36 
GREAT-FOOTED HAWK. 
in the plate is an excellent resemblance of the original, which 
is handsomely set up in the Philadelphia Museum. 
I am indebted to Mr. Titian Peale, for the view of an imma- 
ture specimen of the Duck Hawk, which he shot near the Rocky 
Mountains; it was quite young, having just left the nest. Its 
colours were principally a dirty white, and a reddish brown; 
the patch below the eye not very conspicuous; but the charac- 
ters of the bill and feet proved the species. 
According to Temminck, the Peregrine Falcon never inha- 
bits marshy countries; but this, I presume, is a mistake, as our 
bird is remarkable for its attachment to those places which are 
affected by the water fowl; and it is well known that the latter 
abound in all tbe marshes of the coast. 
In the month of November, 1823, I procured a fine living 
specimen of the Duck Hawk, which I preserved, with the view 
of noting its change of plumage. It was a female, and was al- 
lowed the free range of a stable and garden. Notwithstanding 
my care, it lived but nine months. On dissection, I found her 
eggs very small, although she had every appearance of being 
an adult. Around the base of the heart, and near the ovaries, 
I discovered two or three round worms, of about nine inches 
in length. 
During the time that she was in my possession she did not 
moult; and the change in the colour of the plumage was but 
slight. In winter, the upper parts were dark brown, but in the 
summer there was an appearance of ash colour on the back and 
wing-coverts. The fact, that the plumage of birds undergoes a 
change of colour, independent of moulting, appears to be now 
well ascertained; and it is with pleasure that I can add my 
testimony, on this subject, to the sensible “Remarks on the 
Changes of the Plumage of Birds,” which were published in 
the twelfth volume of the Transactions of the Linnean Society 
of London. The paper in question was written by the Rev. 
William Whitear. 
My Duck Hawk never became sufficiently domesticated to 
permit me to handle her; and if an attempt were made to touch 
