The eggs, however, differ essentially in size from those mentioned by Capt. Blakiston, and it is quite possible that Dr. Heermann was mistaken in his identification. One of these eggs was figured in the North American Oölogy, and resembles much more an egg of Swainson’s Buzzard than any egg I have since seen of this species.

The specimens procured by Mr. Kerr were taken in the Tulare Valley, in January, 1846, and are stated in his notes to have been remarkably fat, and in excellent condition generally, so that some of his party shot these birds whenever opportunity offered, for the mess-kettle, and considered them very good eating.

Dr. Cooper states that in the spring and fall these Hawks abound in Southern California, migrating in summer through the interior plains of the Columbia and the Platte Rivers, at least as far north as the Dalles. He found it in winter at Martinez, and is of the opinion that few migrate beyond the State. It was usually to be seen slowly sailing over the plains, sometimes in circles, and occasionally pouncing down obliquely on its prey, which consists principally of the large ground squirrel. It rarely, if ever, attacks poultry, and limits its prey to wild animals, and is therefore a decided friend to the farmer.

Capt. Blakiston met with this bird breeding between the north and the south branches of the Saskatchewan River, April 30, 1858. The nest was placed in an aspen-tree, twenty feet from the ground, was composed of sticks, two and a half feet across, and lined with buffalo wool. The eggs were four in number. Those taken from another nest near the same locality were five in number. This nest was in a tree, and was only ten feet above a lake. Two eggs were taken by Mr. Bourgeau on the Saskatchewan Plains, July 9. These differences in seasons, from April to July, are suggestive either of great variations in the time of nesting, or of there being two broods in a season. The eggs obtained by Capt. Blakiston measured, one 2.60 by 2.00 inches, the other 2.50 by 1.95 inches, and are described as having been white with large distinct blotches and smaller specks of two shades of brown. The other was more obscurely blotched with a paler brown, and at the same time freckled all over.

An egg of this species taken by H. R. Durkee near Gilmer in Wyoming Territory, May 9, 1870, measures 2.43 inches in length by 1.95 in breadth. The ground-color is a creamy white, over which are very uniformly distributed on every part of the egg, in nearly equal proportions, blotches, plashes, and smaller markings of a dark burnt umber. The nest from which this egg was taken was composed of sticks, and was placed among rocks. The nest contained but one egg. The parent bird was secured, and there was no question as to identification.

Archibuteo lagopus, var. sancti-johannis (Penn.).
ROUGH-LEGGED HAWK; BLACK HAWK.

Falco sancti-johannis, Penn. Arct. Zoöl. pl. ix, 1785.—Gmel. Syst. Nat. p. 273, 1789.—Lath. Index Orn. p. 34, 1790; Syn. I, 77; Gen. Hist. I, 276.—Daud. Tr. Orn. II, 105, 1800.—Shaw, Zoöl. VII, 150, 1809.—Bonap. Ann. Lyc. N. Y. II, 32.—Aud. Orn. Biog. II, 381, 1831.—Giraud, B. Long Island, p. 6, 1844.—Kerr, Trans. Gmel. II, 507, 1792. Buteo sancti-johannis, Jard. (Wils.) Am. Orn. II, 287, 288, 1832.—Nutt. Man. Orn. U. S. & Canad. p. 98, 1833.—De Kay, Zoöl. N. Y. II, 7, pl. ii, fig. 3, 1844. Butaëtes sancti-johannis, Cuv. Règ. An. (ed. 1), i, 323, 1829.—Bonap. List, p. 3, 1838. Archibuteo sancti-johannis, Gray, Gen. B. fol. sp. 2, 1844; List B. Brit. Mus. p. 39, 1844.—Bonap. Consp. Av. p. 18, 1850.—Cass. Birds Calif. & Tex. p. 103, 1854.—Blakist. Ibis, III, 1861, 318 (eggs).—Kaup, Monog. Falc. Cont. Orn. 1850, p. 75.—Strickl. Orn. Syn. I, 40, 1855.—Brewer, Oölogy, 1857, 34, pl. iii, f. 28.—Cass. Birds N. Am. 1858, 33.—Gray, Hand List, I, 10, 1869. Falco spadiceus, Gmel. Syst. Nat. p. 273, 1789.—Lath. Ind. Orn. p. 27, 1790; Gen. Hist. I, 279.—Daud. Tr. Orn. II, 109, 1800. Buteo spadiceus, Vieill. Ois. Am. Sept. I, 34, 1807. Falco lagopus, Wils. Am. Orn. pl. xxxiii, f. 1, 1808.—Brew. (Wils.) Am. Orn. Syn. 648, 1852.—Bonap. Ann. Lyc. N. Y. II, 32; Isis, 1852, 1138.—Aud. Birds Am. pl. clxvi, 422, 1831; Orn. Biog. II, 377; V, 217. Buteo lagopus, Rich. Faun. Bor. Am. II, pl. xxviii, 1831.—Aud. Synop. p. 8, 1839.—James. (Wils.) Am. Orn. I, 77, 1831.—Jard. (Wils.) Am. Orn. II, p. 54, 1832.—Nutt. Man. Orn. p. 97, 1833.—Peab. B. Mass. p. 79, 1841. Archibuteo lagopus, Cass. Birds N. Am. 1858, p. 32.—Brewer, Oölogy, 1857, 36, pl. iii, f. 29.—Coop. & Suck. P. R. R. Rept. VII, ii, 148, 1860.—Coues, Prod. Orn. Ariz. p. 16, 1866. Falco niger, Wils. Am. Orn. pl. liii, figs. 1 and 2, 1808.—Lath. Gen. Hist. pp. 256, 257, 1821. Buteo niger, Steph. Zoöl. XIII, pt. ii, p. 47, 1815.—Vig. Zoöl. Journ. I, 340.—James. (Wils.) Am. Orn. I, pp. 79, 80, 1831.—Cuv. Règ. An. (ed. 2), i, 326, 1829. Buteo ater, Vieill. Nouv. Dict. Nat. Hist. IV, 482, 1866; Enc. Meth. III, 1227.

a. Normal plumage.

Sp. Char. Adult male (43,073, Fort Resolution, June; J. Lockhart). Ground-color of the upper parts dull umber-cinereous, this more rufous on the shoulders, and dull white on nape, scapulars, inner secondaries, and upper tail-coverts; rump entirely black, feathers bordered with whitish. All the feathers above with central oblong or irregular spots of black, this color predominating on top of head, and forming transverse bands across the wing-coverts and secondaries; upper tail-coverts pure white, each marked with an exceedingly irregular transverse spot of black. Tail white on basal two thirds, and narrowly, but sharply, tipped with the same; subterminal portion pale mottled cinereous, with a very broad zone of black next the terminal white, and anterior to this three narrower and more irregular bands of the same. Primaries blackish-cinereous, with obsolete darker bands. Ground-color of head and lower parts dull white; cheeks thickly streaked with black; ear-coverts and throat more sparsely streaked; forehead and sub-orbital region plain whitish. Breast with large, longitudinal but very irregular, oblong spots of dark brown, these largest and somewhat confluent laterally; lower part of breast with much less numerous and less longitudinal spots; tibiæ strongly tinged with rusty, and with tarsus, abdomen, crissum, and flanks having irregular transverse spots of blackish-brown; lower tail-coverts unvariegated. Lining of wing white, with numerous spots of black, these becoming more rusty towards the axillars; a large space of continuous clear black, covering the under primary coverts and the coverts immediately anterior; under surface of primaries and secondaries pure white, the former becoming black at ends, the latter ashy; no bars, except toward shafts, of the latter. Fourth quill longest; third equal to fifth; second intermediate between fifth and sixth; first equal to eighth. Wing, 16.50; tail, 9.00; tarsus, 2.50; middle toe, 1.30; bill, 1.30 and .90.