Circus macrourus
Slender 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".
Some calls similar to Montagu's and Hen Harrier, but display call quite diagnostic. A thin, vibrating trill "peerrrrrrrr".
Wikipedia: map (se also Xeno-canto below)
Birdlife ecology
