+----+-----------+-----------+---------+---------+-----------+----------+ |Sex.| Wing. | Tail. | Culmen. | Tarsus. |Middle Toe.|Specimens.| +----+-----------+-----------+---------+---------+-----------+----------+ | ♂ | 9.00–9.30| 8.00–8.50| .65–.00|2.45–2.65| 1.55–1.60| 7 | +----+-----------+-----------+---------+---------+-----------+----------+ | ♀ |10.20–11.00| 9.00–9.80| .75–.80|2.60–2.75| 1.65–1.85| 12 | +----+-----------+-----------+---------+---------+-----------+----------+ Var. mexicanus, SWAINSON. MEXICAN BLUE-BACKED HAWK. _Accipiter mexicanus_, SWAINS. F. Bor.-Am. II, 1831, 45.—JARD. (ed. WILS.) Am. Orn. II, 1832, 215.—BONAP. Consp. 32 (under _A. fuscus_).—CASS. B. Cal. & Tex. 96.—IB. P. A. N. S. 1855, 279; Birds N. Am. 1858, 17.—COOP. & SUCKL. P. R. R. Rep’t, VII, ii, 1860, 146.—COUES, P. A. N. S. Philad. 1866, 18.—GRAY, Hand List, I, 1869, 33. _Adult male_ (12,024, Fort Tejon, Cal.; J. Xantus). Forehead, crown, and occiput plumbeous-black, feathers of the latter with basal two-thirds snowy-white, partially exposed. Upper plumage deep plumbeous, darkest anteriorly, the back being scarcely lighter than the nape; rump fine bluish-plumbeous. No concealed white on the upper parts. Tail brownish-plumbeous, narrowly tipped with pure white, and with four sharply defined broad bands of black,—the first of which is faintest, and concealed by the coverts, the last broadest; shafts of tail-feathers deep brown throughout. Primaries and secondaries much darker than the tail, more bluish; less so, however, than the scapulars. Lores whitish, quite in contrast with the black of the forehead; cheeks and ear-coverts dark ashy, slightly washed with reddish, and with obscure darker streaks; chin and throat white, with sparse hair-like shaft-streaks of black. Breast, abdomen, sides, flanks, and tibiæ fine vinaceous-rufous; feathers (except on tibiæ) with fine hair-like shaft-streaks of black (much narrower than in _cooperi_); breast, abdomen, sides, and flanks with pairs of transverse ovoid white spots, not touching the shaft; on the abdomen the white and rufous bars are of about equal width; on the tibiæ the rufous is deepest, and exceeds the white; anal region barred with rufous, more faintly than the abdomen; lower tail-coverts snowy-white. Sides of the neck deep reddish-ashy, this washing the whole side of the breast. Lining of the wing reddish-white, with numerous crowded, cordate, somewhat blended spots of rufous; larger coverts transversely spotted with blackish; under side of primaries silvery-white (blackish for about the terminal inch), crossed with quadrate spots of blackish, of which there are about seven on the longest quill (fourth); the basal ones are, however, so much broken, that the number varies in different individuals.