POPULATION-LEVEL AND COMMUNITY-LEVEL ANALYSES OF SPECIES OCCURRENCES OF CENTRAL AMAZONIAN RAIN-FOREST TADPOLES

In this paper I examine occurrence patterns and habitat use of a New World tropical tadpole species assemblage from primary tropical terra firme forest. First, I describe phenology of reproduction. I then undertake a population approach to examine abiotic characteristics associated with sites used for reproduction by each species. Finally, analysis at a more general level tests to see if some correlative structure exists at the community level, i.e., do sites with similar tadpole species also have similar abiotic characteristics? A significant correlation would indicate, for example, that sites with similar abiotic characteristics also share species assemblages. Fifty-three independent aquatic sites were sampled across two consecutive rainy seasons (two 9-mo periods). Twenty-five tadpole species were encountered during the entire study. Significant differences existed among four types of habitats (terra firme pools, peccary wallows, streamside pools, and streams), all located within primary undisturbed forest, with respect to abiotic characteristics such as site permanency and mean depth of water. Most of the rainfall was concentrated between December and May, and phenology of reproduction was strongly affected by the rainfall pattern. For each of the 11 most common species, discriminant analyses revealed the major abiotic characteristics that differed between sites used and not used by those species. On a broader scale of analysis, Mantel tests showed no significant correlations among sites in the similarity of their abiotic characteristics and indices of similarity in their tadpole assemblages. There was also no concordance among sites between either type of similarity and actual proximity of locations. These results indicate that although individual species are responding to habitat characteristics and breed in sites having specific attributes, there are no large-scale species assemblages that covary in habitat use.