Crocodiles – Natural histories of extraordinary species that changed our world

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Crocodiles – Natural histories of extraordinary species that changed our world

Admiration and Abhorrence

The ancient Greeks called it Crocodilopolis – the city of the crocodiles – after its inhabitants’ object of obsession. Located in the most fertile region in Egypt, Shedet (present-day Faiyum) was renowned for its corn, vegetables, flowers and olives, and was also the most important centre of the cult of Sobek, the crocodile god. Although they no longer throng its banks, thousands of years ago crocodiles dominated Egyptian history and culture. We know about this today from many sources, such as archaeological finds, documents and hieroglyphics, but most vividly from Herodotus’s Histories. When he visited Crocodilopolis, the Greek historian wrote: ‘The City of Crocodiles is more amazing than the Pyramids. It has twelve covered courtyards surrounded by a huge wall. There are three thousand rooms, half of which are underground. They are built of fine stone and decorated with beautiful figures, and it is hard to believe that men built them.’

Herodotus’s readers were fascinated by his stories about the strange animals they had never seen – in many ways his writings were a precursor to today’s natural history documentaries:

The following are the peculiarities of the crocodile: During the four winter months they eat nothing; they are four-footed, and live indifferently on land or in the water … It has the eyes of a pig, teeth large and tusk-like; it cannot move its under-jaw [Herodotus was wrong – it can], and in this respect too it is singular, being the only animal in the world which moves the upper-jaw but not the under. It has strong claws and a scaly skin, impenetrable upon the back. In the water it is blind, but on land it is very keen of sight … The crocodile is esteemed sacred by some Egyptians, by others he is treated as an enemy.

Sobek was the best-known Egyptian crocodile god. Usually depicted as a man with the head, jaws and teeth of a crocodile, he was closely linked with various creation myths, including the beliefs that he created order in the universe, fashioned the River Nile from his own sweat, and made the land on the banks of the river fertile.

The people of Shedet worshipped a living sacred crocodile, called Petsuchos. Crocodile eggs were incubated in mounds of sand in special nurseries, and the resulting small reptiles were carefully reared in temple ponds. Considered the living incarnation of the god, the crocodiles were decorated with gold and glass jewellery on their heads and bracelets on their forefeet, and fed roasted fish, beef, goose, cakes, milk and wine by the priests. Pilgrims flocked to Sobek’s various temples across Egypt to help feed them and donate food. The behaviour of the animal towards visitors was taken as evidence of how the gods felt. Rank made no difference. The Roman historian Aelian told how when the pharaoh Ptolemy called ‘to the tamest of the crocodiles, it paid him no attention and would not accept the food he offered. The priests realized that the crocodile knew that Ptolemy’s end was approaching.’ Like the pharaohs themselves, when one Petsuchos died, another replaced it.

But like the crocodile, Sobek had a darker side, as evinced in his various alternative names which included ‘pointed of teeth’ and ‘he who loves robbery’. This ambivalence extended to the Egyptians’ treatment of the earthly representatives of Sobek, the crocodiles themselves. Because while these crocodiles were worshipped in Sobek’s temples, elsewhere and nearby they were being hunted down and killed.

The hieroglyph of a crocodile could mean greedy and aggressive, but it also signified command and control. The crocodile was at once admired for its speed, strength and hunting skills; and yet simultaneously reviled and feared. At the time protective crocodile amulets were highly popular. The crocodile’s power to snatch and destroy its prey was thought to be symbolic of the might of the pharaoh – the strength of the reptile being a manifestation of the pharaoh’s own power. The hieroglyphic for ‘sovereign’ was written with two crocodiles and a falcon. After their death, many Egyptian kings were buried along with mummified crocodiles, and sometimes also with crocodile eggs, enabling the dead king to gain Sobek’s protection in the afterlife to come.

Because they were held as holy (along with other species such as cats, ibises and baboons), crocodiles were mummified and buried in special cemeteries when they died. Over 10,000 crocodiles have been found, one more than 5 metres long. One animal was surrounded by fifty tiny crocodiles that had just hatched, possibly its own brood. They were arranged in a little army, marching towards the head of the mummy. Baby crocodiles that had died were sometimes placed within a mummified adult’s mouth, echoing the way mother crocodiles carry their young to the water.

According to Herodotus, even those killed by crocodiles enjoyed a special status:

Whenever any one is found to have been carried off by a crocodile, the people of any city by which he may have been cast up on land must embalm him and lay him out in the fairest way they can and bury him in a sacred burial-place, nor may any of his relations or friends besides touch him, but the priests of the Nile themselves handle the corpse and bury it as that of one who was something more than man.

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In Rudyard Kipling’s much loved Just So Stories, the Elephant’s Child – ‘who was full of “satiable curtiosity”, and that means he asked ever so many questions’ – goes on a quest to find what the crocodile has for dinner. When he reaches the banks of the great grey-green, greasy Limpopo River, all set about with fever-trees, he discovers to his horror that he is the special on today’s menu. Having enlisted the help of the Bi-Coloured-Python-Rock-Snake he manages to escape the crocodile’s clutches; but not before his original short and stumpy nose has been tugged by the reptile into a proper trunk, which to his surprise the Elephant’s Child finds remarkably useful.

Kipling’s sly reptile, tricking the innocent pachyderm into coming close enough to allow him to grab his nose with those fearsome teeth, plays to the classic image we have of crocodiles: awesome (and, against our better judgement, admirable), yet at the same time absolutely terrifying. It is an image that is remarkably consistent. We see it in films such as the 1986 Crocodile Dundee, in which the sharp-witted rogue Mick ‘Crocodile’ Dundee, played by Paul Hogan, becomes famous for wrestling crocodiles, while his bushcraft skills prove even more useful in the urban jungle of New York. The same plot was later played out in real life, when another Australian daredevil, the late Steve Irwin, became ‘The Crocodile Hunter’, reaching a global TV audience of more than 500 million viewers.

Both these fictional and factual depictions portray crocodiles as monsters: cold-blooded killers whose techniques of killing their prey – grabbing the unfortunate victim in their huge jaws and wrestling with them until they drown or bleed to death – are especially horrific. There are numerous examples of unsuspecting bathers and swimmers being snatched and killed by crocodiles, often in shallow waters, close to the shore.

The expression ‘crocodile tears’ – meaning a false display of grief – comes from the ancient belief that crocodiles wept while luring or devouring their prey. Interestingly, recent scientific research has shown that this may have some basis in natural observation. Tears clean and lubricate the eyes and the crocodiles observed ‘crying’ may well have been out of water for quite some time. The image of an apparently remorseless creature such as a crocodile weeping over its victims has caught the imagination of many writers from Plutarch to Churchill. When Shakespeare’s Othello convinces himself that his wife has been unfaithful he declares: ‘If that the earth could teem with woman’s tears, / Each drop she falls would prove a crocodile.’

Yet we admire crocodiles, too. The crocodile is used as the logo for a luxury brand of sports goods (named after the French tennis player René Lacoste, nicknamed ‘the Crocodile’ because of his tenacious playing style). And we admire their longevity: 66 million years ago, when a catastrophic meteor strike wiped out the rest of the earth’s giants, including the dinosaurs, crocodiles somehow survived and, in the absence of competition, went on to flourish. So what exactly are crocodiles, and do they really live up to their perennial image as ruthless, cold-blooded killers?

The sixteen currently recognised species of true crocodile, in the subfamily Crocodylinae, are (mostly) large, semi-aquatic animals found in both freshwater and marine habitats throughout the tropics: from North and South America, through Africa and Asia, to Australasia. Although they look remarkably similar to other crocodilians such as alligators and gharials, they are subtly different, with a more V-shaped snout and a notch in the upper jaw that allows a large tooth to show through when the animal’s mouth is shut. Crocodiles are also generally much more aggressive than their cousins.

Crocodilians are reptiles. Despite this they are more closely related to (and descended from a common ancestor of) birds and dinosaurs than they are to other reptilian groups such as snakes and lizards. Crocodiles share some physical traits with birds, and build nests in which they lay eggs. Their distant ancestors evolved more than 200 million years ago, originally as terrestrial animals, but later adopting a more aquatic lifestyle.

Some of these early crocodilians were fearsome beasts: Deinosuchus, which lived in the rivers of North America some 80 million years ago, grew to 10 metres long, weighed up to 10 tonnes, and may even have preyed on huge dinosaurs such as tyrannosaurs. This compares to the largest extant species – the Australian saltwater crocodile – that can reach a length of over 6 metres and weigh well over a tonne, making it the heaviest living reptile on the planet.

Crocodiles have changed remarkably little over the millennia. For the crocodile is not far short of the perfect predator: it has a long, streamlined body shape, enabling it to swim rapidly, but also to run very fast on land albeit in short bursts only. The Australian freshwater crocodile has been recorded at a speed of 17 kilometres per hour, easily quick enough to catch a panicking human being who strays close to the water’s edge. Their webbed feet allow them to turn speedily in the water to pursue their prey, while like sharks they are able to replace their rows of teeth constantly throughout their lives, to maximise their biting and gripping efficiency.

Although often territorial, they can also be highly social (unlike most reptiles) and – again, unlike other reptiles – very vocal. They do share one characteristic with other reptiles such as tortoises however: crocodiles are generally very long-lived, with some species reaching 60–70 years old, and a few individuals possibly living for a century or more.

Crocodiles have excellent sensory abilities, with very good night vision (they mostly hunt by night), vertical slit-like pupils (like cats), which help to protect their eyes from bright sunshine during daylight hours, and a clear membrane that covers the eye when they are underwater. They have an acute sense of smell, which allows them to locate (or relocate) carcasses of animals in murky water, and good hearing. Their ears, eyes and nostrils are all located at the top of their head, so they can remain almost entirely submerged without compromising their ability to attack. This is a great advantage for these ‘ambush predators’, as they can conserve their energy while floating unseen beneath the surface, before dashing out to grab their unsuspecting victim. This may be a mammal as large as a wildebeest or zebra, or something less substantial such as a bird, fish or amphibian. Crocodiles have catholic tastes, depending mostly on their size.

Once the prey is caught, crocodiles usually kill it by a war of attrition, turning and twisting their victim around in the water (in an action grimly known as the ‘death roll’) until it gives up its fight for life. Then they take their booty down beneath the water and store it until it rots and becomes easier to dismember and eat. Crocodiles’ stomachs are more acidic than that of any other animal, and they are able to digest the hooves, horns and bones of their prey.

Like their distant relatives the birds and dinosaurs, crocodiles reproduce by laying eggs in a nest, which are then guarded by one or both parents until they hatch. The temperature at which the female maintains the eggs is crucial: those incubated at temperatures of 30 degrees Celsius or below mostly hatch into females; between 31 and 32 degrees both males and females are produced, and from 32 to 33 degrees they are mostly males; though at even higher temperatures this reverts to females.

The ancient Egyptians may have been the best-known civilisation to worship crocodiles, but they certainly weren’t the only one. Crocodilians – including alligators – have long been at the centre of many people’s beliefs. The Australian aborigines hunted the enormous freshwater and saltwater crocodiles for food, but also revered them, singing ritual songs and performing dances in their honour, believing that their dead relatives are reincarnated as crocodiles.

Crocodiles have also been worshipped in the West African state of Mauritania, where they are linked with the preservation of precious water resources; while in Papua New Guinea, young men go through a painful initiation ceremony during which a series of shallow cuts are made on their back which, when they heal, resemble the skin of a crocodile. Without going through this ordeal, no boy can be recognised as a man.

Further west, the independence of the new nation of East Timor in 2002 was marked by a renewal of interest in the myth of the island’s creation. The story goes that a small boy rescued a stranded crocodile and returned it to the sea, thus saving its life. The crocodile promised to serve him any time he needed help. Many years later, when the boy grew up, he decided he wanted to see the world, and called on the crocodile to carry him on his back to far-flung places. When it was time for the crocodile to die it turned itself into a beautiful island, where the man and his descendants could live.

Take a look at a map of the island of Timor, and it is easy to see how this myth arose, for its shape is uncannily like that of a crocodile. Unfortunately the story has had one very negative effect: the people of Timor still revere crocodiles, and believe that they will not be harmed by them; as a result, several people are killed each year as they swim in the seas around the island. In more recent years this reverence has lessened, as the presence of crocodiles discourages lucrative tourism.

In the New World, the crocodile’s relatives the alligators and caimans are also at the centre of many ancient beliefs and rituals. The Aztecs of what is now Mexico regarded the caiman as a symbol of the earth as it floated in the waters of the early universe, and they incorporated the creature – known as ‘Cipactli’ – into their complex calendar. The gods Quetzalcoatl and Tezcatlipoca were supposed to have created the earth out of the caiman’s body, after it had bitten off Tezcatlipoca’s foot, which he had used to lure the animal into captivity.

Today, long after most of these ancient beliefs have died out or been forgotten, we still have an ambivalent relationship with these mighty beasts. The stories of crocodile attacks are as feverishly followed as those of sharks. They remain one of the world’s most dangerous animals: although most human deaths go unreported, it is thought that crocodiles in Africa and South East Asia kill hundreds of people each year.

A battle in the Second World War is the unlikely holder of the Guinness World Record for most deaths in a crocodile attack. On 19 February 1945, 900 Japanese soldiers crossed 16 kilometres of Burmese mangrove swamps full of saltwater crocodiles in an abortive attempt to rejoin a larger battalion. Twenty were captured by the British, and almost 500 are known to have escaped; the exact number of deaths is disputed but many of the remainder were probably eaten by the crocodiles. A naturalist with the British troops, Bruce Stanley Wright later wrote a vivid account of it in his 1962 book Wildlife Sketches Near and Far:

That night [of 19 February 1945] was the most horrible that any member of the M.L. [motor launch] crews ever experienced. The scattered rifle shots in the pitch black swamp punctured by the screams of wounded men crushed in the jaws of huge reptiles, and the blurred worrying sound of spinning crocodiles made a cacophony of hell that has rarely been duplicated on earth. At dawn the vultures arrived to clean up what the crocodiles had left.

Being attacked by a crocodile remains one of the most primal human fears to this day. Given that the stories we have come to expect are in the crocodile-wrestling vein of Crocodile Dundee makes this following account all the more interesting. In 1985 the ecophilosopher Val Plumwood was canoeing along a remote lagoon when she encountered a saltwater crocodile. She tried to reach the shore to escape, but the beast was too quick for her, and she was grabbed:

Few of those who have experienced the crocodile’s death roll have lived to describe it. It is, essentially, an experience beyond words of total terror. The crocodile’s breathing and heart metabolism are not suited to prolonged struggle, so the roll is an intense burst of power designed to overcome the victim’s resistance quickly. The crocodile then holds the feebly struggling prey underwater until it drowns. The roll was a centrifuge of boiling blackness that lasted for an eternity, beyond endurance, but when I seemed all but finished, the rolling suddenly stopped. My feet touched bottom, my head broke the surface, and, coughing, I sucked at air, amazed to be alive. The crocodile still had me in its pincer grip between the legs. I had just begun to weep for the prospects of my mangled body when the crocodile pitched me suddenly into a second death roll.

Eventually managing to escape but so badly injured that she had to spend months in intensive care, Plumwood later wrote a fascinating essay about the encounter, called ‘Being Prey’. The rangers who eventually find her assume that the crocodile that attacked her should be destroyed but she is adamant that he should be spared: ‘The story of the crocodile encounter now has, for me, a significance quite the opposite of that conveyed in the master/monster narrative. It is a humbling and cautionary tale about our relationship with the earth, about the need to acknowledge our own animality and ecological vulnerability.’

Even in ancient Egypt where they were seen as semi-divine, crocodiles were hunted for food and for their tough and beautiful hides. But in recent years crocodile farming has become big business. Latest estimates suggest that well over 1 million crocodilians are farmed and killed for their skins each year, the most popular species being the American alligator and Nile crocodile. In the state of Louisiana alone, alligator farming is worth at least $60 million a year.

But maybe when it comes to exploiting crocodiles and alligators we’re missing a trick. Scientists have often been puzzled about one aspect of crocodilian biology: when these animals fight one another in violent and prolonged territorial battles, and often suffer terrible injuries as a result, why do these wounds so rarely become infected?

The answer appears to be in the reptiles’ blood. When tested, the blood of the American alligator has been found to destroy more than twenty different strains of bacteria, including some normally resistant to antibiotics. Even when tested on HIV – the virus that causes AIDS – it depleted the virus by a significant amount. The reason appears to be that the proteins in the blood – known as peptides – help the animals fight off any potentially fatal infections. Now, scientists are hoping to isolate these and create anti-bacterial and anti-viral drugs from them.

So although we may regard crocodiles as some kind of ‘living fossil’, that does them a great injustice. As zoologist and crocodile expert Adam Britton notes, a modern crocodile is closer to a Ferrari than a Model T Ford: both have four wheels, an engine and seats, but one does the job a whole lot better.

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Here too were living flowers

Which like a bud compacted

Their purple cups contracted

And now, in open blossom spread

Stretch’d like green anthers many a seeking head

Robert Southey, ‘The Ancient Sepulchres’

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