Hume’s leaf warbler  – Phylloscopus humei
Hume’s leaf warbler or Hume’s warbler is a small leaf warbler which breeds in the mountains of inner Asia. This warbler is migratory and winters mainly in India.

Like most other leaf warblers, it has greenish upperparts and off-white underparts. With its long supercilium, crown stripe and yellow-margined tertial remiges, it is very similar to the yellow-browed warbler (P. inornatus). However, it has only one prominent light wing bar, just a faint vestige of the second shorter wing bar, and overall duller colours. It also has a dark lower mandible and legs.

Its song is buzzing and high pitched. The best distinction from the yellow-browed warbler is the more disyllabic call. While the eastern and western Hume’s leaf warblers already show noticeable differences in mtDNA sequence and calls, their songs do not differ; they are reproductively isolated only by allopatry and not usually considered separate species.

This bird is not shy, although its arboreal lifestyle and cryptic colours make it difficult to observe. It is constantly in motion. Like most “Old World warblers”, this small passerine is insectivorous. The nest is built on the ground.

It sounds like this
Recording by Joost van Bruggen from Xeno canto