Behavioral Ecology Advance Access originally published online on August 14, 2007
Behavioral Ecology 2007 18(6):1001-1009; doi:10.1093/beheco/arm069
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A comparative study of the function of heterospecific vocal mimicry in European passerines
a Department of Biology, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, B-2610 Antwerp, Belgium b Department of Functional and Evolutionary Ecology, Estación Experimental de Zonas Áridas (CSIC), Almería, Spain c Laboratoire de Parasitologie Evolutive, Université Pierre et Marie Curie, Paris, France
Address correspondence to L.Z. Garamszegi. E-mail: laszlo.garamszegi{at}ua.ac.be.
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Abstract |
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Although heterospecific vocal imitation is well documented in passerines, the evolutionary correlates of this phenomenon are poorly known. Here, we studied interspecific variation in vocal mimicry in a comparative study of 241 European songbirds. We tested whether vocal mimicry is a mode of repertoire acquisition or whether it resulted from imperfect song learning. We also investigated the effect of the degree of contact with the vocal environment (with species having larger ranges, abundance, or being long lived having a higher degree of mimicry) and a possible link with cognitive capacity (an overall larger brain in species with mimicry). Finally, we determined the potential evolutionary role of vocal mimicry in different interspecific contexts, predicting that mimicry may affect the intensity of brood parasitism, predation, or degree of hybridization. While controlling for research effort and phylogenetic relationships among taxa, we found that effect sizes for intersong interval, brain size, breeding dispersal, abundance, age-dependent expression of repertoires, and predation risk reached a level that may indicate evolutionary importance. Vocal mimicry seems to be a consequence of song continuity rather than song complexity, may partially have some cognitive component but may also be dependent on the vocal environment, and may attract the attention of predators. However, estimates of sexual selection and interspecific contacts due to brood parasitism and hybridization varied independently of vocal mimicry. Therefore, mimicry may have no function in female choice for complex songs and may be weakly selected via interspecific associations. These findings provide little evidence for vocal mimicry having evolved to serve important functions in most birds.
Key words: bird song, comparative study, learning, repertoire size, sexual selection.
Received 22 November 2006; revised 3 July 2007; accepted 3 July 2007.