Meeting Abstract
Small slow-moving animals such as the American Toad often experience high mortality during dispersal and can be prevented from populating suitable habitats in urban areas due to roads and established predators. Our goal was to introduce marked toads to an urban park with a man-made pond and test to see if there were carryover effects of larval environment on adult translocation success. We manipulated tadpole density (10 or 29 tadpoles/tank) and hydroperiod (60, 75 or 90 days) in the lab to increase phenotypic variation and maximize introduction success. We predicted that toads raised in relatively low density would have larger body sizes. Relatively short hydroperiod was predicted to produce metamorphosis sooner, resulting in reduced body size and jumping performance, however it produced larger snout-vent (SVL) and tibiofibula (leg) lengths. As expected, lower density toads had higher mass relative to SVL (ANOVA, p>.0001). Leg length was significantly affected by hydroperiod (ANOVA, p=.02), density (ANOVA, p<.0001), and their interaction (ANOVA, p=.14). Jump distance was significantly affected by leg length (ANOVA, p=.013), hydroperiod (ANOVA, p=.04), density (ANOVA, p<.0001), but not in their interaction (ANOVA, p=.20). Age at metamorphosis decreased jumping distance (ANOVA, p=.04). Manipulating larval environments may increase the range of phenotypic variation that selection can act on during translocation. However this is a high risk and high effort strategy when coupled with experimental research because it results in low survival in degraded habitats. Despite initially low survival of translocated toads, we hope this strategy to understand the phenotype-environment relationship will eventually help conservation efforts in urbanized environments.
