Black Tern (Chlidonias niger)
Blyth's Reed Warbler (Acrocephalus dumetorum)
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
CCSimilar to Reed Warbler but note very short primary projection, evenly coloured wings with dull tertials. Under tail-coverts almost white, with very little buff tinge. Legs overall darker than congeners. Immature birds with slightly paler legs and warmer upperparts and fringes to flight-feathers. Leaves a slimmer impression than Reed- and Marsh W., with flatter forehead and tapering bill. Posture often Sylvia-like with frequent cocking, flicking and fanning of tail.
Sound:Contact call a short and sharp Lesser Whitethroat-like "tek", different from Mars W. Alarm call a dry, rolling "krrrreet", often with a register break splitting into high register overtones. Song recalls Marsh Warbler in timbre but is generally diagnostic. Tempo slow and deliberate, pace recalling that of Song Thrush, with marked pauses. Typical articulate, arpeggio-like whistling motifs alternated by mimicry are often repeated many times. Daytime song less typical than normal song at night, with faster pace and less repetition.
Song:
Distribution:
Xeno-canto: map
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCSound recording:Recorded by Edmunds Racinskis