Wallcreeper (Tichodroma muraria)
Arctic Tern (Sterna paradisaea)
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
CCDiffers from Common Tern in shorter head, and blood-red bill. Legs shorter, but tail streamers longer (extends well past wings in sitting birds). Underparts of primaries with sharply bordered dark trailing edge (diffusely bordered in Common Tern). Both primaries and secondaries transparent to sunlight. Crest less apparent than in Common Tern and underside greyer. Cheeks white just below the black cap, often in contrast to grey lower cheeks. Juveniles lacks buff coloured back.
Sound:Similar to Common Tern but higher pitched. Typical call a series of high pitched "tip-tip-tip", and longer, ringing, high-pitched "kriiiiii" calls. The drawn out "kree-aaahh" call falls less distinctly in pitch than Common Tern.
Calls:
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