Part 74

Aquila, MŒHR. 1752. (Type, Falco chrysætos, LINN.) Aëtos, NITZSCH, 1840. (Same type.) Hieroaëtus, 1844, and Hieraëtus, 1845, KAUP. (Type, Falco pennatus, GMEL.) Pteroaëtus, KAUP, 1844. (Type, Falco vulturinus, DAUD.) Uroaëtus, KAUP, 1844. (Type, Vultur audax, LATH.) Pseudaëtus, HODGS. 1844. (Type, Falco bonelli, TEMM.) Tolmaëtus, BLAS. 1845. (Same type.) Eutolmaëtus, BLAS. 1848. (Same type.)

=41901=, ♀. ¼ =9128=, ♀. ¼ =41901=, ♀. ¼ =41901=, ♀. ¼ =54338=, ♀. ½ =12006=, ♀. ¼ =19124=, ♀ ? ¼

9128. Haliaëtus leucocephalus. 41901 : 12006 : 19124. Aquila chrysaëtus, var. canadensis. 54338. Archibuteo lagopus (tarsus from behind).]

GEN. CHAR. Form robust and structure powerful; the bearing and general aspect that of Buteo and Archibuteo. Wing long, the primaries long and strong, with their emarginations very deep. Tail rather short, slightly rounded or wedge-shaped. Bill stronger than in the preceding genera, its outlines nearly parallel, and the tip somewhat inclined backward at the point; commissure with a more or less prominent festoon; nostril narrowly oval, vertical; skin of the cere very hard and firm. Superciliary shield very prominent. Feet very strong, the membrane between the outer and middle toes very well developed; tarsus less than twice as long as the middle toe; outer toe equal to, or longer than, the inner; claws very long and strong, very much graduated in size; scutellæ of the toes small except on the terminal joint, where they form broad transverse plates; tarsi densely feathered all round down to the base of the toes; tibial plumes well developed, loose-webbed, their ends reaching down to or beyond the base of the toes. Feathers of the nape and occiput lanceolate, acute, and distinct, forming a nuchal “cape” of differently formed feathers. Third to fifth quill longest; first shorter than the seventh; outer five or six with their inner webs deeply emarginated.

This genus is almost peculiar to the Old World, where about seventeen so-called species are known, while America has no member of the genus exclusively its own, the single North American species being the same as the European one. Though the details of external structure vary somewhat, and the size ranges from that of a Buteo to that of a sea-eagle (Haliaëtus), the generic characters given in the above diagnosis apply well to all the species. The species of Heteropus, Hodgson, 1842 (A. malayensis, REIN. and H. gurneyi, Gray), I remove entirely from Aquila, since they differ so strikingly in many important respects. With the general aspect of Aquila, Heteropus has the outer toe disproportionately shorter than the inner (instead of equal to it, or longer), which curious feature it shares only with Geranospiza of tropical America, and Polyboroides of South Africa,—both terrestrial Buteonine forms of specialized structure. An entirely peculiar feature of Heteropus is the great length and straightness of the claws. Its bill is more like that of Archibuteo than like that of Aquila.

The North American and European races of the single species which occurs on the former continent may be distinguished as follows:—

Species and Races.

=A. chrysaëtus.= Wing, 23.00–27.00; tail, 14.00–16.00; culmen, 1.50–1.90; tarsus, 3.40–4.20; middle toe, 2.40–3.10. Third to fifth quill longest first shorter than seventh or eighth. Color blackish-brown, or umber-brown, nearly uniform, except on the tail; nuchal cape of lanceolate feathers, and tarsi of a paler and more tawny tint. Adult. Tail transversely clouded with ashy, and not white at the base; feathers of the body not distinctly white beneath the surface. Young. Tail with the basal half plain white, the terminal portion plain blackish; feathers of the body distinctly white beneath the surface. Hab. Nearctic and Palæarctic Realms.

Tarsi of adult pale umber; of young, dirty whitish. Hab. Palæarctic Realm …

var. chrysaëtus.

Tarsi of adult deep umber; of young light brown. Hab. Nearctic Realm …

var. canadensis.

Aquila chrysaëtus, var. canadensis (LINN.).

GOLDEN EAGLE; RING-TAILED EAGLE.

Aquila chrysaëtus (not of LINN.!), RICH. & SW. F. B. A. II, 1831, 12.—JARD. (WILS.) Am. Orn. II, 1832, 304.—BONAP. List, 1838, 2.—AUD. Synop. 1839, 9.—DE KAY, Zoöl. N. Y. II, 4, pl. vi, f. 14 (Juv.).—CASS. B. Cal. & Tex. 109.—STRICKL. Orn. Syn. I, 55 (in part).—BREWER, Oölogy, 1857, 45.—COUES, Key, 1872, 219. Falco chrysaëtus, (LINN.) MAX. Cab. J. 1858, VI, 9.—BLAS. Ber. XVI, Vers. Deutsch. Orn. 1862, 83 (“absolutely identical with European”). Falco canadensis, LINN. S. N. (ed. 10), 1766, 88. Aquila canadensis, WILS. Am. Orn. 1808, pl. lv, f. 1.—HEERM. P. R. R. Rept. II, 1855, 30.—CASS. Birds N. Am. 1858, 41.—COUES, P. A. N. S. 1866, 13.—GRAY, Hand List, I, 40. Falco niger, GMEL. S. N. 359. Aquila nobilis, PALL. Zoög. Ros. As. 1811. Aquila fulva (not of LINN.!), NUTT. Man. Orn. 1833, 62.—PEAB. B. Mass. 1841, 71.

SP. CHAR. Adult male (24,167, Fort Crook, North California, Dec. 25; D. F. Parkinson). General plumage fuliginous-black, this deepest on the head, throat, lower surface in general, under surface of the wings, back, scapulars, shoulders, secondaries, primaries, and rump; middle and secondary wing-coverts, upper and under tail-coverts, tarsi and inside of tibiæ, considerably paler, inclining to light umber. Lanceolate feathers of occiput and nape with the exposed portions light fulvous, the shafts black; dusky beneath the surface. Tail black, somewhat paler on basal half, and with about three irregular, obsolete zigzag bands of pale brown (on two middle feathers ashy); no concealed white on breast. Fifth quill longest; third and fourth intermediate between fifth and sixth; second considerably shorter than sixth; first intermediate between eighth and ninth. Length, 31.60; extent, 78.30. Wing, 24.50; tail, 13.40; culmen, 1.60; from base of cere, 2.15; tarsus, 3.85; middle toe, 2.40; hind claw (chord) 1.90.

Adult female (12,006, Washington, D. C., March 7, 1869; C. Drexler). Almost exactly like the male. Black covering forehead, ear-coverts, cheeks, chin, throat, foreneck, and under parts generally (except the tarsi, inside and front of tibiæ, and lower tail-coverts, which are light fulvous, the tarsi palest), more tawny than in the male. The lanceolate, pale, tawny feathers, which in the male cover only the occiput and neck, in the female extend forward over the top of the head, leaving the forehead only blackish. Upper parts and tail as in the male. Fourth quill longest; third slightly shorter than fifth; second intermediate between sixth and seventh; first intermediate between eighth and ninth. Wing, 26.00; tail, 14.25; culmen, 1.70; tarsus, 3.80; middle toe, 2.70; hind claw, 2.15; inner toe, 1.90; outer, 2.00; inner claw, 1.80; middle, 1.35; outer, 1.10.

Young male (49,684, Camp Grant, near Tucson, Arizona, July 10, 1867; Dr. E. Palmer). Continuous deep sepia-black, with a purplish lustre; breast and scapulars with large concealed spots of pure white; lanceolate feathers of the “mane” dull brown, not conspicuously different from the throat; under surface of primaries showing much white basally, this most extended on inner feathers. Upper and under tail-coverts more brownish than the rump, the basal portion white. Basal half or more of tail white (more ashy on outer feathers), distinctly defined against the broad, pure black, terminal zone; tarsi dull white, clouded with dilute brownish; inside of tibiæ with feathers tipped with white.

Young female (older?) (9,121, Washington, D. C., Dec., 1856; B. Cross). Similar, but black more brown; “mane” as in adult; tarsi dull whitish brown; tail-coverts deep umber-brown; tail as in young male, but terminal band narrower, the white occupying nearly the basal two thirds. Wing, 25.70; tail, 14.75; culmen, 1.65; middle toe, 2.80; hind claw, 2.20.

HAB. Whole of North America north of Mexico; most common in mountainous regions.

LIST OF SPECIMENS EXAMINED.

National Museum, 8; Philadelphia Academy, 2; Boston Society, 2; Cambridge Museum, 2; Coll. R. Ridgway, 2. Total, 16.

Measurements.

+----+-----------+-----------+---------+---------+-----------+----------+ |Sex.| Wing. | Tail. | Culmen. | Tarsus. |Middle Toe.|Specimens.| +----+-----------+-----------+---------+---------+-----------+----------+ | ♂ |23.00–24.50|14.00–15.00|1.50–1.62|3.65–3.80| 2.40–2.80| 5 | +----+-----------+-----------+---------+---------+-----------+----------+ | ♀ |25.00–27.00|15.00–16.00|1.68–1.85|4.15–4.20| 2.55–2.80| 7 | +----+-----------+-----------+---------+---------+-----------+----------+

A young male from Massachusetts (No. 39, Lexington; Dr. S. Kneeland), in the collection of the Boston Society of Natural History, has the tail plain black, the extreme base and tip white.

Though the Golden Eagles of North America can be distinguished by the characters given in the diagnosis on p. 312 from those of Europe, the differences are appreciable only on direct comparison. The American bird is darker in all its shades of color, the difference being most marked in the young plumage, which in var. chrysaëtus has the tarsal features nearly white, and in var. canadensis light brown, the brown of other portions being also considerably darker. The American bird appears to be rather the larger.

HABITS. The Ring-tailed or Golden Eagle of North America is found throughout the continent from the Atlantic to the Pacific, and from New Mexico to the higher Arctic regions.

In its geographical distribution, the Golden Eagle of North America appears to be chiefly confined to the mountainous regions, and the more northern portions, but to be nowhere abundant. Sir John Richardson saw but few individuals in the Arctic regions, nor does he appear ever to have met with its nest. Individual birds on the Atlantic coast have been occasionally obtained,—once as far south as Philadelphia, twice at Washington,—but very rarely. Several specimens appear to have been obtained among the mountains of New Mexico by Dr. Henry’s party.