Meeting Abstract

P2.5  Sunday, Jan. 5 15:30  Effect of fish species and size on the antipredator behavior of the San Marcos salamander (Eurycea nana) DAVIS, D.R.*; EPP, K.J.; University of South Dakota; Ottawa University drewrdavis@gmail.com

Prey individuals must constantly balance the time allocation demands of predator avoidance and foraging or mating. To improve efficiency, prey may adjust the intensity of antipredator responses according to the perceived risk posed by a predator, responding less intensely to predators that it perceives as less dangerous. Prey from habitats with diverse predator communities can exhibit sophisticated threat-sensitivity and highly plastic predator responses. We tested whether adults of the San Marcos salamander (Eurycea nana), an aquatic species that encounters a diverse array of fish predators, responded in a threat-sensitive manner to the chemical stimuli of large and small, high-risk (green sunfish) and low-risk (black-tail shiner) predators. We found significant effects of both predator species and predator size, and no effect interaction. As expected, salamanders responded (reduced activity) more intensely to sunfish than to shiners; however, they also responded more intensely to small, gape-limited fish than to larger individuals. Given the capacity for plasticity in these salamanders, the seemingly excessive response to gape-limited predators may represent an ontogenetic holdover resulting from a lifetime in captivity. Alternatively, responses might reflect historical ecological relationships, which may have changed with more recent anthropogenic habitat alterations.