Is birth attendance a uniquely human feature? New evidence suggests that bonobo females protect and support the parturient

Birth attendance has been proposed as a distinguishing feature of humans ( Homo sapiens ) and it has been linked to the difficulty of the delivery process in our species. Here, we provide the first quantitative study based on video-recordings of the social dynamics around three births in captive bonobos ( Pan paniscus ), human closest living relative along with the chimpanzee. We show that the general features defining traditional birth attendance in humans can also be identified in bonobos. As in humans, birth in bonobos was a social event, where female attendants provided protection and support to the parturient until the infant was born. Moreover, bystander females helped the parturient during the expulsive phase by performing manual gestures aimed at holding the infant. Our results on bonobos question the traditional view that the " obligatory " need for assistance was the main driving force leading to sociality around birth in our species. Indeed, birth in bonobos is not hindered by physical constraints and the mother is self-sufficient in accomplishing the delivery. Although further studies are needed both in captivity and in the wild, we suggest that the similarities observed between birth attendance in bonobos and humans might be related to the high level of female gregariousness in these species. In our view, the capacity of unrelated females to form strong social bonds and cooperate could have represented the evolutionary pre-requisite for the emergence of human midwifery.