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:

Large tern with black bill, with yellow tip (adults). Bill all black in juveniles. Long black cap and shaggy crest. Generally leaves a much whiter impression than other terns in the region (except Roseate Tern). Adult summer: Yellow bill-tip. Tail pure white, and upperparts pale grey. Outer primaries darker than rest of wing, and contrast increases in worn plumage. Broad white trailing edge to inner wing. Underside of primaries with faint narrow dark trailing edge. Forehead white in adult winter and first winter plumage. Juveniles: scaly upperparts and dark bill. Less evenly coloured than juvenile Gull-billed Tern. First winter birds similar to juveniles, but back purer grey and bill shorter. Can be mistaken for Gull-billed Tern, but note different profile. Flight powerful with evenly narrow wings and a front-heavy appearance, due to the long head and bill. Often dives from high above the surface and stays under water longer than Common and Arctic T.

Sound:

Contact call a sharp and grating "keeree-eek". Often compared to the pressing of amalgam into a tooth.

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:Paul:Ritchie, Licence,Link.

CC-sound:Peter Boesman, Licence,Link.