Genetic divergence of Troglodytes troglodytes islandicus from other subspecies of Eurasian wren in northwestern Europe

Abstract

The Icelandic subspecies of Eurasian wren Troglodytes troglodytes islandicus has been described as a large wren which is sedentary on the island. It is one member of a large passerine complex which is widely distributed over the Holarctic except the Arctic. The taxonomic affiliation of the subspecies is mainly based on variation in plumage and on the song complexity. This study investigated the genetic differentiation of T. t. islandicus among the Eurasian wren subspecies in northwestern Europe, and especially in relation to its geographically proximate populations in the Faroe Islands, Scotland, southern Norway, Sweden and Denmark. Troglodytes t. islandicus and the Faroese subspecies (T. t. borealis) were genetically differentiated from the other subspecies (T. t. indigenus and T. t. troglodytes) with an estimated time of divergence from this group during the last glacial maximum; 21 thousand years before present (KYBP) [44–8]. A clear but a more recent split was observed between T. t. islandicus and T. t. borealis 12 KYBP [28–4].

Genetic Structure of the Common Eider in the Western Aleutian Islands Prior to Fox Eradication

“…Both Rock Ptarmigan and Song Sparrows show a pattern of lower genetic diversity in island populations that are distant from mainland locations Winker 2005a, Pruett et al 2010), a pattern also found in Eurasian Wrens in the north Atlantic (Amouret et al 2016). Eurasian Wrens in Iceland have lower diversity and are farther from possible source populations than those found on the Faroe Islands of Scotland.…”

The influence of wing morphology upon the dispersal, geographical distributions and diversification of the Corvides (Aves; Passeriformes)

“…For example, weak fliers may on rare occasions disperse to distant islands (e.g. [61]), and island colonization could also occur in the absence of active flight, being aided by favourable tail winds.…”

Phylogeny of the Eurasian Wren Nannus troglodytes (Aves: Passeriformes: Troglodytidae) reveals deep and complex diversification patterns of Ibero-Maghrebian and Cyrenaican populations

“…In a terminal late Pleistocene colonization event, founder populations from the European continent spread to the North Atlantic islands [49,50]. According to our SDM analyses suitable glacial refugia in south-western Europe could have harboured founder populations that colonized the British Islands via land bridges during the LGM (Fig 6B-6D).…”

“…islandicus, borealis, zetlandicus, fridariensis, hirtensis, hebridensis) found only small genetic divergence of these subspecies from populations of ssp. indigenus from Great Britain and Ireland and from continental European nominate troglodytes, suggesting recent differentiation [49,50]. All North Atlantic island subspecies thus originated from Palearctic rather than from Nearctic founders and did not substantially diverge since the colonization event [49].…”

“…Although previous studies [35,49,50] shed light on the intraspecific differentiation of the Eurasian Wren, a broader geographic and taxonomic coverage is much required. Also the phylogenetic relationships of N. troglodytes taxa distributed in the IMR within the Mediterranean Biodiversity Hotspot remain unknown.…”