Appearance:

Diagnostic combination of blue crown, and yellow belly makes it easily recognizable. No white tail-feathers. Sexes similar, but male slightly brighter blue. Juveniles paler than adults, with greenish crown and yellowish cheeks. One of the smallest of the tits.

Sound:

Song: Characteristic, clear, high-pitched, vibrating call. Usually introduced by a couple of accenting syllables, followed by ringing vibrating notes: "ti ti chuhuhuhuhuhuhuhuhuhu". Scolding alarm call: "tee-tee-tee-chirruwitt" similar to Great Tit.

Song:

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