Long-tailed Jaeger (Stercorarius longicaudus)
Black Tern (Chlidonias niger)
Breeding plumaged adults with streamers unmistakable (streamers comprising two thirds of total tail length). Adult plumage shows less variation than in other skuas. No hint of breast band, and transition between pale belly and darker vent very diffuse. No white patches at base of primaries of underwing in adults. Juveniles easily confused with juvenile Arctic Skua, but are more slender. Wings narrower and primaries and tail longer. Juvenile Arctic Skua shows white patches at base of primaries on both sides of wings, juvenile Long-tailed only on underwing, and on first few primaries of upper. Barred rump and tail coverts in juveniles. Flight elegant and buoyant.
Sound:Calls sharp and less full-bodied than Arctic Skua, and not so mewing. Short, double-accented "kew-wev" or short "kerk" in agitation. Also a long drawn-out "keeeeaah", resembling both Arctic Skua and Common Gull.
Alarm/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
CCSounds:Recorded by Andrew Spencer,http://www.xeno-canto.org ,CC license
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
CC