Offspring of dominant chimp mothers win more fights

Like human beings, a dominant mom helps young chimpanzees win playground fights, shows a new study.

An analysis of 12 years of observations of playground fights between young chimpanzees in East Africa finds that chimps with higher-ranked moms are more likely to win.

The results come from an analysis of daily field notes recorded from 2000 to 2011 at Gombe National Park in western Tanzania.

"We wanted to find out what role moms play in helping young chimpanzees establish dominance within their groups," said Catherine Markham, assistant professor at Stony Brook University and lead author of the study.

The records are part of a larger database containing more than 50 years of data on over 300 wild chimpanzees.

During the time of their study, chimps under 12 engaged in nearly 140 fights, mostly between non-siblings.

The researchers determined the winner of each fight based on which chimp did most of the hitting, kicking, biting or chasing, and which one squealed, cried or ran away.

When they analysed the effect of parental pecking order, the chimps with higher-ranking mothers were more likely to win.

"In other primate species you see moms swooping in to intervene and help their offspring," said Carson Murray, assistant professor at George Washington University and co-author.

The researchers' next step will be to compare the outcome of fights when mom is nearby to fights when mom is further away.

"It could be that chimps are more bold or confident or their opponents are more scared when the moms are close," Murray said.

The results could help explain why the offspring of higher-ranking chimpanzee females are more likely to survive, concluded the authors.

The study appeared online in the journal Animal Behaviour.