(_Normal young plumage._)
_Buteo oxypterus_, CASS. P. A. N. S. VII, 1855, 282.—IB. Birds N.
Am. 1858, 30.—STRICKL. Orn. Syn. I, 1855, 28.—COUES, P. A. N. S.
1866, 9.—GRAY, Hand List, I, 8.—COOPER, Birds Cal. 1870, 480. _Buteo
albicaudatus_, “VIEILL.,” SCLATER, P. Z. S. 1869, 634, No. 22.
(_Melanistic plumage._)
_Buteo fuliginosus_, SCLATER, P. Z. S. Lond. 1858, 356.—IB. Trans.
Z. S., July, 1858, 267, pl. lxii.—RIDGWAY, P. A. N. S. Dec. 1870, 142.
SP. CHAR. _Adult; melanistic plumage_ (No. 12,117, Mazatlan, Mexico;
Colonel Abert). Entirely fuliginous-black, darkest on head and back; no
white on forehead. Tail cinereous-umber, crossed with seven very regular
and continuous bands of black, the subterminal one of which is broadest.
Lower tail-coverts, and larger under wing-coverts, with transverse bands
of dull white; lining of the wing unvaried black; under surface of
primaries silvery-white, that portion beyond their emargination black,
the whitish portion crossed by distant, very obsolete, transverse bars.
Third quill longest; fourth and fifth scarcely shorter, and nearly
equal; second equal to sixth; first shorter than eighth. Tail square;
scutellæ of the tarsus very faintly defined, or, in fact, scarcely
detectable (probably accidental), Wing, 13.00; tail, 7.00; tarsus, 1.95;
middle toe, 1.55.
_Young male; normal plumage_ (No. 8,550, Fort Fillmore, New Mexico;
Dr. T. C. Henry, U. S. A.). Head, neck, and lower parts, soiled
ochraceous-white. Feathers of the head above, and neck laterally and
behind, with medial stripes of blackish-brown; jugulum, breast, sides,
flanks, and abdomen, with large rounded spots of blackish-brown; tibiæ
with transverse bars of the same; lower tail-coverts almost immaculate.
A conspicuous “mustache” of blended dusky streaks, from angle of the
mouth across the cheeks, the dusky suffusing the lores. Whole oral
region scarcely variegated pale yellowish; whole chin and throat
immaculate.
Prevailing tint above, blackish-brown, becoming purplish-black on
primaries; whole outer surface of wing plain, but interscapular region
somewhat variegated with partially concealed, irregular blotches of
deeper ochraceous than the lower parts; upper tail-coverts with pairs
of indistinct white spots. Tail grayish-brown (white at extreme base),
crossed with about ten narrow, indistinct, but regular bands of dusky.
Lining of the wings yellowish-white, with sparse cordate spots of
blackish, this tint prevailing over the under primary coverts; under
surface of the primaries pure purplish-black after their emargination,
but anteriorly plain hoary brown, growing paler basally. On inner webs
are very indistinct transverse spots of dusky, touching neither the
edge nor shaft of the feather, and entirely concealed when the wing is
closed. Shafts of primaries pure white on under side; on outer, dark
brown. Wing-formula, 3–4–2–5–6–7–1, 8. Three outer primaries emarginated
on inner webs; second, third, and fourth, sinuated on outer. Wing,
13.70; tail, 7.00; tarsus, 2.10; middle toe, 1.35. Primaries project
beyond secondaries, 5.50. (Cassin’s type.)
[Illustration:
=12117.= ½
=12117.= ½
_Buteo oxypterus_ (Mazatlan).]
_Young female_ (33,508, San José, Costa Rica; J. Carmiol). Differs from
the type chiefly in lighter colors. The whole forehead very broadly
immaculate dull white, this continuing back to the occiput in a broad
unstreaked superciliary stripe; along the upper edge of the ear-coverts
is a rusty suffusion, with condensed, fine dusky streaks, forming an
indistinct stripe separating the wholly white ear-coverts from the
supraoral stripe; the “mustache” is very conspicuous; the breast has a
few large tear-shaped spots of clear blackish-brown, and the sides have
very sparse, irregular, and more sagittate spots of the same; the whole
posterior parts are immaculate. The upper parts are more variegated
with paler, the wing-coverts and rump having the feathers irregularly
bordered with whitish. The upper tail-coverts are white, barred with
dark brown. Tail, hoary brown, crossed by nine or ten nearly obsolete,
narrow bands of dusky. Whole lining of the wings immaculate, except the
conspicuous patch on the primary coverts. The whole under surface of the
primaries is uniform slaty, gradually deepening into black towards ends.
Wing-formula, 3–4–2–5–6–7, 1. Wing, 15.00; tail, 8.00; tarsus, 2.45;
middle toe, 1.55. Primaries project beyond secondaries, 6.00.
HAB. Tropical America, from the southern border of the United States to
Buenos Ayres.
The melanistic specimen described above agrees perfectly with Mr.
Sclater’s excellent figure of his _B. fuliginosus_ above cited, and
the only discrepancy in the description is in the measurements,—those
given for the _B. fuliginosus_ being, wing 12.00, tail 6.50, and
tarsus 2.60. This difference—certainly not great—very likely indicates
the proportions of the sexes, while the discrepancy as regards the
length of the tarsus, it is probable, results from a different mode of
measurement.
The present form is very nearly related to the true _B. swainsoni_,
and, though distinguishable, we find it difficult to express points
of absolute difference. The essential distinctions, however, are the
longer primaries and lighter colors of the present bird, there being
in the immature plumage of _oxypterus_ no approach to the deep, fine
ochraceous, the characteristic and prevalent tint of the young _B.
swainsoni_. The spots beneath are more sparse, and there does not appear
to be that tendency to their aggregation on the sides of the breast as
generally seen in _swainsoni_.
Both agree, however,—and differ from all other species,—in the unbarred
slate-color of the under surface of primaries, the plain black of the
outer surface, conspicuous “mustache,” obscurely barred gray tail, etc.
In fact, the general pattern is almost exactly the same, while there is
little difference in relative proportions.
In view of the very appreciable, though rather indefinite, differences
above indicated, and the obscure history of the present bird, we prefer,
at least until more familiar with its different stages, to recognize it
under the above name.
A third specimen, from Buenos Ayres (Conchitas; William H.
Hudson),—exactly similar, in all particulars, to the two specimens
described,—was labelled by Mr. Sclater, _B. albicaudatus_, Vieill.,
which is usually placed as a synonyme under B. pterocles, an exclusively
South American species; though belonging strictly to the same section
of the genus with the present bird and _B. swainsoni_, it is quite
distinct, the Smithsonian Collection containing numerous examples
illustrating the several stages of plumage.
HABITS. Taking the two varieties together, this species appears to range
over the entire continent of America, from the Arctic regions to the
cold-temperate portion of South America. In Arctic America it appears to
have a western distribution, though extending far to the north during
the breeding-season, and being more or less nomadic during the winter. A
single well-marked specimen was taken by Mr. Brewster, in the winter of
1871–72, in the eastern part of Massachusetts. It was first noticed by
Dr. Richardson, and was by him supposed to be identical with the common
Buzzard of Europe. It was met with in the fur country, where it was
migratory, arriving there early in April, and departing again about the
end of September. It frequented the low alluvial points of land which
stretch out under the high banks of rivers, where it might be observed
sitting for a long while motionless on the bough of a tree, waiting
patiently for some small birds or quadrupeds to pass within its reach.
As soon as it perceived anything of the kind, it would glide silently
into the air and sweep easily but rapidly down upon its prey. One of Dr.
Richardson’s specimens was found to have two whole toads in its stomach.
Dr. Richardson states that this Buzzard builds its nest on a tree, of
short sticks, lining it sparingly with deer’s hair. The eggs, from three
to five in number, are described as equalling in size those of the
domestic fowl, and as having a greenish-white color, with a few large
dark brown blotches at the larger end. It was seen by the doctor as far
to the north as the 57th parallel.
Mr. Audubon’s drawing and description of this bird were taken from a
specimen obtained by Dr. Townsend from the Columbia River. A number
of specimens have been obtained by the various government exploring
expeditions. A single specimen was taken by Mr. Dresser near San
Antonio, in Texas.
Captain Blakiston (Ibis, 1861, p. 317) obtained several specimens of
this Buzzard at the forks of the Saskatchewan River, in the stomach
of one of which he found three toads. He states that it was quite
abundant in that neighborhood. He adds that Mr. Bourgeau procured
several specimens of the eggs, identified by also obtaining the parents.
These eggs are said to have been white, more or less blotched with red.
Mr. Bernard Ross also obtained this bird on the Mackenzie River, where
it was rare.
[Illustration: _Buteo swainsoni_ (adult).]
This Hawk was observed by Mr. Dall, in Alaska, a skin having been
obtained at Koyukuk, May 26, from an Indian. Mr. Dall states that it
prefers the thickets and woody places, is not so often seen as some of
the other species. It generally builds a very large nest of sticks, and
begins to lay about the last of April. The young are hatched out about
the 30th of May. It was only a summer visitor. He found not only the
bones of rabbits, squirrels, and mice about its nest, but also those of
ducks, and in one instance part of a white-fish.
Dr. Heermann obtained an egg of this species in Northern California,
which had a yellowish-white ground-color, marked with obscure cloudings
of a purplish-gray, and irregular patches of a light tone of umber
brown. It measured 2.31 inches in length, and 1.84 in breadth.
We are indebted to Dr. W. J. Hoffmann for the following interesting
note in relation to the nesting of this species: “On the 28th of May,
1871, we encamped on Antelope Creek, forty miles north of the Central
Pacific Railroad Station, Argenta, Nevada. The stream of water, which
is small, is fringed with willows, averaging about twelve feet in
height. Strolling along the underbrush, I came to the nest of the
_Buteo swainsoni_, which was built on the top of a willow, and in its
construction took in several distinct limbs, so as to give better
support. The nest, about two feet across and one foot in thickness,
was constructed of thin sticks and fragments of roots. The inside was
lined with leaves of tule and grass. The nest contained two eggs. Only
eight feet from this nest, on the same bush, and at the same height, a
female of _Icterus bullocki_ was on her nest. These birds appeared to be
living together in harmony, having been in constant sight of each other
for several weeks, as the condition of the eggs proved. I deem this
remarkable only as showing a rapacious and an insectivorous bird living
so closely together that one might at any time have been made the prey
of the other by a single spread of the wings.”
[Illustration: _Buteo swainsoni_ (young).]
Dr. Gideon Lincecum, of Washington County, Texas, speaks of this species
as one of the common Hawks of the Texan prairies. He states that it
nests on the ground in the prairie; lays six eggs, sometimes on tall
trees,—when it chooses to rear its young in the forest. It is apt to
pounce on a brood of young poultry when it sees them, but being rather
timid does not like to go about the houses. Its principal food is
grasshoppers, prairie rats and mice, and small birds. Dr. Lincecum has
often seen it when the grass on the prairie was burning, in the spring
of the year, constantly on the wing, in front of the fire, catching the
grasshoppers, rats, mice, and any small game that is driven out of the
grass by the crackling fire; and it will keep in the smoke so close
to the fire that it soon becomes almost as black as soot. He further
remarks that, “when any one approaches their nest on the prairie, they
will make a pretty bold attempt to frighten or decoy him away from it.
It first tries to lead the intruder off, by alighting in the grass near
by, and screeching loudly as if something was greatly the matter; you
approach him, and with much seeming difficulty it makes out to move off
a little farther, still screeching louder than before, and this piece
of deception it will repeat time after time, improving a little in its
powers of locomotion as it gets you farther from the nest, until it
judges it is far enough,—that you have lost the place in the unmarked
sea of grass,—when it seems to fly as well as ever; it circles round
once or twice, going still farther off, and settles silently down in
the deep grass. This last performance is to induce the belief that it
has returned to the nest. But if you refuse to be led astray by these
manœuvres, and remain about its nest, it will make a good fight. One
came very near knocking off my hat one day when I did not know I was
intruding on its premises.”
The _Buteo bairdi_ of Hoy is now ascertained to be only an immature
form. It was first met with in Wisconsin, and since then has been taken
in various western localities.
A pair of these birds was found by Mr. Ricksecker, breeding in this
plumage, in Utah. The nest was built in a young aspen-tree. The egg is
marked with larger and more deeply marked blotches than usual, and is
nearly of an exact oval shape, measuring 2.30 inches in length by 1.75
in breadth. The ground-color is white, with a slight tinge of rufous,
over which are diffused, over the whole surface, fine markings of a
reddish, rust-tinged brown. Besides these the larger end, and some other
portions of the surface, are boldly dashed with large blotches of the
same color, but of a deeper shade.
A black Buzzard, originally described as _Buteo insignatus_, is now
known to be only an individual melanistic condition of the species.
It was first met with in the vicinity of Montreal, and the specimen
belonging to the Natural History Society of that city was described as
new by Mr. John Cassin. A similar specimen was taken by Mr. Macfarlane
at Fort Anderson, where it was breeding. It was met with rather
abundantly by Dr. Heermann on the San Joaquin River, in California, and
seen along his route for a considerable distance. He described it as
sluggish in its habits, perching for hours in a quiescent state on some
tall tree, and permitting the hunter to approach without showing any
signs of fear.
[Illustration: _Buteo swainsoni_, var. _oxypterus_ (young).]
Dr. Cooper found this bird pretty common in the vicinity of San Diego,
in March, 1862, when they were apparently migrating northward. In their
habits they appeared to resemble the larger varieties of Buzzards. Mr.
Salvin obtained a single specimen of a Hawk at Duenas, which is referred
by Mr. Gurney to this variety (Ibis, I, 216).
The variety _oxypterus_, of this species, was first described from an
immature specimen obtained at Fort Fillmore, New Mexico. It ranges
southward throughout tropical America to Buenos Ayres.
Buteo zonocercus, SCLATER.