Appearance:

All black swift with small white throat patch. Very difficult to separate from Pallid swift and Plain Swift. Pallid Swift; brownish plumage tone (best seen against darker background), bigger throat-patch than swift, scale pattern on body more prominent, wing-tips slightly rounded, "saddle" darker than wings, and more contrast between darker outer primaries and inner. Plain Swift; throat patch smaller and more diffuse than swift, wings and body more slender, tail noticeably deeper forked.

Sound:

A shrilling trill "zreeeee" of about 1 -2 seconds length, gradually rising in pitch with accentuated firs half, then falling from the middle of phrase. Often continued with a dry lower pitched "trrrrrr" before calling again. Very vocal at breeding area, and often a flock will call together. Despite being quite similar to Pallid Swift, the call is probably the best field character to separate the two. Pallid puts the stress on the ending of the call, followed by a quick fall in pitch (dynamics like moaning with a quick release). Plain Swift calls similar to Common Swift, but differs in slightly fluctuating pitch during the call, and a loss of resonance towards the ending (thinner sounding).

Song/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

Appearance:

Large gull with deep chest, light grey back and heavy yellow bill with red spot (adult). Pinkish legs and black tipped primaries with white windows. Winter plumage with streaked head and neck. Develops grey mantle in 2.nd winter. Young birds may be difficult to distinguish from juvenile Greater- or Lesser Black-backed Gulls, and the species shows notable variation in both plumage and size. Juveniles generally shows darker head and less contrasting markings than Greater Black-back, and pale inner primaries (window), as opposed to the all black hand of young Lesser Black-backs.

Sound:

Quite vocal. A long and strong "ay-kay-kay-kay-kay" with fading strength commonly heard. A deep "ga-ga-ga" heard from anxious birds. All calls much deeper pitched than Common Gull. Difficult to distinguish from Lesser Black-backed Gull, but tone is less nasal.

Contact call and 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

CC-sound:Jens Kirkeby, Licence,Link.