Relationship Among Wetland Hydroperiod, Presence of Fish and Amphibian Reproductive Characteristics in Depression Wetlands of the Southeast
Joel W. Snodgrass Division of Life Sciences, and Consortium for Risk Evaluation with Stakeholder Participation, Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ; and Savannah River Ecology Laboratory, Aiken, SC
Joanna Burger Division of Life Sciences, and Consortium for Risk Evaluation with Stakeholder Participation (CRESP), Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, NJ
A comparative framework for predicting the response of amphibian species to the introduction of fish would be useful to managers. Because life-history traits are the fundamental determinants of population persistence and restrict the occurrence of amphibian species along the gradient from ephemeral wetlands to permanent ponds (hydroperiod gradient), life-history traits are a logical choice for constructing a comparative framework. We concentrated on life history characteristics of early life stages (i.e., eggs and larva). We used data on the relative densities of larva of 20 amphibian species among 22 Southeastern depression wetlands to identify species preferences along the hydroperiod gradient. We then correlated early life stage characteristics of species with their hydroperiod preference. Among anurans and caudates (13 and 7 species, respectively) there was a general increase in egg size, clutch size, duration of larval period, size at metamorphosis and adult size from short hydroperiod wetlands to long hydroperiod wetlands. However, two anuran species (Acris crepitans and A. gryllus) which preferred long hydroperiod wetlands with fish had characteristics similar to anuran species preferring short hydroperiod wetlands. Our results suggest that species with relatively small eggs, clutches, size at metamorphosis and adult size, and short larval periods will be particularly impacted by fish introductions.
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