Behavioral Interactions Among Four Species of the Salamander Genus Desmognathus

Four sympatric species: Desmognathus quadramaculatus, D. monticola, D. fucus, and D. ochrophaeus, showed different substrate preferences in experimental trials. In addition, the choices of substrates and of cover objects were influenced by the presence of other salamanders. Significant differences in substrate choice were found for each pair of species. The ratio of rocky to woody substrate chosen was lower for the more terrestrial species. The ecologically intermediate species, D. monticola, exhibited the broadest choice of substrate and shifted its choice when confined with congeners. Adults of D. monticola became more active and avoided the preferred substrate of D. quadramaculatus when confined with that species. Juvenile of D. monticola became less active but also avoided preferred substrates of the larger D. quadramacultatus. In 1—m2 arenas with four cover objects, small individuals of the three more terrestrial species avoided cover occupied of large individuals of these species. No aggressive behavior patterns were observed in 100 encounters of different individuals. These results suggest that this assemblage of salamanders is structured by species—specific microenvironmental preferences that are affected by interspecific interactions. Avoidance of other salamanders is the common response that segregates individuals and species. This is likely an adaptation to the severe risk of predation faced by small salamanders.