Swift (Apus apus)
Sooty Shearwater (Ardenna grisea)
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
Image search Flickr NB! May give other species
CCDark-bellied, long-billed shearwater with small head and elongated body. Wings long, narrow and pointed, with pale patches/bands underneath framed in dark base colour of body. Flight fast and powerful. In strong winds hand held pointing slightly backwards. The pale underwing is clearly visible in good light, but the whole bird often seems completely dark. Only shearwater in the region with completely dark underparts, except from dark individuals of the much smaller, and short-winged, Balearic Shearwater. The latter also shows deeper belly and less deep chest. At long distance, and/or bad weather, Sooty Shearwater may be confused with Arctic Skua or even young Gannets. Differs from Gannets by size, shorter neck and no white rump patch. Told from Skuas by bursting series of stiff wing-beats with alternating glides.
Sound:Mostly heard at breeding ground. A peculiar, rhythmic, coarse moaning, with a disyllabic attack, followed by a deeper, cooing "in-breath".
Song:
Distribution:
Wikipedia: map (se also Xeno-canto below)
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCCC-photo:pablo_caceres_c, Licence,Link.
CC-photo:Jon. D. Anderson, Licence,Link.
Sounds:Creative Commons,www.xeno-canto.org,sjonnoh,http://creativecommons.org/licenses/by-nc-sa/4.0/