Song convergence in multiple urban populations of silvereyes (Zosterops lateralis)

Authors


  • Holsworth Wildlife Research Endowment (#84113) and Birds Tasmania (private grant) both to D. A. P.

Correspondence

Dominique A. Potvin, Department of Zoology, University of Melbourne, VIC 3010, Australia. Tel: +61 3 8344 6256; Fax: +61 3 8344 7909; E-mail: d.potvin@student.unimelb.edu.au

Abstract

Recent studies have revealed differences between urban and rural vocalizations of numerous bird species. These differences include frequency shifts, amplitude shifts, altered song speed, and selective meme use. If particular memes sung by urban populations are adapted to the urban soundscape, “urban-typical” calls, memes, or repertoires should be consistently used in multiple urban populations of the same species, regardless of geographic location. We tested whether songs or contact calls of silvereyes (Zosterops lateralis) might be subject to such convergent cultural evolution by comparing syllable repertoires of geographically dispersed urban and rural population pairs throughout southeastern Australia. Despite frequency and tempo differences between urban and rural calls, call repertoires were similar between habitat types. However, certain song syllables were used more frequently by birds from urban than rural populations. Partial redundancy analysis revealed that both geographic location and habitat characteristics were important predictors of syllable repertoire composition. These findings suggest convergent cultural evolution: urban populations modify both song and call syllables from their local repertoire in response to noise.

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