White-winged Tern (Chlidonias leucopterus)
Hen Harrier (Circus cyaneus)
Breeding adult easily identified by white tail/rump combined with jet black under wing coverts and silvery upper wing. Immature with brownish back contrasting with pale, silvery upper wings and pale rump. Broad white collar, and lacks dark breast patch of immature Black Tern. Adult winter most liable to confusion with other terns, but upperparts much paler than Black Tern. Contrasting dark outer primaries and secondaries to rest of wing. Often retains some black under coverts even in winter which is diagnostic if seen. Slightly more compact than Black Tern and often recalls Little gull in shape. Bill noticeably shorter and thinner than in Whiskered Tern.
Sound:Mostly silent away from breeding ground. Most diagnostic call a dry, rolling "krrrrrr-ta-ta" where the rolling is followed by one or two accentuated syllables, or just simply "krrrrrr". Used in excitement.
Call:
Distribution:
Xeno-canto: map
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCCC-sound:Marco Dragonetti, Licence,Link.
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/