For the past three decades the mountain gorillas of Karisoke Research Center have been the subject of many studies focusing on their behaviour and ecology. Long-term observations on known individuals, from birth to death, and data on social behaviour within and between groups have led to an understanding of many aspects of gorilla social structure. The findings have made significant contributions to models of comparative primate behavioural ecology. Mountain gorillas have also been the focus of intense conservation efforts, which have become a model for conservation programs elsewhere. While most research has focused on mountain gorillas, data on the other two recognised subspecies have increased over the past twenty years. This book highlights and summarises some of the behavioural, ecological and conservation work on mountain gorillas, and makes comparisons with findings from other study sites. It represents the most up-to-date and diverse collection of information available on this endangered ape.