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:

Hard to distinguish from Guillemot, especially at a distance. Bill heavier, shorter, less pointed and with lateral white stripe at base (not obvious at a distance). Flanks lacks Guillemot's streaking, and armpits are white. Upperparts blacker, without brownish tones. Tail shorter than razorbill, with protruding feet in flight. Only lower cheeks white in winter, with the area behind the eye being black (white in both Guillemot and Razorbill). Pointed (not rounded) white wedge protruding from front of chest to lower throat. Neck, head and bill, heavier than in Guillemot, but more slender than Razorbill. Bill often tilted downwards in flight.

Sound:

Coarse and deep voice, like a cross between Guillemot and Razorbill. Coarser than Guillemot but with the same laughing ending, but slower.

Contact 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

CC

CC-sounds:,www.xeno-canto.org,Andrew Spencer,http://creativecommons.org/licenses/by-nc-sa/3.0/