Affiliative Behaviour Between Adult Males of the Genus Macaca

Abstract

Abstract1. Relations between sexually mature males in multi-male groups of macaques have been characterised as largely antagonistic, with bonnet macaques being the only frequently cited exception. A survey of the literature indicated that affiliative behaviour between males is more widespread than has been supposed. 2. Factors were examined which may influence the nature of relations between adult males. In all macaque species for which there are adequate data, males commonly move between groups, making it unlikely that kinship between adult males is an important factor in natural groups. 3. Affiliative behaviour between adult males is more frequently observed in small groups, with sex ratios closer to parity, than in large groups with more uneven sex ratios. Two factors are thought to influence this association. First, most large groups with highly skewed sex ratios were provisioned. Provisioning results in increased levels of aggression and tension, which may preclude the formation of affiliative relationships. Second, in groups with highly skewed sex ratios males can find many potential grooming partners among the females and their offspring. Where the sex ratio is more even there may be a shortage of potential partners among the natal animals, and males may form relationships with other males as an alternative. 4. Much of our knowledge of macaque societies has come from provisioned populations. Findings made under such conditions must be verified with data from natural populations, wherever possible, especially where competition may have an influence on the patterns of behaviours observed.