Lemur catta male exchange occurred throughout the reserve at Berenty and affected change in the composition of most, if not all, of the twelve troops in the reserve. Males migrate into troops with which they are already familiar. Inter-troop encounters may serve to increase a male’s knowledge of a potential new home. Extensive overlap in home ranges may facilitate this process. An important result of migration in L. catta is the avoidance of inbreeding in a species whose females form stable groups over long periods of time and do not breed out of their troop.