Great Grey Owl (Strix nebulosa)
White-winged Tern (Chlidonias leucopterus)
Approaching Eagle Owl in size, but shape more elongated, with head being extremely large. Differs from Ural Owl in yellow eyes, concentric markings in facial disks, bold white bars between eyes and black "beard". Wings and tail long. Characteristic pale patch at base of primaries shows in flight, but the species leaves an overall darker impression than Ural Owl. Tail with dark terminal band.
Sound:Song: Cyclic, repetitive, very deep calls rising and falling in volume. Accented start and end of each "hooh". As the call fades away in volume, the speed accelerates. Sometimes disyllabic "ho-ho,ho-ho,ho-ho,ho-ho".
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
CCBreeding adult easily identified by white tail/rump combined with jet black under wing coverts and silvery upper wing. Immature with brownish back contrasting with pale, silvery upper wings and pale rump. Broad white collar, and lacks dark breast patch of immature Black Tern. Adult winter most liable to confusion with other terns, but upperparts much paler than Black Tern. Contrasting dark outer primaries and secondaries to rest of wing. Often retains some black under coverts even in winter which is diagnostic if seen. Slightly more compact than Black Tern and often recalls Little gull in shape. Bill noticeably shorter and thinner than in Whiskered Tern.
Sound:Mostly silent away from breeding ground. Most diagnostic call a dry, rolling "krrrrrr-ta-ta" where the rolling is followed by one or two accentuated syllables, or just simply "krrrrrr". Used in excitement.
Call:
Distribution:
Xeno-canto: map
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCCC-sound:Marco Dragonetti, Licence,Link.