Yellow-browed Warbler

Taxobox
name = Yellow-browed Warbler
status = LC | status_system = IUCN3.1


image_width = 240px
regnum = Animalia
phylum = Chordata
classis = Aves
ordo = Passeriformes
familia = Phylloscopidae
genus = "Phylloscopus"
species = "P. inornatus"
binomial = "Phylloscopus inornatus"
binomial_authority = (Blyth, 1842)

The Yellow-browed Warbler or Inornate Warbler, ("Phylloscopus inornatus") is a leaf warbler which breeds in Asia east from the Urals to China. This warbler is strongly migratory and winters in southeast Asia.

This is an abundant bird of lowland and mountain woodlands. The nest is built in a tree. Like most Old World warblers, this small passerine is insectivorous.

There were formerly considered to be three subspecies, but "humei" and "mandellii" are now split as a separate species, the Hume's Leaf Warbler (Sangster "et al.", 2002) based on differences in morphology (Shirihai & Madge, 1993), bioacoustics (Alström & Olsson, 1988; Irwin "et al.", 2001), and molecular characters (Irwin "et al.", 2001). The Western Hume's Leaf Warbler's range overlaps with that of the Yellow-browed Warbler in the western Sayan Mountains (Ernst, 1996), but the species apparently do not hybridize (Irwin "et al.", 2001); the two species diverged roughly 2,5 mya ago (Irwin "et al.", 2001).

This tiny warbler is prone to vagrancy as far as western Europe in late September and October, despite a 3000 km distance from its breeding grounds. For example, this species occurs in late autumn in Great Britain regularly enough that it is not classified as rare there.

This is one of the smallest warblers, 9.5-10 cm long, and shares greenish upperparts and off-white underparts with typical leaf warblers. However, it has prominent double wing bars and long supercilia. The only real possibility of confusion is with Hume's Leaf Warbler, which has duller colours, a faint second wing bar and dark legs and lower mandible, in the limited area of overlap; their vocalizations are clearly distinct.

This bird is not shy, but its arboreal life style makes it difficult to observe. It is constantly in motion. Its song is weak and high pitched; the call is faintly disyllabic.

References

* Alström, Per & Olsson, U. (1988): Taxonomy of Yellow-browed Warblers. "British Birds" 81: 656–657.

* Database entry includes justification for why this species is of least concern

* Ernst, S. (1996) Zweiter Beitrag zur Vogelwelt des Östlichen Altai. "Mitteilungen aus dem Zoologischen Museum Berlin" 72, "Suppl. Ann. Ornithol." 20: 123–180. [Article in German]

* Irwin, D. E.; Alström, Per; Olsson, U. & Benowitz-Fredericks, Z. M. (2001): Cryptic species in the genus "Phylloscopus" (Old World leaf warblers). "Ibis" 143(2): 233–247. [http://www.zoology.ubc.ca/~irwin/PDFs/Irwinetal2001%20Ibis.pdf PDF fulltext]

* Sangster, George; Knox, Alan G.; Helbig, Andreas J. & Parkin, David T. (2002): Taxonomic recommendations for European birds. "Ibis" 144(1): 153–159. DOI|10.1046/j.0019-1019.2001.00026.x [http://www.blackwell-synergy.com/doi/pdf/10.1046/j.0019-1019.2001.00026.x PDF fulltext]

* Shirihai, H. & Madge, S. (1993): Identification of Hume's Yellow-browed Warbler. "Birding World" 6: 439–443.

External Links

* [http://www.bsc-eoc.org/avibase/species.jsp?lang=EN&id=5BFCC58D7572C8E9&ts=1222523356703&sec=summary Avibase] Links in turn to Flickr Handguide