Appearance:

Summer: Black throat framed in fine white stripes at the sides, and a chequered black back. Winter: More contrast between dark and white parts than in Red-Throated Diver. Marked transition between dark neck and white front, and the dark grey crown extends below the eye. In all plumages: Heavier neck and bill than Red-Throated, and bill usually held straight. Visibly protruding chest when swimming. Head shape sometimes squarish. Usually shows big white flank patch.

Sound:

Song: a strong, very resonant, full bodied, low whistling with most syllables rising in pitch: "co clooo-eee, co clooo-eee, co clooo-eee". Also a short grunting "karr".

Song:

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 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.