Appearance:

Unmistakable. Dark green (appears black at a distance) above and white below. Wings also dark above and white below, with diagnostic rounded and broad tips. Squarish head profile with striking crest. Winter and juvenile plumage with scaled back, and less contrasting breast band.

Sound:

Quite vocal, especially in flight at breeding ground. Territorial call: Dry, introductory phrases followed by drawn-out mewing sounds; "wyrrr-peeeoo-weeep". Alarm call "pee-wit".

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

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.

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

Sounds:Recorded by Peter Boesman,http://www.xeno-canto.org ,CC license