Post-conflict behaviour of wild chimpanzees (Pan troglodytes schweinfurthii) in the Budongo forest, Uganda

Since de Waal & van Roosmalen (1979) first documented the occurrence of reconciliation between former opponents in captive chimpanzees, the study of the post-conflict behaviour of primates has provided valuable information about some of the details of primate social organisation. The vast majority of these studies have been carried out on captive subjects and it has been assumed that these findings are representative of wild primates. We set out to investigate whether this was true for the Sonso community of wild chimpanzees ( Pan troglodytes schweinfurthii ) of the Budongo Forest, Uganda, using controlled procedures comparable with those used in captive studies. We found that these chimpanzees were much less likely to reconcile than their captive counterparts. Only one dimension of relationship quality had an effect on the likelihood of reconciliation. Individuals which were highly compatible, in terms of time spent affiliating, reconciled conflicts more often than those with weak relationships. Captive chimpanzees have also been shown to 'console' one another (de Waal & van Roosmalen, 1979; de Waal & Aureli, 1996), where uninvolved bystanders initiate affiliative contacts with victims of aggression. This study did not confirm that consolatory behaviour was characteristic of wild chimpanzee post-conflict behaviour. Nor did these chimpanzees use explicit gestures during post-conflict interactions as they have been shown to do in two out of three captive studies. We conclude that the post-conflict behaviour of chimpanzees is more variable than has previously been thought and is likely to be dependent on the prevailing social environment.