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:

Yellow legs, black to dark grey back (regional variations) and black primaries with only small white spots. Generally more slender than Herring Gull and Great Black-backed, with longer and more narrow wings, and longer legs. Winter plumage with streaked head and neck. Underside of flight feathers smoky grey. Juveniles very variable, but generally darker than Herring Gulls. Young birds with completely dark inner primaries and broad terminal band to tail.

Sound:

Very similar to Herring Gull, but tone more nasal.

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

Sounds:Recorded by Peter Boesman,http://www.xeno-canto.org ,CC license