Embracing about fifty species, inhabiting all parts of the earth, and may be regarded as presenting the highest organization of the Rapacious form of Birds.
A.
I. Genus Falco. Linnæus Syst. Nat., I. p. 124. (1766.)
General form, robust and powerful; bill, short, with the upper mandible curved, and with a distinct tooth; nostrils, circular, with a central tubercle. Wings, long, pointed, formed for vigorous and rapid flight; tail, rather long; tarsi, short, robust, covered with rounded or hexagonal scales; middle toe long, claws large, curved, and very sharp. This genus, as restricted, contains from fifteen to twenty species, found in various parts of the world, several of which more or less intimately resemble the Falco peregrinus of Europe, and the Falco anatum of America. They are remarkable for exceedingly rapid flight, and great boldness in attacking animals on which they prey.
1. Falco anatum. Bonap. Comp. List p. 4. (1838.) “Falco peregrinus Gm.” Wilson, Audubon and other authors.
Edwards’ Birds, I. pl. 3, 4. Wilson Am. Orn. IX. pl. 76. Aud. B. of Am. pl. 16, octavo edition, I. pl. 20. De Kay, Nat. Hist. State of New York Birds, pl. 3. fig. 8. Lembeye B. of Cuba, pl. 1. fig. 2.
Bill, rather short, strong, very sharp, with a well defined tooth in the upper mandible; wings long, legs strong, middle toe long, claws curved, sharp.
Adult. Frontal band white; top of the head, back, wing-coverts and rump, bluish cinereous; every feather crossed transversely with bands of brownish black; rump and lower part of the back lighter, and with the dark bands less numerous.
Throat, sides of the neck and upper part of the breast white, with a tinge of buff without spots, other under parts same color, with a deeper shade, and with cordate or rounded spots of black on the lower breast and abdomen, and transverse bars of the same black on the sides, under tail-coverts and tibiæ. Quills, brownish black, with transverse bars of yellowish white on their inner webs. Tail, brownish black, with transverse bars of cinereous, very pale and nearly white on their inner webs, and narrowly tipped with white.
Cheeks with a patch of black most narrow and clearly defined in the adult bird, and separated from the color of the back of the head by a white space; back of the neck, mixed with yellowish feathers, forming an irregular collar. Bill, light bluish horn color, paler at the base; legs and feet fine yellow. Sexes alike.
Younger. Entire plumage above, brownish black; nearly uniform on all parts, and with little or no appearance of the bars which are seen in the adult. Tail, uniform dark brown, with spots or irregular transverse stripes of reddish white frequently only on the inner webs. Frontal spot of white obscure, large space on the cheek, black not separated posteriorly from the same color of the head above. Under parts, white and yellowish white, every feather, except on the throat, with a wide longitudinal stripe of dark brown; the latter color prevailing on the sides and abdomen. Throat, white, nearly every feather with a very narrow central line of black. Tarsi and feet, bluish lead color.
Dimensions. Female, total length 19 to 20 inches; wing, 14½ to 15; tail, 7½ to 8 inches. Male and young smaller.
Hab. The entire eastern portion of North America, and perhaps western; Greenland? Oregon? (U. S. Ex. Exp.) Jamaica, (Mr. Gosse.) Cuba, (Mr. Lembeye.) Bermuda, (Sir W. Jardine.) Spec. in Mus. Acad. Philada.
Obs. In the adult of this species, there is a white frontal band as in the adult of the European F. peregrinus.
It is very similar in color and general characters to that species, but is larger, and the young differ.
Audubon’s figures represent the dark-colored plumage described above as that of young or immature birds. Wilson’s figure is that of a more adult specimen, with the frontal band partially produced; but the bird in completely mature plumage, has never been figured.