Yellow-browed Warbler (Phylloscopus inornatus) This is one of the smaller Old World warblers, at 9.5–11 cm long and weighing 4–9 g distinctly smaller than a Chiffchaff but slightly larger than Pallas's Warbler. Like many other leaf warblers, it has overall greenish upperparts and white underparts. It also has prominent double wing bars formed by yellowish-white tips to the wing covert feathers (a long bar on the greater coverts and a short bar on the median coverts), yellow-margined tertial feathers, and long yellow supercilium. Some individuals also have a faint paler green central crown stripe though many do not show this.[1][3][6]

It is not shy, but its arboreal life style makes it difficult to observe. It is almost constantly in motion. Its song is a high pitched medley of whistles; the call is piercing, often disyllabic "tseeweest", strikingly loud for the bird's small size. The only real possibility of confusion is with the similar-looking Hume's Leaf Warbler (P. humei), which in the limited area of overlap has duller colours, a faint second wing bar and dark legs and lower mandible. Their songs and calls are clearly distinct, with Hume's having a more chirping "chwee" call. It can easily be distinguished from Pallas's Warbler as it does not have the a conspicuous yellow central crown stripe and rump patch shown that species.[1][3]