Bittern (Botaurus stellaris)
Black Tern (Chlidonias niger)
Bulky, golden-brown heron with thick neck and short legs. Largely unmistakable but skulky behaviour makes it difficult to observe, as it generally forages hidden in reed-beds. Plumage mottled above, with coarse stripes below. Primaries and most secondaries with dark barring, in contrast to paler coverts. May recall Eagle Owl in flight with broad, rounded wings and retracted neck, but wings are bowed and legs trail behind tail. Crown and moustache stripe black in adult and brown in immature birds. Betrays its presence by it's far reaching song.
Sound:Flight call a deep croaking "graat". Song unmistakable and far reaching (up to 5 km). Pitch very deep, with timbre similar to blowing on a big empty bottle. At close range an "inbreath" is also audible (1-3 dampened, higher pitched introductory notes).
Song (note; recording not audible on small mobile devices):
Distribution:
Wikipedia: map (se also Xeno-canto below)
Ecology:Birdlife ecology
Links:
Observation.org Latest observations
Image search Flickr NB! May give other species
CCUnmistakable 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