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:

Largest marsh tern. Liable to confusion with Sterna terns due to black cap, in addition to other marsh terns. All marsh terns (Chlidonias) differs from Sterna by lack of tail streamers, short tail with shallow fork, shorter wings and stiffer flight. Marsh terns don't plunge-dive for food but picks from surface (though Whiskered Tern may belly-plunge), mostly in fresh water. Adult Whiskered Tern easily told from other marsh terns by distinct black cap contrasting to white cheeks and throat. Underwing pale with diffuse dark trailing edge. Belly distinctly darker than Common- and Arctic Tern, but beware of variation in both species. Bill dark blood red. Adult winter: Very pale with no distinct markings except for ill-defined black mask stretching from eye to eye across nape. Forehead white and with crown white speckles. Bill black. Immature: Yellowish brown saddle with coarse dark pattern, though these are moulted in early autumn. Usually lacks dark carpal bar and cap ill-defined. Whiskered Tern generally stockier built than other marsh terns. Both immatures and adult winter show grey rump (different from Common, Arctic and White-Winged), and bill is dagger-shaped (most apparent in males).

Sound:

Contact call freely used and fairly distinct: An extremely hoarse, and rasping "krreek" in various moods. Timbre comparable to Corncrake. Sometimes uttered in stuttering series "kr-kr-kr-kr-kr".

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

CC-sound:Patrik Åberg, Licence,Link.

CC-photo:Jurrien van Deijk, Licence,Link.

CC-photo:Geert Moris, Licence,Link.

CC-photo:Michel Kapoen, Licence,Link.

CC-photo:Ria Vogels, Licence,Link.