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The Auk


The American Ornithologists’ Union





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The Hairy Woodpecker (Picoides villosus) has one of the broadest breeding distributions of any North American bird and is also one of the most morphologically variable with as many as 21 described subspecies. This wide distribution and high degree of phenotypic diversity suggests the presence of underlying genetic structure. We used ND2 sequence from 296 individuals from 89 localities throughout the Hairy Woodpecker distribution to address this question and to explore this species’ evolutionary history. Phylogenetic analyses identified three main Hairy Woodpecker clades, each ~1.5% divergent from one another. One clade was comprised of birds from boreal and eastern zones of North America (N&E); the second, of birds from western and southwestern North America (S&W), and the third included only birds from a disjunct population in Costa Rica and Panama. Population genetic analyses and climatic niche models indicated that the N&E and S&W clades have very different recent evolutionary histories. Populations in the N&E are characterized by a lack of genetic structure and a genetic signature of recent population expansion. In contrast, S&W populations are highly structured and relative population stability was inferred. The S&W clade is further structured into three additional geographically and genetically isolated groups: Pacific Coast ranges, interior ranges, and southern Mexico. The continental scale patterns of genetic variation observed suggest that the complex topography of the montane west has probably been more important than latitude in generating phylogenetic diversity within this species.


Biology--classification; Hairy woodpecker; phylogeography; Picoides villosus; population genetics


Ecology and Evolutionary Biology | Ornithology | Population Biology




Published in The Auk 128(2):346-362. © 2011 by the Regents of the University of California/American Ornithologists’ Union. Copying and permissions notice: Authorization to copy this content beyond fair use (as specified in Sections 107 and 108 of the U. S. Copyright Law) for internal or personal use, or the internal or personal use of specific clients, is granted by [the Regents of the University of California/on behalf of the Sponsoring Society] for libraries and other users, provided that they are registered with and pay the specified fee via Rightslink® on [JSTOR (] or directly with the Copyright Clearance Center,



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