Examining Frog Call Changes in Response to Anthropogenic Noises

Nolan Bielinski of the University of Illinois at Chicago is studying amphibian responses to human made noises in a wetland at Indiana Dunes National Park.

Photo by Nolan Bielinski

The sounds of frogs and toads are not only fun to hear, but they also serve an important purpose! The most common calls are mating calls, but others are territorial in nature, and still others are distress calls. Nolan Bielinski of the University of Illinois at Chicago wondered how anthropogenic or human-caused sounds influenced frog chorusing behavior. He is particularly looking at the impact on the chorusing behavior of spring peepers, American toads, wood frogs, and Cope’s gray treefrog.

Nolan has been conducting noise playback experiments in Indiana Dunes National Park and the Chicagoland area that manipulate the noise level at breeding ponds. On nights during his target species’ peak calling time, without rain, and with wind speeds of less than 10 mph, he plays a variety of sound scenarios, or treatments. The treatments include recordings of sounds made by cars, planes, and trains at various decibel levels.

Bielinski’s experiments will help answer several research questions. First, do frogs adjust their calls according to the type of noise broadcasted? Second, does noise effect calling behavior differently across species with varying call structures and breeding strategies?
Lastly, is there a threshold for how loud a noise has to be to affect frog calling behavior?

What will Nolan learn from his research? Stay tuned. His field work has been completed. He is currently analyzing his data and will use it to complete his PhD in 2020.