1Graduate Group in Ecology, University of California, Davis, 2Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation, University of Kent, 3School of Biological and Chemical Sciences, Queen Mary University of London, 4People & Nature Consulting International, Indonesia, 5School of Biological Sciences, University of Queensland, 6Basilornis Consults, Netherlands, 7Department of Anthropology, University of California, Davis, 8Animal Behavior Graduate Group, University of California, Davis
Thursday 2:15-2:30, Galleria South
A central issue in community ecology is assessing the role of deterministic processes, such as niche differentiation, in structuring communities. In this study, we investigate to what extent multiple community assembly hypotheses consistent with competition causing niche differentiation are supported. We focus on vertebrate communities on the island of Borneo, where we predict that patterns consistent with interspecific competition structuring communities will be more apparent when non-primate competitors of primates are included. Because primate communities are frequently viewed as self-contained research concerning the factors that determine their structure is most often limited to the primate community in isolation. However, if competition for food resources is more severe between primates and non-primates than among primates, then the effects of niche differentiation on community structure may be masked if primates are studied in isolation; any signal of competition may appear weaker due to the exclusion of non-primate competitors. We therefore test the implicit assumption from previous research in primate ecology by examining whether primates in Borneo compete predominantly with other primates or with other vertebrates, particularly birds, bats and squirrels. Specifically, we test for checkerboard distributions, guild proportionality, Fox’s assembly rule for favored states and nestedness. We found strong support for patterns consistent with interspecific competition structuring communities, particularly when taxonomic groups were combined. These results demonstrate the presence of significant ecological structure and are consistent with the interpretation that competitive interactions within and between these taxonomic groups may have shaped the species composition in these communities.
This study was supported by a National Science Foundation Graduate Research Fellowship to LB.