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 Arctic Tern in longer head, and more orangy red, rather than deep red, bill. Tip of bill usually black. Legs longer, but tail streamers shorter than AT. Underparts of primaries with diffusely bordered dark trailing edge (sharply bordered in Arctic Tern). Upper side of primaries with dark wedge (less apparent in winter). Secondaries opaque. Crest more apparent than in Arctic Tern and underside whiter. Juveniles with buff back.

Sound:

Similar to Arctic Tern but deeper. Lacks latter's high pitched "tip-tip-tip" call, and the drawn out "kree-aaahh" call falls more distinctly in pitch.

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:Eetu Paljakka, Licence,Link.