How Monkeying Around Can Get You in Trouble with Chimps

Chimpanzees are apes, not monkeys. 

Chimpanzees hunt monkeys for meat.

Chimpanzees not only hunt monkeys, but they hunt in groups, and share the meat afterwards.

Some Chimpanzees, called 'impact hunters,' are more gung ho about hunting moneys than other chimpanzees are.

Individual differences in risk-taking and hunting aggression may originate from individual genetic differences.

These are some of the 'fun facts' shared by Ian Gilby, Senior Research Scientist in the Department of Evolutionary Anthropology and co-director of the Jane Goodall Institute Research Institute at Duke University. Gilby spoke at a Thursday night Science Cafe at the North Carolina Museum of Natural Sciences (where I am lucky enough to be a summer sci-comm intern!) The Science Cafes at the museum are a part of a new late-night program at the museum on Thursday nights, when museum visitor can enjoy exhibits without the weekend crowds.

“I’ve always been interested in how animals interact with one another,” Gilby said during his Science Café talk. “Cooperation is particularly interesting, because it is a puzzling thing. A lot of people might be surprised to know that chimpanzees actually hunt monkeys, eat them, and unfortunately tear the carcasses apart and share the meat with other members of their community.”

But why would chimpanzees help each other? Why would they share meat from a monkey kill? Why do they hunt in groups, and why would multiple chimps participate in a risky group hunt if they could simply bum meat off of other individual chimpanzee hunters?

“A group hunt is a risky, energetically expensive thing, to climb into the trees and catch a money that is trying to get away, is big, has canines and will bite you,” Gilby said. “If you could somehow get meat from one of your pals, without actually taking a risk yourself, why would you do it?”

In order to investigate this question, Gilby and colleagues have been in the process of collecting years’ worth of observational data in the field, following chimpanzees around in the wild to observe their behaviors. Gilby has collected more than 4 years of observational data on chimpanzee hunting behavior in the field.

A key finding from his long-term data collection, Gilby says, has been the finding that while hunting among chimpanzees is a group effort, key males, known as “impact hunters,” are highly influential within the group.

“We are finding with the chimps that there is a real variation in how cooperative individuals are, and how prone to risk-taking they are,” Gilby said. “What I think is one of my most exciting discoveries is what I call impact hunters; these are certain males who are just really gung ho hunters. For some reason, they have a different threshold, and they go after the monkeys before anyone else does. But when they do that, what they are doing is actually changing the equation for all the other chimps.”

Still interested? Read more of this post on the NC Museum of Natural Sciences blog!