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:

Forked and fairly long tail. Clearly bigger than Storm Petrel, with more slender appearance and longer wings. Generally not as black, and shows brownish tone to plumage. The white rump patch is oval, has a weak grey center stripe, and does not reach as far down on the sides as in Storm Petrel. Light grey upper greater coverts form a wing-band. Underside of wings all dark. Flight pattern variable, with frequent changes in direction and speed. Sometimes glides like a shearwater but at other times shows surprisingly deep wing-beats. Does not patter surface, but will rest on water. Visits breeding ground only at night, and is usually only seen after storms.

Sound:

Only calls at breeding ground. A series of accentuated cooing, interrupted by a squeaky "inbreath" and a loud, absurd, fanfare-like "kaaa-ka-ka-kaaa-ka".

Calls:

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-sound:Steph, Licence,Link.