FALCONID M.—FALCONS.
In contemplating the diurnal birds o f prey, arranged by Linnaeus under the
genus Falco, we can be at no loss to discover the two typical forms in the Toothed-
billed Falcons and the Sparrow-hawks. Their peculiarities did not escape the
notice even of the earliest systematic writers, and the moderns have only confirmed
the justness of the distinction. But, with regard to the remaining groups, much
diversity of opinion still exists ; not, indeed, as regards the leading divisions, for
here likewise the ancients had long ago anticipated our distinctions between the
Eagles, Kites, and Buzzards. It is not, therefore, to these groups, taken per se, that any doubts can attach on their respective peculiarities, but rather as to
their relative rank with those that are considered typical. These doubts can only
be solved by analysis. Were our national or public museums sufficiently rich in
species of this family, to allow of this being done, we might hope to gain just
conceptions of nature; but such materials are not at present within the reach of
our ornithologists. Indeed, so lamentably deficient are our sources of information
on this head, “ that, of near three hundred described species, not a sixth part is
to be consulted in the national repository of this kingdom In such a state
of things, it is obvious that all attempts to characterize the minor types of
form, or to detect the true series of natural affinities, must be viewed with great
caution, and lie open to much objection, particularly when opposed to other
opinions, founded upon an intimate acquaintance with forms, not in our museums.
But if our ideas on the characters and value of the different groups, and on their
natural combinations, are, from necessity, so imperfect, still more hazardous is it
to attempt the location of species from the mere descriptions and figures to be
found in books. We may, indeed, make some approximation to truth, by thus
bringing together species which, in many cases, are obviously allied; but the
situation of by far the greater portion must be problematical: and, unless we distinctly
state how far we have been guided by actual examination, and how far by
mere supposition, the reader who wishes to know upon what points he may place
reliance, and upon what he may safely doubt, is left completely in the dark.
It is from an attentive consideration of these difficulties, that we have been
Zool. J o u r n i., p. 311.
induced to dissent from several modern writers in our opinions upon this family.
That the various forms of which it is composed, exhibit, as a whole, a circular
succession of affinities, has been sufficiently proved ; but the true series of the
secondary groups, among themselves, has not yet been made out. The reason
is obvious f§-the British school of naturalists, as before stated, want the means,
while those of the continent (possessing, in their superb museums, the greatest
advantages) have not the inclination to undertake the enquiry. Yet our inability
to state in what way the Falcons or Hawks form their own respective
circles cannot militate against the belief, that such is their true distribution.
It remains, therefore, to be considered, whether there is presumptive evidence
to believe that the three remaining divisions, namely, the Buzzards, Kites, and Eagles, form one circular group, independent of their affinity to the two
former. The true Buzzards, of which the Vulgaris and the Lagopus may probably
be types, are slender, long-winged birds; the bill is small, short, and
considerably curved: in this structure they agree with the true Falcons, yet
they are well known to be distinguished from them, by wanting the toothed-bill,
and by the shortness and graduated abbreviation of the exterior quill-feathers.
Now, if Nature had proceeded in a simple course, from the Buzzards to the
Falcons, we should have had birds uniting the distinctions of both, variously modified.
Both these groups being composed, in their typical examples, of slender
long-winged birds, with short bills, any species exhibiting the reverse of such characters,
and intervening between the two forms, would certainly appear anomalous,
on the supposition of a simple series of affinities being aimed at. Yet, that
such birds are to be found, even among the few that we are subsequently to
notice, is unquestionable. Let us, then, take the Buteo borealis, which, as being
more allied to the Falcons than to the Kites, may be considered an intervening
form between the Buteo vulgaris and Falco. We here see a large-sized, heavy
bird, with shortened wings, not reaching to more than half the length of the tail;
while the elongated bill, unlike either that of Buteo or Falco, obviously assimilates
to that lengthened form which belongs to the Eagles. Now, upon the supposition
that a bird so constructed is intended to fill up the interval between
Buteo and Falco, and at the same time to unite the former with the Eagles, the
singularity of its structure is no longer surprising: but if we consider it with a
simple reference to the passage between Buteo and Falco, we are almost tempted
to suspect that, in this instance, a real saltus has been made. While upon this
subject, we may cite an acute observation made by Prince C. Buonaparte, that
“ the Borealis is almost as much an Astur of the first section, as a B u t e o a
c