Using Well Water to Increase Hydroperiod as a Management Option for Pond-Breeding Amphibians

Abstract

Drying of wetlands before the completion of larval development is a major factor controlling reproductive success of amphibians breeding in temporary ponds. For some endangered taxa, such drying can severely limit population viability and species survival. One way of reducing the impact of premature drying is to add water to temporary ponds via an outside source, but data on the value of this strategy are almost nonexistent. We tested whether water from nearby wells could be used to avoid pond drying and increase reproductive success for the endangered dusky gopher frog (Rana sevosa). During a 7-week period in 2001, we added over 366,000 L of water from nearby wells to the breeding site for this frog and were able to increase and maintain water levels until a heavy natural rainfall filled the pond basin. This avoided complete larval mortality and 130 metamorphic frogs were produced, the first successful reproduction since 1998. Our study provides an important initial step in evaluating the use of well water to increase the hydroperiod of breeding ponds for anurans; however, further studies should be undertaken before this method is used as a conservation tool to avoid larval mortality of imperiled amphibians.