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:

Differs from Arctic Tern in longer head, and more orangy red, rather than deep red, bill. Tip of bill usually black. Legs longer, but tail streamers shorter than AT. Underparts of primaries with diffusely bordered dark trailing edge (sharply bordered in Arctic Tern). Upper side of primaries with dark wedge (less apparent in winter). Secondaries opaque. Crest more apparent than in Arctic Tern and underside whiter. Juveniles with buff back.

Sound:

Similar to Arctic Tern but deeper. Lacks latter's high pitched "tip-tip-tip" call, and the drawn out "kree-aaahh" call falls more distinctly in pitch.

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

CC-sound:Eetu Paljakka, Licence,Link.