Arctic Tern (Sterna paradisaea)
Pallid Harrier (Circus macrourus)
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
CCSlender and elegant harrier, with narrow wings and four "fingers". Adult male easily recognized by very pale grey and white plumage, with diagnostic wedge-shaped, black wing-tips (outermost primary grey). Female and immature birds often difficult to tell from Montagu's Harrier and Hen Harrier. Adult female differs from Montagu's by lack of dark band on upper wing, and by diffuse, sooty inner underwing. Pale bands do not reach wingpit, and under coverts are darker. Differs from female Hen Harrier by noticeably slimmer wings (both hand and arm) and only 4 fingers (but beware moulting Hen Harriers). Immature similar to Montagu's with unstreaked, rufous underparts. Differs in pale tips of inner primaries, and dark half-collar and pale "boa".
Sound:Some calls similar to Montagu's and Hen Harrier, but display call quite diagnostic. A thin, vibrating trill "peerrrrrrrr".
Display 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