Male Chimpanzees treat Females aggressively to Father More Babies

According to a new study, aggressive male chimpanzees treat females aggressively to force them mate regularly in order to father more babies. The findings of the study have been published in the US journal Current Biology and were based on a long-term study of interactions between chimpanzees in the well-known Gombe National Park in Tanzania.

"These results seem to suggest that males are selected to be aggressive toward females to increase their paternity success, which explains why male-female aggression is observed in so many chimpanzee populations”, said first author Joseph Feldblum of Duke University in a statement.

According to the researchers, male chimpanzees direct surprising amounts of aggression to their female group mates. But previous studies on Chimps’ mating found evidence both for and against the presence of sexual coercion in wild chimps.

To help and resolve the debate, Feldblum and his colleagues observed a chimpanzee community living in the Gombe National Park. This chimpanzee community had been under close examination for the last 50 years.

The researchers knew who had mated with whom and based on genetic tests of paternity they also knew the biological fathers of almost all chimpanzees born in the community since 1995 were.

The researchers studied the effect of male aggression towards females, when the females were sexually receptive and when they were not.

The researchers found that male aggression at the time of a female's sexually receptive periods led to more regular mating but not bigger paternity success.

High-ranking males that were aggressive toward females when those females were not sexually receptive were rewarded for their bullying with more offspring.

From the findings, it was found that long-term patterns of intimidation let high-ranking males to boost their reproductive success, offering possibly the first genetic evidence of sexual coercion as an adaptive strategy in any social mammal.