Journal of Chemical Ecology, Vol. 22, No. 9, 1996 AVOIDANCE RESPONSE OF A TERRESTRIAL SALAMANDER (Ambystoma macrodactylum) TO CHEMICAL ALARM CUES DOUGLAS P. CHIVERS,* JOSEPH M. KIESECKER, MICHAEL T. ANDERSON, ERICA L. WILDY, and ANDREW R. BLAUSTEIN Department of Zoology, Oregon State Universi~ 3029 Cordley Hall, Corvall&, Oregon 97331-2914 (Received December 22, 1995; accepted May 2, 1996) Abstract--Organisms from a wide variety of taxonomic groups possess chem- ical alarm cues that are important in mediating predator avoidance. However, little is known about the presence of such alarm cues in most amphibians. and in particular terrestrial salamanders. In this study we tested whether adult long-toed salamanders (Ambystoma macrodactvlum) showed an avoidance response to stimuli from injured conspecifics. Avoidance of stimuli from injured conspecifics could represent avoidance of a chemical alarm cue or, alternatively, avoidance of a territorial pheromone or conspecific predator odor. Consequently, we also tested whether salamanders avoided stimuli from noninjured conspecifics. Salamanders avoided stimuli from injured but not from noninjured conspecifics. Therefore, we concluded that the response to injured conspecifics represents avoidance of a chemical alarm cue and not avoidance of a territorial pheromone or predator cue. This is the first clear demonstration of chemical alarm signaling by a terrestrial amphibian and the first report of chemical alarm signaling in an ambystomatid salamander. By avoiding an area containing stimuli from injured conspecifics, long-toed sal- amanders may lower their risk of predation by avoiding areas where predators are foraging. Key Words--Alarm pheromone, chemical signaling, predator avoidance, long- toed salamanders, Ambystoma macrodactylum. *To whom correspondence should be addressed. 1709 0098-033119610900-1709509.50/0 O 1996 Plenum Publishing Corporalion