Blyth's Leaf Warbler

Blyth's leaf warbler is a fairly bright, medium-sized Phylloscopus, yellowish-green above and white below, with two wing bars, a broad yellow-suffused eyebrow and a pale stripe crossing the grey crown. Its brighter crown stripe helps distinguish it from Emei Leaf Warbler. It often flicks its wings alternately, unlike the simultaneous wing-flicking of White-tailed Leaf Warbler, though difficult individuals may still require voice (eBird; Shanghai Birding).

The species occupies subtropical and tropical moist montane forests from the Himalayas across parts of Southeast Asia to southern China. It forages actively through foliage for insects and other small invertebrates, using its fine bill to glean prey from leaves and twigs. Its plumage resembles several related regional warblers, and the complex has a history of identification and taxonomic difficulty, making a combination of structure, behaviour, voice and location preferable (Wikipedia; BTO; BirdsandMe).