MCCOY, Michael W*; BOLKER, Ben; OSENBERG, Craig; University of Florida; University of Florida; University of Florida: Predator induced phenotypic plasticity: influence of prey size, density, and experience

Adaptive phenotypic plasticity in response to predators has been documented for many organisms. However, most studies have only examined the phenotypic responses of organisms of a single size class and density in the presence of a particular (usually large) predator. Few studies examine predator induced phenotypic changes and their affects on predator-prey interactions for prey and predators of different sizes or at different densities. For example, prey may exhibit different phenotypic responses to a gape limited predator than to a non-gape limited predator. In this study, we determined how induced defenses, prey density, prey size and predator size interact to affect prey survival. Specifically we exposed treefrog (Hyla squirrella) tadpoles to small gape limited (Pachydiplax longipennis) and large non-gape limited (Tramea carolina) invertebrate predators to examine how the functional responses of these predators change with prey size and the prey�s prior experience with each predator. We found that both size and prior predator experience affect tadpole survival. Tadpoles survived better when exposed to a familiar predator than when introduced to a novel predator. We also report on a suite of predator specific phenotypic responses including a variety of behavioral metrics, growth rates, developmental rates, and morphology. In addition, we report on among individual variation in phenotypic responses. Integrating multiple phenotypic responses (both among individuals and populations) and assays of performance (i.e. survival) in the presence of different predators is critical for understanding how phenotypic plasticity influences the outcome of species interactions.