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

Appearance:

White forehead with white wedge above eye in all plumages. Legs, and most of bill yellow in adult breeding plumage. Very small and longwinged tern. Only 2/3 of size of Common Tern. Head and bill proportionally longer than Chlidonias species and congeners, while tail is shorter. Back paler grey and belly whiter. First primaries form a dark front edge to wing. In winter the bill darkens, legs turn a dirty yellow and the white forehead expands. Juvenile resembles adult winter, but has yellowish bill base and scale patterned back. Flight fluttering with rapid wing-beats, which together with size, is usually sufficient to determine the species.

Sound:

Fairly distinct voice. Contact call a sharp "kitt", often combined to form undulating, rolling series. Not as sharp and penetrating as Common- and Arctic Tern.

Contact call:

Distribution:

Xeno-canto: map

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

CC-photo:Lars Buckx, Licence,Link.