Phylloscopus borealis
Like a large Willow Warbler, with distinct dark eye-stripe. Supercilium marked, but narrow. Starts at base of bill, continuing far behind eye. Wing-bar distinct on greater coverts, and sometimes on median coverts too. Primary projection long. Bill long and relatively heavy with orange base. Flanks often slightly grey, and throat sometimes with faint streaking. Appearance robust, but elegant. Moves faster and with more confidence than congeners.
Call and song diagnostic. Song a rattling series of 20-30 single syllables. Repeated as a monotonous phrase in stable pitch, lasting 2-4 seconds. Starts more softly with volume rising throughout each phrase. Contact call equally unique. A hard and short "tsrrt", recalling contact call of Dipper. Often given as introductory part of song.
Xeno-canto: map
Birdlife ecology
