The Effects of Pond Drying and Predation on Blanchard's Cricket Frogs (Acris blanchardi)

Pond hydroperiod and predators play a central role in structuring aquatic communities. Because of predicted changes in precipitation and temperature patterns associated with climate change, pond hydroperiods will likely be altered. Reduced hydroperiods can impact amphibian populations by restricting the amount of time available for larval growth and by altering predatory interactions via increased predator densities. We investigated how pond drying and predation singularly and interactively affected growth and survival of Acris blanchardi (Blanchard's Cricket Frogs). We reared recently hatched tadpoles through metamorphosis in outdoor mesocosms using a factorial design incorporating three hydroperiods (fast-drying, slow-drying, or constant) and three larval odonate predator treatments (caged, uncaged, or absent). Caged and uncaged predator treatments were implemented to evaluate both consumptive and non-consumptive effects. There were no differences in survival, time to metamorphosis, or size at metamorphosis in response to drying or predation treatments. Although pond drying rates in this study did not induce measurable responses, it is possible that more extreme conditions could impact metamorphosis. The lack of response to odonate predator presence and cues suggests tadpoles of A. blanchardi may rely on other behavioral and phenotypic defenses, such as the tail spot, to escape predation. Developing a more comprehensive understanding of how A. blanchardi responds to altered hydroperiod, predators, and their potential interactions is important to predict how this species and other amphibians that breed in diverse aquatic habitats may respond to the influence of climate change on aquatic ecosystems.