National Museum, 2; Philadelphia Academy, 2. Total, 4.
There can be but little doubt that this plumage denotes a younger
stage of the same species as the _B. zonocercus_ of Sclater. The adult
bird described above is moulting, and two tail-feathers of the old
plumage, which have not yet been cast, are precisely like those of this
specimen, the new ones being entirely different, as will be seen by
the description. Taking with this the exact similarity of the pattern
of under side of primaries, as well as the plumage in general, and the
sameness of proportions, one cannot but be convinced of their identity.
The localities of the two specimens are also so near that it is scarcely
possible they are distinct.
The plumage of this stage is parallel, in its relation to the adult,
with that of the young of _B. albifrons_ var. _minutus_, both differing
from the mature stage in nearly the same particulars, the more numerous
bands on the tail distinguishing the young of nearly all _Buteos_ from
adults of the same species.
An adult specimen from Mexico, in the collection of the Philadelphia
Academy (without number or other indications on the label), though
resembling the two specimens described, in all essential points, differs
from them in regard to the coloration of the tail. The main differences
are as follows: Tail deep black basally and subterminally, the tip (very
narrowly) and a middle zone about 2.00 inches broad, and 1.80 from the
tip, being duller and more brownish-black, this irregularly defined
anteriorly, but of sharp regular definition along the posterior border;
the subterminal black band is very precisely defined on the inner webs,
and anterior to this nearly the whole inner web is white, irregularly
blotched with black towards the base, however; the markings of somewhat
longitudinal direction; the outer webs are black to the very base. Wing,
16.50; tail, 9.00; tarsus, 2.70; middle toe, 1.80. Wing-formula, 4,
3–5–2–6–7, 1.
Whether this is a progressive stage of plumage or a mere individual
peculiarity, I do not feel certain, but am inclined to the latter
opinion. Both this specimen and the immature one described are labelled
_B. albonotatus_, Gray; I have been unable to refer to Gray’s original
description; if there is no doubt of its being pertinent to the immature
stage described, then this will be the name of the species, as it has
priority; I should much regret, however, to discard the very appropriate
and characteristic name _zonocercus_, for the other, as Mr. Sclater’s
species is so satisfactorily described and accurately figured, while the
original description of _albonotatus_ is very meagre and difficult of
reference.
[Illustration: _Buteo zonocercus_ (adult).]
HABITS. This Hawk is a Mexican and Guatemalan species which occasionally
strays into our borders in Arizona and in Southern California. Dr.
Cooper was the first of our naturalists to meet with this species within
the United States, shooting an individual on the 23d of February, 1862,
thirty miles north of San Diego, and within five of the coast. It was
associating with specimens of _B. insignatus_ and other Hawks wintering
there, and seemed rather sluggish and tame. He saw no other Black Hawks
in that neighborhood. Two years afterwards, September 24, 1864, Dr.
Coues also procured a single specimen on the Gila River. He regards the
species as restricted, within our borders, to the warm valley of the
Gila and the Lower Colorado. We possess no information in regard to
any distinctive specific habits it may possess. This species was first
described by Dr. Sclater from a Guatemalan specimen.
The bird described as _B. albonotatus_ is presumed to be identical with
this species. It was observed by Mr. Salvin on the southern slope of the
Cordillera, in Guatemala, which appears to be the true habitat of this
species, but even there it cannot be said to be common. He states that,
like many others of its class, it is a feeder on beetles and locusts.
Buteo lineatus, GMELIN.
Var. =lineatus=, GMELIN.