EVIDENCE FOR AN IMPORTANT SOCIAL-ROLE OF ALLOGROOMING IN A PLATYRRHINE PRIMATE

Allogrooming behaviour was analysed in a wild group of tufted capuchin monkeys, Cebus apella, in Iguazu National Park, Argentina. Evidence i s provided that allogrooming in this platyrrhine species serves an imp ortant social function, as has been demonstrated for catarrhine primat es. Using ad libitum sampling, 654 grooming sessions were recorded dur ing 740 contact hours with one group. Seasonal variation was found in daily time allocation to allogrooming and the mean duration and recipr ocity of sessions. Individual dominance rank was an important determin ant of grooming relationships. The dominant male and female were the m ost actively involved in grooming. Among adults, dominant individuals were involved in more sessions than were subordinate individuals. The females maintained strong grooming relationships with each other and t ended to reciprocate more within sessions than did males. Oestrous fem ales engaged in more grooming bouts with adult males than did non-oest rous females. Females with newborn infants were attractive social part ners for the remaining members of the group. A social function for all ogrooming in Cebus is indicated by the close relationship between allo grooming, the social system and coalition formation, and by the change s in quantity and direction of grooming in response to oestrous behavi our and to the birth of infants. (C) 1997 The Association for the Stud y of Animal Behaviour.