Monday, October 31, 2016

Ancient enemies: man-killers of prehistory



Happy Halloween, readers! The human psyche is full of fear. A lot of fear comes from our vivid imaginations-horror is full of hypothetical situations based on pure fantasy, but on premises that date to real situations and concepts. Murder, disaster, accident, disease-people die from horrific causes. Most monsters are humanoid-people are the leading cause of human deaths. Many of our fears come from animals. Bats are alien-looking, rats carry disease, and arthropods are alien-looking and often dangerous. 

Then there’s the fears dating from actual experiences. History is replete with examples of people by accident or malice coming into conflict with animals.  People have been killed by our own domesticated animals: dogs can be taught to be brutal attackers, and angry cattle, horses, and pigs are more than a match for an unarmed human.  

Then there’s people being killed by wild animals; every day an unlucky person runs into a dangerous animal, are perceived as predator or prey, and dispatched by deadly natural weapons honed by generations of natural selection.  Without technology, a human being is pathetic. We’re bigger than most animals, but the largest predators dwarf us. Our resistance against venom and chemical weapons is just our size alone. Our natural weapons are pathetic: we can barely outrun an elephant on a good day, our strength is feeble, our teeth are small, and our fingers and toes are tipped with sensitive pads instead of hooves or claws. We have no armor or horns or quills, we can’t fly, and are only efficient swimmers with a great deal of effort. 

Now imagine humans without our technology.  No guns,  not even a spear. We were prey.  An enemy could come at any direction, and kill us without a fight. At night, we were blind without fire, at the mercy of nocturnal predators. You could wake up at any morning and you could find a member of your family vanished. In the day, you’d be looking at the grass nervously. Every time you tried to eat or drink you would have to keep your eyes moving and eating as quickly as possible. If you scavenged from a kill, you could easily find yourself the neighboring carcass.  These are the animals we feared. Welcome to my nightmare, my friends; I think you’re going to like it. 

One of the greatest hominin fossils ever found was of Australopithecus africanus, found in Taung, South Africa. In 1924 Raymond Dart found what he first thought was a monkey skull (he was the only scientist of his time to think it could be a human ancestor, as the racist paradigm of the day refused to consider an African ancestry). Further finds proved, however, that it was a 3-year-old child of a plains ape, one confirmed by Leakey and Johannson to be an upright walking ape that was the closest to our own species., possibly even a direct ancestor.  The child was an amazing find as the skull was attached to a fossilized brain, a proportionally large brain (leading to the mistaken assumption that Australopithecus had a larger brain than other apes, but that turned out to be debunked later). The face was scratched and scarred, and many assumed it was a leopard that killed the baby (a reasonable assumption)


It was in 2006 that Dr.s Lee Berger and Ron Clarke, experts in South African paleontology, realized who killed the child. The specimen was amongst the remains of other small animals, all partially dissembled. The marks on the face were compared to modern primates killed by predators, and the best fit was the Crowned Eagle.

The Crowned Eagle is among the largest African raptors, with the females having known to have 6 foot wingspans and weight 10 lbs, armed with 3 inch (or even larger) talons on muscular feet. They drop from the trees on nearby prey, crushing them in their talons as they pin the prey to the ground. They hunt prey as large as 70 lb bushbuck, breaking their backs and skulls with their talons.  Verreaux’s eagle is larger, but is a hyrax specialist. The Martial Eagle is the largest raptor of Africa, hunting much of the same prey, and cannot be excluded as a possible culprit.   Both eagles have been hunted by the peoples of Africa for killing goats, sheep, and even their children.  No doubt the plains apes of Africa, humans and our ancestors and kin, were on their menu. Even adults would be vulnerable to attack by these deadly raptors.

Leaving Africa meant leaving these eagles, but their equivalent is the Golden Eagle, an incredibly successful raptor that specializes in killing mammals. The females of this iconic predator can grow up to 15 lbs with 7 foot wingspans. While pheasants, rabbits, and ground squirrels make up the bulk of their diet, they can bring down 40 lb fawns and sheep. While not as dangerous as the African eagles, human children today are still warned to be wary of these birds. They can exert 600 lbs per square inch on their claws, enough to crush vertebra like celery, and Central Asians raise them to hunt the wolves that prey on their herds.   


In South America, modern humans encountered the legendary harpy eagle, and in the Philippines the rare superpredator Monkey-Eating eagle. However, it is in New Zealand that we’ve met our most deadly avian predator. When the first Maori arrived on the islands, they found the giant moa birds to be excellent prey, and hunted them to extinction. However, they also encountered the moa’s previous predator: Harpagornis. Weighing over 30 lbs, it was a moa specialist. The Maori forever remembered it as the Te Hokioi, or Te Poukai, father of all birds, a man eating monster of the mountains. It’s possible that this giant predator inspired the legendary monster Kurangaituku, a bird woman slain by the heroic Hatupatu.  Moas weighed more than 500 lbs, but the fossils show that this giant eagle could slay them. If a human was caught unaware or unarmed, they would be easy prey. It’s easy to believe that the Maari deliberately hunted them to extinction to keep their families safe as well as in competition for moa.

Of course, crowned and martial eagles eat monkeys. So do other arboreal predators like pythons.  Millions of humans are horrified of snakes, and for very good reason. The rock python is the largest snake in Africa, over 10 feet long and 100 lbs, but specimens have been recorded being twice as large. Like crowned eagles, they hunt small antelope and have been recorded attempting to kill children. Just like the eagles, they eat monkeys in the forests and plains of Africa, and could have done so with the young and small ancestors of our species.  Snakes are masters of stealth, waiting for days for food to walk into their path.  Pythons certainly ate our ancestors, and perhaps even Australopithecus could have fallen prey to them. 

This fear of snakes is reinforced by much deadlier snakes armed with venom. They strike people in self defense, usually putting up a threat display before striking. Unlike pythons, however, their bites are lethal and the snakes would rather follow their bluff with a deadly sting than flight.  Africa is full of venomous snakes, the most famous being the black mama. Fortunately, it’s reclusive and more prone to flight than to use its venom. Unfortunately, when it does bite, it injects 100 mg of neurotoxins and cardiotoxins into the target. The symptoms are swift-headache, pain, numbness and tingling from the nerves being attacked, then sweating and mouth-watering as the body’s system struggles. Finally, in less than 45 minutes in an adult human, the body goes into shock as the venom hits the heart and spine, causing paralysis and usually death in a matter of hours.

The puff adder is far more dangerous, ironically. It’s found in all parts of Africa outside the deserts and jungles, ventures into urban areas, and usually follows its bluff with attack. The strike is the last line of defense after camouflage and a menacing hiss, but its deadly and aggressive. In captivity they are antagonistic and angry, always puffing and striking when approached.  Its bite contains 300 mg of cytotoxin, a horrifying poison.  It sets in with a decline in blood pressure, bruising, vomiting, blistering, and pain, then turns to necrosis, killing off the cells in the body. If left untreated, the necrosis spreads, killing off limbs, inducing gangrene, and the victim dies of blood loss. 100 mg of the toxin can kill an adult man in 25 hours. 
 

Of course, the most famous of venomous snakes are the cobras, and the first humans shared their world with three species of spitting cobra, the forest cobra, and the Egyptian cobra. Spitting is not lethal, but it does blind the victim, and the bites of spitting cobras contain both cytotoxins and neurotoxins. The forest and Egyptian cobras are large animals, 7 to 10 feet long, so their venom is powerful to take on larger prey. Like their spitting kin, their venom attacks both cells and nerves, leading in paralysis, necrosis, and death in hours if left untreated. The unwary or curious hominin that accidentally antagonized these snakes paid with their lives, as such people in rural East Africa do today.  As humans moved into Asia, they would not only meet more horrific vipers and cobras but Krait and Taipan. In India alone, gigantic King Cobras, cosmopolitan Spectacled Cobras, fierce Sawscale and Russel’s vipers, and the tenacious nocturne the Common Krait. While endangered now, they’re still formidable animals and must be given a wide berth 

The deadliest of all reptiles, however, are the crocodiles. Every animal has to drink, and the water is the home of these powerful archosaurs.  Three species, only one of which is still extant, ruled African rivers. The oldest was Rimasuchus or Lloyd’s Rift Crocodile, appearing in the Miocene and surviving into the early Pleistocene. 7 meters long, their bites are distinguished by their sheer size of the marks on mammal bones. In addition to young rhinoceri, ungulates, and infant proboscideans, primates were fair prey, and their teeth have left many a mark on human bones from Australopithecus to even Homo erectus. 

 Rimasuchus was overthrown in the Pliocene by two species of the genus Crocodylus. The largest was the horned, 25-foot monster Crocodylus anthropophagus, named for being found in Olduvai Gorge, where many hominin and human fossils have been found. No doubt it would have found us easy prey, striking from the water and killing the victim before anyone knew what was happening, before any alarms could be sounded. Thankfully, the ice ages dried up the Rift Valley, ending both the old Rift Crocodile and its horned usurper. 

However, Australopithecus would have also been preyed on not only by the giants above, but by a predator that still haunts African waterways.  Nile Crocodiles are everywhere,  eating anything they can catch. They range from the common 10 to the rare but documented 20 feet (such as the legendary 1-ton septuagenarian man-eater Gustave) in length, eating prey from small fish and turtles to giraffes, buffalo, and eland. There’s even one incident where foolhardy black rhinoceros tried to swim through deep water and fell prey to a huge crocodile. If a lion, even a large male, is foolish enough to probe croc-infested waters, he will die.  The still-more-horrifying water pollution and the leather industry have taken their toll on the crocs, but in protected areas they thrive.  The wide range of Nile crocs leads to 12 reported deaths a year even in the 21st century.  

Death by crocodile is swift. The moment a prey wades or even walks to the water’s edge, they are in striking distance. The crocodile strikes at 20 miles an hour from total submersion, its powerful tail launching it at the target. Once the opened mouth hits the target, it clamps down 60 2-inch teeth at 5000 PSI, enough to break a cow’s limb.  If the croc hits the muzzle, it will pull the victim into the water to drown (a human skull would just pop, though). If it bites a limb, it will pull it in to the water then roll its entire body to twist the limb off. Usually death from blood loss and drowning finish the prey off.  Baboons and apes in Africa often refuse to cross water, and it’s unknown when our species learned to overcome that fear. Even a man with a high-powered rifle is in danger if he gets too close or is shooting from a boat-the armor and strong skull can withstand bullets in certain circumstances.
What else do apes and monkeys fear? They fear the night. Why do we fear the night, the darkness? For one thing, our color vision prevents us from having effective night vision, rendering us nearly blind. And that’s when we’re prey for leopards. Take your house cat-they can see at night, have incredible agility and senses of smell, and can land a nasty scratch or bite if irritated. 


Leopards are not cute little kittens for long.  Male leopards can reach 200 lbs and run at 35 miles per hour. Adult male baboons and apes are more than a match for them in the day, but when night falls, they are targets. Leopards have excellent night vision, and incredible muscular control and precision. They quietly stalk the prey, get as close as possible, then in a powerful leap, throttle them with their powerful jaws. Animals often wake up to find one of their own missing, only to later see their remains yanked up a tree. The biggest leopards can kill a one-ton eland, and pull up 300 lb wildebeest into their tree or cave. Primates make good prey for them due to being helpless at night.
Worst of all, leopards are cosmopolitan, being found in all continents (the European leopard and Jaguar were wiped out by the ice age) but Australia and the Americas (the Americans have pumas and jaguars filling in their niche). 


  For 6 million years they’ve made short work of primates from Orroin and Paranthropus on the plains of Africa to modern humans in rural Africa and India.  Some leopards in history have become so assured to be able to hunt humans they even attack during the day.  One leopard in India, the Panar Leopard of 1910, killed and devoured over 400 people before the  legendary Anglo-Indian hunter/conservationist Jim Corbett  brought him down.  In the spring of 2015, at least 10 people were killed by leopards across India. In turn, traditional medicine and the growth of human populations in Africa and Asia have ravaged leopard populations in turn.
You see, as human populations expand, they push into leopard ranges. Worse, they destroy habitat for their herds. With sheep, goats, and cattle replacing the native fauna, the versatile and cunning cats turn on the domestic animals as prey, and sometimes find humans as side-courses. Even worse are the man eaters, older, sicker cats, unable to tackle prey or confront other leopards for territory, hunting people as easy prey and their main food source. 

Lions and tigers, being larger but diurnal, do more damage to humans but are in turn critically endangered due to their food and territorial needs. Lions evolved in Africa about 1 million years ago, spread into Eurasia and North America, then quickly became almost extinct over the past 200,000 years of constant conflict with humans. Preindustrial societies waged war with predator cats over territory and prey, and industrial cultures hunt them for trophies and superstition to the point of extinction. 

The genus Panthera, the endangered genus of big cats, was not the first cat predator on apes, of course.  About 10 million years ago the main predator in Eurasia, Africa, and North America was Machairodus. Joined with its kin Amphimachairodus and Miomachairodus, this tiger-sized giant (from 600 to 1,000 lbs) evolved long serrated fangs for killing giant prey. It’s possible that these cats caused the last of the creodonts, nimravids and bear dogs to go extinct.  Machairodus was succeeded in the Pliocene by the smaller (300 lb) sabertooth Megantereon, who covered the same territories alongside the ungulate-specialist cousin Dinofeis

Megantereon was definitely an ape hunter. Large fangmarks have been found on the bones of Australopithecus and Paranthropus, and even our own genus was prey. A Homo erectus specimen from Georgia, D2280, was found with deep, partially healed, probably mortal wounds on its forehead, wounds that match the fangs of this cat. Isotopes taken from the teeth of Megantereon have been analyzed, and it seems that the animal had the same range of prey as leopards do today, including primates.  No doubt countless unwary hominins have been taken as prey by this sabertooth cat. 

Interestingly enough, the fossil site of Zhoukoudien has both remains of Homo erectus and Megantereon, some of the last fossils of either species. One can imagine a dark night in northern China, these prehistoric humans clutched at their wooden spears and huddled around their cookfire,  shivering at the howl of the wolf, the cackle of the hyena, and the knowledge that somewhere in the dark, a saber-tooth monster could grab them from behind and drag them into the darkness, a darkness that lasted forever for the victim. 

Zhokoudian was also a site for the most horrifying hyena of all time. Hyenas evolved as the equivalent of dogs in the old world during the Miocene, sophisticated pack hunters that could take a variety of different prey. Spotted hyenas, the largest and most successful of the family, ranged into Eurasia during the Pliocene and the Pleistocene, their bone-crushing bites leaving their mark on hominin fossils through the ages.  Today they are feared as grave-robbers and the familiars and forms of witches in Africa, and horror stories are told of the horrific civil wars of the 20th century providing bounties for the hyenas. To make matters worse, spotted hyenas, unlike the smaller brown and striped species, are incredible hunters, and like leopards hunt at night. They’re not as audacious or cosmopolitan as leopards, so they have killed fewer people, but hyena attacks have happened and do happen every couple of years. Unlike leopards, they prefer ungulates and are more likely to take livestock, but a century ago villages were reported as being terrorized by packs of starving hyenas.

The Spotted Hyena is not the only man-eating hyena in prehistory however. Until 300,000 years ago, the spotted species shared its range across Africa and Eurasia with the giant hyena, Pachycrocuta. This animal could grow the size of a lioness, weigh 300 lbs, and their lairs are filled with the bones of their prey.  If these animals could bring down cattle and bison, they could bring down humans. You see, its size made it a less efficient hunter than the spotted species, as the latter was smaller and could support larger families and run faster. It’s been speculated that the giant hyena was more of a scavenger, using its size to dominate spotted hyenas, wolves, and leopards, even confronting sabertooth cats. On one hand, the bite of the giant hyena is stronger at the molars than canines, preventing a stronger killing bite, and some papers insist on an exclusively scavenger lifestyle. On the other, the body is also more robust, not just the molars-spotted hyenas have stronger bones than their scavenging kin, which need to move quickly to grab prey. There is also the fact that its eyes give it stereoscopic vision-if it was a scavenger, it was not that efficient a scavenger, moving slower, specializing in large carcasses, and not having the same breadth of vision of a vulture. Vultures and striped hyenas are poor analogues for large terrestrial carnivores.  At any rate, slower animals like humans would be possible prey. 

Sure enough, Zhokoudian contains not only human caves, but hyena caves as well. Human skulls and long bones at the site have been found to have been crushed. One suggestion is that other humans broke the bones for cannibalism, but it’s just as equally possible that the bones were crushed by the teeth of hyenas. Spotted hyenas have a bite force of over 1,000 lbs per square inch, and the larger hyena would have a stronger bite. Finds in Georgia and Spain show elephant carcasses fed on by these hyenas, suggesting that the animal could at least pierce the bones of an elephant. Assuming the females reach twice the size of spotted hyena females, and that bite force scales up by size, that would mean hyena girls with 2,000 lb bites! Enough to pop a human skull like an egg or snap a femur like a twig.  
 
Finally, a universal object of awe in the northern continents is the bear. Every year in North America, a person living in bear country is killed by a bear. There are two reasons for bear attacks-one is by females pretending their cubs that that human unknowingly (And sometimes knowingly) approach, and the other is predation. Bears are omnivores, eating anything it comes across-fruit, fish, roots, leaves, eggs, carrion, reptiles and whatever mammals it can barrel down. Brown bears are the most successful species, having adapted to a historical range from Morocco and Spain to Mexico. Smaller black bears live in China and North America. In northern China, black bears and brown bears neighbor pandas. In India, their range borders that of sloth bears and sun bears. Around the arctic circle, they border Polar bears. And in South America, they are not found but instead bears are of the Spectacled species.  In the Americas, two genera of giant short faced bears ranged from Argentina to Alaska until the invasion of humans. 

Bear art adorns European human sites. Neanderthal sites contain bear bones, and cave bear skulls were collected by Neanderthal people in some areas, perhaps as a form of worship.  Bears and humans, being voracious omnivores, often find themselves at war through history. Bears have been hunted to extinction in many parts of the range, such as North Africa and Mexico.  Extinct Pleistocene bears  like cave bears and short faced bears were likely hunted to extinction by their human rivals. Polar bears, Spectacled bears, and Sun bears tend to avoid humans due to their habitats, but black bears and brown bears and humans have hunted each other for thousands of years.  Black bears and sloth bears kill people usually in aggressive counterattacks.  The conflict between humans and bears is ancient, but we don’t know who first preyed on who. By the time humans left Africa, we were hunting small game. Did we kill cubs? Did the bears view us as easy prey? The beginning of the conflict, unlike those of humans against big cats, remains a mystery. Asian bears are nearly extinct thanks to human hunting and habitat loss, but American bears are neighbors as Americans and Canadians still live in woody areas where bears once ruled and venture to when other foods are scarce.

I recommend the excellent book Man the Hunted by Donna Hart for more on this topic. We’ll eventually talk about these individual species in their own articles, but it says something how many of our fears- water, the night, reptiles, etc, all date back to a time when we were prey.  Human technology has made us the winner, and our old enemies are almost destroyed by our hunger and greed, but our fears and perceptions are prehistoric. We’ve evolved our cognition; it’s time we evolve our psyche.

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