FORAGING AND RANGING PATTERNS IN WHITE-BELLIED SPIDER MONKEYS

Ranging and foraging patterns observed during a field study of the beh avioral ecology of Ateles belzebuth belzebuth are analysed in the cont ext of temporal and spatial variation in the distribution of plant res ources at the study site, The study group exhibited two basic patterns of foraging behaviour and habitat exploitation, which appeared to cor relate with the observed variation in resource availability. During th e dry season, when the relative abundance of fruit decreased, the spid er monkeys ranged over a smaller area, repeatedly visiting a few inten sively used fruiting and sleeping trees. As fruit abundance increased during the course of the wet season, the study group expanded its rang e, and both the daily path length and the number of fruiting trees vis ited increased daily. These patterns are analysed and evaluated in rel ation to foraging strategies.