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