The best way to a chimp's heart is through her stomach

Chimpanzees enter into "deals" whereby they exchange meat for sex, according to researchers.

Male chimps that are willing to share the proceeds of their hunting expeditions mate twice as often as their more selfish counterparts.

This is a long-term exchange, so males continue to share their catch with females when they are not fertile, copulating with them when they are.



Cristina Gomes and her colleagues, from the Max Planck Institute for Evolutionary Anthropology in Germany, studied chimps in the Tai Forest reserve in Ivory Coast. She and her team observed the animals as they hunted, and monitored the number of times they copulated.

"By sharing, the males increase the number of times they mate, and the females increase their intake of calories," said Dr Gomes.

"What's amazing is that if a male shares with a particular female, he doubles the number of times he copulates with her, which is likely to increase the probability of fertilising that female."