Subpopulation structure and dispersal in two populations of chamois

Subdivision of a population into reproductive units and rates of exchanges among them may influence population dynamics. Unfortunately, subpopulation units and flows of immigration and emigration are difficult to estimate bec ause of the lack of data on spatial behavior of individuals. By studying tw o populations of chamois (Rupicapra), 244 marked animals, and a 10-year mon itoring program, we determined that subpopulation units were related closel y to topographic limits in which >90% of the females were philopatric. Male s had a greater tendency to disperse than females, especially before reprod uction, but females did more exploratory movements. We found no difference in sex-specific dispersal rates between sites, despite differences in densi ties and sex-ratio. The relatively high dispersal rate of males and the lac k of effects of sex-ratio and density on dispersal rates support the inbree ding-avoidance hypothesis as a main cause of dispersal. High rates of explo ratory movements, especially among females, indicates that local resource c ompetition within female groups also may play a role. Dispersal patterns ha ve to be explained in the context of possible different motivations between sexes, related to social and spatial segregation. Moreover, we argue for a n effect of topography, which determines where dispersal is possible. Accor dingly, dispersal occurred at a site with continuous connections with favor able habitat. Colonization of new areas from protected reserves is limited by low dispersal rates of females and increasing isolation between favorabl e areas in mountains. Management and conservation policies have to take the se aspects into account to predict distribution of chamois on a large scale and cope with high local densities resulting from female philopatry.