1. Hierofalco sacer. (Forster.) The American Gyr Falcon. Falco sacer. Forster, Phil. Trans. London, LXII. p. 423. (1772.) Falco fusca. Fabricius Fauna Grœnlandica, p. 56, (1780,) not Gmelin, (1788.) Falco cinereus. Gmelin, Syst. Nat. I. p. 267. (1788.) Falco grœnlandicus. Turton, Syst. Nat. I. p. 147. (1806.) Falco labradora. Audubon, B. of Am. p. 196, (name on plate pub. about 1834.) “Falco candicans. Gmelin.” Bonap. Cons. Av. p. 23. “Falco grœnlandicus. Turton,” Hancock in Ann. and Mag., Nat. Hist. II. p. 249. “Falco islandicus. Lath.” Aud. Orn. Biog. II. p. 552.
Edwards’ Birds, II. pl. 53, young. Aud. B. of Am. pl. 196, young, (but not pl. 366 which represents another species.) Schlegel, Traité de Fauconnerie, pl. (no number,) adult. Ann. & Mag. Nat. Hist. II. pl. 10, (feathers.)
Form strong, and robust; second and third quills (in the young bird) longest and nearly equal. Adult, according to Hancock as cited above, “ground of the plumage pure white, upper parts elegantly marked with arrow shaped spots of a dark gray; under parts and head streaked with the same; wings reaching to within two inches of the end of the tail; second primary the longest.”
Young. Entire plumage, brown, tinged with cinereous on the upper parts. Throat, dull white; all the plumage of the under parts edged with and having circular spots of dull yellowish white, the rounded spots more apparent on the tibia and under tail-coverts. Quills, mottled with the same white on their inner webs; tail, with numerous (about thirteen) irregular bars of the same. “Bill and cere, pale blue; iris, brownish black. Feet, grayish blue; the under parts of the toes greenish yellow; claws dusky.” (Audubon.)
Hab. Northern America. Greenland, (Fabricius, Hancock,) Hudson’s Bay, (Richardson,) Labrador, (Audubon,) Louisville, Kentucky, (Mr. C. W. Webber.) Spec. in Mus. Nat. Hist. Soc. Charleston, S. C.
Obs. The Gyrfalcon is of very rare occurrence in the United States, though not unfrequent in the northern regions of this continent.
Mr. Hancock, whose opportunities were ample, fully demonstrates (as cited above) that the Falco grœnlandicus of Greenland, which is the present species, and the Falco islandicus of Iceland, are distinct, which appears to be assented to by all late writers. The bird, figured by Mr. Audubon as the adult of the species of which the young bird was obtained by him in Labrador, was an Iceland specimen, (Orn. Biog. IV. p. 476,) and therefore not correctly given as the American bird. We have never had the satisfaction of seeing the adult of this species; but for an opportunity of examining one of Mr. Audubon’s Labrador specimens, we are indebted to the Rev. John Bachman, D. D., of Charleston, S. C., who, with that disposition to advance the interests of Zoological Science which has always characterized him, most kindly forwarded it at our request.
Turton’s description above cited, is copied by him from Pennant’s Greenland Falcon, Arctic Zoology, I. p. 257.
III. GENUS HYPOTRIORCHIS. Boie Isis, p. 976. (1826.)
DENDROFALCO. Gray list, p. 3. (1840.)
Size small, tarsus lengthened and rather slender. In all other characters much like typical Falco. Toes long, slender and furnished with sharp, curved claws. This genus includes about ten or twelve small species found in various parts of the world, and for the greater part dark colored, like the species of typical Falco.
1. Hypotriorchis columbarius. (Linn.) The Pigeon Hawk. Falco columbarius. Linn. Syst. Nat. I. p. 128. (1766.) Falco intermixtus. Daudin, Traité d’Orn. II. p. 141. (1800.) Falco temerarius. Aud. B. of Am. I. p. 381. (1831, plate pub. 1829) “Falco æsalon. Temm.” Rich. and Sw. Faun. Bor. Am. Birds, p. 37.