Old divergences in a boreal bird supports long-term survival through the Ice Ages

Abstract

BackgroundUnlike northern Europe and most of northern North America, the Eastern Palearctic and the northwesternmost tip of North America are believed to have been almost unglaciated during the Quarternary glacial periods. This could have facilitated long-term survival of many organisms in that area. To evaluate this, we studied the phylogeography in east Asia and Alaska of a boreal migratory passerine bird, the Arctic Warbler Phylloscopus borealis, and compared our results with published data on especially North American species.ResultsIn a sample of 113 individuals from 18 populations we identified 42 haplotypes of the mitochondrial cytochrome b gene, which separated into three clades: A - Alaska and mainland Eurasia (except Kamchatka); B - Kamchatka, Sakhalin and Hokkaido; and C - Honshu, Shikoku and Kyushu (i.e. Japan except Hokkaido). The oldest split among these clades, between A/B and C, is estimated to have taken place sometime between the mid Pliocene and early Pleistocene, and the second divergence, between clades A and B, in the early to mid Pleistocene. Within all of the three main clades, there are signs of population expansion.ConclusionsThe Arctic Warbler separated into three main clades in close succession around the Pliocene/Pleistocene border, with the two northern clades diverging last. All three clades probably experienced population bottlenecks during the Pleistocene as a result of range shifts and contractions, but nevertheless survived and maintained their integrities. Several other clades of Northeastern Palearctic birds are noted to have diversified during the Pliocene. In contrast, avian species or phylogroups presently occupying formerly glaciated North American ground are generally younger. The differences between these regions could be due to slower speciation rates in the Eastern Palearctic due to less fragmentation of forest habitats during glacial periods, or to longer survival of Eastern Palearctic clades as a result of less severe conditions in that region compared to northern North America. Several other Palearctic organisms show concordant biogeographical patterns to that of the Arctic Warbler, indicating common causes of their diversifications.

A review of the recent advances in the systematics of the avian superfamily Sylvioidea

“…No fewer than six species new to science have been described in that period: P. hainanus (Olsson et al, 1993), P. emeiensis (Alström and Olsson, 1995), S. omeiensis (Martens et al, 1999), S. soror (Alström and Olsson, 1999), P. occisinensis (Martens et al, 2008) and P. calciatilis . Moreover, taxonomic revisions have led to the recognition of several new species: P. canariensis and P. ibericus (previously treated as subspecies of P. collybita; P. ibericus formerly incorrectly called P. brehmii) (Helbig et al, 1996;Salomon et al, 1997;Helbig et al, 2001;Bensch et al, 2002;Salomon et al, 2003); P. orientalis (previously subspecies of P. bonelli; Helbig et al, 1995); P. borealoides (previously synonym of P. tenellipes ;Martens, 1988); P. chloronotus (previously subspecies of P. proregulus; Martens et al, 2004); P. forresti (previously synonym of P. proregulus chloronotus; Martens et al, 2004); P. kansuensis (previously synonym of P. p. proregulus;Alström et al, 1997;Martens et al, 2004); P. yunnanensis (previously synonym of P. proregulus chloronotus; nensis in latter study]; Martens et al, 2004); P. claudiae, P. goodsoni and P. ogilviegranti (two former previously subspecies of P. reguloides, third previously subspecies of P. davisoni; Olsson et al, 2005;Päckert et al, 2009); P. examinandus and P. xanthodryas (previously subspecies of P. borealis; Saitoh et al, 2006Saitoh et al, , 2008Saitoh et al, , 2010Reeves et al, 2008;Martens, 2010;Alström et al, 2011d); S. Family Phylloscopidae based on concatenated nuclear MB and mitochondrial cytochrome b and 12S sequence data, based on Olsson et al (2004Olsson et al ( , 2005, Alström et al (2006…”

Multilocus phylogeography (mitochondrial, autosomal and Z-chromosomal loci) and genetic consequence of long-distance male dispersal in Black-throated tits (Aegithalos concinnus)

“…However, we believe that convincing conclusions can only be obtained after a fuller understanding of the information regarding the evolutionary processes that led to these genetic differences. In East Asia, several birds have similar divergent patterns to the Black-throated tits in mtDNA (Zou et al, 2007;Saitoh et al, 2010). For example, Grey-cheeked fulvetta (Alcippe morrisonia) subspecies were diverged to the extent of 5%, and a particularly deep division (9%) separates the geographically central clade from the geographically peripheral clade (Zou et al, 2007).…”

Taxonomic recommendations for British birds: eighth report

“…Molecular studies have identified three strongly divergent groups within the Arctic Warbler complex (Saitoh et al . , see also Reeves et al . ).…”