Chinese Bush Warbler Locustella tacsanowskia Scientific name definitions

13 cm; 9·8–12·4 g (1 Kennerley, P., and D. Pearson (2010). Reed and Bush Warblers. Christopher Helm, London, UK. Close ). A rather nondescript little bush warbler, variable in plumage tones, but with striking and unmistakable song. Has reasonably clear buffy white supercilium extending back over eye, becoming diffuse at rear, at front merging into whitish loral area (giving pale-faced appearance); crown, ear-coverts and upperparts, including wings and tail, olive-brown, ear-coverts finely streaked whitish, lower ear-coverts often with some brownish spotting; throat and center of belly whitish (on some, washed yellow), breast and flanks brownish buff (on some, quite grayish brown), generally unmarked but occasionally some faint brownish spotting across breast; undertail coverts brownish with very wide whitish feather edges (appear pale in the field); iris dark brown; bill wholly blackish in breeding plumage, at other times upper mandible blackish brown, lower mandible pinkish; tarsi pinkish. Differs from Spotted Bush Warbler Locustella thoracica in being a little less dumpy, with relatively longer tail, slightly longer bill and primaries, and plainer plumage (especially undertail coverts). Sexes alike. Juvenile is strongly washed with sulphur-yellow and has dark breast spotting; most head and body feathers replaced in October/November, then resembles adult except for abraded juvenile wing feathers (only partially molted).

E Russia (from Krasnoyarsk E through Transbaikalia to Khabarovsk region) and adjacent N Mongolia, and in NE, C & S parts of China (S to E Qinghai, SW Gansu, Sichuan and Guangxi); non-breeding S & SE Asia.