Long suspected to be four separate species, this taxonomic status of the Narcissus/Yellow-rumped Flycatcher complex in Asia now appears to be confirmed.
Using analysis of plumage, structure, vocalisations and three each of the mitochondrial and nuclear genes, all four taxa were shown to be differentiated enough to be regarded as full species.
The species are Narcissus Flycatcher Ficedula narcissina (which breeds in Japan and winters south to Borneo); F owstoni (resident in the most southerly Japanese islands); F elisae (sympatric with Yellow-rumped in a small area of inland eastern China); and Yellow-rumped Flycatcher F xanthopygia (mainland China, wintering in Sumatra). Vocalisations were 100 per cent distinguishable between the four taxa, and though the northern populations of F owstoni were somewhat intermediate between southern owstoni and narcissina, they were still recognisable structurally as owstoni.
No English names are proposed for the two former subspecies of F narcissina, but both are already considered by the authors to be globally threatened as they have small and fragmentary populations.
Dong, L, Wei, M, Alström, P, Huang, X, Olsson, U, Shigeta, Y, Zhang, Y, and Zheng, G. 2015. Taxonomy of the Narcissus Flycatcher Ficedula narcissina complex: an integrative approach using morphological, bioacoustic and multilocus DNA data. Ibis 157: 312-325.