Fifty-day observation of a free-ranging adult male chimpanzee.

An adult male chimpanzee living in Gombe National Park, Tanzania, was observed for 50 consecutive days during the 1974 dry season, for a total of 563 h. This individual, Figan, was the alpha male of a community of 42 chimpanzees. The composition and size of temporary associations within the community was influenced largely by the presence of one estrus female and by characteristics of the food resources. Figan's daily time budget varied little for travel and grooming, but there were major changes in time spent feeding tha inactive over the 50 days. Predatory behavior occurred periodically and meat was eaten on five occasions. Agonistic and sexual behaviors are discussed relative to Figan's high social status. A cooperative relationship was maintained between Figan and his older brother.