Our analysis of the ND2 sequences revealed six clades within winter wrens (Troglodytes troglodytes). These clades corresponded to six geographical regions: western Nearctic, eastern Nearctic, eastern Asia, Nepal, Caucasus and Europe, and differed by 3-8.8% of sequence divergence. Differences among regions explained 96% of the sequence variation in winter wren. Differences among individuals within localities explained 3% of the sequence variation, and differences among localities within regions explained 1%. Grouping sequences into subspecies instead of localities did not change these proportions. Proliferation of the six clades coincided with Early and Middle Pleistocene glaciations. The distribution of winter wren clades can be explained by a series of five consecutive vicariant events. Western Nearctic wrens diverged from the Holarctic ancestor 1.6 Myr before the present time (MYBP). Eastern Nearctic and Palaearctic wrens diverged 1 MYBP. Eastern and western Palaearctic birds diverged 0.83 MYBP. Nepalese and east Asian wrens diverged 0.67 MYBP, and Caucasian birds diverged from European wrens 0.54 MYBP. The winter wren has a much greater degree of inter- and intracontinental differentiation than the three other Holarctic birds studied to date--dunlin (Calidris alpina), common raven (Corvus corax) and three-toed woodpecker (Picoides trydactylus)--and represents an example of cryptic speciation that has been overlooked.

Red'kin, Y. A. and Rohwer, S. 2004. Mitochondrial phylogeny of Locustella and related genera. */ J. Avian Biol. 35: 105 Á/110.We used maximum likelihood analysis of complete mitochondrial ND2 sequences (1041 bp) to clarify the taxonomy and relationships of various species and genera of grass and bush warblers. The tree revealed two clades of grass and bush warblers. One clade was comprised of all four western Palearctic Locustella and two species of Asian Bradypterus. The other clade included five eastern Palearctic Locustella (including the distinctive Sakhalin warbler Locustella amnicola ) and the marsh grassbird Megalurus pryeri . African Bradypterus and Australian little grassbird Megalurus gramineus were distantly related to their Asian congeners. Therefore, current taxonomy of these genera does not reflect their evolutionary history and needs revision. It is proposed that a phylogenetic analysis of morphology and ecological preferences would show that the current taxonomy of grass and bush warblers reflects species' habitat preferences and morphology related to locomotion and foraging in their habitats, rather than their shared ancestry. Distinct clades were found in grasshopper warbler Locustella naevia and Pallas's grasshopper warbler L. certhiola . Detailed phylogeographic studies are needed to elucidate the species status of the clades within these two species.

Red'kin, Y. A., Fadeev, I. V. and Nesterov, E. V. 2005. Mitochondrial DNA and plumage evolution in the white wagtail Motacilla alba . Á/ J. Avian Biol. 36: 322 Á/336.We analyzed sequences of two mitochondrial DNA (mtDNA) gene regions (control region and ND2) totaling 1477 base-pairs from 232 specimens of the white wagtail Motacilla alba obtained from 27 localities throughout Eurasia. Although overall haplotype diversity was relatively low (0.79) and the most common haplotype was shared by 45% of individuals, belonging to six subspecies, a high level of population differentiation was detected. The mtDNA tree revealed three clades: (1) most individuals from Krasnodar (belonging to M. a. alba subspecies), (2) all individuals from Almaty and some from Primor'e (belonging to M. a. personata , M. a. lugens and M. a. leucopsis subspecies), and (3) the remaining individuals (representing all subspecies and all localities except Almaty). We suggest that these three clades represent historically isolated populations that relatively recently came into secondary contact in Krasnodar and Primor'e. None of the six subspecies were reciprocally monophyletic in the mtDNA tree. The Krasnodar population appeared to receive immigrants from other localities, but distinctive haplotypes from this locality did not appear elsewhere, suggesting asymmetric gene flow. Signatures of recent gene flow between northern populations were detected, and there was no evidence of isolation by distance within the northern group of populations. Mismatch distributions for most localities were consistent with population expansions. We also analyzed 12 male plumage characters from 93 study skins sampled from 24 populations. Phylogenetic trees resulting from separate genetic and morphological analyses were incongruent. Plumage evolution seems to be under strong sexual or natural selection, which favors particular phenotypes in various areas irrespective of the mitochondrial background. Dispersal events at different evolutionary times could have obscured the effects of earlier isolation events. The mtDNA data does not support species status for M. a. lugens and M. a. personata , which shared haplotypes with other subspecies of M. alba . We recommend that M. lugens and M. personata are placed as junior synonyms of M. alba .

Hewitt's paradigm for effects of Pleistocene glaciations on European populations assumes their isolation in peninsular refugia during glacial maxima, followed by re-colonization of broader Europe during interstadials. This paradigm is well supported by studies of poorly dispersing taxa, but highly dispersive birds have not been included. To test this paradigm, we use the dunnock ( Prunella modularis ), a Western Palaearctic endemic whose range includes all major European refugia. MtDNA gene tree, multilocus species tree and species delimitation analyses indicate the presence of three distinct lineages: one in the Iberian refugium, one in the Caucasus refugium, and one comprising the Italian and Balkan refugia and broader Europe. Our gene flow analysis suggests isolation of both the Iberian and Caucasus lineages but extensive exchange between Italy, the Balkans and broader Europe. Demographic stability could not be rejected for any refugial population, except the very recent expansion in the Caucasus. By contrast, northern European populations may have experienced two expansion periods. Iberia and Caucasus had much smaller historical populations than other populations. Although our results support the paradigm, in general, they also suggest that in highly dispersive taxa, isolation of neighbouring refugia was incomplete, resulting in large super-refugial populations.