Gray-crowned warbler 
(Phylloscopus tephrocephalus)

The grey-crowned warbler (Phylloscopus tephrocephalus) is a species of Old World warbler in the family Phylloscopidae.
The bird is found in Bangladesh, China, India, Laos, Myanmar, Thailand and Vietnam.

Leaf warblers were formerly included in the Old World warbler family but are now considered to belong to the family Phylloscopidae, introduced in 2006.
The name Phylloscopus combines the Ancient Greek phullon meaning "leaf" and skopos meaning "seeker" (from skopeo, "to watch").
tephrocephalus
 Ancient Greek tephodes meaning "like ashes" or "ash-coloured",
 Cephalus: Ancient Greek: Κέφαλος Kephalos means "head".