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

Appearance:

White forehead with white wedge above eye in all plumages. Legs, and most of bill yellow in adult breeding plumage. Very small and longwinged tern. Only 2/3 of size of Common Tern. Head and bill proportionally longer than Chlidonias species and congeners, while tail is shorter. Back paler grey and belly whiter. First primaries form a dark front edge to wing. In winter the bill darkens, legs turn a dirty yellow and the white forehead expands. Juvenile resembles adult winter, but has yellowish bill base and scale patterned back. Flight fluttering with rapid wing-beats, which together with size, is usually sufficient to determine the species.

Sound:

Fairly distinct voice. Contact call a sharp "kitt", often combined to form undulating, rolling series. Not as sharp and penetrating as Common- and Arctic Tern.

Contact call:

Distribution:

Xeno-canto: map

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-photo:Lars Buckx, Licence,Link.