1. Morphnus unicinctus. (Temm.) Harris’ Buzzard. Falco unicinctus. Temm., Pl. col., I. p. (no page—livraison 53, about 1827.) “Falco anthracinus. Licht.” Gray, Genera, I. p. 27. Buteo Harrisii. Aud., Orn. Biog., V. p. 30. (1839.) Polyborus tæniurus. Tschudy, Wiegm. Archiv., X. p. 263. (1844.)
Temm., Pl. col., 313; Aud., B. of Am., pl. 392: oct. ed., I. pl. 5; Tschudy, Fauna Peruana Orn., pl. 1.
Legs long, and with the feet robust; wings rather short; tail long. Adult. Shoulders, wing-coverts and tibia chestnut-red or bay; other parts very dark umber-brown; upper and under tail-coverts white; tail white at its base, and tipped with white; middle portion presenting the appearance of a very wide band, dark brownish-black, with a reddish or violet tinge. Younger. Upper-parts umber-brown, much mixed with fulvous; shoulders chestnut-red, with dark-brown spots; quills dark-brown; secondaries tipped with yellowish-white; entire under-parts yellowish-white, many feathers on the breast, sides and abdomen, with large oblong and circular spots of brown; tibiæ yellowish-white, with transverse irregular lines of light brownish-red; upper and under tail-coverts white; tail brown, with many bands of a deeper shade of the same color, and with the inner-webs yellowish and reddish-white, and having many narrow bands of dark-brown; base and tip of the tail yellowish-white.
Dimensions. Female—total length, 22 to 24 inches; wing, 15; tail, 10 inches. Young male—total length, 20 inches; wing, 13; tail, 9½ inches.
Hab. Southern States; Mexico, abundant; Texas, frequent (Col. McCall); Mississippi, rare (Dr. Jenkins); Peru; Chili (Lieut. Gilliss); Chili, abundant (Gay, Fauna Chilena). Spec. in Mus. Acad., Philada.
Obs. Col. McCall, who has seen this bird in large numbers in Texas, represents it as habitually frequenting the ground in the vicinity of water, and especially abundant on both sides of the Rio Grande. It is slow and heavy in flight, and a dull, sluggish bird in all its habits, partaking in these respects of the general characters of the Vultures.
The affinities of this species we regard at present as uncertain, and arrange it provisionally only in the present genus and sub-family, but by no means agreeing in our views with late European ornithologists.
The foregoing are all the birds of this family which can be regarded as well-established species inhabiting that portion of North America, within our prescribed limits.
Respecting their history, one of the most important questions to the naturalist is, the change of plumage from young to mature age, and another change which takes place in assuming their spring or summer and their winter liveries. The latter change is by no means well understood in many species, and to ascertain it completely in any one would yet be an interesting contribution to its history.
A few species are known only as of exceedingly rare occurrence in the United States, but the larger number are sufficiently numerous to be investigated without difficulty. Of the former, the Washington Eagle (Haliaetus Washingtonii), Harlan’s Buzzard (Buteo Harlani), the Black Hawk, the Rough-legged Hawk (Archibuteo sancti-johannis and lagopus,) and nearly all the Western species, may be regarded as particularly requiring further research.
In the winter season, various species resort to the sea-coast, and others to the margins of bays and rivers in considerable numbers. In the vicinity of the cities these have, however, greatly diminished since the introduction of steamboats and railroads. Steam-engines, and especially locomotives, are innovations for which the Eagles and Hawks evidently have no fancy. To the markets appropriated to the accommodation of farmers and traders from the rural districts in all the cities on the Atlantic seaboard, specimens are frequently brought for sale, a demand, reliable to some extent, having arisen from collectors and amateurs.
Occasionally an immense multitude of Hawks soaring high in the air, and in company, has been observed. This curious phenomenon has been seen by our friends, Professor Baird, of the Smithsonian Institution, Washington city; Dr. Hoy, of Racine, Wisconsin; and by ourselves. It occurs in autumn, and is probably incidental to migration; but its exact character and object is unknown, and involves an interesting inquiry. It is necessarily temporary, as the procuring of suitable food by such a large number of rapacious birds would be impossible.
In the western and northern regions of North America, the birds of this family are particularly worthy of the attention of the traveller and naturalist, and would undoubtedly well repay him in the discovery of unknown species. This is the case also in the States of Florida and Texas, to the latter of which, very probably, some of the many Mexican species are visitors, that have not yet been noticed.