Comparative Studies of Gregariousness and Social Structure Among Seven Feral Macaca fuscata Groups

Abstract

Group differences in gregariousness and social structure among various feral groups of Japanese monkeys have been reported in field studies of provisioned monkeys, which began in the 1950s (Kawamura 1966, Kawai 1969, Yamada 1966, 1971). These reports, however, have been mostly based on intuitive and subjective impressions, such as “more vs less cohesive group”, or “group strictly vs loosely controlled by the leader”. The reported group differences were attributed to differences between leaders’ characters or to the differentiation of the social roles of group members in relation to their age and sex. The first purpose of this study is to demonstrate group differences in gregariousness by applying uniformly controlled experimental methods. The second purpose is to discuss the social structure of Japanese monkeys with respect to group differences in their gregariousness.