Dyadic and triadic aggression and assertiveness in adult female rhesus monkeys, Macaca mulatta, and hamadryas baboons, Papio hamadryas

Abstract

Abstract. Aggressive interactions were observed in two primate species: rhesus monkeys, which have a female-bonded social system, and hamadryas baboons, which have a non-female-bonded social system. Dyadic and triadic aggression and assertiveness were examined under controlled ecological conditions and demographic structure, focusing on interactions initiated by adult females between and within two groups of each species. The literature suggests that rhesus monkeys interact with a broad class of partners while hamadryas baboons have limited social interactions. Primates have flexible social systems, however, and differences are probably not due to species specificity. Rhesus females used dyadic interactions more frequently in conflict situations while hamadryas females often involved a third individual. Aggression was directed within more than between groups in both species; hamadryas females sometimes targeted females in other groups, however. The results suggest that interactions initiated by hamadryas females may be overlooked as they use more subtle and complex behaviour than do rhesus females. This difference is discussed in relation to the social system.