April 9, 2009

Wild chimps exchange meat for sex

German scientists say they've determined wild female chimpanzees copulate more frequently with males who share meat with them over long periods of time.

Max Planck Institute for Evolutionary Anthropology researchers Cristina Gomes and Christophe Boesch said their findings strongly suggest that wild chimpanzees exchange meat for sex and do it on a long-term basis.

Males who shared meat with females doubled their mating success, whereas females who had difficulty obtaining meat on their own increased their caloric intake without suffering the energetic costs and potential risk of injury related to hunting, said Gomes. Previous studies might not have found a relationship between mating success and meat sharing because they focused on short-term exchanges; or perhaps because in those groups access to females was driven by male coercion so females rarely chose their mating partners.

Boesch said the findings add to the ever-growing evidence suggesting that chimpanzees can think in the past and the future and that this influences their present behavior.

The study is detailed in the online journal PLoS One.