Chimpanzees communicate with conspecifics by facial expression, posture, gesture, locomotion, vocalisation, and odour. Here, I do not dwell on detailed description of various types of communication. Interested readers will find useful definitions in various published books and papers, as well as some relevant descriptions in each chapter of this book.

Local differences in tool-use among chimpanzee populations are well-known (see Chapter 2). Here I highlight local differences in patterns of social behaviour, the remarkable differences in communication from subtle gestures to more obvious patterns of courtship and vocal communication. Studies on the chimpanzees of Mahale have contributed much to the development of research on local differences of social behaviour.