Taxonomy of the White-browed Shortwing (Brachypteryx montana) complex on mainland Asia and Taiwan: an integrative approach supports recognition of three instead of one species

Abstract

Background: The White-browed Shortwing (Brachypteryx montana) is widespread from the central Himalayas to the southeast Chinese mainland and the island of Taiwan, the Philippines and Indonesia. Multiple subspecies are recognised, and several of these have recently been suggested to be treated as separate species based on differences in morphology and songs. Methods: We here analyse plumage, morphometrics, songs, two mitochondrial and two nuclear markers, and geographical distributions of the two mainland Asian taxa B. m. cruralis and B. m. sinensis and the Taiwanese B. m. goodfellowi. Results: We conclude that these differ congruently in morphology, songs and DNA. Male B. m. goodfellowi is the most divergent in plumage (sexually monomorphic, unlike the two others; male similar to female), and B. m. cruralis and B. m. sinensis differ in male plumage maturation. The song of B. m. cruralis is strongly divergent from the others, whereas the songs of B. m. sinensis and B. m. goodfellowi are more similar to each other. Brachypteryx m. sinensis and B. m. goodfellowi are sisters, with an estimated divergence time 4.1 million years ago (mya; 95% highest posterior distribution [HPD] 2.8-5.5 mya), and B. m. cruralis separated from these two 5.8 mya (95% HPD 4.1-7.5 mya). We also report notable range extensions of B. m. sinensis as well as sympatry between this taxon and B. m. cruralis in Sichuan Province, China. Brachypteryx m. montana from Java is found to be more closely related to Lesser Shortwing (B. leucophris) and Rusty-bellied Shortwing (B. hyperythra) than to the mainland Asian and Taiwanese taxa. Conclusion: Our data support a recent proposal to treat the three mainland Asian and Taiwanese taxa as three species, separate from B. montana sensu stricto: B. cruralis (central Himalayas to south central China and south Vietnam), B. sinensis (north central to southeastern part of mainland China) and B. goodfellowi (Taiwan Island).

Species limits in the Elegant Pitta (Pitta elegans) complex from Wallacea based on bioacoustic and morphometric analysis

“…Bioacoustics continues to be a robust technique that is used in taxonomic assesments across many avian lineages-passerines and non-passerines alike (e.g., Rheindt and Eaton 2010;Rasmussen et al 2012;Collar et al 2015;Gwee et al 2019;Miller et al 2020;Rheindt et al 2020). A high level of congruence has been demonstrated for species delimitations based on bioacoustics and those based on genetic inquiries (e.g., Rheindt et al 2008;Dong et al 2015;Robin et al 2017;Alström et al 2018). Future genetic studies will be a welcome additional line of inquiry to confirm the patterns of Elegant Pitta differentiation here revealed.…”

Integrative Taxonomy Reveals Cryptic Robin Lineage in the Greater Sunda Islands

“…The same rationale can be applied to bioacoustic differences, which are arguably more important in reproductive isolation in these songbirds (Kroodsma & Miller, 1982;Kroodsma & Byers, 1991;Catchpole & Slater, 2003). The White-browed Shortwings of the Brachypteryx montana complex from mainland Asia have extensive similarities in plumage and have consequently been considered members of only one species until a combination of bioacoustic and molecular evidence led to their recent separation (Alström et al, 2018). In the same vein, vocal similarities arguably smaller than the ones observed between our robins have been documented among a number of Cyornis jungle-flycatchers (Gwee et al, 2019) that are known to be genetically deeply diverged (e.g.…”

“…Vocalizations are an important factor in reproductive isolation in songbirds and have been used in documenting cryptic, overlooked species-level diversity in other Asian robins, thrushes and flycatchers (superfamily Muscicapoidea), e.g. Brachypteryx shortwings (Alström et al, 2018), Sholicola sholakilis (Robin et al, 2017), Ficedula flycatchers (Dong et al, 2015), and Cyornis jungle-flycatchers (Gwee et al, 2019).…”

Lack of habitat segregation and no interspecific territoriality in three syntopic cryptic species of the golden‐spectacled warblers Phylloscopus (Seicercus) burkii complex

“…For example, two taxa of the white-browed shortwings Brachypteryx montana complex are sympatric in Sichuan province, China: B. m. sinensis and B. m. cruralis. Moreover, some males of these taxa apparently had overlapping territories, as both were attracted to the same spot by playback of their own song, but did not show any response to the other taxon's song (Alström et al 2018). But it seems that sympatric sibling species are separated by altitude (i.e.…”