Initial dyadic social behavior in free-ranging rhesus monkeys (Macaca mulatta)
Initial dyadic social interactions of 13 rhesus monkeys were observed in a free-ranging group of 26 members. Each subject was observed for 900 intervals of 20 sec each by focal animal method. The obtained matrix of approach interactions was separately analyzed in relation to sex and dominance level of interacting animals. Dominance ranks were determined by approach-withdrawal scores and its validity was assessed with other submissive scores. Chi-square analysis revealed a significant preference for opposite sexed animals. High ranked animals initiated more social interactions than was expected; however, other animals approached less towards them. It is concluded that in free-ranging group situations, members do not interact at random, rather their interactions are patterned by individual characteristics, such as age, sex and relative dominance level in the group hierarchy.