Great Grey Owl (Strix nebulosa)
Black Tern (Chlidonias niger)
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
CCUnmistakable 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
Image search Flickr NB! May give other species
CC