He doubted people could have survived (they would have been eaten) in North America until about 13,000 to 15,000 years ago—or whenever the man-eaters went extinct.
Furthermore, Geist notes that not only were those predators huge, but the fossil record reveals many more specimens with significantly healed broken bones and damaged teeth than seen in modern carnivores or African species. He believes this means that the predators really had to fight hard to bring down their huge and formidable prey, that the cats and bears were perpetually hungry and desperate enough to take chances. Also, Geist argues, that the North American prey animals’ “organs of food acquisition and processing remained exceedingly primitive,” so that they remained in low densities and fed on only the best grass. All of which, he believes, indicates the predators were very aggressive.
One might take exception to a generalization or two, but the unmistakable point is that some experts think that Pleistocene predators precluded human colonization of the Americas until just about Clovis times. Geist thinks that the North American mega-fauna, both carnivores and herbivores, impeded human movements in two ways. The grazers created fire-resistant plant mosaics, reducing fuel buildup so that lightning produced only small fires. Humans couldn’t just torch the landscape, like they probably did in Australia, and the great carnivores, the argument goes, used the pilgrims as food. Much blame is heaped at the huge paws of Arctodus simus, the short-faced bear.
Early Americans would have had to live with several gigantic predators, among them sabertooth cats, lions, wolves, huge cheetahs—no doubt the fastest predator on earth—and the short-faced bear. Could people have survived at all and, if they did, would those pockets of early humans have been hunted into extinction by predators, leaving little or no material record of their passing? Or of their genes?
How was it possible to live in the same valleys with this American megafauna? In addition to the short-faced bear, a number of other Pleistocene predators could have been a daily menace to these ice-age hunters. Anyone living in Beringia would have run into lions of the Panthera genus (the African variety but twice as big) who probably hunted in social groups. Wolves, bears and wolverines looking for an easy meal would closely follow the feline hunters.
The abundance of gigantic Pleistocene predators means a lot of killing was going on. There must have been intense competition and interaction around the carcasses of big herbivores. Short-faced bears would have challenged lions and sabertooth cats, with dire and Beringian wolves close behind, shadowed by flocks of ravens, magpies, mobs of buzzards and condors. Grizzlies were around too; probably the entire time humans may have lived in Beringia despite a gap in their fossil record from about 35,000 to 21,000 years ago, which could be attributed to a sampling bias (see Chapter 5).
With humans in Pleistocene America, what was the pecking order? Even if people managed to kill a mammoth or sloth, those other scavenging animals would be close on the scene, especially short-faced bears. And other bears might be in the chase, though not as aggressively as the short-faced variety. Brown bears, over millennia, had learned to defer to humans, even before European firearms arrived, as told in the ethnologies of Western tribes. Early people hunted in groups, growling or roaring when advantageous; grizzlies have never been known to attack a group of four or more people (a technical exception was recorded in July 2011; seven students walking along an Alaskan river trail panicked and ran when they saw a grizzly).
Archaeologists seldom speculate about how people might have fared in such toothy neighborhoods; reasons include not only a general lack of direct evidence but also a pervasive modern ignorance about living with wild animals. North America was not like Africa where early humans and big cats evolved together—no surprises—over a span of two million years. Our hominoid ability to stand up to large predators on the savanna, even before our brain size doubled, is what paved the way for human dispersal out of Africa into the treeless north where many of the final evolutionary brush strokes to the modern mind were applied, preparing Homo sapiens for entry into the New World. With a large hole in the archaeological record, Beringian experts sometimes rely upon academic models of foraging for rates of human colonization.
But the first Americans encountered huge flesh-eating beasts they had never seen before, or had never seen them—unique conditions in human foraging. What might be the possibilities of sharing the landscape with Arctodus simus? The evidence is indirect. Did the gigantic short-faced bear, a long-legged animal that stood almost seven feet at the shoulder, limit human occupation of North America? Paleontologists and anthropological models hardly ever mention people/short-faced bear relations, though it is entirely possible that human demographics in North America could have been severely restricted by the presence of these huge carnivores.
The fact is that ice-age pioneers somehow did co-exist with some of these animals in Siberia between 13,000 and 30,000 years ago; credible pre-Clovis dates from the New World suggest that a few travelers in the lower states of the U.S. did as well. The real mystery is why don’t we find evidence of many more people soaking up the sun south of the North American glacial sheets prior to the Clovis invasion?
To state it clearly, both sides of Beringia—the Siberian and Alaskan, the Old World and the New—may have presented quite different comfort zones for human colonizers. The presence of aggressive American predators in eastern Beringia, especially the short-faced bear, may refute Arctic foraging models for the whole of Beringia.
An illustration of that dissimilarity may be seen in the behavior of the brown bear.
The Eurasian brown bear and the American grizzly may look alike but their aggression levels are sufficiently dissimilar to earn the grizzly the subspecies name, Ursus arctos horribilis. When the brown bear crossed over the Bering Strait some 70,000 years ago to the American side, the theory goes, mothers had to protect their cubs from American lions, short-faced bears, wolves and other Alaskan predators on the open tundra. The best defense was a good offense. Grizzlies charged and, when necessary, attacked threats to their young.
It might be informative to examine the possibility that Pleistocene North America might have been an unusually rough place to live. The presence of all those predators could have squeezed human consciousness into a tight focus that could shed light on the astounding and explosive nature of American colonization around 13,000 years ago.
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A seminal moment in the life of a hunter arrives when he finds himself the hunted: That dread second when he is frozen in his tracks at the edge of the meadow by the eerie silence in the forest; he feels a primordial but familiar tenseness clamping the back of his neck and he realizes that he is being stalked as prey by a large beast.
This ancient relationship doesn’t present itself to the modern world as frequently as it did prior to the industrial age or, especially, during the last days of the Pleistocene. In fact, predation on human beings is so uncommon today that when a single lion, bear or tiger emerges from the bush to stalk, kill and sometimes eat a human it generates international news and best-selling books. A much-chronicled modern account tells the story of a Siberian tiger’s vengeful attack on a man named Markov, a poacher who had previously hunted and wounded the huge cat. The vendetta took place during December of 1997 near the Amba River in the Bikin River drainage of Russia’s Far East. This predatory tiger incident was first chronicled in 1998 by renowned Russian bear and tiger biologist Dmitri Pikunov; the details of this particular attack, however, constituted such a good story that they were rewritten into a popular book in 2010.
The author of Tiger provides a few details of the attack: “In 1997, the Russian investigating officer who was tracking the tiger, reported: ‘(he) had never seen a fellow human so thoroughly and gruesomely annihilated. It looks at first like a heap of laundry until one sees the boots, luminous stubs of broken bone protruding from the tops, the tattered shirt with an arm still fitted to one of the sleeves. Here, amid the twigs and leaf litter in the deep Russian forest, not far from his small cabin, is all that remains of Vladimir Ilyich Markov.’ The
