le bonobo plus violent qu'on ne croit

Citation :: As hippies had Altamont, so bonobos have Salonga National Park, where scientists have witnessed the supposedly peace-loving primate hunting and eating monkey children.

The finding could transform both popular and scientific understanding of bonobos, which like chimpanzees share 98 percent of their DNA with humans. But unlike chimps, bonobos have been considered gentle and good-natured: they don't engage in inter-tribal warfare or primate cannibalism, are dominated by females rather than males, and exchange sexual acts with the casualness of humans talking about the weather.

Such easygoing promiscuity has earned bonobos a unique place in the popular imagination — "equal parts dolphin, Dalai Lama, and Warren Beatty," in the words of New Yorker writer Ian Parker. But the reputation is based on limited evidence: most observations come from a couple hundred captive bonobos, and only a few primatologists track our endangered cousin in its remote Congolese home.

One such primatologist is Gottfried Hohmann of the Max Planck Institute for Evolutionary Anthropology, a central figure in Parker's article and author of a study, published yesterday in Current Biology, that describes bands of bonobos tracking, killing and eating young monkeys.

This may be shocking news to bonobo-idealizing humans, but less so to scientists, who have inferred the primate-cannibalizing capacity of bonobos from the presence of monkey fingers in their droppings. For them, the findings provide an opportunity to reconfigure their understanding of a species separated from humans by a mere four million years.

"Now that actual observations have been made, the issue is much clearer, and it changes our perception of bonobo social organization and socio-ecology," said Frans de Waal, a Yerkes National Primate Research Center psychologist who has studied captive bonobos. He called Hohmann's findings a "great discovery," comparing them to field observations of chimpanzees several decades ago, when great variations between chimpanzee populations were first reported.

The findings' most profound implications may involve the nature of sex and violence. "In chimpanzees, male-dominance is associated with physical violence, hunting and meat consumption," said Hohmann in a press release. "By inference, the lack of male dominance and physical violence is often used to explain the relative absence of hunting and meat eating in bonobos."

Even a female-dominated hominid species, it seems, is capable of behavior that would disqualify them from the sort of plaudits served by New York Times science writer Natalie Angier, for whom the bonobo "stands out from the chest-thumping masses as an example of amicability, sensitivity and, well, humaneness."

But much remains to be learned. It is not clear, wrote Hohmann, whether primates are a bonobo dietary staple or last resort, or whether his group is unique in its taste and tactics. In other instances, bonobos have been observed socializing, and even engaging in mutual grooming, with the same monkey species that Hohmann's band killed.

"We cannot exclude the possibility that inter-site variation in hunting behavior, like inter-site variation in tool use and other behaviors of both Pan species, reflects variation in local, socially transmitted traditions," wrote Hohmann.

Like Jack's tribe in Lord of the Flies, Hohmann's bonobos may have gone rogue — a possibility that will no doubt appeal to some bonobo lovers. And to them, de Waal extends more solace: predation, he said, is not the same as aggression, and eating another species is very different from eating your own, as chimpanzees are wont to do.

"This finding does very little to change the idea of bonobos as relatively peaceful primates," said de Waal

http://blog.wired.com/wiredscience/2008/10/free-loving-hip.html