Dr. Michael Wilson, the curly-haired young director of field research at Gombe Stream, vouches for their strength. He has watched them tear apart and devour red colobus monkeys. Superb hunters, about 80 percent of their attempts are successful kills. “For lions, it’s only about one out of 10 or 20. These are pretty bright creatures.”
But he has also seen them steal into the territories of neighboring chimp groups, ambush unwary lone males, and maul them to death. He’s watched chimps over months patiently pick off males of neighboring clans until the territory and the females are theirs. He’s also seen pitched chimpanzee combat, and blood battles within a group to determine who is the alpha male. The unavoidable comparisons to human aggression and power struggles became his research specialty.
“I get tired of thinking about it. It’s kind of depressing.”
One of the unfathomables is why bonobos, smaller and more slender than chimps but equally related to us, don’t seem very aggressive at all. Although they defend territory, no intergroup killing has ever been observed. Their peaceful nature, predilection for playful sex with multiple partners, and apparent matriarchal social organization with all the attendant nurturing have practically become mythologized among those who insistently hope that the meek might yet inherit the Earth.
In a world without humans, however, if they had to fight it out with chimpanzees, they would be outnumbered: only 10,000 or fewer bonobos remain, compared to 150,000 chimpanzees. Since their combined population a century ago was approximately 20 times greater, with each passing year chances weaken for either species to be around to take over.
Michael Wilson, hiking in the rain forest, hears drumbeats that he knows are chimpanzees pounding on buttress roots, signaling each other. He runs after them, up and down Gombe’s 13 stream valleys, hurdling morning glory vines and lianas strung across baboon trails, following chimp hoots until, two hours later, he finally catches them at the top of the Rift. Five of them are in a tree at the edge of the woodland, eating the mangoes they love, a fruit that came along with wheat from Arabia.
A mile below, Lake Tanganyika flashes in the afternoon sunlight, so vast it holds 20 percent of the world’s freshwater and so many endemic fish species that it’s known among aquatic biologists as the Galapagos of lakes. Beyond it, to the west, are the hazy hills of the Congo, where chimpanzees are still taken for bush meat. In the opposite direction, past Gombe’s boundaries, are farmers who also have rifles, and who are tired of chimps who snatch their oil palm nuts.
Other than humans and each other, the chimpanzees have no real predators here. The very presence of these five in a tree surrounded by grass testifies to the fact that they’ve also inherited the gene of adaptability, and are far more able than gorillas, which have highly specialized forest diets, to live on a variety of foods and in a variety of environments. If humans were gone, however, they might not need to. Because, says Wilson, the forest would come back. Fast.
“There’d be miombo moving through the area, recovering the cassava fields. Probably the baboons would take first advantage, radiating out, carrying seeds in their poop, which they’d plant. Soon you’d have trees sprouting wherever there’s suitable habitat. Eventually, the chimps would follow.”
With plenty of game returning, lions would find their way back, then the big animals: cape buffalo and elephant, coming from Tanzania’s and Uganda’s reserves. “Eventually,” Wilson says, sighing, “I can see a continuous stretch of chimpanzee populations, all the way down to Malawi, all the way up to Burundi, and over into Congo.”
All that forest back again, ripe with chimpanzees’ favorite fruits and a prospering population of red colobus to catch. In tiny Gombe—a protected shred of Africa’s past that is also a taste of such a posthuman future—no enticement is readily evident for another primate to leave all that lushness and follow in our futile footsteps.
Until, of course, the ice returns.
CHAPTER 5
The Lost Menagerie
IN A DREAM, you walk outside to find your familiar landscape swarming with fantastic beings. Depending on where you live, there might be deer with antlers thick as tree boughs, or something resembling a live armored tank. There’s a herd of what look like camels—except they have trunks. Furry rhinoceroses, big hairy elephants, and even bigger sloths—sloths?? Wild horses of all sizes and stripe. Panthers with seven-inch fangs and alarmingly tall cheetahs. Wolves, bears, and lions so huge, this must be a nightmare.
A dream, or a congenital memory? This was precisely the world that
AMONG THE VARIOUS slurs hurled at sitting presidents throughout the history of the United States, the epithet with which Thomas Jefferson’s foes smeared him in 1808 was unique: “Mr. Mammoth.” An embargo that Jefferson slapped on all foreign trade, intended to punish Britain and France for monopolizing shipping lanes, had backfired. While the U.S. economy was collapsing, his opponents sneered, President Jefferson could be found in the East Room of the White House, playing with his fossil collection.
This was true. Jefferson, a passionate naturalist, had been enthralled for years by reports of huge bones strewn around a salt lick in the Kentucky wilderness. Descriptions suggested that they were similar to remains discovered in Siberia of a species of giant elephant, thought by European scientists to be extinct. African slaves had recognized big molars found in the Carolinas as belonging to some kind of elephant, and Jefferson was sure these were the same. In 1796 he received a shipment, supposedly of mammoth bones, from Greenbriar County, Virginia, but a huge claw immediately alerted him that this was something else, possibly some immense breed of lion. Consulting anatomists, he eventually identified it and is credited for the first description of a North America ground sloth, today named
Most exciting to him, though, were testimonies by Indians near the Kentucky salt lick, allegedly corroborated by other tribes farther west, that the tusked behemoth in question still lived in the north. After he became president, he sent Meriwether Lewis to study the Kentucky site on the way to joining William Clark for their historic mission. Jefferson had charged Lewis and Clark not only with traversing the Louisiana Purchase and seeking a northwest river route to the Pacific, but also with finding live mammoths, mastodons, or anything similarly large and unusual.
That part of their otherwise stunning expedition proved a failure; the most impressive big mammal they cited was the bighorn sheep. Jefferson later contented himself with sending Clark back to Kentucky for the mammoth bones that he displayed in the White House, today part of museum collections in the United States and France. He is often credited with founding the science of paleontology, though it was not really his intention. He’d hoped to belie an opinion, espoused by a prominent French scientist, that everything in the New World was inferior to the Old, including its wildlife.
He was also fundamentally mistaken about the meaning of fossil bones: he was convinced that they must belong to a living species, because he didn’t believe that anything ever went extinct. Although often considered America’s quintessential Age of Enlightenment intellectual, Jefferson’s beliefs corresponded to those held by many Deists and Christians of his day: that in a perfect Creation, nothing created was ever intended to disappear.
He articulated this credo, however, as a naturalist: “Such is the economy of nature that no instance can be produced of her having permitted any one race of her animals to become extinct.” It was a wish that imbued many of his writings: he wanted these animals to be alive, wanted to know them. His quest for knowledge led him to found the University of Virginia. Over the next two centuries, paleontologists there and elsewhere would show that many species had in fact died. Charles Darwin would describe how these extinctions were part of nature itself—one variety morphing into the next to meet changing conditions, another losing its niche to a more powerful competitor.
Yet one detail that nagged at Thomas Jefferson and others after him was that the big-mammal remains
