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.

Appearance:

Forked and fairly long tail. Clearly bigger than Storm Petrel, with more slender appearance and longer wings. Generally not as black, and shows brownish tone to plumage. The white rump patch is oval, has a weak grey center stripe, and does not reach as far down on the sides as in Storm Petrel. Light grey upper greater coverts form a wing-band. Underside of wings all dark. Flight pattern variable, with frequent changes in direction and speed. Sometimes glides like a shearwater but at other times shows surprisingly deep wing-beats. Does not patter surface, but will rest on water. Visits breeding ground only at night, and is usually only seen after storms.

Sound:

Only calls at breeding ground. A series of accentuated cooing, interrupted by a squeaky "inbreath" and a loud, absurd, fanfare-like "kaaa-ka-ka-kaaa-ka".

Calls:

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-sound:Steph, Licence,Link.