Bonobos and the evolution of male aggression

Bonobos are considered the progressive poster children of the primate world, living lives of relative harmony and copious sex.

Females have a higher social status than males, and the latter are known for the distinct lack of physical violence that characterises their counterparts in chimpanzee society.

The hunting of other primate species by packs of male chimps has much to do with their reputation for aggression and male dominance, a reputation bonobos have avoided so far.

Bonobos are known to supplement their diet with antelopes, squirrels and rodents, but have not been observed hunting other primates, until now.

In a study published in Current Biology, researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig report three instances of bonobos hunting and eating primate prey, and two unsuccessful hunts.

Female bonobos were involved in the pursuit, behaviour not observed in chimps.

The researchers – Martin Surbeck and Gottfried Hohmann – have been observing bonobos in their natural habitat in the Salonga National Park in the Democratic Republic of Congo for five years.

They suspected bonobos did in fact hunt other primates as evidence had been found in faecal matter, including a digit from a monkey.

The researchers say the observations are important for discussions about male dominance and bonding, aggression and hunting, Hohmann said in a statement.

“In chimpanzees, male-dominance is associated with physical violence, hunting and meat consumption,” he said. “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.

“Our observations suggest that, in contrast to previous assumptions, these behaviours may persist in societies with different social relations.”

“Primate hunting by bonobos at LuiKotale, Salonga National Park” by Surbeck and Hohmann [doi:10.1016/j.cub.2008.08.040] is published in Current Biology.