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:

Summer: Red throat (seemingly black at a distance!). Lacks white vertical framing of throat patch and white spotted back of Black-throated Diver. Winter: Quite pale. White face and eye-ring. Just a narrow stripe of dark grey along the back of the neck. In all plumages best identified by posture and silhouette, especially when seen at a distance. Slender neck, head and bill. Flat chest. Usually shows no white flank patch. Bill usually held uptilted.

Sound:

In flight; nasal, dry, gooselike series of rhythmic cackling "ko-ko-ko". Most vocal when courting and breeding. A meowing drawn-out sound starting with a register break, then falling in pitch. Display call a far reaching rolling cyclic cooing, given in long sequences.

Song/display:

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:Lauri Hallikainen, Licence,Link.