Dispersal in sub-Saharan baboons.

In most mammalian species, males tend to leave their natal group and disperse farther than females, while females tend to be philopatric. Primates generally follow this rule, although long-term studies of a variety of species are revealing an increasing number of exceptions. This paper reviews dispersal patterns in 3 subspecies of savanna baboons (Papio cynocephalus cynocephalus, P. cynocephalus anubis, P. cynocephalus ursinus) which exhibit very similar patterns of social organization. Males usually disperse from the natal group at 8-10 years of age. Female dispersal is rare but well documented. Inbreeding avoidance as well as enhanced mating opportunities are suggested as ultimate causes of dispersal. Several proximate factors implicated in the timing of dispersal events are also reviewed.