Appearance:

Unmistakable if seen well. Corvoid-like at a distance, and may be mistaken for Jay if no plumage characters are visible. Tail is however quite a bit shorter, and wings slightly longer. Flight-feathers dark, contrasting with turquois coverts, both below and above. Underparts especially striking in flight, being pale blue (sometimes seemingly white) all over, except dark flight-feathers and base of tail. Bill heavy. Immature duller than adults with faint streaked breast and slightly rufous coverts. Wing-beats deep and regular. Flies mostly in a straight line. Migrating birds move in characteristic procession-like formations.

Sound:

Various dry rasping, sometimes mewing, sounds and short clicks: "ahrahrahrahrahrahrahr" or pulse of clicks: "trrrtrrrrtrr". Also a clearer raptor- or jay-like descending "piiuu".

Display 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:Jarek Matusiak, Licence,Link.

Appearance:

Differs from Arctic Tern in longer head, and more orangy red, rather than deep red, bill. Tip of bill usually black. Legs longer, but tail streamers shorter than AT. Underparts of primaries with diffusely bordered dark trailing edge (sharply bordered in Arctic Tern). Upper side of primaries with dark wedge (less apparent in winter). Secondaries opaque. Crest more apparent than in Arctic Tern and underside whiter. Juveniles with buff back.

Sound:

Similar to Arctic Tern but deeper. Lacks latter's high pitched "tip-tip-tip" call, and the drawn out "kree-aaahh" call falls more distinctly in pitch.

Call:

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:Eetu Paljakka, Licence,Link.