Appearance:

Very large tern, with deep, dagger-like, blood-red bill with dark tip. Large, black cap reaching well below the eyes. Grey upperparts and white underparts. Rather short tail. Outer primaries distinctly darker than the rest of upperwing, and outer underwing almost black. Unmistakable from the size alone, and leaves a gull-like impression, lacking the elegance of smaller terns. Immatures with paler bill and white forehead (as in adult winter), and markedly speckled back. Hovers and dives. Often rests on the surface, feeding like a gull.

Sound:

Easily recognized by its very harsh calls. Sometimes likened to the sound of a plate of steel being dragged across a concrete floor. Similar in harshness to Grey Heron, but more drawn, with an accented middle; "Kraaeeet", or with a double syllable start "ka-ha-kraaaeet". Immature birds begs with a penetrating, sharp whistle.

Contact 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

CC

CC-photo:lgooch, Licence,Link.

CC-photo:Muchaxo, Licence,Link.

CC-photo:ajmatthehiddenhouse, Licence,Link.

Appearance:

Slightly smaller than Eider. Male at close range unmistakable. At a distance the black back is diagnostic. Female similar to female Eider, but feathering on bill is not reaching nostrils, giving the bird a peculiar "smile". Head shape is less triangular with a steeper forehead, and nail of bill is black. V-shaped barring on flanks.

Sound:

Male: Calls similar to Eider but easily distinguished by the vibrating quality. A "aaaooooooh" (shorter in duration than Eider) Starting on a low note, slowly ascending and ending on a descending note with a distinct vibrato/pulse. Often in the form of three calls: "oohh, a-ohhh hahahaoohohohoh". Usually accompanied by the female "ga ga ga ga".

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

CC

Sounds:Recorded by Andrew Spencer,http://www.xeno-canto.org ,CC license