If you live in a developed country, odds are you are going to die of a heart attack, stroke, cancer or an accident. But it was not always this way. For most of our evolutionary history as primates, one of the most common causes of death, perhaps the most common cause, was, well, being eaten.
From This Story
Starting with the first primates, which evolved about 65 million years ago, our ancestors were about the size of a monkey, if not smaller. Larger apes evolved about 13 million years ago, eventually producing today’s gorillas, chimpanzees, orangutans, bonobos and us. Hominids, including our direct ancestors, split from chimps and bonobos about seven million years ago, and our own species, Homo sapiens, is only about 200,000 years old. Evidence of our historic fates comes from knowing what eats monkeys or apes today, and from studying what ate now-extinct species. For example, many of the best fossils of hominids come from piles of bones near places where predators ate lunch.
Here then are ten of the animals likely to have killed our ancient and not so ancient kin. The fact that you are alive means your direct ancestors escaped these fates, if not forever then at least long enough to reproduce.
1. Lions and tigers and leopards, oh #$*@!
Leopards are extraordinarily good at eating primates. They are stealthy. They run fast (at least faster than our ancestors). They leap powerfully (up into primates’ sleeping trees). And they can carry great weights (our bodies) to wherever it might be safe for them to pause and dine. With this combination of traits, leopards have been breathing down our necks for as long as 10 million years.
Today’s leopards show what our ancestors had to contend with. In one study in South Africa’s Kruger National Park, 70 percent of baboon deaths were attributed to African leopards. In another study, half of the mammals that leopards killed were monkeys or chimpanzees; they also kill young gorillas. When scientists pick through leopard scat, many of the bones they find are from primates—ribs, fingers, toes and skulls, all of them remarkably similar to our own skeleton. Baboons seem to get eaten by leopards at night, monkeys during the day. Scientists, on the other hand, are most likely to get eaten when they pause while picking through leopard scat to say, “Hey, I think this looks fresh!”
Primates, including humans, are also eaten by lions in Africa, tigers in the Asian tropics, and cougars and jaguars in the Americas. A single troop of chimpanzees in Tanzania had four of its members eaten by lions in just a few days in 1989. The authors of that study reported, a bit somberly, that the “responses of chimpanzees to lions included alarm calls, whimpers, climbing into trees, and silence.” We have no reason to believe our ancestors’ responses were any different.
2. The first humans to fly
I tease my neighbor because she worries about red-tailed hawks carrying off her small dog, but the truth is that not so long ago, eagles would have carried off our small children. One of the most famous hominid fossils is the skull of a 3-year-old child found in Taung, South Africa. The Taung child was a member of the Australopithecus africanus species, which lived in Africa from about three million to two million years ago. The skull has holes neatly punched into its eye sockets; they were made by the talons of a large bird akin to an African crowned eagle. The skull was found among other bones under what has been interpreted as a nest. More recently, great piles of roughly five-million-year-old fossil monkey skulls, many of them with talon holes, were discovered in Angola under what appear to have been four separate eagle nests.
Today, 90 percent or more of the prey of crowned eagles in Kibale National Park in Uganda are primates, mostly cercopithecoid monkeys. Primates are also the favorite prey of harpy eagles in the tropical forests of the Americas. Perhaps the clearest indication of just how important predation, and predation by birds in particular, is in primate evolution comes from the lexicon of monkeys. Monkeys have distinct calls for different predators. Those terms include, “cat,” “snake” and, to paraphrase, “oh crap, eagle.” “Ohcrapeagle” may well have been one of the first human words.