PARENT SESSION
Oral Session #55: Predator - Prey Interactions.
Presiding: R. Dueser
Wednesday, August 7. 8:00 AM to 11:30 AM. Cochise Meeting Room, TCC.

You are what you eat: How prey discriminate among predator diets.

SCHOEPPNER, NANCY^*,1, RELYEA, RICK¹, ¹ University of Pittsburgh, Pittsburgh, PA

ABSTRACT- The evolution of predator-induced plasticity requires reliable environmental cues that convey information about predation risk. Many aquatic organisms rely on chemical cues (produced during predation events) for making phenotypic decisions and these cues differ when predators consume different prey diets. It has been hypothesized that prey should exhibit strong anti-predator responses when predators consume closely-related species but weak responses when predators consume distantly-related species(termed the "phylogenetic hypothesis"). However, tests of this hypothesis typically only include the extreme end points–predators eating prey from the same species or prey from a different phylum. We reared three tadpole species (Hyla versicolor, Rana sylvatica, and Rana catesbeiana) in the presence of caged dragonflies (Anax junius) fed one of ten diets and quantified tadpole activity. The diets spanned a range of phylogenetic relatedness to include different species, different genera, different families, different orders, and different phyla. We found that while all three tadpole species could discriminate among predator diets, there was poor support for the phylogenetic hypothesis. The more distantly-related diets did not consistently produce weaker responses than the more closely-related diets in the target species. These results suggest that the chemical cues released during the predation event provides specific information about the species being consumed and that the recognition of this signal by other species is not determined solely by phylogenetic relatedness.

KEY WORDS: predator-induced plasticity, chemical cues, tadpole