Hooded Crow (Corvus cornix)
Whiskered Tern (Chlidonias hybrida)
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
CCLargest marsh tern. Liable to confusion with Sterna terns due to black cap, in addition to other marsh terns. All marsh terns (Chlidonias) differs from Sterna by lack of tail streamers, short tail with shallow fork, shorter wings and stiffer flight. Marsh terns don't plunge-dive for food but picks from surface (though Whiskered Tern may belly-plunge), mostly in fresh water. Adult Whiskered Tern easily told from other marsh terns by distinct black cap contrasting to white cheeks and throat. Underwing pale with diffuse dark trailing edge. Belly distinctly darker than Common- and Arctic Tern, but beware of variation in both species. Bill dark blood red. Adult winter: Very pale with no distinct markings except for ill-defined black mask stretching from eye to eye across nape. Forehead white and with crown white speckles. Bill black. Immature: Yellowish brown saddle with coarse dark pattern, though these are moulted in early autumn. Usually lacks dark carpal bar and cap ill-defined. Whiskered Tern generally stockier built than other marsh terns. Both immatures and adult winter show grey rump (different from Common, Arctic and White-Winged), and bill is dagger-shaped (most apparent in males).
Sound:Contact call freely used and fairly distinct: An extremely hoarse, and rasping "krreek" in various moods. Timbre comparable to Corncrake. Sometimes uttered in stuttering series "kr-kr-kr-kr-kr".
Contact call:
Distribution:
Xeno-canto: map
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCCC-sound:Patrik Åberg, Licence,Link.
CC-photo:Jurrien van Deijk, Licence,Link.
CC-photo:Geert Moris, Licence,Link.