Nuthatches eavesdrop on variations in heterospecific chickadee mobbing alarm calls
- *Department of Biology, University of Washington, Seattle, WA 98195; and
- ‡Division of Biological Sciences, University of Montana, Missoula, MT 59812
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Edited by Nancy Burley, University of California, Irvine, CA, and accepted by the Editorial Board January 31, 2007 (received for review June 21, 2006)
Abstract
Many animals recognize the alarm calls produced by other species, but the amount of information they glean from these eavesdropped signals is unknown. We previously showed that black-capped chickadees (Poecile atricapillus) have a sophisticated alarm call system in which they encode complex information about the size and risk of potential predators in variations of a single type of mobbing alarm call. Here we show experimentally that red-breasted nuthatches (Sitta canadensis) respond appropriately to subtle variations of these heterospecific “chick-a-dee” alarm calls, thereby evidencing that they have gained important information about potential predators in their environment. This study demonstrates a previously unsuspected level of discrimination in intertaxon eavesdropping.
Footnotes
- †To whom correspondence should be addressed. E-mail: ctemple2{at}u.washington.edu
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Author contributions: C.N.T. and E.G. designed research; C.N.T. performed research; C.N.T. analyzed data; and C.N.T. and E.G. wrote the paper.
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The authors declare no conflict of interest.
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This article is a PNAS Direct Submission. N.B. is a guest editor invited by the Editorial Board.
- Abbreviation:
- WSR,
- Wilcoxon's sign ranked test.
- © 2007 by The National Academy of Sciences of the USA
