Cooperative Fish and Wildlife Research Units Program: Arkansas
Education, Research and Technical Assistance for Managing Our Natural Resources

Arkansas Project

Using hydrophones to survey for underwater calling frogs

March 2019 - December 2021


Participating Agencies

  • Arkansas Game and Fish Commission

The first step to wildlife conservation is understanding where species occur and how many individuals are present. For species that vocalize (such as birds and frogs), surveys are relatively straightforward and easy. However, emerging research indicates that some frogs primarily or exclusively call underwater and these vocalizations rarely break the air-water surface and are unlikely to be detected by surveyors. Coincidentally, most frog species that are known to call underwater are threatened or endangered including the Crawfish Frog, Chiricahua Leopard Frog, and Gopher Frog. In partnership with Cornell University and the Army Corps of Engineers, the Arkansas Unit is testing a novel method, using hydrophone recorders, to document the presence, distribution, and abundance of several imperiled frog species that primarily call underwater. We are demonstrating this technology on Fort Stewart, GA, Coronado Natl Forest, AZ, and at Woolsey Wet Prairie, AR. If an efficient and cost-effective methodology can be established, we will provide an innovative and important new tool for the military and other land managers to survey for and conserve these imperiled species.

Research Publications Publication Date
DeGregorio, Wolff, and Rice. 2021. Evaluating hydrophones for detecting underwater-calling frogs: implications for monitoring imperiled species. Herpetological Conservation and Biology 16(3):513–524. | Download December 2021