Arctic Warbler (Phylloscopus borealis)
Parasitic Jaeger (Stercorarius parasiticus)
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.
Sound: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.
Song (two variants) and calls:
Distribution:
Xeno-canto: map
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCDark, pale and intermediate morphs. Pale birds more common in northern parts of species range, darker morphs more common further south. Elongated middle tail feathers (projection comprising about half the total tail length), but not as long as in adult Long-tailed skua. White patches at base of primaries, both on upper and underside of wings. Dark morph chocolate brown with darker hood. Pale morph with white throat and belly and incomplete breast band. Relatively marked transition from pale belly to dark vent (as opposed to Long-tailed). Size close to Common Gull. Flight powerful, elegant and falcon-like. Juveniles with short but pointed middle tail-feathers. Confusion with other juvenile skuas very likely. Differs from Long-tailed in prominent white base of most primaries on upper side of wing (not just the first few feathers). Lacks the double white patch of Pomarine Skua's underwing, and shows less contrast between back and rump. Wings broader than Long-tailed but narrower than Pomarine. Approximately equal to distance from wing rear edge to tail-tip (projections excluded).
Sound:Mostly heard at breeding ground. Most characteristic call is a mewing, kittiwake-like "aeeeee-ah". First syllable drawn-out and rising in pitch, and followed by a deeper conclusive second syllable "ah". Lacks the introductory double accent of Kittiwakes ("kitti-wake").
Alarm call/flight call:
Distribution:
Wikipedia: map (se also Xeno-canto below)
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCSounds:Recorded by Fernand Deroussen,http://www.xeno-canto.org ,CC license