Outcast males and social structure among bonnet macaques (Macaca radiata)



Outcast males are a regular feature of rhesus (Macaca mulatta) and Japanese (M. fuscata) macaque societies but are rare among bonnet macaques (M. radiata). Apparently bonnets have other solutions than ostracism for their social problems. For example, in many troops the male-female ratio ranges from 0.7−1.0+; and, as the young adult males grow to full social and physical maturity, they remain in the troop and participate actively in social relationships. A few troops of bonnet macaques, however, have a network of social relationships which prevents the young males from being integrated into the social system; in some of these cases, male isolation occurs. A comparison of the social relations between males in bonnet macaque societies of both types suggests that societies with strong male-male bonds accommodate their growing males better than those with highly individual males.