BLUE HAWK, OR HEN-HARRIER. 289 
in almost every part of the globe; and not only does it seem 
to have been considered everywhere distinct, but nearly every 
North America will at least possess one species distinct from that of 
Europe, and that the real European one, from -its close alliance, is yet 
confounded with it ;—there is no bird where I have found so much 
variation in the dimensions. I have always observed the American 
birds larger than those of this country, and the tarsi stronger and pro- 
portionally longer. In America, the species seems remarkably abundant, 
and certainly differs slightly in habit, &c.; but it is well known that 
animals, as well as birds, will accommodate themselves to a difference 
of circumstances, 
The group to which this species belongs is intimately connected on 
both sides by, as it were, intermediate species—on the one by Astur, on 
the other by Buteo. Those true to the type are, however, at once known, 
and may be named as that now under discussion, the C. histrionicus, 
Montagui, &e. It seems distributed over the world. The colours and 
changes of plumage in all are very similar ; both sexes are clothed with 
the same livery until after the second moult, and are so similar as hardly 
to be distinguished, except by the difference of size. In the males, the 
change is to shades of grey; in the females, to a lighter tinge of the 
reddish or darker browns, which appear to be the prevalent colours of 
the whole. The feathers of the rump assume a different colour, generally 
pure white, and show a prominent bar or band during flight. Their 
form is long and slender, and of no great power ; the wings are of con- 
siderable capacity, exhibiting the form adapted for a buoyant rather 
than rapid flight; the tailample. When sitting on the ground or on 
a rock, for they very seldom perch on trees, the attitude is very erect, 
like that of the sparrow-hawks ; but the most remarkable feature is the 
owl-like disk which surrounds the face, and is, in fact, nearly similar to 
that in the long-tailed hawk-owls. 
The habits of those in Great Britain differ considerably according to 
the district they inhabit. In a country possessing a considerable pro- 
portion of plain and mountain, where I have had the greatest oppor- 
tunities of attending to them, they always retire, at the commencement 
of the breeding season, to the wildest hills, and during this time not 
one individual will be found in the low country. For several days 
previous to commencing their nest, the male and female are seen soaring 
about, as if in search of, or examining, a proper situation, are very noisy, 
and toy and cuff each other in the air. When the place is fixed, and 
the nest completed, the female is left alone, and, when hatching, will 
not suffer the male to visit the nest, but on his approach rises and drives 
him with screams to a distance! The nest is made very frequently in 
a heath-bush by the edge of some ravine, and is composed of sticks, 
VOL, IIL. Ty 
