The Taiwan Firecrest (Regulus goodfellowi) belongs to the Goldcrest assemblage (Regulus regulus s. l.): evidence from mitochondrial DNA and the territorial song of the Regulidae

Abstract

We evaluated the phylogenetic relationships of the Taiwan Firecrest or Flamecrest, Regulus goodfellowi, on the basis of two mitochondrial markers (cytochrome b, 16S rRNA) and territorial song. Genetic samples from eighteen subspecies of all currently accepted crest and kinglet species were available for comparison. In all molecular tree reconstructions it was clearly apparent the Taiwan endemic species was the sister species of all the palearctic Goldcrests (Regulus regulus) from Bayesian inference of phylogeny, although with weak bootstrap support and conflicting position in the ML and NJ trees. Genetic distances based on cyt-b sequences between R. goodfellowi and subspecies of R. regulus ranged between 6.1 and 8.2%. Two separate divergence time estimates dated the colonization of Taiwan to the mid to late Pliocene from 5-2 Mya. The high-pitched territorial songs of R. goodfellowi strongly resemble those of Sino-Himalayan Goldcrests (ssp. himalayensis, sikkimensis, and yunnanensis), but the terminal flourish typical of Goldcrests is invariable and only rarely included in songs of R. goodfellowi. Discriminant analysis of spectral and temporal characteristics separated the songs of the Southeast Asian populations from those of two other large clusters, the Canarian and Northwest Palearctic. Songs of R. goodfellowi were 100% correctly assigned and well distinguishable from Sino-Himalayan songs. Cluster analysis of Regulus songs strongly corroborated the sister group relationship of R. goodfellowi and R. regulus as reconstructed from concatenated mitochondrial sequence data. All results from molecular and acoustic analysis justify the species rank of the Taiwan endemic species and suggest that it is only distantly related to the firecrest clade (R. ignicapillus, R. madeirensis).

Geographical and temporal origins of terrestrial vertebrates endemic to Taiwan

“…This finding is reasonable because the close geographical setting between South China and Taiwan provides more opportunities for biotic interchange, thus lowering the genetic endemism of the Taiwanese populations (Qu et al., ). In addition, in agreement with previous studies, we recognized Indochina (Chen, Chang, et al., ; Jiang et al., ; Lv et al., ), Japan (Li et al., ; Nishizawa et al., ) and the Palaearctic (Päckert et al., ) as source regions of endemic Taiwanese species (Figure ). Nevertheless, our result revealed that three endemic species ( Myophonus insularis , Megalaima nuchalis , and Arielulus torquatus ) originated from India & Sri Lanka and the Malay Archipelago, which were rarely considered possible source regions (Figure ).…”

“…Under these scenarios, Taiwan served as a refuge for temperate species contracted from North China during the Quaternary glaciations (Chou et al., ), as indicated by the extant species (e.g. Regulus goodfellowi , Päckert et al., ), as well as the extinct species (e.g. Mammuthus trogontherii and Equus spp., Kawamura, Chang, & Kawamura, ).…”

“…2.6 Ma) when the land bridge was not present (e.g. Päckert et al., ; Shinohara et al., ); more unexpectedly, some cases even occurred prior to c . 5 Ma (e.g.…”

“…Accordingly, like newly formed oceanic islands, the present-day biota of Taiwan is expected to have originated from the Asian continent or surrounding islands (Ali, 2017). Taiwan provides varied habitats for species from diverse biomes (Chou, Thomas, Ge, LePage, & Wang, 2011) as it is geographically located at the interface of the Palaearctic and Oriental faunal zones (Päckert, Martens, & Severinghaus, 2009) and exhibits large elevational heterogeneity (Figure 1b; Ito et al, 2017). Furthermore, the periodic emergence of a land bridge that connected Taiwan to the Asian mainland during Quaternary glacial cycling contributed to intermittent biotic interchanges or geographical isolations (Qu et al, 2015).…”

Evolutionary history of passerine birds (Aves: Passeriformes) from the Qinghai–Tibetan plateau: from a pre-Quarternary perspective to an integrative biodiversity assessment

“…4 Evolutionary history of Asian Wren-Babblers (Pnoepygidae; modified from Päckert et al (2013), phylogeny based on 3457 bp concatenated cytb, ND2, GAPDH, TGFB and ODC); genetic distances (cytochrome b) indicated between clades; two species pairs occur in elevational parapatry along the southern QTP margin (Himalayas, Indo-Burmese mountains, SW China), the Sino-Himalayan high-elevation species (Pnoepyga albiventer) shows intraspecific differentiation among three separate clades and indicates species status; genetic differentiation is strongly backed by differences in song (sonagrams at the right) lineages have undergone effective shifts in morphological or behavioural traits-that are biologically meaningful in the sense of species recognition and/or reproductive barriers-can be put to test in a multidisciplinary approach including morphological, ecological and behavioural analyses, recently termed ''integrative taxonomy'' (Padial et al 2010;Schlick-Steiner et al 2010). In case of behavioural traits, passerine species having a rather stereotyped territorial song with low intra-and interindividual variation provide optimal model groups, particularly species-poor genera such as kinglets and treecreepers (Päckert et al 2003(Päckert et al , 2009Tietze et al 2008). Two examples from our own team might illustrate this approach.…”