The editors of this volume are all experienced primatologists. Vernon Reynolds studied chimpanzees in the Budongo Forest, Uganda, in 1962, and wrote his first book about that experience. He subsequently returned to found the Budongo Forest Project in 1990. This highly successful project continues today. Recently Prof Reynolds published a definitive volume about the Budongo Forest chimpanzees: The Chimpanzees of the Budongo Forest, published by Oxford University Press in 2005. James Paterson had a long career as a primatologist at the University of Calgary, and specialized in the study of baboons and other monkeys. Hugh Notman studied the Sonso chimpanzees in 1996, and then again in 1999 and 2000 when he collected data on pant-hoot vocalizations for his doctoral research. Nicholas Newton-Fisher began studying chimpanzees in the Budongo Forest in 1994, his doctoral research on the relationships of adult male chimpanzees - a rather neglected area at that time. He was the first to study the chimpanzees of the Sonso region of the Budongo forest, having first to habituate them to behavioural observation at close quarters, and to being trailed through the forest. His studies of this chimpanzee society has continued to the present day and forms the foundation and framework for research conducted by others on these chimpanzees. He has published numerous articles on the behaviour and ecology of these chimpanzees, and, in collaboration with others including Vernon Reynolds, his research has provided a deep understanding of this unique community. His current interest is in the use of aggression by male chimpanzees to coerce females' mating behaviour, and the strategies used by females to counter such aggression. He has discovered vigorous retaliation by females against male aggression, including females forming coalitions to respond to males, a behaviour otherwise unreported in wild chimpanzees.