The chimpanzee population of the Mahale Mountains National Park, on the eastern shore of Lake Tanganyika, has been studied for over 25 years, and is one of the best sites for primate research in the world. This book gives a detailed analysis of this population, including sex and age differences, feeding behaviour and the influence of old age on chimp behaviour, as well as other aspects of their behaviour. Also includes a full bibliography on research done on the group.