200 BLUE HAWK, OR HEN-HARRIER. 
to swallowing them, an operation which they always perform 
on the ground. Morasses and level districts are their favourite 
haunts, being generally observed sailing low along the surface, 
or, in the neighbourhood of waters, migrating when they are 
frozen. ‘They build in marshy places, among high grass, 
bushes, or in the low forks or branches of trees; the female 
laying four or five round eggs, entirely white or whitish, with- 
out spots. During the nuptial season, the males are observed 
to soar to a considerable height, and remain suspended in the 
air for a length of time. 
The male hen-harrier is eighteen inches long, and forty-one ~ 
in extent ; the bill is blackish horn colour ; the cere greenish 
yellow, almost hidden by the bristles projecting from the base 
of the bill ; the irides are yellow. The head, neck, upper 
part of the breast, back, scapulars, upper wing-coverts, and 
middle tail-feathers, pale bluish grey, somewhat darker on the 
scapulars; the upper coverts, being pure white, constitute 
what is called a white rump, though that part is of the colour 
of the back, but a shade lighter ; breast, belly, flanks, thighs, 
under wing-coverts, and under tail-coverts, pure white, with- 
out any spot or streak. The wings measure nearly fourteen 
inches, and, when closed, reach only two-thirds the length of 
the tail, which is eight and a half inches long, extending by 
more than two inches beyond them ; the primaries, of which — 
‘the first is shorter than the sixth, the second and fifth sub- 
equal, and the third and fourth longest, are blackish, paler on 
the edges, and white at their origin, which is more conspicuous 
on their inferior surface ; the secondaries have more of the 
white, being chiefly bluish grey on the outer web only, and at 
the point, which is considerably darker. The tail is but very 
slightly rounded. All the tail-feathers have white shafts, and 
are pure white beneath; the middle ones are bluish grey, the 
lateral almost purely white; somewhat greyish on the outer 
vane, and obsoletely barred with blackish grey on the inner. 
The feet are bright yellow, and the claws black; the tarsus is 
three inches long, and feathered in front for an inch, 

