Species and Races.
Common Characters. Tail more or less white basally; inner webs of the primaries white, without bars, anterior to their emargination. Head and neck with longitudinal streaks of whitish and dusky (except in melanistic individuals of lagopus var. sancti-johannis).
1. A. ferrugineus. Wing, 15.90–17.60; tail, 9.50–11.00; culmen, 1.00–1.20; tarsus, 3.10–3.45; middle toe, 1.40–1.65. Bill wide, the base very broad and depressed. Beneath, continuous pure white, without conspicuous spots, except sometimes a few scattered ones along the sides and across the abdomen; breast immaculate, or with only narrow shaft-streaks. Upper parts always with more or less rufous. Adult. Upper parts and tibiæ fine rufous, the former with longitudinal spots, the latter with transverse bars, of blackish. Secondaries and primaries plumbeous, the latter with a hoary cast. Tail white, washed with pale ash, and more or less stained along the edges of the feathers (longitudinally) with light rufous; sometimes with a badly defined indication of a dusky subterminal bar. Young. Above dark grayish-brown, with only the borders of the feathers rufous or ochraceous; tibiæ white, with sparse transverse spots of dark brown. Tail white only on basal third, and on inner webs, the remaining portion brownish-ashy, with several more or less distinct darker bands. Hab. Western North America, from Arizona, California, and Oregon, east to the Great Plains.
2. A. lagopus. Wing, 15.75–18.20; tail, 8.70–10.50; culmen, .80–1.00; tarsus, 2.30–2.80; middle toe, 1.30–1.50. Bill narrow, compressed; beneath more or less spotted with dusky, which usually predominates; breast with large spots of dusky; no rufous on upper parts, nor on tibiæ. Adult. Whitish, with transverse dusky spots. On the lower parts, the dusky spots or cloudings, largest and most suffused anteriorly (on the jugulum and breast). Terminal portion of the tail with several irregular dusky bands. (Sometimes almost entirely black, varying in shade from a brownish to a carbonaceous tint!) Young. Above grayish-brown, longitudinally spotted with dusky, and more or less edged with pale ochraceous, or rusty whitish. Beneath ochraceous-white, with the spots largest and most suffused posteriorly, forming a wide, more or less continuous belt across the abdomen; markings on the jugulum and breast longitudinal. Terminal portion of the tail without transverse bars.
Spots on the jugulum, in the adult, suffused into a nearly uniform patch. Never melanistic (?). Hab. Europe … var. lagopus.[91]
Spots on the jugulum, in the adult, scattered. Frequently melanistic. Hab. North America … var. sancti-johannis.
Archibuteo ferrugineus (Licht).
CALIFORNIA SQUIRREL HAWK.
Falco ferrugineus, Licht, Berl. Trans. 1838, p. 429. Lagopus ferrugineus, Fraser, Proc. Zoöl. Soc. Lond. 1844, p. 37. Archibuteo ferrugineus, Gray, Gen. B. fol. sp. 3, 1844.—Cass. B. of Cal. & Tex. 1854, p. 104; Birds N. Am. 1858, 34.—Bonap. Consp. Av. p. 18.—Strickl. Orn. Syn. I, 41, 1855.—Heerm. P. R. R. Rept. VII, 31, 1857.—Coop. & Suck. P. R. R. Rept. XII, ii, 149, 1860.—Coues, Prod. Orn. Ariz. p. 10, 1866 (anatomical notes).—Blakist. Ibis, III, 1861, 318 (Saskatchewan; eggs).—Fraser, Pr. Z. S. 1844, 37.—Gray, Hand List, I, 10, 1869. Archibuteo regalis, Gray, List B. Brit. Mus. p. 39, 1844; Gen. B. fol. pl. vi.
Sp. Char. Adult male (41,719, Fort Whipple, Arizona, Dec. 2, 1864; Dr. Coues). Ground-color of head and neck white; each feather with a medial streak of black, these growing broader posteriorly, and along the upper border of the ear-coverts are so blended as to form an indistinct stripe back from the eye. Entire lower parts (except tibia) and whole under surface of the wing continuous pure white; breast with a faint tinge of delicate ochraceous; tibia and tarsus reddish-white, tinged with or inclining to deep ferruginous on upper portion, and with numerous transverse bars of darker ferruginous and blackish; sides of the breast with a very few hair-like shaft-streaks of black; flanks with a few distant, dark ferruginous bars; axillars with two or three cordate spots of ferruginous near ends; feathers of the lining next the body, with blended irregularly hastate spots of rufous; under primary coverts shading into cinereous on terminal half, and with obscure broadly hastate spots of a darker shade of the same; primaries slaty beyond their emargination, deepening gradually toward their tips. Back, scapulars, and lesser and middle wing-coverts fine rufous, each feather with a broad median, longitudinal spot of brownish plumbeous-black, these on the back rather exceeding the rufous; longer wing-coverts and secondaries ashy-umber, with very obsolete transverse bands of darker; primary coverts more ashy, and more distinctly banded; primaries fine chalky cinereous, this lightest on outer four; shafts pure white. Rump nearly uniform brownish-black,—posterior feathers rufous with medial black blotches; upper tail-coverts snowy white on outer webs, inner webs more rufous; a few concealed blackish transverse spots. Tail pale pearly ash, becoming white basally, and with a wash of dilute rufous along the edge of outer webs; inner webs white, with an ashy tinge thrown in longitudinal washes; outer feathers nearly white, with faint pale ashy longitudinal mottlings; shafts of tail-feathers pure white. Fourth quill longest; third but little shorter; second very much shorter than fifth; first intermediate between seventh and eighth. Wing, 16.75; tail, 9.20; tarsus, 2.95; middle toe, 1.35.