A recurrent theme in community ecology is that interspecific competition greatly influences the distributions and abundances of vertebrate species in communities, and that such competition can lead to extinctions of populations. Terrestrial salamanders have been extensively studies to test theories about competition, and interspecific competition appears to be intense among many species. In eastern North America, widely distributed and abundant species appear to be strong competitors. Weaker competitors appear to have limited distributions and many such species are listed as threatened or endangered. This research will examine the possibility of competitive interactions (particularly interspecific territoriality) between seven species pairs of terrestrial salamanders. Experiments in natural habitats will test hypotheses about intra- and interspecific competition for space, and competitive release experiments will test hypotheses concerning the intensity of competition. Laboratory experiments will test hypotheses about intra- and interspecific combat tactics during aggressive encounters, pheromonal communication, and capturing of food resources. %%% In the eastern US, one widely distributed species interfaces with three geographically isolated species. The three isolated species are considered to be extinction prone as a consequence of severe interspecific competition for territories from the widely distributed species. This research will provide valuable field and laboratory experiments that will provide vital evidence regarding factors leading to the frequently observed population decline of amphibians, in general, and several species a salamanders, in particular.
