Small brown warbler of middle elevations, usually retiring and seldom venturing far from the bushes and short trees from which it gives its distinctive song. Rich, dark brown above and paler gray-brown below, with tawny-brown flanks and pale supercilium. Song a resonant, long whistle followed by a short burst of sharp, bright notes, similar to songs of much larger Manchurian and Japanese Bush Warblers but the whistle is much longer and the following notes not as soft and mellow. Endemic Taiwan subspecies (robustipes) sometimes considered species, called Strong-footed Bush Warbler.