A major goal in community ecology is to identify mechanisms that govern the assembly and maintenance of ecological communities. Current models of metacommunity dynamics differ chiefly in the relative emphasis placed on dispersal limitation and niche differentiation as causal mechanisms structuring ecological communities. Here we investigate the relative roles of these two mechanisms in structuring 124 tropical forest primate communities in Africa, South America, Madagascar and Borneo. We hypothesized that if dispersal limitation is important in structuring communities, then community similarity should depend on geographic proximity (controlling for ecological similarity). Conversely, if communities are assembled primarily through niche processes, then community similarity should be determined by ecological similarity (controlling for geographic proximity). We performed Mantel and partial Mantel tests to investigate correlations between primate community similarity, ecological distance and geographic distance.
Results showed significant and strongly negative relationships between diurnal primate community similarity and both ecological similarity and geographic distance in Madagascar, but significant and stronger negative relationships between community similarity and geographic distance in African, South American and Bornean metacommunities. These results support the hypothesis that dispersal limitation structures primate metacommunities in all four biogeographical regions. We conclude that dispersal limitation is an important determinant of primate community structure and may play a stronger role in shaping the structure of some terrestrial vertebrate communities than species sorting along environmental gradients.