Appearance:

Unmistakable. Extremely long tail and short wings. Fluttering and undulating flight, with peculiar silhouette like a small ball with a long tail. Head of Northern Europe sub.sp. completely white. Continental and British birds with broad, dark supercilium. Juveniles head dark with white crown and throat. Always active and on the move in small groups.

Sound:

Song: Rapid, continuous, randomly composed sequence of bubbling,chirping sounds. Call: quite short, chirping, twittering "tzzirrret tzirrrret". Often starting at high pitch and rapidly falling, or just flat. Also a thin, slightly falling "zi zi ziii".

Contact call:

Distribution:

Xeno-canto: map

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