Long-term ecological research studies are rare and invaluable resources, particularly when they are as thoroughly documented as the Mahale Mountain Chimpanzee Project in Tanzania. Directed by Toshisada Nishida from 1965 until 2011, the project continues to yield new and fascinating findings about our closest neighbour species. In a fitting tribute to Nishida's contribution to science, this book brings together fifty years of research into one encyclopaedic volume. Alongside previously unpublished data, the editors include new translations of Japanese writings throughout the book to bring previously inaccessible work to non-Japanese speakers. The history and ecology of the site, chimpanzee behaviour and biology, and ecological management are all addressed through firsthand accounts by Mahale researchers. The authors highlight long-term changes in behaviour, where possible, and draw comparisons with other chimpanzee sites across Africa to provide an integrative view of chimpanzee research today.