ABOUT A HALF MILLION TIMES LIGHTER THAN THE FEMALE.

The deep-sea anglers are some of the most ugly and outlandish creatures on the planet. They have an elastic stomach that can swallow prey twice as large as themselves (it even has a light-proof lining in case they swallow luminous fish). To prevent their prey escaping they have backward-facing teeth in their mouths and another set of teeth in their throats. The female illuminated netdevil (Linophryne arborifer) looks like a fluorescent root vegetable, with a black bulbous body and two shimmering lures streaming off like psychedelic foliage. Her Latin name means “tree-shaped toad that fishes with a net.” The hairy seadevil’s (Caulophryne polynema) huge spiny fins have a decayed look, its body is covered in unpleasant pale hairs, and its lure looks like a frayed stick of licorice. It has one of the most sensitive lateral lines of any fish—the tiniest movement triggers the opening and closing of its jaws. Elsman’s whipnose (Gigantactis elsmani) swims along upside down, trailing its lure along the seabed. The wolftrap seadevil (Lasiognathus saccostoma, or “hairy-jawed sack-mouth”) has a lure with three shining hooks on the end that it casts forward like a fly fisherman. Prince Axel’s wonderfish (Thaumatichthys axeli) has its lures hanging down from the roof of its mouth like a pair of fluorescent tonsils.

The male deep-sea anglerfish is much smaller than the female and doesn’t have a lure. He’s interested in mating, not fishing. He uses his giant eyes to look for a suitable female, and his enormous nostrils to sniff out her pheromones. Having found her, he latches on to her with his teeth and then starts to disappear. Scales, bones, blood vessels all merge into those of the female. After a few weeks all that’s left of the male are the testes hanging off the female’s side, supplying her with sperm. Females have been found with eight testes attached to their sides.

In some species, if the male fails to find a female, then he will eventually turn into one himself and grow massively in size. As the anglerfish themselves are wont to remark: there’s only one thing worse than being an anglerfish and that’s being a male anglerfish.

Ant

Chemical-dependent

Ants boggle the mind. In the jungles where three-quarters of them live, they teem 800 to the square yard, 2.4 billion to the square mile, and collectively weigh four times more than all the neighboring mammals, birds, reptiles, and amphibians put together. The 12,000 named ant species come in all shapes and sizes: a colony of the smallest could live happily inside the brain-case of the largest. As with bees and termites, their success flows from their social organization, but there is nothing remotely cuddly about ants: they are the storm troopers of the insect world, their ruthlessly efficient colonies operating like a single superorganism.

HARVESTER ANTS EAT MORE SMALL SEEDS THAN ALL THE MAMMALS AND BIRDS PUT TOGETHER. LIKE SQUIRRELS, THEY OFTEN FORGET WHERE THEY’VE PUT THEIR STASHES, SO RESPONSIBLE FOR PLANTING A THIRD OF ALL HERBACEOUS GROWTH.

Every process within an ant colony is regulated by chemicals. In some species, this can be refreshingly direct: the queen will climb to a high point when she is ready to mate, then stick her backside in the air and release a love pheromone that inflames the ardor of all males in range. Ant species mate in a variety of ways: in midair, on the ground, or in a mating ball, where the queen is completely surrounded by a swarm of love-addled males.

EARTHSCRAPER

Some ants’ nests can be more than ten feet deep, with each chamber devoted to a different function. Ants are born at the bottom, and slowly work their way to the top.

As well as love charms, pheromones also act as air-raid sirens. If the colony is threatened, many species emit a pheromone from a gland in their mouths. This causes some workers to grab the larvae and run underground while others prance around with their mandibles open, ready to bite and sting. Brunei ants even have guards that explode their own heads when threatened, leaving a sticky mess that slows down the intruders.

Interspecies warfare is common and ant raiders will take hostages back to their own colony, where they make them slaves. Other species use this to their advantage: the queen of Bothriomyrmex decapitans allows herself to be dragged to the nest of rival species, where, like a mini–Trojan horse, she bites off the head of the host queen and begins laying her own eggs. Being ants, the host workers switch loyalty without batting an antenna.

Some ants raise livestock. They collect the honeydew made by aphids and in return protect them from other predators. The ants “milk” the honeydew by gently stroking the aphid’s abdomen with their antennae. Meanwhile, more than two hundred species of ant are arable farmers, farming fungi for food. They gather compost for it to grow on, fertilize it with their dung, prune it, and even fumigate it with powerful bacteria to keep it parasite-free.

But for all their awe-inspiring industry and adaptive élan, ants don’t get it all their own way. The South American bullet ant (Paraponera clavata) is one of several species that finds out too late that fungi can sometimes farm them. Spores from a Cordyceps fungus work their way inside the ant’s body and release an override pheromone that scrambles its orderly world. Confused and reeling, the ant finds itself climbing to the top of a tall plant stalk and clamping itself there with its jaws. Once in place, the fungus’s fruiting body erupts as a spike from the insect’s brain and sprinkles a dust of spores on the ant’s unsuspecting sisters toiling below.

Armadillo

The best-endowed of all mammals

If the male nine-banded armadillo (Dasypus novemcinctus) were human, its penis would be four feet long. When you’re making love to something that resembles an upturned fishing dinghy, size matters.

Describing armadillos has always been a challenge: the Aztecs called them azotochtli, “turtle rabbits.”

All twenty species live in the Americas. The smallest is the pink fairy armadillo (Chlamyphorus truncatus), which is no longer than a sausage and looks like a furry prawn. The screaming hairy (Chaetophractus vellerosus) armadillo squeals like a pig when disturbed, though this seldom happens: it spends seventeen hours a day asleep and often won’t wake even if you pick it up or hit it with a broom.

The giant armadillo (Priodontes maximus) weighs up to 135 pounds (heavier than most Texan cheerleaders), sports lethal 9-inch claws, and has the largest number of teeth of any mammal: a hundred tubular pegs that never stop growing. The three-banded armadillo (Tolypeutes tricinctus) is the only one that can roll into a ball.

“Something for the weekend, sir?”

Nine-banded armadillos (despite the handicap of having wedding tackle big enough to scratch their own chin with) are strong swimmers. They swam the Rio Grande in 1850 and spread to most of the southern United States where there are now between thirty and fifty million of them.

THE POET DANTE GABRIEL ROSSETTI KEPT A PAIR OF ARMADILLOS AS PETS IN HIS BACK GARDEN IN CHELSEA. ONE OF THEM BURROWED ITS WAY INTO HIS NEIGHBOR’S KITCHEN–ITS HEAD APPEARED FROM UNDER A HEARTHSTONE AND CONVINCED THE COOK THAT SHE HAD BEEN VISITED BY THE DEVIL.

They have two ways of getting across rivers. Their bony armor means they naturally sink, so they can just stroll along the bottom, holding their breath for up to six minutes. If they need a longer swim, they gulp down air and inflate their stomachs into life jackets.

Males mark their territory with urine and their smell has been likened to that of an elderly blue cheese. To avoid giving birth in the winter, females can hang on to a fertilized egg for up to two years.

Other than humans and mice, nine-banded armadillos are the only animals seriously afflicted by leprosy: most armadillos in Louisiana are lepers.

In next-door Texas, armadillos are one of two state mammals—the other is the Texas longhorn. They’ve also been nicknamed the “Texan speed bump.” Their singularly ineffective defense mechanism is to leap several feet in the air when startled: Texan highways are littered with them.

As a result, armadillos lead the world in research into the function of the mammalian penis. The members of dead armadillos are regularly harvested from roadkill—a job made easier by the fact that they are so gigantic.

DURING THE GREAT DEPRESSION IN 1930S AMERICA, HUNGRY PEOPLE RESORTED TO BAKING ARMADILLOS. THEY WERE NICKNAMED “HOOVER HOGS” AS A DIG AT PRESIDENT HERBERT HOOVER.

Armadillos have been around for sixty million years: they are almost as old as the dinosaurs. In Bolivia and Peru, their shells are made into mandolins called charangos in imitation of Spanish guitars. They are then fitted with ten strings and generally tuned to A minor—a sad and noble key.

Badger

Woodland aristocrats

The parallels with the British upper classes are striking: badgers are stubborn creatures of habit; some of their setts, and the paths or runs that lead to them, are centuries old, handed down from generation to generation like stately homes. The largest sett ever found was a veritable Blenheim Palace with more than 130 entrances, fifty rooms, and half a mile of tunnels. Seventy tons of earth had been moved to make it. Most setts house a group of up to twenty adult badgers, known as a clan, and they will spend half their lives inside it, fast asleep.

Badgers are members of the Mustelid family, closely related to weasels and otters. “Mustelid” comes from the Latin for weasel, mustela, itself from the word for mouse, but badgers mostly feed on juicy earth-worms, and very rarely need to drink as a result. If pushed, they will eat mice, as well as rats, toads, wasps, beetles, hedgehogs, and even cereal crops.

BADGER HALL

Setts are very clean and organized, with bedrooms, private latrines, and communal rooms. They replace their bedding more regularly than most humans.

Their stripe lets other species know that they are strong, fierce, and ready to defend themselves. To communicate with their clan they produce a strong musk from glands under their tails. This is used for marking territory and establishing family identity. Each badger has its own unique scent and a clan odor made by the continual swapping of scent. Any adult that spends too long out of the sett risks rejection if his clan scent wears off. They have also evolved a vocabulary of sixteen different sounds, including churrs, growls, keckers, yelps, and wails. Hearing the wail was once taken as an omen of impending death.

Badgers can mate at any time of year, and sex can last for up to ninety minutes. The sow will mate with several different boars, holding all the fertilized eggs until she gives birth to a multifathered litter in the early spring. Only 60 percent of cubs will survive their first year of life. Most die by the time they are seven: one in six are killed on British roads each year.

Britain has the highest concentration of badgers of any country. Since 1985, the population has grown by 70 percent to more than 300,000, despite culling prompted by the belief that they spread tuberculosis to cattle. Paradoxically, culling badgers has the opposite effect. Since culling began in the 1970s, 59,000 badgers have been killed but more than 118,000 infected cattle have been slaughtered. This is because culling causes badger colonies to break up, forcing the infected survivors to move.

VICTORIAN GENTLEMEN USED THE BADGER’S PENIS BONES AS TIE PINS.

The European (or Eurasian) badger (Meles meles) spread into Europe from China two million years ago. They are still common there today. The hair for shaving brushes originates on the backs of Chinese badgers, which are culled as an agricultural pest. Despite the myth, they are not shorn like sheep.

The origin of the word badger is uncertain, but the best guess is the French bêcher, meaning “to dig.” The French call them blaireau, a word they also use for “shaving brush” and “tourist” (because of the well-worn tourist “badger runs”).

Badger meat was once eaten in both Ireland and Britain. Their hind legs were cured as “badger hams” and tasted like well-hung mutton.

Bat

Numerous, loud, well-groomed

There are a lot of bats. They account for a fifth of all mammal species and are more widely distributed, and come in a wider range of shapes and sizes, than any other mammalian order except rodents.

Their success isn’t hard to understand. They are the only mammal so far to sprout wings and fly, opening up a whole new world of habitats and food sources. Their order name, Chiroptera, means “hand wing,” and their wings remain recognizable as hands, with a thumb and four fingers. If our fingers grew to match them, they would be almost seven feet long and thinner than knitting needles.

Tendons and muscles are arranged to enable bats to hang upside-down when roosting. The bat spends no energy in hanging because its body weight automatically locks its clawed toes shut—even dead bats remain hanging.

The nine hundred species of bat are split into two families: the micros and the megas. The megas are the tropical fruit bats; the much more numerous micros are the echolocators. An average microbat emits four hundred thousand calls an evening. These chirps have been measured at 110 decibels: louder than the average rock band, but at a frequency too high for us to hear. Bats prevent damage to their own ears by closing them with every wing stroke. They also use the energy from the stroke to force the air through their larynx, so flaps, chirps, and ear muffling are perfectly coordinated.

Each chirp of sound can tell the bat the location, size, direction, and even the hardness of an object. It is accurate enough to detect a single thread of spider silk three feet away. Once locked on to prey the ultra-sound speeds up into attack mode.

The largest-ever gatherings of mammals are the fifty-million-strong roosts of the Mexican free-tailed bat (Tadarida brasiliensis mexicana) whose evening evacuation has to start in the midafternoon to allow them all time to exit.

TO THE CHINESE, BATS ARE LUCKY: THE WORD FU MEANS BOTH “BAT” AND “HAPPINESS.”

Inside the nursing roosts, there are more than fifteen hundred babies per square foot, yet the mother bats use sound and smell to feed only their own offspring. The females conceive while hibernating, warming up in their sleep as the wandering males caress them. The sperm stays alive inside the females until they wake in the spring and the eggs are finally fertilized.

Bats groom themselves for an hour a day, rubbing their wings with oil from glands on their faces, to keep them moist and supple. They can live for thirty years.

Vampire bats (Desmodus rotundus) feed mainly on cattle, horses, tapirs, and turkeys. If they do dine on humans, they usually go for the big toe, not the neck, but can only manage two tablespoons at one sitting. They are the only mammals to live exclusively on blood. It is a relatively low-energy food, so if a vampire bat fails to score over two consecutive nights it will die. To offset this, they have developed a sophisticated system in which adult females feed one another. They even remember who has helped them and make sure they get repaid first. A blood-thinning drug developed from vampire bat saliva, called draculin, is used to treat heart attack and stroke victims.

Bat guano is valuable as fertilizer and is a source of saltpeter used to make gunpowder. It is also nutritious: a quarter-pound of it contains more protein and minerals than a Big Mac.

Bear

Sleep, eat, sleep, sleep, eat

Male and female bears are known as boars and sows, despite being about as closely related to pigs as koalas are to bears, or pandas to cats. The bear family’s closest relatives are actually dogs, but one thing they do share with pigs is an omnivorous diet—most are as happy snacking on plants and fruit as they are gnawing on the leg of an elk. They can be fussy, too. Only a really hungry brown bear (Ursus arctos) eats a whole salmon. Most of the time it only goes for the high-nutrition bits: the brain, skin, and eggs. And even the exclusively carnivorous polar bear (Ursus maritimus) has an odd liking for toothpaste. They have been known to raid Arctic tourist camps, knocking over tents and trampling equipment just to suck dry a tube of Colgate.

POLAR BEARS AREN’T WHITE. THEIR SKIN IS BLACK, AND THEIR FUR IS TRANSLUCENT–THEIR APPARENT WHITENESS IS THE RESULT OF LIGHT REFRACTED FROM THE CLEAR STRANDS.

Bears spend much of their days eating, laying down fat reserves to get through the seven months they spend sleeping. Technically this isn’t hibernation but torpor, because their body temperature, respiration, and metabolic rate hardly alter. During this whole time they don’t eat, drink, urinate, or defecate but recycle their urea into protein and plug their anuses with a mixture of feces, hair, and bedding material called a tappen. Female bears even give birth in their sleep: the cubs are tiny and premature and weigh a tenth of those of similar-sized mammals. As a result bear’s milk is much richer than that of other carnivores and the cubs grow quickly. Newborn brown bears hum loudly while nursing, to help stimulate their mother’s milk production. Each cub in a litter is quite likely to have a different father. Unsurprisingly, female bears have little or no postcoital contact with their partners.

Bears can sleep for as long as a month in the same position if not disturbed. All other mammals, including humans, suffer from osteoporosis (a thinning and weakening of bone) if they maintain non-weight-bearing positions for a long time, but bears recycle calcium into their bones and wake up just as strong as when they nodded off.

If someone offers you a slice of polar bear’s liver, don’t be tempted. A pound contains enough vitamin A to kill you. A smaller dose will merely lead to headaches, blurred vision, loss of hair, drowsiness, diarrhea, and enlargement of the spleen and liver.

The government of the Yukon, as part of its official advice on what to do when you meet a bear, says that it “can be dangerous to crowd a bear’s personal space”—a statement that has about it the ring of truth. Brown bears can be black and black bears can be brown. Unfortunately, it’s important to know the difference: if confronted by a brown bear, you should play dead. If you do that to a carrion-loving black bear (Ursus americanus), it will start to eat you. Not that you are in any serious danger. In the United States, you are 25 times more likely to be killed by a snake, 180 times more likely to die from a bee sting, and 90,000 times more likely to be shot, stabbed, or beaten to death by a fellow human, than to die at the paws of a bear.

FRUIT AND NUT CASE

Despite being the top carnivore across much of the United States, black bears are 90 percent vegetarian.

Beaver

Engineer, submariner, pharmacist

Beavers have a greater impact on their surroundings than any creature other than humans. They build instinctively: put a young beaver in a cage and even without trees or running water, it still mimes the process of building a dam. They can chop down a tree with a six-inch diameter in less than an hour. Some scientists now think the disappearance of the Pennine forests and the creation of the Fens were due to the beavers that lived in Britain until the early thirteenth century (the town of Beverly in York-shire is named after them).

Beavers are rodents, like large squirrels. There are only two species: the Eurasian (Castor fiber) and the North American (Castor canadensis). Although similar in size and appearance the two have been separated for twenty-four thousand years, so can no longer interbreed. They are larger than you might think. A fully grown beaver is the size of an eight-year-old human. The giant beaver (Castor ohioensis), which became extinct ten thousand years ago, was the size of Mike Tyson.

Beavers can stay submerged for up to fifteen minutes. They have webbed hind feet, a flat tail to steer, transparent eyelids that work as goggles, fur-lined waterproof lips, and closable ear and nostril openings to enable them to gnaw underwater. The beaver’s four incisors are bright orange. The enamel contains iron, for extra strength, and they never stop growing.

Despite their busy reputation, beavers can be rather lazy. During winter the average beaver only leaves its lodge once every two weeks. In spring and autumn the beaver’s tail doubles in size. Beavers store their energy in their tails, so the tail shrinks as the fat is used up throughout winter.

Canadian trappers tamed and taught beavers to catch fish for them.

In 1760 the College of Physicians and Faculty of Divinity in Paris classified the beaver as a fish because of its scaly tail. This meant that French settlers in North America could officially eat beaver during Lent and on other fast days. Beaver tail is sup-posed to taste like roast beef.

Beavers were once seen as walking medicine cabinets. The secretion of two glands near their bladder was known as castoreum and, from the ancient Greeks onward, it was used as a fail-safe remedy for headaches, fevers, and epilepsy, and as a purgative. The Sami, in Lapland, mixed it with snuff. It is now only used in perfume. Shalimar by Guerlain and Magie Noire by Lancôme both contain synthetic beaver juice.

Unfortunately, the high value of castoreum and the fact that it sounds like “castrate” seem to have encouraged belief in the myth, propagated by Aesop and Pliny the Elder among others, that a hunted beaver gnaws off its own testicles to escape.

It doesn’t, but beavers were hunted nonetheless: in seventeenth-century Canada their pelts became a currency called a “made-beaver” or “M-B.” A gun was worth 132 M-Bs. At the same time in Britain, “beaver” came to mean “hat.” In 1628 Charles I declared “nothing but beaver stuff or beaver wool shall be used in the making of hats.” Beaver hats weren’t furry: their hair was ground, squeezed, and heated to make water-resistant felt.

CANADA IS BUILT ON DEAD BEAVERS.

MARGARET ATWOOD

Bee

Do I know you?

The most sophisticated form of communication other than human language is the work not of an ape but an insect. Honey-bees can tell one another the quality, distance, and precise location of a food source by a complex sequence of movements and vibrations called the waggle dance. And, unlike most of the dolphin or primate languages, we can actually understand what the bees are saying to each other (each waggle, for example, represents about 150 feet from the hive). The discovery of this in 1945 was enough to earn Karl von Frisch the only Nobel Prize ever awarded for the study of animal behavior.

More recent research has filled out the picture. Bees have a sense of time; being able to see in the ultraviolet range makes them more attracted to some flower colors and textures than others; they can learn by experience. They can even recognize human faces. Given that many humans struggle with this once they’ve turned forty, it seems utterly remarkable in creatures whose brain is the size of a pinhead. Yet bees who are rewarded with nectar when shown photographs of some faces, and not when shown others, quickly learn to tell the difference. Not that we should read too much into this. Bees don’t think in a meaningful way. There’s no small talk; they only ever communicate on two subjects: food and where they should set up the next hive. The faces in the experiment were clearly functioning as rather odd-looking flowers, not as people they wanted to get to know socially. Equally, a single bee, however smart, is severely limited in its appeal as a pet, when separated from its hive.

It’s not hard to see why bees were sacred to the Greeks, Egyptians, and Babylonians. Not only is the hive the epitome of a well-ordered society, it is also full of drama. A new queen, as soon as she’s murdered all her sisters, takes her nuptial flight, in which she mates in midair with up to fifteen drones. All the drones die (their penises explode with an audible pop, leaving the end inside her as a rather ineffective plug) and the queen returns with enough sperm on board to stock the entire colony on her own. A queen can lay up to fifteen hundred eggs each day during her three-year lifetime. She is constantly fed and groomed by attendant worker bees. Very occasionally the chemical balance wobbles and female workers start to lay as well, but rebellions are put down ruthlessly and all the impostors’ eggs are immediately eaten by fellow workers.

HONEYBEES DID NOT EVOLVE IN THE NEW WORLD: ENGLISH COLONISTS INTRODUCED THEM. NATIVE AMERICANS CALLED THEM “WHITE MAN’S FLIES.”

The species Apis mellifera also provides us with the only edible secretion, other than milk, that we can take from an animal without injury. Properly sealed and stored, honey is the one food that does not spoil. Archaeologists have tasted and deemed edible three-thousand-year-old honey found in the tombs of Egyptian pharaohs. Honey is hygroscopic, meaning it can absorb and hold moisture so that any molds and bacteria that touch it quickly lose their own moisture and die. But honey represents only a fiftieth of the true economic importance of bees. In the United States alone, bees pollinate crops worth $19 billion each year. Without them there would be no agriculture: every third mouthful of food we owe to the bee.

Beetle

The insect’s insect

If diversity and adaptability are the measuring stick for success, then beetles are the most successful animals on the planet. There are 350,000 known species, with up to 8 million more out there waiting for names: new species are being discovered at an aver-age rate of one an hour. If you lined up all animal and plant species in a row, every fifth species would be a beetle. There are about 750,000,000,000,000,000 individual beetles going about their business right now.

Why are there so many? The simple answer seems to be flowering plants. Not much happened for beetles until the flowering plants began to diversify 120 million years ago. They were the beetles’ food of choice and as they crept across the planet, adapting themselves to new environments, the beetles followed. In the process, they far outstripped even the plants; able to burrow, fly, and swim, beetles became the universal animal. If something’s edible, you can guarantee there will be a beetle out there to eat it. Ham, tobacco, ginger, bonemeal, paper, carpet, stuffed animals, strychnine, wood—all are grist to a particular beetle’s mandibles. The “short-circuit” beetle chews through lead sheathing on telegraph cables to get to the tasty fiber insulator around the copper wires. A specialist called Zonocopris gibbicolis feeds only on the droppings of large land snails, hitching a ride inside the shell.

Their mating strategies are just as varied. Flour beetles have even found a way of reproducing by proxy. When it’s not chewing its way through the nation’s stores of grains and cereals, you’ll usually find Tribolium castaneum copulating. They are very promiscuous, even by insect standards. The male starts by using his spiny penis to sweep out a previous occupant’s load, before unleashing his own. Unfortunately, his rival’s sperm has a way of clinging to his tackle, so his next conquest stands a one in eight chance of finding herself fertilized by a beetle she’s never met.

A BLISTER BEETLE HONEYTRAP

Larvae of the blister beetle form themselves into the shape of a female digger bee. Attracted by the pheromones, a male bee attempts to mate.

Frustrated, the male bee flies off with larvae attached to chest hair.

These larvae transfer to females when he finally gets lucky, and then on to the nest to feed on honey and young bees.

We have much to learn from the beetle. But far from being just a grotesques’ gallery, they are a living laboratory, where almost every extreme has been tested, every obstacle overcome. The bombardier beetles, who fire a boiling chemical spray out of their rears at three hundred pulses per second, might help us to reignite jet engines that cut out during a flight. Tenebrinoid beetles from the rainless Namib desert, who can channel the morning dew into their mouths using the microscopic bumps and troughs on their backs, are being used to develop new fog harvesting technology; and the jewel beetle (Melanophila acuminate) may hold the clue to an early-warning system for forest fires. It has an infrared sensor under one of its legs that can detect a fire more than fifty miles away. Why? So that it can fly toward the blaze. It knows the smoldering tree trunks offer a rare predator-free opportunity to mate recklessly and lay its eggs.

BEETLES ARE NOT ARISTOCRATIC, VAIN ESOTERICS, LIKE BUTTERFLIES AND MOTHS, OR COMMUNISTS, LIKE ANTS AND BEES. THEY’RE NOT FILTHY, OPPORTUNISTIC CARPETBAGGERS LIKE FLIES. THEY ARE PROFESSIONAL, WITH A SKILL. THERE IS NOWHERE THAT DOESN’T, SOONER OR LATER, CALL IN A BEETLE TO SET UP SHOP AND GET THINGS DONE.

A. A. GILL

Only a beetle. . . .

Binturong

Smell my popcorn

High in the trees of southern Asia’s tropical forests there lives the only Old World carnivore that uses its tail for climbing. Commonly called a bearcat, it is neither a bear nor a cat but a member of the civet family. Civets are related to cats but are also cousins to the mongoose and the hyena. The bearcat, or binturong (Arctitis binturong), gets its name from a Malaysian language that no longer exists, and at first glance it’s not hard to understand the confusion: it has the face and whiskers of a seal, the thick shaggy fur and flat feet of a bear, the tail of a monkey, and the claws of a mongoose. And it’s no tiny, scampering marmoset: it weighs forty-two pounds and is six feet long (imagine a golden retriever that can use its tail to climb trees). So, although binturongs spend almost all of their lives in the canopy, they tend to move around quite slowly, which sometimes leads people to mistake them for sloths.

The binturong tail is a three-foot-long, muscular fifth arm with a bare leathery patch at the end for gripping, just like a monkey’s, although they evolved quite separately. Also, just like monkeys, they use their tail to pick and hold food as well as for hanging from branches. The tail is powerful enough for them to walk down a tree trunk headfirst or upside down along a branch to pick hard-to-reach fruit.

Binturongs live mostly on fruit and have a very sweet tooth; in captivity, they show a strong preference for ripe bananas and mangoes but have been known to wolf down marshmallows, muffins, apple pies, and milk shakes. This tends to bring on a sugar high, leading to an hour of uncharacteristically manic leaping and running around before they collapse, exhausted, and sleep it off. Despite this, wild binturongs are genuine carnivores and will occasionally snag a bird or catch a fish (they are excellent swimmers).

Like the other civets, the binturong marks its territory with a pungent oil. Civet oil was used for centuries as a valuable additive to perfume, collected from the glands of civets and genets with a special spoon. The binturong has a large gland under its tail, and wipes it on branches, posts, and other landmarks to leave a calling card that lists precise details about sex, age, and sexual status. Compared with some other civet species, the binturong’s scent smells pleasantly of buttered popcorn. It’s left by both males and females, although the female binturong wears the trousers: she is much bigger and—although it isn’t quite in the hyena league—has a large, penislike clitoris. Both sexes have been hunted for their oil, and the male’s penis bone is a valuable ingredient in traditional Chinese medicine, promoting virility and the conception of male children.

DON’T TRY THIS IF YOU ARE A BEAR

SEVERAL U.S. COLLEGES HAVE SPORTS TEAMS CALLED “BEARCATS” AND REFER TO “A MYTHICAL ANIMAL THAT COMBINES THE POWER AND FEROCITY OF A BEAR WITH THE CUNNING AND QUICKNESS OF A CAT.” THEY OBVIOUSLY HAVEN’T MET THE AMIABLE BINTURONG.

Unlikely as it sounds, the other reason binturongs are taken from the wild is that they make excellent pets, although presumably not indoor ones, because of their need to climb. They have become popular in the United States, where a fertile adult can fetch up to $2,000. Apparently, they are easy to tame and the tail even acts as a built-in leash—they will grip your hand with it when you take them out for a walk.

Bison

Seventy million killed in fifty years

The bison herds of North America’s Great Plains formed the greatest mass of land animals in the history of the planet. They could stretch fifty miles long by twenty miles wide. By 1890, there were only 635 bison left.

The American plains bison (Bison bison) is commonly called the buffalo, although it is not related to true buffaloes. It migrated from Asia into America four hundred thousand years ago and is now the biggest North American mammal: adult males weigh a ton, are ten feet long, and stand six feet tall at the humped shoulder.

Bison are the most efficient machines yet developed for eating grass. Their teeth are wide (to maximize the volume of each bite) and long (to stop them wearing out quickly). Forty percent of their body weight is digestive tract: their fourth stomach chamber holds six hundred pints but a mouthful of grass takes up to ninety hours to digest. Bison chew the cud like cows, but extract a third more nutrients.

Since the end of the last ice age, the bison’s only predators have been bears, wolves, and humans. Many archaeologists now believe that it was hunting by early humans that made them form large herds.

The bison’s hump acts as an energy-saving cantilever to its large head, making sure the mouth is always close to the ground, ready to eat.

The head doubles as snow shovel.

The size of the herds means an amorous male has to stand out. Successful males have evolved bigger heads and more powerful front legs and shoulders, covered in darker woolly hair. Rutting males run full tilt at one another and clash heads: the sound carries for three-quarters of a mile.

Without bison urine there would have been no prairie: it transformed the fertility of the soil. The more bison, the more grass, the more bison. The fragrant bison grass, used to flavor vodka, thrives on bison urine.

It was the railroad that started the slaughter. The work-men who built railways across the United States in the mid– nineteenth century needed meat for food. At the same time, the British army decided “buffalo” leather made the best boots. Hunters were offered $2 a hide (called robes) or 25 cents for a tongue. A full-time bison hunter like Wyatt Earp or Buffalo Bill Cody could kill a hundred in an hour. Shooting bison for fun from moving trains became a popular pastime.

IN MEDIEVAL BESTIARIES, THE EUROPEAN BISON WAS KNOWN AS THE BONNACON, OR “VILDE KOW,” WHICH DEFENDED ITSELF BY SPRAYING A JET OF EXCREMENT OVER A DISTANCE OF EIGHTY YARDS.

It was all over by 1890. Only one in five of the slaughtered bison were put to commercial use; the rest rotted on the ground. The total contribution of the fifty-year buffalo trade to the

U.S. economy was $20 million, a paltry 28 cents per animal. Specicide led to genocide.

The indigenous tribes relied on bison for every aspect of their livelihood. The U.S. government encouraged the systematic extermination of the herd as the simplest way of ethnically cleansing the valuable prairie lands.

Today, the North American herd has recovered to 350,000. Most are photographed by tourists or farmed for food. With a third more protein and 90 percent less fat, bison meat is more nutritious than beef. Cattle and bison hybrids are also bred for eating: they are called “cattalo” and “beefalo.”

Box Jellyfish

The stomach with twenty-four eyes

Despite appearing to be just a mouth surrounded by tentacles, box jellyfish or cubozoans (literally “cubed animals”) have eyes with lenses, corneas, and retinas very similar to our own. Odder still, despite having all this sophisticated equipment, their eyes are permanently out of focus.

This is because a box jelly doesn’t have a brain, just a ring of nerves around its mouth. Without central processing power, the blurry vision tells it all it needs to know. How big? Can I eat it? Will it eat me?

The eyes are on four clublike stems on each side of the cube-shaped body. As well as two “smart” eyes, these stems each have four light-sensitive pits. Again, this is linked to their lack of a brain, which could integrate sensory information. For box jellies, “seeing” a predator and knowing whether it’s day or night are separate tasks that require separate sense organs.

Their eyes differentiate them from the rest of the true jellyfish clan (the scyphozoans, from the Greek skyphos, “cup”) from which they split at a very early stage, more than 550 million years ago.

Sight, however blurred, helps them in other ways. Unlike true jellyfish, which limply float waiting for food to swim toward them, box jellies can swim at speed (six feet per second in some species) and steer around obstacles.

This means they are able to “hunt” prey. There is also evidence that they form mating pairs, with the male using his tentacles to impregnate the female, rather than just spraying eggs and sperm into the sea.

This also helps to explain their other major adaptation. Box jellies are fantastically dangerous. One species, the sea wasp (Chironex fleckeri), is probably the most venomous creature on earth. Its sting produces instant, excruciating pain accompanied by an intense burning sensation. The venom attacks the nervous system, heart, and skin, and death can occur within three minutes. Up to ten thousand people worldwide are stung each year, and there are regular fatalities.

Another species, Carukia barnesi, is almost as toxic. Virtually invisible in water, being transparent and no bigger than a peanut, it is completely covered in stinging cells. Those who survive its sting may suffer Irukandji syndrome, experiencing intense pain, nausea, vomiting, catastrophically high blood pressure, and a feeling of impending doom. It is named after an Aboriginal tribe whose folklore tells of a terrible illness that struck people who went swimming in the sea. The venom causes a massive release of the fight-or-flight hormone noradrenalin, so victims often panic to death.

BOX JELLIES GO TO BED AT 3:00 P.M. AND GET UP AT DAWN. ONCE DARKNESS BEGINS TO FALL THEY LIE MOTIONLESS ON THE OCEAN FLOOR, APPARENTLY “SLEEPING.”

Why are box jellyfish so toxic and how is this linked to sight? it’s a question of scale. Because they can see, they tend to eat things larger than themselves. In order to minimize damage to their own rather delicate tentacles, they need to paralyze their prey immediately. They are only fatal to us because we are so large we blunder into them, exposing ourselves to far more of their sting cells than they usually need to kill their prey.

Butterfly

Souped-up moth

Butterflies and moths are the most numerous insect family after beetles, with two hundred thousand known species. Although butterflies are the more popular, carrying with them associations of sunshine and summer idleness, it’s the moths who make up 80 percent of the Lepidoptera (“scale-wings”). One of the reasons for this is temperature: butterflies are basically high-performance sex machines fueled by flower nectar, Formula One cars to the moth’s family saloon. If a butterfly’s body temperature falls below 86°F it can’t fly and will either die or fall into a torpor. That’s why northern countries like Britain are relatively poor in butterfly species—there are only fifty-nine natives and some of them, like the red admiral and the painted lady, migrate annually, all the way from the Mediterranean. In comparison, continental Europe has more than 400 species of butterfly, and tropical Costa Rica (which is the size of Wales) has 560.

Moths are much hardier and are usually nocturnal. Their bodies are designed to conserve heat rather than absorb it, so they tend to have fatter, fur-covered bodies and rest with their wings spread to the side, rather than folded together above their backs like butterflies. Another point of difference is the antennae: butterflies have a smooth antenna rod with knobs at the end; moths’ are feathery. Again, this is partly to do with the day/night split. Moths are much less dependent on sight: they use their antennae as spatial orientation sensors, like our inner ears, to steady themselves as they fly and hover. Cut a moth’s antennae off and it will immediately collide with walls and crash to the ground.

SILKEN SECRET

For three thousand years only the Chinese knew how to extract silk from the Bombyx mori moth.

Each cocoon produces a single 3,000-foot thread of silk.

Ten unraveled cocoons would reach the summit of Mount Everest.

A kimono uses 2,000 cocoons.

Sight is important to butterflies but not quite in the way we imagine. Despite their beautiful appearance, butterflies are extremely nearsighted and cannot judge distance. This is an evolutionary trade-off: their vision may not be sharp, but they can see almost the full 360 degrees, both vertically and horizontally, which is handy for evading predators. The bold wing patterns have more to do with scaring off hungry birds than attracting mates. What really gets a female butterfly going is the male’s iridescent wing scales. These, arranged into the characteristic eye-spot patterns, are ridged to reflect UV light—as he flutters his wings at close range he creates a UV strobe effect. Accompanied by heady gusts of pheromone, this literally mesmerizes the female.

UNLIKE MOST ANIMALS, NONE OF THE WORDS FOR “BUTTERFLY” IN EUROPEAN LANGUAGES RESEMBLE ONE ANOTHER: IT IS SCHMETTERLING IN GERMAN; PAPILLON IN FRENCH; MARIPOSA IN SPANISH; FARFALLA IN ITALIAN; BORBOLETA IN PORTUGUESE; AND VLINDER IN DUTCH.

Moths, for obvious reasons, tend to rely more on smell and hearing: a moth can sniff a potential mate seven miles away. Moths’ ears are simple but effective; some species of tiger moth can even tune them to pick up the ultrasonic hunting call of bats and use their wing beats to create a jamming frequency. Both groups have scent scales, which release pheromones to attract females and help their own species recognize them. The common blue butterfly smells strongly of chocolate; the goat moth smells of goats.

Many species of moth feed on the tears of larger animals. Tears are a surprisingly nutritious broth of water, salt, and protein—like our sweat, which butterflies like to lick. Some, like Mabra elantophila, are tiny and hardly trouble the elephants they steal from; others, like Hemiceratoides hieroglyphica from Madagascar, are large and sneaky: they have harpoon-shaped proboscises covered with hooks and barbs that they insert under a bird’s eyelids as it sleeps.

Cane Toad

Alien invasion

On August 18, 1935, 102 cane toads arrived in Australia from Hawaii. The toads were released onto the sugar cane plantations of northern Queensland to control the ravages of the cane beetle.

Seventy years later, there are now a hundred million cane toads in Australia. They have spread into an area bigger than Britain, France, and Spain put together, and the front line of their territory expands at a rate of thirty-five miles per year.

Given the catastrophic decline of the world’s amphibious species (see Frog), this may sound like good news. But cane toads aren’t good news. They are a catastrophic example of what can happen when humans try to manipulate nature.

Bufo marinus is very poisonous. Swallowing them as eggs, tadpoles, or adults leads to near instant heart failure for most animals. Australian museums display snakes that died so quickly the toad is still in their mouths. Native cats, or quolls, used to eating home-grown frogs, are threatened with extinction. Cane toads can even take out large crocodiles. Their poison is so strong that pet dogs become ill just by drinking water from bowls cane toads have walked through.

CANE TOADS MAY YET PROVE USEFUL: THEIR TADPOLES INHIBIT THE GROWTH OF MOSQUITO LARVAE AND THE VENOM CONTAINS SEROTONIN, WHICH CAN BE USED TO TREAT HEART DISEASE, CANCER, MENTAL ILLNESS, AND ALLERGIES.

In their home territories of Central and South America, cane toad populations are held in check by a combination of competition, disease, and predators. In Australia there aren’t any other toads; there are few predators and lots of new things to eat. It’s virgin territory, and they have risen to the challenge.

They produce four times as many eggs as native Australian frog species, and their tadpoles not only mature more rapidly but—being poisonous—don’t get eaten. Juveniles and adults will consume anything, from other frogs to unguarded bowls of dog food. The more they eat the bigger they get: some have been recorded at six pounds—the size of a small dog.

Even more worrisome, their new home seems to be changing them. Their legs are now 25 percent longer than they were in the 1930s and they can travel five times faster, waiting until the evening to use man-made roads and highways rather than scrabbling through the bush.

Cane toads are expected to move into southern Australia within the next ten years.

Action to control the spread of the toads is widespread, particularly along the border of Western Australia, where the invasion is expected in early 2008. Anti-toad measures once involved driving around so as to run them over in cars. Although cruel hands-on methods like “cane toad golf” still have their advocates, the most effective control is through nocturnal “toadbuster” squads, which raid the waterholes where they gather. A good week’s haul might top forty thousand toads. They are then either gassed or deep-frozen to death and turned into liquid fertilizer called ToadJus.

A biological solution to the plague—genetically engineering a disease to render them sterile—is opposed by many environmental scientists, not least because it was that kind of thinking that caused the problem in the first place.

Despite its undeniable environmental impact, the cane toad has not yet caused any extinctions. Some birds and rodents have even learned to flip them over and eat them by avoiding the poison glands. Many other species have grown to tolerate them, not least the sugar cane beetle, whose Australian population is, if anything, higher than it was in 1935.

Capercaillie

The fatuous grouse

Capercaillies, also spelled “capercailzies,” are huge woodgrouse as big as turkeys. The name is Gaelic for “forest horse”—although there are no capercaillies (just as there are no snakes or moles) in Ireland. The Royal Society for the Protection of Birds gives the collective noun for capercaillies as a tok. Interestingly, however, tok is not a word in Gaelic, Danish, Norwegian, or Finnish—the local languages of some of the places where these birds are found—nor, according to the Oxford English Dictionary, is it a word in English either. (Tok is, however, the spelling of “talk” in pidgin English and a first name in Chinese. It’s also a town in Alaska: pronounced “toke,” it means “peaceful crossing” in Athabascan Indian. But we digress.)

The call of the male capercaillie imitates the sound of dripping water in early spring. It starts off with a similar pelip-pelip sound and then picks up speed with plip-plip-plip-itit-t-t, ending with -klop!, which sounds like a cork being pulled out of a bottle. The much smaller and less flamboyant females content themselves with a pheasantlike clucking noise. Male capercaillies perform a bizarre courtship ritual called a lek (from an Old Norse word meaning “to dance”) and they do this at so-called lekking sites. This involves strutting about with tails fanned out and wings held down, making an extraordinary series of noises, including strangled gurgling, asthmatic wheezing, and, of course, cork-popping. Some experts believe that there are also other sounds, below the range of human hearing, which carry for many miles, broadcasting the male’s splendor to distant females. When the eager females arrive, crouching and making enticing begging noises, spectacular fights break out among the males, resulting in injury or even death. Those males whose grandiose exertions fail to find them a partner can become extremely frustrated and will perform their absurd antics to anything that moves, even cars.

DESPITE A VALIANT REARGUARD ACTION BY THE RSPB, THE CAPERCAILLIE HEADS THE LIST OF BRITISH BIRDS LIKELY TO GO EXTINCT BY 2015. IF IT DOES, IT WILL BE THE ONLY BRITISH BIRD TO HAVE MANAGED THE FEAT TWICE.

Capercaillies became extinct in Britain around 1785, owing to overhunting and forest clearances. In the 1830s a few birds were imported from Sweden, and by 1960 there were twenty thousand of them in Scotland. Today there are only about a thousand: the population has halved in the last five years and the bird is in danger of becoming extinct again. About a third of the deaths are due to the ponderous, low-flying creatures colliding with deer fences—and a few of them, no doubt, from giving the come-on to moving hatchbacks.

The longest recorded life span of a capercaillie is 9.3 years. A 1992 study of deviant capercaillies in Finland found that about one percent of males behaved abnormally due to testosterone levels up to five times higher than the average. This may be because capercaillies live almost exclusively on a diet of blueberries, a fruit that is supposed to increase the libido and cure erectile dysfunction in humans. Addled by blueberry-fueled lust, Finnish capercaillies displayed to humans, attacked stuffed male capercaillies, and copulated with stuffed females. In 1950 there were three times as many capercaillies in Finland as there are today. This may be because so many of them are stuffed for scientific purposes.

LEK LOUTS ON THE LASH

As well as all the gurgling, burping, and cork-popping, lek fights between two males can be incredibly vicious, leading to severe injury and even death.

The winner gets to mate with ALL the females; the frustrated loser withdraws and goes off to beat up other birds, cars, or natural-history film crews.

Cat

Cuddly killer

What is a cat? Every child knows. Yet cats, among the most familiar of animals, are ineffably mysterious. What are they for? What do they want? Cats spend 85 percent of their day doing absolutely nothing. Eating, drinking, killing, crapping, and mating take up just 5 percent of their life. The other 10 percent is used to get around. Otherwise they are asleep, or just sitting. They say cats were the last animals to be domesticated, by the ancient Egyptians around 3,500 years ago. But it is cats that have domesticated us, in their own time, for their own reasons. Today, only a quarter of American cat “owners” say they deliberately went out to acquire a cat; in 75 percent of cases, it was the cat that acquired them. And studies have shown that many more people claim to own a cat than there are cats. When your cat disappears for a while it is not, in fact, off on a hunting expedition; it is two doors down having another free meal or asleep on the windowsill with one or another of its many doting “owners.” Cats need to eat the equivalent of five mice a day. A cat given unlimited access to food will only eat a mouse-sized portion at a single meal. Is your cat eating five meals a day? Of course not: it’s dining out elsewhere, later.

One of the big selling points of cats is that they are clean animals that carefully cover up their own feces. Except they don’t always—they only do it about half the time. They leave piles of the stuff all around the edges of their territory as a kind of malodorous “Keep Out” sign. The polite word for this is scats. Milk, cat food, and central heating are all bad for cats. Milk gives them diarrhea, cat food rots their gums, and central heating causes them to molt year-round. Then they lick off and swallow their fur, which clogs up their digestive system.

MOST CATS CARRY A PARASITE THOUGHT TO HAVE LONG-TERM, IRREVERSIBLE EFFECTS ON THE HUMAN BRAIN. TOXOPLASMA GONDII MAY TURN MEN INTO GRUMPY, BADLY DRESSED LONERS AND WOMEN INTO PROMISCUOUS, FUN-LOVING SEX KITTENS. A QUARTER OF THE U.S. POPULATION ARE ALREADY INFECTED. . . .

There are about 75 million cats in the United States, which are responsible for the deaths of a billion birds and five billion rodents every year. Right up until the seventeenth century it amused people to stuff wicker effigies of the pope with live cats and then burn the lot. This produced sound effects that pleased Puritans but not cats: they have exceptionally sensitive hearing and can even hear bats.

Research has proved what every cat owner knows: apart from human beings, cats have a wider range of personalities than any other creature on the planet. And yes, they are intelligent. Very. When they can be bothered. There are numerous well-documented stories of cats abandoned by their owners tracing them to locations hundreds of miles from home. Can cats read maps? Maybe. They can certainly tell the time, as recent experiments have shown. The ancient Egyptians worshipped cats as gods: killing a cat, whether deliberately or not, was a capital offense. When a cat died, its owner was expected to shave off his eyebrows. Whose idea was that? A cat’s, of course. Cats don’t have eyebrows.

Catfish

Swimming tongue

There are more than twenty-two hundred species of catfish, and they are found on every continent except Antarctica. They live in the frozen rivers of Siberia and the steamy swamps of Borneo. Species have been found in the Himalayas and the Andes at altitudes above fourteen thousand feet, while others bask in the warm coral reefs of the South Pacific. They range in size from some of the smallest known fishes to the largest. Scoloplax dicra is fully grown at half an inch while the European wels (Silurus glanis) grows to 16 feet and can weigh 650 pounds.

FOOD HISTORIAN AND DIPLOMAT ALAN DAVIDSON ONCE CANCELED AN OFFICIAL RECEPTION SO HE COULD TRAVEL NORTH TO TASTE AND RECORD A RARE CATCH OF THE WORLD’S LARGEST FRESHWATER FISH, THE PA BEUK OR GIANT MEKONG CATFISH. HE CONSIDERED ITS FLAVOR “UNMATCHED . . . COMPARABLE TO VEAL.”

Catfish account for about 8 percent of all fish and are among the most remarkable creatures on earth. There is a talking catfish, a walking catfish, an electric catfish, an upside-down catfish, and a catfish that looks like a banjo, but what really makes them stand out is their senses—the most finely tuned in nature. They have more taste buds than any other creature. Their entire bodies are covered with them. A six-inch catfish may have more than a quarter of a million taste buds, not just in its mouth and gills, but also on its whiskers, fins, back, belly, sides, and tail. The channel catfish has the best sense of taste of any vertebrate, able to detect less than a hundredth of a teaspoonful of a substance in an Olympic-sized swimming pool full of water.

THE MOUTHBROOD DIET

The male hardhead catfish hatches the fertilized eggs in his mouth.

Catfish also have extraordinary senses of smell, touch, and hearing. They can smell some compounds at a dilution of one part in ten billion. They have no visible external ears, but because they are the same density as water, their whole body acts as a giant ear. In addition, ultra-low-frequency sound is picked up by the lateral line, small pores along the fish’s side containing tiny hairlike projections that are supersensitive to vibrations. These are used to find prey and avoid predators. The Chinese have exploited this talent for centuries, using catfish to warn of earthquakes: they are said to be able to detect them days in advance.

Catfish do not have scales—their smooth skin gives them a heightened sense of touch—and some also have excellent eye-sight, especially the channel catfish (Ictalurus punctatus, Latin for “spotted fish-cat”), whose eyes are used for medical research into vision. Other parts are used to study herpes, their gonads are removed for research into reproduction, and, if that were not enough, this unfortunate creature (variously known as the willow cat, forked-tail cat, spotted cat, or lady cat) is also delicious. It ranks third after bass and crappie as the most popular fish to catch in Texas. As well as all the familiar senses, catfish—like sharks—have an extra one called electroreception that detects the electrical fields of worms and larvae buried in mud. Most catfish are harmless to humans (though some can give you a nasty jab with their toxic spines) but beware the candiru, a tiny catfish that lives in the Amazon. If you swim in its murky waters and urinate, the fish will find its way into your urethra. Once inside, it erects its spines, causing inflammation, hemorrhage, and death.

Cheetah

The savannah strangler

Cheetahs used to range across the whole of Africa and most of southern Asia. Over the past century, their population has shrunk dramatically as a result of hunting for fur and to protect live-stock. Of the twelve thousand surviving animals, only a hundred survive in Asia, in a tiny wildlife park in the Iranian mountains.

CHEETAHS CAN PURR, CHIRP, AND YELP, BUT THEY CAN’T ROAR.

Cheetahs have almost disappeared before. The modern population can be traced back to a single African group of five hundred animals that survived the last ice age. Genetically, this means all living cheetahs are as close as identical twins.

Cheetahs are fast because they have to be: unlike most big cats, they hunt during the day, climbing termite mounds to spot stray antelope or gazelle. The black “tears” under their eyes are thought to cut down glare, and they have a wide, supersensitive stripe on their retinas that gives sharp focus across the entire width of their vision, allowing them to chase and turn with near perfect accuracy. Anything within a two-mile radius is in trouble.

Only a handful of cars can reach 60 mph faster than a cheetah and none can do it on grass. But they have to be quick. Unless the antelope is caught within thirty seconds, the cheetah will overheat. They kill by strangulation. Their teeth aren’t as long or as sharp as a lion’s or a leopard’s but their bite is more powerful, crushing the windpipe and blocking the airflow. If successful, it then has to bolt its food, leaving behind the skin, bones, and intestines. An adult can take on board up to thirty pounds of flesh in a sitting (equivalent to an adult human polishing off six legs of lamb) and survive on it for five days. Lions, vultures, and hyenas steal half of all kills, but cheetahs don’t argue. They know a single injury to their “fit-for-purpose” body will doom them to starvation.

ANCIENT EGYPTIAN TOMBS SHOW PAINTINGS OF THE CHEETAH, WHICH WAS REVERED AS A GOD. CHEETAH HEADS ARE EVEN CARVED INTO TUTANKHAMUN’S FUNERARY BED.

BUILT TO SPRINT

A female cheetah will sometimes bring back a live antelope calf to train her offspring. Cubs start hunting at eighteen months and, untrained, will often chase after completely inappropriate prey, like buffalo.

Cheetah is originally a Hindi word, chita, which comes from the Sanskrit chitraka, meaning “speckled.” There was confusion for a long time between cheetahs and leopards. When a medieval writer uses “leopard” he usually means a cheetah. They were believed to be the illegitimate offspring of lions (which have manes) and “pards” (which were spotted). Cheetah cubs do have manes (it helps camouflage them in grass). Their Latin name, Acinonyx jubatus, means “fixed-claw with a mane.”

In ancient Egypt, India, and Persia, cheetahs were trained to hunt by humans. Rewarded with butter and taught to recognize fifteen vocal commands, they were taken out on horseback, wearing hoods like falcons, and then set after antelope.

They are notoriously difficult to breed in captivity because the female needs to be chased by several males before she can ovulate. The sixteenth-century Mughal emperor, Akbar the Great, kept more than a thousand cheetahs but managed only one litter. The next cheetah born in captivity wasn’t until 1956.

Chimpanzee

The thinking man’s ape

It is almost impossible to discuss the history of our nearest living animal relative without talking about ourselves. In 2002 a series of British TV ads featuring chimpanzees dressed as a family of humans ended after forty-six years—the longest-running advertising campaign of all time. Their undeniable charm was based on a fallacy: that chimpanzees are like cheerful, uncoordinated human children. The irony is that the opposite is probably closer to the truth: that humans are chimps who didn’t grow up. We got smart instead.

Adult chimps (Pan troglodytes) may not be much taller than a ten-year-old, but they weigh twice as much and have five times the upper body strength of an adult human. Chimps can recognize themselves in a mirror, vocalize, and use sophisticated gestures to communicate. Young chimps laugh when playful or being tickled. They appear to express emotions. They don’t have the physiology for speech, but they can learn some human sign language—though without grammar or syntax. They can use a variety of tools—some fish for termites with twigs; others crack nuts with rocks or sharpen spears with their teeth. They learn from one another. To this extent, different groups of chimps have their own cultures.

“CHIMPANZEE” IS FROM THE BANTU KIVILICHIMPENZE, MEANING “MOCKMAN.” IT WAS FIRST USED BY EUROPEANS IN 1738, ALTHOUGH SIXTEENTH-CENTURY PORTUGUESE EXPLORERS CALLED THEM “PYGMIES.”

In particular, their sister species the bonobos (Pan paniscus), only identified in 1929, seem to approach the common problems of food distribution and reproduction from a much jauntier angle. Whereas chimp groups are run by a team of dominant males, bonobos are like a feminist hippy collective, with sexual contact—male-female, female-female, adult-child—used as the universal social solvent. Anything that arouses the interest of more than one bonobo results in sex. Unlike common chimps, bonobos often have sex face-to-face; like them, the males have huge testicles, because the females of both species are serially promiscuous. It’s a sperm war: the more sex, the more partners, the better chance of raising your own offspring.

All of this fascinates us, and why shouldn’t it? Here are two species, closer to us than they are to the gorillas and with whom we share all but 1.5 percent of our genetic material, whose behavior is both like and completely unlike our own. But chimps and bonobos are no mere pit stops on the way to becoming human. Since our paths split from a common ancestor five million years ago, the genomes reveal that chimps have evolved more than we have (meaning that more of their genes have changed as a result of selective pressure than ours). Also, they are much more genetically diverse than humans, suggesting that they were once common and we were rare. Whatever small genetic shifts allowed us to stand on our hind legs, freeing our hands to pinch and grip, and our brains to grow, it isn’t a lack in the other species, just a difference. And, as Darwin once expressed it, a difference of degree, not of kind.

There are fewer than two hundred thousand chimps and bonobos left in the wild. The start of their decline predates human intervention, but we haven’t helped: more are eaten as bushmeat each year than are kept in all the world’s zoos. Imagine a world without chimpanzees. It’s precisely because we can, and they can’t, that we should save them.

Cicada

An insect that counts

Nobody really understands how they do it, but some species of cicada match their yearly life cycles to prime numbers, that is, numbers that can only be divided by themselves and one: 2, 3, 5, 7, 11, 13, 17, etc.

Prime-number cicadas, or magicicadas, from the Greek magos meaning “magician,” are found only in the eastern United States, and their nymphs spend years below ground feeding on tree roots. They only reappear to mate every thirteen or seventeen years.

The reason for this mathematical precision is to avoid even–numbered (and therefore predictable) breeding cycles, which their predators could match. By ensuring that trillions hatch on a single evening, but at unpredictable times, they literally swamp their predators, who gorge themselves until they can’t face any more, without damaging the cicada population. There are thirty different broods, each of which is timed to hatch at a different time. The thirteen- and seventeen-year cycles only coincide once every 221 years.

AUSTRALIAN CICADAS INCLUDE THE GREEN GROCER, THE FLOURY BAKER, THE DOUBLE DRUMMER, THE CHERRY NOSE, AND THE BLADDER.

In their long underground imprisonment, the larvae use their droppings to create waterproof cells, to help protect them from flooding. Even so, an estimated 98 percent perish before they feel the urge to hatch. Those that do survive slough off their childhood form and mate furiously. Most are dead within two weeks, providing a huge nitrogen boost for the forest floor.

Cicadas are easily the loudest insects, but it is only the males who sing, and usually only on warm summer days. Some species hit 120 decibels, equivalent to standing in the front row of an AC/DC concert. They can be heard nearly a mile away. Cicadas don’t rub their legs like grasshoppers, but make a series of clicks by buckling a pair of membranes, called tymbals, in their abdomens, in the same way we play a wobble board. Their bodies amplify the vibrations.

They often sing in large groups, which makes it impossible for birds to locate individuals, but the main function of the song is to attract a mate (although some have a protest song, which they use if you prod them). Each species has its own distinctive set of calls, which the females’ ears tune in to.

The nineteenth-century French entomologist Jean-Henri Fabre tried to demonstrate that cicadas were deaf by firing a cannon toward a tree full of them. Their song didn’t change, but not because they were deaf. The sound of the cannon was meaning-less to them: you can’t mate with heavy artillery.

Because of their apparent ability to be reborn from the ground, cicadas have come to represent resurrection and immortality in many cultures. In Taoism, they are symbols of tsien, the soul that leaves the body at death.

In ancient Greece, they were kept as pets. Plato tells a story of how they were once men whose devotion to music was so great that they wasted away, leaving only their music behind. Aristotle, on the other hand, was fond of eating them fried. Cicadas are still eaten across Asia and Africa and in Australia. Native Americans deep-fry them and eat them like popcorn. They are surprisingly meaty and taste like asparagus.

Comb Jelly

Gooseberries with lovely eyelashes

Around 550 million years ago, animal life came in just four varieties: worms, sponges, jellyfish, and comb jellies. The worms splintered into many different branches but the sponges and the jellies have changed little.

Early naturalists couldn’t decide if jellies were animals or not, so Linnaeus compromised by grouping them together as zoophytes or “animal plants.” Comb jellies are particularly plantlike to look at, and their common names—sea gooseberry, sea walnut, melon jelly—have a distinct fruit-and-vegetable flavor. But they are unquestionably animals, and carnivores at that—gobbling up crustaceans, small fish, and one another with what looks like single-minded dedication. Yet they have no brain—and no heart, eyes, ears, blood, or bones, either. They are just a lot of mouth.

Most comb jellies are spherical or bell-shaped, ranging in size from no wider than a matchstick to longer than a man’s arm. Ninety-five percent of a comb jelly is water; the rest is made of mesoglea (“middle glue”), a fibrous collagen gel that acts as muscle and skeleton rolled into one. To the casual observer, they look a lot like jelly-fish: in fact the two are from completely different phyla and are about as closely related to each other as human beings are to starfish.

COMB JELLIES ARE ONE OF THE OCEAN’S MOST ETHEREAL SIGHTS. THE BEATING OF THE CILIA DIFFRACTS THE LIGHT, MAKING THE COMBS LOOK LIKE EIGHT SHIMMERING RAINBOWS.

The comb jelly phylum is called Ctenophora (pronounced “teen-o-fora”) from the Greek ktenos (comb) and phora (carry). Unlike jellyfish, which propel themselves by contracting their bodies, ctenophores move by rhythmically beating their eight combs—rows of many thousands of hairlike cilia (Greek for “eye-lashes”). Also unlike jellyfish, comb jellies don’t sting. Instead, they have long, retractable tentacles covered in colloblasts, special cells that exude sticky mucus to trap their prey. They also have anal pores (real jellyfish use their mouths as bottoms), which nestle next to a gravity-sensing organ called a statocyst that tells them which way is up. While jelly-fish can regenerate a missing tentacle, half a comb jelly regenerates into a whole animal. Comb jellies also have a simpler reproductive system. Most are hermaphrodites, capable of producing eggs and sperm at the same time (up from the gonads, out through the mouth) and—

theoretically—of fertilizing themselves. They generally just release thousands of eggs and sperm into the water. Their young can breed as soon as they hatch.

Comb jellies are thought to be more numerous than any other creature of their size or larger. They aren’t great swimmers and are frequently swept into great, dramatic swarms, which pose a devastating threat to fishermen.

BEFORË’ BLIND DATE

If the egg of a Beroë ovata is entered by more than one sperm, the nucleus takes its time to choose the sperm that fertilizes it, sometimes going back to one it inspected hours earlier.

“He loves me, He loves me not. . . .”

The collapse of commercial fishing in the Black Sea in the 1990s has been blamed on an American comb jelly, Mnemiopsis leidyi, that arrived as a stowaway in a U.S. ship’s ballast tank. Now known as “the Monster,” it can produce eight thousand offspring a day. The Black Sea population weighs more than a billion tons, vacuuming up all the plankton that once fed the local anchovies. The Monster has also invaded the Caspian, threatening the caviar sturgeon. In 2001 a cannibalistic comb jelly, Beroë ovata, was introduced to hunt down and slaughter its beautiful but remorseless relative.

Coral

Sea skeleton

Corals share their closest family ties with jellyfish. It’s hard to imagine two more different-looking animals, but they are both members of the Cnidaria phylum (from knide, Greek for “stinging nettle”). Coral looks far more like a colorful, baroque relative of the seaweeds, but close examination reveals it as an animal, or rather a host of animals, as each frond is composed of thousands of tiny individual polyps, rather like miniature sea anemones (another relative). Each polyp has a fringe of stinging tentacles, a bottom-cum-mouth, and a stomach, just like their cousins. But they do something that the others don’t: they build reefs, the rainforests of the ocean.

By sucking in seawater, polyps extract the elements they need to lay down a solid base of calcium carbonate. This base is added to gradually, at about an inch a year. This provides a cuplike shelter for each polyp to hide in and keeps them moving upward toward the light. Coral polyps grow rock in the same way humans grow bones. Eventually, as millennia pass, it becomes a reef, an intricate subterranean city where two-thirds of all the oceans’ species live. If you gathered all the corals reefs in the world together they would cover an area the size of Texas.

CORAL DOESN’T AGE AS WE DO; MOST OF ITS CELLS ARE THE EQUIVALENT OF STEM CELLS IN A DEVELOPING HUMAN EMBRYO, ALLOWING EVEN A SMALL FRAGMENT TO REGENERATE INTO A WHOLE POLYP. SOME POLYPS MAY BE MORE THAN A CENTURY OLD.

Corals don’t manage this all by themselves. They have evolved one of the most mutually beneficial partnerships on the planet, with tiny algae called dinoflagellates (Greek for “whirling whips,” which describes their method of propulsion), small enough to live, two million to the square inch, in their skin. The coral polyps catch microscopic organisms with their tentacles, and the waste products (mostly carbon dioxide) feed the on-board algae. In return, the algae give the polyps their striking colors, and produce most of their energy by photosynthesizing sunlight. This is why you find most corals in shallow, clean, sunlit water. The algae even make a sunscreen that protects the polyps, allowing them to keep working all day. And it is hard work: reef-building corals use up proportionately two and a half times as much energy as a resting human.

A FAMILY GROUP

“With friends like these, who needs anemones?”

Coral’s relationship with algae is not without its tensions. If the algae can get food more easily elsewhere, as happens when the reef silts up or becomes too warm or polluted, they will leave, “bleaching” the polyps white and condemning them to death. In the record-breaking heat of 1997 and 1998, a sixth of the world’s coral reefs bleached. It is now estimated that a tenth of all the world’s reefs are dead, and if the carbon levels in the oceans continue to rise, the rest will follow by 2030. Coral reefs are on the front line in the war against global warming.

Indirectly, coral helped Charles Darwin refine his ideas about evolution. Although he had no idea about the symbiotic relationship with algae, his first scientific book after returning from the voyage on the Beagle, published in 1842, was an account of the formation of coral reefs. He theorized (correctly) that atolls were formed by undersea volcanoes slowly sinking under the surface of the ocean, leaving the ring of coral still growing upward toward the light. The long process of geological change implied by this confirmed his hunch that constant change was at work all over the biological kingdom.

Cow

Field factory

Watching cows placidly munching away in a field it’s hard to imagine the fierce creature that so terrified Julius Caesar: “Their strength and speed are extraordinary; they spare neither man nor wild beast which they have espied . . . not even when taken very young can they be rendered familiar to men and tamed.” He was wrong, as it turned out. Roman cows were the descendants of these same wild oxen, known as aurochs, which had originated in India and were first domesticated in Mesopotamia, six thousand years earlier. Although sheep, goats, and pigs were already being raised for meat, the domestication of oxen was a turning point: the moment farming became a business. Keeping cows was about more than feeding your immediate family. The word “cattle” originally meant “property”—cows were an indicator of wealth.

COWS ARE FED MAGNETS TO COPE WITH “HARDWARE DISEASE,” THE DAMAGE CAUSED BY THE BITS OF WIRE, STAPLES, AND NAILS THAT THEY REGULARLY SWALLOW. THE MAGNET SITS IN THE FIRST PART OF THE STOMACH AND LASTS THE COW’S LIFETIME.

As a potential candidate for domestication, Bos primigenius ticked all the boxes. It was large, ate grass, and tasted delicious. You could say the same about bears, hippos, and rhinos, but wild oxen herded together rather than ran away or attacked when threatened. And although bulls are fierce, the herd has such a strong hierarchy that most of the animals are used to being docile and obedient. Bears and hippos don’t take orders. Nor do they produce gallons of milk, every day, without complaining. Cows quickly became our most reliable machines, converting rough grass into high-protein food and drink.

Cow farts are not destroying the world; unfortunately cow burps are. An average cow burps 600 pints of methane a day, and this is responsible for 4 percent of worldwide greenhouse gas emissions and a third of the U.K.’s. Livestock farming in general creates 18 percent of all man-made greenhouse gases—more than all the cars and other forms of transport on earth. Cows produce one pound of methane for every two pounds of meat they yield. Work is under way to produce a methane-reducing pill the size of a man’s fist, called a bolus, which would dissolve inside the cow over several months. Even so, cattle farming is costly. To make one pound of beef requires thirteen hundred square feet of land, six times as much as to produce the equivalent weight in eggs and forty times what it takes to grow a pound of spuds.

On the other hand, cows have many uses beyond the obvious. As well as helping us tame disease through vaccination (vacca is Latin for “cow”), cows have put their whole bodies at our disposal. Pliny the Elder once recommended a concoction of warm bull’s gall, leek juice, and human breast milk as a cure for ear-ache. Hippolyte Mège-Mouriés used sliced cow’s udders, beef fat, pig’s gastric juices, milk, and bicarbonate of soda in his original recipe for margarine. Cows’ lungs are used to make anticoagulants, their placentas are an ingredient in many cosmetics and pharmaceuticals, and cow septum (the bit of cartilage that divides the nostrils) is made into a drug for arthritis. Their blood is made into glue, fertilizer, and the foam in fire extinguishers. Brake fluid is made from their bones. Sweden even has a cow-powered train that runs on methane harvested from the stewed organs. One cow’s worth will fuel a two-mile journey, excellent news for the Swedish carbon hoofprint.

Crane

Oldest, tallest, loudest, highest

Cranes are record-breakers. The crowned cranes (Balearica regulorum and pavonina) are direct descendants of the earliest known birds, whose fossils date back to the early Eocene, more than fifty-five million years ago. The sandhill crane (Grus canadensis) holds the record for the longest surviving species of bird: a nine-million-year-old leg bone found in Nebraska is indistinguishable from that of a modern sandhill. The oldest recorded bird was a Siberian crane (Grus leucogeranus) called Wolf who died in 1988, aged eighty-three, at the Wisconsin International Crane Center. At six feet tall, the Sarus crane (Grus antigone) is the tallest flying bird and the Eurasian crane (Grus grus) flies higher than any other, reaching 32,000 feet. At that altitude, they are invisible from the ground, but are so loud they can still be heard.

There are fifteen species of crane and they are found everywhere except South America and Antarctica. Their beauty and elegance have enchanted human beings in every culture. They figure in prehistoric cave paintings, and Homer writes of their “clangorous” sound in the Iliad. According to Roman fables, the god Hermes was inspired to invent writing by the letter shapes that flying cranes made in the sky.

Cranes seem almost human. They are sociable, mostly monogamous, and spend years raising their children. They have long memories and complex communication systems, using more than ninety physical gestures and sounds.

They are also the avian world’s best dancers, using elaborate choreography to develop social skills when young and for courtship when older. In a flock, once one crane starts dancing, all the others join in, bowing, leaping, and running and even picking up small objects to toss into the air.

There is evidence for imitative human crane dances from as early as 7000 B.C. In ancient China and Japan, among the Ainu of Hokkaido, the shamans of Siberia, and the BaTwa pygmies of central Africa, the crane dance is a key ritual. Plutarch even records that Theseus celebrated his defeat of the Minotaur by dancing like a crane.

THE DEMOISELLE CRANE (ANTHROPOIDES VIRGO) IS THE SMALLEST SPECIES, INTRODUCED TO FRANCE FROM RUSSIA IN THE EIGHTEENTH CENTURY. THEIR DAINTINESS CHARMED MARIE ANTOINETTE AND SHE NAMED THEM “DEMOISELLE,” MEANING “YOUNG LADY.”

Cranes have also left their trace in language. Cranberries are named after them, from the similarity between the stamen of the plant and the bird’s bill. The word “geranium” is from geranos, Greek for crane: its seedpod resembles the bird’s noble head. And “pedigree” comes from the French phrase pied de gru, “foot of a crane,” as family trees look a little like birds’ feet.

Eight of the fifteen crane species are endangered, two of them critically. In America in 1941, the number of whooping cranes (Grus americana) dwindled to 20 but has since recovered to more than 450. The breeding program involves “isolation rearing,” where crane eggs are hatched and reared using hand puppets, humans in crane costumes, and taped calls.

THE CRANE HORN

Sound travels more than 3 miles.

Cranes are one of the loudest of all birds and in most cultures they are named after their distinctive call.

Cranes were once widespread in Britain—almost every county has a Cranwell, Cranbourne, Cranley, or Cranford—but they are now Britain’s rarest breeding bird. A tiny colony established itself in Norfolk in the 1980s, the first to do so in 350 years. Its precise location is a closely guarded secret.

Dog

Wolf with talent

The ancestors of dogs were the earliest known carnivores. Dogs evolved from wolves—gray wolves are their closest living relatives—and were first kept by humans between twelve thousand and fourteen thousand years ago. It’s not known whether it was a single event that spread, or if it occurred independently in different regions. While some think dogs invited themselves along by scavenging human rubbish dumps and becoming gradually less scared of humans, others think humans adopted wolf pups and that natural selection favored those with milder temperaments. The famous breeding experiment begun by Russian scientist Dmitri Belyaev in 1959 showed it took wild silver foxes only twenty years to transform into tame dogs (see under Fox).

THE FUEGIANS . . . WHEN PRESSED IN WINTER BY HUNGER, KILL AND DEVOUR THEIR OLD WOMEN BEFORE THEY KILL THEIR DOGS: A BOY, BEING ASKED BY MR. LOW WHY THEY DID THIS, ANSWERED, “DOGGIES CATCH OTTERS, OLD WOMEN NO.”

CHARLES DARWIN

Today, there are nearly four hundred breeds of domestic dog but all belong to the same species: Canis familiaris. In theory, a two-pound Chihuahua only a couple of inches high can mate with a Great Dane more than three feet tall or a 150-pound Saint Bernard. The vast diversity of dogs is down to humans carefully selecting valuable inherited traits but often encouraging unusual ones such as dwarfism or lack of a tail that, in the wild, might prevent a dog surviving long enough to reproduce. Specialized hunting skills were especially sought after. Springer spaniels have the ability to “spring,” or startle, game. The dachshund’s sausagelike body enables it to pursue badgers into their burrows (“badger” is Dachs in German). Labrador retrievers were bred to retrieve fishing nets in Newfoundland. There are harehounds, elkhounds, and coonhounds; leopard dogs, kangaroo dogs, and bear dogs; there is even a sheep poodle. Poodles were originally used for duck hunting: the word comes from the German for “to splash in water.” But dogs are bred for all sorts of reasons. Louis Dobermann, a German night watchman, produced his namesake for watchdog purposes in the late 1800s. Toy varieties, such as the Pekingese, were raised in ancient China as “sleeve dogs”—kept inside the gowns of noble-women to keep them warm.

A DOG’S LIFE

The now extinct turnspit dog or “underdog” was a kind of terrier bred to work in the kitchen. It was long-bodied and short-legged, rather like a corgi with floppy ears. Turnspits worked in pairs, each doing alternate days.

There’s no question about it: unlike cats, dogs are useful. A dog’s nose has 220 million olfactory cells, humans a mere 5 million. A dog’s sense of smell is not only hundreds of times better than a human’s: it’s four times better than the best man-made odor-detecting machines. Dogs can be trained to find almost anything by smell: explosives, drugs, smuggled animals, plants, and food, landmines under the ground, drowned bodies under the surface of lakes. They can even smell cancer. Doctors in California have found that both Labradors and Portuguese water dogs can detect lung and breast cancer with greater accuracy than state-of-the-art screening equipment such as mammograms and CT scans. The dogs correctly identified 99 percent of lung cancer sufferers and 88 percent of breast cancer patients simply by smelling their breath. Dogs wag their tails when sad as well as when happy. Cheerful dogs wag their tails more to the right side of their rumps. Morose dogs wag to the left. Help them wag to the right: they deserve it.

Dolphin

Leave us alone

We haven’t done dolphins any favors. The wilder shores of hippie speculation they have inspired—their brains are more complex than ours; their language is more sophisticated; they have a society dedicated to peace and free love; they are extraterrestrials with fins—reveal more about us than them. This is not to under-mine their utter fabulousness, just to remind us that they are wild animals, with their own agendas and priorities. They can do things we can only dream of (and—just maybe—they feel the same about us).

Take echolocation, their system of marine navigation. Dribble a teaspoon of water into a pool and they will locate the sound with pinpoint accuracy. They can discriminate between objects made from wax, rubber, or plastic. They can even tell the difference between identical-looking brass and copper discs. Fish, not noted for their quietness (herrings fart nonstop), don’t stand a chance.

Their language skills are more difficult to assess. Dolphins are famously talkative—despite having no vocal cords. The clicks, whistles, groans, squeals, and barks all come from sacs in their nasal passages—as many as twelve hundred per second. Each dolphin has a unique signal whistle, an “I’m Flipper” tag, which it repeats constantly. They also imitate other dolphins as a way of gaining their attention, rather in the same way as doing an exaggerated impression of a friend in a crowded bar means they are more likely to turn around. The whistle signals show that they communicate, but they are a long swim away from being a language.

A DOLPHIN’S SKIN IS SHED AND REPLACED EVERY TWO HOURS TO MAXIMIZE STREAMLINING.

Dolphin play is highly complex, and they learn fast. They have a striking ability to follow extraordinarily complicated human commands, and can recognize themselves in a mirror. They can even use tools: when hunting among sharp coral they attach bits of sponge to their snouts as safety masks. Legends of their helpfulness to gods and humans are threaded through Greek and Roman myth, and contemporary accounts of dolphin rescues are common. In small fishing communities, dolphins are known to herd shoals of fish into nets in return for a few thrown back and a friendly wave. It’s hard not to love their big smiley faces.

But there is another side. For all the foreplay and nuzzling, females are frequently coerced into sex by groups of males. Schools of dolphins batter porpoises to death for no obvious reason, and occasionally practice infanticide. In a comprehensive study of wild dolphins that seek out human company, three-quarters showed aggression, which sometimes led to serious injury, and half indulged in misdirected sexual behavior with buoys and boats as well as humans. Given that an average male bottlenose weighs 560 pounds and has a foot-long, solid muscle penis that ends in a prehensile hook agile enough to catch an eel, you wouldn’t want to give off the wrong signals.

NOSE SONAR

Whistle signals are focused and directed by the melon (oil-filled to the same density as seawater) and the returning signal is picked up by the lower jaw, also oil-filled, and teeth.

Tiny time differences in signals hitting the jaw “receivers” allow them to pinpoint direction.

This same report concluded that contact with us almost always means injury and suffering for the wild dolphin. It’s worth bearing that in mind when considering the benefits of wildlife tourism and dolphin therapy. Of course, the idea of swimming with dolphins is attractive and there is evidence that it does have therapeutic value. But we gain just as much (and maybe more) by standing on a boat watching them through binoculars, reveling in the fact that they are where they belong, doing what they do best.

Donkey

A natural source of Viagra

Donkeys’ milk is a wonder substance. Country people in India have always sworn by it as a baby food, but chemical analysis has recently revealed it is full of oligosaccharides, carbohydrates with powerful immuno-stimulant properties. It has been tested in cases of AIDS and cancer, and some claim the milk has an effect similar to Viagra.

Donkeys were first domesticated in Ethiopia and Somalia about six thousand years ago. The modern donkey is the same species as the African wild ass (Equus asinus). It is the only domesticated animal to have originated in Africa. They were used for transport long before horses, which were originally bred in Asia purely for their meat.

Ancient Egyptian tombs show that donkeys were the Porsches of the Nile delta: the more donkeys, the higher your status. Herds of a thousand or more were not uncommon. With donkeys came trade: their ability to carry 30 percent of their body weight without complaint opened up the ancient world.

The original desert truck

The word donkey is surprisingly recent—it wasn’t around when the King James Version of the Bible was written in 1611—and probably originated in the late eighteenth century to avoid the growing confusion between ass and arse. According to the Oxford English Dictionary, donkey was originally pronounced to rhyme with “monkey” and is thought to come from “dun,” meaning brown or gray.

A DONKEY IS LIKE A HOUSEWIFE. IN FACT, THE DONKEY IS A SHADE BETTER, FOR YOU’LL NEVER CATCH THE DONKEY BEING DISLOYAL TO HIS MASTER.

RAJASTHANI SCHOOL TEXTBOOK

A male donkey is called a jack or jackass; a female donkey is called a jenny or donkeyess. The personality of a donkey is called its donkeyship.

Donkeys have sixty-two chromosomes (sixteen more than humans) and can be crossed with horses or zebras. The offspring of a male donkey and a female horse is called a mule. The male mule is called a john and a female mule a molly. The off-spring of a male horse and a female donkey is called a hinny. Zebras crossed with donkeys are called zee-brasses and zonkeys. Only one in ten thousand of these hybrids are fertile.

Donkeys use their ears to communicate and cool down. They are much longer than a horse’s (hence the phrase “donkey’s years”—a corrupted version of “donkeys’ ears”).

Donkeys have a reputation for stubbornness; in fact, they are highly sensitive to danger and rather sensible. Unlike horses, which bolt when spooked, donkeys stand rooted to the spot, braying loudly, and are the only animals of their size that won’t back down when confronted by a lion. In Africa, guard donkeys are used to protect cattle. Dogs are instinctively scared of donkeys: they have a surprisingly accurate kick.

By 1939 there were only a hundred donkeys left in England. There are now about ten thousand—eight hundred are licensed to work on beaches and 75 percent of them live in donkey sanctuaries.

Every donkey has a dark cross on its back that is supposed to date from Christ’s entry into Jerusalem. Before it became associated with Christ, the donkey was identified with the Egyptian sun god, Ra, and Dionysus, the Greek god of wine and theater. Until the mid–nineteenth century, Santa Claus always rode a donkey.

Dead donkeys are lucky. You should jump over them three times. Or make a sandwich out of their hair to cure a cough. Or sprinkle their toenail clippings over your enemies. Or pop their heads in the oven: cephaleonomancy is divination using a roasted donkey’s head. In 1869 a donkey was served for dinner at high table in Sidney Sussex College, Cambridge. One of the dons remarked that it tasted “rather like swan.”

Eagle

Omnipotent omnivore

Eagles belong to the family Accipitridae, from the Latin accipiter, a “bird of prey.” In English, an accipiter is a “nose-bandage” from its resemblance to the beak or claw of a hawk. Not everyone agrees what an eagle is; no one knows how eagle species are related to one another and the evolution of eagles is poorly understood. Eagles are defined by what they are not. According to one professional definition, an eagle is “a large or very large diurnal raptor which is not a kite, vulture, hawk, buzzard, or falcon.” In all eagle species, females are larger than males: the more aggressive the species, the larger the discrepancy.

EAGLES LAY CLUTCHES OF TWO EGGS, BUT THE FIRST CHICK TO HATCH USUALLY KILLS ITS SIBLING, EVEN WHEN FOOD IS ABUNDANT. NO ONE KNOWS WHY.

An eagle’s eye can be up to twenty times larger in proportion to its body than a human eye. They are so big in their sockets that there is little room for them to move: like owls, an eagle has to move its whole head to look around. Nonetheless, the visual acuity of an eagle is up to eight times better than a human’s. An eagle can spot a rabbit from two miles away. As an eagle swoops down on its prey, the muscles in its eyes continually adjust the curvature of the lens to maintain sharp focus and accurate depth perception throughout the attack. Eagles of the soaring variety must wait until the air is warm enough to create thermals. The heavier the eagle, the later in the day it begins to hunt. Eagles, however, can hardly be described as heavy. A golden eagle (Aquila chrysaetos) is seven and a half feet wide but weighs less than nine pounds. A bald eagle’s (Haliaeetus leucocephalus) feathers weigh more than twice as much as its bones. An eagle’s dive reaches speeds of 200 mph, but only about one in four such attacks are successful.

THE TWO-HEADED EAGLE FEATURED ON MANY EUROPEAN FLAGS WAS A SYMBOL OF THE BYZANTINE EMPIRE: ONE HEAD REPRESENTED ANCIENT ROME, THE OTHER, “NEW ROME,” OR CONSTANTINOPLE.

Some eagles have given up on the exhausting business of roaming the azure yonder, falling like a stone and missing. They prefer to sit about biding their time. Many reptile-eating (and some fish-eating) eagles perch in trees in a lordly manner, waiting for their prey to scuttle by. They then drop straight onto them from a sitting position. The lesser-spotted eagle (Aquila pomarina) neither falls like a thunderbolt nor watches imperiously. It walks around looking for frogs to eat. Eagles will eat anything, dead or alive. Not just rodents, reptiles, birds, and fish but ants, termites, dead elephants and whales, locusts, baby seals, crabs, snails, sloths, snakes, and monkeys. Martial eagles (Polemaetus bellicosus) eat baboons. Golden eagles enjoy caribou calves. Steller’s sea eagle (Haliaeetus pelagicus) is partial to seal pups. Crowned hawk eagles (Stephanoaetus coronatus) eat man-drill monkeys and can kill a bushbuck four times their own size. Both serpent eagles and snake eagles catch snakes. Serpent eagles fly off with the snake dangling from their legs, whereas snake eagles swallow them whole, head first. They then fly back to the nest, where the snake eaglet grasps the tail of the snake and hauls it out of its parent’s mouth like a string of handkerchiefs. On a less grisly note (and despite its unnerving name), the favorite food of the vulturine fish eagle (Gypohierax angolensis) is fruit from the oil palm tree.

Echidna

Spiny not-anteater

What has a birdlike beak, spines like a hedgehog, the eggs of a reptile, the pouch of a marsupial, the life span of an elephant, and a penis like a four-staved club? Enter the echidna, Australia’s almost-anteater. Like anteaters the echidna has a long sticky tongue, powerful front legs, and a huge appetite for social insects. But there the similarities end. The echidnas aren’t even marsupials, they’re monotremes (one-holed creatures), so named because, like birds and reptiles, they have a single hole, or cloaca, for excretion and reproduction. Along with the platypus, the four species of echidnas are thought to be the only descendants of the southern mammals that split from their northern counterparts before the supercontinent known as Pangaea began to break apart, 180 million years ago in the Jurassic. This makes them the oldest surviving mammal group.

The short-beaked echidna (Tachyglossus aculeatus—“thorny fast-tongue”) is the most widely distributed mammal in Australia. They are shy, solitary creatures that live in large undefended territories (no one has observed an echidna fight). They have two predator-escape strategies: the spiky ball and the sinking ship (echidnas can dig straight down until only their spines are showing). They have the coldest blood temperature of any mammal, and can conserve energy by dropping their body temperature to 39°F and taking only one breath every three minutes. To warm up, they can lie flat like a spiny rug in the sunshine. To cool down, it is thought that their spines dissipate heat like an elephant’s ears. They can live for fifty years.

THE EGG AND POUCH TRICK

Mating takes place in the winter when a group of males form a slow-moving “love train” behind a pheromone-emitting female. This shuffling procession can last for more than a month. As soon as she’s ready, the female clings to a tree trunk with her forelimbs while the males dig a ten-inch-deep, doughnut-shaped trench around the tree. They then compete for mating honors, gently pushing one another around with their heads. The winner lies on his side in the trench partly underneath the female and, unsheathing his curiously configured member, mates, pressing his belly against hers. A single grape-sized egg follows three weeks later, hatching a wriggling, beanlike puggle. After eight weeks of rapid growth, the puggle is transferred to a burrow, just as the spines start to show.

AN ECHIDNA’S NEOCORTEX, ASSOCIATED WITH REASONING AND PERSONALITY IN HUMANS, ACCOUNTS FOR HALF THE VOLUME OF ITS BRAIN, COMPARED TO ONLY A THIRD IN THE “HIGHER” MAMMALS. NO ONE KNOWS WHAT ECHIDNAS USE IT FOR.

As for the other species, there can be few animals more mysterious than the long-beaked echidna (Zaglossus bruijni—“de Bruijn’s long-tongue”) of New Guinea. Here’s all we know: its body and nose are twice the size of its cousin’s; it’s furrier; it mainly eats earthworms speared with special spines on its tongue and then sucked up like spaghetti; it’s nocturnal; it snuffles a lot. That’s it: everything else is conjecture. We think there are three subspecies: one (rather sweetly named after Sir David Attenborough) is restricted to a single (dead) specimen, found in 1961. The other two are endearing, inquisitive creatures that look like four-legged kiwis and tame easily. This has made them easy to hunt, and since the arrival of Europeans, the taboo against killing a once sacred animal has disintegrated. Papuan tribesmen track them with dogs and serve them roasted as a delicacy. How many are left? We have no idea. . . .

Eel

Freudian slippery

Nobody knows where the word eel comes from. Until the 1920s, nobody knew where eels themselves came from. Aristotle insisted they arose spontaneously from rotting seaweed. Pliny the Elder thought they rubbed against rocks and that the shreds of their skin came to life. Other imaginative suggestions included the dew of May mornings, the gills of fish, and horsehairs falling into the water. The astonishing life cycle of the eel was first revealed to the world by the Danish oceanographer Johannes Schmidt (1877–1933) who, in 1905, was commissioned by his government to locate their spawning grounds. Given one small ship, he set off to trawl the oceans of the world. It took him sixteen years.

EELS ARE ONE OF VERY FEW SPECIES OF FISH THAT CAN SWIM BACKWARD. THEIR THICK COATING OF MUCUS MEANS THEY CAN ALSO TRAVEL ON LAND AS WELL AS IN WATER. THEY MAKE THEIR WAY INTO FIELDS AND GARDENS TO SNACK ON YOUNG PEAS AND BEANS.

It seems that all European and American freshwater eels (Anguilla anguilla and rostrata) are born as saltwater fish in the Sargasso Sea, a strangely calm area of the North Atlantic around Bermuda, two million square miles in extent and clogged with sargassum weed. This is kept afloat by berrylike bladders: hence the name from sargaço, an old Portuguese word for “grape.” From here, the eel larvae are carried by the Gulf Stream three thousand miles across the Atlantic to Europe, where, on entering the mouths of rivers, they miraculously transform into freshwater creatures. They don’t aim at a particular river: they hit the coast in a broad band and swim up whichever one they encounter—so rivers with wide west-facing estuaries like the Severn get lots of them. They will go to any length to reach their goal, piling up their bodies by the tens of thousands to climb over obstacles. Once there, the eels live contentedly in rivers until they reach maturity. When this happens (between the ages of six and forty) they prepare to swim back to the Sargasso Sea again. They change dramatically: backs turn darker; bellies turn silver. They toughen up, storing fat, which they’ll need for the journey. Eyes enlarge, heads become pointed, nostrils dilate, the salt content in their bodies reduces, and their sex organs swell. Their gas bladder also changes to allow them to withstand pressures of a ton per square inch.

THE EEL REEL

Once back in the Sargasso, the females spawn and the males fertilize the eggs, after which they all die of exhaustion. Or so it is believed. Nowadays, “everybody knows” that eels are born in the Sargasso Sea but this has never been proved. No one has ever seen an eel spawn or seen one die there. Careful scientists prefer to call the Sargasso Sea the eel’s “presumed” breeding ground. Young eels have been found there, but neither live adults nor their eggs. Not one eel has ever been bred in captivity. When you catch an eel, its reproductive system shuts down completely, as if deliberately keeping the secret. Sigmund Freud was determined to find the answer. He worked in Trieste cutting up hundreds of eels to see how their sexual organs worked. When he had finished, he published a thesis in which he concluded that all of his research was a waste of time. He was no nearer to understanding eels than when he first started.

Elephant

A giant hamster on tiptoe

Elephants are the largest living land animals and size is both the secret of their success and the reason they look the way they do. Elephants grew big to compete with the waves of antelopes and other ruminants munching their way across the grassy plains. To eat the coarse, woody vegetation the ruminants couldn’t manage required a big digestive tract and long legs. So they got bigger and by about two million years ago had spread all over the planet except Australasia and Antarctica.

AN ELEPHANT’S GAIT IS A BIT LIKE GROUCHO MARX’S: CROUCHING SLIGHTLY SEEMS TO HELP THEM TO MOVE THEIR BODIES MORE SMOOTHLY.

Size brought its challenges. Over-heating is a problem for large mammals: the elephant’s ears evolved to stop it boiling to death. Unlike the thick skin that covers most of their bodies, the skin on their ears is paper-thin. Each ear is the size of a single bedsheet and when it flaps, the airflow reduces blood temperature by up to 41°F. The skein of blood vessels acts like the grill in a car’s radiator. The pattern they make is unique to each elephant and can be used to identify them, like human fingerprints.

The other challenge is drinking, as kneeling down makes even a large animal vulnerable to attack. Elephants evolved the perfect solution, a 7-foot, 392-pound nose that contains a hundred times more muscles than we have in our entire bodies. Not only can a trunk suck up 8 pints of water, it also functions as an arm, hand, snorkel, and weapon. It is powerful enough to kill a lion with a single blow, yet the fingerlike lobes at the end can pick up a grain of rice.

Elephants’ tusks are large canine teeth—chewing teeth are nestled deep inside.

Despite weighing more than three tons, elephants still walk on tiptoe, like most mammals, but they are the only mammals with four forward-facing knees, needed to give them extra leverage when standing up. They can’t run or jump (to run all feet must be off the ground at once) but they can walk silently, reaching a top speed of 15 mph. They also use their feet to hear, picking up the very low-frequency calls (inaudible to humans) of other elephants from as far away as six miles. Males and females can’t understand each other’s calls, and the female vocabulary is much larger.

The “silent walk” is due to a layer of cartilage in their feet between the bone and the pad that acts as a shock absorber, with the outside of the pad hitting the ground before the center. The sound produced when the pad hits the ground is trapped in the air pocket under the foot.

Elephants are large-brained and clever: along with dolphins and some primates, they are the only animals that can recognize themselves in a mirror. They spend twelve years as calves and their development involves a lot of learned behavior—a young elephant has to be shown how to use its trunk. They have elaborate mourning practices and often visit and fondle the bones and tusks of the dead. The oldest elephant ever recorded was eighty years old, but most live for about fifty years. With few predators (other than man), the default elephant death is starvation caused by their teeth wearing out.

The closest living relatives of the elephants are the sea cows, and then the hyraxes, furry creatures that look like large hamsters. The common ancestor of all three was a giant hyrax, Africa’s primary herbivore until the ruminants arrived and set one branch of the family on the way to sprouting trunks.

Ferret

Dancing Prozac

Ferrets are the only member of the weasel family to have been domesticated, and their popularity as pets is on the increase. On the face of it, this is surprising. Their scientific name, Mustela putorius furo, translates as “musk-bearing stinking thief,” although most of this infamy is inherited. Ferrets are tame European polecats (from poule chat, “poultry cat”), a creature so despised by farmers and gamekeepers that it was hunted, trapped, and gassed to near extinction across most of Britain during the nineteenth century. Also known as the foulmart or stinkmarten, the polecat was the scourge of henhouses, but also helped keep the rabbit and mouse population in check. When they were originally domesticated, more than two thou-sand years ago, it was to exploit this natural aptitude.

UNTIL THE 1960S, FERRETS WERE USED TO CARRY CABLE TO INACCESSIBLE AREAS OF BOEING AIRCRAFT AS THEY WERE BEING BUILT. THEY WERE REPLACED, AS THEY OFTEN GAVE UP AND FELL ASLEEP HALFWAY.

Polecats and ferrets continue to hybridize easily, and, ironically, it is the wild “polecat” streak that makes the ferret a wonderful pet. Unlike dull, grass-chewing, social rodents like hamsters and guinea pigs, the domestic ferret has remained a solitary hunter, as pure a carnivore as the domestic cat. But ferrets have none of the aloofness of cats: they are as curious, bold, and responsive as puppies. You can teach a ferret to come to its name or take it for walks on a leash. The inquisitive streak that makes it lethal in a rabbit burrow is hugely diverting when it’s ferreting around in the backyard. One particular maneuver, the “war dance,” involves the ferret leaping backward and sideways, chirping with excitement. They are particularly valued as pets by single professionals, as they sleep for eighteen hours and make hardly any noise, but are always ready with a cheerful fuss when you do return home.

CANNY CUNICULUS CATCHER

Ferrets have been used as a humane, low-tech method of controlling rabbits since Roman times.

There are downsides. Despite keeping their quarters very clean, they do smell and even a well-looked-after ferret is probably a little too feral for indoors. Also, their natural high spirits mean they have little in the way of common sense. In a house they will disappear in holes in walls, behind doors, into cup-boards, and down the backs of sofas and appliances like dish-washers, where they can get squashed. Nor do they have a homing instinct if they escape. Female ferrets (jills) can get sick if they aren’t mated when in season. The simplest way is to keep a sterilized male (hoblet) to service them: an unfettered male (hob) might father fifteen kits a year. But be warned: ferret sex is nasty, brutish, and long. The hob is much larger than the jill and has a penis shaped like a hockey stick that locks inside her for several hours, while he indulges in some fairly rough dragging and neck-biting. Rather like female cats, jill ferrets seem to need a measure of unpleasant foreplay before they release their eggs.

Ferrets also suffer from some very human ailments. Cancer of the lymphatic system and pancreas is relatively common, and they are prone to stress-related illnesses and bouts of depression, particularly if separated from a companion. Often they will refuse food and mope for weeks. This makes them rather easier to empathize with than, say, a gerbil, and has led to their successful deployment in “pet therapy.” An hour spent with a ferret seems to act as a positive tonic for the elderly, the depressed, and children recovering from severe illnesses.

Flea

Spring-loaded sex god

The malarial mosquito has claimed more human lives, but for Europeans at least, the horseman of the apocalypse rides a flea. None of the waves of bubonic plague that have swept Europe and Asia would have been possible without the odd personal habits of Xenopsylla cheopis, the Oriental rat flea. Like most of the eighteen hundred species included in the Siphonaptera order (“wingless siphons”), the rat flea is always hungry and not very fussy about where it eats. Plague starts in rodents (usually marmots) but is spread by the fleas that feed on them. Plague bacteria reproduces so quickly they block the flea’s digestive passage. Very soon this produces a lot of hungry fleas, their mouth-parts dripping with infected blood, ready to bite any mammal within striking distance, as more than a billion humans have found out to their cost.

PET SHOPS WOULD BE BEREFT WITHOUT FLEAS: MORE THAN $1 BILLION A YEAR ARE SPENT ON ANTI-FLEA PRODUCTS IN THE UNITED STATES ALONE. PLINY THE ELDER’S SOLUTION WAS CHEAPER: COLLECT THE SOIL UNDER YOUR RIGHT FOOT WHEN YOU HEAR THE FIRST CUCKOO OF SPRING AND SPRINKLE IT OVER THEM.

Being unfussy gives fleas an advantage. Our very own species, Pulex irritans, has largely been banished by better hygiene but can still be found on pigs. The fleas on your dog are probably cat fleas, as they are the most common and will live on most mammals or even a passing lizard. In fact, the only consistent requirement for fleas is that an animal sleeps in a den or nest. That’s because fleas’ eggs aren’t attached to their host. They fall off, hatch, and feast on the adult fleas’ droppings. This is highly efficient: as a flea sucks its way through fifteen times its own body weight in blood a day, its other end feeds the blind wormlike larvae. Once they pupate, the cocoons can lie dormant for a year, waiting for our vibrations to hatch them.

Streamlined to move effortlessly through hair, covered in snaggable spines and combs, fleas are hard to remove and even harder to crush. Their legendary jumping skills aren’t even dependent on muscle strength. Wingless, they have turned the wing-hinge structure into a mechanical spring made from a rubbery protein called resilin. This clicks shut as the body plates compress, like a catch on a jack-in-the-box. When released, it pushes down on the leg tendons, achieving an acceleration that is fifteen times that of a space shuttle launching. The flea uses movement-sensitive hairs to calibrate precisely the distance and direction of its jump, and pumps air into special sacs in its legs to slow down before touchdown.

Impressive as this is, the real masterpiece of flea engineering is the penis. Proportionately the longest of any insect, it has so many hooks, springs, and spines that it’s been compared to a Swiss army knife. Unsurprisingly, it takes a long time to unfold, but then copulation can last for three hours—the equivalent of six weeks for a human. Adult fleas are ready for this marathon as soon as they emerge. No wonder a single pair of fleas can produce another fifty thousand in a month, or that Carl Djerassi, the creator of the contraceptive pill for humans, also developed one for fleas.

BUNNY LOVING

Rabbit fleas breed in sync with their host.

Fly

Sultan of sperm

Flies are insects with two wings. Mayflies, dragonflies, fireflies, and butterflies are not flies. There are one hundred twenty thousand known species of true fly (almost seven thousand in the U.K. alone) between them carrying more than a million species of bacteria. The common housefly (Musca domestica) is among the most dangerous animals in the world. It breeds in rubbish, sewage, and dung, and spreads tuberculosis, typhoid, cholera, dysentery, anthrax, and parasitic worms by excreting, walking, and vomiting on food.

Flies are prodigious breeders. In warm weather, the life cycle from egg to maggot to adult lasts just eight to twelve days. Theoretically, two flies that mate in April could produce 191,010,000,000,000,000,000 descendants by August: enough to cover the earth in a blanket of horridness forty-seven feet deep. But only a small proportion of flies are pests: most are essential for pollination and the recycling of decaying matter.

Flies have been much misunderstood throughout history. Arisotle confused the generations that followed him by implying flies had four legs and two “arms,” and this was repeated in academic texts for more than a thousand years as no one bothered to look at a fly and check. Only in 1688 did the Italian biologist Francesco Redi disprove what everyone also believed: that maggots spontaneously generate from meat.

Flies land on the ceiling by zooming in close, reaching up with their front legs, and flipping their whole body over backward. They walk around up there thanks to their sticky feet. These are covered in tiny hairs that produce a gluelike substance made of sugars and oils. They are also equipped with a pair of minute claws so they can detach themselves on departure.

Of the flies that are pests, among the most serious are fruit flies: every year they cause billions of dollars of losses in fruit, vegetable, and flower crops. Yet they are the most studied and the most fascinating flies of all. Cheap, easy to handle, and quickly anaesthetized, it is easy to tell males from females, and they breed extremely fast, so that many generations can be studied in a short time. The discovery of chromosomes, which won Thomas Hunt Morgan a Nobel Prize in 1933, stemmed from his work on fruit flies. It turns out that 61 percent of human diseases have fruit fly equivalents. Scientists who work on fruit fly genes (known as drosophilists) like to give appropriate names to their more unusual discoveries. Flies with the “Groucho” gene have more face bristles than normal and “Maggies” have arrested development, like the baby in The Simpsons. Flies with the “Ken and Barbie” gene have no external genitalia. This is a rare fruit fly indeed. While the human sperm cell is the smallest in the body—it’s only a 500th of an inch long—and a blue whale has sperm only a 5,000th of an inch longer than that—most male fruit flies are real men. One species has sperm that is 2.3 inches in length—the longest in nature—and its testicles make up a whopping 11 percent of its body weight. That’s proportionately larger than our heads. Fruit flies were the first animals in space and are still used by NASA today. They’ve come a long way since their four-legged ancestors of the Middle Ages.

IN LUOYANG CITY IN CENTRAL CHINA THE LOCAL AUTHORITY IS BUYING DEAD FLIES OFF RESIDENTS FOR 0.06 CENTS EACH TO PROMOTE PUBLIC HYGIENE. THIS IS REMINISCENT OF MAO’S 1955 “FOUR HARMS” CAMPAIGN AGAINST FLIES, RATS, MOSQUITOES, AND SPARROWS. IT WAS STOPPED WHEN THE COLLAPSE IN THE SPARROW POPULATION LED TO AN EXPLOSION OF CROP-EATING INSECTS.

MOPMOUTH

Flies “blow” digestive juices on to the surface of their food through the pores on their pseudotrachea. Once the food has dissolved these pores switch to suck mode.

Fossa

Girl becomes boy becomes girl...

The fossa (Cryptoprocta ferox) is only found on Madagascar, where it is the top land carnivore. It’s the size of a spaniel, looks like a cat, but is distantly related to the mongoose. Imagine a cross between a puma and a giant otter that leaps through the branches like a squirrel and you’re close. Its name is a Malagasy word, pronounced “FOO-sa.”

Among many odd things about fossa, one remains completely unexplained and unique. The young females start to grow a penis. Actually, it’s a big clitoris, but it has a bone in it and is covered in the same vicious-looking backward-facing spines as the male appendage. They leak the bright orange discharge of a sexually mature adult male and develop genital bumps that look like testes. Odder still, when they reach maturity at four years old, all this stops and the clitoris shrinks back to normal size.

Quite why the young fossa females want to look like males baffles zoologists. It isn’t accompanied by a surge in male hormones, or aggression, as in hyenas. Maybe it’s just to keep the boys away until they are ready to mate.

A brief examination of their mating habits tends to confirm this. A female in heat will climb to the top of a tree, while at its foot a pack of males gather, making threatening calls and getting into ferocious fights. The female will mate with several males over the course of a week, before another female climbs the tree to take her place. Each copulation lasts up to three hours, punctuated by licking, biting, and yowling as they somehow manage to stay in the branches. The spiny male penis locks them rear to rear, like dogs.

THE FOSSA’S LATIN NAME, CRYPTOPROCTA FEROX, MEANS “FEROCIOUS HIDDEN ANUS”—BECAUSE A POUCH COVERS THE ANUS AND CONTAINS GLANDS THAT IT USES TO MARK ITS TERRITORY.

Fossa were first described in 1833, but haven’t been studied in depth until recently. Madagascar—which is three times the size of the British Isles—separated from the mainland of Africa more than 165 million years ago, and four-fifths of its plants and animals are found there and nowhere else.

Genetic evidence suggests that the eight Malagasy carnivores are all descended from a single species of mongoose that blew in from Africa thirty million years ago. That makes fossa a direct relative of the common ancestor of cats and dogs, which is certainly how they look.

THE DOG-CAT-MONGOOSE THAT LIVES IN A TREE

They are ferocious hunters, and although they don’t actually attack cattle they will take on large female lemurs, consuming everything: fur, bones, and claws. They will also kill snakes, rodents, fish, and birds. Their biggest threat, predictably, is the human destruction of their environment. Since their arrival a mere fifteen hundred years ago, humans have cleared 95 percent of the forests that covered the island.

Madagascan people have a deep fear of fossa, partly owing to the folk memories of a recently extinct fossa relative that was the size of a tiger. Malagasy parents scare their children with tales of them stealing babies or killing all the chickens in a coop with their terrible flatulence.

Zoologists estimate there are twenty-five hundred fossa left, but can’t be certain. They are masters of concealment: some researchers who have studied lemurs for years have never seen a fossa.

Fox

Clever not cruel

The red fox (Vulpes vulpes) is easily the most widespread and abundant wild carnivore on earth. Foxes are astonishingly adaptable and are found almost everywhere in the world, from deserts to the Arctic Circle. But unlike many of its close relatives, including the wolf, the fox is in no danger of being persecuted out of existence: it is the ultimate opportunist and has learned to live alongside humans, without sacrificing any of its feral integrity.

Despite this, the number of urban foxes isn’t increasing exponentially; in most Western cities the population reached its maximum supportable size years ago, and the count of surviving cubs each year is almost identical to the number of deaths. The fox population explosion, like almost everything people think they know about urban foxes, is an urban myth. Even the term itself is inaccurate: “urban” foxes are mostly suburban—they don’t like city centers but prefer areas of low-density, semidetached housing with big gardens, which is why Britain has so many (North American suburbs have raccoons instead).

Urban foxes are just as healthy as country foxes; the town is, if any-thing, a better environment for them than the countryside. They don’t live mainly by scavenging from bins. Foxes will eat literally almost anything: it’s what makes them so successful. Their regular diet includes earthworms, insects, moth larvae, pigeons, rodents, beetles, and plenty of fruits and vegetables. In the autumn, they can practically live on apples, blackberries, and rosehips.

IN JAPAN, FOXES ARE SACRED TO THE SHINTO RELIGION AND “FOX POSSESSION” IS A RECOGNIZED CLINICAL CONDITION. SYMPTOMS INCLUDE A CRAVING FOR RICE AND AN INABILITY TO MAKE EYE CONTACT.

They don’t hunt in packs or kill cats. Foxes live in small family groups, but always hunt alone. They would never attack a domestic cat or dog unless cornered (although they’ve been known to try their luck with swans). Nor do they massacre chickens for fun. Foxes are cache hunters: they will take as many animals as they can, and then bury the carcasses one by one in a larder for later. The reason they leave dead chickens behind in the coop is that they are disturbed on one of their many trips to and from the larder.

Most of the nuisance caused by foxes is far outweighed by their indispensable role as rodent killers. Even the deeply annoying habit of digging up lawns and sports fields is not entirely their fault, as they mistake the smell of blood-and-bone fertilizer on the grass for dead meat, and try to uncover a non-existent corpse. On the other hand, don’t encourage them to nest under your house. At night, the noise of the cubs screaming as they fight and play is indescribable, almost as bad as the smell of carrion, urine, and feces (the latter will be cheerfully deposited as a mark on any shoes or children’s toys you leave outside). They also enjoy chewing through electrical and phone wires and gas and water pipes.

MOUSE DIVING

Urban foxes can easily become tame, even allowing themselves to be fed from the hand and stroked like a pet. This latent tameness was selectively bred in a famous Russian experiment begun in 1959. Within twenty years, the foxes had lost all fear of humans, wagged their tails, and developed floppy ears and black and white fur: they had become, in effect, dogs.

Frog

Toxic paradox

In fairy tales, frogs are ugly but kind; in real life, they are breathtakingly lovely and deadly dangerous. Such is true, at least, of the brilliantly colored tree frogs of South America. Their neon reds, shocking oranges, acid greens, purples, and blues cover the entire visible spectrum, and their eyes are like precious stones.

The world’s deadliest frog is the golden poison dart frog, Phyllobates terribilis. Sometimes mint green, sometimes Kodak yellow, it is no larger than a bottle cap but contains enough toxins to kill twenty thousand mice or ten men. An amount of its poison weighing less than three grains of salt is sufficient to kill a person and even just to hold one in your hand can be lethal. Poison dart frogs are so called because tribes-men use their venom to tip the missiles of their blowpipes. Captain James Cochrane first discovered this in 1823. He also found out how they extracted the poison: skewering the frog so painfully that it sweated it out. The second most poisonous frog in the world is the black-legged dart frog (Phyllobates bicolor) of Colombia. It is bright orange or yellow with navy blue legs. The locals make this one sweat by heating it over a flame.

As a general rule, the more beautiful the frog, the more dangerous it is. This is called aposematism, from the Greek for “warning sign.” The tiny, red-and-white-striped Ecuadorean tree frog, Epipedobates tricolor, seems to be impersonating a barber’s pole. Comical? Certainly not: it will kill you. Other species aren’t dangerous but have evolved to look as if they are. The red-eyed tree frog of Costa Rica is green with blue-and-yellow-striped sides, orange toes, and liquid scarlet eyes. It has a call that sounds like a baby rattlesnake but it is completely harmless. This is called Batesian mimicry after Henry Walter Bates (1825–1892), who spent seven years in the Amazon with Alfred Russel Wallace and found eight thousand creatures new to science.

FROGGY GOES A-COURTIN’

This hug of love (the “amplexus”) lasts until eggs emerge for him to spray with sperm.

Some males grow sticky “nuptial pads” to lock themselves to the female.

TO VOMIT, SOME FROG SPECIES COUGH UP THEIR WHOLE STOMACH AND THEN CAREFULLY RINSE IT OUT WITH THEIR RIGHT FORELEG BEFORE PUSHING IT BACK INSIDE.

Trinidad’s paradoxical frog (Pseudis paradoxa) is so called because its tadpoles are three times larger than the adult, but frogs and paradoxes go hand in hand. There are more than five thousand known species and new ones turn up all the time—a hundred in Sri Lanka in 2002 alone. But they’re also dying out at an alarming rate: a third of all frogs are at risk, because frogs breathe through their skin. Though their toxins can occasionally be dangerous to us, the poisons that humans leave lying around are far deadlier to them. This may be a tragedy for both of us. Frog toxins are alkaloids—like cocaine, nicotine, codeine, caffeine, and quinine—and scientists are finding that these beautiful paradoxes are living medicine chests, whose deadly poisons can be transformed into drugs that may cure everything from cancer to Alzheimer’s disease. Epipedobates tricolor yields a painkiller two hundred times more powerful than morphine; Phyllobates terribilis provides another six hundred times as powerful. Both are nonaddictive, with no side effects. Inside other frogs may be muscle relaxants and heart stimulants, and cures for strokes, bacterial infections, and depression. There is a prince in there, after all.

Occasionally a lustful male will attach himself to an old boot or dead fish by mistake.

Giant Tortoise

Large slow larder

In 2006 Adwaitya, the Aldabra giant tortoise (Geochelone gigantes), personal pet of Clive of India, died in Kolkata zoo, aged 255. He was, as far as we know, the planet’s oldest animal inhabitant, and it is astonishing to imagine a life that began before Mozart and the French Revolution ending with an announcement on CNN. Tortoise longevity is driven by a slow reproductive hit rate. Giant tortoises are big, cold-blooded herbivores, with a sluggish metabolism. It takes them at least thirty years to reach sexual maturity and although, as adults, they have few natural predators, their young are not so lucky. Even the isolation of an island is no protection: only one egg in ten makes it to adolescence. So, a long life means a much better chance of passing on the genes.

GIANT TORTOISE OIL WAS CONSIDERED SO DELICIOUS THAT IT WAS THE ONLY WAY OF MAKING THE FLESH OF THE DODO–CALLED THE “DISGUSTING BIRD” BY THE DUTCH–PALATABLE.

The origins of giant tortoises stretch back fifty million years, to the time when the first turtles hauled themselves onto the land. They were able to exploit the niches left behind by large plant-eating dinosaurs and, predictably, started to grow large. One giant tortoise, Colossochelys atlas, was the size of a small car and spread across the globe, even colonizing Antarctica. But the combination of a cooling climate and human ingenuity condemned them (the shell is an effective barrier to teeth and claws, but becomes an all-in-one cooking pot on a fire). By 1750, when Adwaitya emerged blinking from his shell, there were no continental giant tortoises left, but 250 species basking happily on their predator-free islands. Today, there are only twelve species, all but one of them endangered.

Giant tortoises’ heads gradually grew too big to be with-drawn into their shells—they had survived for so long without attack that even this protection deserted them. They also suffered the misfortune of tasting delicious. Although Darwin—whose theories of natural selection owed so much to the Galápagos species—thought them “indifferent” eating, most early accounts were ecstatic. One giant tortoise would feed several men, and both its meat and its fat were perfectly digestible, the liver was a peerless feast, and the bones were rich with gorgeous marrow. Then there were the eggs: the best eggs anyone had ever eaten. Even more useful to sailors, the tortoises could be taken alive onboard ship and survive for at least six months without food or water. Stacked helplessly on their backs, they could be killed and eaten as and when necessary. Better still, because they sucked up gallons of water at a time and kept it in a special bladder, a carefully butchered tortoise was also a fountain of cool, perfectly drinkable water.

Unsurprisingly, it took three hundred years after its first discovery for the giant tortoise to receive a scientific name: the specimens were all eaten before they got back to the scientists. Worse still, large-scale commercial whaling in the nineteenth century was only made possible because the giant tortoises enabled ships to stay at sea for weeks at a time. One ship’s log records “turpining” parties taking fourteen tons of live tortoises onboard one ship in four days.

If there is a glimmer of hope it concerns Adwaitya’s descendants. In 1875, the government of Mauritius, inspired by Albert Günther of the British Museum, declared Geochelone gigantes the world’s first protected species. There are now 152,000 Aldabras—90 percent of the world’s total giant tortoise population—happily isolated from their only serious threat: us.

Gibbon

The talking ape

One of the odd things about the great apes—our closest primate relatives like the chimpanzee and the gorilla—is that their vocal communication is relatively unsophisticated compared to our own.

Not so the thirteen species of gibbons that live in the tropical forests of Southeast Asia. Gibbons aren’t monkeys—they don’t have tails or cheek pouches—but “lesser apes,” and their calls are some of the most beautiful and idiosyncratic sounds made by any animal. Gibbons use these calls to communicate precise messages, assembling elements of each call into a string that has a meaning understood by other gibbons in their family group, who use a similar sequence in return. Linguists call this syntax—the linking of sounds in a particular way to create meaning—and it is the basis of all language.

NO ONE KNOWS HOW THE GIBBON OT ITS NAME. THE FRENCH NATURALIST BUFFON COINED IT, MAYBE AS A VERSION OF “GIBB,” THE OLD NAME FOR CAT, OR IN HONOR OF HIS FRIEND EDWARD GIBBON, THE HISTORIAN.

The development of this language may be linked to the fact that gibbons—unlike most other monkeys and apes—are monogamous. Like songbirds, gibbons sing to attract and keep a mate and to mark their territory, particularly their favorite fruit trees. To snag the best female to breed with, a male gibbon has to work on his singing. For females, the better the singer, the better the genes, and the more regular the supply of fruit.

Couples sing to each other every morning in fabulously complex duets. Males sing before dawn, sometimes while still in bed, which for a gibbon means sitting high up in the branches, with their arms hugging their knees and their heads tucked into their laps. Females are much more active and dramatic, breaking branches, leaping, and climaxing with a sequence known as the great call. Males who have a mate sing more regularly when there are rogue males sniffing around, as you’d expect.

Most family groups comprise a male and female living with three or four offspring, some of whom don’t leave home until they are ten years old. Because of their energy-poor diet—fruit, leaves, and the occasional insect—families spend half their time just hanging around grooming one another. The female rules the roost at home; the males are right at the bottom of the hierarchy, even below the offspring. In some species the male takes over child care once the young are weaned, teaching them how to swing.

Gibbons are built to swing. Their arms are longer than their legs and bodies combined, and strong enough to propel them at speeds of 35 mph and across fifty-foot gaps between trees. Their wrist bones are separated by soft pads that allow movement in all directions. This enables them to swing and change direction without having to turn their bodies—saving energy and giving them the breathtaking agility for which they’re best known. On the rare occasions they walk on the ground, gibbons are bipedal, which has led researchers to propose that walking on two feet might originally have developed as an unforeseen by-product of arm-swinging in the canopy.

In Thai mythology, gibbons are the reincarnated souls of lost lovers. In one story, a woman searching for her murdered husband wanders the forests to this day repeating the gibbon’s plaintive song, “Pau! Pau! ” (Thai for “husband”).

Giraffe

Big head, bad smell

The ability to reach the leaves at the very top of trees seems reason enough to grow a long neck, but a giraffe’s neck is about more than just food. Male giraffes use their necks as weapons and as signs of their virility. There’s nothing cute about “necking” between male giraffes; they lock them together like arm wrestlers or swing their heads like medieval maces, with a terrifying force that can topple or kill their opponents with a single blow (a giraffe’s skull weighs more than a full-size boxer’s punching bag and sports up to five skin-covered horns called ossicones). Unlike the female’s, the male giraffe’s neck and skull continue to grow thicker throughout its life. The bigger the neck, the more victories, and the greater number of willing females that come flocking. To counterbalance the weight of these heavy-duty sex toys, the giraffe’s neck has evolved with one more vertebra than other mammals, at the point where it joins the chest.

The other key weapon in a male giraffe’s lady-killing armory is his odor: downwind you can smell one from more than eight hundred feet away. Early explorers compared their scent to “a hive of heather honey in September,” but the key chemical constituent is indole, the nitrogen compound that gives our feces their characteristic smell. As well as driving females wild, giraffe pong has a practical function, acting as a built-in parasite repel-lent and killing many of the microbes and fungal organisms that graze on a giraffe’s skin. Giraffes even secrete the active ingredient in creosote to kill bloodsucking ticks. As far as they are concerned, smelling bad means you are clean and healthy.

THE ROMANS EXHIBITED GIRAFFES IN THEIR AMPHITHEATERS AS “CAMELOPARDS,” ASSUMING THEY WERE A CROSS BETWEEN CAMELS AND LEOPARDS.

Most of a giraffe’s life is spent either eating or chewing the cud. Their favorite meal is the acacia tree, which is so thorny that most other animals leave it alone. The top joint of their neck allows them to raise their heads vertically in line with the neck and browse for the young thornless leaves at the very top. Amazingly, the trees have learned to fight back by releasing a chemical that turns their leaves bitter. They also release a wind-borne “warning burst” to alert surrounding trees to do the same. Giraffes, in turn, always try to approach acacias upwind.

Next to the neck, the other essential device is the tongue, which can extend up to twenty inches, long enough to clean their ears. A grasping tool with the same level of dexterity as three human fingers, a giraffe’s tongue is used so often that it has taken on a blue-black color to reduce the risk of sunburn.

MORE THAN JUST A LONG NECK

Breathes often to move 5 pints of air up and down.

Giraffes need less water than camels, and as acacia leaves are 70 percent water, they rarely need to drink. This is good news, because their awkward splayed pose at a waterhole leaves them vulnerable to lions and crocodiles. The only time they kneel is to sleep, laying their head on the ground for ten minutes each day and, even then, keeping half their brain awake.

Giraffes are often hunted for their tail tuft, which, at more than three feet, is among the longest hair found on any mammal. It is used for bracelets and as an unofficial currency in Sudan and Uganda.

Goat

The farmer’s friend

Far from being a poor relation of sheep and cattle, the goat (Capra hircus) was the first herbivore to be domesticated, ten thousand years ago in the mountains of Iran. Without goats, agriculture might never have taken off. The bezoar or wild goat (Capra aegagrus), ancestor of all domestic breeds, seduced the Neolithic nomads with its hardiness, its herdability, and its weed-busting diet. Goats, then as now, much prefer thistles, brambles, and twigs to plain grass (a grass-fed goat suffers badly from worms). It was an unbeatable combination, and as the first farmers radiated outward from the Middle East, the goats followed as a kind of all-terrain convenience store, every bit as revolutionary in their time as seed drills or combine harvesters.

THE WORD TRAGEDY COMES FROM ANCIENT GREEK AND MEANS “GOAT-SONG.”

In developing countries, goats are still a very important economic resource. They produce more milk for their size than cows, and some estimates put goat ahead of chicken and pork as the world’s most consumed meat. Even in the United States, goat is now the fastest-growing livestock sector. The meat is healthy, with much less fat and cholesterol and more iron than lamb or beef. Goat’s milk has more protein and calcium, and less lactose than cow’s milk. They also make good pets and are surprisingly fastidious. If another goat’s saliva has touched their food, or if it has even the faintest taint of dirt, they will refuse to eat it.

SPIDERGOAT

Goats can climb trees and near vertical cliffs.

Their hooves have soft inner pads that attach to rock like suction pads and dewclaws that act like ice picks for the descent.

The only downside is the smell. “Goatiness” comes from a trio of fatty acids present in both the milk and the meat. These are also produced as waste products by the ten million or so bacteria that feed in the human armpit, which might explain our squeamish-ness. Female goats in heat, however, find it irresistible.

Goats have a reputation for lust and excess that has a sound basis in fact. A male goat (buck or billy) is ready for action at just four months. As he comes into rut, he begins to smell strongly—this is not helped by a fondness for urinating along his belly and soaking his beard. To really get in the mood, he will lick his penis and then drink the urine of his prospective partners. The nannies (or does) either stand back and watch until they are needed, or mount one another to further inflame his ardor.

IN SUDAN IN 2006, A MAN CAUGHT HAVING SEX WITH HIS NEIGHBOR’S GOAT WAS FORCED TO MARRY IT AND PAY A DOWRY TO ITS FORMER OWNER.

The man–goat relationship can be equally close. Alexander Selkirk, the castaway who was the real-life model for Robinson Crusoe, used to mark the ears of the goats he “enjoyed most” so as to avoid eating them. The ancient Gauls made goat’s milk hair cream. For a thousand years, the sum of human knowledge was recorded on goatskin parchment. Young goat’s leather made soft gloves (hence the expression “handle with kid gloves”), and the hair from their backs gave us cashmere, the fashionable yarn for ladies; its name is an old spelling of Kashmir, the region where the longhaired goats come from. In 2002 a herd of Canadian goats was implanted with a single spider gene. When their milk was skimmed and the protein extracted it made a fiber that was identical to spider silk. It has been patented as BioSteel.

Goats have a much greater mythological resonance than sheep or cattle. The horn of plenty belonged to a goat. Pan and Satan had goat’s legs and horns, and in Hindu mythology aja means both “goat” and the primordial nothingness from which everything came.

Goose

Smart and saucy

Despite having acquired a reputation for stupidity, geese show signs of great sensitivity and intelligence. Many species mate for life and the death of a loved one leads to behavior that is remark-ably similar to our own. They honk mournfully, stop eating, hunch up their feathers—and can remain that way for months. If one is shot down, its partner will return to earth to stand vigil next to its corpse. Reunited couples perform a triumph ceremony—a combination of dance and song that reenacts their courtship. Geese can even be taught to perform simple tasks—there are several nineteenth-century accounts of them turning spits, using their powerful necks like an arm.

The French ornithologist Christian Moullec has taught a group of thirty endangered lesser white-fronted geese (Anser erythropus) a new migratory path. After bonding with them as goslings, he flew a microlight to lead them the one thousand miles between wildlife sanctuaries in Germany and Sweden, a journey they repeated the following year on their own. They are now so well trained that Moullec and his flock regularly appear as the star turn at air shows.

PEOPLE WROTE WITH GOOSE QUILLS UNTIL THE NINETEENTH CENTURY. “PEN” COMES FROM THE LATIN PENNA, OR “FEATHER.” QUINK, THE WORLD’S TOP-SELLING INK, IS ALSO AN OLD NAME FOR THE BRENT GOOSE.

Although farmyard geese rarely fly, the wild birds are amazing long-distance aviators. Six million lesser snow geese (Chen caerulescens caerulescens) travel the four thousand miles from the Arctic to the Gulf of Mexico twice a year. The barheaded goose (Anser indicus) migrates from Central Asia to India over the Himalayas at a height of 29,000 feet. The swirl of air created by flying in V-formation produces more lift and a clearer view for each bird. They lose altitude by whiffling—a spiraling nosedive, which sometimes leaves them flying upside down.

THE CHIMNEY SWEEP’S GOOSE

Rope is tied around the neck and the goose is pushed down the chimney. The complaining goose dislodges tar and soot.

Geese were domesticated about three thou-sand years ago in ancient Egypt from the wild grey-lag goose (lag is an old word for “goose,” so we should really just call them greylags). It had more to do with sex than food. Wild grey-lags were the focus of fertility cults throughout the ancient world and goose fat was considered a powerful aphrodisiac. The famous geese on the Capitoline Hill, who saved Rome from the Gauls in 390 B.C., were being kept as sexual talismans, not guard dogs.

The connection is still alive in the innuendo of the nursery rhyme “Goosey, goosey, gander,” and for centuries goose was slang for a prostitute while gooser meant penis. The verb “to goose” still carries a sexual connotation.

Because no one ever saw a migratory goose mate or lay an egg, for centuries it was thought they hatched from the barnacles washed ashore on driftwood at the same time of year as they arrived from the Arctic. This belief persisted well into the days when scientists were naming species; thus today we have the barnacle goose (Branta leucopsis) and the goose barnacle (Lepas anatifera).

It caused confusion for the Catholic Church, too. Some dioceses allowed the eating of geese on fast days because they were fish, others because they were “not born of the flesh,” and there-fore a kind of vegetable or nut. Pope Innocent III finally banned goose-eating on fast days in 1215.

Gorilla

Going ape

Gorillas are the largest living primates and the most misunderstood. Their name dates to 480 B.C. when the Carthaginian explorer Hanno described an African tribe of “hairy women.” He called them Gorillai and it was this that American missionary Dr. Thomas Savage decided to use to describe the “monkeylike animal remarkable for its size and ferocity” whose skull he’d seen when he visited the Congo in 1847. In the popular imagination, Savage’s gorilla came to personify animals at their most wild and terrifying, a myth that culminated in the 1933 film King Kong.

THE BEAST WAS A TOUGH GUY TOO. HE COULD LICK THE WORLD. BUT WHEN HE SAW BEAUTY, SHE GOT HIM. HE WENT SOFT. HE FORGOT HIS WISDOM AND THE LITTLE FELLAS LICKED HIM.

KING KONG

Real gorillas are shy and peaceful creatures. They are herbivores, eating green plants and bark. To run a 350-pound male gorilla requires a straw bale’s weight in vegetation every day, which is why they have such huge stomachs (to house the large intestinal tract) and heads (to anchor the huge jaw muscles needed for chewing). It also explains their habit of eating their own droppings; as with rabbits, this helps them extract the maximum nutrition and recycle helpful digestive bacteria and enzymes. Also, because leafy plants are low in sodium, gorillas supplement their green diet with tasty mouthfuls of soil.

Both species of gorilla, western (G. gorilla) and eastern (G. beringei), live in the equatorial forests of Africa, where vegetation is both plentiful and fast-growing. This enables them to maintain much smaller ranges than their cousins, the fruit-seeking chimps. The consequence of this is a harem system where a dominant silverback male lives with up to ten females and youngsters. All a single lady gorilla wants is a large, powerful male with a good-quality home range. As a result, silverbacks are much bigger than the females, but sex isn’t at such a premium as among the promiscuous chimps—a silverback’s erect penis is only an inch and a half long. He doesn’t need to compete sexually once he’s got his troop: they do what he says. At least they do until a younger male tries his luck. This is where the scary ape routine derives from: standing tall, drumming chests with cupped hands, yawning to display canine teeth, roaring and charging. Actual fighting is rare; as with humans, loud threats backed up by size usually carry the day.

Despite this, gorillas are the strong, silent members of the ape family. They aren’t as vocal or as flashy with their skills as chimps, but they have better memories and often do things independently rather than simply for a reward. Koko, a female gorilla born at the San Francisco Zoo in 1971, has mastered more than a thousand words in sign language, and seems able to communicate complex emotions like sadness and even make jokes. She describes herself, touchingly, as “fine animal person gorilla.”

FORWARD PLANNING

Gorillas have only recently been observed to use tools–stones as hammers, leaves as napkins, and sticks to gauge the depth of ponds.

It’s hard to know how much of Koko’s personhood derives from the thirty years she has spent being coached (and loved) by developmental psychologist Dr. Penny Patterson. Ironically, it was just this ability to bond with a human that spelled doom for Kong in the film. Given the precarious position of the gorilla population (95,000 western gorillas and only 6,000 of the eastern species), maybe Koko’s willingness to learn and talk in our language will persuade us to rewrite King Kong’s tragic ending and preserve her relatives in the wild, where they are happiest.

Hedgehog

Disappearing lawn urchin

Snuffling in the dark and gorging on insects, the hedgehog hasn’t changed much in fifteen million years. But, in spite of regularly topping the polls as the U.K.’s favorite garden animal, the British hedgehog population is now in freefall. It has halved in the past fifteen years and the current estimate is below a million. If this continues there will be no British hedgehogs left by 2030.

THE FOX KNOWS MANY THINGS; THE HEDGEHOG, ONE BIG THING.

ERASMUS

Half die before they reach their first birthday; only one in one hundred makes it to five, and fifteen thousand are squashed on British roads each year (down from the mid-1990s peak of one hundred thousand). Road carnage combined with the use of powerful insecticides and the destruction of the grassy field margins that hedgehogs like to nest in make it hard to feel optimistic. Even “urban hedge-hogs” aren’t as adept at surviving in cities as foxes. They fall into swimming pools, get puréed by lawn-mowers, or wedge their heads into food containers and starve to death (McDonald’s has now changed the design of its McFlurry cartons to make them hedgehog-proof). Many also die from diarrhea caused by well-meaning humans leaving them bread and milk. The best way to help a hedgehog is not to feed it but to turn it loose in your vegetable patch. A single adult can eat 250 slugs in an evening.

Spines act as shock absorbers–a rolled-up hedgehog can bounce down a flight of steps without any difficulty.

Ironically, because of their “spiny ball” defense, hedgehogs have very few natural predators. Badgers are the only animals with claws strong enough to prize open a rolled hedgehog, although hungry foxes have been known to urinate on them to force them to unroll. Hedgehogs also have an extraordinary immunity to poison. It takes more chloroform to put a hedgehog to sleep than any other animal of comparable size, and they can survive a bite from an adder that would kill a guinea pig in five minutes.

This resistance offers a clue to the strangest of all hedgehog behaviors: “self-anointing,” which involves them contorting themselves to coat their own back with gobs of foaming saliva. Hedgehogs have been observed self-anointing after chewing on the poisonous skin of a toad, thereby creating a toxic mousse for their spines. This makes them even less attractive to predators, but it doesn’t entirely explain why the smell of shoes, cigar butts, furniture polish, creosote, coffee, boiled fish, face cream, and distilled water should also stimulate the same behavior.

The word heyghoge was first recorded in 1450 and this quickly splintered into regional nicknames like highoggs, hedgepigs, hoghogs, and fuzzipeggs. Before that, the Anglo-Saxons had called them igl and the Normans, urchins, after the Latin for hedgehog, ericius. This came from the ancient root gher-, meaning “to bristle” (which also gave us “horror”).

An adult hedgehog bristles with more than five thousand spines. They are hollow hairs, reinforced by keratin, the same substance our nails are made from. They are extremely strong; a hedgehog can be picked up by a single spine without its breaking. Considering the physical barrier, hedgehogs of both sexes are remarkably promiscuous, mating with ten or more partners each season and sometimes several on the same night. It is never face-to-face, despite Aristotle’s confident assertions. The male circles a female for hours, snorting loudly until she spreads her back legs, flattens her spikes, and points her nose upward. Copulation is very brief and noisy and, once sated, the male immediately trundles off, taking no further interest in the female or the rearing of his offspring.

Hoatzin

Half-bird, half-cow

Very few birds live by munching on vegetation. It’s heavy, low in energy, and slow to digest, not the ideal fuel for flying. But the strange hoatzin (Opisthocomus hoazin)—pronounced “watseen”—of the South American river swamps has actually developed a stomach like a cow’s to cope with its diet of leaves.

The hoatzin’s crop is enormous, fifty times larger than its stomach, accounting for almost a third of its total body weight. And unlike most birds, where it is used for storage, the hoatzin’s crop does most of the digestive heavy work. Like the foregut of a cow, it is full of bacteria and enzymes that break down the cellulose in the leaves. An amazing 70 percent of the fiber gets digested, but as with cows, this takes time. Hoatzins take two days to digest a meal, the slowest of any bird.

The downside of eating like a cow is smelling like one, which is why the hoatzin is known as the “stink bird.” The manurelike pong is produced by fermenting fatty acids in the crop and has kept them mostly out of the human food chain, although their eggs are eaten. The intrepid American ornithologist William Beebe cooked and ate a hoatzin in 1909 and declared it “clean and appetizing.” More recently, micro-biologists have studied the crop bacteria because of its ability to neutralize poisons in the toxic foliage the bird eats. Transferred to cows and goats, these might allow them to graze on a wider range of forage, with an enormous increase in yield.

DESPITE BEING RATHER TAME, HOATZIN GET STRESSED BY TOURISTS. COLONIES THAT ARE VISITED REGULARLY PRODUCE DOUBLE THE LEVEL OF STRESS HORMONES AND LAY A THIRD FEWER EGGS.

They are very social birds, living in groups of five to fifty, and are about as large (and clumsy) as chickens. Their weight makes them poor flyers and they spend three-quarters of their time just perching, spreading their feathers to soak up the sun and digesting their toxic breakfast. They look rather prehistoric, with shaggy russet and light brown feathers, a bright blue face, piercing red eyes with large eyelashes, and a spiky head crest. They are noisy, too: continually grunting, wheezing, and hissing.

What is a hoatzin? Taxonomists still can’t agree. Even with genetic analysis they don’t quite fit into any of the existing bird families. For a long time they were classed as game birds (uazin is the Aztec name for “pheasant”), then as cuckoos and more recently as doves. Now, most reference sources list them, aardvarklike, as a single species in their own order, the Opisthocomiformes—“ones with long hair behind,” referring to their large crest.

Their chicks share a feature with the fossil proto-bird, archaeopteryx: the first two “fingers” of the wing form into two claws. If disturbed, chicks as young as three days old will leap into the water and clamber back through the branches to the nest using their claws like small monkeys. It’s unlikely that the claws are a prehistoric survivor; they are just another odd adaptation to life in the swamp, and disappear as the birds grow older.

A BUMPER CROP

Horse

Made in America

The horse, like the dog and the camel, first carved out its evolutionary niche in the North America of fifty million years ago. In those days, it scampered around the rainforest eating fruit, much as its relative the tapir still does today. But as the planet cooled, and the forests were replaced by vast grass-filled plains, the American proto-horses diversified and adapted themselves to the new environment, eventually crossing the Bering land bridge into Asia. All our breeds of domestic horse are a single species, Equus caballus, descended from these American immigrants; only one wild horse, the Mongolian Przewalski’s horse (Equus ferus przewalskii) has survived.

MANY CULTURES STILL EAT HORSE, ESPECIALLY KAZAKHS, WHO EVEN EAT HORSE RECTUM, AND THE FRENCH, WHOSE PREFERENCE ALLEGEDLY DATES TO THE BATTLE OF EYLAU IN 1807, WHEN NAPOLEON’S SURGEONIN-CHIEF ADVISED THE STARVING TROOPS TO EAT DEAD BATTLEFIELD HORSES.

Horses are animals of the steppe, and many of the adaptations that allowed them to thrive in an open landscape of rough grass continue to affect their behavior today. Poor diet requires a large digestive tract, so they grew larger. Because they aren’t ruminants, horses depend on lots of small meals to maintain energy levels, rather than one large feast. They are hind-gut fermenters, absorbing nutrients through their intestines rather than their stomachs, so a change in diet can cause serious problems: over-rich pasture, moldy hay, and unfamiliar or toxic plants can cause colic or even death. Horses are prey animals: the best defense on the steppe is to run faster than your predator. Hence they have the largest eyes of any land mammal, arranged to give them almost 360° vision. Anything unfamiliar (like a plastic bag) triggers the flight response. Also, because endurance is more important to survival than initial speed, horses’ legs became longer and more powerful, but took time and space to reach top speed. Most humans can beat a horse from a standing start over fifty yards.

This might explain why most of our early interaction with horses seems to involve us killing them for meat. The oldest European hominid fossil, five-hundred-thousand-year-old Box-grove Man, was found next to a butchered horse. In their original homeland of North America, the native horse was hunted to extinction by the end of the last ice age. It wasn’t until Cortez and his Spanish troops arrived in 1519 that Native Americans met their first modern horse. They called them “big dogs,” quite reasonably, as they had relied on dogs for transport until then.

ASLEEP ON THEIR FEET

No one can quite agree when we first started riding horses as well as eating them. They were probably domesticated independently many times and in many places, but the earliest known evidence points to the Ukraine around six thousand years ago, which is several hundred years before the oldest known wheel. It was one of the great breakthroughs in human history (and an evolutionary meal ticket for the horse). Suddenly, we could travel huge distances quickly and wage wars of unprecedented scale and savagery.

As well as being useful and nutritious, horses acquired huge symbolic value, and were worshipped all over the ancient world from China and Mongolia to ancient Egypt and Celtic Europe. Their importance in this regard has never waned, even as their role in combat, agriculture, and transport has diminished. In the U.K. and U.S. alone, there are ten million horses ridden for pleasure and profit, creating an income in excess of $120 billion, a figure that outstrips the gross domestic product of most of the world’s poorest nations.

Human

The storytelling ape

What Darwin suspected, our DNA has confirmed: we are remarkably similar to our primate cousins—we share about 97 percent with gorillas, and more than 98 percent with chimps, although the developmental difference those very particular genes makes is clearly evident. (Interestingly we are hairier than chimps, having more follicles, but their hair is thicker and longer.) The physiological differences are small: our hands are able to make two grips that a chimp can’t; from this one modification all our manual dexterity has flowed. Combined with a gradual preference for walking on our hind legs (which still causes us physical difficulties), it’s not impossible to see how freeing our hands also freed our minds. There is strong evidence pointing to language—the greatest of all tools—having evolved as gesture before it became speech. Culture started with our hands as well as our brains.

HUMAN BEINGS, WHO ARE UNIQUE IN HAVING THE ABILITY TO LEARN FROM THE EXPERIENCE OF OTHERS, ARE ALSO REMARKABLE FOR THEIR APPARENT DISINCLINATION TO DO SO.

DOUGLAS ADAMS

WHERE ALL THE TROUBLE STARTED

The human brain is a third larger than a chimpanzee’s. It consumes 25 percent of all our energy to run.

Why did it take us so long after we had grown our large brains and smart hands to start daubing walls, carving objects, and telling stories? No one knows for sure what caused the so-called great leap forward but the astonishing homogeneity of Homo sapiens’s DNA suggests that humans went through an ice-age “bottleneck” around seventy thousand years ago, with our population being reduced to a few thousand individuals. Life must have been tough for a long time, but gradually as these pockets of humans interacted and grew larger, social relationships would have developed, tasks would have been shared, and campfires lit. Among monkeys and primates, a larger social group leads to greater intelligence. Imitation, communication, learning, and problem solving are all products of primate social interactions. Among humans, it seems reasonable to suggest that these interactions selected for language. It’s a self-reinforcing cycle: once it starts, it snowballs.

And where has the great leap taken us? We have jumped free of evolution. If we were to live in tune with the distribution curves that apply to other species, our total population would be fewer than a million. If we used primates as a guide, our communities would each be 150 individuals: large enough for breeding, small enough for there to be no strangers, with little crime or cheating.

But we human primates have used our brains and hands to transform the world, before our DNA could change us. We have swapped biology for history, nature for technology. The fact that you’re reading this book is singularly extraordinary. You have learned a complex language, and can interpret meaning in its written form. But now this very ingenuity is creating its own limits. The animals and plants we have domesticated are so lacking in genetic diversity they are falling prey to new diseases. Globalization means that at any one time half a million people are in the air, and millions more are on the move, their bodies and suitcases full of organisms hungry for fresh habitats. Cities—our greatest invention—are choking the planet’s skies and threatening the delicate balance of climate that makes life possible.

All human cultures tell the same stories—of the man punished for stealing fire, of the flood that sweeps away all we have built. Only stories, and the imagination that feeds them, may be strong enough to save us from the endless ingenuity of our hands.

Hummingbird

Tiny genius

The smallest bird of all is the bee hummingbird (Mellisuga helenae) and it weighs less than a penny. Despite being not much more than feathered wing muscles, the 320 species of humming-bird carry a huge amount of cerebral firepower. Relative to body size, their brains are twice as large as our own and this helps them do a number of things beyond the scope of larger animals.

Like us, they have a precise sense of time. The Rufous hummingbird (Selasphorus rufus) remembers not only where its food is located, but also when it last fed there. It will leave flowers enough time to fill up with nectar before revisiting them. Hummingbirds are also one of only six groups of animals that learn how to communicate vocally, rather than just through instinct. Humans, whales, and bats do this, but among other birds, it is only the parrots and songbirds that learn by imitation. Special structures in the frontal lobes of the brain control vocal learning, and this skill seems to have evolved independently in all three bird groups. For hummingbirds, it is driven by the need to maintain strict territorial control. Their nectar-licking lifestyle requires so much energy that keeping the neighbors away from the food supply is essential to survival. Singing is the most efficient way of doing this.

Their unique ability to feed from flowers while hovering also requires special brain adaptations. They can see much farther into the ultraviolet spectrum than other birds (perhaps to help with flower recognition) and have a large section of brain dedicated to the visual adjustment that allows them to focus, despite the airflow created by having wings that beat up to two hundred times a second. This also creates astonishing physical demands, so as well as being clever, hummingbirds have the largest heart relative to size, and the fastest metabolism, of any animal. In a single minute, their hearts can beat up to twelve hundred times and they may take as many as five hundred breaths.

Their flying technique is closer to a bumblebee’s than to that of other birds, with ball-and-socket shoulder joints allowing their wings to rotate 180 degrees in all directions. As they hover, the wing tips move horizontally, tracing a figure-of-eight pattern rather than up and down, as with most birds. This means they can generate lift on both strokes, enabling them to fly forward, backward, and even upside down. To keep this up, they need to eat at least their own body weight in nectar (for energy) and insects (for protein) every day. That means visiting an average of fifteen hundred flowers. Because this generates so much liquid waste, hummingbirds are continually dripping urine.

THE CRAZE FOR HUMMINGBIRD “SKINS” FOR HATS AND BAGS PEAKED IN THE LATE NINETEENTH CENTURY: ONE LONDON DEALER IMPORTED MORE THAN FOUR HUNDRED THOUSAND IN A SINGLE YEAR. MANY UNRECORDED SPECIES WERE HUNTED TO EXTINCTION UNTIL IT WAS FINALLY MADE ILLEGAL IN 1918.

Their tiny feet are useless on the ground, so they spend three-quarters of the day perching to save energy. At night, some species go into an energy-efficient torpor—a kind of mini-hibernation—where their metabolism plummets and their body temperature almost halves.

Hummingbird feathers come in two basic colors: reddish brown and black. The amazing range of colors we see is caused by granules of melanin and tiny air bubbles in the feathers that refract light to create a metallic sheen. Light must shine on an iridescent feather at the correct angle, or we only see the dull pigment colors.

Hyena

Girls on top

The female spotted hyena (Crocuta crocuta) carries something between its legs that continues to baffle and fascinate biologists: a clitoris that matches the male’s penis in shape, size, and erectness. Its vagina is fused shut, so it uses this one organ to urinate, mate, and give birth. How and why it has evolved may seem hard to fathom, not least because giving birth often results in painful tearing that kills one in ten mothers and often suffocates the first-born cub, whose umbilical cord is too short to negotiate the elongated birth canal. The usual assumption is that testosterone leaks from male siblings in the womb, dousing the females, as sometimes happens to produce “butch” female mice. But there is little evidence for this in spotted hyenas, and all females are similarly endowed.

The key is social organization. Hyenas live in female-dominated societies, where every member in a clan has a precise hierarchical rank, with females being senior to males, and the female rank being inherited through the mother. This matriarchal social structure rivals those of the higher primates in complexity. In hunting terms, it delivers numerous benefits. A clan will chase their prey for miles, if necessary, until the target animal simply gives up. At that point the hyenas tear into its belly and legs, starting to eat it while it is still alive. This requires coordination and planning, but, above all, tremendous aggression. That’s where the testosterone comes in handy. From birth, spotted hyenas are programmed to fight, and a cub will often kill its twin (they are born in pairs) to establish dominance.

LONG-DISTANCE KILLER

Can run at 35 mph for 3 miles.

Spotted hyenas are Africa’s dominant predator, responsible for a quarter of all game animals killed. Lions are their only rivals, and the two species exist in a constant state of war. Both steal food from each other, but contrary to popular belief, lions scavenge more often from hyenas. In many areas, hyena kills are a lion’s main source of food. Hyenas eat fast, and they eat a lot—a third of their own body weight, or the size of a large lamb, in just half an hour. They devour everything: the concentrated hydrochloric acid in their guts digests even the skin and bones, leaving their scat white with calcium.

THE ANCIENT EGYPTIANS TRAPPED HYENAS AS PETS AND FATTENED THEM FOR THE TABLE. IN THE ETHIOPIAN CITY OF HARAR, “HYENA MEN” STILL FEED WILD HYENAS AT DUSK, HOLDING OUT PIECES OF MEAT IN THEIR OWN MOUTHS.

For centuries, hyenas have been feared as corpse-eating grave robbers, sexual perverts, and cowards. This human dislike of hyenas has ancient roots. The earliest hominid remains in northern Europe from seven hundred thousand years ago are usually found close to hyena-gnawed bones and fossilized droppings. Whether as scavengers or as hunters, our species has evolved in close competition with hyenas.

Their eerily human-sounding “laugh” is really a signal of submissiveness to clan superiors. Hyenas also whoop, to communicate over long distances. It’s often the laugh or whoop that alerts other animals to come and poach their kill. At least one study has suggested that human music began with the collective hunting chants our ancestors used to outsing the ancient enemy.

Hyenas aren’t related to dogs: their closest relative is the cat-like civet. All four modern species, including the termite-eating aardwolf, are endangered through habitat loss and persecution by superstitious humans.

Kangaroo

Bouncing desert cow

Imagine what it must have been like being confronted with a kangaroo for the first time. Here’s Captain Cook in 1770: “It was of a light mouse colour and the full size of a greyhound. ...I should have taken it for a wolf or a wild dog but for its walking or running which it jumped like a hare or deer.” So familiar have kangaroos become that we forget just how different they are from other mammals. A jumping dog with the eyes of a deer, the nose of a hare, and the feet of a gerbil. How did it come about?

THE KANGAROO’S REPRODUCTIVE ORGANS ARE WORTH A DETOUR. THE MALE HAS HIS TESTICLES HANGING ABOVE HIS PENIS AND THE FEMALE HAS THREE VAGINAS. IT’S PERFECTLY LOGICAL. ONE IS FOR BIRTH, THE OTHER TWO ARE FOR SEX: THEY CARRY THE SPERM TO THE TWO WOMBS.

Marsupials, or pouched animals, have ploughed their own furrow for 120 million years, but the large kangaroos (macropods, or “big feet”) are a relatively recent development. The earliest fossils are fifteen million years old, from the time Australia’s forests began to recede. Until then, the kangaroos’ ancestors had been nonhopping creatures of the woods—there was even a carnivorous, sabre-toothed version. Kangaroos adapted to become grass-grazing ruminants, the marsupial equivalents of bison and antelopes, and, like their placental counterparts, they grew larger to house a digestive system that could handle a tough, fibrous diet. Both their stomachs and their large intestines are fermenting vats full of bacteria and enzymes but, unlike cows, they produce not the greenhouse gas methane but another carbon-hydrogen compound: acetate, which they can recycle as energy. Kangaroo gut bacteria may yet help save the planet by producing wind-free cows.

BIG FEET, SMALL CARBON FOOTPRINT

Surviving in the hot, dry outback is all about conserving energy. Hopping is not only fast: it uses less energy than any other mode of transport. To avoid the daytime heat, kangaroos feed at night (hence their large eyes) and spend their days lying in the shade and licking their forearms to cool down. Even the remarkable reproductive system helps. Kangaroos, famously, have short pregnancies, with the tiny jelly bean–sized fetus crawling into its mother’s pouch when only a month old. Less well known is the fact that a female kangaroo can store her embryos for many months in one of her two wombs. This not only means she can swiftly replace a joey that dies; she can also time her births to avoid droughts, saving both energy and water.

This rather undermines the view that marsupial reproduction is less advanced than that of placental mammals. The tiny fetus may be underdeveloped but it has what it needs: functioning nostrils to smell the teat, and two strong forelimbs to get it there in less than three minutes. (Incidentally, this is why marsupials never developed an aquatic species like whales or dolphins—no gripping arms: no babies.) Once safely in the pouch, the joey latches on, but is too weak to suck: the teat muscle exercises its own portion control, squirting just the right amount of rich milk into its mouth. The mother cleans the pouch, licking up the waste and thereby recycling a third of the milk she produces. When the fully grown joey is kicked out to make way for a new sibling eight months later, it continues to suckle for several months. Ever mindful of waste, the mother kangaroo’s mammary glands produce full-cream and fat-free milk simultaneously.

Koala

Cuddly bottom-feeder

Several mammals eat their own droppings, or their offspring’s, but only koalas feed them to their young. The mother produces a soup, known as pap, which the four-month-old joeys slurp up, ingesting important microorganisms and preparing their delicate digestive tracts for the adult diet, which consists entirely of eucalyptus leaves.

Most herbivores don’t go near eucalyptus. The leaves are 50 percent water and contain nasty toxins. But the koala’s guts have adapted to process them, and they feed on only thirty of the six hundred eucalyptus species that live in Australia; they can even tell the age of the leaves by their smell. To qualify as lunch they have to be between a year and eighteen months old, as young leaves have almost no nutritional value and older leaves contain poisonous prussic acid. On the plus side, koalas hardly ever have to drink—they get all the moisture they need from the leaves—but eucalyptus is so low in energy that they spend twenty hours a day asleep, like sloths. This might also explain why they have, proportionally, one of the smallest mammalian brains. Brains burn energy. The koala’s occupies only half its cranial cavity, floating in fluid like a prune.

Not even sex distracts them from sleep for long. It’s very straightforward and takes place on a sturdy branch. The male mounts from behind, bites the female’s neck, and manages about forty thrusts of his bifurcated penis in twenty seconds. Once thrusting stops, ejaculation (into both vaginas) lasts for thirty seconds.

This perfunctory attitude might throw some light on the female koala’s enthusiastic, if mysterious, adoption of lesbian behavior when taken into captivity. Romps involving up to five females are commonplace, and outnumber heterosexual encounters by three to one. They also last twice as long. Unfortunately, wild lesbian sex only helps to spread chlamydia, a sexually transmitted bacterial infection that afflicts three-quarters of all female koalas. Also known as “wet bottom,” it makes them smell bad and leaves them sterile.

THE EUCALYPTUS GUT-BUSTER

Wild koalas are now officially listed as “low risk to near-threatened.” Although aboriginal peoples did occasionally eat them, they didn’t hunt them to near extinction as was once claimed: their population at the time Europeans arrived is estimated at ten million. What nearly did them in was the fur trade. Until it was banned in 1927, millions of skins were exported each year. Now, despite their iconic status, the koala population may be as low as one hundred thousand: bush fires and road traffic having taken a heavy toll. The Australian Koala Foundation estimates that 80 percent of their natural territory has been destroyed.

KOALA MEANS “NO WATER” IN THE DHARUK LANGUAGE. THE DHARUK WHO LIVED AROUND SYDNEY AND BOTANY BAY ARE ALL LONG SINCE EXTINCT. BOOMERANG, DINGO, WALLABY, AND COO-EE! ALL COME FROM THE DHARUK.

The koala’s scientific name, Phascolarctos cinereus, means “ash gray pouch-bear,” but koalas aren’t bears; they are marsupials, close relatives of the wombat.

They have fingerprints that are almost indistinguishable from human ones. All primates have ridged fingertips to help them climb, but marsupials split from the lineage of primates 125 million years ago, before koalas had evolved. The fact that two line-ages independently developed the same trait to do the same job is a good example of convergent evolution.

Komodo Dragon

Big and bad-mouthed

Ten feet long and weighing up to 280 pounds, the komodo dragon (Varanus komodoensis) is already the largest living lizard. Now it holds the distinction of being the largest land animal capable of parthenogenesis (Greek for “virgin birth”).

In 2006 two of the three komodos held in U.K. zoos gave birth despite having had no access to a male. They managed this by a process called “selfing.” In komodos, as in birds (but unlike mammals), it is the female who holds two different sex chromosomes: Z for male and W for female. Each of her ZW eggs has a second mini-egg attached to it, containing a full copy of her genetic information. In the absence of sperm, this gets reabsorbed and fertilizes the main egg, producing a set of male (ZZ) fraternal twins.

This may have evolved as a survival strategy. Komodos are excellent swimmers and are only found on a few small islands in the middle of the Indonesian archipelago. A stranded female could populate a new island by mating with her own offspring.

The komodo was first discovered by Western scientists in 1910, despite the many local stories of a fierce dragon that lived in the island forests. In 1926 W. Douglas Burden, a wealthy adventurer, led an expedition to capture a live specimen. He failed, but his account of the trip inspired the Hollywood producer Merian C. Cooper to make the film King Kong in 1933.

KOMODOS SMELL WITH THEIR TONGUES

THERE IS ONLY ONE MAP THAT STATES “HERE BE DRAGONS”–THE TINY COPPER LENOX GLOBE OF 1507. HIC SUNT DRACONES APPEARS OVER THE EASTERN COAST OF ASIA, NOT FAR FROM KOMODO. . . .

Komodos are often called “living dinosaurs,” but unlike birds and crocodiles they aren’t direct descendants. Komodos are monitor lizards, closely related to iguanas and snakes. They are fearsome carnivores, with flat, serrated teeth (more like a shark’s than a reptile’s) and powerful curved claws. Their bite is fatal and their “killer saliva” is legendary—it contains fifteen virulent strains of harmful bacteria—but recent research has confirmed that komodos are also venomous, with powerful toxins being secreted from glands in the mouth.

As the top predator on their islands, their isolation has allowed them to grow huge. They originally evolved to prey on a now extinct breed of pygmy elephant but will cheerfully take down buffalo, deer, goats, or young komodos. To avoid this, the young spend their early life in the treetops, and when joining a communal kill take the precaution of rolling in the prey’s droppings to make themselves as unappetizing as possible to their older colleagues.

Komodos eat once a month, wolfing down three-quarters of their body weight in a single sitting. Afterward, they lie in the warm sun to stimulate digestion and prevent the food rotting in their stomachs. Sex is predictably violent. Males rear up on their hind legs and wrestle to establish dominance and, having succeeded, restrain the female just long enough to insert one of their two penises in her bottom.

They are highly intelligent. Captive komodos recognize their keepers and can perform simple tricks. But keep your shoes on, as Phil Bronstein found out. The newspaper editor and then husband to Sharon Stone had his foot badly mauled by a “tame” komodo at the Los Angeles Zoo in 2001.

Leech

A barometer that bites

There are 650 known species of leech. They are annelids: very close, but more sophisticated, relatives of the earthworm. Although they range in size from tiny to more than eighteen inches in length, all leeches have thirty-four segments, each with its own “brain.” The head segment contains a simple two-lobed structure, while the others have a clump of neurons called a ganglion (Greek for “a swelling”). A single leech survives on a mere 15,000 neurons (honeybees’ brains contain 950,000).

All leeches are carnivores, but very few species suck blood. The most famous is the European medicinal leech, Hirudo medicinalis. They have three muscular jaws, each of which has a row of tiny teeth. These saw into the skin, severing the capillaries beneath. The jaws sit at the center of a powerful sucker that creates a vacuum around the wound, funneling the blood into the leech’s gut. Leeches feed for up to an hour, swelling to between five and ten times their original size and guzzling as much as a tablespoon of blood. When full, they drop off, leaving a Y-shaped puncture wound, rather like the Mercedes badge. They can live for up to six months on a single meal.

LEECH GATHERERS USED TO STAND IN LAKES AND POOLS, WAITING FOR LEECHES TO ATTACH TO THEIR LEGS.

Leech bites do not hurt, but they can bleed for ten hours. This is because leech saliva contains both an anaesthetic and hirudin, an anticoagulant. Without it, the leech would end up resembling a chubby blood sausage.

TEMPEST PROGNOSTICATOR

The machine consists of twelve bottles, each containing rainwater and a leech.

As a storm approaches, the leech ascends to the top of the bottle and rings a bell.

Leeches were probably first used in medicine in India around 1000 B.C. The practice of bloodletting was used in the ancient Aztec, Babylonian, Egyptian, and Greek cultures. Hippocrates taught that it helped restore an imbalance of the four humors—blood, phlegm, black bile, and yellow bile. By the nineteenth century, the use of leeches in medicine was so widespread that France imported more than forty-two million in 1833 alone. By the end of the century they were collected almost to extinction. Today, they have the same protected status as the white rhino.

The use of the leech in surgery is back with a vengeance. They are used in burn units and in plastic surgery for their blood-draining and anticoagulant properties. They can also reduce the painful inflammation of osteoarthritis and bruises. British hospitals buy fifteen thousand farmed leeches every year.

Don’t try to remove an attached leech by burning it or pouring on salt. This will make it regurgitate into the wound, causing infection. Use a fingernail to slide under each of the suckers in turn. If you are unlucky enough to have a leech attached inside your mouth, gargle with vodka.

In 1799 Napoleon’s troops in Sinai drank water contaminated by leeches. These attached themselves to the insides of the soldiers’ noses, mouths, and throats, killing hundreds through suffocation.

Leeches can predict thunderstorms. The change in atmospheric pressure means the water they swim in dissolves less oxygen, encouraging them to move to the surface. George Merryweather’s Tempest Prognosticator, an elaborate leech barometer, was one of the wonders of the Great Exhibition in London in 1851.

Leech neurons have been used to construct an organic computer called the “leech-ulator.” The device asks the neurons to perform simple sums. Unlike silicon processors, the neurons “think” their answer by forming their own connections, one to another.

Lion

Sub-Saharan couch potato

It’s not easy being a male lion. Although they are the only cats to have adopted social organization over solitary predation, it’s not immediately obvious what benefits it brings. Most of their hunting isn’t cooperative: it only becomes so if the pride is desperate and facing starvation. Even when it is, a single lion has to make the kill, and statistically that’s usually a lioness, because they are faster and more agile. At mealtimes, all social cohesion dissolves; it’s every lion for itself, and while the males hog the carcass, fights break out all around: flailing paws, shredded ears, mewling cubs, and lionesses staking their claim by clamping their jaws on the carcass and refusing to budge.

NO SMOOTHEN THE LION.

CZECH ZOO SIGN

Nor does the pride system seem particularly good at protecting the young. Only 10 percent of cubs make it beyond the age of two; those that survive are lucky to get into double figures: a lion’s life expectancy is much lower than that of the antelopes it chases. It’s just not a healthy way to live, combining a high-fat diet with almost no exercise. The short sprints the lions make when hunting, while being absolutely exhausting, are not the sort of sport that doctors recommend for anything, let alone someone suffering from high cholesterol. And then there’s the stress.

If a male lion isn’t avoiding the hoofs of zebras he’s attempting to kill or keeping other lions and hyenas off his dinner, he’s either sleeping or servicing the insatiable demands of one of the pride’s lionesses. When a female lion comes into heat, the male is looking at four days of pretty constant sex—up to fifty times a day. It’s estimated for every cub that survives a year, its parents will have had three thousand intimate encounters. It’s not immediately obvious why: the female may need lots of spiny penis action to stimulate ovulation, as with domestic cats, or she could be just making sure her old man’s up to the job.

LIONS WERE WIDESPREAD IN EUROPE AND ASIA UNTIL RELATIVELY RECENTLY–THE LAST LION WAS KILLED IN THE CAUCASUS IN THE TENTH CENTURY, IN TURKEY IN THE LATE NINETEENTH CENTURY, AND IN IRAN IN 1941. THE LAST THREE HUNDRED WILD ASIATIC LIONS LIVE IN THE GIR FOREST IN GUJARAT, NORTHERN INDIA.

Each pride consists of closely related females, serviced by a small coalition of unrelated males. These coalitions are regularly tested by outsiders, often younger males who are keen, in the heady flush of youth, to have a pride of their own. Just to be sure, a lioness will occasionally sneak off for some illicit action with one of these rogues. This leads to conflict, which among lions can be very nasty, even fatal. It certainly is for the cubs if the new team wins: the first thing they do is kill, and sometimes eat, the departing coalition’s offspring. No wonder most coalitions last less than three years: it’s too much like hard work.

ROAR POWER

Lions can roar but not purr. Unlike in cats, their throat bones aren’t solid—they’re connected by an elastic ligament that allows their larynx to expand and vibrate.

Lions roar to communicate with one another, not to intimidate prey.

Even the lion’s mane—that universal symbol of virility—means something different to a lioness. Sporting a big, dark mane doesn’t make you a breeding hero; in fact, as a fifty-a-day beast, you’re probably history—manes are the leonine equivalent of nostril hair. But the absolute sign of a lion’s having given up trying to cut it as an apex predator or the King of the Jungle is when he turns man-eater. Slow, weak, and always hanging around, we are easy prey: the lion’s equivalent of a night in front of the TV with beer and a pizza.

Lizard

Pleasantly reptilian

When the remains of the giant reptiles of the Mesozoic era were first discovered, Sir Richard Owen dubbed them “dinosaurs,” from the Greek deinos sauros, “terrible lizard.” Encountering crocodilians in the New World, the Spanish called them el lagarto de Indias, “the lizard of the Indies.” This became “alligator” in English. But though there are more than 4,675 species of lizard, dinosaurs and alligators are not among them. Lizards are the reptile equivalent of rodents, found all over the world. They have a “third eye” in the center of their heads beneath the skin; they smell using their tongues, and the cracks in their bottoms go sideways. Some are legless and distinguishable from snakes only by their movable eyelids, which snakes do not have.

AUTOTOMATIC PILOT

Autotomy = “self-cut.” Lizards are able to shed their tails because of a fracture plane across (or between) their tail vertebrae. The muscles contract above it to snap off the tail and then act as sphincters to seal the tail artery.

The shed tail twitches because the tail muscles have evolved to respire longer without oxygen.

The tail grows back around a tube of cartilage, not a bone. Lizards stop growing and reproducing for a month while it regrows.

The biggest group of lizards are skinks. They have tails with special fracture points. If a predator grabs them, their tails snap off and wriggle convulsively for several minutes, distracting the predator and giving the skink time to escape. The legless glass lizards are even more dramatic: their tails shatter like glass if they’re assaulted. Armadillo lizards (Cordylus cataphractus) roll into balls; blue-tongued skinks stick their tongues out; horned lizards squirt blood from their eyes. Australian frilled lizards (Chlamydosaurus kingii) have a pleat of skin around their necks. When they are threatened, this opens out like a golf umbrella, making them seem much larger than they are. The flying dragons (Draco volans) of Southeast Asia leap from trees, gliding to safety on brightly colored parachutes. And lizards also escape by running—though none quite so stylishly as the basilisk, or Jesus Christ lizard (Basiliscus plumifrons), which has large webbed hind feet, enabling it to stand up and walk on water. The fastest lizards are six-lined race runners (Cnemidophorus sexlineatus): at 18 mph they are the fastest reptiles on earth. Only one lizard lives in the sea: the Galápagos marine iguana (Amblyrhynchus cristatus), which dives thirty feet underwater to nibble algae on the rocks. Some lizards are venomous, but, luckily for humans, they secrete poison by chewing and need a good old gnaw to cause anything more than a mild swelling. The heaviest lizard is the 280-pound Komodo dragon; the lightest is a dwarf gecko so tiny it would fit on your fingertip.

Geckos are popular houseguests in hot countries because they eat insects at night. Brook’s half-toed gecko of West Africa (Hemidactylus brookii) even has a transparent belly to advertise to its hosts how many flies it has caught. Geckos can walk vertically up glass and scientists have recently discovered how. Their feet are covered in half a million tiny hairs, each of which splits into hundreds more with diameters less than the wave-length of light. This creates a powerful bond between the electrons in the two surfaces. Half a square inch of adhesive tape based on this principle has already been manufactured. If enough can be made to cover a human hand, you could hang by it from the ceiling. In China, lizard soup is used as medicine for asthma, colds, lungs, and the heart. In Antigua, lizard soup is also said to be good for asthma. Provided the patient isn’t told what’s in it. Apparently, that just makes it worse.

NILE MONITOR LIZARDS CUNNINGLY LAY THEIR EGGS IN TERMITE MOUNDS. THE TERMITES REPAIR THE DAMAGE AROUND THE EGGS AND THE HEAT OF THE MOUND INCUBATES THEM.

Lobster

The swimming locust

The name lobster comes from the Old English loppestre, the product of a collision between the Latin for “locust” (locusta) and loppe, Old English for “spider.” As arthropods, they are closely related to both. The best-known lobsters are the European and the American, but there are about fifty species, including the hunchback locust lobster, the velvet fan lobster, and the musical furry lobster. Lobsters from 140 million years ago were so like today’s that if you ate one for dinner, you wouldn’t notice the difference.

Lobsters are surprisingly fast swimmers: with a flex of their tail they can shoot along at 15 feet per second. Some have been tracked covering distances of more than a hundred miles a year, in search of food and sex. Lobster sex involves a lot of undressing and urination. Like mice, they use their urine to communicate. Their two bladders are handily located in their heads, so urine can be mixed with water and squirted from their gills into the face of a potential mate. Male and female lobsters usually attack each other on sight, but, luckily, male lobsters find the urine of a molting female arousing. Males wait in their rock shelters, urinating out of the doorway. Females approach when ready to molt, and urinate back at them. They have sex in the missionary position: the male props open the female’s sperm pouch with his swimming legs and, after some leg-fanning foreplay, ejaculates gelatinous sperm capsules into her pouch. He protects her until her shell hardens—about two weeks later—and then hostilities resume.

LOBSTERS ARE PEACEFUL, SERIOUS CREATURES, WHO KNOW THE SECRETS OF THE SEA, AND DON’T BARK.

GÉRARD DE NERVAL

To grow, a lobster must shed its shell. Because the food-grinding teeth inside its stomach are part of the exoskeleton, it has to pull out the lining of its throat, stomach, and anus to free itself. Not all lobsters survive this process. It also makes it hard to tell their age. Many of the ones we eat are more than twenty years old, but a big specimen can weigh as much as a Labrador and may have lurked on the ocean floor for more than a century.

ODD-CLAW ETIQUETTE

Fighting lobsters lock crushing claws until one of them submits. Sometimes, they attack each other’s antennae, legs, claws, or eyes. A large crusher claw can exert as much as 1,000 pounds per square inch on something small (like a human finger). To escape, they can jettison a limb using a special muscle at its base but because lobsters’ blood flows through their body cavities, not veins, they will bleed to death unless leaks are sealed quickly. Legs, antennae, and claws can regenerate, but not eyes.

As long as their gills are damp, lobsters can breathe. They will survive for up to a week out of water. French Romantic poet Gérard de Nerval used to take Thibault, his pet lobster, for walks in Paris using a blue ribbon as a leash.

Early New England settlers considered lobsters barely edible. When storms blew them onto the beach, farmers used them for animal feed or fertilizer and served them only as food for prisoners.

Cooked lobsters are red because boiling transforms protein molecules in the shell into shapes that absorb everything except red light, which is reflected. There is no clear evidence about whether lobsters feel pain. Boiling water is probably the quickest method, but there is no absolutely humane way of killing them.

Louse

Intimate informant

Lice are very small wingless insects, related to bugs, aphids, and cicadas. They live as parasites in the fur or feathers of mammals and birds, feeding on blood, dead skin, or feather parts. Almost all animal species support one or two varieties, living on different parts of their body. Notable exceptions are bats, platypuses, and echidnas, which are louse-free.

Humans carry three lice species: on our heads, our clothes, and our pubes. By studying their DNA alongside those of other primates, we’ve learned rather a lot about ourselves. The pubic louse (Pthirus pubis), for example, is very closely related to the gorilla louse (Pthirus gorillae). The DNA shows the two species split more than three million years ago, so our hominid ancestors either occasionally slept with gorillas, or used abandoned gorilla nests as hammocks. Similar analysis of head lice (Pediculus humanus capitis) tells us that we split from chimpanzees five and a half million years ago, and that we caught a second species from the heads of our now extinct cousins, Homo erectus, three million years later. Body lice (P. humanus humanus) live only on clothing and evolved from head lice about seventy thousand years ago, thus telling us when we first started getting dressed.

THE LOUSE CANNON

Adult lice look like tiny crabs, hence their nickname. They have powerful pincers on their front legs, which they use to anchor themselves close to their host’s skin, by grabbing hair or feather barbs. The shape of some bird lice has evolved to fit exactly in between the barbs so they can’t be removed by preening (which is why birds have dust baths).

THERE IS ONLY ONE SPECIES OF LOUSE THAT IS OFFICIALLY CLASSIFIED AS ENDANGERED: THE PYGMY HOG SUCKING LOUSE (HAEMATOPINUS OLIVERI), ATTACHED TO THE DWINDLING PYGMY HOG POPULATION OF THE INDIAN SAVANNAH.

Lice can’t jump, so you need contact to catch them. Some bird lice hitch a ride with a passing fly if their host dies or becomes too crowded. As a means of distribution, this is risky, as they can’t live on the fly. Most lice can only survive for a day or two if separated from their host. One of the least remarked-upon mass extinctions of recent times was that of the passenger pigeon louse, Lipercus extinctus. When the pigeons died out, so did the louse. Similarly, the program to protect and breed Californian condors in captivity inadvertently destroyed the condor-chewing louse (Colpocephalum californici), when the remaining birds were all fumigated.

Sometimes lice do switch species. The dog louse (Heterodoxus spiniger) infests dogs everywhere except Europe, but it evolved in Australia to feed on wallabies and only moved to dingos when they arrived with Indonesian fishermen four thousand years ago.

Some lice are actively harmful: the feces of the human body louse carry typhus and trench fever viruses. Analysis of the lice found on the buried remains of French soldiers who died in Napoleon’s retreat from Moscow confirms that lice killed more of them than the Russians did.

The nits that children catch from one another are the eggs of the head louse, which the louse sticks to the base of the hair using a special cement. It’s so strong that some females end up sticking themselves to a strand of hair and starving to death. They lay six eggs a day. The optimum population is about a hundred lice per head, which takes about a month to build up.

Mite

Invisible lodger

Mites are tiny, eight-legged members of the spider clan but most are too small for us to see. After insects, they are the most diverse group of animals on the planet. We don’t know how many species of mite there are; more than forty-eight thousand have been identified so far, but this is probably only a tenth of the total number. They can live almost anywhere, on land or sea, from the icy, sunless ocean depths to hot springs where the temperature would boil most other organisms. Only bacteria are more adaptable; mites can raise a family in the windpipe of the honeybee, or hitch lifts between flowers on the beak of a hummingbird. A single square foot of forest contains a million mites from more than two hundred different species.

Not that you have to go as far as the woods. As you read this, the follicle mite, Demodex folliculorum, is using its needle-shaped jaws to feast on the oil from the sebaceous glands at the base of your eyelashes. Demodex mites look like chubby toothbrushes, with a long abdomen and four pairs of clawed legs. They burrow into the follicle headfirst and have a digestive system so efficient they don’t produce any waste. When they die, they just dissolve in situ, with no harmful side effects.

IN-YOUR-FACE INCEST

The female follicle mite produces her first litter without mating.

She mates with her new sons a week later to produce twenty-five more eggs.

The new generation, in turn, crawl off at night to find their own follicles.

Our homes are vast continents teeming with independent mite kingdoms: flour mites, cheese mites, furniture mites, prune mites, mold mites, each feeding and reproducing in its own microhabitat. Probably the most infamous is the dust mite (Dermatophagoides pteronyssinus—or “skin-eating feather-stabber”). They don’t feed on humans but on the flakes of skin that fall from our bodies. Considering each of us produces a small flour bag’s worth of skin flakes a year, there’s plenty for them to chew on. The musty smell that hits us when we empty our vacuum cleaner is caused by the digestive enzymes of dust mites: half a teaspoon of dust contains as many as a thousand mites and 250,000 pellets of their droppings. Although these droppings can aggravate asthma, caution is needed: dust mites do an important job ridding our environment of scurf and dander. Also, they are impossible to remove in the long term. Obsessive vacuuming just redistributes them and their eggs around the house and, worse still, sucks up their main predator, the larger Cheyletus mite that helps keep their population stable. Carpet cleaning is an even happier prospect: it creates just the warm, moist conditions in which they thrive (which is why they like our mattresses so much).

DEMODEX MEANS “LARD WORM.” THE NOTORIOUS NINETEENTH-CENTURY BIOLOGIST SIR RICHARD OWEN, BETTER KNOWN FOR INVENTING THE TERM “DINOSAUR,” NAMED IT.

That’s not to undermine the threat posed by mites and their subfamily, the ticks. They carry viruses on their bodies and in their saliva that cause scabies, Lyme disease, dermatitis, and typhus in humans and mange in animals; a single species, Varroa destructor, came close to wiping out the world’s honeybee population. By far the largest number of mite species feed on plants, and their effect on crops can be devastating, causing billions of dollars’ worth of damage each year. But the mites’ diversity may be their Achilles’ heel. Even mites themselves have mites. In 2001 the green mite that had decimated the African cassava crop was arrested by the import of a predatory mite from Brazil, the plant’s original home.

Mole

The all-seeing nose

Moles aren’t blind, but their pinhead eyes can only tell light from dark. What really sets them apart is their noses, which they use for feeling rather than smelling.

The nose of the star-nosed mole (Condylura cristata) is unique. It looks like a pink sea anemone, but is really a twenty-two-fingered, nongrasping hand that the mole uses to form a complete picture of its underground world. With a much higher density of nerve endings than the average clitoris, it uses a similar brain capacity to that used for sight in other mammals, making it more of an eye than a hand.

STARFACE

The star-nosed mole has the most sensitive of all animal appendages. The “tentacles” grow in a completely different way from fingers. At birth, the twenty-two ridges on the snout gradually unfold and rotate forward.

The star-nosed mole holds two other records. It has the fastest reactions of any mammal: locating, identifying, and eating an insect larva in an average of 227 milliseconds, which is less time than it takes to read the word “mole” and three times faster than most of us can brake at a red light. It is also the only mammal to smell underwater, sprouting large air bubbles from its nostrils rather like a child blowing bubblegum.

If a mole goes without a meal for eight hours, it dies. The diet of the European mole (Talpa europaea) consists chiefly of earth-worms: their tunnels are traps for worms to fall into. They need to eat about a hundred each day. By biting their heads to immobilize them, a mole can keep up to five hundred worms alive in underground larders. Moles drink a lot, too, and at least one of their tunnels will come out by a ditch or pond. Contrary to myth, they do not eat plant roots or other vegetable matter.

If short of worms, a mole might dig 150 feet of new tunnels in a day, the equivalent of a human moving four tons (about a thousand shovel loads) every twenty minutes. Moles are not nocturnal—it’s just that we rarely see them. In fact, they work in shifts alternating four hours of frantic digging and eating with four hours of sleep. They are highly territorial and solitary, each animal’s territory covering anything up to four football fields. This solitary life is only relieved for the few hours each spring when they come together to mate, which sometimes happens above ground.

“MOLE” COMES FROM MOULDWARP, OLD ENGLISH FOR “EARTH-THROWER.” THE DIALECT NAME WAS “WOONT,” MOLECATCHERS WERE “WOONTERS,” AND MOLEHILLS WERE “WOONTY-TUMPS.”

For the rest of the year, moles use their forty-four teeth to make sure other individuals keep their distance. This includes the females, who are equipped with another mammalian first: a pair of ovaries-cum-testicles that release eggs in the spring and testosterone in the autumn when they need to defend their ground. There are differences between the sexes. Males are slightly larger and their tunneling behavior is different. Females build an irregular network, whereas males, of course, tunnel in long, straight lines.

Molehills consist of exceptionally fine soil, prized by gardeners as seed compost. In the second half of the nineteenth century, moleskin provided molecatchers with a very good income. It took a hundred skins to make a waistcoat, and by the turn of the century several million British moleskins were being exported to the United States annually.

The British mole population is now estimated at more than thirty-five million. In 2002 the post of Molecatcher Royal was revived with the appointment of Victor Williamson at Sandringham.

Monkey

Social tinker

Anyone who’s taken children to a zoo will know the tractor-beam-like attraction that monkeys exert. A monkey enclosure is like a PG-13 movie—scenes of mild peril with some sexual content. Children like monkeys because they feel a direct connection with them, and they are right: only the apes are closer relatives. It’s interesting that within a few decades of the word “monkey” first being used (1530, although its origin is obscure), we had already begun to use it as an affectionate nickname for children.

Wherever they are found in the world, monkeys live in big groups. Their relatively large brains, and the intelligence they confer, have enabled them to cope with the complex interactions required to keep a social order going. The more we learn about monkey societies, the more they seem like us. It’s obviously going to delight seven-year-old boys to discover that among Angolan black-and-white colobus monkeys (Colobus angolensis), a burp is considered to be a friendly greeting (like many monkeys they’re leaf eaters, so wind is a constant in their lives). Also, the widespread use of grooming to suck up to the dominant male has a denite schoolboy logic to it, although most schoolboys stop short of removing dead skin and lice from the playground bully.

More grown-up human behavior also finds its monkey equivalent. Monkeys plan ahead: gray-cheeked mangabeys (Lophocebus albigena) make decisions based on the weather, remembering the location of particularly good fig trees and waiting for the sun to shine before setting out on fruit-picking expeditions. Vervet monkeys (Chlorocebus aethiops) display a very human attitude to booze. On the Caribbean island of St. Kitts they have learned to hang out near bars, and finish the cocktails people leave behind. The majority are social drinkers who imbibe in moderation with other monkeys. They prefer their alcohol to be diluted with fruit juice, and they never drink before lunch. Others refuse to drink at all, but 5 percent are serious binge drinkers who consume as much hard liquor as they can, make a lot of noise, and start fights, before finally passing out.

Drunkenness is not the only vice we share. An experiment with rhesus macaques (Macaca mulatta) revealed that they would “pay” to look at pictures of the faces and bottoms of high-ranking females by forfeiting their usual reward of a glass of cherry juice. With low-ranking females, however, the researchers had to bribe them with an even larger glass of juice before they’d pay any attention. Some species have even taken the law into their own hands. Pig-tailed macaques (Macaca nemestrina) “elect” senior monkeys to break up fights and keep order. Their authority rarely requires the backup of force, but as soon as the police monkeys are removed, cliques rapidly form and social cohesion breaks down.

THE WHITE UAKARI IS ONE OF THE ODDEST-LOOKING OF ALL MONKEYS. IT LIVES IN THE BRAZILIAN RAIN FOREST WHERE ITS BALD, BRIGHT-RED FACE AND RATHER HUMAN EARS HAVE EARNED IT THE NICKNAME “THE ENGLISHMAN.”

For all the similarities there is a gulf between humans and monkeys that only our imaginations can fill. Macaques, smart as they are, know if we’re imitating them but can’t make the leap and imitate us back. A deep bond remains, nonetheless, and may even be hardwired. A Canadian research team recently found that up to the age of three months, newborn humans respond as positively to the calls of rhesus monkeys as they do to human speech.

Moose

Lippy northern stripper

Moose (Alces alces) are, by a wide margin, the largest living members of the deer family. A bull moose weighs three times as much as a red deer stag. The weight of his antlers alone would exceed the personal baggage allowance on international flights (fifty pounds), and are wide enough for a child to sling a hammock between them. Moose have grown big to cope with the cold: they are found only in the high latitudes of the northern hemisphere. Big is better for keeping warm (a lower surface-area-to-volume ratio helps prevent heat loss), which is why so many ice age mammals grew so large.

MOOSE ANTLER IS THE FASTEST-GROWING ANIMAL TISSUE, SPROUTING AN INCH A DAY. ANTLERS ARE SENSITIVE ENOUGH FOR THE MOOSE TO FEEL A FLY LAND ON THEM.

Moose have a double layer of insulating fur, and long legs for wading through snow; even their newborn calves seem happy in temperatures of -22°F. More troubling is warm weather: they can’t sweat, and fermenting vegetation turns their stomach into a furnace. In winter, temperatures much above 23°F will set them panting or lying flat in the snow to cool down. During the summer they spend a lot of time wading in water for the same reason.

Moose are notoriously difficult to keep in captivity. Unlike most other deer, who can browse happily on twigs or graze grass, they are specialized feeders. An adult moose needs to eat the equivalent of a large straw bale of vegetation every day, chewing the cud like a cow to extract the maximum nutritional value. They eat leaves, bark, and twigs during the autumn and winter for energy, and marsh plants, when they are in season during spring and early summer, for sodium. Commercial feed can’t match this balance, so captive moose tend to die quite quickly. The need for salt explains why you often see them licking roads during the summer. It’s also why moose spend so much time in the water; aquatic plants like water lilies and horsetails are sodium-rich and moose will completely submerge themselves to graze on the bottom of ponds. Reports of them diving are usually exaggerations: they are the wrong shape and size for serious underwater swimming.

The size and shape of a moose makes them bad news in a collision, so Scandinavian car manufacturers test new models using an artificial moose. Swedish ads disparage Japanese cars with the reminder: “There are no moose in Japan.”

What they can do well is strip trees with their large drooping upper lip (they have no upper front teeth)—the name “moose” comes from the old Algonquian word mooswa, meaning “the animal that strips bark off trees.” Their eyes can move independently, enabling them to see behind while still looking forward; and the long nose, full of soft cartilage and muscle, is a hypersensitive food-finder-cum-sex-aid. This nasal succulence wasn’t lost on local Native American tribes. According to the eighteenth-century naturalist Thomas Pennant, the moose’s nose was the “perfect marrow, and esteemed the greatest delicacy in all Canada.”

In Europe moose are called elks, from the Latin alces, and were first described by Julius Caesar in 50 B.C. The elk became extinct in Britain in the Bronze Age but the name lived on and was used to describe any large deer. When English settlers reached America, the commonest deer, Cervus canadensis, reminded them of its British relative, the red deer (Cervus elaphus). As a result, it acquired the name “elk” and the other huge and unfamiliar beast continued with its local name, “moose.”

Mouse

The furry weed

The histories of humans and house mice (Mus musculus) are inseparable. The original Mus had lived happily outdoors in northern India for millions of years but as soon as our hunter-gatherer ancestors started to farm in Mesopotamia ten thousand years ago, the mouse lifestyle was also transformed. Permanent houses and grain stores inadvertently provided reliable food and shelter, and the small, swift, resourceful mouse needed no further encouragement. The very name “mouse” (from Latin mus and Greek mys) ultimately derives from the Sanskrit root mush, which means “mouse” and also “to steal.” Hence wherever we went thereafter—on foot, in carts, or by ship—the little thief kept us company.

As a result, house mice can be found wherever there are settled populations of people (as well as many places where there are none). They live on all the continents; at altitudes as high as 15,600 feet; as far north as the Bering Sea; and as far south as the sub-Antarctic islands. They live in coal mines, meat freezers, underground railway tunnels. This is partly because they can live on almost anything—seeds, roots, insects, larvae, food scraps—and if they need to drink at all, licking dew or condensation is enough. But the real source of their success is that they can rapidly adapt their behavior to suit the environment they find themselves in. Most animals change slowly. Wherever we take them, mice not only survive: they find a way to thrive.

SANSKRIT HAS FORTY WORDS FOR “MOUSE.” MUSHKA IS “LITTLE MOUSE” BUT ALSO MEANS “TESTICLE.” FROM THIS, WE GET “MUSK” (FROM THE SCROTUMLIKE GLAND OF THE MUSK DEER) AND “MUSCLE” (FROM ITS MOUSE/TESTICLELIKE MOVEMENT UNDER THE SKIN).

Their prodigious fertility helps. Mice are sexually mature at four weeks; a single pair of mice can produce five hundred off-spring in a year. It’s a competitive business and female mice are extremely promiscuous. The bigger the penis, the longer and more frequent the copulation; and the higher the volume of ejaculate, the more likely conception is to occur. A quarter of all litters are the product of more than one father, a strategy that not only ensures genetic diversity but also helps to prevent any new male partner eating a female’s offspring, just in case they are his. In extreme cases, she will even reabsorb the fetuses to prevent their being eaten.

Mouse sex is not without its romantic side. Male mice sing complex songs in ultrasound, both to attract mates and during the act itself. Slowed down, they sound disconcertingly like someone playing a swanee whistle. Most murine communication is via urine, which they dab around continually. Age, sex, health, and sexual status are all encoded in a mouse’s urine “signature.” Male scent is used territorially; female scent is to do with breeding, a kind of mousy “girl talk.” It’s one of the reasons mice dislike peppermint—it scrambles their communication network.

What do we get out of the relationship? House mice now constitute 98 percent of all animals used in genetics research. Amazingly, most of these derive from just two breeding strains (C57BL/6 and L/10) sold to a laboratory in 1921 by Massachusetts schoolteacher and “fancy mouse” breeder, Abbie Lathrop. Also, mice are what most carnivorous predators eat most of the time. This is a very good thing: if there weren’t any mice, they would be forced to eat our livestock. Indeed, without the little thief, it is unlikely that the ancient Egyptians would have bothered domesticating cats in the first place.

Naked Mole Rat

A termite with teeth

A strong contender for the planet’s ugliest animal, the naked mole rat looks like a flaccid penis with teeth. It is also one of the least well named, being neither naked, a mole, nor a rat. Cousin to the porcupine and the guinea pig, it is a three-inch-long rodent, which uses its huge incisors to carve out tunnels in the hard desert soil. Although it looks completely bald, it does have whiskers on its face and tail, which act as navigational sensors, and hairy toes that sweep soil behind it like a broom.

They are the only mammals to live in organized colonies, like termites and bees. Only one female breeds, serviced by a harem of three males and supported by as many as three hundred “workers” and “soldiers,” who divide the tunneling, child care, food collection, and defense functions among them. This behavior is called eusocial (eu- meaning “good”) and has evolved in response to the harsh conditions of their home territory in eastern Africa, where a lack of rain and food mean they need to cooperate to survive. A large colony gives them better odds of coming across the sparse underground vegetable tubers that cater to all their food and drink needs. By carefully boring into them, they can keep the tubers growing, providing a sustainable food source for years.

NAKED CHAIN GANG

Naked mole rats form digging gangs with specialized roles in order to shift the loose dirt out of their tunnels.

Naked mole rats (Heterocephalus glaber, the “odd-headed smooth one”) spend almost all their life underground. Their eyes have become so useless that they usually keep them closed. They can also close their lips behind their teeth, to keep their mouths free of soil while digging.

Except for the queen and her harem, digging is what mole rats do. A quarter of their muscle is in the jaw, and a third of their brain is used to process information from their mouths. Colonies contain miles of tunnels; an individual worker can dig half a mile a month when the soil is softened by rain. That’s equivalent to a human digging the twelve miles from the Statue of Liberty to the Bronx. Mole rats are practically cold-blooded: when they’re not digging or eating, they sleep heaped together in communal chambers to keep warm.

NAKED MOLE RATS FEEL NO PAIN. THEY LACK A NEUROTRANSMITTER CHEMICAL KNOWN AS SUBSTANCE P, WHICH MAY BE AN ADAPTATION HELPING THEM COPE WITH THE NEAR POISONOUS LEVELS OF CARBON DIOXIDE IN THEIR STUFFY BURROWS.

As with other mammals, the newborns are suckled by the mother. The queen gives birth to between twenty and thirty pups at a time, but only has twelve nipples—a unique mismatch for a mammal. Pups get their food by waiting patiently and taking turns.

Queen mole rats are fat bullies, nose-shoving the underlings when their work isn’t up to snuff. A combination of work stress and intimidation seems to be enough to suppress the sex hormones in both male and female workers, although the queen supplements this with a special chemical in her urine, the equivalent of bromide in a soldier’s tea. A sterile worker that is removed from a colony becomes sexually active within a week.

A queen and her harem can live for twenty-five years, producing more than a thousand offspring. When she dies, vicious fights break out between the largest remaining females to decide the next queen. Mole rat colonies are like large, in-bred, dysfunctional families. The lack of interbreeding with other colonies means that the workers are propagating some of their own genes by helping to raise a conveyor belt of siblings.

Octopus

Well-armed

To look at, octopuses are about as different from humans as it’s possible to imagine: no body to speak of, just a head sprouting eight arms (it’s very biologically incorrect to call them legs or tentacles). So it’s pleasing to discover that they have larger brains, relative to body weight, than any animal except birds and mammals, and that they get bored easily. If they are kept in environments enriched with natural features, they grow faster, learn faster, and remember more of what they learn than if they are kept in bare tanks. They remember places where they might find food, and where they have already hunted. And although octopuses are mostly solitary, there is evidence that they can communicate and, if kept together, they establish hierarchies and avoid confrontations. For all these reasons, in the U.K. the common octopus enjoys the same legal status in labs as a vertebrate.

What they are not so good at is recognizing the sex of other octopuses (or octopodes, but never octopi: the word is derived from Greek, not Latin). Put two octopuses in a tank and they will start to copulate regardless of sex. Thirty seconds into a male-on-male encounter there’s usually an unembarrassed disentangling, although some of these gay clinches can last for days. In one case, the two males weren’t even from the same species. Despite Japanese artists’ persistent obsession with giant octopuses pleasuring women in eight erogenous zones simultaneously, octopus sex is a polite affair, carried out at arm’s length. One of the male’s eight arms is for mating and it differs from the others by having a groove on its underside and a grasping tip called a ligula, which in some species inates with blood, rather like a mammal’s penis. The arm carefully places a packet of sperm in a corresponding slot in the female’s mantle (the body/head). The ligula then breaks off and remains embedded in the female. The male dies within a few months of mating. Although octopuses can regenerate lost limbs, they can’t grow a new sex arm.

OCTOPUSES ARE GOOD MIMICS. SOME IMITATE OTHER DANGEROUS ANIMALS LIKE SEA SNAKES AND LIONFISH. OTHERS PRETEND TO BE DRIFTING CLUMPS OF ALGAE OR WATER-LOGGED COCONUTS.

THE OCTOPUS ELBOW

Despite having a completely flexible arm, an octopus forms three “joints” to retrieve a piece of food, just like a vertebrate. This is the simplest, most efficient movement.

Two-thirds of octopus neurons are in the arms’ nerve cords. The nerve cord “chooses” where the joints will go; the brain coordinates the movement.

The male blanket octopus takes sexual discretion to a new level. He is forty thousand times smaller than the female and his technique involves tearing off his mating arm, placing it somewhere on her body, and then swimming off to die. Given that this is roughly equivalent to a herring nudging a blue whale, it’s unlikely that she’s even aware of him. Meanwhile his disengaged arm crawls into her gill slit, where it can live for as long as a month, until her eggs are mature. She then retrieves it, tears it open like a packet of sugar, and sprinkles the sperm over her eggs.

Octopuses are as dextrous as they are smart. They can open jars of jam, use stones as tools to open shells, and wield snapped-off jellyfish tentacles as weapons. Some “walk” on two arms, as if they were bipeds. They use their body muscles to squirt themselves forward, reaching speeds of 25 mph. They can even “fly” using this method—squirting themselves right out of the water to escape predators. As octopuses have no skeleton—the only hard part of an octopus is its parrotlike beak—they can squeeze through spaces as small as their eyeballs.

Owl

Dim and deadly

The large, slow-blinking eyes lend the owl’s face an expressive quality most birds lack and this has doubtless contributed to its reputation for wisdom. In fact, an owl is not overburdened with brain. Its eyeballs are almost as large as a human’s, even though its skull (without feathers) is barely the size of a golfball. This doesn’t leave a lot of room for problem solving. Owls look as they do because they are supremely well adapted for the job of catching small prey at night. Their huge pupils capture a lot of light and the eyeball is shaped like a café salt shaker rather than a sphere to allow space for the largest possible retina. The retina itself has many more light-sensitive rods than detail-focusing cones, enabling owls to see when the light level falls to almost nothing. A long-eared owl’s (Asio otus) eyes are so sensitive that it can locate a stationary mouse in light levels equivalent to a football stadium illuminated by a single candle. The downside of such big forward-facing eyes is that owls can’t move them. If they want to change their range of view, they have to swivel their head. If they want to judge an object’s position accurately, they bob their heads around, reading it from slightly different angles.

AVIAN IMAX

Supersized eyeballs provide multimegapixel imaging with very little light. Offset ears complete the picture.

But eyes are only half the story. An owl’s ears are, in contrast, very sensitive. The flat feather dishes on its face help to capture sound waves like a pair of satellite dishes, channeling them to its ears, which are huge vertical slits running down both sides of the skull. Sometimes these are cock-eyed (or, rather, cock-eared) on the head, with one higher than the other, or else the owl can manipulate its ear flaps to create different-sized openings. This allows it to calculate the precise location of its prey by estimating the tiny span of time it takes for the rustling sound of a mouse to get to each of its ears. It is accurate enough for some species to hunt in total darkness.

IN INDIA IT IS COMMON TO CALL A FOOLISH PERSON “AN OWL”–OWLS ARE CONSIDERED BAD OMENS, MESSENGERS OF ILL LUCK, OR SERVANTS OF THE DEAD.

In addition to unusual sight and hearing, owls have evolved a unique system for silent flight. Their bodies and legs are covered with a great number of downy feathers, and even their flight feathers have unzipped, fringed ends to soften the flow of air over them. This makes them look a lot larger than they really are. The long-eared owl has a three-foot wingspan but weighs less than an orange. To hide, it sucks in its feathers and manages a reasonable impression of a branch.

Owls’ necks have fourteen vertebrae (twice as many as mammals) to allow the head to turn through 270 degrees.

For a long time owls were grouped with falcons, but they now have their own order, Strigiformes, from strix, the Greek for “owl” and the root of the word “strident.” The name mimics the owl’s sound, as does “owl” itself—which comes from the Latin ululatio, “a cry of lamentation.” The owl’s cry and nocturnal habits associate it with omens of death and ill-fortune in almost every culture.

Pangolin

Sacred pine cone

The relatively recent advances in molecular analysis that allow us to trace the family tree encoded in an animal’s genes have thrown up numerous surprises, and nowhere more so than with the pangolin or scaly anteater, a strangely beguiling mammal that looks like a pinecone with legs. For a long time it was classified with the anteaters and armadillos, because it looks and acts like them. Yet its genes tell a different story: it is actually a carnivore, brother under its scales to cats, dogs, and bears.

There are seven pangolin species, four in Africa, three in Asia, in their own order, the Pholidota, or “horny-skinned ones.” All but two have prehensile (grasping) tails that enable them to climb trees. They are mostly nocturnal, emerging from their burrows at night to feed on ants and termites. Like the aardvark—to which they are not related—they operate mainly by smell, tearing open the nests with powerful claws and “drinking” the residents in large gulps. The giant pangolin (Manis gigantea) of Africa can extend its tongue sixteen inches. When not in use it is rolled up in a sheath deep in the chest cavity, its powerful muscles anchored at the pelvis. The tongue is covered with incredibly sticky mucus, supplied by a large gland in the chest. They have no teeth but instead grind their food in their stomachs, swallowing small stones and sand, just as birds fill their gizzards.

IN CHINA PANGOLIN ARE KNOWN AS HILL CARP AND THEIR FLESH IS A DELICACY FETCHING MORE THAN $40 A POUND. THE ANIMALS ARE KILLED TO ORDER IN RESTAURANTS, THEIR WARM BLOOD DRUNK AS A TONIC.

Pangolins have a curious walk, slowly ambling on all fours by resting their front knuckles on the ground and curving the claws underneath. When they want to speed up they walk on their hind legs, rolling forward, balanced by their tail. A hungry pangolin can wipe out an insect colony in thirty minutes. They are highly intelligent predators; if a termite nest proves too big to finish off in one go, they will seal it up and return the following day.

“Pangolin” comes from the Malay peng-goling, meaning “something that rolls up.” All species can roll into a ball to defend themselves. Even a mother carrying her baby on her tail will, when faced with danger, simply roll the young one up inside her. They can erect their overlapping scales, made from keratin (like human hair and nails), and shut them like powerful scissors, chopping off anything that pokes between them, including fingers. The scales are, inevitably, a challenge when mating. Pangolins lie side by side, entwining their tails and forelimbs, so the male can slide in to one side of the female’s tail. As for giving birth, happily the scales don’t harden until several days later.

ANT TRAP

Lies on top of ant nest and opens scales.

There is something mysterious about pangolins, beyond their surprising genetic provenance. Among the Lele people of northern Democratic Republic of the Congo, they are the inspiration for a fertility cult: scaly like a fish but able to climb trees; shaped like a lizard but suckling their young; and giving birth, like humans (usually) but few other animals, to just one offspring at a time. Ironically, it is this very strangeness that most threatens their survival, since across Africa and Asia they are eaten as ritual food, and their scales and body parts are used for adornment and traditional medicine.

Parrot

Vivid conversationalist

Parrots are probably the best-known birds in the world. After cats, dogs, and rabbits, budgerigars (which are a kind of parrot) are the world’s most popular pets. Almost all parrots are brightly colored and they have names to match: rainbow lorikeet, purple-crowned lorikeet, red-rumped parrot, blue-crowned hanging parrot, sulphur-crested cockatoo, peach-faced lovebird, blue-and-yellow macaw. The colors in their feathers result from completely different molecules from those of any other colors in nature. Most parrots are green and males and females are almost identical in color, but whereas male Eclectus parrots are bright green with scarlet underwings, the females are bright red with violet-blue breasts. For many years they were thought to be different species. Eclectus parrots are also the only species where the female is more colorful than the male.

PARROTS ARE AN ANCIENT GROUP, WHICH SPLIT OFF FROM THE OTHER BIRD FAMILIES VERY EARLY ON. THE OLDEST PARROT FOSSIL IS 55 MILLION YEARS OLD, FOUND IN WALTON-ON-THE-NAZE IN ESSEX, ENGLAND.

Other unique parrots include two New Zealand varieties: the kea (Nestor notabilis), or mountain parrot, which is large and strong enough to mount the back of a sheep and tear out the fat around its kidneys while it’s still alive, and the nocturnal kakapo (Strigops habroptilus, or “sensitive-eyed owl”), the world’s heaviest parrot and the only one that cannot fly. The world’s smallest parrot, the buff-faced pygmy parrot (Micropsitta pusio), is just over three inches long, and the largest, the hyacinth macaw (Anodorhynchus hyacinthinus), stands more than three feet tall. Most birds can move only one half of their beaks, but parrots can move both. Their beaks are incredibly strong and close with a force of 350 pounds per square inch but they have just 400 taste buds. This is a tiny number compared to people (who have 10,000) or cows, which, for some unknown reason, have about 25,000, but it’s a lot for a bird. Parrots are among the very few birds that show any interest in sweet things. (Hummingbirds also like sweetness, but have only a tenth as many taste buds—between forty and sixty).

THE LOVE BOOM

The male kakapo makes a mating court on top of a mountain, consisting of several carefully prepared bowls connected by a series of tracks.

He emits low-frequency “booms” from them for up to four months to attract a female, losing half his body weight in the process.

Parrots make loud, discordant shrieks, squawks, and screams: very few have anything that could reasonably be described as a song, but the ancient Romans discovered they could speak and taught them to say “Hail Caesar.” At first, talking parrots (imported from India) cost more than human slaves but eventually they became so common that the Romans got bored with listening to them and took to eating them instead.

No one knows how parrots get their remarkable ability to talk. No parrot in the wild has ever been observed to mimic the call of another bird or animal. In captivity, however, they readily copy any commonly heard sound (such as doors slamming or car horns) as well as speech. Women and children are better at teaching them to talk than men, and African greys, the least colorful of parrots, are the best pupils, able to mimic human speech perfectly. With the help of Dr. Irene Pepperberg, Alex, an African grey (Psittacus erithacus) bought in a Chicago pet shop in 1977, spoke more than one hundred words and could count to six. African greys go on adding vocabulary throughout their lives and can live to be eighty years old. In 1800 the German naturalist Alexander von Humboldt encountered an elderly Amazon parrot in South America that could speak forty words of Ature, a language whose human speakers had long since died out.

Pearl Oyster

Nature’s jeweler

You are very unlikely to find a pearl in your plate of restaurant oysters. Despite the confusing use of the name, edible oysters are about as closely related to pearl oysters as humans are to marmosets. Both are bivalves, anchoring themselves to rock in shallow seas and filtering algae from the current, but they are from entirely different orders and only one produces pearls of commercial size and value. Pearl oysters, close cousins to the scallop, live in tropical seas and can grow to the size of a dinner plate.

Another widespread misconception is that pearls are formed when a grain of sand or grit becomes trapped inside the oyster’s shell. If that were true, pearls would be commonplace rather than highly valued rarities. The oysters’ world is full of grit; they inhabit a universe of sand, and they spend their lives constantly ingesting and expelling it, with no trouble. Pearls are triggered by more serious intruders. These might be small bits of debris—pieces of bone, shell, or coral, for instance—but in most cases it is something more purposeful. Oysters are troubled by various parasites, including species of worms, sponges, and mussels, which drill through the mollusk’s shell. This is the kind of major irritation that triggers pearl formation.

Having been invaded, the oyster acts to isolate the parasite inside a “pearl sac.” The whole of the inside of its shell is covered by an organ called the mantle, which secretes mother-of-pearl. Also known as nacre, this is a wonder substance, strong yet flexible and lustrous, made by sandwiching calcium carbonate crystals between layers of an organic secretion similar to keratin. It entombs the enemy alien in successive coatings, and the end result is a pearl. Pearl oysters can manage up to four layers per day but to create a layer of nacre a twentieth of an inch deep takes two years; a finished pearl, fifteen to twenty. That’s why a ton of oysters might yield as few as three pearls, and the chances of them being perfectly spherical are, literally, one in a million. A single oyster might get several goes; in the wild they can live for eighty years.

JEWELER PIERRE CARTIER ACQUIRED HIS FIFTH AVENUE FLAGSHIP STORE IN 1917 FOR $100 PLUS A NATURAL PEARL NECKLACE VALUED AT $1 MILLION ($15 MILLION IN TODAY’S DOLLARS).

The rarity and beauty of pearls led to many theories about their origin: that they were the result of dewdrops falling into the oyster while it sunned itself at dawn; or they were gallstones or crystallized angels’ tears; or came from bolts of lightning. The grain-of-sand idea was first posited in seventeenth-century Italy, while in the nineteenth century marine scientists proposed dead oyster eggs. It wasn’t until the first decade of the twentieth century that French and Japanese researchers identified the pearl sac theory, leading to the first artificially cultured pearls.

MORE LIKE US THAN MOST PEOPLE THINK

A handy reference guide for your next seafood platter.

Most modern pearls are farmed; it is a big global business with an annual turnover of more than $600 million. It is a slow process. Each animal is opened and has a bead of mussel shell and a piece of mantle (cut from a donor oyster) carefully inserted into its gonad. As the mantle fuses with the surrounding tissue, it is stimulated into producing a pearl sac, coating the bead with nacre. Two years later you get something that is indistinguishable from a natural pearl—just don’t scratch it too hard.

Penguin

Black-and-white belly

Two-thirds of all the birds in Antarctica are penguins. The largest is the emperor penguin (Aptenodytes forsteri, meaning “wingless diver”), which can grow to a height of 3′11″, dive 1,700 feet deep, and hold its breath for fifteen minutes. Forty million years ago there was a much larger Antarctic species, Anthropornis nordenskjoeldi, which was 5′ 7″ tall—the same height as Eddie Izzard or Michelle Pfeiffer. Emperor penguins are famous for their dogged dedication as parents. They take it in turns to look after their egg in bitter subzero weather, making epic trips to find food and losing 40 percent of their body weight in the process. Despite this, only 19 percent of emperor penguin chicks survive their first year. This must put a strain on the relationship.

It’s often said that emperor penguins mate for life, but in fact nothing could be further from the truth. While faithful for the breeding season and when the chick is being reared, at other times emperor penguins have much lower rates of fidelity than smaller species. At least 85 percent of emperor penguins cheat on their partners. They’re mostly straight, though, unlike Roy and Silo, two chinstrap penguins at New York’s Central Park Zoo, who hit the news when they built a nest together, rejected any advances from females, and raised an egg. Silo eventually left Roy to pair up with a female named Scrappy and may well be the first documented case of an ex-gay or bisexual penguin.

PENGUINS HAVE MUCH DENSER FEATHERS THAN MOST BIRDS, MORE THAN SEVENTY PER SQUARE INCH, TO KEEP THEM WATERPROOF. THEIR BLACK-AND-WHITE COLORING IS DESIGNED (LIKE FISH) TO BLEND IN WITH THE SEA WHEN LOOKED AT FROM EITHER ABOVE OR BELOW.

By no means do all penguins live on icebergs. Fiord-land crested penguins from New Zealand nest in coastal rain forests; Galápagos penguins, in tropical volcanic caves; fairy penguins, in burrows; and the Humboldt penguins of Chile, in guano, piles of ancient bird droppings. Many penguins spend 75 percent of their lives at sea. Only emperor and Adélie penguins live exclusively in the Antarctic. Adélie penguins (Pygoscelis adeliae) are named after a French explorer, Jules Sébastien César Dumont D’Urville (1790–1842). In 1840 his ship reached an island off the Antarctic ice shelf, which his men named D’Urville Island in his honor. Later, they came across a little, fat penguin with a black coat and a white apron and named it after his wife, Adélie. The Adélie penguin lives in vast communities of up to seven hundred fifty thousand birds. Like other penguins, they have a maneuver called a “slender walk,” in which they pin their flippers back when squeezing through crowds. Female Adélie penguins build their nests with stones, a rare commodity in Antarctica and one for which they are willing to pay. When their partner’s back is turned, they trade intimate favors with other single males in return for bigger, better stones—the only known example of bird prostitution. Client males are sometimes so satisfied with the service that females can come back for more stones without offering sex, merely a little light courtship. One particularly flirtatious female managed to acquire sixty-two rocks in this way. The males clearly believe the loss of stones is worth it for the opportunity to father more chicks. Zoologists speculate that the female may be trying to improve the genetic variability of her offspring.

GUANO GUN

Adélie penguins keep their nests and feathers clean when excreting guano by standing on the stony rim of their nests, leaning forward slightly, and squirting. They can generate rectal pressure that is four times that of a human—about 7 psi (the same as a keg of lager). This propels it 16 inches away from the nest wall.

Or she could just be having fun.

Pig

More equal than others

There are about a billion pigs in the world and more than half of them live in China. The Chinese relationship with the pig is a long one: it was one of the places where the wild boar (Sus scrofa) was first domesticated, more than nine thousand years ago, and to the Chinese “meat” still means pork. Pork is now the world’s most popular meat: 85 million tons are consumed annually, a third more than beef or chicken. Traditionally, its popularity has been related to the thick protective coating of fat that made it ideal for curing (the process of salting, drying, or smoking that preserves the meat by preventing the fat from oxidizing). In the last decade, health concerns have led to a halving of the fat content, the extra weight mostly being replaced by water. As well as food, dead pigs are a rich source of medical products such as insulin; their skin makes high-quality leather; and their bristles are used in paintbrushes.

PIG STEM CELLS ARE BEING USED TO RESEARCH HUMAN DISEASES. IN ORDER TO TRACK THEM ONCE INJECTED, CHINESE GENETICISTS HAVE CROSSED A PIG WITH A JELLYFISH TO PRODUCE PIGLETS THAT GLOW FLUORESCENT GREEN IN ULTRAVIOLET LIGHT.

Throughout this long history of usefulness, humans have had an ambiguous relationship with the pig. To be a “pig” implies gluttony, stubbornness, and a lack of attention to personal hygiene. At the same time, we admire them for their intelligence and pluck. They are gregarious, playful animals and, as a result, are harder to herd than sheep or cattle: if a pig can escape, it will. Pigs eat both plants and meat, which makes them invaluable as recyclers of human food waste. But pigs don’t eat “like pigs.” They have a third more taste buds than we do (they don’t like lemon rind or raw onions) and unlike sheep, horses, or humans, rarely overeat. However, their “garbage can” status, which made them the backyard animal of choice for Asian and European peasants, also cemented their reputation as an unclean animal, forbidden for Jews, Muslims, and Seventh Day Adventists.

In terms of cleanliness, pigs are actually very particular. They are the only farm animals that make a separate sleeping den (which they keep spotless) and use a latrine area. They just don’t look clean. They turn the ground more efficiently than any plow, rooting incessantly with their snouts. This, combined with rain, quickly leads to mud. But pigs don’t “sweat like pigs.” Because they have no sweat glands, suffer from sunburn, and carry a thick insulating layer of fat, pigs need a mud wallow to keep them cool and protected.

Pigs are highly intelligent. Like dogs they can be easily house-broken, taught to fetch, and come to heel. Pigs can learn to dance, race, pull carts, and sniff out land mines. They can even be taught to play video games, pushing the joystick with their snouts, something that even chimps struggle to master. In the eighteenth and nineteenth centuries “learned pigs,” dressed in natty waistcoats, amazed audiences with tricks. Pigs have even been put on trial and hanged for murder. Maybe it’s this intelligence that some people find unsettling. When a pig fixes you with its long-lashed, forward-facing eyes and sniffs you with its snout (which is two thousand times more sensitive than a human nose), a connection is made that goes well beyond the food chain.

THE PIG ORGAN

In 1450 the future King Louis XI of France commissioned the abbot of Baigne to put on an entertainment bringing together his two great enthusiasms: music and pigs. The resulting instrument was a huge success—the audience could recognize individual tunes.

Pigeon

Undervalued visionary

Before we dismiss pigeons as “rats with wings,” consider why the rock dove, Columba livia, which originally appeared in Australasia 25 million years ago and which still lives happily on some sea cliffs, made such a complete transition to city life. Why are there so many? Cities are full of artificial cliffs (we call them tall buildings) and people throwing out stale bread and dropping half-eaten kebabs. Unfortunately, food stimulates breeding, with the result that we now have nonstop breeding pigeons, with some females laying six times a year, and raising as many as twelve squabs each.

Rock doves were first domesticated by the ancient Egyptians for food and message-carrying. Urban populations were established by escaped domestic birds and they’ve never looked back. The estimate for the damage caused by pigeon droppings in the United States alone is $1.1 billion. But we shouldn’t overreact: there is little evidence to suggest that pigeons pose a serious health risk to humans. The worst disease associated with them is psittacosis, or parrot fever. New York City, home to one hundred thousand pigeons, records one case per year, and pigeons have proved particularly resistant to the H5N1 avian flu virus.

Pigeon eyes are bifocal: the top half sees at great distances, the bottom sees detail close up.

Rather, we should marvel at their gifts. To stay alive in the wild, a pigeon needs to keep its eyes open for predators. Their position on either side of its head gives it a field of view approaching 340 degrees, and in order to fly at speed it has to process visual information three times faster than a human. If a pigeon watched a feature film, twenty-four frames per second would appear to it like a slide presentation. They would need at least seventy-five frames per second to create the illusion of movement on screen (this is why pigeons seem to leave it until the very last second to fly out of the way of an oncoming car: it appears much less fast to them).

ACCORDING TO THE SEVENTEENTH-CENTURY NATURAL HISTORIAN JOHN AUBREY, THE TRADITIONAL REMEDY FOR THE BITE OF AN ADDER WAS TO APPLY THE “FUNDAMENT OF A PIGEON” TO THE WOUND TO SUCK OUT THE POISON.

The U.S. Navy has tried to exploit their keen-sightedness by training them to spot sailors lost at sea: they can pick out a far-away orange life raft much better than a human. They have also been put to work inspecting drug capsules for defects. Pigeon vision is smart as well as sharp: they can tell the difference between Cubist works by Picasso and Impressionist canvases by Monet and are even able to tell when the Monets are hung upside down. They also navigate with great precision, using a combination of odor trails, the sun’s position, the earth’s magnetic field, and, as they get closer to home, visual landmarks like road systems.

Pigeons mate for life; widowed birds accept new mates very slowly. They are also model parents: the male and female take turns to incubate eggs and care for their young in the nest. Both produce “pigeon milk” in their crops. It isn’t real milk—there is no lactose in it—but looks like cottage cheese and is fed to the chicks for their first ten days. That’s why you don’t see baby pigeons: they grow so quickly that by the time they leave the nest, they are almost the size of an adult.

WHY BOB?

Because a pigeon can’t move its eyes, it thrusts its head forward when walking, to keep it stable and maintain life-preserving visual focus.

Platypus

Electric otter

When George Shaw made the first written description of the platypus (Ornithorhynchus anatinus) in 1799, he first carefully checked the specimen he had been sent from Australia for signs of stitching. Even so, many of his naturalist colleagues continued to believe it was a hoax: a duck’s bill sewn onto the body of a small beaver. It took thirty years for it to be accepted as a mammal—the lack of nipples made it difficult to locate the mammary glands under its stomach fur. But it wasn’t until 1884 that the real bombshell fell. A Scottish embryologist named W. H. Caldwell finally uncovered a platypus nest and revealed the astonishing news that here was a mammal that laid eggs (the Aboriginals had been saying this for years, but no one had listened). The platypus has remained notorious ever since, ridiculed as evolution’s little joke.

A popular nineteenth-century view, still held in some quarters, describes the platypus as a crude early prototype of the mammal, subsequently abandoned. It is true that together with the four species of egg-laying echidnas it sits in the monotreme (“one-holed”) order, the oldest surviving group of mammals. But to disparage it as a primitive halfway house between reptiles and mammals makes no more sense than calling a craftsman who builds wooden furniture from scratch more primitive than someone who puts up flat-pack shelving from IKEA. The platypus is a perfect example of a creature that has, in isolation, adapted itself to exploit a rich habitat. Think of it as Australia’s otter, an opportunistic carnivore, guzzling down freshwater crayfish, shrimp, fish, and tadpoles with little competition. It has kept some of the reptilian features, like egg-laying and a lizardlike way of walking, because there was no pressure to change them. But it has also evolved other new adaptations of astonishing sophistication.

The most ingenious of these is the duck’s bill itself. The platypus is a nocturnal creature, feeding at night and dozing in its burrow or wedging under a rock or tree root by day. Hunting at night underwater poses a challenge, as smell and sight are useless. The platypus’s solution—unique among mammals—is to borrow a trick from fish and turn its nose into an electrical probe. The bill is covered in forty thousand sensors that can pick up the tiniest electrical fields generated by muscle impulses in its prey. In addition, it has sixty thousand motion sensors, allowing it to act as both eye and hand, with mechanical and electrical information combining to create a vivid picture of its dark underwater world.

BILL-BRAINED

Interpreting the flow of information from the bill takes up the largest part of a platypus’s brain.

IN 1943 CHURCHILL ASKED THE AUSTRALIAN PRIME MINISTER TO SEND A LIVE PLATYPUS TO CHEER HIM UP. SADLY, “WINSTON” DIED EN ROUTE BUT CHURCHILL HAD HIM STUFFED AND KEPT HIM ON HIS DESK FOR THE REST OF THE WAR.

It has also come up with its own dual-purpose propulsion system. As with beavers, the tail is used to store fat, but when the platypus swims, it acts as a rudder not a propeller. All the power comes from the large webbed front limbs. On land, these skin flaps fold away so it can use its front claws to burrow. Though as fast as an otter in water, the platypus rivals the mole as a digger of tunnels on land, which is why it earned the name “watermole” among the early settlers. Duck, mole, otter? Perhaps it’s the mark of a true original that it can only be described in terms borrowed from something else.

Porcupine

Raunchy and rhythmic

“Porcupine” literally means “spiny pig,” although they are rodents and not remotely related to either pigs or hedgehogs. There are twenty-five species, split between Old and New Worlds. All are spiny, but some New World species can climb trees and swing from branches using their tails like spider monkeys. In Europe, they are native only to Italy and Greece but have been known in Britain since 1110, when Henry I was given one as a pet.

American porcupines are strict vegetarians and suffer from low salt levels as a result—to compensate, they consume anything human sweat has touched: bags, sneakers, paddles, garden furniture, etc.

The inevitable question that crops up with porcupines concerns their love life. As it turns out, avoiding the spines is the least remarkable detail. Porcupine sex often begins with both male and female walking on their hind legs astride sticks, which they use to stimulate their genitals. Once whipped up into a frenzy they stand belly to belly. With his now erect penis, the male soaks the female from head to toe with urine (streams reaching more than six feet have been recorded) and begins to make a loud squeaking, similar to the love song of mice. The female turns her back on him and arches her tail over her back. There aren’t any quills underneath it and he has no quills on his belly. The actual mating lasts only a minute, but the male porcupine has a secret weapon. As with other rodents, his penis points backward in its sheath, unfolds like a penknife when erect, and has bristly barbs on its tip. But the porcupine also has two pointy “nails” on the underside that aren’t found in any other animal. Whether they are for latching on, or giving added pleasure, we don’t know.

The outcome, after a long gestation, is called a porcupette. Unusually for a rodent, there is only one. It is born with its eyes wide open and a fully developed set of quills, which are ready to use within twenty minutes. Indian porcupines (Hystrix indica) seem quite happy with the setup.

They mate for life, and are the only rodents that copulate even when there is no possibility of conception, a helpful adaptation for the monogamous.

NEVER RUB BOTTOMS WITH A PORCUPINE.

GHANAIAN PROVERB

The scientific name for the Old World porcupines comes from the Greek word for them, Hystrix, while the North American porcupine’s Latin name, Erethizon dorsatum, translates literally as “I have a back that provokes.” Despite Pliny the Elder’s assertions, they can’t fire their quills, but tiny erector muscles in the skin do make them stand up. Then they lunge backward, swiping their tails violently. Even tigers run scared.

There can be more than thirty thousand quills on a single animal, and they grow replacements. The quills are covered in backward-pointing scales. These help the quill to work slowly into flesh, where it can be fatal if it hits a vital organ. To remove a quill, cut off the end sticking out first to equalize air pressure inside the wound.

Native Americans used porcupine quills to create sacred designs. The Arapaho no longer practice the craft because the last of the seven women who fully understood the designs died in the 1930s. To attempt quillwork without the proper ritual knowledge is considered dangerous.

African porcupines are attracted by loud drumming and can be taught to shuffle in time to the beat. Porcupine is still eaten there and in Italy, where they have a reputation for yielding even crispier crackling than pork.

Quoll

The Australian killer pussycat

The five species of quoll are known as “marsupial cats,” although they aren’t remotely related to the felines. They don’t look much like them either: their snouts are longer, more like a mongoose’s or a ferret’s, and they have spotted coats and long bushy tails (their family name Dasyurus means “hairy tail”). But they fill the cat-shaped hole in the marsupial world, surviving as nocturnal, solitary predators with the most powerful bite for their size of any animal except their closest relative, the legendary Tasmanian Devil (Sarcophilus laniarius).

This killer streak even surfaces during sex. The female Northern quolls (Dasyurus hallucatus) all come into season at the same time each winter, leading to a free-for-all, as males try to mate with as many females as possible. Grabbing the female’s neck in razor-sharp jaws, they drag them off for an average mating session of three hours, and sometimes for as long as twenty-four. It takes this long because they don’t produce many sperm and need to ejaculate repeatedly to ensure conception. There’s a lot of screeching and biting, as the females crouch with their eyes closed thinking of the spring, but many get injured, and some are even killed and partially eaten by their mate.

“Just wait till your father gets home. . . .”
Female quolls carry their young dangling underneath them, even when climbing trees. When they are larger, they switch to their mother’s back.

In the case of the Northern quolls, at least, they get their own back. The males often don’t recover from the exertion of the rut. They lose weight, become anemic, their scrotum shrinks, their fur falls out, and they get infested with lice. Within a week or two they die, martyrs to their genes. This reduces competition for food, giving the females and their offspring a better chance of survival, but also avoids the risk of incest the following season.

“Hungry?”

The Northern quoll is the smallest of the five and although it’s not much larger than a guinea pig, it is fearless, taking on rats, snakes, lizards, and pretty much anything that crosses its path. Unfortunately, this includes the poisonous cane toad (see above), which has encroached on its territories, and which it eats before it realizes the danger. The population decline is now so steep that conservationists and local Aboriginal groups in the Northern Territories have transported small groups of Northern quolls to outlying toad-free islands.

THE WORD QUOLL WAS FIRST RECORDED BY CAPTAIN COOK IN 1770. IT COMES FROM DHIGAL IN THE GUUGU YIMIDHIRR LANGUAGE OF NORTHERN QUEENSLAND, WHICH HE TRANSCRIBED AS JE-QUOLL.

All the Australian quoll species are threatened, both by introduced predators and by their own adaptive short-comings. A recent test with the Eastern quoll (Dasyurus viverrinus) demonstrated that it couldn’t tell the difference between the call of a fox and that of a cow. It is now only found on Tasmania and, although it regularly pops out thirty young, only the first six to find a nipple survive.

Even the spotted-tailed or tiger quoll (Dasyurus maculatus), the largest carnivore on mainland Australia, has been added to the endangered list, as its population has shrunk to fewer than a thousand. Its version of the quoll suicide gene is to site its communal dung heap in the middle of bush roads.

In 2001 Michael Archer, director of Sydney’s Australian Museum, suggested that to save quolls from extinction, people ought to take them up as pets: “Instead of canoodling with dogs and cats, cuddle a quoll instead!”

Rabbit

The unstoppable pet-pest

“The introduction of a few rabbits could do little harm and might provide a touch of home, in addition to a spot of hunting.” Rarely has a human prediction proved more wrong. These were the words of Thomas Austin, an English settler in Australia, who released twenty-four rabbits on his farm in 1859. Ten years later, there were so many across Australia that even a cull of two million made no dent in the population. By 1950, when the myxomatosis virus was introduced as a biological control, there were more than one billion Aussie rabbits, the fastest spread of mammals ever recorded. As a result, an eighth of all native Australian mammals and an unquantifiable number of plant species perished, their habitats destroyed by overgrazing and erosion. Myxomatosis worked—the rabbit population was decimated, but the small number that survived have bred a genetic resistance to the disease, so a new, less effective virus (rabbit hemorrhagic disease) was introduced in 1995. The population is currently a hundred million and growing.

What makes the European rabbit (Oryctolagus cuniculus) so successful? Firstly, diet. They will eat most things that grow, and in quantity: a single rabbit can eat enough grass to stuff a decent-sized pillow every day. Secondly, unlike hares and most other rabbit species, they run a communal burrow system that supports a large number of breeding females. And finally, they breed like—well—rabbits. A doe is usually either pregnant, lactating, or both at once; she can produce thirty kits a year and they are all able to reproduce within six months of being born. Males tend to disperse to new colonies, females stay put to breed until the warren gets too crowded. Unless predation or disease intervenes, rabbit populations spiral.

WORLD’S THIRD MOST POPULAR PET

There are more than a hundred breeds of domestic rabbit in every shape, color, and size. All of them are bred from the European wild rabbit.

THE SUMATRAN STRIPED RABBIT (NESOLAGUS NETSCHERI) IS SO RARE AND SHY THAT THERE IS NO WORD FOR IT IN THE LANGUAGE USED WHERE IT LIVES. IT WAS THOUGHT EXTINCT IN THE 1930S, AND HAS ONLY BEEN SEEN THREE TIMES SINCE.

Despite appearances, rabbits aren’t rodents, they are lagomorphs (“hare-shaped”), one of more than fifty species, including hares, pikas, jack-rabbits, and cottontails. Lagomorphs have a special trick: eating their food twice. Whereas a cow chews the cud, they eat their own droppings. Not the dry fibrous spheres we find scattered outside their burrows, but the contents of their large intestine, which look like bunches of shiny green grapes and are full of bacteria, generating essential nutrients, especially B vitamins. Strictly speaking, despite their provenance, these are not feces, but food. They are coated with rubbery mucus to protect them from the digestive process, and rabbits eat them directly from their bottoms.

It wasn’t until the mid–nineteenth century that the resourceful rabbit became a serious agricultural problem in Britain. When they were first introduced by the Normans, rabbits were a valuable farm animal, kept in enclosed warrens (by warreners) for their meat and fur. Poaching rabbits was a high crime carrying draconian punishment. But by the 1820s, not only were landowners enclosing their land with endless miles of hedges (the perfect environment for escaped rabbits), they also unleashed an orgy of shooting, poisoning, and trapping of the foxes, martens, stoats, and birds of prey that had previously controlled rabbit numbers. Ironically, the “spot of hunting” that Thomas Austin fancied on his new Australian farm transformed the rabbits back home from crop to pest. The once exotic rabbit now costs British agriculture £100 million each year. Ironically, rabbit meat sold for the British table is mostly factory-farmed and imported from China, Hungary, and Poland.

Raccoon

Porky New Yorker

You can learn a lot about raccoons from the words for them in other languages. The English “raccoon” is derived from Algonquian Indian arahkoonem: “they rub, scrub, scratch.” In Dakota-Sioux, a raccoon is weekah tegalega, “magic one with painted face.” In Abnaki, it’s asban, “one who lifts up things.” The Delaware Indians called it wtakalinch, “very clever with its fingers.” Spanish colonists adapted the Aztec word mapache (“that which has hands”), although the Aztecs also called it eeyahmahtohn (“the little old lady who knows things”).

Raccoons are the best-known wild animals in North America. They have a black mask over their eyes and a bushy tail with between four and ten black rings. They have five toes on each foot and their front paws are provided with thumbs, thanks to which they can lift latches, unscrew jars, disentangle knots, turn doorknobs, and open refrigerators. Their paw prints look like tiny human baby handprints. Raccoons adapt remarkably easily to the human environment and many of them live happily in New York City. They can live to be sixteen in the countryside but urban raccoons eat a similar diet to teenagers, becoming so dependent on French fries and doughnuts that they can’t survive in the wild.

Fat is a raccoon issue: for some, 50 percent of their body mass is fat. The fattest-ever raccoon was called Bandit; he lived outside Ice Cream World in Walnutport, Pennsylvania, and loved to feast on peanut butter and blueberry slush puppies. Raccoons are rightly called omnivores. They really will eat anything. They tuck into crayfish, apples, mice, eggs, insects, walnuts, frogs, fish, sweetcorn, clams, cherries, turtles, acorns, snakes, and even roadkill. Almost all non-American languages, from German and Finnish to Chinese, Japanese, and Bulgarian, call them “washing bears” because they seem to wash their food before eating it. For a long time, scientists thought this was because they couldn’t produce enough saliva to swallow anything dry. In fact, this is not so. They have plenty of saliva, and they’re not actually washing what they’re about to eat. They do dunk food in water—an odd behavior called “dabbling”—but it appears they’re just sorting out what is edible and not too sharp to ingest. If there’s no water about they will still exhibit similar dabbling behavior, and they’re quite happy to eat food that has dirt on it. In search of food, raccoons are good climbers. They can rotate their back feet through 180° and climb headfirst down trees, but they are equally at home in chimneys, haylofts, and attics.

RACCOON IS A POPULAR DISH IN THE SOUTHERN UNITED STATES, THE CENTERPIECE FOR A TRADITIONAL “COON DINNER.” ONCE THE GAMEY FAT HAS BEEN REMOVED, IT IS EXCELLENT ROASTED WITH A STUFFING OF SWEET POTATO.

HANDSIGHT

Not many animals can safely take on a crayfish in the dark.

Raccoons’ hands are incredibly sensitive and are used more than sight and smell to locate and assess the quality of food.

Raccoon droppings are crumbly, tubular, and flat-ended. DO NOT EAT THEM. DO NOT EVEN TOUCH THEM. They may contain up to 250,000 eggs of Baylisascaris procyonis, a nematode worm that can cause severe illness in humans. If you eat the eggs, the larvae can migrate to other tissues, including the brain and eyes. There is no effective therapy. Raccoons look cute but many of them also carry rabies (of which they show no sign). They have bones in their penises (which people in Texas like to carry around for good luck). Dante Gabriel Rossetti, the Pre-Raphaelite poet, kept a raccoon in his Chelsea menagerie. It inspired no poetry, but did manage to disgrace itself by opening and eating its way through a whole drawerful of his manuscripts.

Rat

Man’s new best friend

Outside the polar ice caps, the only place in the world where you won’t find any brown rats (Rattus norvegicus) is the province of Alberta in Canada. From its home base in Mongolia, the brown rat followed the spread of human cities across the steppes, finally swimming the Volga into western Europe in 1727. From there it traveled the world on ships, scurrying ashore at every port and eventually reaching Alberta’s eastern border in 1942. The Albertans decided to fight and set up a 400-mile-long buffer zone that is still patroled by rat vigilantes. Alberta is cold and human habitation is sparse, so they may just hang on. For the rest of us, the battle was lost before it began. In the United States there are an estimated 150 million brown rats; in the U.K., they now outnumber people.

Here’s the problem. A rat can swim for seventy-two hours nonstop. It can jump down fifty feet without injury. It can squeeze through a half-inch gap, leap three feet, climb vertical surfaces, and walk along ropes. It can survive longer than a camel without water. It will eat anything that’s edible and lots of thing that aren’t (lead sheeting, soft concrete, brick, wood, and aluminum). It reaches sexual maturity at three months. Rats have sex up to twenty times a day, and are extremely promiscuous: an in-heat female can have sex more than five hundred times with a barn-load of different males and produce twelve litters of twenty-two young each year. In short, rats are very, very hard to get rid of.

FIRST CATCH YOUR RAT. . .

Rats are considered a delicacy in Africa and Southeast Asia. Cantonese recipes include crispy fried rat, braised rat with black pepper, salt-roasted rat, and rat kebab.

When catching a rat, it may jump up at you, but it’s not going for your throat: it’s aiming for the daylight above your shoulder.

Which would be fine if we could just grow to love them. That’s the next problem. Brown rats consume about a fifth of the food produced in the world each year. They carry more than seventy extremely infectious and unpleasant diseases: bubonic plague, of course, which has killed a billion, but also cholera, typhus, tuberculosis, Weil’s disease, salmonella, cryptosporidiosis, E. coli, hoof-and-mouth, SARS, and eight species of parasitic worm. A quarter of all electrical cable faults are due to rats’ ever-growing teeth, as are most unexplained domestic fires. Like mice, their communication system involves near constant urination—rats pee on one another to show affection, attraction, dominance, and submission, and on food just to show it’s edible. Oh, and they carry a lively subculture of fleas, mites, and lice everywhere they go, which is everywhere we go. It is very, very hard to love the brown rat.

SOME PEOPLE SAY THAT YOU ARE NEVER MORE THAN SIX FEET AWAY FROM A RAT BUT ACTUALLY I BELIEVE THE DISTANCE IS MORE LIKELY TO BE ABOUT SEVENTY FEET.

TONY STEPHENS, RENTOKIL

Not that there isn’t plenty to admire. They are intelligent and resourceful; they learn fast and have excellent memories. Their sense of smell is of such sensitivity and refinement that it makes you wonder why they waste it all on water sports. They seem to have a sense of fun and an ultrasound giggle that they use when being tickled, during sex, or when a rat they fancy sprays on them. They make very good pets, and despite the evidence to the contrary, spend almost half their lives keeping themselves clean.

But it doesn’t matter what we think. Thanks to our wasteful habits, rats are unbeatable evolutionary winners. Maybe in time the brown rat will itself be driven out, as it drove out the black rat (Rattus rattus), which in the U.K. at least could now apply for endangered species status. But whatever takes its place, you can rest assured that it will only be a bigger, better, smarter rat.

Salamander

How to grow new eyes

The five hundred species of amphibious salamanders come in every shape and size, from the giant Chinese (Andrias davidianus)—which can be six feet long and weigh 70 pounds—to the tiny Thorius, which is the smallest land-living vertebrate at half an inch long, and the smallest animal of any kind with proper eyes.

The axolotl (Ambystoma mexicanum) is the most celebrated. Only found in a single lake in Mexico, at a certain point in their evolution they just stopped developing into adults, and now spend almost their whole life in the water as large tadpoles. Why they took this backward step isn’t clear. It might have been provoked by the land habitat around their lake becoming more hostile, but it doesn’t seem to bother other salamander species that live there. Occasionally, they do grow up into something resembling an adult tiger salamander; this can be artificially stimulated by injecting them with hormones. Ninety-nine percent of the world’s axolotls are now kept in captivity, most of them descended from the six specimens that arrived in French zoologist Auguste Duméril’s Parisian lab in 1863.

AXOLOTL IS THE AZTEC WORD FOR “WATER DOG.” THE BUILDERS OF THE ORIGINAL MEXICO CITIES WERE PAID IN AXOLOTLS: THEY WERE USEFUL AS FOOD AND MEDICINE. IN JAPAN THEY ARE POPULAR PETS, SOLD AS WUPERRUPERS.

THE MOST POWERFUL MUSCLE IN THE WORLD

The giant palm salamander, Bolitoglossa dofleini (“bullet tongue”) whips its tongue out in 7 milliseconds—fifty times quicker than a human blink.

Salamanders are committed homebodies, traveling less than a mile from their birthplace over the course of their lives. This can prove fatal when the temperature changes: huge numbers perish each winter.

One species has beaten this problem. The Siberian salamander (Hynobias keyserlingii) can survive in temperatures as low as –58°F by producing antifreeze chemicals before it hibernates. They can stay frozen for many years—some may even have been slumbering since the last ice age ended ten thousand years ago.

The most persistent myth about salamanders is that they live in fire and can douse flames with secretions from their skin (asbestos was originally called “salamander wool”). No one knows where or why this idea arose, but they do have a dangerous habit of sleeping in damp woodpiles. . . .

Newts are salamanders that return to the water to breed. They are the only vertebrates that can regenerate large parts of themselves, growing new limbs, spinal cords, hearts, jaws, tails, and even new lenses and irises for their eyes.

Newt cells can restart the growth process. As the damaged part heals, the cells reverse their original function and turn back into an undifferentiated lump called a blastema (from the Greek blastos, “bud”) from which the replacement limb or tissue grows. If a blastema is moved to another part of the salamander’s anatomy, the missing bit will start growing there.

How the cells know what to grow isn’t understood, but salamanders are being studied closely to see whether human tissue could be stimulated to regenerate. Also, because malignant tumors seem to grow in a very similar way—injecting cancerous tissue into newts can also cause a new limb to grow—they may hold important clues in the fight against cancer.

Scorpion

Fluorescent assassin

Scorpions were the first predators to crawl out of the sea onto land, and they have evolved very little in the last 430 million years because they are very good at what they do. In their prime, during the oxygen-rich atmosphere of the Carboniferous period, scorpions as big as dogs roamed the land, and in the sea giant water scorpions grew to twice that size. Like their younger arachnid cousins the spiders, scorpions are tough and adaptable, putting up with subzero temperatures and desert heat. They can even survive two days completely submerged in water. They are found on all major land masses except Greenland and Antarctica. For two hundred years, an illegal immigrant colony of yellow-tailed scorpions (Euscorpius flavicaudis) has lived in the harbor wall at Sheerness in Kent.

DIRTY DANCING: SCORPION “FOREPLAY”

Part of this indestructibility is due to their highly efficient metabolism. They eat slowly but for several hours at a time, dissolving their prey with powerful stomach juices, and leaving behind a small ball of indigestible tissue. A single meal can increase their weight by a third, and some species can survive on that for a year, storing their food as glucose in a large liver-like organ. They burn energy at a quarter of the speed of insects and spiders, and very few scorpions ever need to drink. This gives them an advantage as predators but they are also very well equipped when they do need to kill. They have two sets of eyes: one to tell them the time of day or night and a more complex set, with lenses and retinas, that are the most light-sensitive organs of any invertebrate. Using the hairs on their claws they can triangulate the precise position of lunch, picking up vibrations caused by movements as slight as twenty-five millionths of an inch.

A female scorpion gives birth to live young, unusual for an arthropod. Even more extraordinarily, some species are pregnant for longer than humans. They are one of the very few invertebrates to have independently evolved a womb where embryos are fed by teats linked to the mother (rather than by the yolk of an egg). Labor can take days, with up to a hundred offspring scurrying up their mother’s claws to nestle on her back underneath her sting, so nothing can get to them. Nothing that is except the mother, who, if suddenly peckish, may snack on them herself.

ISIDORE OF SEVILLE BELIEVED THAT SCORPIONS WERE FORMED FROM THE DEAD BODIES OF CRABS AND, THOUGH VERY FOND OF THE SMELL OF BASIL, WILL NEVER STING THE PALM OF YOUR HAND.

Despite the widespread myth, scorpions do not go mad and sting themselves to death when a drop of alcohol is placed on them, or when confronted with fire, as they are immune to their own venom. Of the fifteen hundred known species of scorpion, only twenty-five have stings that are dangerous to humans; most are no worse than a bee sting. Scorpion venom can even save lives: protein from the Israeli yellow scorpion’s (Leiurus quinquestriatus) venom has been used to kill brain tumors.

Scorpions are fluorescent under ultraviolet light as a result of special proteins in their exoskeletons. As they can’t see this themselves, no one is quite sure why. It might be to mimic insect-attracting plants, to warn off predators, or even to act as a built-in sunscreen.

Sea Cow

Slow and seductive

The sea cow family, or sirenians, contains the dugong (Dugong dugon) and three species of manatee (Trichechus, after their hairy snouts). As their common name suggests, these large, docile creatures are the only aquatic mammals that live on plants. Although they look like gray tuskless walruses, their closest relatives aren’t cows, walruses, or whales but another large herbivore, the elephant.

Sea cows have a very laid-back life. They paddle around in warm tropical seas, with little competition for food and no natural predators. As a result, they have a very leisurely metabolism. The largest adults weigh more than a ton and spend eight hours a day slowly chomping through six straw bales’ worth of aquatic plants, which take a week or more to digest. Life is slow enough for algae and barnacles to grow on their skin. Some dugongs have been recorded as living into their seventies, and they only manage one calf every three to seven years.

When they aren’t eating or sleeping, sea cows come together regularly to cavort. These sessions of nuzzling, bumping, kissing, and mutual masturbation are often male-on-male, but can involve up to four individuals of either sex and last for several hours. The normally silent manatees make a sequence of distinctive snort-chirps as they cavort, though no one knows how (even if we can guess at why). This pleasure-filled life, combined with the female dugong’s large and elaborate clitoris and pendulous “breasts,” has contributed significantly to the mermaid myth. In the Solomon Islands, “dugong” is the slang term for prostitute.

MANATEES OFTEN CONGREGATE NEAR POWER PLANTS, BECAUSE OF THE WARM WATER. IN RETURN, THEY KEEP THE SURROUNDING CHANNELS CLEAR OF WEEDS.

Dugongs and manatees also have a reputation for stupidity and their brains are, proportionally, small and smooth, roughly the equivalent of our brains shrunk to the size of a plum. In their defense, their brains seem well up to the job and some have even been trained to recognize colors and patterns in return for food.

More significantly, low metabolism and the absence of stress help make them impervious to the diseases that afflict other mammals, propelling them to the forefront of research into cancer and HIV.

This may also explain why they have six neck vertebrae rather than seven. In mammals, the genes that specify the number of vertebrae also control the nervous system and cell growth. Changes in this genetic data can cause cancer, so natural selection has tended to leave them alone. However, in a low-metabolism mammal like a sea cow, the risk of cancer is greatly reduced. Over time, this might have allowed the genes to risk variation. Interestingly, the only other mammal with an irregular number of neck vertebrae is the sloth, another noted slacker.

But there is a downside. Slow, inquisitive, and delicious (roast dugong tastes like veal) is a bad combination when faced with Homo sapiens. All four sea cow species are now endangered as result of hunting, pollution, and damage from propellers and fishing nets. The historical precedent is grim. Their relative, the Steller’s sea cow, three times the size of the largest manatee, was hunted to extinction in the twenty-seven years after its discovery in 1741.

MANATEE COMES VIA SPANISH FROM A CARIB WORD MEANING “BREAST,” WHILE DUGONG DERIVES FROM MALAY DUYUNG MEANING “LADY OF THE SEA.” LIKE ELEPHANTS, THEY HAVE TWO TEATS UNDER THEIR FORELIMBS, CAUSING SAILORS TO MISTAKE THEM FOR MERMAIDS.

Sea Cucumber

Streetsweeper of the deep

Sea cucumbers have been trundling along the bottom of all the planet’s oceans for 500 million years. They do an essential job as marine garbagemen, processing more than 90 percent of all the dead plant and animal material that settles on the sea floor. Many of them do look like knobbly cucumbers. Their family name, Holothuridae, is thought by some to mean “completely disgusting.” The Romans called them phallus marinus, presumably because of their shape, and even Darwin dismissed them as “slimy and disgusting.” One Mexican species, Holothuria mexicana, is known as the Donkey dung: a perfectly accurate, if unflattering, description.

THE INNER CUKE

Despite their shape, the eleven hundred species of sea cucumber are close relatives of the starfish and the sea urchin, sharing the same fivefold body symmetry and, like them, moving on tube feet driven by piped seawater. But cukes, as marine biologists call them, have other tricks. They breathe through their bottoms, drawing in water through their anus to fill a respiratory tree and then expelling it along with any digestive waste that might be lurking. Single hole: two functions. This fact has been exploited by the tiny eel-like pearlfish. They wait until the cucumber’s anus opens in the morning and then sneak inside, spending a leisurely day swimming around the intestines, before emerging again to feed at night. Some even knock to gain entry. Juvenile pearlfish are less welcome as they have a habit of gnawing on the cucumber’s gonads.

SEA CUCUMBER WAS AUSTRALIA’S FIRST FOOD EXPORT. ABORIGINES ON THE NORTHERN COAST TRADED THEM WITH INDONESIAN FISHERMEN FROM AS EARLY AS THE SIXTEENTH CENTURY.

Cukes are nocturnal and need to fill their guts at least twice a night, so life mostly alternates between sand-vacuuming and resting. If they are stressed or threatened, they have an impressive array of escape strategies. Their bodies are made from a connective tissue called catch collagen, which gives them an almost miraculous ability to change from solid to fluid. This enables them to pour into the tiniest crevices and then stiffen again so they can’t be extracted. Some species can blow themselves up to the size of a football. Others expel water to make themselves look like pebbles, but the ultimate cucumber party trick is to blow their guts out of their bottom and flood the surrounding water with a toxic soup. Known as a “cuke nuke,” this can wipe out all the fish in a small aquarium, as well as the cucumber itself.

Some species have a more sophisticated version, expelling fine sticky threads, known as Cuvierian tubules, out of their backsides. These form an astonishingly sticky net that can tie up a hungry crab for hours. On the Pacific island of Palau, islanders milk cucumbers of their tubules and bind their feet with them to make improvised reef shoes. They are also used as a sterile dressing for wounds. Amazingly, a cucumber that has been harvested of its guts, gonads, or tubules can grow them back within a couple of months.

Dried sea cucumber, known as trepang or bêche-de-mer, is eaten as a delicacy all over Asia, and has a reputation as both an aphrodisiac and a painkiller. The global sea cucumber market has grown to $4.6 billion and this is putting pressure on some species, leading to the establishment of cucumber farms and sea ranches.

Seal

The grizzly submarine

Don’t be fooled by their cute looks: the seals’ closest relatives are bears, and they can be every bit as vicious. One of the ways you can tell if a leopard seal (Hydrurga leptonyx) is in the area is an empty penguin skin floating on the water. They violently shake the hapless bird from side to side to remove its coat and then gulp down the naked corpse. They are almost as bad with their loved ones. The male southern elephant seal (Mirounga leonina), six times larger than his partner, occasionally gets carried away during copulation and accidentally crushes her skull between his massive jaws. And when female Hawaiian monk seals (Monachus schauinslandi) come into heat they risk being “mobbed,” which is the polite scientific term for being battered to death by a gang of amorous males. In order to save the species from extinction, males are now being put on libido-suppressing drugs.

“SELKIES,” THE LEGENDARY SCOTTISH SEAL WOMEN WHO LEAVE THEIR SKINS BEHIND AND ARE TRICKED INTO MARRIAGE BY HUMANS, MAY BE A DIM FOLK MEMORY OF VISITS BY SHAMAN FROM LAPLAND, WHO DRESSED IN SKINS AND USED HEALING MAGIC. SEAL IS A SAAMI WORD.

HOW TO TELL A SEAL FROM A SEA LION

With elephant seals, and their close relatives the sea lions, this male aggression is also backed by huge size. The bigger and more aggressive the male, the bigger his bit of breeding beach and the higher the number of females he gets to service. A single male might have up to fifty females in his harem, but some harems grow as large as a thousand, serviced by just thirty males, with the top five—the beachmasters—getting most of the action.

Much of the intermale violence is just noise—loud gargling and slaps—but when fights do break out they can be bloody for both the participants and innocent bystanders. The females don’t help: they make such a racket during mating that every male in the area makes a beeline toward them. In the resulting melee, pups get separated from their mothers and are crushed or flung out of the way. Some colonies lose two-thirds of the pups in a single season in this way. It is one of the reasons seals’ milk has the highest fat content of any mammal’s: to ensure the pups grow quickly. The milk is more of a pudding; at 60 percent fat it’s twice as rich as whipping cream. Unsurprisingly, pups put on several pounds a day and are weaned within a few weeks.

It is in the sea that the seal’s strength and aggression really sets it apart. A seal hunting in water is twice as efficient as a lion on land. Elephant seals can dive for two hours at a time and reach depths of five thousand feet. They expel all the air from their lungs to avoid the risk of the bends and survive on the oxygen absorbed in their blood. Their bodies hold twice as much blood as most mammals and, when diving, their heart rate plummets from ninety to just four beats a minute. To help them sink faster, some will even swallow stones.

Better still, a seal’s eyes don’t go blurry underwater. In other mammals, this blur is caused by the outer lens (cornea) being rendered useless by the water, like a transparent glass marble that disappears when you drop it in the bath. Seals overcome this through a huge spherical inner lens to focus the image, and an extremely adjustable iris to control the light. This not only gives them their big-eyed charm, it also means they can hunt in bright sunlight and the gloomy ocean depths.

Shark

Big girl’s blouse

Only one in a hundred shark species attacks people. In 2005 there were just fifty-eight shark attacks reported worldwide. Only four people were killed. Wasps kill as many people in Britain every year, and jellyfish in the Philippines kill ten times as many. In the United States, both dogs and alligators kill more people than sharks. To put it another way, in an average year in New York there are sixteen hundred cases of people biting people. Sharks have far more reason to be scared of us. We kill at least seventy million a year for food (despite the fact that some shark flesh tastes of urine; both rock salmon and huss are sharks) and for their livers (which are used in hemorrhoid cream).

RADIOHEAD

Swimming perpendicular to the earth’s magnetic field induces an electric current in the Hammerhead’s head.

It sweeps its head across the sea floor like a metal detector and can pick up signals as faint as half a billionth of a volt.

The odd shape of the Hammerhead shark allows a greater separation between the electroreceptor pores on its head, enabling it to sense in stereo.

It’s lucky sharks find people a bit on the bony side and prefer seals. They are armed with a terrifying range of surveillance equipment. Two-thirds of a shark’s brain is dedicated to smell: it can detect blood diluted in water at strengths of one part in a million and from a distance of a quarter mile. Nor does lunch have to be bleeding for the shark to know it’s there. Shoaling fish exude chemicals to warn colleagues when danger threatens. Sharks intercept these signals, scenting fish that are not even wounded, merely nervous. A shark’s ability to detect low-frequency sounds means it can hear the very heartbeats of fish from far away, and pressure-sensitive receptors along its body allow it to feel the remote movements of prey through the water. Cells under the skin of its head enable it to pinpoint tiny changes in magnetic fields and minute electrical impulses. These not only help it to navigate as if using a compass, but also provide yet another killing aid: sensing individual muscle movements of a distant fish even when buried under sand. Some sharks even have a depth gauge in their middle ear. Equipped with this sophisticated gear, predatory sharks are able to hunt in total darkness.

Although in daylight they have perfectly good eyesight, these night raids must be their undoing. Items found in sharks’ stomachs include beer bottles, bags of potatoes, a tom-tom drum, car license plates, bricks, a suit of armor, and a whole porcupine. A single tiger shark was found to have swallowed three overcoats and a raincoat, some trousers, a pair of shoes, a driver’s license, a set of antlers, twelve intact lobsters, and a whole henhouse full of partly digested chickens.

The female frilled shark holds the world record for the longest pregnancy in nature: more than three years. The largest egg in nature belongs not to the ostrich but to the female whale shark. Discovered in 1953, it was twelve inches long, six inches wide, and four inches thick. The embryos of female sand tiger sharks kill and eat each other in the womb.

Since record keeping began in 1580, fewer than twenty-five hundred shark attacks on humans have been reported. This is equivalent to about 6 percent of the number of Americans injured by lavatories in 1996 (43,687).

IF YOU TURN A SHARK UPSIDE DOWN IT WILL GO INTO A TRANCELIKE STATE, CALLED TONIC IMMOBILITY FOR FIFTEEN MINUTES. NO ONE KNOWS WHAT CAUSES IT.

Male sharks do not have penises. Which probably explains a lot.

Sheep

A thank-you note

Domesticated sheep (Ovis aries) may only exist because of humans—but we, in our modern form, only exist because of sheep. First domesticated in the Middle East and Central Asia around 9000 B.C., some time after dogs, reindeer, and goats, all modern sheep can trace their lineage back to two ancestral breeds, one probably extinct, the other, the tiny—and now endangered—mouflon (Ovis musimon). Sheep, even more than their close relatives the goats, were responsible for the greatest lifestyle shift in human history: the transition from hunter gatherer to farmer. Goats were perfect for nomads, but sheep, because of their tendency to flock and their ability to graze on the toughest grass, allowed us to stay in one place. Sheep fertilized the ground they grazed on, allowing agriculture to flourish, and their flesh and milk gave us a break from hunting. To get the best out of sheep, they needed to be herded and guarded, leading to larger human settlements (and more work for the recently domesticated dog). Interestingly, the Latin for sheep, ovis, and the English ewe both derive from the Sanskrit avi, which has its roots in av, meaning “to guard or protect.” Looking after sheep gave us civilization.

It took three thousand years for our ancestors to discover that by selectively breeding sheep they could encourage their fluffy undercoat to grow longer than the bristly guard hairs (called kemp). The result was first felt and then wool, and suddenly humans had yarn, then looms and textiles. If sheep farming was the first industry, wool became the first great trade commodity. By the Middle Ages, wool drove the economies of Europe: the Renaissance was largely financed on the profits from the wool trade. Today, synthetic fibers have dramatically reduced wool production in Europe and America: 60 percent now comes from Australia, New Zealand, and China.

SHEEP THAT STAND OUT IN A FLOCK

Outlier
Goes off on its own, usually because it’s weak and hungry.

Bellwether
Sheep wearing a bell, that other sheep follow—often a castrated ram.

Riggwelter
Sheep that has fallen on its back and is too heavy to get up.

Perhaps this apparent readiness to offer themselves up for our benefit has fed into their cultural role, which, historically, has been all about sacrifice. Unlike the more sexually suggestive associations attached to the goat, sheep have invariably found themselves being offered up in thanks, or having to symbolize innocent victimhood. The sacred texts of Judaism, Christianity, and Islam overflow with lambs, flocks, and shepherds. More recently, sheep have become a byword for conformism and stupidity, which is not only ungrateful but wrong. Far from being dim, sheep have good memories: they can recognize faces of other flock members and the face of their shepherd for up to two years. This facility has long been known by hill farmers, whose flocks have become “hefted” to a particular territory. Shepherds and dogs initially teach them which ridges, boulders, and streams mark the grazing boundaries. The ewes then teach this to lambs, and it gets passed on from generation to generation, sometimes stretching back hundreds of years. The loss of hefted flocks was one of the hidden costs of the 2001 outbreak of foot-and-mouth disease, in which seven million British sheep were slaughtered. More recently, supersmart sheep have learned how to cross cattle-grids by taking a good run-up and then rolling up in a ball to cross them, commando-style.

SOAY SHEEP FROM ST. KILDA WERE ISOLATED FOR FOUR THOUSAND YEARS AND REVERTED TO A FERAL STATE. THEY HAVE TO BE PEELED, NOT SHORN, AND STARE IN BLANK INCOMPREHENSION AT SHEEPDOGS. ALL YOU NEED TO KEEP THEM IS A PAIR OF BINOCULARS.

Snake

Happy eater

No one is born with a fear of snakes: it has to be learned. Even then it’s not really rational. In Florida, which is home to more than seventy different types of snake, five hundred times as many people are bitten by dogs and far more people die from both bee stings and lightning strikes than from snakebites. The chance of being hurt in a road accident in Florida is at least a hundred times higher than that of being bitten by a snake. Snakes are not aggressive and do not chase after people. Even if they did, you’d just walk away. A rattlesnake travels at a top speed of 2 mph. The fastest snake ever recorded, a black mamba (Dendroaspis polylepis, “many-scaled wood snake”), clocked in at only 10 mph.

The smallest known snake is the burrowing thread snake (Leptotyphlops bilineata, “double-lined skinny blind-eye”). It is six inches long and as thin as a matchstick. No one knows how large the largest snakes are because the really big ones have never been brought back to be measured scientifically. At the beginning of the twentieth century, a reticulated python on the island of Celebes was said to be 33 feet long, and a green anaconda in Colombia reportedly measured 37.5 feet. No snakes as long as these have been reported for a hundred years. Snakeskin is so valuable that no snake survives long enough to grow to that size.

SNAKES HAVE TWO PENISES HIDDEN INSIDE THEIR BOTTOMS. THE ONE ON THE RIGHT IS OFTEN LARGER, SUGGESTING THAT THEY ARE “RIGHT-PENISED” IN THE SAME WAY MOST HUMANS ARE RIGHT-HANDED.

The lips of the boa and the python are the most sensitive heat detectors in nature. They can sense temperature differences of one thousandth of a degree between an object and its background and judge its direction and distance with similar accuracy. Such snakes find and kill their prey in total darkness by sensing their body heat alone. The heat detectors of rattlesnakes and pit vipers are so acute that a deaf, blind snake that has had its tongue cut off can still accurately strike its prey. Many snakes can taste air and see heat.

WHEN DINNER’S BIGGER THAN YOUR HEAD

Snake jaws don’t dislocate: all the bones of the skulls are joined by elastic ligaments, allowing the mouth to open to 150 degrees.

Lower jaws move independently of each other, alternately ratcheting or “walking” prey into the throat.

There is no such thing as a vegetarian snake. Snakes eat nothing except other animals. Anacondas and pythons can open their mouths wide enough to swallow deer and goats whole, and a python is easily a match for a leopard or a crocodile. Whether they get indigestion is not known, but the powerful acids in their stomach mean a snake will explode if given Alka Seltzer. Most snakes eat once a week; some only eight or ten times a year. After a big meal, a python can go for a whole year without eating, and female adders don’t eat for eighteen months.

Keen sunbathers, snakes, like many other animals that strike fear into people, do not like to be disturbed. When this happens, most of them wriggle away. The Sonoran coral snake (Micruroides euryxanthus, “yellow-banded small-tail”) accompanies this with small, regular, high-pitched farts. Grass snakes (which are otherwise harmless) emit a disgusting stench of rotten garlic from their anal glands. They then vomit the contents of their stomachs all over the path. If that doesn’t put you off, they flip over on their backs and lie motionless with their mouths open and their tongues lolling out. Whether this is a defense mechanism or just bad acting is unknown. Most researchers never get close enough to ask them.

Spider

Worldwide webmaster

If spiders didn’t exist, we’d have to invent them; without them, we’d simply drown in insects. Until the late eighteenth century, we just assumed they were wingless insects, but they now have their own class, Arachnida, which contains forty thousand identified species, with as many again waiting to be named. They were one of the earliest land animals to evolve and are predatory, territorial carnivores: put ten thousand spiders in a sealed room and you will eventually end up with a single fat spider. The mass of insects eaten by British spiders in a year outweighs the U.K.’s human population. And by “eat” we really mean drink: they dissolve their victims first.

That’s an impressive trick, but not unique to spiders. What spiders do best is spin webs. Spider’s silk is five times stronger than steel and thirty times more stretchy than nylon. It is so light that a strand long enough to circle the world would weigh the same as a bar of soap. It is made from protein strands and water spun together; the protein gives it strength, and the surface tension of the water lends it elasticity—but we still don’t really understand how it’s done. An average spider will spin more than four miles of silk in a lifetime, and this can be collected and woven into garments. However, their predatory nature makes them tricky to farm, so we will have to wait for genetic engineering to deliver spider-silk parachutes, bullet-proof vests, and artificial tendons.

Some spiders use their webs to fly. Called “ballooning,” it involves them climbing to the top of a fence, pointing their backsides into the air, squirting out a long line of silk, and letting the breeze take them. They can travel immense distances and have been found as high as sixteen thousand feet. Spiders can create perfect webs almost anywhere, even in zero gravity, but give them drugs, and they lose the plot. In 1995 a NASA experiment revealed that marijuana made them lose concentration halfway through spinning, whereas amphetamines made them spin quicker but much less accurately. Caffeine was the most extreme: the coffee web consisted of a few threads randomly strung together.

THE TARANTULA’S BITE WAS SUPPOSED TO BRING ON EXTRAORDINARY SYMPTOMS: STUPOR, INVOLUNTARY ERECTIONS, AND AN UNCONTROLLABLE DESIRE TO DANCE OFF THE VENOM IN A VIOLENT AND ENERGETIC DANCE (THE TARANTELLA) FOR MORE THAN THREE DAYS. IT TURNS OUT IT WAS ANOTHER SPIDER’S BITE THAT BROUGHT ON THESE SYMPTOMS.

Male spiders don’t have a penis. To mate they ooze drops of sperm onto a special sperm web. They then suck this up into one of a pair of specially adapted mouthparts called pedipalps. The pedipalps insert, twist, and lock it into the corresponding female slots and pump in the sperm, rather like R2-D2 uploading into a mainframe. Often the end snaps off on completion. Inserting these pedipalps can be a perilous business for the male: his partner can be a hundred times his size. In one species, the tent cobweb weaver (Tidarren sysiphoides), the male chews off one of his pedipalps beforehand to gain a speed and mobility advantage over the other suitors. He usually dies on the job, his dead body keeping his sperm safe from competitors for several hours. The male Australian redbacks (Lactrodectus hasselti) actually compete to be eaten. Being devoured by the female ensures that their pedipalp gets in first.

Despite their reputation, female black widows only eat one in ten of their mates, although they can get through twenty-five partners in a day.

Although spiders are surrounded by fear and superstition, humans do sometimes eat them. The Piaroa people of Venezuela consider the world’s largest spider, the goliath bird-eating tarantula (Theraphosa leblondi), a delicacy. Roasted, they yield a quarter-pound of prawnlike white meat and are served with their fangs on the side, as toothpicks.

Starfish

No brain, clever feet

Starfish aren’t fish; they are much older. The echinoderms (“spiny skins”), which also include sea urchins and sea cucumbers, first appeared in the early Cambrian period, about 550 million years ago, and haven’t changed much since. Unlike mollusks and insects, they have an internal skeleton made from plates of calcium carbonate called ossicles. This makes them the direct relative of all vertebrates, including humans.

They don’t have a central brain, but being star-shaped, they don’t have a front or back either. The nearest they get is a ring of nerves that runs around their mouth. From this an individual nerve runs down each leg. As one leg moves—usually the one closest to food—it lets the others know to follow it. A splendid advantage to this system is that starfish can regenerate lost limbs, and in the case of the Linckia species, the lost limbs can even regenerate a new starfish. The early stages of this process—one large arm, a tiny body and four tiny arms—look like small seaborne comets.

Starfish have a mouth (underneath) and an anus (on top) but they arrived a long time before ears, eyes, or noses. Instead, they have hundreds of multitasking tube feet covering their underside. They use these to breathe, to move, and to attach themselves to prey. They also function as noses, assisted by the skin’s sensory cells (2.6 million per square inch), responding to chemical changes in the water around them, and locking on to odor plumes given off by potential food. At the tips of the legs, eyespots (which may be mutated feet) act as light sensors.

IN BUSINESS JARGON, A STARFISH ORGANIZATION IS COMPLETELY DECENTRALIZED. ON THE OTHER HAND, PASSIVE SEXUAL PARTNERS ARE SOMETIMES DESCRIBED AS STARFISH BECAUSE THEY “JUST LIE THERE.”

Starfish move using simple hydraulics. They take in seawater through a special sievelike opening called a madreporite and distribute it internally to all the tube feet. By squeezing and sucking water in and out of the feet in sequence, they can move surprisingly quickly. Some species manage three feet a minute.

Series of water-filled suckers propels starfish along surfaces.

Starfish sex is a strictly arm’s-length business. Each leg contains a large sex organ, but short of dissecting them it is impossible to tell male from female. They gather in groups when spawning, and the male releases sperm into the water if he detects eggs; the female releases up to two and a half million eggs at a time if she detects sperm. The larvae are completely unlike their parents and look more like free-swimming plankton. Eventually they grow arms, sink to the bottom, and stick to a rock, before metamorphosing into adults.

THE STARFISH DINER

Fully grown starfish have few predators; their spiny skin is covered in tiny pincers that nip at anything that annoys them. They also groom the skin, keeping it clear of parasites. One species, Luidia, just disintegrates into fragments if it gets caught.

Starfish eat almost anything too slow to escape, particularly mussels and oysters. A square-mile army of starfish was recently sighted off Le Morbihan in France, at a density of fourteen to the square foot, moving slowly across the ocean floor and consuming everything in its path.

Tapir

Ancient forest horse

When Stanley Kubrick cast tapirs alongside early hominids in the opening sequence of 2001: A Space Odyssey, it was because they seemed prehistoric. He was right: they may look like the result of a night of passion involving a pig and an anteater but tapirs are the last survivors of a large family of mammals that have changed little in 20 million years. At one point they were found on every continent (except Antarctica), but now there are only four species left: three in Central and South America and one on the other side of the world in Southeast Asia.

Tapirs are perfectly adapted to life in warm, wet forests. They can graze on the forest floor for fallen fruit and browse higher up for green twigs and ferns. Their stout bodies barrel through thick undergrowth at high speed and they are as happy in the water as on dry land. But the key to their early success remains their most distinctive feature, a short, multidirectional trunk—the ultimate accessory for forest life. It gave them greater reach when feeding, functioned as a snorkel for traveling underwater, and provided a continuous olfactory readout on the presence of food, or the possibility of sex.

But the climate has changed, and cooler, drier conditions have seen forests replaced by grassland, which favors grazing ruminants, not shortsighted, semi-aquatic fruit-chewers. Unlike their closest relatives, horses and rhinos, tapirs haven’t managed this transition, and now all four surviving species are endangered.

THE THAI WORD FOR TAPIR IS P’SOM-SETT, WHICH MEANS “MIXTURE.” IT COMES FROM THE BELIEF THAT THE TAPIR WAS MADE FROM THE LEFTOVER BITS OF ALL THE OTHER ANIMALS.

As well as the loss of habitat, tapirs are also threatened by human predation. Hundreds are poached each year for their fatty meat (often sold as buffalo), their durable hide (tapira is a Brazilian Indian word for “thick”), and the various parts of their anatomy still used as folk cures for heart disease and epilepsy. In many Amerindian tribes, the Milky Way is known as the Tapir’s Way, in the same way the American Plains Indians call it the Path of the Buffalo. In China and Japan, their name means “dream-stealer.”

Other than humans, tapirs are too strong and nimble to have many predators. Occasionally, a big cat will take one on, in which case the tapir simply leaps into a nearby stream and sinks until the cat is forced to let go. Tapirs like walking on the bottom of streams and ponds: it cools them down and allows fish to strip their hide of parasites.

Tapir calves look very different from their parents: they are striped and spotted, like furry watermelons. This provides surprisingly good camouflage in the dappled shade of the forest, but they still fall prey to the giant anaconda, which likes to swallow them whole. Although we call their offspring calves, zoologists have now agreed that tapirs are sufficiently different from other hoofed mammals not to call the adults bulls and cows.

Tapirs are the least well-studied of all large mammals. We don’t know whether they mate for life, how their family groups work, where they sleep, or the function of their strange birdlike whistles. But this is changing. Their importance in the ecosystem of the rain forest has made them a conservation landmark species. Just as they need the forest to survive, so many of the forest fruiting plants depend on the tapir’s digestive tract to propagate. Saving the tapir will help save the rain forest, too.

FOURTEEN TOES AND ONE FINGER

Tardigrade

The bear that wouldn’t die

Tardigrades are the toughest animals on the planet. Also known as water bears and moss piglets, they sound cute, but don’t be fooled. They live anywhere there’s water—five miles down in the ocean; on the polar ice caps; in radioactive hot springs; on top of the Himalayas; on forest floors; on the bottom of lakes; on wet beaches; in Alpine meadows; in the miniature ponds created in the cups of leaves; in the moss on your roof; on the ground where your dog pees each morning. They are plump, microscopic animals that fall somewhere between the annelid worms and the insects. Only a twentieth of an inch long, they have a head, four pairs of stubby, clawed legs, and a sausage-shaped, opaque body. They’re called water bears because of the way they look and move (although they’re more like a section of frayed, rumpled leg warmer) and moss piglets because moss is one of the best and easiest places to find them.

A TARDIGRADE IN SUSPENDED ANIMATION IS CALLED A TUN, BECAUSE IT LOOKS A BIT LIKE A TINY WINE BARREL.

There are eight hundred recorded species of tardigrade, with at least ten thousand still to be named, and they are distinctive enough to have their own phyla. Most land dwellers feed on plants and fungi, but many are carnivorous, sucking up nematode worms, rotifers, and other tiny creatures. The water dwellers (who can live one hundred thousand to the pint) seem to survive without eating at all for long periods, although some are parasites, living on sea cucumbers and barnacles. Many species are all female. As they aren’t speedy at getting around (tardigrade means “slow stepper”), they rely on the wind or splashing raindrops to move them to new habitats. Under those circumstances, being able to fertilize your own eggs is a definite advantage: you can populate a new clump of moss all by yourself. Other species reproduce sexually, in a topsy-turvy kind of way (the female inserts a tube into the male and steals his sperm). Tardigrade eggs are spectacularly beautiful, shaped into multi-pointed stars and dimpled spheres that look like chic lamp-shades, although their practical function is to keep their contents moist and safe from being squashed.

What really sets tardigrades apart is their ability to enter a state of suspended animation. If their water supply dries out, they dry out, too. All life processes come to a complete halt and they become totally inert—but they are not dead. This condition, known as cryptobiosis, was first identified in 1776. Some scientists believe it may hold the clue to the origins of life itself. The tardigrade expels all its water and breaks down its cell fats into a sugar called trehalose, which binds and protects all its vital organs. Then it waits—for as long as a hundred years—for a single drop of water to revive it.

In this “dead” state, tardigrades are practically indestructible. They have been frozen to within a degree of absolute zero (–459°F) and heated to temperatures of 304°F. They have been placed in liquid helium for a week, and given doses of radiation a thousand times greater than the fatal dose for a human. They have been immersed in chemicals and squeezed by pressures six times greater than those at the bottom of the ocean; but like living granules of instant coffee, with one drop of water, back to life they come.

INSIDE THE RESURRECTION MACHINE

Cross section of self-fertilizing tardigrade

Termite

Family values

Termites have evolved the most sophisticated family organization of any animal and it’s based around monogamy. Despite living in colonies containing millions of individuals, breeding termites mate for life. Some species only have one king and queen per colony; others have several and, unlike those of ants or bees, these are proper marriages, not brief flings: there are couples still mating years later. This has helped make termites, with ants, the most successful insects of all: if you added all twenty-six hundred termite species together, they would account for 10 percent of the planet’s total animal biomass. Unfortunately, their high-fiber diet means they also produce 11 percent of global methane emissions, second only to ruminants like cows and sheep.

DIDGERIDOOS ARE MADE FROM EUCALYPTUS LOGS HOLLOWED OUT BY TERMITES.

But life doesn’t always run smoothly, even for termites. In the species Zootermopsis nevadensis the divorce rate is running at about 50 percent. Sometimes the males walk out; often the female invites in a new male with predictably violent results. Touchingly, rejected termites tend to take up with one another. Marriage leaves the male termite relatively unaffected, although he usually dies first. The queen, however, can swell to three hundred times her original size, as her ovaries expand. The queen of the Indian mound-building termite (Odontotermes obesus) lays an egg a second, or more than eighty thousand a day. If the nest is attacked, the workers have to drag her to safety, as she is too fat to move of her own accord.

To make things worse, termites are in the middle of an identity crisis. In 2007 DNA research revealed that they are actually cockroaches. Their former order Isoptera (“equal wing”) has been abandoned and they have been moved into Blattodea (blatta is Greek for “cockroach”). The theory is that they evolved from their cockroachlike ancestors when they developed the ability to eat wood.

It’s the blind workers who do the wood-munching, feeding the rest of the colony from their mouths or bottoms. They are like mini cows, with a multichambered stomach to break down cellulose. Their guts are home to two hundred types of microbes, which all help turn the wood into energy. Studies of these tiny organisms are being funded by the biofuel industry to see if they hold the key to extracting clean-burning fuel from corn. In some species, workers arrange their droppings into combs that grow fungi, ensuring a supply of rich protein, even during the dry season.

HOW DOES YOUR WOOD SOUND?

Termites decide on which wood to eat by the vibrations it gives off when they start chewing. They prefer smaller pieces of wood (like furniture) to whole trees. Wood fibers snap when chewed, sending an impulse through the body, revealing the wood’s type and size.

A termite nest is the most complex animal structure not built by us. The external mound can be more than twenty-five feet high, protecting the nest from the fierce sun, acting as an air-conditioning duct by releasing the heat and carbon dioxide generated by the termites and their fungus gardens, and replacing it with fresh oxygen. The Formosan subterranean termite (Coptotermes formosanus) even fumigates its nest with naphthalene to repel ants and nematode worms. As it doesn’t occur naturally, no one knows how—or from what—it is made.

TERMITES CAN BURROW THROUGH CONCRETE. IN NORTH AMERICA, THEY CAUSE MORE DAMAGE THAN FIRES AND FLOODS PUT TOGETHER; THE ANNUAL GLOBAL TERMITE DAMAGE BILL NOW EXCEEDS $5 BILLION.

Termites are one of the most popular culinary insects: they contain 75 percent more protein than rump steak. In the Amazon basin, the Maue tribe barbecue them while the Kayapo fry them in their own juices or use them crushed as a condiment. In Nigeria you can buy termite stock cubes.

Toad

When amphibians explode

Few animals spook us like the toad. The witch’s right-hand animal, they have been feared throughout history as ugly, poisonous creatures of the night. Touching them might give you warts and meeting their stare could turn you epileptic.

In East Anglia, to become a toadman was to make a pact with the Devil, the most dangerous initiation ritual of British folk magic: all your power was focused in the bone of a toad, which no one else was allowed to see or touch.

“TOADY” (AS IN “SYCOPHANT”) COMES FROM “TOAD-EATER,” ONE HALF OF AN EIGHTEENTHCENTURY PAIR OF CON ARTISTS, WHO WOULD SWALLOW A TOAD IN PUBLIC AND THEN BEG HIS QUACK DOCTORPARTNER TO CURE HIM WITH A MAGICAL ELIXIR.

Wearing the legs torn from a toad guarded against skin disease. Carrying its tongue made you irresistible to women. Breast cancer could be cured by rubbing a live toad over your chest, and the best protection against witches was to bury a toad in a bottle near your door or hearth. Killing them was strictly taboo.

Despite all the bad press, toads, taxonomically speaking, are members of the frog family. There are 350 species, and the main differences are skin and teeth. Frogs tend to have tiny teeth and smooth skin; toads have no teeth and thick, warty skin, and usually walk rather than hop.

Also, unlike most frogs, toads are poisonous. They secrete a milky fluid from their warts and from a pair of glands behind their eyes—the toad spittle of legend. In some species this venom contains hallucinogenic compounds and can be milked for recreational use. Unfortunately, it also contains powerful steroids that cause irreparable damage to the heart. Licking or kissing toads is likely to make you sick long before it gets you high.

Twenty tons of toads are squashed on British roads every year. This is because they have followed the same path, century after century, to ancient breeding ponds, which often means crossing busy roads. Specially built subterranean toad tunnels have helped, easing the passage of as many as fifteen hundred toads in a single evening.

Toad-in-the-hole was originally steak encased in batter, until steak became too expensive and was replaced by sausages. The name was taken from a now forgotten public craze of the nineteenth century. Hundreds of examples were reported of live toads being discovered entombed in the middle of ancient rocks. Toad-in-the-hole hysteria peaked in the 1830s when William Buckland, the Oxford professor of geology, buried a number of toads in stone blocks to test their survival skills. Although some lived for as long as two years, most died and public fascination waned.

The male midwife toad (Alytes obstetricans) fertilizes several females—and then gets to carry the eggs himself.

A more recent toad mystery took place in a Hamburg pond in 2005, when toads started exploding during the mating season. More than a thousand toads, swollen to three times their usual size, crawled out of the water, making eerie screeching noises, and blew up, propelling their entrails up to a yard away.

Initial suspicions of a virus or industrial pollution turned out to be wrong. The toads were being attacked by supersmart crows. The birds had worked out that, with a single strike through the toad’s chest, they could remove its liver. The toad’s own defense mechanism did the rest. As they puffed themselves up to intimidate their attacker, they forced their own intestines out through the wound at high pressure, in a kind of fatal hernia.

Tuatara

Three-eyed loner

Most species described as living fossils struggle to fully justify the claim, but not the tuatara. This ancient reptile looks like an iguana, but it isn’t a lizard. Nor is it a dinosaur, although it has changed little since the days of the giant reptiles. It’s a sphenodon, or “wedge tooth,” the last member of an order that once covered the planet. The tuatara has survived for two reasons. Firstly, it happened to find itself on the small landmass that became New Zealand about 80 million years ago, as it split from Gondwanaland, the southern supercontinent, before mammals had established themselves. And second, it found a way of adapting to a colder climate.

Most of the sphenodons disappeared with the dinosaurs; those that didn’t got hustled out of their niches by mammals. The tuatara ploughed its own furrow quite happily for millions of years, until the mammals finally reached them, paddling canoes. With the canoe mammals came others, most notably dogs and rats. The tuataras were gradually driven from the mainland and now survive only on islands dotted around New Zealand’s coast.

Their main disadvantage in the battle with mammals is metabolism. Tuataras are the most primitive of all living reptiles. Their brain is tiny, more like an amphibian’s than a lizard’s. Their heart and circulatory system are also rudimentary, making them extremely cold-blooded, and they live on islands that are often wind-battered and chilly. Out of necessity, Do It Slowly has become the tuatara’s motto. They grow more slowly than any other reptile. It takes them fifteen years to reach sexual maturity and even then, the females only manage to produce a clutch of eggs every four years, which take more than a year to hatch. Their method of hunting is to sit outside their burrows at night waiting for beetles, worms, crickets, or—best of all—a young tuatara to toddle past. Their method of defense is to sit inside their burrow waiting for the danger to go away. That’s no challenge for a sprightly rat. In 1981 the island of Whenuakura had a population of two hundred tuataras. By 1984 they had gone, replaced by a colony of rats.

TUATARA MEANS “SPIKY BACK” IN MAORI. THE MAORI ONCE ATE THEM, BUT ONLY THE MEN; A WOMAN WHO BROKE THE RULE RISKED BEING KILLED IN VENGEANCE BY THE ENTIRE TUATARA POPULATION.

Several features set the tuatara apart from their lizard cousins. They can live for well over a hundred years. They don’t have teeth but all-in-one serrated jawbones: in old tuataras these jaw “teeth” are worn smooth, leaving them to gum their way through slugs and earthworms. Also, unlike the doubly endowed lizards, tuataras have no penis: they reproduce by pressing their bottoms together, like birds and (probably) dinosaurs.

Oddest of all is the third eye in the middle of their forehead. Although scales grow over it by the time they are six months old, it is a real eye with a lens, retina, and a nerve connection to the brain. It appears to be light-sensitive and might help in regulating body temperature. Temperature matters to a tuatara: they live cheerfully in conditions that would trigger hibernation in most reptiles (50°F), so heat can kill them. Rising temperatures also pose a more serious threat. As with turtles and crocodiles, the sex of the hatchling is determined by the heat of the egg. The warmer northern colonies of the fifty-five-thousand-strong tuatara population are now producing twice as many males as females.

HOW TO CATCH A TUATARA

Walrus

A violent lunch companion

The word “walrus” may be from Dutch walros (“shore-steed”) and its Latin name Odobenus rosmarus means “tooth-walking sea-horse,” but walruses look nothing like horses. They are almost as round as they are long, they have no visible ears, and they drag themselves along by their teeth. They also change color when heated, from off-white to pink to cinnamon brown. A beach heaving with basking walruses looks like a skip-load of deformed cocktail sausages.

THE WALRUS IN LEWIS CARROLL’S 1871 POEM “THE WALRUS AND THE CARPENTER” WAS INSPIRED BY A STUFFED SPECIMEN IN SUNDERLAND MUSEUM, OF WHICH ONLY THE HEAD REMAINS. THE POEM, IN TURN, INSPIRED JOHN LENNON’S ACID ANTHEM “I AM THE WALRUS” ON MAGICAL MYSTERY TOUR.

Walruses are inordinately fond of seafood. They enjoy cockles and mussels, crabs, shrimp, snails, and octopus and can wolf down more than six thousand clams in a single meal. Clams bury themselves in the seabed, so the walrus first has to unearth them. To do this, it brushes the sediment away with a flipper and it almost always uses the right-hand one. There are no southpaw walruses. It was long assumed that all animals are ambidextrous, but recent research has shown this is not so. In addition to walruses, whales, chickens, and toads tend to lead with their right, whereas frogs and lizards favor the left.

Another way that walruses feed is to create a high-pressure hose effect using their lips and tongues to blast the sea-bed and expose their lunch. This creates a thick murk of sand and debris, so, rather than using their small eyes to identify prey, they slide along feeling the bottom with their moustaches. These are composed of more than four hundred incredibly sensitive whiskers, known as vibrissae, Latin for “vibrators.” A grazing walrus can move each of them independently.

Walruses suck as well as blow. When they find a clam, they hold it firm in their lips, create a vacuum around it, and use their tongue like a piston to extract the soft tissue. As a special treat, they vaccum up seagulls from underneath or suck the brains of seal pups out through their nostrils, a party trick also used by young Inuit in Greenland to impress tourists. Walruses have a sucking power three times stronger than the average Dyson, which explains why their stomachs are full of small pebbles.

THE ARCTIC SUPERMARKET

Walruses are a one-stop shop for the Inuit

Medieval merchants used to pass off walrus tusks as unicorn horns. They are canine teeth that never stop growing; in a large male they can be three feet long. Apart from helping them haul themselves on to ice floes, they are mostly for show. Walrus society is simple: the bigger the male, the more impressive the tusks, the more lady walruses make themselves available.

Mating among walruses is much like a subzero version of a Club Med holiday. The females lounge provocatively on the ice, while being ogled by a pack of alpha males bobbing around in the water, trumping, clacking, roaring, rasping, and occasionally gouging chunks out of one another. Unlike those at a Club Med, however, the female will only mate with one male. Walrus sex takes place underwater and it’s impressive stuff. The male’s penis contains a bone almost as long as its tusks, which guarantees fail-safe operation in even the coldest Arctic seas.

Wasp

Sugar and paper

Of the thousands of species of wasp out there, there are only two that regularly bother us: the Common wasp (Vespula vulgaris) and the German wasp (Vespula germanica). There’s not much to choose between them: both live in colonies and fashion delicate spherical paper nests, both have a nasty retractable sting, and both cause a huge fuss at late summer picnics. Wasps, of course, suffer the great misfortune of not being bees: they don’t make us honey, their markings are stark and uncuddly, and their behavior seems thuggish in comparison to the mystical dances and complex social life of their furry cousins. This is unfair; for a start, bees are really just vegetarian wasps. Each of them has a job to do, and without the voracious appetite of the wasp many insect pests would overrun our gardens.

SPOT THE GERMAN

The appetite is not quite what it seems. Like bees, most of the wasps we see are sterile females, but in spite of their impressive mouthparts, they have a very simple digestive tract, which means they can only eat sweet nectar. They kill and scavenge tirelessly, but not for themselves. Their jaws are used to chew up protein for the endlessly hungry larvae back at the nest. Then, in return for bits of bacon sandwich or beetle, they get a blob of sweet, nutritious “soup” from the larva’s mouth. But at summer’s end, this food source runs out. Its breeding work done, the commune disperses; next year’s queens find a sheltered place to spend the winter, while everyone else gradually dies off. This is when worker wasps—now unemployed and unfed—become a nuisance to humans. In the last few, purposeless weeks of their lives, before cold weather finishes them off, they seek alternative sources of sugar in our kitchens, orchards, and picnics. It’s now that most human-wasp interaction occurs—sometimes with fatal consequences, for wasp and human.

IT’S A BAD IDEA TO KILL A WASP: DYING WASPS EMIT A PHEROMONE THAT ALERTS ITS NEST-MATES TO DANGER, SO YOU MAY BE SURROUNDED WITHIN SECONDS.

Often these interactions culminate in one of the humans claiming they are being attacked by a hornet. The hornet (Vespa crabro) is the largest and noisiest of the European social wasps, which no doubt explains why people have long been terrified of it. But, in fact, its sting has much less effect on humans than that of a bee. Bees have evolved their venom as a defense against honey-stealing vertebrates, including beasts the size of bears and badgers, whereas a hornet’s poison is intended mainly for use on its invertebrate prey. Analysis of hornet venom suggests that a fatal dose for a human (unless he was allergic to it) would be something like a thousand stings.

There is an important exception. The Asian giant hornet (Vespa mandarinia) of Japan, also known as the yak-killer, is the superpredator of the wasp family. They are enormous—like flying thumbs, with a quarter-inch sting. They are fast, strong, and merciless—ten of them can take out an entire honeybee colony in a matter of hours, tearing off the bees’ heads with their terrifying jaws. Their venom is strong enough to dissolve human tissue and they kill more than fifty people a year. But the Japanese get their own back in style: they serve the larvae raw as hornet sashimi and deep-fry the adults, which are reputed to taste like sweet prawns.

Whale

Supersized songsmith

Fifty-five million years ago, small hoofed carnivores started to move from the land back into the sea. Those wonderful pictures of legs becoming fins and tails, bodies becoming longer and more streamlined, nostrils moving back and up, seem to run the evolutionary clock backward. DNA evidence now shows us that whales have nothing to do with other water-based meat-eaters like seals and walruses; their closest living relative is the vegetarian hippo, with deer, camels, and pigs as very distant cousins. It’s one of evolution’s most compelling stories: how a clumsy, crocodile-shaped otter ends up producing the largest, most graceful and mysterious of all the creatures on the planet.

WHY THE BIG NOSE?

Sperm whales are one-third head. It houses a brain four times the size of a human’s and four tons of spermaceti, once thought to be the whale’s semen. Humans use it as transmission fluid, watch oil, and for putting the shine in lipstick. The whale uses it to talk.

The blue whale is the largest animal that has ever lived by a huge margin: thirty times heavier than an African elephant, the next largest mammal. The biggest dinosaur weighed less than half as much: some female blue whales can lose as much as fifty tons when feeding their young. A newborn blue whale is the same weight as a female elephant: it puts on 196 pounds a day, eight pounds an hour. When fully grown, its heart is the same size as a family car, processing two thousand gallons of blood, pumping sixty gallons a beat, with an aorta large enough for a five-year-old child to swim through.

Whales grew large because the buoyancy of water meant they could—nothing so heavy could survive on land; the energy needed to move and feed would be too great. But for a warm-blooded animal, living in the sea is problematic: it’s a desert—there’s nothing to drink. And it’s cold: heat travels twenty-four times faster in water. Being large helps, as it reduces the surface-to-weight ratio, but the real star of whale survival is blubber. It not only acts as an insulating overcoat and life jacket (it’s less dense than seawater), it also stores the water extracted from food and provides a handy on-board supply of nutrients when food is scarce.

Communicating in water is also a challenge. Smell is useless, sight limited, and touch is tricky when you have fins rather than fingers. But sound waves travel four times faster underwater, and whales have turned the ocean itself into a sophisticated communication medium. Whale song is the loudest noise made by any single animal: some songs are so low in frequency that they can be felt thousands of miles away. The massive head of the sperm whale focuses sound into a burst that can stun a giant squid but it also acts as a kind of acoustic retina, a giant IMAX sound screen through which it interprets its dark world. The half-hour songs of the humpback whale contain grammatical rules: sounds are combined into structures that operate like syntax, packing the song with millions of discrete units of information. Whales sing in different dialects depending on where they’re from, and sing different songs in different places at different times of the year.

BLUE WHALES WERE ONLY CAUGHT AFTER THE INVENTION OF THE GRENADE HARPOON IN 1868. IN 1931 29,000 WERE KILLED IN ONE SEASON. THERE ARE NOW FEWER THAN 5,000—ONE WHALE FOR EVERY 8,500 CUBIC MILES OF THEIR OCEAN HABITAT.

Whether these songs are sat-nav readouts, shipping forecasts, personal ads, or epic poetry, we will never know. What we do know is that military sonar and general noise pollution in the sea has reduced their carrying range by 80 percent, and many stranded whales have severe inner ear damage. We may not hunt whales as we once did, but we still torment them.

Woodlouse

The backyard shrimp

Woodlice are land-based crustaceans, and, despite appearances, are much more closely related to shrimps and lobsters than they are to millipedes or centipedes.

They have blue blood and still breathe using gills. These are attached to the pairs of pleopods (literally, “swimming feet”) on their abdomen and contain a branching network of moist tubes that allow them to extract oxygen from air, although a woodlouse will survive quite happily in water for up to an hour.

Woodlice have a rich array of nicknames: sow bugs, ball bugs, armadillo bugs, slaters, grammerzows, chiggy pigs, cheeselogs, bibble bugs, cud worms, coffin cutters, monkey peas, pea bugs, granny-ants, granfers, Billy Bakers, and tiggyhogs. In Holland they are called pissebed (literally “piss-in-the-bed”) because they were swallowed whole as a diuretic. Oddly, woodlice themselves don’t urinate: their porous shell also allows them to expel their waste as ammonia vapor rather than liquid urine. They produce more nitrogenous waste for their size than any other animal.

Woodlice drink through their bottoms—the uropods can also ooze a noxious chemical gum to keep spiders away.

The porous shell also means they are vulnerable to dehydration. Their tendency to clump together in large groups helps keep them moist and protects them from predators. Toads, shrews, and centipedes are all keen on woodlice. Blowfly larvae also burrow into woodlice and eat them from the inside. The woodlouse spider (Dysdera crocata) lives on nothing else and has specially adapted fangs for piercing their shells.

WOODLICE WERE EATEN AS A CURE FOR STOMACH UPSETS, RATHER LIKE TUMS—THEIR SHELL IS MADE FROM CALCIUM CARBONATE, WHICH NEUTRALIZES THE ACID IN THE STOMACH.

Woodlice do use their bottoms to drink. Small forked tubes called uropods suck water into their anuses. They’re not fussy eaters, either. They prefer rotting vegetation, but in lean months their own feces will do. There’s a New Zealand species, the sea slater (Scyphax ornatus), that survives mostly on drowned honey-bees. Their odd personal habits make them good news in a compost heap and their fondness for munching through rubbish has led to them being employed by natural history museums to clean delicate animal skeletons.

Woodlice are members of the Isopod order (meaning “equal feet”). There are 3,500 species and they’ve been around for 160 million years. They carry their young in pouches, molt regularly, and live for about two years. Not all of them clump together in damp crevices. The desert woodlouse (Hemilepistus reaumuri) pairs for life, navigates by the sun, and lives in organized colonies of burrows where the young do the housework. They can walk several miles a day.

It’s tough being a male wood-louse. Not only can females give birth without mating (parthenogenesis), but males infected with a certain bacterium actually turn into females.

The deep sea isopod (Bathynomus giganteus) is a giant aquatic woodlouse that lives on the icy darkness of the ocean floor and vacuums up dead whales. They are white, two feet long, and weigh as much as a decent-sized lobster.

Woodlice are perfectly edible. In his polemical pamphlet Why Not Eat Insects? (1885), Vincent M. Holt considered their flavor superior to shrimp and gave a recipe for a woodlouse sauce for fish.

Woodpecker

The tongue that listens

The woodpecker’s tongue is one of the most amazing of all animal organs, so much so that it often gets cited by creationists as proof that evolution is flawed. In some species it can extend to fully two-thirds of the bird’s body length, is covered in sticky saliva, has vicious barbs, and has an “ear” at the end of it. In fact, tongue structure of the woodpecker is very similar to that of most other birds: it’s just longer, presumably because this delivered the evolutionary advantage of being able to reach deeper into the tree for insects. The secret is a series of wafer-thin hyoid bones that fold up like an accordion in a fluid-filled sheath when the tongue is not being used. As the woodpecker sticks out its tongue, powerful muscles contract near the base, forcing the bones forward and the tongue out of the bill. Relaxing the muscles brings it back inside. When a woodpecker is born, its tongue is anchored near its ears, much like a chicken’s. As it grows, the hyoid sheath gradually extends around and over the skull, when it fuses with the back of the nostrils. As for the ear on the tongue’s tip, this is a concentration of pressure-sensitive nerve endings, called Herbst’s corpuscles, that feel the tiniest vibrations of insect prey.

MY FATHER TOLD ME ALL ABOUT THE BIRDS AND THE BEES, THE LIAR. I WENT STEADY WITH A WOODPECKER TILL I WAS TWENTY-ONE.

BOB HOPE

There are more than two hundred species of woodpecker, and each has a particular speed and rhythm of drilling, some reaching sixteen blows per second. Every time a woodpecker brings its head to a halt, the force is equivalent to a thousand times the force of gravity (or 250 times the force an astronaut is subjected to during liftoff). The reason that their heads do not shatter is a spongelike cartilage cushion that absorbs most of the shock. Also, every time the woodpecker strikes a blow, a muscle pulls the brain case away from the beak.

Muscles pull back the brain in sync with pecking to act as a shock absorber.

Woodpecker drumming isn’t searching for food. It’s a species signature used to communicate and attract mates. Woodpeckers often choose materials where the resonance is high—dead trees, metal drainpipes, or wooden eaves. They drum at different rates when insect-hunting or excavating nests. In 1995 a pair of northern flickers (Colaptes auratus) drilled two hundred holes into the foam insulation of the shuttle Discovery’s external tank, delaying its launch.

Green woodpeckers (Picus viridis) are also known as rain-birds—hearing their distinctive laughing call means rain is on its way. This dates back to an early version of the Genesis story, where the woodpecker refused to help God excavate the rivers and oceans and was punished by being forced to peck wood and drink rain. The bird once had forty English vernacular names including hewhole, wudewale, and galley bird, but the one still used is yaffle. Most people assume this refers to its laugh but it actually means “to eat greedily.” Which green woodpeckers do, as anyone who’s ever seen one attacking an anthill will testify. They can get through two thousand ants in a single sitting.

Worm

Wiggly woo woo

The animal kingdom is subdivided into thirty-four categories called phyla. There is some disagreement among biologists about the precise number and placing of the divisions, but everyone agrees that more than half of them (usually seventeen) are made up of various kinds of worm. There may be more species of beetle, but there are more individual worms in the world than any other type of creature. No matter how many cattle there are in a field, the worms under the soil will always outweigh the cows on top of it.

Nematodes, or roundworms, are parasitic worms found almost everywhere on earth from the ocean floor to the human gut. They are the most numerous animals on the planet, ranging from a hundredth of an inch to twenty-seven feet long. There are about 40,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000,000 nematodes all told and their DNA is 75 percent identical with that of human beings. Most nematodes are benevolent, humbly servicing the ecosystem, but some are dangerous parasites that can cause river blindness, elephantiasis, and hookworm anemia. Then there are flatworms and segmented worms, spoon worms and peanut worms, ribbon worms and horse-hair worms. Velvet worms live in old leaves and rotting logs. They paralyze animals and liquidize them with saliva. Acorn worms live in U-shaped burrows on the seabed. They eat and excrete mud. Those little coils you see on the beach at low tide are acorn worm droppings. All worms except paddle worms are hermaphrodites. Pseudoceros bifurcens is a flatworm that lives sixty feet underwater in Queensland, Australia. It performs a mating dance called “penis fencing.” The worms spend up to an hour trying to inject each other with sperm: whoever wins gets to be the male. Ribbon worms will eat their own bodies if their food supply runs out. They can eat up to 95 percent of themselves and still survive.

IT MAY BE DOUBTED WHETHER THERE ARE ANY OTHER ANIMALS WHICH HAVE PLAYED SO IMPORTANT A PART IN THE HISTORY OF THE WORLD, AS HAVE THESE LOWLY CREATURES.

CHARLES DARWIN

Lewis Carroll said he liked worms “because nobody else does” but Charles Darwin was also a huge admirer. He spent days counting earthworms in his garden while his son played the bassoon to them. There are three thousand species of earthworm, ranging from two inches to eleven feet long. Good soil contains a million earthworms per acre. A typical earthworm has no lungs, teeth, or eyes but it has ten hearts, arranged in five pairs. Though they are eyeless, their skin detects changes in light. Their simple brains are used merely to tell their bodies how to react to these changes. If you removed an earthworm’s brain, you wouldn’t notice much change in its behavior. The sex organs of an earthworm are located in the clitellum, the bulge a third of the way from the front of the worm that looks like a rubbery armband. The word is from the Latin clitellae, a packsaddle. Earthworms mate by lying next to each other, head to tail. Both secrete mucus until each is enclosed in a slime tube, after which they exchange sperm and eggs. Earthworms are essential to life, because they aerate the soil, enabling plants to grow—without them, we’d all starve in short order. Cleopatra declared earthworms sacred: removing one from Egypt was an offense punishable by death. It’s still legal to play the bassoon to them, however.

THE MODEL WORM

The nematode worm, Caenorhabditis elegans, is one of the simplest of all animals and probably the most thoroughly studied. It was the first animal to have its genome sequenced.

It also likes nicotine and suffers terrible withdrawal symptoms once addicted.

“Hey, I thought you’d given up.”

“I have—these are for research.”

TAILPIECE

The philosopher William James once wrote that a crab would be “filled with a sense of personal outrage” if it could hear us class it as a crustacean. “I am no such thing,” it would say. “I am MYSELF, MYSELF alone.” With that in mind, we’d like to be able to declare that no animal has been intentionally insulted, misrepresented, or traduced in the making of this book.

It is the product of much research by many people, but the core team, led by zookeeper-turned-astrophysicist Chris Gray, were James “Eggshaped” Harkin, Mat Coward, Jenny Doughty, Molly Oldfield, and Justin Gayner. The only reason no sources are listed is aesthetic—it would make this book look and feel like a very different kind of book. If you would like to check, correct, or add to the information we have gathered, we would love to hear from you at www.qi.com/animalignorance.

All mistakes are our own; all the best information has come from real scientists like Dr. Joseph Garner at Purdue University, or the indefatigable efforts of the QI Elves. Special mention must go to Piers Fletcher, Justin Pollard, Garrick Alder, Xander Cansell, Vitali Vitaliev, and to the regular members of the QI Talkboard who operate like an intellectual SWAT team, always on hand with original research and wise advice. Particular thanks are due to suze and dr. bob.

We’d also like to thank Stephen Page, Julian Loose, David Watkins, and the team at Faber for their faith and patience; Paula Turner for her keen editorial eye and linguistic sure-footedness; and Sarah Chaloner, Beatrice Gray, and Lorraine Heggessy at Talkback ThamesTV: this isn’t much of a TV tie-in, but they helped make the space in which it was written.

Finally, thanks to Rachael, Sarah, and Helen who have listened, advised, foraged, nurtured, and generally kept the kinship groups going while we hunted.

ALL THE THOUGHTS OF A TURTLE ARE TURTLE.

RALPH WALDO EMERSON

ALSO BY JOHN MITCHINSON AND JOHN LLOYD

The Book of General Ignorance

ALSO BY JOHN LLOYD (WITH DOUGLAS ADAMS)

The Meaning of Liff

The Deeper Meaning of Liff

Also by JOHN LLOYD and JOHN MITCHINSON

“Trivia buffs and know-it-alls alike will exult to find so much repeatable wisdom gathered in one place.”

—NEW YORK TIMES

The Book of General Ignorance
Everything You Think You Know Is Wrong
978-0-307-39491-0
$19.95 hardcover

Think Magellan was the first man to circumnavigate the globe, baseball was invented in America, Henry VIII had six wives, Mount Everest is the tallest mountain? Wrong, wrong, wrong, and wrong again. Challenging what most of us assume to be verifiable truths in areas like history, literature, science, nature, and more, The Book of General Ignorance is a witty “gotcha” compendium of how little we actually know.

HARMONY BOOKS  NEW YORK

AVAILABLE WHEREVER BOOKS ARE SOLD
WWW.CROWNPUBLISHING.COM

Copyright ©2007 by QI Ltd.
Illustrations copyright ©2007 by Ted Dewan

All rights reserved.
Published in the United States by Harmony Books, an imprint of the Crown Publishing Group, a division of Random House, Inc., New York. www.crownpublishing.com

HARMONY BOOKS is a registered trademark and the Harmony Books colophon is a trademark of Random House, Inc.

Originally published in Great Britain by Faber and Faber Limited, London, in 2007.

Library of Congress Cataloging-in-Publication Data

Mitchinson, John, 1963–
The book of animal ignorance / John Mitchinson and John Lloyd.—1st ed.
p. cm.
1. Animals—Miscellanea.  I. Lloyd, John, 1951–  II. Title.
QL50.M57 2007
590—dc22        2008005125

eISBN: 978-0-307-44991-7

Clipart images courtesy of Clipart ETC, an online service from Florida’s Educational Technology Clearinghouse, http://etc.usf.edu/clipart, and The Pepin Press.

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Table of Contents

C OVER P AGE

T ITLE P AGE

F OREWORD | Stephen Fry

I NTRODUCTION | John Mitchinson and John Lloyd

Aardvark

Albatross

Anglerfish

Ant

Armadillo

Badger

Bat

Bear

Beaver

Bee

Beetle

Binturong

Bison

Box Jellyfish

Butterfly

Cane Toad

Capercaillie

Cat

Catfish

Cheetah

Chimpanzee

Cicada

Comb Jelly

Coral

Cow

Crane

Dog

Dolphin

Donkey

Eagle

Echidna

Eel

Elephant

Ferret

Flea

Fly

Fossa

Fox

Frog

Giant Tortoise

Gibbon

Giraffe

Goat

Goose

Gorilla

Hedgehog

Hoatzin

Horse

Human

Hummingbird

Hyena

Kangaroo

Koala

Komodo Dragon

Leech

Lion

Lizard

Lobster

Louse

Mite

Mole

Monkey

Moose

Mouse

Naked Mole Rat

Octopus

Owl

Pangolin

Parrot

Pearl Oyster

Penguin

Pig

Pigeon

Platypus

Porcupine

Quoll

Rabbit

Raccoon

Rat

Salamander

Scorpion

Sea Cow

Sea Cucumber

Seal

Shark

Sheep

Snake

Spider

Starfish

Tapir

Tardigrade

Termite

Toad

Tuatara

Walrus

Wasp

Whale

Woodlouse

Woodpecker

Worm

T AILPIECE

A LSO BY J OHN M ITCHINSON AND J OHN L LOYD

P REVIEW

C OPYRIGHT