Rook (Corvus frugilegus)
Arctic Tern (Sterna paradisaea)
An all shiny black crow with diagnostic bare, pale grey base of bill, and "baggy trousers". Juveniles lacks bare bill base and are difficult to separate from Carrion Crow. Young Rooks however, has a steeper forehead and more conical bill with less curved culmen. Tail is more rounded and base of wings more narrow. Flight action includes less gliding than Carrion Crow, and individuals are more spread when a flock flies.
Sound:Makes similar caws as Carrion Crow, but is harsher, softer, flatter with less rolling r's. Also gives a varied song of soft gurgling and rattling sounds, interwoven with calls at breeding ground.
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
CCDiffers 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
Image search Flickr NB! May give other species
CC