by Ted Dewan
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 cup-like shelter for each polyp to hide in and keeps them moving upwards towards 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 twice the size of the UK.
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 colours, and produce most of their energy by photosynthesising 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.
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.
A FAMILY GROUP
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 theorised (correctly) that atolls were formed by undersea volcanoes slowly sinking under the surface of the ocean, leaving the ring of coral still growing upwards towards 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, 6,000 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 which 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 per cent of worldwide greenhouse gas emissions and a third of the UK’s. Livestock farming in general creates 18 per cent 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 1,300 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.
MILK AND METHANE MACHINE
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 earache. Hippolyte Mege-Mouries 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 which divides the nostrils) is made into a drug for arthritis. Their blood is made into glue, fertiliser 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 2-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 descendents of the earliest-known birds, whose fossils date back to the early Eocene, over 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, in Wisconsin International Crane Centre. 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.
THE CRANE HORN
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 over 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.
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’.
There is evidence for imitative human crane dances from as early as 7,000 BC. 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.
Cranes have also left their trace in languag
e. 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 twenty but has since recovered to over 450. The breeding programme involves ‘isolation rearing’, where crane eggs are hatched and reared using hand puppets, humans in crane-costumes and taped calls.
Cranes were once widespread in Britain – almost every county has a Cranwell, Cranbourne, Cranley or a 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 – grey wolves are their closest living relatives – and were first kept by humans between 12,000 and 14,000 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 favoured those with milder temperaments. The famous breeding experiment by Russian scientist Dmitri Belyaev in the 1950s 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 400 breeds of domestic dog but all belong to the same species: Canis familiaris. In theory, a 2-pound Chihuahua only a couple of inches high can mate with a Great Dane more than 3 feet tall or a 150-pound St 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. Specialised hunting skills were especially sought after. Springer spaniels have the ability to ‘spring’, or startle, game. The dachshund’s sausage-like 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 noblewomen to keep them warm.
A DOG’S LIFE
There’s no question about it: unlike cats, dogs are useful. A dog’s nose has 220 million olfactory cells, humans a mere five 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 odour-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 per cent of lung cancer sufferers and 88 per cent 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 favours. The wilder shores of hippy 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 undermine 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).
A dolphin’s skin is shed and replaced every two hours to maximise streamlining.
Take echo-location, 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 non-stop), don’t stand a chance.
Their ‘language’ skills are more difficult to assess. Dolphins are famously talkative – despite having no vocal chords. The clicks, whistles, groans, squeals and barks all come from sacs in their nasal passages – as many as 1,200 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 round. The whistle signals show that they communicate, but they are a long swim away from being a language.
Dolphin play is highly complex, and they learn fast. They have a striking ability to follow extraordinarily complicated human commands, and can recognise 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 practise 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 ‘mis-directed sexual behaviour’ with buoys and boats as well as humans. Given that an average male bottlenose weighs 40 stone 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.
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, revelling in the fact that they are where they belong, doing what they do best.
NOSE SONAR
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 6,000 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 per cent of their body weight without complaint opened up the ancient world.
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 grey.
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 their 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 offspring of a male donkey and a female horse is called a hinny. Zebras crossed with donkeys are called zeebrasses and zonkeys. Only 1 in 10,000 of these hybrids are fertile.
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
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.