Hume's Leaf Warbler

Like most leaf warblers it has greenish upperparts and off-white underparts, and with its long eyebrow, crown stripe and yellow-margined tertials it is very similar to the yellow-browed warbler, the best distinction being the more disyllabic call (Wikipedia, general species account).

The song is buzzing and high-pitched. The eastern and western Hume's leaf warblers already show noticeable differences in mtDNA and calls, but their songs do not differ, and they are reproductively isolated only by allopatry and not usually considered separate species (Wikipedia, general species account).