Meeting Abstract
Amphibian populations that occur in degraded habitats, such as those in intensively cultivated agricultural regions, are challenged by a complex set of environmental factors. Effective management of land-use to protect sensitive and declining amphibian species requires an understanding of the relative impact of these factors on individual and population success. In the current study, adult American bullfrogs (Lithobates catesbeianus) and Northern leopard frogs (Lithobates pipiens), were exposed to a mixture of agrochemicals for 12 days. The American bullfrog is an invasive species with relatively stable populations in California, USA, while the Northern leopard frog is native to California but has experienced dramatic population declines at nearly all historic locations within the state. The agrochemical mixture represented commonly applied pesticides and fertilizers in California, to which both native and invasive species inhabiting the agricultural environment are likely exposed. Following exposure, select endocrine and immune responses were examined in both species. Native declining Northern leopard frogs responded similar to invasive stable American bullfrogs to the specific chemical mixture tested here. Plasma corticosterone, blood cell differentials, and blood cell activity were not significantly altered in either species. Given the ubiquitous presence of aquatic contamination and the importance of disease in amphibian declines, the current study may assist in addressing the relevance of interspecific and life stage sensitivity to agrochemical exposure.
