Group changing in free-ranging male rhesus monkeys

Abstract

Group changing behavior of maleMacaca mulatta was studied over a six-year period at the rhesus monkey colony on two coastal islands at La Parguera, Puerto Rico. Males first left their natal group at a mean age of 47 months and became solitary for the first time at a mean age of 64 months; all had left their natal groups by seven years of age. Age, mating season, sex ratios of adult males and females in the social bands, and geographical barriers all had significant effects on the group shifting. Population size, rank of mother or being an orphan did not significantly affect the changing process. Two factors, age (size) and seniority in the group, were important in determining a male's rank in his new group.