Compact leaf warbler with two whitish wingbars (one broad and prominent), greenish-gray upperparts, an indistinct crown stripe, and conspicuous white tips to the innermost flight feathers. Bill and legs usually dark. Extremely similar to Yellow-browed Warbler, but grayer and “colder” overall, with less extensive orangish coloration on the lower bill. Also compare with Two-barred Warbler and Greenish Warbler, both of which lack a crown stripe and have more extensive orange on the bill. Breeds in alpine shrubbery in mountain ranges flanking the Tibetan Plateau. Winters mostly in the plains just south of the Himalayas, but also on wet hilltops farther south. Often heard but not seen, it is best told from other leaf warblers by its distinct “chew-wee” call. Song is a remarkable descending insect-like buzz. Prone to long-distance vagrancy.