A multilocus study of pine grosbeak phylogeography supports the pattern of greater intercontinental divergence in Holarctic boreal forest birds than in birds inhabiting other high‐latitude habitats

Abstract

Aim Boreal forest bird species appear to be divided into lineages endemic to each northern continent, in contrast to Holarctic species living in open habitats. For example, the three-toed woodpecker (Picoides tridactylus) and the winter wren (Troglodytes troglodytes) have divergent Nearctic and Palaearctic mitochondrial DNA clades. Furthermore, in these species, the next closest relative of the Nearctic/Palaearctic sister lineages is the Nearctic clade, suggesting that the Palaearctic may have been colonized from the Nearctic. The aim of this study is to test this pattern of intercontinental divergence and colonization in another Holarctic boreal forest resident -the pine grosbeak (Pinicola enucleator). Location The Holarctic.Methods We sequenced the mitochondrial ND2 gene and Z-specific intron 9 of the ACO1 gene for 74 pine grosbeaks collected across the Holarctic. The sequences were used to reconstruct the phylogeographical history of this species using maximum likelihood analysis. ResultsWe discovered two distinct mitochondrial and Z-specific lineages in the Nearctic and one in the Palaearctic. The two Nearctic mtDNA lineages, one in the northern boreal forest and one in south-western mountain forest, were more closely related to each other than either was to the Palaearctic clade. Two Nearctic Z-chromosome clades were sympatric in the boreal and south-western mountain forests. Unlike the topology of the mtDNA tree, the relationship among the Z-chromosome clades was the same as in the three-toed woodpecker and winter wren [Nearctic (Nearctic, Palaearctic)]. The Palaearctic Z-chromosome clade had much lower genetic diversity and a single-peak mismatch distribution with a mean < 25% of that for either Nearctic region, both of which had ragged mismatch distributions.Main conclusions Our data suggest that, similar to the other boreal forest species, the pine grosbeak has divergent lineages in each northern continent and could have colonized the Palaearctic from the Nearctic. Compared with many Holarctic birds inhabiting open habitats, boreal forest species appear to be more differentiated, possibly because the boreal forests of the Nearctic and Palaearctic have been isolated since the Pliocene (3.5 Ma).

Geographic mode of speciation in a mountain specialist Avian family endemic to the Palearctic

“…Despite abundant overlap in species distributions suggesting possible speciation in sympatry, our results for Prunellidae are consistent with other studies in identifying allopatric speciation as a primary mode of speciation in Palearctic bird lineages (Voelker 1999;Drovetski 2003;Drovetski et al 2004bDrovetski et al , 2010Voelker 2010). In comparison with those other studies, one significant difference here is the recent and rapid colonization of Palearctic regions, mostly in the late Pliocene to early Pleistocene.…”

“…For all individuals we sequenced the complete mtDNA ND2 gene (1041 bp GenBank accession numbers KC759264 -KC759315, we also used two additional accessions AF407039 and HM538386) and intron 9 of the Z chromosome specific Aconitase 1 gene (ACO1I9, 1094 bp; GenBank accession numbers KC759183 -KC759263). We used previously published polymerase chain reaction (PCR) profiles and primers for both ND2 and ACO1I9 (Drovetski et al 2004a(Drovetski et al , 2010. We could not amplify both loci in their entire length for fagani (n = 2) and atrogularis from the Urals (P. a. atrogularis; n = 2) due to the poor quality of DNA extracted from toe pads of museum specimens.…”

Divergent mitochondrial lineages arose within a large, panmictic population of the Savannah sparrow (Passerculus sandwichensis)

“…Resistance to population contraction and fragmentation during the Pleistocene in Savannah sparrows is consistent with several hypotheses that link ecological and life history attributes to patterns of population genetic differentiation. First, certain habitat associations can influence patterns of genetic structure with species that occupy more open and/or ephemeral habitats exhibiting less genetic structure than forest/closed habitat species (e.g., Burney & Brumfield, ; Drovetski, Zink, Ericson, & Fadeev, ; Harvey, Aleixo, Ribas, & Brumfield, ). One hypothesis explaining this pattern is that open country taxa exhibit increased dispersal propensity to exploit ephemeral or patchy resources (e.g., Burney & Brumfield, ).…”

MULTILOCUS COALESCENCE ANALYSES SUPPORT A mtDNA-BASED PHYLOGEOGRAPHIC HISTORY FOR A WIDESPREAD PALEARCTIC PASSERINE BIRD, SITTA EUROPAEA

“…Phases of sequences containing indels were sorted manually by subtracting chromatogram peaks upstream of the indel in the reverse primer sequences from the double peaks downstream of the indel in the forward primer sequences. This was repeated in the alternative direction and allowed the two haplotypes of a heterozygous individual to be determined (Sousa‐Santos et al 2005; Dolman and Moritz 2006; Drovetski et al 2010). The lengths of indels can also be determined by this approach.…”