Noisy Neighbors: Acoustic Interference and Vocal Interactions between Two Syntopic Species of Ranid Frogs, Rana clamitans and Rana catesbeiana

Abstract

Abstract American Bullfrogs (Rana catesbeiana) and Green Frogs (Rana clamitans) share ranges and breeding seasons, are ecologically similar, and often occupy the same breeding ponds throughout the summer. Males of both species use vocalizations to defend territories and attract females; however, Bullfrogs have longer calls and call much more frequently than Green Frogs. The calls of the two species overlap in frequency; thus, Bullfrog calls are a likely source of acoustic interference for Green Frogs that could affect their ability to attract females. Nevertheless, in natural settings where these species co-occur, Green Frogs reproduce successfully. This suggests that Green Frogs respond to the calling patterns of Bullfrogs in ways that maximize Green Frog signal-to-noise ratio. We used long-term pond environment recordings and bioacoustics analyzing software to explore the influence of Bullfrog calling patterns on the vocal activity of syntopic Green Frogs. We found both species call most actively within...