Summary: | Capsule Atlantic Island Wrens are very closely related to mainland European populations. Aims The first genetic screen of the North-east Atlantic island subspecies of (Winter) Wren Troglodytes troglodytes was performed to resolve their relationship to mainland Eurasian and Nearctic populations. Methods The ND2 gene was sequenced from 15 wrens from Iceland, Faroe Islands, St Kilda, Outer Hebrides, Fair Isle and Shetland (2–3 individuals of each subspecies) and compared with Eurasian Wrens from mainland Britain and Europe, and Winter Wrens from North America. Results All island subspecies were shown to originate from European rather than Nearctic founders. Genetic divergence from mainland British and European populations was small (0.1–0.3% uncorrected). The major European haplotype was present in some individuals from Shetland, Fair Isle and Faroes. Novel unique haplotypes were found in all individuals of St Kilda, Iceland and Hebridean Wrens, and in two individuals of Fair Isle Wren, contrasting with the high inferred levels of gene flow across Europe. Conclusions Genetic data are consistent with a postglacial colonization of Atlantic islands from mainland Britain and Europe, possibly with continued gene flow due to migration of European birds. Tentatively, St Kilda Wren and Iceland Wren may be more closely related; most other subspecies are probably polyphyletic.
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