Falco pterocles, Temm., PI. Col. 1, 1823, pis. 56 (adult) and 139 (young).
Buteo pterocles, Less., Man. 1, 1828, 103.— Gray, Gen. B. I, 1849,12: Hand-
list, I, 1869, 8.— Caban., in Schomb. Guiana, III, 1848, 739.— Kaup,
Contr. Orn. 1850, 75 (subgeD. Tacky trior chis). — Burm., Th. Bras. II, 1855,
49.— Schleg., Mus. P.-B. Buteones, 1863, 13; Rev. Ace. 1873, 110.—
Pelz., Orn. Bras. 1871,3, 396.— Scl. & Sazv. P. Z. S. 1870, 782 (Andes
of Merida, Venezuela) ; Nom. Neotr. 1873, 119 (Mexico to Brazil). —
Lawk., Bull. U. S. Nat. Mus. No. 4, 1876, 41 (Tapani, S. Mexico, July).*
Tachytriorchis pterocles, Kaup, Sang. Vog. 1844, 123.— Bonap., Consp. 1, 1850,
17.
Buteo albicauda, Less., Traits, 1831, 81, pi. 15, fig. 2. — Pucheran, Rev. et Mag. Zool. 1850,214.
Buteo tricolor, Hartl., Ind. Azara, 1847, 1 (nee D'Orb.). tl Buteo erythronotus", Scl., P. Z. S. 1859,389 (Oaxaca) (ncc Kiug).— Salvin & Scl., Ibis, 1860, 401 (Antioquia, Guatemala.)— La wr., Ann. Lye. N. Y. IX, 1868, 133 (San Jose" and San Antonio, Costa Rica). il Buteo Jiarlani " (supposed young), Sharpe, Cat. Ace. Brit. Mus. I, 1874, 191 (=juvA).
HAB. — The whole of Middle America, north to the Lower Rio Grande Valley in Texas (on the eastern side), Colima (west coast), and the City of Mexico (central plateau); Eastern South America as far as Paraguay. Diagnosis.— Wing, 14.50-18.00 ; tail, 7.70-10.50 ; culmen, .95-1.05 ; tar- sus, 3.30-3.70 ; middle toe, 1.55-1.80. Form : Third quill longest ; first intermediate between sixth and eighth. Tail even in adult, slightly rounded in young. Color : Adult, tail white (the lateral feathers much tinged with ash), crossed by a broad subterminal band of black ; the white portion crossed by faint lines or narrow bars of plumbeous. Above dark plumbeous ; rump and lower parts pure white ; throat plumbeous- black or bluish-plumbeous. Flanks, rump, and lining of the wing usually faintly barred with ashy, dusky, or rufous. $ : Lesser wing- coverts with a restricted patch of rufous on the anterior portion ; longer scapulars strongly tinged with rufous. 9 : Rufous patch on lesser wing- covert region extended over nearly the whole of its area ; longer scapu- lars scarcely tinged with rufous. Young: Tail hoary-grayish (the inner webs mostly white), growing gradually darker terminally, and passing narrowly into dull whitish or rufous at tip ; crossed by numerous nar- row and very indistinct bars of darker, ttjese growing gradually obsolete towards the base.f General color brownish-black, the lower parts more or less variegated (most conspicuously on the posterior portions and on middle of the breast) with ochraceous or whitish.
EemarTcs. — The identity of specimens of the two plumages described in the diagnosis as "adult" and u young" is proven by specimens in whfbh part of the tail-feathers are of one plumage and part of the other. Such 9 specimen is in Mr. Lawrence's collection from the City of Mexico. The older individuals in the immature dress are colored as follows: — Tail hoary ash, growing darker terminally-, and passing narrowly into
- Iris hazel-brown ; cere greenish ; fe t yellow.
Fide Salvin, Ibis, October, 1874, 314.
% These bars are sometimes entirely obsolete on the outer webs.
