Appearance:

Largely unmistakable. Male almost pure white with black dots. Female and juveniles white with heavy black barring, and may seem grey at a distance. Juveniles more finely barred than adult females, giving them a greyer appearance, with white neck and face. Body barrel-shaped, head small and rounded. Wing-tips more pointed than in other owls. Flight action both buzzard and owl-like, with surprising agility. Note that several species of owls may seem completely white to the untrained eye when suddenly appearing in car headlights etc.

Sound:

Song consists of single utterances or series of "aooo", recalling Great Black-backed Gull, and is far carrying. Male warning call a deep and harsh "groat grat grat", with accented endings of each syllable. Female warning call higher pitched. Also various other high pitched calls.

Alarm 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

CC-sound:Niels Krabbe, Licence,Link.

CC-photo:ahisgett, Licence,Link.

CC-photo:Frank.Vassen, Licence,Link.

Appearance:

Unmistakable in breeding plumage, but otherwise easily confused with other marsh terns. Breeding plumage with black head and belly, but pale underwing and grey rump. When in immature and winter plumage it differs from Common and Arctic tern by smaller size and short, moderately forked tail, and from other marsh terns by slimmer body and wings (compared to White-winged tern), and relatively long, thin bill. Both immature and adult winter show dark front edge of wing, and characteristic dark shoulder patch at wing base. Back is dark in immature birds. Grey rump in all plumages. Flight usually different from Sterna-terns, with erratic dives for no apparent reason, and "aimless" change of direction. Note that when foraging over saltwater, flight becomes more Sterna-like.

Sound:

Moderately vocal. Flight call a more or less clear "kleck, or a disyllabic "klee-ake" with accented first syllable. Sometimes slightly rolling "klirr-eke", but never as much as in White-winged Tern. Also a slightly harsher "kreek", but not as raspy as in Whiskered Tern.

Flight 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

CC-sound:Ad Postma, Licence,Link.