Pallas, a celebrated Russian naturalist, was the first who gave a satisfactory and reliable account of this Eagle, in his Zoology of Asiatic Russia, I. p. 343, (published at St. Petersburg in 1811, though printed many years previously,) but it appears to have been previously noticed by the distinguished navigators, Steller and Billings.
Before the time of Pallas, and, it may be added, since, also, various reports of remarkable and sometimes very large Eagles having been seen in different parts of America, were from time to time made by travellers and voyagers. In fact, some are carefully and credibly described which are yet unknown to naturalists. Capt. Cook, in the account of his last voyage, or rather in that part of it which was written by himself, states that several Eagles, one of which is very remarkable, were seen at Kayes’ Island, on the northwest coast of America, in latitude 59° 49′ N. “We saw,” he says, “flying about the woods, a Crow, two or three of the white-headed Eagles, mentioned at Nootka, and another sort full as large, which appeared also of the same colour, or blacker, and had only _a white breast_.” Last Voyage, II. p. 352, quarto, London, 1784. It is necessary for me to say only, that no species of Eagle having a white breast is yet known as an inhabitant of any part of America.
In the History of the Expedition of Lewis and Clarke it is stated, that “The Calumet Eagle sometimes inhabits this side of the Rocky mountains. The colours are black and white, beautifully variegated. The tail feathers, so highly prized by the natives, are composed of twelve broad feathers of unequal length, which are white except within two inches of their extremities, when they immediately change to a jetty black, the _wings_ have each a large circular _white spot_ in the middle, which is only visible when they are extended.” II. p. 188, Philada., 1814. This statement, though it appears to have been usually regarded as referring to the Golden Eagle, does not apply to any established species, but it is worth bearing in mind that in the number of the feathers of the tail, the bird here alluded to agrees exactly with Audubon’s Washington Eagle, (Orn. Biog. I. p. 63.)
The black-checked Eagle of Pennant, said to be from North America, (Arctic Zoology, I. p. 227,) and which is _Falco americanus_, Gmelin, is described as being “about the size of the Golden Eagle, but with the head, neck and breast of a _deep ash colour_, each cheek marked with a broad black bar, passing from the corner of the mouth beyond the ears; back, belly, wings and tail, black.”