Jealous female gorillas ply their silverback with sex to fight off the competition, a study suggests.
Researchers at Zoo Atlanta in Georgia found that the female apes were more amorous on days their peers were having sex – even when they could not fall pregnant themselves.
Dr Tara Stoinski and her team monitored four female apes for two years, counting how often they approached their mate and actually had sex.
According to New Scientist magazine, even females who were already pregnant or breastfeeding young copulated more often when their peers were on heat.
It has previously been suggested that females solicit ‘non-reproductive sex’ – when they copulate despite being unable to conceive – to make males believe they could be the father.
But the females at Atlanta Zoo had only one silverback to father their young, discounting this theory.
Dr Stoinski believes the females upped their stakes with the male to stop him from inseminating the other three.
She said: ‘With another female in the mix, the male may copulate less with the first one, or he could be depleting his sperm.’
In their natural habitats, females could compete for the male’s attention so that he protects their young.
Full story here.