?? Buteo albonotatus, G. R. Gray, Isis, 1847, p. 329. Buteo zonocercus, Sclater, Trans. Zoöl. Soc. Lond. IV, pt. vi, 263, 1858.—Coues, Pr. A. N. S. 1866, 46.—Elliot, Birds N. A. pl. xxxiii.—Gray, Hand List I, 8, 1869.—Cooper, Birds Cal. 1870, 479.
52763, ♂. ½
52763, ♂. ½
52763, ♂. ¼
Buteo zonocercus.
Sp. Char. Adult (36,872, Hassayampa River, Arizona Territory, August; Dr. Coues). Entirely carbonaceous black; forehead pure white, and feathers of occiput, neck, and breast the same beneath the surface; this on under parts, showing as transverse, ovate spots on webs of feathers, partially exposed. Tail black, faintly tipped with pale ashy, crossed (about 1¾ inches from the end) by a band of hoary plumbeous, nearly an inch in width; about half an inch anterior to this is another plumbeous band, about as broad as the black one which separates it from the last; and about the same distance, near the base, is another, much narrower, and less continuous ashy band. The outlines of these bands are rather irregular; and on the inner webs the plumbeous is replaced by snowy white, which, not exactly corresponding to the plumbeous of outer webs, is rather more extended, as well as more sharply defined, forming three very conspicuous transverse zones (decreasing in width towards the base like those on outer webs), observable only when the tail is spread, or from below. On the two middle feathers both webs are plumbeous and black; and on the lateral feathers, the white prevails on the inner web, the black bands being broken up into narrow zigzags. Primaries less intensely black than the back, and showing obscure transverse bands of deeper black; lining of the wing unvariegated black; under surface of primaries pale plumbeous, passing into hoary white on edges, and crossed from base to ends with very irregular, transverse bars of blackish, these breaking up into a mottling, or blended speckling, along the edges of the feathers. Owing to moulting stage, the wing-formula cannot be ascertained. Wing, 15.50; tail, 8.50; tarsus, 2.50; middle toe, 1.60. Length, 19½; extent, 47½.
Young male (52,763, Mazatlan, Mex.; Colonel A. J. Grayson). Generally similar to the preceding; feathers of neck, back, and under parts more conspicuously spotted with white beneath the surface, these spots considerably exposed on the breast and upper tail-coverts. Tail deep dark vandyke-brown, faintly tipped with paler, and crossed with numerous narrow oblique bands of black; subterminal one broadest, being about three fourths of an inch in width; the next one is not a fourth as wide, and crosses about an inch anterior to the last; the distance between the black bands diminishes towards the base of the tail, so that after the seventh of these, no more can be distinguished. Inner webs passing into whitish towards edges, this prevailing on lateral feathers. Fourth quill longest; third scarcely shorter; fifth but little shorter than third; second intermediate between fifth and sixth; first equal to eighth. Wing, 15.30; tail, 8.80; tarsus, 2.40; middle toe, 1.60. Length, 15¾; alar extent, 48. Bill black at tip, bluish-brown at base; iris dark brown.