Effects of Prior Exposure to Predatory Chemical Cues on Territorial and Foraging Behaviors of the Ozark Zigzag Salamander, Plethodon Angusticlavius
Detection of chemical cues is important for avoidance of predation for many prey animals. Previous experiments have shown that Ozark zigzag salamanders (Plethodon angusticlavius) make behavioral changes when in direct contact with predatory chemical cues. I predicted that prior exposure to a predator cue would also affect the subsequent behavior of these salamanders. I collected chemical cues from ringneck snakes (Diadophis punctatus) which are known predators of these salamanders. Salamanders were exposed to either the predator cue or a blank control for 5 min, then returned to their home Petri dishes and observed. Salamanders exposed to snake cues showed significant changes in activity, including an increase in time spent in escape behavior. These results suggest that salamanders avoid areas where they have had previous encounters with predators. In a second experiment, the effects of prior exposure to predator cues on territoriality were tested. After 5 min of exposure to either the snake cue or blank control, salamanders were returned to either their home chamber alongside an intruding salamander or they were introduced into the home chamber of a resident. Territorial behaviors were recorded for 15 min. Resident salamanders tended to be more aggressive than intruders. Residents previously exposed to snake cues increased chemosensory sampling behavior (nose taps), while the opposite trend was observed for intruders. Additionally, residents whose opponents were exposed to snake cues increased the frequency of Walk Under, a specific aggressive behavior, while intruders with predator-exposed opponents decreased the frequency of Walk Under events.
chemical cues, foraging, territoriality, predation, antipredator, Ozark zigzag salamander, Plethodon angusticlavius, Biology
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