Part 64

The other specimen (Menonomee Marsh, Milwaukee, Wisc., spring of 1851) is just the opposite extreme in plumage, being unusually dark, for a young bird. Beneath, the black spots are so large as to nearly cover the whole surface, while the continuity of the black of the upper part is almost unbroken. The head above, and nape, and broad “mustache” stripe from angle of mouth down to the jugulum, with nearly the whole pectoral area, unbroken black, leaving the gular region and side of the head pale, but thickly streaked. Wing, 15.00; tail, 8.80; tarsus, 2.35; middle toe, 1.50. These specimens may be said to form about the extremes of the young plumage. An Iowa skin (No. 59,052; Ricksecker) is like the average of far-western examples.

The melanistic condition bears to the normal plumage of swainsoni precisely the same relation that the black calurus, Cassin, does to the usual style of the western variety of borealis (borealis var. calurus = montanus, Cassin); the variable series, connecting these two extremes, and designated by the name borealis var. calurus, which covers the whole, finds an exact parallel in the present species.

A specimen from the Platte (5,576, ♂, August; W. S. Wood) is entirely dark rufous-brown beneath (excepting the lower tail-coverts), with the shafts of the feathers black.

This species is entirely distinct specifically from the B. vulgaris of Europe. The latter has four, instead of only three, outer primaries deeply emarginated, and is very dissimilar in every stage of plumage.

Var. oxypterus, CASSIN.

SHARP-WINGED HAWK.

(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.)

=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.

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.