Female chimpanzees employ babysitters to wean young faster

Date: November 9, 2016
Source: University of Toronto

A babysitter can make a big difference in a parent's life. For wild chimps in Uganda, it may even mean that mothers can wean their infants faster, which can allow them to reproduce again more quickly.

A University of Toronto study looked at 42 pairs of chimpanzee mothers and infants at Ngogo, Kibale National Park, Uganda. They wanted to better understand the impact of "alloparenting" -- or babysitting -- when individuals other than the mother assisted with infant care.

In a paper published in the Royal Society Open Science (RSOS), they describe looking at two particular aspects of care that these other individuals provided: infant handling, that is carrying and holding the infants, and natal attraction, the interest in infants demonstrated through behaviours like grooming and playing.

The researchers compared whether the extent of involvement of these individuals impacted the proportion of time that mothers spent foraging, the rates that infants nursed, and the contribution of milk to infants' diets.

"Infants who were held and carried more by babysitters, nursed less often and drank less milk," said Iulia Badescu, a PhD candidate in Evolutionary Anthropology at the University of Toronto, and lead author of the study. "This means that they were becoming more nutritionally independent compared to infants of the same age who were babysat less or not at all. They were going through the weaning process quicker, and would likely be done weaning at a younger age."



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