SREL Reprint #2372

A comparison of anuran calling patterns at two Carolina bays in South Carolina

Jeffrey R. Mohr and Michael E. Dorcas

Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29801

Abstract: Most male anurans use advertisement calls to attract females during their breeding season. While general breeding seasons are known for many species, temporal details of calling activity within the breeding season have been poorly described. Using an automated recording system, we compared the temporal calling patterns of five species of anurans [Hyla cinerea (green treefrog), H. gratiosa (barking treefrog), Rana catesbeiana (bullfrog), R. clamitans (green or bronze frog), and Acris gryllus (southern cricket frog)] between two different wetlands on the Savannah River Site, South Carolina. We recorded A. gryllus calling at all times during the day at both sites. Treefrogs (H. cinerea and H. gratiosa) called only during the early evening after sunset and R. catesbeiana and R. clamitans called primarily during the early morning hours before sunrise. Intensity was similar between sites for treefrogs and for R. clamitans; however, calling intensity for R. catesbeiana and A. gryllus differed between the two sites. Rana catesbeiana had a higher calling intensity at Flamingo Bay and A. gryllus had a higher calling intensity at Ellenton Bay. Presumably, variation in calling intensities of R. catesbeiana and A. gryllus reflect population size differences between the two wetlands which are likely related to differences in vegetation. Results of this study demonstrate variation in calling activity among species and between similar wetlands. Understanding such variation is essential for studies of anuran reproductive behavior. Additionally, data such as these can be used to optimize manual calling surveys, a major component of most contemporary amphibian monitoring programs.

Keywords: anurans; calling; automated recording system; Carolina Bay

SREL Reprint #2372

Mohr, J.R. and M.E. Dorcas. 1999. A comparison of anuran calling patterns at two Carolina bays in South Carolina. The Journal of the Elisha Mitchell Scientific Society 115: 63-70.

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