Richard Collins: Learn about the 'common enemy effect' from bonobos

Creatures facing a new threat, real or perceived, tend to draw closer to their peers. Forming alliances, they become more willing to cooperate with each other

Bonobo (left) and Chimpanzee (right) Although they may look very similar, bonobos and chimpanzees were identified as two distinct species of great ape in 1929. Bonobos have a more slender, gracile build than chimpanzees, who are considered more robust. From birth, bonobos tend to have dark faces with pink lips and hair that often looks as if it were parted down the middle. Chimpanzees, on the other hand, are usually born with light faces that freckle and darken with age. Image: Ape Initiative 

Unusual chimpanzee specimens were sent from Bolobo, on the Congo River, in the 1920s. Somebody, misspelling the town’s name, wrote ‘Bonobo’ on a shipping crate destined for Europe. German zoologist Eduard Tratz and the Austrian Heinz Heck, of ‘Heck’s cattle’ fame, began calling the strange chimps ‘bonobos’. Like Captain Boycott, the sender had unwittingly added a new noun to the lexicon.

Scientists once thought that chimpanzees, our closest animal relatives, were peace-loving vegetarians. Other great apes, the gorillas, orangutans, and humans, were known to kill during conflicts. Lesser apes, the gibbons, were also occasional killers. Chimps, however, seemed never to resort to violence, until it was discovered that these ‘white-haired boys’ of the ape tribe ambushed monkeys and ate their flesh.