Appearance:

Most distinct species of the genus. Most similar to Willow Warbler, but with much more contrasting plumage. Upperparts pure green. Throat and upper chest yellow, contrasting with pure white underparts. Distinct and strong yellow supercilium and black eye-stripe. Long primary projection, with primaries reaching middle of relatively short tail. Tertials with pale green fringes. Legs pale yellowish brown. Posture often horizontal with drooping wings.

Sound:

Song distinct. An accelerating series of sharp, metallic "swee-swee-swee-swee". Typically with a staccato beginning. Pitch drops as the speed increases and the syllables fuses into a continuous trill. Often described as the sound of a spinning coin coming to rest on a glass table. Some phrases may be given in an almost even tempo, and may recall Bonelli's Warbler. Alternative (piping) song a series of 4-6 piping, plaintive and descending "pew - pew" calls. Resembles Willow Tit's song, but is softer with each note more evenly pitched. Contact call similar to individual syllables of piping song, but with heavier accent on the ending.

Song (two variants):

Distribution:

Wikipedia: map (se also Xeno-canto below)

Ecology:

Birdlife ecology

Links:

Observation.org Latest observations

Video IBC

Image search Flickr NB! May give other species

Sound search at Xeno-canto

Featherbase

CC

Appearance:

Dark, 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

Video IBC

Image search Flickr NB! May give other species

Sound search at Xeno-canto

Featherbase

CC

Sounds:Recorded by Fernand Deroussen,http://www.xeno-canto.org ,CC license