Common Tern (Sterna hirundo)
Hen Harrier (Circus cyaneus)
Differs from Arctic Tern in longer head, and more orangy red, rather than deep red, bill. Tip of bill usually black. Legs longer, but tail streamers shorter than AT. Underparts of primaries with diffusely bordered dark trailing edge (sharply bordered in Arctic Tern). Upper side of primaries with dark wedge (less apparent in winter). Secondaries opaque. Crest more apparent than in Arctic Tern and underside whiter. Juveniles with buff back.
Sound:Similar to Arctic Tern but deeper. Lacks latter's high pitched "tip-tip-tip" call, and the drawn out "kree-aaahh" call falls more distinctly in pitch.
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
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/