Hooded Crow (Corvus cornix)
White-winged Tern (Chlidonias leucopterus)
Unmistakable, if not in silhouette. In poor light or at a distance, when the grey plumage is not visible, confusion with other crows is possible. Bill is deeper than in Rook, and the upper mandible more curved towards the tip. Smaller than raven, and much less heavy bill. The wings are shorter and more rounded, and the tail is not wedge-shaped. Posture less upright than Rook.
Sound:Cawing is aggressive and more raucous than in Rook, with more rolling r's. Has a large repertoire of seldom heard calls, and even sub-song. Many of these calls are surprisingly resonant and pleasant sounding, and sometimes resembles Raven. Probably impossible to tell from Carrion Crow with certainty by sound alone.
Cawing:
Distribution:
Wikipedia: map (se also Xeno-canto below)
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCBreeding 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.