Sandwich Tern (Thalasseus sandvicensis)
Gannet (Morus bassanus)
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
Image search Flickr NB! May give other species
CCWhite with black wing tips and yellow-buff at back of head. Juveniles brown with small pale speckles, white u-shaped rump patch and pale underparts. Fully coloured only after 5 years, and patchy, intermediate plumages often seen. Unmistakable bird at close range or with favorable light, but can be confused with shearwaters at a distance and/or in strong wind. Differs from those by long tail and much longer neck and head. Alternates between powerful, even and shallow wing-beats and glides. Flight becomes more shearwater-like in strong winds.
Sound:Heard mostly at breeding ground. Even, rhythmical series of harsh "harrr, harrr, harrr,".
Social interaction:
Distribution:
Wikipedia: map (se also Xeno-canto below)
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCSounds:Recorded by Elias A. Ryberg,http://www.xeno-canto.org ,CC license