felosa-boreal Phylloscopus borealis

Dull, relatively unmarked olive-brown warbler with a prominent yellowish-white eyestripe, faint wingbars, and pale whitish underparts. Visually inseparable from Japanese and Kamchatka Leaf Warblers; listen for song, an electric chattery trill. Also gives a metallic two-noted call and a short harsh buzz. Breeds in shrubby areas, often near water, throughout the Eurasian taiga. Breeding range extends to Alaska, where it is the only leaf warbler. Winters in lowland and foothill forest, forest edge, and gardens, primarily in Southeast Asia.