Die soziale Kommunikation von Bonobos (Pan pansicus)
Final Report Abstract
The project "The Social Communication of Bonobos (Pan paniscus)" aimed to investigate the communicative signalling of bonobos focusing on vocalizations and gestures. The project centered on a comparison of the main vocalizations used by captive and wild bonobos, to determine if group- and/or context-specific calls exist. Positive results in the first case would have allowed me to address the role of vocal learning. In the second case, it would have been indicative of referential signaling, leading to future studies using controlled playbackexperiments. However, since a second field trip to the Democratic Republic of the Congo had to be cancelled due to political instability in 2007, a comparison between vocalizations of wild and captive animals could not be achieved. The focus of the analysis was therefore shifted toward an understanding of the use of sex calls and the use of gestures during social games and is based on data of bonobos in captivity only. The following two questions were addressed: 1) Does the use of communicative gestures to encourage reluctant partners in social games suggest rudimentary understanding of others' intentions? 2) What is the use and function of vocalizations during genital contacts in bonobo females? Concerning the use of gestures during social games, the results showed that bonobos behaved in many ways similar to human children in this particular context. They were interested in the joint activity, rather than the play objects themselves, and used communicative gestures to encourage reluctant partners to perform their role, suggesting rudimentary understanding of others' intentions. Focusing on the sexual behaviour of bonobo females during food encounters, the present results provide further evidence that the sexual behaviour of bonobos is greatly detached from reproduction. In addition, these data represent the first evidence that bonobos combine sexual behaviour and vocalizations to convey information not only to the sexual partner but also to bystanders. It therefore might be possible that bonobos use communicative strategies to announce a sexual trade.
