Blunt-winged Warbler Acrocephalus concinens concinens breeds patchily across much of eastern China, north to Hebei. Winters in Southeast Asia. Breeds in reeds but also in montane scrub and grasslands away from water; to 3000 m. Formerly considered conspecific with paddyfield warbler; also similar to Manchurian reed warbler. Drabber and more uniform than other small Acrocephalus warblers in eastern China, with the most weakly marked head. Lacks band on crown above whitish supercilium, which is pale and diffuse and usually does not extend beyond eye. Upperparts brownish-olive, rump more rufous (but shows less contrast than Manchurian and black-browed reed warbler). Whitish on chin and throat, sandy brown across breast, whiter on belly; flanks and vent may approach brownish-olive hue of upperparts. Unlike others in genus, the short, rounded wings do not reach base of tail, and the primary projection is extremely short. Long bill grey above, pink below. Feet grey-brown. Song a series of slurred whistles, chirrs, and buzzes, slower than black-browed reed warbler’s. Calls a short, quiet “check” and a softer, longer “chirr.” — Craig Brelsford
Daniel Bengtsson served as chief ornithological consultant for Craig Brelsford’s Photographic Field Guide to the Birds of China, from which this species description is drawn.