Ontogeny of play behavior in free-ranging rhesus macaques (Macaca mulatta)
Self and social play of 29 rhesus monkeys were observed in a free-ranging group situation for 6 months. Subjects of various age-sex classes were observed by focal animal and one-zero sampling. Frequencies for 5 categories of play were analyzed in a 3 way factorial analysis of variance. Age and frequencies of play were found to be inversely related. Analysis also revealed that except during infancy, females played more than male subjects. Among categories, self play and non-contact mutual play were dominant forms than those involving physical contact of either or both partners. However, it was also influenced by age, as the preference shifts from self play to non-contact mutual play in a developmental perspective. Among adult monkeys, the occurrence of play was least. Obtained results have been interpreted in terms of ontogenetic and situational variables. Rhesus monkeys preferred peers in social play than youngers and elders. However, adolescent/subadult and adult animals played with younger animals.
Rajbir Singh1 2