Anna Ilona Roberts

One of the distinctive features of bonobo societies is differences in areas such as communication and social behaviour. However, the evolutionary basis of social and communicative complexity in bonobos is not well understood and studying this complexity can provide insights into how language evolved in our hominin ancestors, as well as the links between sociality and communication in apes. Whilst chimpanzees are well-studied, bonobos are the least studied great ape due to their limited distribution in the Democratic Republic of Congo. This project provides the first insights into social and communicative complexity in bonobos, studying two groups of wild bonobos in the Wamba Committee for Bonobo Research site. This project combined direct observation, analysis of vocal and gestural repertoires to examine the proximate mechanisms of social complexity and establish whether the differences in sociality by the two groups of bonobos are due to environmental factors (differences in the availability of food) or due to communication differences (overlap and repertoire of gestures, use of intentionality markers). A better understanding of group differences in communicative complexity in bonobos is essential both to understand the evolutionary origins of language in humans and to ensure the long-term survival of this endangered species.