INTRAGROUP COHESION AND INTERGROUP HOSTILITY - THE RELATION BETWEEN GROOMING DISTRIBUTIONS AND INTERGROUP COMPETITION AMONG FEMALE PRIMATES

In some primate species, females interact affinitively with many related and unrelated females, whereas in other species females interact with only a small subset of available partners. One explanation for high rates of affinitive interactions among female members of the same group is that they function to maintain the group's cohesion in competition for resources against other groups. Here, I attempt to determine if grooming is more "egalitarian" or diverse in groups that compete aggressively with their neighbors than in groups in which females rarely take an active role in between-group competition. Three types of data are considered. The first concerns grooming and intergroup encounters in one population of free-ranging vervet monkeys. The second concerns grooming interactions in a captive population of vervets before and after females in adjacent cages began to respond aggressively to one another. The third involves a literature survey of a variety of species. When only female-bonded species are considered, there is no relation between the diversity of grooming within groups and female participation in intergroup encounters. There also appears to be no clear relation between the strength of the female dominance hierarchy and the diversity of grooming among females. Female-bonded groups are apparently composed of subgroups allied in a loose confederation against other groups. Female members of the same group may compete against other groups as a cohesive unit, but their grooming relationships are often sharply differentiated.