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:

Differs from Common and Arctic Tern by; noticably shorter wings, longer streamers, much paler grey upperparts, pure white underparts (faint rosy wash not very conspicuous), black bill (red base in breeding birds), dark outer primaries and no dark edge to inner primaries. Amount of red in bill increases as breeding season progresses, but also varies geographically. Wingbeats shallower and much quicker than in Common and Arctic Tern. Fishes with characteristic diagonal dives. Despite the long streamers, the birds appear short-tailed in flight, but head and bill are long and slender. The pale plumage, dark bill and giss recalls a small Sandwich Tern. Adult winter plumage with all dark bill and white forehead. Juveniles resembles juvenile Sandwich Terns, with more complete dark cap than Arctic and Common, and much more contrasting markings on back (especially to wings).

Sound:

Extremely harsh calls. Like mix of Caspian and Arctic Tern. Very hard and raspy "kreeeet", harder and higher pitched than Caspian Tern, but equally harsh. Other calls include more Arctic/Common tern-like short "kek", and similar.

Contact 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

CC

CC-photo:USFWS/Southeast, Licence,Link.

CC-photo:Werner Witte, Licence,Link.

CC-photo:Anita363, Licence,Link.

CC-photo:Mike Prince, Licence,Link.