Individual and sex differences in the behavior of adolescents Macaque Rhesus (Macaca mulatta) united into a new social group

Abstract

Introduction. Primates living in groups in the laboratory can exhibit a wide range of behaviors consistent with their natural behavioral repertoire. The study of adolescent macaques’ behavior grouped together in new social group is of interest for understanding the social organization of preschool children, as well as for anthropology in general. The goal of the work is to reveal the individual and sex differences of behavioral activity of unrelated adolescent rhesus monkeys (Macaca mulatta), grouped in new laboratory conditions. Materials and methods. We conducted focal observations recording the behavior activity of each macaque in the first two months of their cohabitation. We analyzed individual and sex differences in the manifestation of locomotor, exploratory and social behavior. Results. Individual characteristics of macaques for each type of behavior were identified. The group turned out to be the most heterogeneous in the degree of manifestation of exploratory behavior. The exploratory activity of females was significantly higher than that of males. Social activity was significantly higher in males due to the predominance of friendly reactions, although aggression was equally demonstrated in both sexes. However, females were significantly more often exposed to aggression from other individuals than they showed it themselves. As for males, aggression towards other individuals and aggression from other individuals did not differ significantly. Most individuals in the group demonstrated more friendliness reactions than aggression, but two macaques showed these types of behavior equally. There were no differences in the number of locomotor reactions between males and females. Conclusion. The analysis made it possible to trace the basic forms of behavioral activity of adolescent macaques in context of the new social group formation. The obtained results give us better understanding of the mechanisms of primates’ social behavior organization.