Large, elongated brown warbler with a long slender bill. Fairly similar in appearance to Chinese, Baikal, and Spotted Bush Warblers, but breeding ranges do not overlap. Like other bush warblers, typically very skulking and furtive, preferring to run instead of fly when threatened. Emerges onto small bushes to sing, producing a dull clicking that would underwhelm a grasshopper. Breeds in weedy and bushy slopes in open alpine and subalpine areas; wintering habitat poorly understood but presumed to be similar habitat at lower altitudes.