Scientific name: Phylloscopus trochiloides (Sundevall, 1837)
Bird group: Warblers
Field characters. 11 cm. Resembles Arctic Warbler. Yellowish-green or olive-green on head and upperparts. Flight feathers with green or yellowish edges. Underparts cold grey-white, sometimes with pale yellowish wash on face and sides of breast. Long and obvious supercilium, from base of bill to side of crown, but not quite as long as in Arctic Warbler. Dark eye-stripe, as in Arctic Warbler, but ear-coverts less mottled, more uniform. A single wing bar, formed by pale tips of greater coverts, sometimes inconspicuous. Legs usually dark.
Voice. Call 'che wee', like call of White Wagtail. Song loud, chattering and Northern Wren-like.
Distribution. Uncommon but increasing summer visitor in north-east Europe.
Habitat. Open woodland and edges, especially in mixed and spruce forest with dense undergrowth on slopes.
Food. Mainly insects.