Appearance:

Unmistakable in breeding plumage, but otherwise easily confused with other marsh terns. Breeding plumage with black head and belly, but pale underwing and grey rump. When in immature and winter plumage it differs from Common and Arctic tern by smaller size and short, moderately forked tail, and from other marsh terns by slimmer body and wings (compared to White-winged tern), and relatively long, thin bill. Both immature and adult winter show dark front edge of wing, and characteristic dark shoulder patch at wing base. Back is dark in immature birds. Grey rump in all plumages. Flight usually different from Sterna-terns, with erratic dives for no apparent reason, and "aimless" change of direction. Note that when foraging over saltwater, flight becomes more Sterna-like.

Sound:

Moderately vocal. Flight call a more or less clear "kleck, or a disyllabic "klee-ake" with accented first syllable. Sometimes slightly rolling "klirr-eke", but never as much as in White-winged Tern. Also a slightly harsher "kreek", but not as raspy as in Whiskered Tern.

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

CC-sound:Ad Postma, Licence,Link.

Appearance:

Large gull with deep chest, light grey back and heavy yellow bill with red spot (adult). Pinkish legs and black tipped primaries with white windows. Winter plumage with streaked head and neck. Develops grey mantle in 2.nd winter. Young birds may be difficult to distinguish from juvenile Greater- or Lesser Black-backed Gulls, and the species shows notable variation in both plumage and size. Juveniles generally shows darker head and less contrasting markings than Greater Black-back, and pale inner primaries (window), as opposed to the all black hand of young Lesser Black-backs.

Sound:

Quite vocal. A long and strong "ay-kay-kay-kay-kay" with fading strength commonly heard. A deep "ga-ga-ga" heard from anxious birds. All calls much deeper pitched than Common Gull. Difficult to distinguish from Lesser Black-backed Gull, but tone is less nasal.

Contact call and song:

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:Jens Kirkeby, Licence,Link.