(1791) Circus pygargus,
Falco pygargus Linn., Syst. Nat., 10th ed. i, p. 89 (1758) (England). Circus cineraceus* Blanf. & Oates, iii, p. 383.
Vernacular names as for the preceding bird.
Description.— Adult Male. Similar to the Pale Harrier but a much darker grey without any brown tinge in old birds and with less in the younger males; the chin, throat and breast are rather dark blue-grey, this colour sometimes extending onto the abdomen, which, however, together with the flanks, vent, thigh- and under tail-coverts are white or very pale grey with rufous central streaks; the first five primaries are blackish with a grey tip but no white on the bases ; remaining primaries grey like the secondaries with white edges to the tips.
Colours of soft parts. Iris yellow, browner yellow in the female and brown in the young of both sexes ; bill black ; cere greenish-yellow ; legs and feet yellow.
Measurements. Wing 344 to 395 mm.; tail 213 to 241 mm.; tarsus about 55 to 65 mm.; culmen 23 to 25 mm. The sexes do not differ in size.
Female. Similar to that of the Pale Harrier but darker both above and below : the rufous edges to the feathers of the head and wing-coverts darker and the central dark streaks on the lower plumage broader and darker; on the upper tail-coverts the white is less in extent and is in regular bars; the ruff is less distinct.
Young birds are very like those of the Pale Harrier but are barker and more richly coloured and the ruff is very indistinct.
It is, however, easily distinguished at all ages by the notch on the outer web of the secondary primary being distant an inch or more from the coverts.
Distribution. The greater part of Europe, Northern Africa and Western Asia. In Winter it occurs throughout the Himalayas to Burma and China and to the foot-hills and adjacent plains. It also occurs, though rarely, as far South as the Northern Bombay Presidency, Central Provinces and Orissa.
Nidification. Montagu's Harrier breeds from the end of April to early May, making a bulky nest of grass, rushes and reeds, either in a bed of rushes or actually on the ground in or near a swamp. It also breeds in heather and its nest has been found in cornfields and occasionally in waste plains. The eggs number four to six and are generally unspotted bluish-white, rarely faintly marked with blotches of light red, one clutch in a hundred perhaps being more heavily marked still.
Habits. This Harrier is a very common visitor to the extreme North of India in Winter, when it may be seen lazily floating on outspread wings or napping slowly over the surfaces of open swamps, rice-fields, etc., keeping within a few feet of the surface and every now and then dropping down on to some large insect, mouse, frog or similar article of food. Small items it eats as it flies but a mouse or frog is carried to the top of the nearest bank or mound and there devoured at leisure. It sits nearly always on the ground and rarely perches on trees or even posts.