Arctic Tern (Sterna paradisaea)
Hen Harrier (Circus cyaneus)
Differs 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
CCIn all plumages: Glides with wings raised in shallow V. Shows 5 primaries. This makes the wing tip broader than in Pallid- and Montague's Harriers, and the wings seems shorter. (Note that moulting individuals may show only 4 primaries). Male; grey with black primaries, white rump and underparts, and broad black trailing edge to underwing. Note that subadult males may show partly black primaries like Pallid. Female; brown with white rump, barred tail and streaked underparts.
Sound:Mostly heard at breeding ground. Calls with quite soft series of "ke-ke-ke-ke". Also a wailing, squealing whistle, with emphasized first syllable.
Contact 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
CCSounds:Creative Commons,www.xeno-canto.org,Bruno Durand,http://creativecommons.org/licenses/by-nc-sa/4.0/