Sekine / Poster

Development of social play in captive chimpanzees: preliminary observation in Tama Zoological Park, Tokyo

Sumirena Sekine and Hideko Takeshita, Division of Lifestyle Studies, Graduate School of Human Cultures, University of Shiga Prefecture

     In order to be maintained, social play necessitates consent from the partner, or the adjustment of one's behavior according to physical conditions or the cognitive development of the partner. Objects in the environment can also play important roles in initiating and maintaining social play contexts in humans. Development of social play in chimpanzees, the closest relatives of humans, may be related to the development of cognitive abilities, not only in social but also in technical aspects. This research aims to clarify characteristics of social play in captive chimpanzees (Tama Zoological Park, Tokyo) and to examine the development of chimpanzee social play in relation to cognitive development, through longitudinal observation. The present report is based on preliminary observation, conducted for a total of 27 hours focusing on 5 individuals (3 males and 2 females, 9 months to 5 year of age). Our results were threefold. 1) Several basic elements of play were distinguished, including chasing, wrestling, gnawing, and hitting. 2) It was suggested that not only preference towards the partner but also physical and cognitive development influenced the duration of bouts and the complexity of patterns in social play. 3) Behavioral variation in invitation to social play was observed among the subjects.