The effects of perceived mortality risk on habitat selection in a terrestrial salamander

Abstract

Animals select microhabitats based on food availability, physiological cost, and mortality risk relative to other available habitats. The best habitat selection models take into account a trade-off between predation risk and foraging success. We investigated the effect of simulated predation on microhabitat use in light of differences in prey availability in Plethodon cinereus, a small terrestrial salamander which displays nighttime plant-climbing behavior. We tested the hypothesis that plant climbing is a predator avoidance behavior in P. cinereus by causing autotomization of salamanders’ tails to simulate attempted predation and subsequently tracking them with fluorescent powder. We found that, on average, simulated predation increased the maximum height climbed. To ensure that salamanders were not climbing to access greater numbers of prey, we measured prey abundance on and above the ground and found more prey on the ground than on plants. Finally, we conducted observations of unmanipulated individuals of P. cinereus and found that weather variables affected the height climbed and males climbed higher than females, perhaps due to lower energetic costs in males. We conclude that salamanders use the plant habitat as a refuge from predation despite reduced foraging potential and increased physiological cost.