Iberian woodpecker to be split?

Green Woodpecker comes closer to becoming three species within the Western Palearctic. Photo: ThKraft (commons.wikimedia.org)
Green Woodpecker comes closer to becoming three species within the Western Palearctic. Photo: ThKraft (commons.wikimedia.org)

A new genetic analysis has confirmed the North African form of Green Woodpecker – Levaillant’s Woodpecker – as a full species, and brings the Iberian form closer to a split.

Two mitochondrial and five nuclear genes were used to establish that all three forms of Green Woodpecker Picus viridis did indeed share a common ancestor. Levaillant's P vaillanti split from the Iberian/European lineage between 1.6 to 2.2 million years ago, and Iberian P v sharpei from European P v viridis between 0.7 and 1.2 million years ago. All three have expanded from glacial refugia during the last part of the Ice Age, located within their core ranges in modern times.

Both timescales can be sufficient for full speciation, so are there three species in the Western Palearctic? Levaillant's molecules confirm its full species status, with a lack of gene flow after its glacial isolation and distinctive plumage characteristics; this form is already split as a separate species by many authorities. Iberian is also the bearer of diagnostic plumage patterns, mostly intermediate between Levaillant's and Green, and under the phylogenetic species concept is perhaps splittable merely on that basis. However, the authors found that specimens from southern France showed genes compatible with a narrow hybrid zone. Although such a zone does not preclude species status, and exists in several other European species pairs, the authors remain conservative in retaining Iberian as a subspecies of Green until they publish further genetic work soon. They also recommend including the Iranian subspecies innominatus in any future studies, though the Russian karelini was nested well within the variation of nominate.

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Pons, J-M, Olioso, G, Cruaud and Fuch, J. 2011. Phylogeography of the Eurasian green woodpecker (Picus viridis). Journal of Biogeography 38: 311-325.