Appearance:

Very similar to Common Swift, and often difficult to identify in the field. Seeing the birds against a darker background, as opposed to the sky, brings out some of the characters more clearly. Generally paler and more sandy brown than Common Swift. Differs further from C. Swift by: Rounder wing tip (outermost primary shorter than the next), slightly broader wings, broader and flatter head. White throat patch bigger and more prominent. The face seems paler, which brings out the dark eye-mask. Back slightly darker than upper part of wings. More contrast between outer and inner primaries. Underparts with more pronounced scaly pattern. Flight less acrobatic, with slightly slower wing-beats, more frequent gliding and much less twinkling turns.

Sound:

Similar to Common Swift, but usually very helpful for ID. Almost di-syllabic, with marked accent on second syllable which rapidly drops in pitch, "srrrree-aah". Common swift has a more even call, with accents on first part, without the sudden pitch-drop.

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

CC

Sound recording:Creative Commons,www.xeno-canto.org,Carlos W.,http://creativecommons.org/licenses/by-nc-sa/4.0/

Appearance:

Differs from Common and Arctic Tern by; noticably shorter wings, longer streamers, much paler grey upperparts, pure white underparts (faint rosy wash not very conspicuous), black bill (red base in breeding birds), dark outer primaries and no dark edge to inner primaries. Amount of red in bill increases as breeding season progresses, but also varies geographically. Wingbeats shallower and much quicker than in Common and Arctic Tern. Fishes with characteristic diagonal dives. Despite the long streamers, the birds appear short-tailed in flight, but head and bill are long and slender. The pale plumage, dark bill and giss recalls a small Sandwich Tern. Adult winter plumage with all dark bill and white forehead. Juveniles resembles juvenile Sandwich Terns, with more complete dark cap than Arctic and Common, and much more contrasting markings on back (especially to wings).

Sound:

Extremely harsh calls. Like mix of Caspian and Arctic Tern. Very hard and raspy "kreeeet", harder and higher pitched than Caspian Tern, but equally harsh. Other calls include more Arctic/Common tern-like short "kek", and similar.

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

CC

CC-photo:USFWS/Southeast, Licence,Link.

CC-photo:Werner Witte, Licence,Link.

CC-photo:Anita363, Licence,Link.

CC-photo:Mike Prince, Licence,Link.