Washington, June 18 : When it comes to sex, female chimps can be really kinky. According to a new study, the females amongst our closest living relatives are more concerned with having sex as many males as possible, and ensuring that they keep quite during the wild act so that other females don't find out.
According to researchers, silence helps them escape punishment from other females for mating with the best males.
The research, by psychologists Simon Townsend and Klaus Zuberbuhler, sheds new light on the sophisticated mental capacities and social intelligence of our closest living relatives.
The St Andrews researchers observed the behaviour of chimps in the Budongo Forest, Uganda, in collaboration with Tobias Deschner of the Max Planck Institute for Evolutionary Anthropology in Leipzig.
They found that chimpanzee females use copulation calls strategically to enlist the future protective support of males against aggressive group members, especially other females.
The females produced more copulation calls when high-ranking males were around but concealed their sexual activity when high-ranking females were nearby.
"Competition between females can be dangerously high in wild chimpanzees. Our findings highlight the fact that these females use their copulation calls in highly tactical ways to minimize the risks associated with such competition," said Simon Townsend.
"The female chimps we observed in the wild seemed to be much more concerned with having sex with many different males, without other females finding out about it, than causing male chimps to fight over them.
"We also found that the calling behaviour of copulating females was unrelated to their fertile period and therefore not linked to the likelihood of conception.
"Copulation calling therefore may be one potential strategy employed by female chimpanzees to advertise receptivity to high-ranked males, confuse paternity and secure future support from these socially important individuals," Townsend added.
The study is published in PLoS ONE on June 18.