Raising a racket: invasive species compete acoustically with native treefrogs – via Herp Digest

Animal Behaviour

Volume 114, April 2016, Pages 53–61

Jennifer B. Tennessena, , ,

Susan E. Parksb, 1,

Travis P. Tennessenc, 2,

Tracy Langkildea, 3

Highlights

• Sounds produced by invasive species can limit communication space.

• Invasive treefrogs compete acoustically with native treefrogs with similar calls.

• These native treefrogs modify call behaviour but those with different calls do not.

• These findings extend the scope of effects of noise pollution to include invaders.

• Fitness-relevant consequences of acoustic competition may shape native communities.

Environmental noise is increasing worldwide, limiting the space available for species to send and receive important acoustic information. Many invasive species produce acoustic signals that alter the spectrotemporal characteristics of available signalling space. This provides an opportunity to test ideas about competitive exclusion by quantifying whether species with shared requirements for acoustic resources will become excluded or partition resource use to permit coexistence. We conducted a field playback experiment to test whether native treefrogs (green treefrogs, Hyla cinerea; pine woods treefrogs, Hyla femoralis) modify their acoustic behaviour to minimize acoustic competition from chorus noise of the invasive Cuban treefrog, Osteopilus septentrionalis. We demonstrate that noise from an invasive species differentially affects the vocal behaviour of native species. Those with similar calls (H. cinerea) shortened calls, called louder and persisted calling in response to masking stimuli while those with different calls (H. femoralis) did not modify behaviour. This evidence suggests that acoustic competition by invasive O. septentrionalis has altered the acoustic community structure, identifying acoustic competition as a mechanism by which invasive species can impact communities. Furthermore, these results broaden the concept of noise pollution, demonstrating fitness-relevant consequences of noise produced by invasive species.

Correspondence: J. B. Tennessen, Department of Biology, The Pennsylvania State University, 208 Mueller Laboratory, University Park, PA 16802, U.S.A.

1

E-mail address: sparks@syr.edu (S. E. Parks).

2

T. P. Tennessen is now at the Center for Service-Learning, Western Washington University, Wilson Library 481, Mail Stop 9125, 516 High Street, Bellingham, WA 98225-9125, U.S.A. E-mail address: travis.tennessen@gmail.com (T. P. Tennessen).

3

E-mail address: tll30@psu.edu (T. Langkilde).