Chimps: More males means boundary fights

October 18, 2005

University of Michigan scientists say the biggest predictor of territorial boundary patrols among wild chimpanzees is the number of males in the group.

Chimpanzees will sometimes attack and kill their neighbors during rarely observed boundary patrols, said John Mitani, professor of anthropology and co-author of the study with David Watts of Yale University.

Scientists have known for about 25 years that boundary patrol fatal attacks occur, the question has been what accounts for the varying number and frequency of such patrols and attacks.

During boundary patrols, a group of males will rise without warning, form a single file line and silently depart the group, Mitani said.

"What they are doing is actually seeking signs, if not contact, with members of other groups," Mitani said. "If the patrollers outnumber them, then they will launch an attack." During the attacks, the chimps beat and often kill their neighbors, but the patrols are apparently an important part of chimp society.

"They take up about two hours out of a 12-hour work day," Mitani said. "That is not trivial exercise..."

Added Mitani: "I think it's difficult to make any general conclusions about what this says about human behavior."

Copyright 2005 by United Press International

Explore further: Why chimpanzees attack and kill each other

Related Stories

Why chimpanzees attack and kill each other

June 21, 2010

Bands of chimpanzees violently kill individuals from neighboring groups in order to expand their own territory, according to a 10-year study of a chimp community in Uganda that provides the first definitive evidence for this ...

Recommended for you

Which came first—the sponge or the comb jelly?

December 1, 2015

Bristol study reaffirms classical view of early animal evolution. Whether sponges or comb jellies (also known as sea gooseberries) represent the oldest extant animal phylum is of crucial importance to our understanding of ...

Making 3-D imaging 1,000 times better

December 1, 2015

MIT researchers have shown that by exploiting the polarization of light—the physical phenomenon behind polarized sunglasses and most 3-D movie systems—they can increase the resolution of conventional 3-D imaging devices ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.