Species delimitation of the white‐tailed rubythroat Calliope pectoralis complex (Aves, Muscicapidae) using an integrative taxonomic approach

Abstract

Our knowledge of the systematics and taxonomy of Asian birds has improved much in the last two decades, and the number of recognised species has increased significantly as a result of in‐depth studies using an integrative taxonomic approach. The Sino‐Himalayan mountains harbor a high level of passerine diversity. Several allopatric or parapatric taxa that are currently treated as subspecies of polytypic species within that region are likely to deserve full species status, and thus their taxonomic status needs to be revisited. Based on analyses of multilocus data, vocalizations and morphology, we propose that the white‐tailed rubythroat Calliope pectoralis should be treated as two species, the Himalayan rubythroat C. pectoralis sensu stricto in the Tian Shan and Himalayan mountains, and the Chinese rubythroat C. tschebaiewi in the mountains of southwestern and north‐central China. According to our dating analyses based on mitochondrial loci, these two species diverged approximately 2.2 million yr ago. We further found that C. tschebaiewi was paraphyletic to C. pectoralis sensu stricto in nuclear data, which demonstrates a state of mitonuclear discordance that warrants further work. Our results suggest that geographic changes and glacial cycles in the Pleistocene may have caused allopatric divergence in the C. pectoralis complex. Our study stresses the importance of applying an integrative taxonomy approach to fully unravel the true avian diversity in the Sino‐Himalayan Mountains.

Diversification of a ‘great speciator’ in the Wallacea region: differing responses of closely related resident and migratory kingfisher species (Aves: Alcedinidae:Todiramphus)

“…This is also the case for the Collared Kingfisher species complex. While morphology and phylogenetics have co-varied in many taxa (Jablonski & Finarelli 2009, McKay et al 2010, Dong et al 2015, Liu et al 2016 there are multiple examples of differing morphological and phylogenetic patterns, particularly in recently diverged island fauna (Cibois et al 2007, Phillimore et al 2008, Saitoh et al 2012. While morphology and phylogenetics have co-varied in many taxa (Jablonski & Finarelli 2009, McKay et al 2010, Dong et al 2015, Liu et al 2016 there are multiple examples of differing morphological and phylogenetic patterns, particularly in recently diverged island fauna (Cibois et al 2007, Phillimore et al 2008, Saitoh et al 2012.…”

“…Although Andersen et al (2015b) significantly revised the taxonomy of this remarkable diversification, the morphological and ecological adaptations that led to the isolation of the different populations remain to be studied. While morphology and phylogenetics have co-varied in many taxa (Jablonski & Finarelli 2009, McKay et al 2010, Dong et al 2015, Liu et al 2016 there are multiple examples of differing morphological and phylogenetic patterns, particularly in recently diverged island fauna (Cibois et al 2007, Phillimore et al 2008, Saitoh et al 2012.…”

No evidence of genetic structure in a sky island endemic: implications for population persistence under a shrinking thermal niche

“…From a purely genetic perspective, our results suggest C. frenatus and C. aurantius have low species-level diversity based on uncorrected p -distance values. Our recorded cytbp-distance result for C. frenatus -C. aurantius (1.5 %) was below most p -distance values for species-level distances of 3.3-12.8 % in passerines (Liu et al, 2016;Luo et al, 2014;Martens, Tietze, & Sun, 2005), although (Martens, Tietze, & Päckert, 2011) suggested sister-species can be <3 %. Similarly, our recorded ND2 p -distance result for C. frenatus -C. aurantius (4.3 %) was at the lower range of p -distance values for previous species-level distances of 2.0-13.7 % of passerines (Aliabadian et al, 2012;Luo et al, 2014;Zuccon & Ericson, 2012).…”

“…These three markers were chosen as they remain relevant in studies on avian population structure (e.g. Liu et al, 2016;Dantas et al, 2019;Stervander, Ryan, Melo, & Hansson, 2019), as well as general avian taxonomy (Ericson, Klopfstein, Irestedt, Nguyen, & Nylander, 2014). We hypothesized that unsuitable lowland habitat between the geographically distinct mountain ranges would act as a barrier to effective dispersal between populations, resulting in genetic structuring aligned with the topography of the Cape Fold Belt.…”

Molecular Species Delimitation of Larks (Aves: Alaudidae), and Integrative Taxonomy of the Genus Calandrella, with the Description of a Range-Restricted African Relic Taxon

“…However, we acknowledge that the Calandrella larks are poorly differentiated morphometrically (Figure 1), and we stress that other types of data, in combination with dense taxon sampling, are necessary for confident taxonomic revisions. Here, we lack substantive data from nuclear DNA markers, vocalizations, other behaviours, ecology etc., to take the fully integrative taxonomic approach [108][109][110] that is becoming more common, e.g., [111][112][113][114][115][116][117][118][119][120] and which we argue should be the gold standard. Yet, while we emphasize that taxonomic decisions should never rest on mitochondrial trees alone [101,106], we here make use of available morphometric data and evaluate a recent tool for single-locus molecular species delimitation [54], which has been used to propose avian taxonomic revisions based solely on mitochondrial data [121] or in combination with morphometry [65].…”