Moustached Warbler (Acrocephalus melanopogon)
Black Tern (Chlidonias niger)
Small and restless species easily confused with Sedge Warbler, Acrocephalus schoenobaenus, but showing both plumage and structural differences. Plumage differs from A. schoenobaenus in; broad, white supercilium ending without narrowing, dark crown (usually appears black), pure white throat, grey ear-coverts, dark legs and warm-rufous flanks, rump and neck. Facial markings recalling firecrest. Very short primary projection and longer, more evenly rounded tail recalling Wren when raised. Bill thinner than A. schoenobaenus. Skulky behaviour, forages low in vegetation, on ground or near water surface. Some variation in both size and plumage between western and eastern subspecies.
Sound:Contact call a dry "trrrt", similar to corresponding call of Sedge Warbler. Song most resembling that of Reed Warbler (A, scirpaceus), but often includes diagnostic (unique among congeners), pure-sounding note sequence resembling crescendo of Common Nightingale (L. megarhynchos), before launching into typical Acrocephalus sounding song. This latter type can be sustained for some time without the diagnostic sequence and is more difficult to distinguish from A. scirpaceus. Note faster tempo and more variation.
Diagnostic song:
Distribution:
Xeno-canto: map
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCCC-photo:Radovan Václav, Licence,Link.
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