Falco

Falco is a genus of falconiform birds of the family Falconidae; several species are commonly known as hawks, kestrels, or alcotanes.

Hawks have thin, pointed wings that allow them to reach extremely high speeds. Peregrine falcons are the fastest animals on the planet, reaching speeds in swooping flight between 230 and 360 km/h. In horizontal flight they reach 96 km/h.

Summary

Hawks are roughly divided into three or four groups. The first contains kestrels (probably excepting the American kestrel); they are usually small, stout hawks whose backs are mainly brown and sometimes sexually dimorphic; three African species that are generally gray in color are distinguishable from typical members of this group. Kestrels feed primarily on suitable-sized vertebrate and invertebrate land animals such as rodents, reptiles, or insects.

The second group contains slightly larger species (on average), the hawk and its relatives. These birds are characterized by a considerable amount of dark slate gray in their plumage; their malar areas are almost always black. They mainly feed on smaller birds.

Third are the peregrine falcon and its relatives, powerful birds of variable size that also have a black malar area (except some very light-colored morphs), and often a black cap as well. They are very fast birds, with a maximum speed of 390 kilometers per hour. They are otherwise somewhat intermediate between the other groups, being mainly gray in color with some lighter shades or brown on their upperparts. On average, they are more delicately patterned than aficionados and, excluding hooters and hierophalids (see below), this group usually contains species with horizontal barring on the underside. Unlike the other groups, where tail color varies greatly overall but little by evolutionary relatedness, the fox kestrel and greater kestrel, however, can be differentiated at first glance by tail color, but not for much longer; they could be very close relatives and are probably much closer to each other than the lesser and common kestrels. The tails of large falcons are a fairly uniform dark grey, with an inconspicuous black band and small white tips, although this is probably plesiomorphic. These large species of Falco feed on medium-sized birds and terrestrial vertebrates.

Very similar to, and sometimes included in, these are the roughly four species of hierofalcon (lit. "falcon-falcon"). They represent taxa with generally more pheomelanins, imparting reddish or brown colors, and generally more heavily patterned plumage reminiscent of falcons. Their underparts have a longitudinal pattern of arrowhead-shaped spots, lines, or markings.

Although these three or four loosely circumscribed groups are an informal arrangement, they probably contain several distinct clades in their entirety.

A study of the mtDNA cytochrome b sequence of some kestrels identified a clade containing the common kestrel and related species with a malar stripe, excluding taxa such as the greater kestrel (which lacks a malar stripe), the lesser kestrel (which lacks is very similar to the common one, but also lacks a malar stripe), and the American kestrel, which has a malar stripe, but its color pattern - apart from the brownish back - and also the black feathers behind the ear, which never occur in the true kestrels, are more reminiscent of some hobbies. Malar kestrels apparently diverged from their relatives in the Gelasian, about 2.0-2.5 million years ago (Mya), and are apparently of tropical east African origin. The entire group of "true kestrels" -excluding the American species- is probably a distinct and fairly young clade, as also suggested by its numerous apomorphies.

Most gender members Falco show a "dient" in the upper jaw

Other studies have confirmed that hierophilic falcons are a monophyletic group and that hybridization is quite common at least in the larger falcon species. Initial studies of mtDNA cytochrome b sequence data suggested that hieroglyphic hawks are basal among living hawks. The discovery of a NUMT proved this earlier theory wrong. Actually, hieroglyphic falcons are a fairly young group, originating at the same time as the start of the main kestrel radiation, around 2 Mya. There is very little fossil history of this lineage. However, the current diversity of very recent origin suggests that this lineage may have been on the brink of extinction in the recent past.

The phylogeny and group boundaries of peregrines and gannets are more problematic. Molecular studies have only been carried out on a few species, and morphologically ambiguous taxa have often been poorly investigated. The morphology of the syrinx, which contributes well to resolving the general phylogeny of the Falconidae, is not very informative in the present genus. However, it is confirmed that a core group containing Peregrine and Barbary falcons, which, in turn, are grouped with Hierofalcons and the farthest prairie falcon (sometimes placed with Hierofalcons, although is totally distinct biogeographically), as well as at least most 'typical' hobbies, are monophyletic as suspected.

Since present-day American Falco species belong to the peregrine group, or are apparently more basal species, the initially most successful evolutionary radiation appears to have been a Holarctic originating possibly around central Eurasia or in (northern) Africa. One or more lineages were present in North America no later than the early Pliocene.

The origin of the main current Falco groups -the "típicos" gannets and kestrels, for example, or the peregrine-hierophallic falcon complex, or the lineage of the aplombado falcon - can be placed quite safely from the Miocene-Pliocene boundary through the Zanclean and Piacenzian and right into the Gelasian, that is, between 2. 4 to 5.3 Mya, when malar kestrels diversified. Some groups of falcons, such as the hierofalcon complex and the peregrina-barbara superspecies, have only evolved in more recent times; species of the former appear to be about 120,000 years old.

Species

American Cernícalo (American Cerní)Falco sparverius cinnamominus) in Montevideo, Uruguay.

Halcon aletoFalco femoralis).

American Cernícalo (American Cerní)Falco sparverius cinnamominus) in Montevideo, Uruguay.