Falcon
Brown Falcon ()
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Falconiformes
Family:	Falconidae
Subfamily:	Falconinae
Genus:	Linnaeus, 1758
Species
About 37; see text.
Synonyms
Linnaeus, 1766 Cuvier, 1817 Boie, 1826 Boie, 1826 Nitzsch, 1829 Gould, 1838 Strickland, 1841 (unjustified emendation)[] Kaup, 1847 Kaup, 1850 (unjustified emendation) Bonaparte, 1855 ( Lacepède 1802[]: preoccupied) Sclater, 1864 Heuglin, 1867 (unjustified emendation)[] Sharpe, 1874 ( Pallas 1774: preoccupied) Heine & Reichenow, 1890[] (unjustified emendation)[] Oberholser, 1899 Dubois, 1902 (unjustified emendation) De Vis, 1906 (non Brehm 1855: preoccupied) Richmond, 1908 Tugarinov, 1935 ( Martynov 1930: preoccupied) - see below

A falcon ( /ˈfɔːlkən/ or /ˈfælkən/) is any species of raptor in the genus . The genus contains 37 species, widely distributed throughout Europe, Asia, and North America.

Adult falcons have thin tapered wings, which enable them to fly at high speed and to change direction rapidly. Fledgling falcons, in their first year of flying, have longer flight feathers which makes their configuration more like that of a general-purpose bird such as a broadwing. This makes it easier to fly while learning the exceptional skills required to be effective hunters as adults.

Peregrine Falcons have been recorded diving at speeds of 200 miles per hour (320 km/h), making them the fastest-moving creatures on Earth. Other falcons include the Gyrfalcon, Lanner Falcon, and the Merlin. Some small falcons with long narrow wings are called hobbies, and some which hover while hunting are called kestrels. The falcons are part of the family Falconidae, which also includes the caracaras, Laughing Falcon, forest falcons, and falconets.

The traditional term for a male falcon is (British spelling) or (American spelling), from Latin = third because of the belief that only one in three eggs hatched a male bird. Some sources give the etymology as deriving from the fact that a male falcon is approximately one third smaller than the female (Old French ).

A falcon chick, especially one reared for falconry, that is still in its downy stage is known as an (sometimes spelt ). 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.

As is the case with many birds of prey, falcons have exceptional powers of vision; the visual acuity of one species has been measured at 2.6 times that of a normal human.

In February 2005, the Canadian ornithologist Louis Lefebvre announced a method of measuring avian intelligence in terms of a bird's innovation in feeding habits. The falcon and corvids scored highest on this scale.

Systematics and evolution

Compared to other birds of prey, the fossil record of the falcons is not well distributed in time. The oldest fossils tentatively assigned to this genus are 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. The falcon lineage may however be somewhat older than this and given the distribution of fossil and living taxa is probably of North American, African or possibly Middle Eastern or European in origin.

Overview

Falcons are roughly divisible into three or four groups. The first contains the kestrels (probably excepting the American Kestrel); usually small and stocky falcons of mainly brown upperside color and sometimes sexually dimorphic; three African species that are generally grey in colour stand apart from the typical members of this group. Kestrels feed chiefly on terrestrial vertebrates and invertebrates of appropriate size, such as rodents, reptiles, or insects.

The second group contains slightly larger (on average) and more elegant species, the hobbies and relatives. These birds are characterized by considerable amounts of dark slate-grey in their plumage; the malar area is nearly always black. They feed mainly on smaller birds.

Third are the Peregrine Falcon and its relatives: large powerful birds which also have a black malar area (except some very light color morphs), and often a black cap also. Otherwise, they are somewhat intermediate between the other groups, being chiefly medium grey with some lighter or brownish colours on the upper side. They are on average more delicately patterned than the hobbies and if the hierofalcons are excluded (see below), this group contains typically species with horizontal barring on the underside. As opposed to the other groups, where tail colour varies much in general but little according to evolutionary relatedness, the tails of the large falcons are quite uniformly dark grey with rather inconspicuous black banding and small white tips, though this is probably plesiomorphic. These large feed on mid-sized birds and terrestrial vertebrates.

Very similar to these and sometimes included therein are the 4 or so species of hierofalcons (literally, "hawk-falcons"). They represent taxa with usually more phaeomelanins which impart reddish or brown colours, and generally more strongly patterned plumage reminiscent of hawks. Notably, 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 sequence data of some kestrels (Groombridge 2002) identified a clade containing the Common Kestrel and related "malar-striped"^[] species, to the exclusion of such taxa as the Greater Kestrel (which lacks a malar stripe), the Lesser Kestrel (which is very similar to the Common but also has no malar stripe), and the American Kestrel. The latter species has a malar stripe, but its color pattern–apart from the brownish back–and notably also the black feathers behind the ear, which never occur in the true kestrels, are more reminiscent of some hobbies. The malar-striped kestrels apparently split from their relatives in the Gelasian, roughly 2.5-2 mya, and are apparently of tropical East African origin. The entire "true kestrel" group—excluding the American species—is probably a distinct and quite young clade, as also suggested by their numerous apomorphies.

Most members of the genus show a on the upper mandible

Other studies have confirmed that the hierofalcons are a monophyletic group–and, incidentally, that hybridization is quite frequent at least in the larger falcon species. Initial studies of mtDNA cytochrome sequence data suggested that the hierofalcons are basal among living falcons. This is now known to be an erroneous result due to the presence of a numt (Wink & Sauer-Gürth 2000); in reality the hierofalcons are a rather young group, originating maybe at the same time as the start of the main kestrel radiation, about 2 million years ago. This lineage seems to have gone nearly extinct at some point in the past; the present diversity is of very recent origin, though little is known about their fossil history (Nittinger 2005, Johnson 2007).

The phylogeny and delimitations of the Peregrine and hobbies groups is more problematic. Molecular studies have only been conducted on a few species, and namely the morphologically ambiguous taxa have often been little researched. The morphology of the syrinx, which contributes well to resolving the overall phylogeny of the Falconidae, is not very informative in the present genus. Nonetheless, a core group containing the Peregrine and Barbary falcons which in turn group with the hierofalcons and the more distant Prairie Falcon (which was sometimes placed with the hierofalcons, even though it is entirely distinct biogeographically), as well as at least most of the "typical" hobbies, are confirmed to be monophyletic as suspected.

Given that the American s of today belong to the Peregrine group or are apparently more basal species, it seems that the initially most successful evolutionary radiation was an Holarctic one that originated possibly around central Eurasia or in (northern) Africa. One or several lineages were present in North America by the Early Pliocene at latest.

The origin of today's major groups—the "typical" hobbies and kestrels for example, or the Peregine-hierofalcon complex, or the Aplomado Falcon lineage—can be quite confidently placed from the Miocene-Pliocene boundary through the Zanclean and Piacenzian and just into the Gelasian, that is from about 8 to 2.4 million years ago, when the malar-striped kestrels diversified. Some groups of falcons, such as the hierofalcon complex or the Peregrine-Barbary superspecies have only evolved in more recent times; the species of the former seem to be a mere 120,000 years old or so (Nittinger 2005).

Species

Common Kestrel

New Zealand Falcon

Saker Falcon, a typical hierofalcon

The sequence follows the taxonomic order of White (1996), except for adjustments in the kestrel sequence.

• Madagascar Kestrel,
• Seychelles Kestrel,
• Mauritius Kestrel,
• Réunion Kestrel, - extinct (c.1700)
• Spotted Kestrel,
• Nankeen Kestrel or Australian Kestrel,
• Common Kestrel,
  • Rock Kestrel,
• Greater Kestrel,
• Fox Kestrel,
• Lesser Kestrel,
• Grey Kestrel,
• Dickinson's Kestrel,
• Banded Kestrel,
• Red-necked Falcon,
  • African Red-necked Falcon,
• Red-footed Falcon,
• Amur Falcon,
• Eleonora's Falcon,
• Sooty Falcon,
• American Kestrel or "Sparrow Hawk",
• Aplomado Falcon,
• Merlin or "Pigeon Hawk",
  • Eurasian Merlin,
• Bat Falcon,
• Orange-breasted Falcon,
• Eurasian Hobby,
• African Hobby,
• Oriental Hobby,
• Australian Hobby or Little Falcon,
• New Zealand Falcon,
• Brown Falcon,
• Grey Falcon,
• Black Falcon,
• Lanner Falcon,
• Laggar Falcon,
• Saker Falcon,
  • Altai Falcon, (status unclear)
• Gyrfalcon,
• Prairie Falcon,
• Peregrine Falcon,
  • Peale's Falcon,
  • Pallid Falcon, var.
  • Barbary Falcon,
• Taita Falcon,

Fossil record

• (Late Miocene of Cherevichnyi, Ukraine)
• sp. (Late Miocene of Idaho)
• sp. (Early Pliocene of Kansas)
• sp. (Early Pliocene of Bulgaria - Early Pleistocene of Spain and Czechia)
• (Early/Middle Pliocene of Fossil Lake, Oregon) - possibly not distinct from a living species
• (Late Pliocene of Kryzhanovka, Ukraine) - includes "Falco odessanus", a
• (Late Pliocene of Varshets, Bulgaria)
• (Middle Pleistocene of Noailles, France and possibly Horvőlgy, Hungary)
• Cuban Kestrel, (Late Pleistocene/Holocene of Cuba, West Indies)
• (China)

Several more paleosubspecies of extant species also been described; see species accounts for these.

from the Early Pliocene of Pavlodar (Kazakhstan) appears to be a falcon of some sort. It might belong into this genus or a closely related one (Becker 1987). In any case, the genus name is invalid for this animal because it had already been allocated to a prehistoric dragonfly relative.

The supposed was actually a pigeon of the genus , possibly the same as which in that case would adopt the older species name of the "falcon" (Mlíkovský 2002). The Eocene fossil (or ) from Wyoming is a bird of uncertain affiliations, maybe a falconid, maybe not; it certainly does not belong into this genus. is now considered a paleosubspecies of the Yellow-headed Caracara ().

• Becker, Jonathan J. (1987): Revision of Wetmore and the Neogene evolution of the Falconidae. 104(2): 270-276. PDF fulltext
• Feduccia, J. Alan (1970): Some birds of prey from the Upper Pliocene of Kansas. 87(4): 795-797. PDF fulltext
• Griffiths, Carole S. (1999): Phylogeny of the Falconidae inferred from molecular and morphological data. 116(1): 116–130. PDF fulltext
• Griffiths, Carole S.; Barrowclough, George F.; Groth, Jeff G. & Mertz, Lisa (2004): Phylogeny of the Falconidae (Aves): a comparison of the efficacy of morphological, mitochondrial, and nuclear data. 32(1): 101–109. doi:10.1016/j.ympev.2003.11.019 (HTML abstract)
• Groombridge, Jim J.; Jones, Carl G.; Bayes, Michelle K.; van Zyl, Anthony J.; Carrillo, José; Nichols, Richard A. & Bruford, Michael W. (2002): A molecular phylogeny of African kestrels with reference to divergence across the Indian Ocean. 25(2): 267–277. doi:10.1016/S1055-7903(02)00254-3 (HTML abstract)
• Helbig, A.J.; Seibold, I.; Bednarek, W.; Brüning, H.; Gaucher, P.; Ristow, D.; Scharlau, W.; Schmidl, D. & Wink, Michael (1994): Phylogenetic relationships among falcon species (genus Falco) according to DNA sequence variation of the cytochrome b gene. Meyburg, B.-U. & Chancellor, R.D. (eds.): : 593-599. PDF fulltext
• Johnson, J.A.; Burnham, K.K.; Burnham, W.A.; Mindell, D.P. (2007): Genetic structure among continental and island populations of gyrfalcons. 16:3145-3160. doi:10.1111/j.1365-294X.2007.03373.x (HTML abstract)
• Martin, R.A.; Honey, J.G. & Pelaez-Campomanes, P. (2000): The Meade Basin Rodent Project; a progress report. Kansas Geologial Survey Open-file Report 2000-61^[]. 3(1): 1-32.
• Mlíkovský, Jirí (2002): . Ninox Press, Prague. ISBN 80-901105-3-8 PDF fulltext
• Nittinger, F.; Haring, E.; Pinsker, W.; Wink, Michael & Gamauf, A. (2005): Out of Africa? Phylogenetic relationships between and other hierofalcons (Aves Falconidae). 43(4): 321-331. doi:10.1111/j.1439-0469.2005.00326.x PDF fulltext
• Sobolev, D.V. (2003): Новый вид плиоценового сокола (Falconiformes, Falconidae) [A new species of Pliocene falcon (Falconiformes, Falconidae)] 37 (6): 85–87. [Russian with English abstract] PDF fulltext
• White, Clayton M.; Olsen, Penny D. & Kiff, Lloyd F. (1994): Family Falconidae. del Hoyo, Josep; Elliott, Andrew & Sargatal, Jordi (editors): : 216-275, plates 24-28. Lynx Edicions, Barcelona. ISBN 84-87334-15-6
• Wink, Michael & Sauer-Gürth, Hedi (2000): Advances in the molecular systematics of African raptors. Chancellor, R.D. & Meyburg, B.-U. (eds): : 135-147. WWGBP/Hancock House, Berlin/Blaine. PDF fulltext
• Wink, Michael; Seibold, I.; Lotfikhah, F. & Bednarek, W. (1998): Molecular systematics of holarctic raptors (Order Falconiformes). Chancellor, R.D., Meyburg, B.-U. & Ferrero, J.J. (eds.): : 29-48. Adenex & WWGBP. PDF fulltext
• Wink, Michael; Sauer-Gürth, Hedi; Ellis, David & Kenward, Robert (2004): Phylogenetic relationships in the Hierofalco complex (Saker-, Gyr-, Lanner-, Laggar Falcon). Chancellor, R.D. & Meyburg, B.-U. (eds.): : 499-504. WWGBP, Berlin. PDF fulltext