Where We Stand Field workers-scientists of animal (including human!) behavior in nature-have long been fascinated by wild chimpanzees. A person who once has studied wild chimpanzees will be eager to observe them again. A person who has studied them twice will make every effort to continue the study, unless prevented from doing so. In short, behavioral primatology is addictive! Many people, among them Jane Goodall, Richard Wrangham, and I, do not regret that they have dedicated their whole lives to the study of wild chimpanzees. This is because the apes' behavior is always challenging: chimpanzees are cheerful, charming, playful, curious, beautiful, easygoing, generous, tolerant, and trustw- thy most of the time, but also are cautious, cunning, ugly, violent, ferocious, blo- thirsty, greedy, and disloyal at other times. We human beings share both the light and dark sides with our closest living relatives. For decades, we have documented huge across-population variation in behavior, as well as within-population variation. Cultural biology (now called cultural pri- tology), as proposed 60 years ago by Kinji Imanishi, recently has flourished.

Chimpanzees are humanity's closest living relations and are of enduring interest to a range of sciences, from anthropology to zoology. In the West, many know of the pioneering work of Jane Goodall, whose studies of these apes at Gombe in Tanzania are justly famous. Less well-known, but equally important, are the studies carried out by Toshisada Nishida on the eastern shore of Lake Tanganyika. Comparison between the two sites yields both notable similarities and startling contrasts. Nishida has written a comprehensive synthesis of his work on the behaviour and ecology of the chimpanzees of the Mahale Mountains. With topics ranging from individual development to population-specific behavioural patterns, it reveals the complexity of social life, from male struggles for dominant status to female travails in raising offspring. Richly illustrated, the author blends anecdotes with powerful data to explore the fascinating world of the chimpanzees of the lakeshore.

The Great Apes (chimpanzees, bonobos, gorillas and orangutans) are our closest living relatives, sharing a common ancestor only five million years ago. We also share key features such as high intelligence, omnivorous diets, prolonged child-rearing and rich social lives. The Great Apes show a surprising diversity of adaptations, particularly in social life, ranging from the solitary life of orangutans, through patriarchy in gorillas to complex but different social organizations in bonobos and chimpanzees. As Great Apes are so close to humans, comparisons yield essential knowledge for modeling human evolutionary origins. Great Ape Societies provides comprehensive up-to-date syntheses of work on all four species, drawing on decades of international field work, zoo and laboratory studies. It will be essential reading for students and researchers in primatology, anthropology, psychology and human evolution.