Social behavior adaptations of gibbon (Hylobates lar) in a controlled environment

A population of six adolescent—adult gibbons (three males and three females) were observed in a controlled environment in order to assess any social behavior adaptations related to forced aggregation and to a physical environment which differed from the native habitat in that there were no predators, no food scarcity and the geographic range was limited to 1.5 acres. Data on location, size and composition of naturally formed social groupings revealed that certain gibbons avoided social contact with certain others. This observation is discussed in relation toChance's (1967) concept of “attention structure.” It is viewed as representative of a dominance hierarchy serving gibbons as a social behavior adaptation when forced to aggregate.