Patterns of space utilization and group interactions among free-rangingMacaca mulatta

Abstract

Patterns of space utilization and group interactions were studied using four social bands of free-ranging rhesus macaques at La Parguera, Puerto Rico. There were 0.26 group interactions/hr. of observation; 90% of the observed encounters occurred at feeder stations. Nineteen percent of the interactions involved actual fighting between monkeys from opposing social bands, 58% involved visual and/or vocal threats, 20% were group displacements without aggression and on 3% of the occasions the two groups mixed amicably. Group size was an important factor affecting both the dominance position of the social group and the group's use of space; larger groups were dominant, moved freely about the island, and used less of the total space than smaller lower-ranking troops. Smaller troops were continually forced to move about the island. A new troop of intermediate size added to the island colony provided an experimental test and validated these conclusions regarding group size, dominance and use of space. Patterns of space utilization for each group shifted seasonally, annually, and possibly in response to the addition of the new social troop.