The home range of the Sonso community of chimpanzees from the Budongo Forest, Uganda.

Early studies of chimpanzees in the Budongo Forest, Uganda, reported only rough estimates for home range size. This study aimed to quantify home range size and habitat composition for chimpanzees in this forest, for the Sonso community. Home range is the habitually used portion of the total area over which an animal travels, and for chimpanzees, the home range is shared by the community. From data collected in 1994 and 1995, the home range for this community was estimated to cover an area of 6.78 km2 using the minimum convex polygon analysis technique and 6.89 km2 using fixed kernel analysis. Habitat was highly heterogeneous. The small home range and consequent high local population density (around 6.8 individuals km-1) suggests that the Sonso region is highly productive in chimpanzee foods, possibly in contrast to other parts of the forest. This estimate of home range size is among the smallest reported for habituated chimpanzees but comparisons with other sites are confounded by methodological and analytical differences. Future studies of chimpanzee ranging patterns should endeavour to use precise locations and the latest analytical techniques to ensure accurate estimation of range size and structure, and inter-site comparability.