Scramble and Contest in Feeding Competition Among Female Long-Tailed Macaques (Macaca Fascicularis)

Abstract

AbstractMost previous studies of feeding competition in gregarious primates compared some average or group-level characteristic over a range of group sizes. Here an attempt is made to separate the effects of within-group scramble (the "group size" effect) and of within-group contest (the "dominance" effect) on energy expenditure and food intake in female long-tailed macaques (Macaca fascicularis). Significant or consistent scramble and contest components were demonstrated for locomotion and energy expenditure, for the presence in the main party of the group, and for birth rate. The intake of fruit or animal matter was not increased in compensation, but the intake of dispersed vegetable matter probably was. It is concluded that both components of feeding competition exist in long-tailed macaques, but that contest for food is often transferred into contest for safety. A framework is proposed to relate interspecific variation in contest effects to food distribution and group cohesion.