Appearance:

Olive green upperparts, yellowish chest with gradual transition to off-white belly. Very similar to Willow Warbler, and most field characters are subtle and often hard to see. Distinguished by (usually) black, or dark-brown legs, only faint dark framing to ear-coverts, less marked supercilium. Shorter primary projection (1/2 to 2/3'rds the lenght of tertials), with regularly spaced tips (visible when wing folded). Wings more fan-shaped and less pointed than in Willow Warbler. Juveniles much less yellow below than in W.Warbler. Generally leaves a duller and greyer impression than W. Warbler, but plumage very variable. Frequently flicks tail, even sideways. Generally also more active when moving among the foliage.

Sound:

Contact/alarm call a soft, plaintive ascending "hooeet". Similar to W.Warbler, but shorter with a monosyllabic feel. Song a very distinct: "chiff-chaff-chiff-chiff-chaff-chiff", in a regular clock-like rhythm. Each syllable at seemingly random pitch, but no large intervals tonally. Sometimes "get stuck" at one note.

Contact call, 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:

At a distance quite similar to Guillemot. Bill deep, rectangular and with white markings. Flanks unstreaked and armpits white. Tail longer than in Guillemot, with legs not protruding behind tail in flight. Tail often held clear of the surface when swimming. Cheeks white in winter, with broad, short and black eye stripe. Neck collar short and wide. Upperparts blacker, and underparts whiter than Guillemot. Heavy neck, head and bill, in combination with the long tail, gives it a front heavy, and different profile from Guillemot, whether perched, swimming or flying. Top of head in line with tip of uptilted bill when swimming.

Sound:

Very coarse and deep voice. Grunting or snore-like, with little phrasing. Mostly heard at breeding ground, but also sometimes at sea.

Contact 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

Sounds:Recorded by Simon Elliott,http://www.xeno-canto.org ,CC license