Black Tern (Chlidonias niger)
Black-headed Gull (Chroicocephalus ridibundus)
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
CCChocolate-brown hood in adult plumage (seemingly black at a distance), but head only with dark markings in winter and juvenile plumages. Underparts of inner primaries dark grey. First few primaries white with black tip, both on upper side of wing and under. Last character conspicuous in all plumages, but slightly less obvious in juveniles due to larger dark area of wing-tip. Slender-billed Gull and Bonaparte's Gull show similar white first primaries, but differs in long and slender head profile and white underparts of hand respectively.
Sound:Quite vocal, especially at breeding ground. Distinct, harsh calls. A rasping "kreearr", and shorter, sharp warning calls; "kek".
Contact call:
Distribution:
Xeno-canto: map
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CC