392 
BLUE HAWK, OR HEN-HARRIER. 
in almost every part of tlie globe ; and not only does it seem 
to have been considered every where distinct, but nearly every 
Wilson was of opinion that they were the same, but only judged fi'om descrip- 
tions, being unable to obtain specimens from Britain for comparison. The Prince 
of Musignano thinks they are the same, and repeats the asseveration in his latest 
correspondence, but still perceives some differences of habit, and in the changes 
of plumage, that would weigh far, if something more decided could be establish- 
ed. Mr Swainson and Dr Richardson describe it with a query, under the name 
of C. AmericanuSi and give numerous measurements of specimens, which neither 
agree with each other, or generally with those of Britain. Though I cannot at 
present fix on characters, I strongly suspect that North America will at least 
possess one species distinct from that of Eui’ope, 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 Ame- 
rican 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, Montaguiy &c. 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 considerable capacity, exhibiting the 
form adapted for a buoyant rather than rapid flight ; the tail ample. 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 dis- 
trict they inhabit. In a country possessing a considerable proportion of plain 
and mountain, where I have had the greatest opportunities 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 coun- 
try. For several days previous to commencing their nest, the male and female 
