Hen Harrier (Circus cyaneus)
Black Tern (Chlidonias niger)
In all plumages: Glides with wings raised in shallow V. Shows 5 primaries. This makes the wing tip broader than in Pallid- and Montague's Harriers, and the wings seems shorter. (Note that moulting individuals may show only 4 primaries). Male; grey with black primaries, white rump and underparts, and broad black trailing edge to underwing. Note that subadult males may show partly black primaries like Pallid. Female; brown with white rump, barred tail and streaked underparts.
Sound:Mostly heard at breeding ground. Calls with quite soft series of "ke-ke-ke-ke". Also a wailing, squealing whistle, with emphasized first syllable.
Contact call:
Distribution:
Wikipedia: map (se also Xeno-canto below)
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCSounds:Creative Commons,www.xeno-canto.org,Bruno Durand,http://creativecommons.org/licenses/by-nc-sa/4.0/
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
Image search Flickr NB! May give other species
CC