Taxonomy of cryptic species in the Cyornis rubeculoides complex in the Indian subcontinent

Abstract

Taxa classified as subspecies may in fact be cryptic species. We assessed the taxonomic status of the Blue‐throated Flycatcher Cyornis rubeculoides complex in India, which consists of several forms with similar plumages and song. We used mitochondrial and nuclear DNA, plumage traits, and detailed song analysis to ascertain the taxonomic status of the different forms. The molecular data identified three primary clades: (1) in the west Himalayan foothills, (2) at higher elevations in the northeast hill states of Meghalaya, Nagaland and Mizoram, and (3) at lower elevations in the northeastern hills of Meghalaya and the east Himalayas of Arunachal Pradesh. The western clade represents nominate C. rubeculoides rubeculoides. The high‐elevation eastern clade was considered to be C. rubeculoides rogersi, because it included a sample from this subspecies from near the type locality in southwest Myanmar. These two sister clades had an estimated divergence time of 1.5 million years (my). The low‐elevation east clade has previously been assigned to C. rubeculoides, but we showed it is closely related to the Hainan Blue Flycatcher Cyornis hainanus, formerly thought to breed only further east, with an estimated divergence time of only ~0.8 my. This clade may represent a subspecies of C. hainanus or, given reports of widespread sympatry with C. hainanus in Thailand, a distinct species, Cyornis dialilaemus. However, more research is advocated, including molecular data, from the area of overlap. Songs were remarkably similar across all taxa. In playback experiments, C. r. rubeculoides in the west responded to all taxa. This is in agreement with recent work demonstrating that song differences and responses to songs are not always a good indicator of the progress of reproductive isolation.

Morphometric and genetic evidence for four species of gentoo penguin

“…Cryptic species, on the other hand, refers to taxa that cannot be readily identified using physical characters, but can be discerned using genetic and/or ecological evidence (Hosner et al, 2018). Cryptic and hidden diversity in birds has been uncovered across the world in recent years by using the PSC in conjunction with integrative taxonomic approaches combining genomics and morphometrics, particularly in biodiversity hotspots such as the oldworld tropics and neotropics (Hosner et al, 2018;Pulido-Santacruz et al, 2018;Singh et al, 2019;Younger et al, 2018Younger et al, , 2019. To manage conservation priorities in light of ongoing environmental change, it is vital to understand the true number of species that exist and their range limits, rather than relying on historic estimates.…”

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

“…A series of playback experiments revealed asymmetry in response frequency to heterospecific songs: N. moreaui responded less frequently to N. fuelleborni than to conspecific songs, whereas N. fuelleborni responded with an approximately equal frequency to both N. moreaui and conspecific songs (McEntee 2014). Similarly, blue-throated blue-flycatcher Cyornis rubeculides rubeculoides males actively responded to playbacks of both the songs of their own taxa and the songs of three related taxa that have more or less different songs (Singh et al 2019).…”

Avian haemosporidians (Plasmodium and Haemoproteus) status in selected bird groups (Old world Flycatchers, Warblers, Babblers, and Thrushes) of India and their phylogenetic relationships with other lineages of the world

“…The genomic DNA was extracted using DNeasy blood and tissue kit (Qiagen, Hilden, Germany) as described by Singh et al (2020), and species identification was done as described previously by Singh et al (2017). All DNA extraction steps were carried out in a sterile and dedicated laboratory to avoid any contamination.…”