FALCON, Falco, in the Linnmn zoology, a genus of birds, including all the diurnal birds of prey, now known as the family of falconiche; but in its present use as a generic name, limited to nearer accordance with its popular use, as a designation, of those spe cies which, in the language of falconry, were styled noble birds of true falcons are characterized by a bill curved from the base, the upper mandible hooked at the point, and the cutting edge of the upper mandible furnished with a strong projecting notch, or tooth. The claws are also sharp, curved, and strong; and in accordance with all this powerful armature, the whole frame is very robust and muscular. The legs are rather short, and have great power in striking or seizing prey. The keel of the sternum (breast bone) is very large, and adapted for the attachment of powerful muscles; the furcula and corticoid bones (see Bruns) are also very strong, so as to afford a sufficient resisting base for very powerful action of the wings. The wings are long and pointed, the first and third quill-feathers of equal length, the second rather the longest, the first anti second quill-feathers emarginated near the tip. The true falcons are bolder in proportion to their size than any other falconidae—even eagles. Their acuteness of vision is wonder ful; and they have very great powers of flight. A F. is known to have traversed the distance between Fontainebleau and Malta, not less than 1350 m., in 24 hours. The speed• attained by a F. iu pursuit of its prey has been calculated to be at the rate of 150 m. an hour. They soar to a prodigious height iu the air, always endeavoring to outsoar any bird of which they may be in pursuit, and to swoop down upon it from above; although it is far more difficult for them to rise vertically in a calm atmosphere than for birds of short and rounded wing, and they either rise obliquely—often also making their onward flight in a series of arcs—or avail themselves of the wind, and by flying against it, are borne aloft as a boy's kite is. The species are pretty numerous; some of them are of
very wide geographic distribution, whilst others are peculiar to certain countries or climates. The British species are the gyrfalcon (q.v.), or jerfalcon (F. gyrfalco), also known—although, perhaps, with difference of variety—as the Iceland F. and Greenland F.; the peregrine F. (q.v.) (F. peregrinus), of which the female is par excellence the F. of falconers (see FALCONRY), and the male is the tercel, tierce], or tercelet; the hobby (q.v.) (F. subbuteo); the red-footed F., or red-legged F. (F. rufipes), a small species, much resembling the hobby; the merlin (q.v.), (F. &salon); and the kestrel (q.v.), or windhover (F. tinnunculus). For the species chiefly used in falconry, see FALCONRY.
Very closely allied to the true falcons are the species constituting the genus hierax, very small, but remarkable for strength and courage, natives of the East Indies. The upper mandible has two notches. In the harpagow (harpagus or bidens) of South America, both mandibles have two notches. None of these, however, are equal to the true fal cons in length of wing.
For particulars regarding the falconidm, as subservient to field-sports, see FALCONRY.