SREL Reprint #2952

Predictors of Winter Anuran Calling Activity in the North Carolina Piedmont

Michelle S. Kirlin, Michelle M. Gooch, Steven J. Price, and Michael E. Dorcas

Department of Biology, Davidson College, Davidson, NC 28035-7118

Abstract: Recent global amphibian declines have created an urgent need to monitor their populations. Anuran calling surveys are a widely used and accepted monitoring technique; however habitat and weather variables influence anuran breeding distribution and timing and need to be considered when establishing monitoring efforts. The effects of both habitat and weather variables on detection probabilities and site occupancy estimates of winter-breeding anurans were studied in the western Piedmont of North Carolina. Calling surveys were conducted at 27 ponds in Mecklenburg County, NC and the program PRESENCE was used to evaluate how anuran detectability and site occupancy estimates were influenced by habitat type and weather variables. The best-fit model for each of the three species observed was determined. Upland chorus frog (Pseudacris feriarum) calling activity was best predicted by distance to nearest road and air temperature, spring peeper (Pseudacris crucifer) calling activity was best predicted by precipitation, and southern leopard frog (Rana sphenocephala) calling activity was best predicted by day of the year. Our results indicate that species’ calling activities vary greatly in their associations with different habitat and weather variables. Models that incorporate these variables to describe anuran calling behavior can be used by monitoring programs to design species-specific survey protocols.

Keywords: Amphibian Monitoring; PRESENCE; Occupancy; Calling Survey; Pseudacris feriarum; Pseudacris crucifer; Rana sphenocephala

SREL Reprint #2952

Kirlin, M. S., M. M. Gooch, S. J. Price, and M. E. Dorcas. 2006. Predictors of Winter Anuran Calling Activity in the North Carolina Piedmont. Journal of the North Carolina Academy of Science 122(1): 10-18.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).