Study shows chimps exchange meat for sex

LEIPZIG, Germany, April 8 (UPI) -- Wild female chimpanzees have been found to be more likely to have sex with males that give them meat on a regular basis, German researchers say.

The researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, said that although male chimps have been shown to share meat extensively with females, there had not been much direct evidence to support the meat-for-sex hypothesis before this study.

But the German researchers said 22 months they learned female chimps copulated more frequently with males who shared meat with them. They said they ruled out alternative theories by controlling the rank of the male, as well as the age, rank and gregariousness of the female. Also taken into account was whether the females were in estrous, or at the height of their reproductive cycle.

"These results strongly suggest that wild chimpanzees exchange meat for sex, and do so on a long-term basis," they wrote in an article that appeared in the journal PLoSONE. "Similar studies on humans will determine if the direct nutritional benefits that women receive from hunters in foraging societies could also be driving the relationship between reproductive success and good hunting skills."