Cory's Shearwater (Calonectris diomedea) -> Lesser Black-backed Gull (Calonectris diomedea) - BirdID's Bird Guide - Nord University

Species:

Cory's Shearwater (Calonectris diomedea)

Lesser Black-backed Gull (Larus fuscus)

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Great Shearwater

Glaucous Gull

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Fulmar

Iceland Gull

Length (cm):

45-46

52-64

Wingspan (cm):

105-125

117-134

Weight (gram):

800-1100

620-1000

Size group:

Crow-size

Bigger than a crow

Main Texts:

Appearance:

A large shearwater with pale upperparts and heavy, yellowish bill. Large grey head. The grey neck forms a diagnostic, contrasting line from wing base to base of bill (most other shearwaters have white neck-sides). Armpits usually pure white. Underside of wings white, framed by black flight feathers. Flight action calm and distinct. Long glides alternates with 3-4 slow wingbeats. Wingtips always bent downwards, and wings slightly angled back. Often soars. Differs from Fulmar in dark tail, grey head, long, narrow wings and longer bill. The two subspecies C. diomedea and C. borealis, are somtimes treated as different species. Field identification of these usually impossible, and requires ideal conditions. Hand of borealis is darker due to no white fringes to primaries. In diomedea the white in the coverts extends in a white wedge into the hand, through the base of the primaries.

Sound:

Very vocal at breeding ground. Calls with a very nasal, comical, mewing "ke-kooeee", ending with falling pitch, like a releasing sigh or moan. Sometimes reltively pure, other times very hoarse and raucous.

At breeding ground (C. d. borealis):

Error loading Flash for sound!
See sound file

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

Featherbase

CC

CC-sound:James Bradley, Licence,Link.

CC-photo:Hans Verdaat, Licence,Link.

Appearance:

Yellow legs, black to dark grey back (regional variations) and black primaries with only small white spots. Generally more slender than Herring Gull and Great Black-backed, with longer and more narrow wings, and longer legs. Winter plumage with streaked head and neck. Underside of flight feathers smoky grey. Juveniles very variable, but generally darker than Herring Gulls. Young birds with completely dark inner primaries and broad terminal band to tail.

Sound:

Very similar to Herring Gull, but tone more nasal.