Black Tern (Chlidonias niger)
Gyrfalcon (Falco rusticolus)
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
Image search Flickr NB! May give other species
CCLargest falcon. Heavily built. Grey upperparts and white, speckled underparts. Juveniles with browner plumage than adults, blue-grey legs and longitudinal streaking below. Diffuse moustache-stripe, and the whole head seems dark at distance, lacking a defined cap. Rounder and broader wings, longer tail and bulky belly distinguishes it from Peregrine. Underside of wings with dark coverts in contrast to pale base of flight-feathers. Extremely powerful, but slower flight action than Peregrine.
Sound:A coarse, drawn out, Peregrine-like "kaaawt", with emphasis on ending, is repeated in series. Much slower paced than in small falcons, and deeper and with different attack than in Peregrine. Also shorter, coarse warning-calls.
Alarm call:
Distribution:
Xeno-canto: map
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCSounds:Recorded by Andrew Spencer,http://www.xeno-canto.org ,CC license