Our complex social orders look incomparable to the ones of animals. We created many institutions, codes and norms, in order to perfect the functioning of human population. For example, we invented profession of babysitters in order to get some free time from parenthood. Chimpanzees, on the other hand, employ babysitters for slightly different reasons.
Babysitters are not only human invention at all. However, chimpanzees do not have to go to work and do not want to have a nice dinner at the restaurant. Their reasons are totally different – to wean their infants faster in order to reproduce quicker. Scientists from University of Toronto took a closer look at 42 pairs of chimpanzee mothers and infants at Ngogo, Kibale National Park, Uganda. They wanted to see how babysitters take care of the babies and how babies react to them. And also, of course, what mothers do with the pieces of free time that babysitters provide them with.
It turns out, babies who had babysitters were nursed less often and drank less milk. In other words, regarding food, they were growing more independent than chimpanzees that did not get babysitters. It means that they would go through weaning quicker and mothers could reproduce more frequently. It would look like then that all chimpanzee mothers should be interested in having someone else take care of their offspring, so that they could reproduce more. However, as Iulia Bădescu, lead author of the study, said: “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”.
Scientists also noticed that in some cases mother allowed their babies to nurse for comfort, even when they were not getting any milk anymore. This is done for emotional connection only. Scientists came too all these conclusions by using a novel method of researching faecal samples in order to see what chimpanzee babies eat in the wild. This method is non-invasive and allows scientists seeing when weaning occurs quite accurately.
Social structures are not universal even in chimpanzee communities. However, such knowledge is important for preservation of the species also, because it shows how these animals go about on reproducing more and having a healthier, more independent offspring.