Meeting Abstract
Many prey animals use olfactory cues for predator detection and will change their behavior to avoid the predator. The olfactory cues released by predators are unique mixtures of chemicals that are determined by the species of the predator, the predator’s physical condition and diet. Some prey species can differentiate changes in the diet of the predator which may alter the prey’s antipredator response. If different predator dietary cues lead to shifts in the foraging behavior of prey, then changes in predator diet could have indirect effects on the species on which prey forage. A tri-trophic interaction involving Micropterus salmoides, Faxonius rusticus, and three species of freshwater macrophytes (Myriophyllum exalbescens, Elodea canadensis, & Chara spp.) was used to test the hypothesis that differences in the diets of predatory fish can change crayfish foraging behavior and produce indirect effects in macrophyte communities. The predatory M. salmoides were fed four different diets consisting of commercial fish food, F. virilis crayfish, F. propinquus crayfish, and F. rusticus crayfish. Four F. rusticus were then placed into mesocosms with samples of each plant species and were allowed to feed while being exposed to odors from different predator diet treatments. The crayfish showed significant differences in plant consumption across the various predator diets. Different predator diets also changed the foraging preferences of the crayfish, causing them to feed selectively on different plant species depending on the predator diet treatment applied. These results demonstrate that prey animals are sensitive to predator dietary cues and that these cues can mediate indirect effects of predators on other species in aquatic communities.
