366 A FIRST LIST OF THE BIRDS 
Before taking leave of feroz, I may note that although it 
is quite impossible to separate them specifically, birds from the 
Himalayas do seem to average somewhat smaller, to be more 
constantly rufous, and to have the tarsi feathered further down, 
than birds killed in the plains. There are no doubt several 
exceptions to this rule, but it is nevertheless a fact that the 
great bulk of the birds in which the tarsi were feathered for less 
than 1:9 inches (measuring to the roots and not the tips of the 
lowest tarsal plumes) were obtained in the Central Himalayas, 
while in the great majority of specimens killed in the plains of 
India the bare portion of the tarsus, measured as above, did 
not fall short of 2 inches. This difference, however, is neither 
absolutely constant, nor is if accompanied by any such 
constant difference of plumage, or in dimensions as could 
justify the separation of these hill birds. 
I am inclined to believe that these more fully tarsi-feathered 
Buzzards which were mostly procured in the hills, north of 
Simla, in Kooloo and Bussahir (and a great many of them during 
the winter) represent a permanent resident race belonging to 
these hills, in which they breed, and from which they do not, 
as arule, migrate during the cold season to the plains. 
On the other hand, I believe that the mass of the birds 
which throng the desert plains of Northern and North-western 
India breed in the Suliman range in Cabul and Beloochistan 
whence they migrate to India during the winter, and this differ- 
ence of habitat and of conditions of life is the only rational 
explanation I can offer of the general, though not absolutely con- 
stant, difference between the birds killed in the Central Hima- 
layas and the plains of India. 
In my notes on the ornithology of the first Yarkand expedi- 
tion, I expressed an opinion adverse to the validity of Hodgson’s 
species, Buteo aquilinus. L had then a single specimen of the 
species which was compared for me with the type by Mr. 
Gurney and Mr. G R Gray, and pronounced by them to be 
identical with it. Ihave still only this one specimen, but yet 
after a very careful examination of it and a comparison 
with 120 specimens of ferov, I am inclined to retract my 
former opinion and admit aquilinus as a good species. 
The points of distinction on which Mr. Blyth chiefly insisted 
were the extent to which the tarsus was feathered, and the 
reticulate character of the scutation of the foot and front and 
sides of the tarsus. 
As regards the former, I have already shown that this is not 
a character by which the bird can be separated from many 
specimens of ferow; but as regards the latter Iam bound to say 
that I think I was too hasty in my former conclusion, and 
