Buteo swainsoni, Bonap.
Var. swainsoni, Bonap.
SWAINSON’S HAWK; BAIRD’S HAWK.
Buteo swainsoni, Bonap. Comp. List, p. 3, 1838; Consp. Av. p. 19, 1850; Proc. Ac. N. S. Phil. p. 280, 1855; Birds N. Am. 19, 1858.—Heerm. P. R. R. Rep’t, II, 32, 1855.—Strickl. Orn. Syn. I, 30, 1855.—Dresser, Ibis, 1865, 324 (Texas).—Gamb. Journ. Ac. N. S. Phil. n. δ. I, 27.—Coues, Prod. B. Ariz. 9, 1866.—Blakist. Ibis, III, 1861, 317 (fresh eggs).—Gray, Hand List, I, 7, 1869. Falco buteo, Penn. Arct. Zoöl. II, 207, sp. 103 (♀ Juv.), 1785.—Aud. B. Am. pl. ccclxxii, 1831; Orn. Biog. IV, 508, 1831. Falco obsoletus, Gmel. Syst. Nat. p. 268, 1789.—Kerr, Trans. Gmel. II, 501, 1792.—Lath. Ind. Orn. p. 28, sp. 61, 1790; Synop. Supp. I, p. 30; Gen. Hist. I, p. 254, 1821.—Daud. Tr. Orn. II, 104, 1800.—Shaw, Zoöl. VII, 152, 1812. Buteo cinereus, Vieill. Ois. Am. 1807. Buteo vulgaris, Rich. & Swains. F. B. Am. p. 5, 1831.—Jard. (Wils.) Am. Orn. II, 56, 1808.—Brew. (Wils.) Am. Orn. p. 303; Synop. p. 684, 1852. Buteo montanus, Nutt. Man. Orn. U. S. & Canad. I, 112, 1833. Buteo bairdi, Hoy, Proc. Ac. Sc. Phil. VI, 451, 1853.—Cassin, B. of Cal. & Tex. pl. xli, 1854; Birds N. Am. 21, 1858.—Strickl. Orn. Syn. I, 37, 1855. Buteo insignatus, Cass. B. Cal. & Tex. p. 102, pl. xxxi, 1854; Birds N. Am. 23, 1858.—Heerm. P. R. R. Rep’t, VII, 31, 1857.—Strickl. Orn. Syn. I, 38, 1855.—Coues, Prod. B. Ariz. 9, 1866.—Bryant, Proc. Bost. Soc. X, 1865, 90 (= swainsoni). ? Buteo gutturalis, Max. Cab. Journ. VI, 1858, 17 (and eggs).
Sp. Char. Form robust and strong, like B. borealis; wings long and pointed; only three outer primaries with their inner webs cut. Feet robust, the tarsi strong. Dimensions: Wing, 14.40–17.00; tail, 8.00–9.50; culmen, .80–.95; tarsus, 2.30–2.70; middle toe, 1.50–1.70. Weight, 1½–3½ lbs. Colors: Tail dark grayish-brown with a hoary cast, crossed by numerous obscure narrow bands of a darker shade. Adult, uniform blackish-brown above; upper tail-coverts barred with white. Throat and lower parts posterior to the breast white or pale ochraceous; a broad patch across the breast uniform brown,—reddish-rufous in the male, and grayish-umber in the female,—the whole lower surface varying to entirely uniform dull brownish-black, though intermediate shades. Young, with the ground-color of the plumage soft ochraceous, or cream-color; the head, neck, dorsal region, and sides of the breast, with tear-shaped spots of brownish-black, with a faint purple reflection. Upper parts purplish-black, variegated with ochraceous, sometimes almost wholly black. Tail as in the adult, but more hoary.
a. Normal plumage.
Adult male (53,105, Truckee River, Nevada, July; C. King, R. Ridgway). Head, neck, and upper parts blackish-brown; scapulars slightly variegated with a rufous mottling; upper tail-coverts white tinged with rufous, and with transverse bars of blackish-brown, about six on each feather. Tail dark brown like the back, approaching black terminally, basally with a slight hoary cast; crossed by about ten narrow, very obscure bands of nearly black. Front and whole throat clear white, immaculate, and sharply defined against the surrounding blackish; lores dusky. Whole breast, cinnamon-rufous (forming a wide, sharply defined band), marked laterally with the brown of the neck; each feather with a shaft-line of black; rest of lower parts, including whole lining of the wing, continuous ochraceous white, the latter region unvariegated; sides with sparse, faint, transverse bars of rufous, and shaft-lines of darker. Under side of primaries light slate anterior to emargination, beyond which they are black; slaty portion crossed by very obscure bars of darker. Fourth quill longest, third scarcely shorter; second equal to fifth; first intermediate between seventh and eighth. Length, 19.75; extent, 48.00; wing, 15.40; tail, 8.00; tarsus, 2.32; middle toe, 1.60. (Weight 1½ lbs.) Bill slate-black, bluish basally; cere, and angle of mouth, light dull lemon yellow; iris deep hazel; tarsi and toes deep chrome yellow, claws black.
58505, ♀. ½
58505, ♀. ½
Buteo swainsoni (Nevada).