Appearance:

Summer: Red throat (seemingly black at a distance!). Lacks white vertical framing of throat patch and white spotted back of Black-throated Diver. Winter: Quite pale. White face and eye-ring. Just a narrow stripe of dark grey along the back of the neck. In all plumages best identified by posture and silhouette, especially when seen at a distance. Slender neck, head and bill. Flat chest. Usually shows no white flank patch. Bill usually held uptilted.

Sound:

In flight; nasal, dry, gooselike series of rhythmic cackling "ko-ko-ko". Most vocal when courting and breeding. A meowing drawn-out sound starting with a register break, then falling in pitch. Display call a far reaching rolling cyclic cooing, given in long sequences.

Song/display:

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:Lauri Hallikainen, 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.