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The Lair of the Short-faced Bear

Forbidding Glaciers, Man-eating Predators

and Poisonous Plants in Ice-age America

The great ice fields of the last glacial advance loomed across the entire North American continent and at their maximum around 20,000 years ago constituted an impenetrable barrier to human migration. The glaciers themselves served as barometers to ice-age peoples and when they began to melt about 15,000 years ago they signaled the onset of approaching climate change.

Even today, I note that the question of where the ice is located still resonates in my personal life. In my small world of mountains and wilderness, recognition of the hard face of modern global warming comes in large measure not from reading the pile of scientific research which I receive most every day, but from old friends and some new ones who climb mountains. I am blessed to call among my friends a handful of the world’s great mountain climbers. They climb in British Columbia, Alaska, the Andes, Africa and, most of all, in the Himalayas. My small forays and treks along the Continental Divide of the Northern Rockies and coastal British Columbia are meek in comparison to their expeditions to the high white wilderness of glaciers that mark the roof of the world. But the topic is the same: the disappearance of the world’s glaciers, especially the finite ones we know well and explore like the body of a secret lover.

My own fragile and diminutive mistresses lie along a great traverse of grizzly bear country along the Continental Divide in Montana’s Glacier National Park. The trek starts from the paved road the locals call “Going to the Six-Pack Highway” and departs from all trails as it leads you north towards Canada. It’s not an easy bushwhack and the weather can shut you down. I’ve made the traverse over a half-dozen times beginning forty years ago, often alone or with a trusted friend and, the last, just a few years ago, an abbreviated trip with my own daughter.

As you climb up to the divide and wind around the peaks, Glacier’s famous ice fields come into view. Most are tiny hanging glaciers clinging to the northeast-facing cliffs. A few of the larger ones have names: Vulture, Gyrfalcon or Two Ocean. You walk on snowfields and the tundra of the high country, where you can scarcely put a boot down without stepping on a grizzly dig. You finally scramble your way out of a perfect glacial cirque punctuated with a circular turquoise tarn, using your ice axe here and there for balance and backsliding, and step onto the Continental Divide. It opens up into a narrow expanse of subalpine splendor with stunted fir trees framing chains of shallow mountain lakes. Grizzly sign is everywhere; some of the high meadows look plowed by the long-clawed bears who dig corms and tubers from the thin soil.

Once I followed a well-used animal trail around the shore of small lake up there and almost stumbled into a garbage can-sized dish-shaped depression next to a tree; the grass at the edge of the grizzly daybed sprang upright from the weight of the bear who had just arose from his nap. Considerably more cautious, I crept down the trail. That’s way too close.

In the 1970s, the small glaciers at the head of Valentine Creek still contained blue ice. By the late 1980s, these glaciers had become mere snowfields. Twenty years later, the snow was gone. Now, the ribbon of ice above lonely Gyrfalcon Lake is but a shadow of its hefty parent only thirty-five years ago. On my last traverse of the basin, I climbed up to the hanging glacier and broke off an icicle, sucking the water out of it like a last good kiss.

All this is but a brief moment in a single life watching small, beloved ice-fields shrink and die. A similar tragedy is playing out in the Wind River Range of Wyoming, where large glaciers, though diminished, still flow. My friends tell similar stories of the giant ice fields of the Himalayas. It is a tale of loss, of the end of something beautiful in a melting century.

One can imagine the minds of ice-age explorers dancing with images of glaciers. The first Americans of the Late Pleistocene would not have walked or boated down the icy defiles without a distinct foreboding of approaching change and an appreciation of the coming need for humans to pioneer new habitats, to confront these never-before-seen animals and endure shifting climates.

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The Pleistocene or Great Ice Age lasted about 2 million years (published estimates run from 1.6 to 2.6 million years), during which the northern polar caps surged and ebbed on a cycle of every 100,000 years or so. The last advance, the Wisconsin, started almost a hundred thousand years back in North America and, within that cycle, oscillations in the ice produced smaller advances and retreats. The Late Wisconsin, 12,000 to 38,000 years ago, was generally a time of expanding glaciers that reached their maximums about 20,000 years ago. This period is when humans first show up in North America.

Non-polar glaciers often have their origins in the high country when a cooling climate dumps more snow in the mountains in winter than melts during summer—accumulation exceeds ablation. As the snow builds up over decades and centuries, the pressure causes snow to granulate. The weight of ice compacts the glacier until, like a plastic, it begins to flow downhill. The rivers of mountain glaciers may coalesce and become ice sheets, like the Cordilleran of western North America.

The history of ice in North America is important because it outlines the great mysteries of continental colonization: Who were the first Americans, when and how did they get here and what routes did they take to get south of the ice? Since the archaeological record from the American Late Pleistocene is not robust, reconstruction of ancient environmental habitats contributes substantially to understanding when people could live there. And these habitats depended on where the glaciers were. The ice altered environments and climate. Constantly changing vegetative communities, chewed into a patchwork by the huge Pleistocene grazers and browsers, were the norm. The presence of the great ice sheets carved these plant communities into arrangements for which there are no modern equivalents.

Northern North America probably lay covered by ice during the Last Glacial Maximum (about 18,000 to 20,000 years ago). The Laurentide ice sheet buried the land from the North Atlantic coast to the Rocky Mountain trench, south into Ohio. The Cordilleran ice sheet came out of the Coastal Range and Rocky Mountains, huge valley glaciers coalescing into a composite sheet, smaller than the Laurentide, covering northwestern North America. Temperatures in Greenland during the last glacial maximum were 41 degrees Fahrenheit cooler than today. A key issue for archaeologists is whether there was a corridor between the two sheets sufficiently benign to permit human migrations coming south out of Beringia. Textbook maps often show the two great ice-sheets conjoined. Glacier erratic trains (boulders carried by the glacial ice) on the foothills of the Northern Rockies indicate this was the case 18,000 years ago. But there is conflicting evidence. The Ice Free Corridor (IFC), and other pre-last glacial maximum routes between the ice sheets, could have been open much of the time during the past 30,000 years. The debate continues.

People moved around the edges of these glaciers, looking for food and shelter from the cold. The Greatest Adventure began whenever those bands of Siberian hunters moved east across Beringia into present day Alaska. That crossing could have taken place anytime beginning about 30,000 years ago. The Bering Strait land bridge was almost certainly open 10,000-27,000 years back. Dating for the last stages of the Ice Age is imprecise; the geography of ice in North America, which areas might have been ice-free, is not clear. Many archaeologists believe the far north of Late Pleistocene Siberia was too damn cold for people to live there. Since no sites dating between 30,000 and about 14,000 years ago have been found in northeastern Siberia, some scientists think these children of the ice retreated south to sub-Arctic central Siberia during this time. Similar claims about the inhospitable climate—bleak, frigid, uninhabitable—are made for the same period in Alaska.

Approximate extent of ice during the Last Glacial Maximum.

But even ice-ages have summer time. Just because we haven’t yet found an archaeological trace, that doesn’t mean hunters were not eking out a living in these frigid climes. In fact, plenty of big game, the Pleistocene megafauna, roamed Beringia before and during the Last Glacial Maximum (LGM) when glaciers blocked all routes south; the Arctic, though colder before and during the LGM, was, botanists think, more grassy than shrubby offering an abundance of food for mammoth and other grazers who were in turn stalked through the snows by their gigantic predators.

The fossil record of Alaska and Canada confirms the presence of these animals. Now-extinct species of camel, long-horned bison, tapir, deer, antelope and horse ranged the tundra and grasslands. Great herds of caribou gnawed the northern lichen and bison grazed the open plains. Hidden in the draws and breaks were huge American lions, big dire wolves and gigantic short-faced bears. The deglaciated valleys were wet, the high benches speckled with pothole lakes, springs and ponds frequented by giant beaver. Mastodon browsed the edges of boreal forests; small groups of mammoth roamed the open country.

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A spectacular array of very large animals lived in North America during the Late Pleistocene. Most of this astonishing menagerie of megafauna, along with some smaller genera of creatures, vanished suddenly nearly 13,000 years ago. The bulk of these animals were unusually large. Here’s a sample bestiary:

Most iconic was the Columbian mammoth, monster of the plains, and its smaller cousin (they probably interbred) of the North, the woolly mammoth. Standing several feet taller than the largest elephant ever measured, these grazers no doubt traveled in matriarchal herds, like today’s elephants. Massive, long tusks spiraled to a point and sometimes crossed. These creatures, some believe, were the spiritual and material center of Clovis culture and show up in a dozen kill or butchering sites. A small population of woolly mammoth survived on Alaska’s Wrangell Island until about 4,000 years ago.

The American mastodon was also hunted by Clovis people, but perhaps not as frequently as mammoths. Shorter and stockier than the mammoth, this browser of spruce trees was a solitary animal often found in forests.

Clovis people also hunted a four-tusked cousin of the mastodon, the gomphothere, down in Sonora, Mexico about 13,000 years ago. This elephantine creature was found more commonly in South America and was, prior to the Sonoran discovery, believed to have gone extinct 30,000 years ago in the region.

Several kinds of giant ground sloth roamed the land and ranged in weight from about 200 to 6,000 pounds. The big ones had huge claws and one would think they would draw attention from anyone wandering the grasslands.

Early Americans no doubt hunted other American animals, for which we have no archaeological record of association. Chief among them would be horses, camels, tapir, peccary and, in the North, Saiga antelope.

A gigantic long-horned species of bison roamed the Pleistocene steppes and plains, along with herds of smaller buffalo. Bison, along with caribou and musk ox, important prey animals for Clovis as well as later human hunters, survived the great megafauna extinction around 12,900 years ago.

Smaller animals, but gigantic for their kind, included 350-pound beaver, armadillo and the glyptodont, a mammal almost ten feet long with armored shell, head and tail. Giant carrion birds teetered over the landscape, including condors with 20-foot wingspans. A deer called the stag-moose (slightly larger than a modern moose) displayed some of the biggest palmate antlers ever found on a mammal; these antlers are frequently preserved in fossil deposits. We don’t know anything of the relationships of such creatures with humans but the animals must have painted the Pleistocene landscape with shimmering colors scarcely dreamed of today.

Preying on the grazing and browsing animals were giant carnivores. The biggest was the North American short-faced bear weighing in at over a ton. This long-legged giant could have been an omnivore but others think it lived by exclusive scavenging and predation. More on Arctodus simus later in this chapter.

The most effective American predator might have been the Pleistocene lion, same genus as today’s African variety but eight-feet long with some of the biggest cat craniums ever measured, an animal that prowled North America and northwestern South America. The big brains, some suggest, indicate a highly social, pride-hunting predator.

The prototypical American Ice Age carnivore was the sabertooth cat, a stout, powerful predator with six-inch upper canines. The lovely name, Smilodon fatalis, says it all. This sabertooth was about the size of an African lion and is believed to have been a solitary ambusher of prey. Likewise, the scimitar cat had long, sharp serrated fangs perfect, they say, for slashing baby mammoths. As the second kind of sabertooth, the scimitar’s teeth were nowhere near as long as Smilodon. The American cheetah, twice as big as the one in Africa, was also on the scene.

Wolves functioned much as they do today but probably scavenged more. The dire wolf and Beringian gray wolf had unusually heavy jaws and crushing teeth; the paleontological guess is that they both scavenged and hunted in packs. Dhole dogs, coyote and fox followed the flocks of condors, buzzards, crows and ravens to the kill sites of big cats and, eventually, ice-age Americans.

Los Angeles’s La Brea tar pits hint at the spectrum of Pleistocene predators, unfortunate enough to mire in the tar. The Natural History Museum of Los Angeles lists these numbers: 4,000 dire wolves, 2,000 sabertooths (not scimitar), 80 lions, mostly male, and 30 short-faced bears. It’s theorized that the sabertooths came in for mired bison and dire wolves cleaned up after them. Of course, tar pit death traps are not the same as kill sites: Carnivore behavior and selection (death) might be atypical at La Brea.

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As much as the ice sheets impeded human migratory routes, they also shaped the kind of people they would become. Surviving in the Arctic made the people tough; hunting big game and defending their kills against bears and lions could have infused hunters with edgy audacity and made them bold enough to go after the biggest game, at all costs. Eventually, some experts think, their experience north of the ice and in the ice-free corridors prepared them to hunt the American mammoth, the largest beast of all. This kind of prey required specialized lithic (stone-working) technology and may have spawned the iconic Clovis point. Much ink has been applied to papers debating these topics: Chapter 8 will add some more.

For the earliest American travelers, the ice must have seemed all encompassing, pervading their dreams and chiseling their angular features with blasts of Arctic wind. Coming down any route from Beringia, through icy defiles, the cold beauty of the glaciers would have dominated all landscapes. One could imagine the first Americans consciously aware of the growing, then shrinking glaciers, witnessing the melting white wilderness with a measure of alarm. Along the coast, the rising ocean would have haltingly inundated the forest, inch by inch. Climatic fluctuation, the retreat of the ice and the declining mass of the megafauna were not imperceptible changes to the first American explorers over the years. Beyond the daily struggle to survive, the wind was alive with the palpable scent of the regeneration of the earth—icy winds off the glacial front, the warm chinooks blowing up the Rocky Mountain Front and a wind bearing the fetor of dying beasts. How exciting, how terrifying a time to live: The last days of the Ice Age.

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The wide aim of this book is not so much to sort out the archaeological and other arguments (a great story) about people coming to America in the last days of the Pleistocene, but to inquire how people might have responded, bearing witness to radically changing environmental conditions. Though fundamentally unknowable, the question is worth some speculative consideration. Today, we approach a world we might not recognize by the end of this century. “Global warming”(often softened by the term climate change) is a catchword we can conveniently ignore with our modern technology and cultural insulation. Should our local weather warm up by a few degrees, who cares? But the extremes of global warming—widespread drought, floods, fierce storms, frigid winters in temperate zones and fiery heat—are the big enchiladas of global warming. These intense events can dramatically shift the limits of agriculture, create uninhabitable deserts the size of continents and break down the boundaries of what we call civilization. That this could happen within our lifetime does not seem to sharpen our perception of the threat. The climatic shifts of the Pleistocene might look quite mild in comparison to those of the 21st century.

What does it take to see the shadow of the sabertooth in the present day bush?

That particular conundrum is the challenge of this book.

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While writing a book about the past, our own crisis of climate runs through my head. Every day. I find myself grasping for comparisons that aren’t quite clear. I have a friend, old-fashioned in his communication technology, who sends me news clips from newspapers and magazines by mail. He knows I’m working on a book about the Pleistocene and he wants to keep my mind straight. To keep my nose to the grindstone, I post his worst scenario for today’s global warming disaster to the back of a map of Yellowstone Park, where I can’t avoid looking at it.

“By 2100, the Earth’s population will be culled from today’s 6.6 billion to as few as 500 million;” says James Lovelock, independent scientist and father of the Gaia theory, “billions of us will die and the few breeding pairs of people that survive will be in the Arctic where the climate remains tolerable.” Lovelock also thinks: “By 2040, the Sahara will be moving into Europe, and Berlin will be as hot as Baghdad. Atlanta will end up a kudzu jungle. Phoenix will become uninhabitable, as will parts of Beijing (desert), Miami (rising seas) and London (floods). Food shortages will drive millions of people north, raising political tensions. “The Chinese have nowhere to go but up into Siberia.” He hopes that “it doesn’t degenerate into Dark Ages, with warlords running things, which is a real danger.”

Yet Lovelock holds out a glimmer of light: “We are about to take an evolutionary step and my hope is that the species will emerge stronger. It would be hubris to think humans as they now are God’s chosen race.” Lovelock adds: “The human species has been on the planet for a million years now. We’ve gone through seven major climatic changes that are equivalent to this. The ice-ages were shifts in climate comparable with this one that’s coming. And we’ve survived. That series of glaciations and interglacials put the pressures on us to select the kind of human that could adapt. And we’re the progeny of them. And we’re just up against a new and different stress. Maybe we’ll come out better.”

My friend Scotch-taped to the bottom another scrap of newspaper:

“The Republicans are back in control of the House, and they’re bringing something with them: styrofoam cups. The cups, along with plastic forks and a number of other things seen as not eco-friendly, were done away with four years ago by Nancy Pelosi to reduce Congress’s carbon footprint.”

Green activists called the switch an insult to the environment, “Neanderthal” and a slap in the face to efforts to combat global warming.

My friend wonders if Lovelock is suggesting that the Pleistocene glacial fluctuations honed a more adaptable human, better able to cope with, say, the threat of modern global warming? These congressional folk not only don’t believe in global warming, they think it’s an environmental conspiracy. How does evolutionary pressure from the first (the Ice Age) select for the kind of person who seems indifferent to the second (climate change)? According to Lovelock, it should be the other way round. My friend finds grim humor here. Modern humans’ social tendencies paint the battles black and white in a world of friends and enemies; we focus on the fights that matter the least while ignoring what matters most.

A couple more clips, intrusive but closer to the heart of the matter:

The Los Angeles Times reports “Greenland’s Ice Sheet is Slip-Sliding Away.” By 2005, Greenland was losing more ice than anyone expected; the amount of freshwater ice dumped into the Atlantic had almost tripled in a decade. Summer meltwater, responding to recent warmer temperatures, also accelerated. The warm water on the top of the ice sheet made its way through a maze of tunnels, natural pipes and cracks in the ice to the bedrock below, lubricating the slip of ice over Greenland’s rock basement. The meltwater descended thousand of feet in weeks not decades. This was a surprise to scientists. If all glaciers draining the ice sheet slide too quickly, they could collapse suddenly and release the entire ice sheet into the ocean.

“Should all of the ice sheet ever thaw, the meltwater could raise sea level 21 feet and swamp the world’s coastal cities, home to a billion people. It would cause higher tides, generate more powerful storm surges and, by altering ocean current, drastically disrupt the global climate.”

Reuters: Arctic ice sheet may swamp U.S. coasts. The loss of the huge West Arctic Ice Sheet (WAIS) would cause sea levels to rise by 21 feet in North America and 16.5 feet worldwide.

Some scientists warn that the WAIS is fundamentally far less stable than the Greenland because most of it is grounded far below sea level. One expert considers the WAIS collapse is all but inevitable given the current business-as-usual projected warming of 5-7 degrees C.

Arctica’s Ross Ice Sheet is considered even more unstable than the WAIS because it had previously collapsed and could again at any moment. The Ross Ice Sheet collapse would result in an additional 15 feet of sea rise.

Fifty feet of sea rise would demolish the world’s coastal populations, flooding highly populated areas such as Washington, D.C., New York City and the California coastline, and deal disaster to the low-lying Third World, displacing countless millions. And some of these rises could be extremely rapid; the collapse of the Ross Ice Sheet could cause the world’s oceans to rise 15 feet in a week. If all the Arctic and Greenland ice sheets melt, the oceans would rise about 180 feet.

What about the Late Pleistocene? The most dramatic comparison to today’s situation might have been the rising ocean. At the onset of the previous global warming period, known as the Bølling-Allerød, 14,700 years ago and before, when the glaciers were still at their maximum extent, the sea level off British Columbia was 300 to 450 feet lower than today. By 9,000 years ago, the ocean had risen to current levels and, after some local sloshing up and down, settled to where it is now is by 5,500 years ago.

A few scientists are now suggesting that the onset of the warming period following the last glacial maximum might have begun a couple thousand years earlier. The research, some of it from lakes in Alaska, is recent and ongoing. Future research may push that 14,700-date deeper into the Late Pleistocene, say maybe 17,000 years ago, along with earlier dates for the feasibility of navigating the Pacific Coast or the opening of the ice-free corridor. But for the purposes of this book, 14,700 years ago marks the beginning of the warming period.

That amount of ocean rise seems enormous, though moving a shellfish camp might have been easier than relocating skyscrapers. The Pleistocene people would have seen the effects of sea rise as waters slowly drowned the forest of the Pacific continental shelf and glacial flour colored the milky deltas. They would not notice the actual rise of inches per century unless a great chunk of ice, like the Ross, broke off a sheet and fell into the ocean. But they would likely have a collective notion that the climate was changing, much as we have today.

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The end of the Late Pleistocene came suddenly. The global warming that began 14,700 years ago ceased abruptly with a sudden and relatively short-lived cold reversal known as the Younger Dryas (named for an ivory-colored alpine flower with a yellow center that thrived in the cooler air). This was a prolonged cold snap not a re-advance of the glaciers. Isotopes in the Greenland ice indicate the Younger Dryas (YD) began 12,880 years ago and lasted for around 1,300 years, when the warmer modern epoch called the Holocene began.

Causes of the Younger Dryas are hotly debated. One argument posits that the giant freshwater lake perched upon the surface of the North American ice sheet (Lake Agassiz) burst its ice-dam and dumped vast amounts of cold water through the St. Lawrence Valley into the North Atlantic Ocean interrupting the conveyor belt of warm surface water from the south—causing the sudden cooling. Others contend the amount of melt water from Lake Agassiz was insufficient to disrupt the heat conveyor, to the extent that it would alter climate, and that evidence of the eastward flood—flood debris, terraces or an outlet channel—is lacking. Besides, ice cores from the southern hemisphere show that the cooling was worldwide. Likewise, an asteroid theory—an extraterrestrial body smashing into the glacial ice north of the Great Lakes (but leaving no impact crater)—has played to a limited audience, and has been largely, but not entirely, debunked as the precise trigger that brought on the Younger Dryas and drove into extinction the last sabertooths, mammoths, mastodons, dire wolves, horses and short-faced bears (to name a few) in a heartbeat of geologic time.

Whatever the cause, the Younger Dryas cooling was a very big deal in America, and elsewhere; it appeared to precipitate the disappearance of the Clovis culture and their exquisite elephant-hunting spear points, along with the final extinction of the megafauna. The role of climate and human hunting on this great extinction is discussed in Chapter 9.

Worldwide, very close on the heels of the Younger Dryas, the first efforts at agriculture were germinating on an east-west axis emanating from the Fertile Crescent. Somewhere among a dozen or so places in the Middle East or Asia, someone noticed a plant she wanted to eat growing from a place where she had previously spilled wild seeds.

Another revolution was on its way, probably our biggest—the transition from hunting and foraging to farming—one in which we are still floundering, that was born of that last great blast of climate change, its progress unchecked until the burning heat of present day global warming threatens to bake agriculture out of Africa, out of Asia and banish those crops to the gulags of industrial farming in Siberia.

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A ubiquitous stumbling block in telling the story of the Great Adventure is speculating how and if humans could have lived in North America during periods from which there is no archaeological record. Eastern and western Beringia (Alaska and Siberia) before the last glacial maximum (LGM), about 20,000 years ago, is such a place and time. Ecologists attempt to reconstruct Pleistocene environments by analyzing ancient pollen. Beringia about 30,000 years ago was relatively mild, as indicated from lake sediment samples from Siberia, consisting of bogs and larch-birch forests amid a mosaic of tundra. About 3,000 years later, it apparently turned cold and dry.

Some caution is advised here. Scientists sampling selected lakes for spores and pollen amid a mosaic of varied landscapes don’t always get the big picture right. The plant people may conclude the Late Pleistocene habitat was incapable of supporting people or animals, while at the same time paleontologists are finding fossils of big animals all over the place—suggesting the unproductive tundra looked much like an American Serengeti with its vast herds of hoofed critters. Professionals call the contradiction a paradox. The same kind of critical eye should also focus on the interpretation of the Ice Free Corridor as barren and uninhabitable (Chapter 8) or the use of fungal spores to explain Pleistocene extinction (Chapter 9). Some of the claims are specious.

Thus, scientists debate whether the tundra-steppe of eastern Beringia was too cold and dry for people or animals to survive. Palynologists studying ancient pollen cores concluded the Beringian steppe was sparse, tundra-like vegetation, more polar desert than rich grassland. But fossils dredged up by Alaskans sluicing for gold indicate an abundant animal community and contradict this notion: Bison, antelope, musk ox, mammoth, horses, bears and huge cats thrived in this landscape. Finally, botanists suggested, it might have been cold dry tundra but, unlike the mossy tundra of today, rich in grasses, sedges and forbs.

Topographically, if you subtract the glaciers, the Late Pleistocene landforms looked much like they do today. The ice sculpts the mountains into great cirques and knife-edge arêtes and, as it retreats, deposits terminal and lateral moraine that rivers outwash as broad alluvial fans. The rivers melting out of the glaciers were bigger, wider and more braided than today.

Along the southern limits of the ice sheets you might expect to find a thin ribbon of tundra next to the glaciers and along the tops of mountain ranges. Next to the tundra would be a belt of trees—spruce, fir and pine—and then temperate forests of oak, beech and hickory. Up north, the open tundra and steppes would yield to boreal forests or maybe birch and Populus species.

But this is only a most generalized view; in some places oak forests grew almost at the foot of the ice. Winds blew off the glaciers, picking up sand and silt from the outwash, depositing loess throughout the Midwest U.S. and elsewhere. At the edge of the big glaciers, it was windy and cold but no more inhospitable than today’s Arctic.

Like our present day, species of plants and animals tend to migrate up higher on the mountain and northward as the climate warms. That is, if they can: Five-needle stone pines (like whitebark) clinging to the very tops of mountain ranges today have no place higher to go. Neither does the grizzly bear when the corridor to the next productive habitat is a valley blocked by human development and intolerance.

Maintaining corridors, wild areas and wildlife linkages is absolutely critical if we wish to save species of large animals and mitigate a few of the disastrous effects of the Sixth Great Extinction event—the one we are experiencing today.

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The paleozoologist Valerius Geist called our home: “The predator hellhole which was Pleistocene North America.” 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.

•

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 tiger who killed, dismembered and ate Markov waited for him a long time, perhaps days, lurking near the door of his cabin….”

This huge male tiger had previously destroyed everything that had smelled of Markov, and then waited for him to come home. The attack seemed chillingly premeditated.

About this time, as I read on, a chill ran up my own neck. Something about this tiger sounded familiar. How old was this cat? I reread the book but all I could definitively glean was this was a very large male tiger. I think male Siberian tigers, like male grizzlies, continue to grow in size with age. Tigers can live to be 15 years old or so in the wild, although large tigers tend to be targeted by poachers and are therefore rare. The tiger who ate Markov was later killed but never weighed. An experienced eyewitness said he had “never seen a tiger as big as that one.”

A male tiger maintains an exclusive range, driving younger males away or killing them. Siberian tigers have huge territories. Could the killer tiger be ten years old? Possibly. I do the math. Probably, I think. Dmitri Pikunov would know for sure. The book says Dmitri has had a serious heart attack or I would ask him directly: Is the killer tiger the same one we trailed in 1992? We crossed the tracks of the tiger in question four miles southeast of the Markov attack site.

•

Dmitri Pikunov and I were 2-person tent mates on a kayak trip down the wild upper Bikin River in 1992. At least I think it was 1992. I dig out my field notebooks: Yes. Our journey was a buddy trip with five American friends: Jib Ellison, Doug Tompkins, Rick Ridgeway, Tom Brokaw and Yvon Chouinard—famed kayakers and mountain climbers, well, all except myself and perhaps Brokaw. We spent about three weeks in Siberian tiger country, the last ten days fishing and paddling down the wild Bikin River.

We ran into Dmitri in Ternai while struggling to break loose of the Russian bureaucracy and get into the wilderness:

In order to visit the countryside, we are told, it is necessary to secure a permit from the Bureau of Tourism. The Director of Tourism offers us a river trip using our own kayaks for only $2,100, American.

“A truck and motor boat will accompany you at all times,” he says.

This is not exactly what we had in mind. I stare out the window of what until recently used to be the Communist Party building: A pretty girl is walking her cow down the street.

“This is banditry,” says Brokaw who along with Jib has acquired the unsolicited job of group-diplomat. We are getting nowhere. Jib stands up and announces that “We are out of here, we are going home.”

These guys are good sports, they roll with the punches and there is no whining.

By fortune, we run into Pikunov. He knows we are interested in preserving wild country. Dmitri’s greatest personal accomplishment, he tells us, was in helping establish a Native People’s Reserve in the Bikin for the Udege people. The Bikin River country, he argues, is “the most beautiful, most pristine of all.”

“You must see it,” he says. “Hyundai wants to cut it all down and Moscow will cave in to them.”

The die is now cast. We decide to ignore warnings that we must get permission from the KGB to travel: We will try to bribe a helicopter pilot on our own to fly us and our fold-up kayaks into the headwaters of the Bikin River. It can be done, we hear.

We dig into our pockets and come up with a roll of cash that we pass to Dmitri. We find a chopper. Dmitri Pikunov says, “Speak no English.” He covertly passes the roll to the pilot. Soon we are airborne.

We have a single map. The country is huge with no trace of man upon the land. The map shows the middle tributary of the Bikin River, the Zeva River, unfurling counterclockwise, flowing through eroded volcanic hills and cliffs of columnar basalt, finally hooking into the Bikin. That’s where we want to go.

Yvon and I look out the open window of the big military-style Aeroflot helicopter, the port that Rick has opened in order to take some photographs. As our only map of the area is passed back to me, I stupidly grab it in front of the window. In a heartbeat, half the map—the half that shows the Zeva and all the country we plan on kayaking—rips off and is sucked out the window. We are now map-less and I wonder what my carelessness portends.

The boys, especially Tom, will later make me pay heavily for this blunder as the two of us vie for “worst” in kayaking skill.

Nonetheless, rivers tend to run downstream. My journal tells of the last days of our trip, when we walked up the Amba River:

“Amba” means tiger as well as “devil” in the native Udege tongue. We beach at the mouth of the Amba River and walk upstream a short way to a trapper’s cabin (which belonged to the “key witness” in the Markov incident) that Dmitri used in past years during his study of bears and tigers here. The Amba River bottom in summer is hot and humid. Dmitri leads us on a hike several miles up river. Shoulder-high cone fern and alder obstruct our vision. Moss and shelf fungus grow on logs and downfalls. During the winters of his bear study here during the late 1970s, Dmitri would ski along the river and bang on cottonwood trunks with a heavy mace, waking the Asian black bears that hibernated within the hollow trees. The Amba is also prime tiger habitat. China lemon vine grows on the smaller trees, and cow parsnip and nettles make up the under-story. Ticks hang off the low vegetation; we stop for a tick-check every fifteen minutes. This is our last day in the wilds; tonight, we paddle on down to the big Udege village where we can hire a truck to haul us and our fold-up kayaks out to the Trans-Siberian railroad.

We climb a steep hill to a ridge. There is wild boar and black bear sign everywhere. Dmitri signals for us to be quiet. Our crew is noisy, distracted, self-absorbed, talking of industrial collapse and geopolitics. Dmitri snaps at us to shut up. We can hear movement down the ridge. Up ahead we hear the breathing sounds of big animals—probably bears huffing away or boars snorting, all now running downhill.

We blew it. The world is only as big as we allow it to be. Wild places and animals pass along their secrets only if we listen. You have to pay attention. A touch of danger would help. You need to know you can die: A surprise rapids the size of Lava Falls, a bad stretch of black ice across an ice chute, a white-out on a glacier, or maybe a bear or, especially, a tiger. But it’s hard here on our last day out before the slow return home. It’s especially hard in a group; the social dynamics can drain you of vital curiosity and attentiveness.

I split off by myself for a short time. Asian black bear have ripped branches off trees everywhere. I find day beds of boar and bear; there is sign of digging around the large Korean pine trees. The big live oaks are lovely. It’s good to be off alone; I find a bear-ripped honey tree and an ancient yurt on top of the ridge—built by either an Udege trapper or Chinese ginseng hunter.

Dmitri signals for me to rejoin the group. We drop back down to the Amba bottomland, finding an old trail.

Suddenly, Dmitri freezes and motions me forward: A tiger track glistens in the mud. The track in the wallow appears to be only about a

day old, around five inches across—the print, Dmitri says, of a young but dominate (about five years old) male cat that has replaced the previous dominate male cat, who was killed by a poacher. The young tiger leaves scrape marks every few hundred meters and spray scents on territorial tree markers. We stop at such a tree. The bark has been rubbed off by Asian black bears who also are attracted to the strong scent. I get down on my knees and press my nose against the bare trunk.

The pungent fetor of tiger fills my nostrils and—for just a second—I travel with the big cat, orange and black stripes flashing barely perceptibly through the sea of green undulating cone fern, into the wild and predatory world that not so very long ago was my own.

If the huge male tiger who killed, dismembered and ate Markov in 1997 was ten years old, quite likely it was the same then-younger cat whose scent we snorted in 1992 on the Amba River. We were, at that time, less than five miles away from the Markov attack site.

Somehow, this apparent coincidence didn’t hit me as startling: The fact that we probably crossed the sign of a tiger who later tore a man to pieces and ate him, for me, many curious precedents. Deep in the Sierra Madres of Chihuahua, Mexico in 1985, a jaguar coughed and sprayed just beyond the light of my campfire. It was my first jaguar and I glibly imagined this rosette-spotted predator stalking me. The next morning I discovered the jaguar had backtracked me for 14 miles.

And I remember vitality at the edge of fear infused into my own life when my mountain campfire was besieged by a huge black grizzly—he knew me—one stormy autumn night near Glacier Park in Montana: Only a few days earlier the same bear had ripped a cache of camping gear from a tree and had chewed to bits my sleeping bag and sweaty T-shirt, everything that smelled of me, while ignoring a tent and other gear which did not (sending me an unmistakable message: “Get the hell off my mountain.” I did).

The sentience of large predators is unlike what you see gazing into the orbs of a chimp or your favorite Labrador retriever. The tiger with a vendetta or bear with a memory stirs a different set of sensory responses cached deeper down in our brainstems. I knew a grizzly in Yellowstone, one I tracked for a decade, who set up what looked like a deliberate ambush for me in the snowy woods. I had snowshoed into a remote thermal area and later found a huge male grizzly on a winterkilled bull bison. About dusk, the bear rose and followed my snowshoe tracks out onto the crusted snow into the timber. I waited ten minutes and started after him. A few feet into the darkening forest, I stopped and looked at the huge, twisted paw imprinted over my own snowshoe track. A premonition rose up my spine to the hair on my neck. I retreated rapidly and pitched a distant tent in the darkness. The next morning, I cautiously followed the skewed tracks: the big grizzly had trailed my snowshoe prints for a hundred yards, then his tracks veered off sharply in a tight circle that led to an icy depression in the snow behind a large deadfall ten feet off my trail. Had I gone any further in the darkness, he would have been right there. The icy bed spoke of a long wait.

Years later, I investigated a bear mauling: In August of 1984, a woman camper was killed and partially consumed in the backcountry of Yellowstone’s upper Pelican Valley. In late October of that year, I hiked back to the site of the fatality. I squatted to fill my canteen at a small pond. I tensed feeling a sudden tightness in my lungs, then a crushing pain in my chest: In the frozen mud I saw the distinctive track of the big grizzly who would have ambushed me eight years earlier. For a moment, I was disorientated. The tracks were old, unconnected to whatever happened here in August. He probably wasn’t the killer. But he had been right here. I hadn’t known what to make of the snowshoe ambush in 1976 either. Maybe the grizzly was just curious. I felt separated from the magic that once connected me to the grizzly with the crooked track. The authorities never found the bear who killed the young woman. I left the site of the fatal mauling bewildered, isolated from my own kind, wondering how ancient people maintained their humanity among the other nations of animals. An acting park superintendent put out an odd statement: “The last thing we want out there,” he said, “is the legend of a killer grizzly.”

The point of these recollections is that sharing the wilderness with legendary killer bears or cats dramatically shifts the psychic landscape. You think about the world differently because you have no illusions about being in control. If you traveled armed with a spear in Pleistocene North America, you definitely lived in the middle of the food pyramid, stumbling about like a minor but tempting pork chop, hunted by the big cats and bears while you pursued the mammoths and camels of your ice-age vision quests.

•

The most mercurial player remains the gigantic short-faced bear who was a matchless American native. What kind of creature was Arctodus simus: Was it indeed the terror of the tundra, as suggested by a few eminent paleontologists, or a peaceful grazer of the plains?

Considerable academic debate rages about whether the giant short-faced bear was a practicing predator, scavenger or vegetarian. The more interesting question is what sort of challenge Arctodus simus presented to people by appropriating the hunters’ kills and in actually bringing down people as prey. Paleontologists are not a lot of help on this one; they tend not to directly address such human/bear issues.

The core is this: How does it feel to share the land with creatures who are aggressively trying to kill and eat you? It probably felt like it does today, regardless of the rarity of modern human/predator relationships. The hunter who roams the land, spear in hand—looking over his shoulder for the bear or cat that, indifferent to our emerging dominion, regards puny two-legged Homo sapiens as just another variety of pot roast—carries with him a valuable awareness of vulnerability that we lack today in our safe, sterilized woodlots of well-managed white-tail deer and high-powered rifles. That value, I believe, lies in perceiving authentic risk that in turns triggers an appropriate survival response. In such a cosmos, you hear more, see more and smell more. Today’s polluted global winds dilute the olfactory discernment of the shadow of the sabertooth. I’m saying maybe we could use some of this biological insecurity and acuity in today’s world.

It is within that context I consider the short-faced bear.

•

I would think the short-faced bear potential to limit early American demographics too important an issue to be ignored by either archaeologists or paleontologists, although, for the most part, the academics avoid specific speculation. I searched the professional literature for clues and illumination. The venerated vertebrate paleontologist Bjorn Kurten once called Arctodus simus “the most powerful predator in the Pleistocene fauna of North America.” Here is a vulnerable windmill, like “Clovis First,” that makes for great press and it’s something to tilt against. Paleontology often does a good job of debunking popular misconceptions. Archaeology scarcely mentions human/short-faced bear interactions. Paleontology does so only indirectly in a few technical studies—the sort that I endeavor to steer clear of in this book. The reasons are simply to avoid getting snagged in technical detail as well as an acknowledgement of my layman limitations.

Nonetheless, I reluctantly grabbed a handful of recent papers as an example. The representation is probably biased because the ones that caught my attention were either very enlightening or exasperating. They are, however, about the only source for beginning a discussion. The scientist’s conclusions are examined in a stew of my own experiences with grizzly bears. Here’s a summary of three nearly random, technical articles that help paint the panorama. All challenge A. simus’s reputation as a predator.

Spanish paleontologists measured a small number of bone pieces and fragments of short-faced bear fossils and inferred that the bear was not short-faced, long-legged or predacious. One question, which was never asked, is what determines what a bear eats? The answer is behavior, especially aggression, not snout size nor the cut of their omnivore teeth. Animal protein is universally preferred over vegetation. Aggression and dominance played a huge role, especially around the kill sites of Pleistocene carnivores. Predation is opportunistic.

The study purported to compare A. simus to the grizzly bear implying the short-faced bear was a slow moving vegetarian. But grizzlies can outrun racehorses over a short distance and bring down adult elk, caribou, moose and the calves of all these creatures. The short-faced bear evolved in an America without people—grizzlies did not. From my own observations, brown bear routinely displace wolves, cougars and, less commonly, humans from carcasses, presumably because the bear has reason to fear humans. The short-faced bear had no reason to fear H. sapiens because it had never seen one until the late autumn of its species some 13,000 to 30,000 years ago. Since there is no record whatsoever of human interaction with any of these big prehistoric carnivores (there is an anecdotal rumor of a New Mexico Clovis point lodged in a dire wolf’s jaw), my account of such relationships is speculative, based on my own experience with existing American carnivores—polar bears, wolves, cougars, jaguars and brown bears—the most dangerous of which, statistically, is the grizzly (it’s a misleading stat; moose are more of a threat to people).

But all these modern beasts are pussycats compared with those extinct predators.

Other paleontologists studied the teeth, along with some skeletal morphology, of Arctodus simus and concluded the bear’s diet largely consisted of coarse foliage by unselective grazing. I ended up wondering how any bear could survive the Beringian winter by unselected grazing of coarse foliage.