CHEMICAL ALARM SIGNALING IN TERRESTRIAL SALAMANDERS - INTRASPECIFIC AND INTERSPECIFIC RESPONSES

Chemical alarm cues are known to be important in mediating predator av oidance in a variety of taxonomic groups. The purpose of this study wa s to rest whether three species of salamanders that co-occur in the co astal mountains of Oregon utilize chemical alarm cues in predator avoi dance. In laboratory experiments, Western redback salamanders, Plethod on vebiculum, and Southern torrent salamanders, Rhyacotriton variegatu s, exhibited an avoidance response to stimuli from injured conspecific s, while Dunn's salamanders, Plethodon dunni did not. Additional exper iments demonstrated interspecific alarm responses. P. vehiculum and R. variegatus responded to each other's alarm cues bur did not respond t o the alarm cues of allotopic long-toed salamanders, Ambystoma macroda ctylum. For R. variegatus this is despite the fact that they are more closely related to the allotopic species (A. macrodactylum) than to th e syntopic species (P. vebiculum). Thus phylogeny alone may not explai n patterns of cross-species alarm responses. Instead, interspecific al arm responses may occur between syntopic species that belong to the sa me prey guild (i.e. those species that co-occur spatially and temporal ly and are exposed to the same suite of predators).