Peregrine Falcon (Falco peregrinus)
Falconidae or falcons and caracaras, is a family of diurnal birds of prey. The family is divided into two subfamiles, Polyborinae, which includes the caracaras and forest falcons, and Falconinae, the falcons, kestrels and falconets. They differ from the eagles of Accipitridae, in that falcons kill with their beaks instead of their taloned feet. They have a "tooth" on the side of their beak for the purpose.
Falcons and caracaras are small to medium-sized birds of prey, ranging in size from the black-thighed falconet, which can weight as little as 35 grams (1.2 oz), to the gyrfalcon, which can weigh as much as 1,735 grams (61.2 oz). They have strongly hooked bills, sharply curved talons and excellent eyesight. The plumage is usually composed of browns, whites, chestnut, black and grey, often with barring of patterning. There is little difference in the plumage of males and females, although a few species have some sexual dimorphism in boldness of plumage.
Taxonomy and SystematicsEdit
Traditionally, the raptors were grouped into four families in the single order Falconiformes, but many thought this group to be paraphyletic and not to share a common ancestor to the exclusion of all other birds.
First, multiple lines of evidence in the 1970s and 1980s suggested that the New World vultures Cathartidae were closer related to storks and herons (Ciconiiformes), though more recent place them outside that group as well. Consequently, New World vultures are now often raised to the rank of an independent order Cathartiformes not closely associated with either birds of prey or storks or herons. In 2007, the American Ornithologists' Union's North American checklist moved Cathartidae back into the lead position in Falconiformes, but with an asterisk that indicates it is a taxon "that is probably misplaced in the current phylogenetic listing but for which data indicating proper placement are not yet available".
In Europe, it has become common to split the remaining raptors into two: the falcons and caracaras remain in the order Falconiformes (about 60 species in 4 groups), and the remaining 220-odd species (including the Accipitridae – eagles, hawks, Old World vultures, etc.) are put in the separate order Accipitriformes. An unplaced prehistoric family known only from fossils are the Horusornithidae.
In agreement with the split of Falconiformes and Accipitriformes, comparative genome analysis published in 2008 suggested that falcons are more closely related to the parrots and passerines than to other birds including the Accipitridae, so that the traditional Falconiformes are paraphyletic even if the Cathartidae are excluded. Indeed, a 2011 analysis of transposable element insertions shared between the genomes of falcons, passerines, and parrots, but not present in the genomes of other birds, confirmed that falcons are a sister group of the combined parrot/passerine group, together forming the clade Eufalconimorphae.
The clade Falconidae is compound by the groups Polyborinae and Falconinae. The first contains the caracaras, forest falcons, and laughing falcon. All species in this group are native to the Americas. The composition of Falconidae is disputed, and Polyborninae is not featured in the American Ornithologists' Union checklists for North and South American birds. The Check-list of North American Birds considers the laughing falcon a true falcon (Falconinae) and replaces Polyborinae with Caracarinae and Micrasturinae. On the other hand, the Check-list of South American Birds classifies all caracaras as true falcons and puts the laughing falcon and forest falcons into the subfamily Herpetotherinae.
On the other hand, Falconinae, in its traditional classification, contains the falcons, falconets, and pygmy falcons. Depending on the authority, Falconinae may also include the caracaras and/or the laughing falcon.
Subfamily: Polyborinae Genus: Daptrius (Monotypic) Genus: Ibycter (Monotypic) (sometimes included in Daptrius) Genus: Phalcoboenus (4 species) Genus: Caracara (2 living species, 1 extinct) Genus: Milvago (2 species) Genus: Micrastur (Forest Falcons) (7 species) Subfamily: Falconinae Genus: Herpetotheres (Monotypic) Genus: Spiziapteryx (Monotypic) Genus: Polihierax (Pygmy Falcons) (2 species) (sometimes includes Neohierax) Genus: Microhierax (Typical Falconets) (5 species) Genus: Falco (True Falcons, Hobbies and Kestrels) (37 species)