Date of Award
Open Access Thesis
Master of Science (MS)
Cy L. Mott
Valerie E. Peters
Consumptive (direct) effects of predation have been well-studied in most aquatic systems, but non-consumptive (indirect) effects on prey have only recently received limited attention in some groups. As aquatic consumers, tadpoles have traditionally been considered strict herbivores, leaving their predatory impacts via consumptive and non-consumptive interactions on aquatic invertebrates largely unexplored. The objectives of this study were to quantify omnivory among wood frog (Lithobates sylvaticus) tadpoles, determine their consumptive and non-consumptive effects on invertebrate communities, and investigate whether such effects are mediated by habitat shading and tadpole body size. Lithobates sylvaticus tadpoles and egg masses were randomly sampled from 11 ponds in the Daniel Boone National Forest, eastern Kentucky, USA. Tadpoles were dissected to quantify the frequency of omnivory, while egg masses were reared to hatching to create size structure. Hatched tadpoles were then employed in a fully factorial mesocosm design that manipulated tadpole presence (absent, caged, or free-swimming), body size (large or small), and canopy cover (shaded or unshaded) to determine effects on invertebrate communities. Over 70% of tadpoles in natural ponds engaged in omnivory, primarily on zooplankton. Tadpoles in mesocosms exhibited consumptive and non-consumptive effects on invertebrate communities, with generally reduced invertebrate abundance under shaded conditions and in the presence of larger tadpoles. Larger tadpoles in unshaded conditions also exhibited higher survival and maintained larger sizes, but smaller tadpoles in unshaded conditions grew more quickly. This study stresses the ecological importance of tadpoles, given their roles as predators of, and competitors with, aquatic invertebrates.
Copyright 2022 Brady Patrick Parlato
Parlato, Brady Patrick, "Body Size And Habitat Shading Influence The Consumptive And Non-Consumptive Effects Of Wood Frog (lithobates Sylvaticus) Tadpoles On Aquatic Invertebrate Communities" (2022). Online Theses and Dissertations. 748.