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:

Slender and elegant harrier, with narrow wings and four "fingers". Adult male easily recognized by very pale grey and white plumage, with diagnostic wedge-shaped, black wing-tips (outermost primary grey). Female and immature birds often difficult to tell from Montagu's Harrier and Hen Harrier. Adult female differs from Montagu's by lack of dark band on upper wing, and by diffuse, sooty inner underwing. Pale bands do not reach wingpit, and under coverts are darker. Differs from female Hen Harrier by noticeably slimmer wings (both hand and arm) and only 4 fingers (but beware moulting Hen Harriers). Immature similar to Montagu's with unstreaked, rufous underparts. Differs in pale tips of inner primaries, and dark half-collar and pale "boa".

Sound:

Some calls similar to Montagu's and Hen Harrier, but display call quite diagnostic. A thin, vibrating trill "peerrrrrrrr".

Display 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-sound:Thijs Fijen, Licence,Link.