Great Shearwater (Ardenna gravis)
Black-headed Gull (Chroicocephalus ridibundus)
Large 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
CCChocolate-brown hood in adult plumage (seemingly black at a distance), but head only with dark markings in winter and juvenile plumages. Underparts of inner primaries dark grey. First few primaries white with black tip, both on upper side of wing and under. Last character conspicuous in all plumages, but slightly less obvious in juveniles due to larger dark area of wing-tip. Slender-billed Gull and Bonaparte's Gull show similar white first primaries, but differs in long and slender head profile and white underparts of hand respectively.
Sound:Quite vocal, especially at breeding ground. Distinct, harsh calls. A rasping "kreearr", and shorter, sharp warning calls; "kek".
Contact call:
Distribution:
Xeno-canto: map
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CC