The relationship between breeding by the gopher frog, Rana capito (Amphibia : Ranidae) and rainfall

摘要

Declines in amphibian species have become a worldwide concern. This concern is heightened by predicted global climatic changes that may result in shifts in current patterns of local precipitation. Because of the potential dependence of successful breeding by amphibians on rainfall patterns, we tested the relationship between breeding by the rare gopher frog (Rana capito) and rainfall. We used data collected from long-term (1988-2000) monitoring of breeding activity at two ponds (one ephemeral, one semi-permanent) located in the Lower Coastal Plain of Alabama. Egg-mass counts at both ponds showed a significant positive relationship between reproductive effort and rainfall during the breeding season. Individuals of X capito disperse for considerable distances across a xeric landscape and wet conditions allow greater access to breeding sites for more distantly dispersed frogs. We did not find a significant trend in the number of egg masses laid over time at the ephemeral pond; however, there was a significant increase in egg masses deposited at the semipermanent pond during the course of this study. Understanding the importance of environmental variables such as rainfall will hopefully lead to the successful conservation of this and other species of amphibians with similar environmental requirements.