Sandwich Tern (Thalasseus sandvicensis)
Great Shearwater (Ardenna gravis)
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
CCLarge shearwater with distinct, marked, dark cap and white collar. Blotched belly and underwings. White upper tail-coverts forms a horseshoe mark, but note that Cory's Shearwater may show the same. Dark patch at side of neck. Bill dark. Flight action powerful, with alternating glides and rapid bursts of beats with stiff wings. Seldom soars.
Sound:Calls at breeding ground a deep, soft, moaning "oooh-aahh" ("surprised or shocked old lady"). Tone fairly clear, and pitch rising and falling.
Distribution:Wikipedia: map (se also Xeno-canto below)
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CC