Appearance:

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

Video IBC

Image search Flickr NB! May give other species

Sound search at Xeno-canto

Featherbase

CC

Appearance:

Differs from Common Tern in shorter head, and blood-red bill. Legs shorter, but tail streamers longer (extends well past wings in sitting birds). Underparts of primaries with sharply bordered dark trailing edge (diffusely bordered in Common Tern). Both primaries and secondaries transparent to sunlight. Crest less apparent than in Common Tern and underside greyer. Cheeks white just below the black cap, often in contrast to grey lower cheeks. Juveniles lacks buff coloured back.

Sound:

Similar to Common Tern but higher pitched. Typical call a series of high pitched "tip-tip-tip", and longer, ringing, high-pitched "kriiiiii" calls. The drawn out "kree-aaahh" call falls less distinctly in pitch than Common Tern.

Calls:

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:Stein Ø. Nilsen, Licence,Link.