Wallcreeper (Tichodroma muraria)
Black Tern (Chlidonias niger)
Unmistakable. Grey, cliff-climbing bird with long, thin and curved bill. Wings with colourful pattern in carmine red, black and white spots. Habitually flicks wings when foraging (see videolink below), but still hard to spot when not flying. Flight jerky and butterfly-like, and also recalls Hoopoe. Wings appear dark from below, except for white pearls on primaries. Male with blackish throat in breeding season.
Sound:Alarm call a thin trilling "vuiirrrrrrr". Flight call one or several soft whistles, often with (very) short trill as attack or tail. Song variable in length, but main characteristic a sequence of 4-6 long, ascending whistles with timbre recalling whistling kettle. More complex and varied phrases are mixed with the long whistles. Both male and female sings.
Song:
Distribution:
Xeno-canto: map
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