Association and social interactions between strangers and residents in bonobos (Pan paniscus)

This study reports on close spatial association and repeated behavioural in teractions between two strange adult male bonobos with residents of another community. Over a period of 12 months one of the two males developed frien dly social relations to some of the females and other residents, which were indistinguishable From those existing between co-residents. Aggression by resident males against the strangers decreased but the former remained into lerant. The strange males appeared at a time when the number of adult resid ent males was lower as in the years before and when the adult sex ratio (nu mber of adult females per male) was higher as in the years before. Using de finitions from studies on dispersal patterns of male gorillas (HARCOURT, 19 78) and female bonobos (FURUICHI, 1989) the spatial association between the two strange males acid residents could be described as male transfer.