Studies on the social behaviour of bonnet monkeys

Abstract

Two troupes of bonnet monkeys (Macaca radiata) occupying a garden sector of Bangalore were studied mainly for their social behaviour and it was found that though in their behaviour, the bonnets comply with the general behavioural patterns characteristic of Primates, there exist a few features and expressions which are different.

Bonnets live in well organised societies near human habitations and feed on wild and cultivated items of food. The troupe size ranges from 10 to 50 members that include males and females of all age groups. No real solitary bonnet has yet been encountered. They occupy definitely demarcated home ranges which overlap those of the others resulting in occasional fights or aggressive behaviour. They roost in many selected quarters, preferably tall and well spread trees (Rahaman & Parthasarathy, 1969). Though bonnets appear to be mostly ground dwellers, their adaptation to arboreal life provides safety. Adult males drop to the rear during flights in danger and see that the rest of the members are safe on tree-tops. They have a communicative system involving gestures, grimaces and calls (Rahaman & Parthasarathy, 1968).

The main breeding period is during the months of October and November. The period of the highest frequency of copulations in rhesus monkey of North India coincides fairly with that of bonnets, suggesting that the seasonal factors, to a considerable extent, control the onset of mating season and consequently the births. Babies are born mostly during the months of February and March. The gestation period appears to be of about 5 months duration. The mother-infant relation is most intimate and pronounced during the first 2 months of the baby's life and there is a gradual fall in this aspect as the baby becomes older.