Appearance:

Olive green upperparts, yellowish chest with gradual transition to off-white belly. Very similar to Chiff-chaff, and most field characters are subtle and often hard to see. Distinguished by (usually) pale, yellow-brown legs, dark framing to ear-coverts, stronger supercilium. Long primary projection (often 3/4ths the length of tertials) with irregularly spaced tips (visible when wing folded). Wings slightly more pointed than in Chiff-chaff, and not so fan-shaped. Juveniles often with whole underparts yellow. Frequently flicks tail, but not sideways (unlike Chiff-chaff). Generally also more calm when moving among the foliage.

Sound:

By far most easily identified by it's call or song. Contact/alarm call a soft, plaintive ascending "hoo-eet". Similar to Chiff-chaff, but first part more drawn, giving it a disyllabic feel. Song: A 3-5 second, falling phrase of soft, rippling "svi-svi" sounds, starting high with some attack, and then falling in a mellow manner. The phrase lacks any conclusion, and diminishes both in strength and tempo.

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:

All white wingtips like Iceland Gull. The following characters applies to all ages: Told apart from Iceland Gull by angular head profile, proportionally shorter wings and long, heavy bill. Bill longer than half the length of head, and shows prominent hook. Primaries extends just about past tail in sitting birds, and the whole rear of the bird seem heavier. Eye smaller than in Iceland Gull, with a stern expression. Comparison with nearby Herring Gulls fruitful. Iceland Gull often smaller than Herring Gull, and less heavy, while Glaucous Gull usually larger. Impression reinforced by Iceland's agile maneuvering.

Sound:

Like Herring Gull.

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:Jarmo Pirhonen, Licence,Link.