Arctic Warbler 
(Chích phương bắc, Phylloscopus borealis)

The Arctic warbler (Phylloscopus borealis) is a widespread leaf warbler in birch or mixed birch forest near water throughout its breeding range in Fennoscandia and the northern Palearctic.

This warbler is strongly migratory: the entire population winters in southeast Asia.

The name Phylloscopus combines the Ancient Greek phullon meaning "leaf" and skopos meaning "seeker" (from skopeo, "to watch").
borealis Latin borealis northern (boreas north).