Falcon, a bird of prey, belonging to the order raptores, family falconidoe, subfamily fal-coninm, and to the typical genus falco (Linn.). This subfamily contains the following genera, in addition to falco, of which about a dozen species are described: hypotriorchis (Boie), with as many species; ieracidea (Gould), with two species, found in Australia; tinnunculus (Vieill.), with a dozen species; ierax (Vigors), with six species, in India and its islands; and harpagus (Vigors), in South America, with a single species, characterized by having the lateral margin of the bill armed with two distinct teeth on each side. The birds of these genera may all be called falcons, from the common characters of a short bill, much curved from the base to the tip, with its sides more or less furnished with serrations called teeth; the cere covering the nostrils, which are rounded or linear; the wings lengthened and pointed, the second and third quills generally the longest; the tail lengthened and rounded; the toes long and slender, and claws curved and acute.

The birds of the genus falco, which only will be treated in this article, are called noble birds of prey, because in proportion to their size they are the most courageous and powerful; they are also more docile, and were formerly; much used in the sport of falconry to pursue and kill game, returning to their masters when called. The pigeon hawk (H. columharius), and the sparrow* hawk (T. sparverius), though both falcons, will be described under these names. The falcons are found throughout the world, regardless of climate; they are powerful and rapid fliers, hovering over their prey and darting perpendicularly upon it; they pursue birds chiefly, but attack also the smaller quadrupeds. The common or peregrine falcon (F. peregrinus, Linn.) has a large and round head, a short thin neck, a robust body broad in front, stout short tarsi, covered with imbricated scales largest in front, the tibial feathers covering the knee, long and strong toes and sharp claws. The plumage is compact and imbricated, the feathers rounded on the back, broad on the breast, long and pointed on the sides; between the eye and bill and on the forehead they are bristly. The bill is blackish blue at the tip and pale green at the base, the iris hazel, the feet bright yellow, and the claws black.

The head and hind neck in the adult male are grayish black tinged with blue, the rest of the upper parts dark bluish gray with indistinct dark brown bars; the quills dark brown, with transverse reddish white spots on the inner webs; the grayish brown tail has about 12 blackish bars, diminishing in breadth and intensity from the tip; the throat and front of neck white; a broad triangular mark of blackish blue extends downward on the white of the cheeks from the corner of the mouth; the sides, breast, and thighs are reddish white, with transverse dark brown spots; the under wing feathers are whitish, with transverse darker bars. The length is about 16 1/2 in., the extent of wings 30, bill 1 1/8, tarsus 1 1/2, and middle toe 2 1/2. In old males the tints of the back become lighter, sometimes ash-gray; the young males are darker, with rufous tips and edges to the feathers, and the tail is blacker, with reddish white tips and bars; there is considerable variety at the different ages in the birds of the United States and of Europe. Bonaparte calls the American bird F. anatum.

The adult female, as in birds of prey generally, is nearly one third larger than the male, being about 20 in. in length, 36 in extent of wings, with the beak, tarsus, and toes longer; the color of the upper parts is deeper brown, with the tips of the secondaries and tail whitish; the transverse markings run higher up on the breast, and are broader and of deeper hue on the other parts; the color below is more yellowish, and the vent feathers are reddish. This falcon, which is also called the great-footed and the duck hawk, according to Audubon, was formerly rare in the United States, which it now can hardly be said to be. It flies with astonishing rapidity, turning in its course in the most surprising manner. A favorite prey is the duck, which it seizes on the wing, on the surface of the water, or on land; when within a few feet of its victim, it stretches out the legs and claws and drops upon the trembling bird almost perpendicularly; if the victim is light, it flies off with it immediately to some quiet place; if too heavy, it kills and devours it in the nearest convenient place. It has been known to attack a mallard on the wing, and even to pounce upon a wounded teal within a few yards of the sportsman.

Pigeons, blackbirds, water fowl, and beach birds, and even dead fish, are eaten by this falcon. Turning the bird it has caught belly upward, it clears off the feathers from the breast and tears the flesh to pieces with great avidity. This species is solitary, except during the pairing of the breeding season, which is in very early spring; it is found in all parts of the United States and in Cuba, coming to the south in the winter months. The nest is made of coarse sticks, generally on the shelf of some precipitous rock; Audubon is of opinion that they breed in the United States; they are common on the shores of Hudson bay and arctic America in summer, according to Richardson; the eggs are rounded, reddish brown, with irregular markings of a darker tint. The peregrine falcon is distributed over temperate Europe, where the country is mountainous and the seacoast precipitous. When in full plumage and good condition, for its compact muscular form, great strength, boldness, and ferocity, it may be taken as the very type of a bird of prey; it is among birds what the lion and tiger are among mammals; fearless in attack, swift in pursuit, strong and fierce, it justly claims the first rank among the noble birds of prey.-Before the invention of gunpowder, falcons were very frequently trained to pursue herons and various kinds of game, and falconry was a favorite sport of kings and nobles; even now falcons are occasionally used for this purpose in Great Britain. Birds of prey have been trained to the chase from remote antiquity; the custom is mentioned by early writers, but it was not till the time of Huber, in 1784, that the distinction between birds of high and low flight, which had long been understood in practice, was shown to exist in the anatomical structure of the wings and talons.