Babysitter helps female chimps to wean offspring faster

Looks like even chimps get benefitted by the babysitters.

A University of Toronto study says that it may even mean that mothers can wean their infants faster, which can allow them to reproduce again more quickly, with the help of babysitters.

The 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 the study, two particular aspects of care that these other individuals provided, was taken into consideration: 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.

However, in a separate study, the researcher and her colleagues found that chimpanzee mothers let their "toddlers" nurse for comfort, even after lactation was over and they were receiving no milk.

"Infants who were held and carried more by babysitters, nursed less often and drank less milk," said lead author of the study Iulia Badescu. "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."

"But not all chimpanzee mothers relied on babysitters, and in fact, in other chimpanzee communities, babysitting may be a behaviour that rarely occurs. Our findings emphasize the significance of babysitting as a flexible component of female reproductive strategies in some species," Badescu added.

The researchers employed a novel method in both studies to arrive at their conclusions, analyzing fecal samples to determine what the contribution of maternal milk was to the diet of the chimpanzee infants.

The study has been published in Royal Society Open Science Journal.