Genetic diversity and structure in two spotted hyena populations reflects social organization and male dispersal

Populations of large carnivores are particularly vulnerable to demographic changes that can reduce genetic diversity and threaten the persistence of these species. Although the spotted hyena Crocuta crocuta is the most abundant large carnivore in Africa, it has been extirpated locally from many areas. In this study, we compare genetic diversity, patterns of relatedness and genetic structure in spotted hyenas, in order to investigate whether social structure and male dispersal patterns may serve to buffer this species from potential losses of genetic diversity. Using 10 microsatellite markers, we compared two Kenyan populations of spotted hyenas that have experienced different recent population histories. The Masai Mara population has remained large and stable, whereas the Amboseli population has recently recovered from a demographic bottleneck. Despite these historical differences, we found no difference in genetic diversity between the two populations (H-O, Mara: 0.598 +/- 0.060; Amboseli: 0.577 +/- 0.071; P = 0.76). Patterns of relatedness within and between clans were similar in both populations, except that immigrant males appeared to be more closely related to one another in Amboseli than in the Mara. This difference in relatedness among immigrant males appears to reflect differences between populations in patterns of immigration. Hierarchical analysis of the population genetic structure revealed significant genetic differentiation among spotted hyena clans within populations (F-SC = 0.055, F-ST = 0.108) and among spotted hyena study populations (F-CT = 0.057). We suggest that behavioral traits of the spotted hyena, particularly the predominance of male dispersal, were important in the maintenance of genetic variation in the Amboseli population.