title: Cicadas impact bird communication in a noisy tropical rainforest.
abstract: Many animals communicate through acoustic signaling, and "acoustic space" may be viewed as a limited resource that organisms compete for. If acoustic signals overlap, the information in them is masked, so there should be selection toward strategies that reduce signal overlap. The extent to which animals are able to partition acoustic space in acoustically diverse habitats such as tropical forests is poorly known. Here, we demonstrate that a single cicada species plays a major role in the frequency and timing of acoustic communication in a neotropical wet forest bird community. Using an automated acoustic monitor, we found that cicadas vary the timing of their signals throughout the day and that the frequency range and timing of bird vocalizations closely track these signals. Birds significantly avoid temporal overlap with cicadas by reducing and often shutting down vocalizations at the onset of cicada signals that utilize the same frequency range. When birds do vocalize at the same time as cicadas, the vocalizations primarily occur at nonoverlapping frequencies with cicada signals. Our results greatly improve our understanding of the community dynamics of acoustic signaling and reveal how patterns in biotic noise shape the frequency and timing of bird vocalizations in tropical forests.
authors.affiliation: Department of Biology, University of Hawaii at Hilo , 200W. Kawili St. Hilo, HI 96720 .
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Hart
authors.affiliation: Department of Biology, University of Washington, 24 Kincaid Hall, Seattle WA 98105 , and.
authors.forename: Robert
authors.initials: R
authors.lastname: Hall
authors.affiliation: Department of Biology, University of Hawaii at Hilo , 200W. Kawili St. Hilo, HI 96720 .
authors.forename: William
authors.initials: W
authors.lastname: Ray
authors.affiliation: Department of Biology, University of Hawaii at Hilo , 200W. Kawili St. Hilo, HI 96720 .
authors.forename: Angela
authors.initials: A
authors.lastname: Beck
authors.affiliation: Union de Ornitologos, Apdo 182-4200, Naranjo de Alajuela, Costa Rica.
authors.forename: James
authors.initials: J
authors.lastname: Zook
keywords: acoustic partitioning; bird vocalizations.