FALCONI'DE, a family of diurnal birds of prey (see ACCIPITRES), corresponding with the Linnan genus faleo, and exhibiting those characters of muscular vigor, arma ture of beak and talons, and power of flight, which are to be found in their highest per fection in the true falcons (q.v.), and in a scarcely inferior degree in the eagles (q.v.). The species are numerous; the British museum alone contains specimens of almost 200 unquestionably distinct species; but very many supposed species have been named and described by ornithologists, which, in the progress of science, have been ascertained to owe their distinctive characters merely to age and sex. The female is generally larger than the male; and the plumage of the young different from that of the adult. There are, in the different groups, considerable diversities in the curvature and strength of the bill, which also has the cutting edges of the mandibles either notched, festooned, or plain ; the legs and toes also exhibit diversities as to length, strength, feathering, etc.; and in some groups, the wings are much longer, and at the same time more pointed, than in others. This is particularly the case with the true falcons, as contrasted with eagles, hawks, buzzards, kites, harriers, etc., and, in the language of falconry, the former—
having the second quill-feather longest, and the first nearly equal to it—are called noble birds of prey (see FALCONRY), being those usually domesticated and trained for the serv ice of man; the latter—having the fourth quill-feather longest, and the first very short —are called ignoble birds of prey, even eagles receiving this designation. The F. are dis tributed over all parts of the world; and almost all kinds of vertebrate animals, except the largest quadrupeds, are the prey of some of them. Some also devour insects. Like the felidce among ravenous quadrupeds, the F. do not willingly feed on carrion, but gen erally seize and kill their own prey. As in the felida, also, there is a provision for the preservation of the claws from being blunted by unnecessary contact with the ground, or with any hard substance, the F. contracting the toes so as to elevate their claws. The F. generally live in pairs.
The lg,mmergeier (q.v.) connects this family with the vultures; the secretary (q.v.), whilst in many respects agreeing with the F., is peculiar in some of its characters.