Swift (Apus apus)
Gyrfalcon (Falco rusticolus)
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
CCLargest falcon. Heavily built. Grey upperparts and white, speckled underparts. Juveniles with browner plumage than adults, blue-grey legs and longitudinal streaking below. Diffuse moustache-stripe, and the whole head seems dark at distance, lacking a defined cap. Rounder and broader wings, longer tail and bulky belly distinguishes it from Peregrine. Underside of wings with dark coverts in contrast to pale base of flight-feathers. Extremely powerful, but slower flight action than Peregrine.
Sound:A coarse, drawn out, Peregrine-like "kaaawt", with emphasis on ending, is repeated in series. Much slower paced than in small falcons, and deeper and with different attack than in Peregrine. Also shorter, coarse warning-calls.
Alarm call:
Distribution:
Xeno-canto: map
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCSounds:Recorded by Andrew Spencer,http://www.xeno-canto.org ,CC license