Original URL: http://www.theregister.co.uk/2009/04/08/chimp_deals/
Male chimps strike 'meat for sex' deals
Sharing food brings reproductory success
Researchers have confirmed that male chimpanzees who share meat with females mate twice as often as those who prefer to keep their food to themselves.
These "meat for sex" deals, observed among chimps in Ivory Coast by Dr Cristina Gomes and colleagues from the Max Planck Institute for Evolutionary Anthropology, are significant because they're "long-term" arrangements: Males will share meat from hunting expeditions with females even when they're not in oestrus, thereby increasing the possibility of copulation when they are.
Previous attempts to confirm the "meat for sex hypothesis", that male chimps might woo females with food, failed since they focused on "direct exchanges", in which sharing resulted in immediate copulation.
Dr Gomes explained to the BBC: "We looked at chimps when they were not in oestrus - this means they don't have sexual swellings and aren't copulating. The males still share with them - they might share meat with a female one day, and only copulate with her a day or two later."
She added: "By sharing, the males increase the number of times they mate, and the females increase their intake of calories. 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."
Dr Gomes suggested the findings might offer insights into human evolution. The team's report specifies: "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."
The full report is published here in PLoS ONE. ®