Part 71

Archibuteo, BREHM, 1828. (Type, Falco lagopus, GMELIN.) Triorchis, KAUP, 1829 (nec. LEACH, 1816). (Same type.) Butaëtes, LESS. 1831. (Same type.) ? Butaquila, HODGS. 1844. (Type, Butaquila strophiata, HODGS.) ? Hemiaëtus, HODGS. 1844. (Same type.)

CHAR. Similar to Buteo, but bill and feet weaker, wings longer, and tarsi feathers in front, to the toes. Bill small, compressed anteriorly, but very broad through the gape; upper outline of the cere ascending basally; nostril broadly oval, nearly horizontal. Tarsus densely feathered in front and on the sides down to the base of the toes; naked behind, where covered with irregular scales. Tarsus more than twice as long as the middle toe; basal half of the toes covered with small scales; outer toe longer than the inner; claws long, strongly curved, acute. Feathering of the head and neck normal. Wing very long; the third to fourth quill longest; first shorter than seventh; outer four or five with inner webs deeply emarginated. Tail moderate, rounded. Plumage full and soft.

The relationship of this well-marked genus appears to be nearest to Buteo and Circus, with an approach to Circætus in character of the plumage, especially the wing. The Old World species, belonging to the subgenus (?) Butaquila, numbering two or three, according to different authors, I have not seen, and consequently cannot say whether they are really congeneric with the American species or not. Exclusive of these, two species are known, both of which belong to North America, one of them (A. lagopus) being found also in Europe and Africa. These differ very considerably from each other, in the details of external structure, probably quite as much as they do from the Asiatic forms above mentioned. The following synopsis will express the differences between the two North American species, and between the American and European races of the one common to both continents.

=54338=, ♀. ½ =54338=, ♀. ½ =54338=, ♀. ½ =54338=, ♀. ¼ =41720=, ♀. ½ =54338=, ♀. ½

41720, A. ferrugineus. 54338, Archibuteo lagopus.]

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.

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.

“Length, 22.50; extent, 54.50. Iris clear light yellow; cere, edges of commissure, and feet bright yellow; bill very dark bluish horn; mouth, purplish flesh-color, livid bluish along edges.”

Adult female (41,720, Fort Whipple; Dr. Coues). Almost exactly like the male, but black spots on rufous portions of upper parts much restricted, forming oblong spots in the middle of each feather; rump almost entirely rufous, variegated, however, with black. Longitudinal lines on breast more distinct; transverse bars on flanks and abdomen more numerous; tibial and tarsal feathers wholly deep rufous or ferruginous, the bars more blackish. Third and fourth quills equal and longest; second intermediate between fifth and sixth; first equal to eighth. Wing, 17.25; tail, 9.75; tarsus, 2.95; middle toe, 1.40. “Length, 23.25; extent, 56.50. Iris light ochraceous-brown.”

Young female (6,883, Los Angeles, California; Dr. Heermann). General plumage above, grayish-brown; interscapulars, scapulars, lesser and middle wing-coverts, and feathers of head and neck, edged laterally with light rufous; secondaries passing broadly into pale ashy at ends; primaries slaty-brown, with obscure darker bands; no appearance of these, however, on secondaries; rump entirely blackish-brown; upper tail-coverts wholly white. Tail hoary slate, basal third (or more) white, the junction of the two colors irregular and broken; tip obscurely paler; feathers obscurely blackish along edges, and with obsolete transverse spots of the same; white prevailing on inner webs. Beneath entirely pure white, scarcely variegated; tibiæ and tarsi with a few scattered small transverse spots of blackish; flanks with larger, more cordate spots of the same. (Breeds in this plumage.)

HAB. Western North America from California to the Missouri, and from the Saskatchewan to Texas.

Localities: Texas (Fort Stockton), (DRESSER, Ibis, 1865, 325); Western Arizona (COUES. Pr. A. N. S., 1866, 40).

LIST OF SPECIMENS EXAMINED.

Nat. Mus., 10; Philad. Acad., 2; Boston Soc., 2; Coll. R. Ridgway, 2. Total, 16.

Measurements.

+----+-----------+-----------+---------+---------+-----------+----------+ |Sex.| Wing. | Tail. | Culmen. | Tarsus. |Middle Toe.|Specimens.| +----+-----------+-----------+---------+---------+-----------+----------+ | ♂ |15.90–17.00| 9.50–10.50|1.00–1.18|3.10–3.45| 1.40–1.50| 6 | +----+-----------+-----------+---------+---------+-----------+----------+ | ♀ |17.00–17.60|10.50–11.00|1.08–1.20|3.20–3.40| 1.60–1.65| 6 | +----+-----------+-----------+---------+---------+-----------+----------+

The variations in this species are very slight, and never sufficient to mislead the student. One specimen (26,590, ♂; Fort Tejon, Cal.; J. Xantus) differs from the adults described in having the abdomen quite closely barred, the streaks on the breast distinct, the rufous above tinging the secondary coverts, and spreading over the upper tail-coverts, while the tibiæ and tarsi are of a very deep ferruginous,—the bars black.

In a specimen from the Platte (5,577, ♂; W. S. Wood) white prevails on the tibiæ, the bars being dark ferruginous upon a white ground; the flanks are similarly marked, the other lower parts, however, immaculate; there is much concealed white on the scapulars. The rufous tinge of the tail is very deep, while there is a transverse series of black blotches, indicating the course of a transverse band near the end.