The
genus Falco was introduced in 1758 by the Swedish naturalist
Carl Linnaeus in the
tenth edition of his
Systema Naturae. The
type species is the
merlin (
Falco columbarius). The genus name is
Late Latin meaning a "falcon" from , , meaning "a sickle", referring to the claws of the bird. In
Middle English and
Old French, the title refers generically to several captive raptor species. (). A falcon chick, especially one reared for
falconry, still in its downy stage, is known as an
eyas (sometimes spelled
eyass). The word arose by mistaken division of
Old French , from Latin presumed (nestling) from (
nest). The technique of hunting with trained captive birds of prey is known as
falconry. Compared to other birds of prey, the
fossil record of the falcons is not well distributed in time. For years, the oldest fossils tentatively assigned to this genus were from the Late
Miocene, less than 10 million years ago. This coincides with a period in which many modern genera of birds became recognizable in the fossil record. As of 2021, the oldest falconid fossil is estimated to be 55 million years old. Given the distribution of fossil and living
Falco taxa, falcons are probably of North American, African, or possibly Middle Eastern or European origin. Falcons are not closely related to other birds of prey, and their
nearest relatives are
parrots and
songbirds.
Overview Falcons are roughly divisible into three or four groups. The first contains the
kestrels (probably excepting the
American kestrel); the tails of the large falcons are quite uniformly dark grey with inconspicuous black banding and small, white tips, though this is probably
plesiomorphic. These large
Falco species feed on mid-sized birds and terrestrial vertebrates. Very similar to these, and sometimes included therein, are the four or so species of
hierofalcon (literally, "hawk-falcons"). They represent taxa with, usually, more
phaeomelanins, which impart reddish or brown colors, and generally more strongly patterned plumage reminiscent of
hawks. Their undersides have a lengthwise pattern of blotches, lines, or arrowhead marks. While these three or four groups, loosely circumscribed, are an informal arrangement, they probably contain several distinct
clades in their entirety. A study of
mtDNA cytochrome b sequence data of some kestrels •
Falco sp. (Early •
Falco oregonus (Early/Middle Pliocene of Fossil Lake, Oregon) – possibly not distinct from a living species •
Falco umanskajae (Late Pliocene of Kryzhanovka, Ukraine) – includes "
Falco odessanus", a
nomen nudum •
Falco antiquus (Middle Pleistocene of Noailles, France and possibly Horvőlgy, Hungary) Several more paleosubspecies of extant species have also been described; see species accounts for these.
"Sushkinia" pliocaena from the Early Pliocene of Pavlodar (Kazakhstan) appears to be a falcon of some sort. It might belong in this genus or a closely related one. The supposed
"Falco" pisanus was actually a pigeon of the genus
Columba, possibly the same as
Columba omnisanctorum, which, in that case, would adopt the older species name of the "falcon". The
Eocene fossil
"Falco" falconellus (or
"F." falconella) from Wyoming is a bird of uncertain affiliations, maybe a falconid, maybe not; it certainly does not belong in this genus.
"Falco" readei is now considered a
paleosubspecies of the
yellow-headed caracara (
Daptrius chimachima). ==See also==