AbstractKnowledge of periparturitional behaviors in captive primates may contribute to infant survival and is particularly important for endangered species, such as the bonobo, or pygmy chimpanzee (Pan paniscus). Given that the bonobo is considered to be closely related to humans, such knowledge also may offer insights about the evolutionary development of complex maternal patterns. To date, however, only one observation of aP. paniscusbirth has been reported. The periparturitional behaviors of a mature bonobo (P. paniscus) female during the pregnancy and birth of two infants are described in detail. Information not previously reported for the species is included. Periparturitional behaviors were similar for both births.