176 ON THE CLASSIFICATION OP BIRDS. 
serine bird. Could we magnify, for instance, the nest 
of a chaffinch to the same dimensions as that of an 
eagle, it would appear just as coarse, the delicate grass 
and moss of the one would be as thick as the twigs and 
sticks of the other ; the difference, in short, is not in 
the degree of skill that is employed, but in tbe materials 
which are used; and these latter are proportioned to 
the size and weight of the bird which is to lodge within. 
There is as much difference, in point of delicate mate- 
rials, between the nest of the chaffinch and the hum- 
ming bird, as between the former and that of the crow ; 
and it would be utterly out of character that an eagle 
should construct its habitation of moss, lichens, and 
such slender materials as could not possibly support 
tbe weight it was intended to bear. We merely intro- 
duce these remarks to do away with the impression 
certainly erroneous — that because the nests of eagles 
and some other large birds are “ rude,” that is, of strong 
materials, they are consequently ill or carelessly made. 
It would seem, from all we can gather from authors, 
that the nests of eagles are exposed, that is, built either 
on the loftiest trees, or upon the ledges of rocks ; such, 
at least, arc the situations chosen by the golden and the 
white-headed eagle : of the latter. Dr. Richardson says, 
that it makes a “ rude nest of sticks, lined with hay, 
on the ledge of some inaccessible rock, generally over- 
hanging a rapid (the reach of a river), or in a lofty 
and solitary tree.”* The typical falcons, on the other 
hand, build tbeirs in the natural excavations of old 
trees : this has been observed of the kestrel ; and 
Wilson, speaking of the Fako sparmriug, says that its 
nest is forme.l in the hollow of a tree, “ pretty high 
up, where the top, or a large limb, is broken off.” The 
Accepitrine hawks, closely allied to the last, choose the 
same situations ; but in what manner that is, the de- 
gree of skill — the nest is made does not appear. In- 
deed, it may be even questioned whether they fabricate 
any nest ; for birds which, like the kestrel, breed in the 
* Northern Zoology, vol. il. 
