Despite their reputation as lovers not fighters of the primate world, bonobos actually hunt and eat other great apes, German researchers said Monday.
Their findings, the first direct evidence of hunting by the so-called "hippie" apes, show that such behaviour is not linked to male dominance as females rule bonobo society and also go on hunts.
"We always have this view that hunting is a male business," said Gottfried Hohmann of the Max-Planck Institute for Evolutionary Anthropology in Leipzig, Germany. "What our study shows is this is not necessarily the case.
"This has implications for models on early humans that people have proposed how humans have evolved," said Dr. Hohmann, whose findings are published in Current Biology.
Bonobos, chimpanzees, gorillas and orangutans, collectively known as the great apes, are the closest genetic relatives to humans and scientists study their behaviour to learn more about our own evolution. Bonobos have generally been considered more peaceful than their close cousins, the chimps, and have a reputation for free-loving ways because sex plays a major role their society, being used for greetings, conflict resolution and reconciliation.
Scientists had thought bonobos, found in the lowland forest south of the river Congo, only ate small animals such as squirrels, forest antelopes and rodents they encountered.
Over five years of observing one group, however, the researchers recorded about 10 instances when it set out to hunt chimpanzees.
Each time, the bonobos silently crept through the woods on the ground, trying to get underneath a group of chimps before clambering up a tree in a sudden attack, the researchers said.
The bonobo hunts were successful on fewer than half the excursions and in some cases shared the meat, evidence that they were willing to share to encourage group hunting, Dr. Hohmann and his colleagues said.
