Detecting danger from prey-guild members: behavioural and metabolic responses of Ozark zigzag salamanders to alarm secretions from earthworms


When different species have common predators, selection should favor individuals that respond to alarm cues from the other species. The Ozark zigzag salamander (Plethodon angusticlavius) occupies microhabitats under rocks and logs during wet conditions, and uses subterranean burrows during harsh environmental periods. Using the vomeronasal organ, these salamanders can assess chemical cues in their environment, including cues from predators and alarm secretions from conspecific and heterospecific salamanders. Ozark zigzag salamanders live syntopically with earthworms which are abundant and vulnerable to the same predators. We tested whether salamanders would respond to alarm secretion from earthworms in ways that are consistent with antipredator behaviour. We obtained alarm secretions from earthworms by simulating a predator attack (grasping them with forceps) and collecting the stimuli in water. When exposed to alarm secretions, salamanders increased their time spent in escape behaviour, decreased their chemosensory behaviour, and increased oxygen consumption, whereas their responses to stimuli from unstressed earthworms were similar to their responses to blank water. Our results suggest that Ozark zigzag salamanders recognize alarm secretions from earthworms as dangerous because of their ecological similarity.



Document Type





Ozark zigzag salamander, Plethodon angusticlavius, prey guild, alarm secretion, earthworm, predation risk

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Journal Title

Ethology Ecology & Evolution