Montagu’s Harrier (Circus pygargus) is 43–47 cm in length with a wingspan of 105–125 cm. The male weight is about 260-265g while the female is 340 to 345 g. Its graceful flight is characterized by powerful and elegant wingbeats, giving the impression of buoyancy and easy flying. During the breeding season and in winter quarters, it can be both solitary and gregarious at times. There may be as many as 30 nests in the same area that are associated with one breeding pair, sometimes within a 10-meter distance.
The more widespread of the two smaller harriers and soars and glides with wings held in shallow V. Adult male separated from adult male Hen or Pallid by darker grey, less cleanly patterned appearance with two black bands on the underside of secondary’s and one on the upper side and reddish-brown streaks on flanks and underwing coverts. As is necessary for harriers to maintain a positive dihedral on their wings, it searches the countryside low and generally holds its wings at a positive angle.
Has solid black wingtips, unlike Pallid, and often appears longer winged than the latter owing to broader wingtips. Noticeably slimmer than Hen, with longer, narrower, more pointed wings (wing point formed by 2nd–4th primaries instead of 2nd–5th), longer tail (noticeably longer than wing breadth), gray (instead of white) upper tail coverts, and lighter, more buoyant (almost tern-like) flight with rather wavering glides.
The body rises and falls rhythmically during a softly flapping flight. General coloration varies from medium ash-grey in most to rather pale ash-grey in some older individuals. The adult female told from female and juvenile male Hen by same structural and flight differences as for adult male, by more conspicuous dark crescent on ear-coverts and (more often than not) by lack of any pale collar (narrow collar present in Hen). For differences from very similar adult female Pallid, see that species.
Juvenile more easily separated by unstreaked and rich rufous underbody and underwing coverts, and by noticeably darker underside to secondaries. (Beware, however, rare juvenile Hen with quite rufous underparts and little or no dark streaking.) For differences from similar juvenile Pallid, see that species.
The juvenile Montagu’s Harrier resembles an adult female, but has largely unstreaked rich rufous or sometimes yellowish-orange underbody and underwing coverts, reduced barring on underside of primaries, more prominent dark crescent on ear-coverts, and, usually, darker secondaries. In sub-adult males, the grey areas are a dingy brownish-grey, darker than in adults.
Montagu’s Harrier is usually a silent bird but, the display calls a loud, sharp, rapidly repeated ‘kniakk-kniekk-kniekk’ and the alarm calls a similar but more shrill ‘chekk-ekk-ekk-ekk…’. Also, the begging calls of the female a plaintive, whistling ‘psiii’. Circus pygargus, also known as Montague’s harrier, is a family of harriers that migrates south. George Montagu, an English naturalist, is the common name of the species.
A bird of prey has a rare dark morph that could be mistaken for a dark-morph adult or dark juvenile Western Marsh, but is noticeably smaller and slimmer bodies, with longer, much narrower, and more pointed wings, longer, narrower tail, and different flight action. Instead of the conspicuous whitish bases to primaries and secondaries (and in the same way colored under primary coverts) present in dark-morph Western Marsh, shows silvery-grey bases to primaries (sometimes absent in male and sometimes barred with dark in female).
The female and juvenile birds have strongly banded tails (bands absent or faint in Western Marsh), but the adult males may show little or no banding. It is Long-distance migration is the hallmark of Montagu’s harriers. Eastern birds migrate to India, while birds from the southeastern part of the range spend the winter in Africa.
Generally uncommon and local (In addition to map range, has bred Britain, Finland.) Open country, either flat or rolling, in grassland, low crops, heathland, moorland, marshes, dunes, and young conifer plantations.
Related Reading – Facts of Cooper’s Hawk