Appearance:

Very similar to Herring Gull, and not always possible to identify with certainty. Generally thicker neck, rounder head and longer wings than Herring Gull. Adults: Silvery upperparts, bright yellow legs (beware that it is not uncommon for Herring Gull to have yellow legs!), and more black and less white in wing-tips. Bill heavier than H.G. with markedly curved tip. Orbital ring red, not orange. Big, red gonys spot, often extending to upper mandible. Marked gonys angle. Primary feather P5 (counted from innermost feather in gulls) usually with broad, black band. In winter plumage head is less streaked than in H.G., and often completely white. Immatures first winter: Pale belly and head. Dark underwings with blotchy markings. Only vague pale window of inner primaries, and well defined, wedge-shaped tail-band. Dark base of bill. For a detailed account of all plumages see Gull Research.

Sound:

Voice more nasal than Herring Gull, but ID by sound difficult.

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

Appearance:

Unmistakable in breeding plumage, but otherwise easily confused with other marsh terns. Breeding plumage with black head and belly, but pale underwing and grey rump. When in immature and winter plumage it differs from Common and Arctic tern by smaller size and short, moderately forked tail, and from other marsh terns by slimmer body and wings (compared to White-winged tern), and relatively long, thin bill. Both immature and adult winter show dark front edge of wing, and characteristic dark shoulder patch at wing base. Back is dark in immature birds. Grey rump in all plumages. Flight usually different from Sterna-terns, with erratic dives for no apparent reason, and "aimless" change of direction. Note that when foraging over saltwater, flight becomes more Sterna-like.

Sound:

Moderately vocal. Flight call a more or less clear "kleck, or a disyllabic "klee-ake" with accented first syllable. Sometimes slightly rolling "klirr-eke", but never as much as in White-winged Tern. Also a slightly harsher "kreek", but not as raspy as in Whiskered Tern.

Flight call:

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:Ad Postma, Licence,Link.