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 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.