We conducted behavioral experiments to determine how competition and predation may affect an assemblage of salamanders that meet at and cross forest to aquatic ecotones. At Mountain Lake Biological Station, southwestern Virginia, USA, adults of four abundant species interact at the forest to stream ecotone. Plethodon einereus and the larger P. glutinosus inhabit the forest floor up to the edges of streams while Desmognathus fuscus and Eurycea eirrigera forage from the edges of streams onto the forest floor. Our six laboratory experiments yielded predictions as to how these species affect each others' distributions and abundances in the natural habitats. Previous studies showed that adults of P. cine reus are territorial intraspecifically and toward same-size juveniles of P. glutinosus. In our experiment, territorial residents of P. einereus did not act aggressively toward intruding adults of P. glutinosus and the latter species was neither aggressive nor predatory toward P. einereus. The two species were equally benign in a second experiment when the roles of resident and intruder were reversed. Thus, we predict that the adults of these two species do not influence each others' distributions on the forest floor.