
Photo: egorbirder · CC BY 4.0 (May be cropped or resized)
Phylloscopus trochiloides
Habitat
In Bhutan, humid Bhutan fir forest up to about 3,800m or more; elsewhere lowland deciduous or mixed forest; nest on the ground in low shrub
Range
Breeds in north-eastern Europe and temperate to subtropical continental Asia; winters in India
Size
Small
The greenish warbler is a widespread leaf warbler breeding in north-eastern Europe and temperate to subtropical continental Asia, and strongly migratory, wintering in India. It is a typical leaf warbler, greyish green above and off-white below, and the single wing bar found in southern and western populations distinguishes it from most similar species (Wikipedia, general species account).
Birds from south-east of the Himalayas are quite often seen in Bhutan during the hot months, typically in humid Bhutan fir forest up to about 3,800m or more, but they do not breed there and return to the adjacent subtropical lowlands in winter. The song is a high jerky trill, and the nest is on the ground in low shrub.