The Accipitriformes (; from

Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...

''accipiter''/''accipitri-'' "hawk", and

New Latin New Latin (also called Neo-Latin or Modern Latin) is the revival of Literary Latin used in original, scholarly, and scientific works since about 1500. Modern scholarly and technical nomenclature, such as in zoological and botanical taxonomy ...

''-formes'' "having the form of") are an

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

of birds that includes most of the diurnal

birds of prey Birds of prey or predatory birds, also known as raptors, are hypercarnivorous bird species that actively hunt and feed on other vertebrates (mainly mammals, reptiles and other smaller birds). In addition to speed and strength, these predat ...

, including

hawk Hawks are birds of prey of the family Accipitridae. They are widely distributed and are found on all continents except Antarctica. * The subfamily Accipitrinae includes goshawks, sparrowhawks, sharp-shinned hawks and others. This subfa ...

eagle Eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, some of which are closely related. Most of the 68 species of eagle are from Eurasia and Africa. Outside this area, j ...

vulture A vulture is a bird of prey that scavenges on carrion. There are 23 extant species of vulture (including Condors). Old World vultures include 16 living species native to Europe, Africa, and Asia; New World vultures are restricted to North and ...

s, and

kites A kite is a tethered heavier-than-air or lighter-than-air craft with wing surfaces that react against the air to create lift and drag forces. A kite consists of wings, tethers and anchors. Kites often have a bridle and tail to guide the face ...

, but not

falcon Falcons () are birds of prey in the genus ''Falco'', which includes about 40 species. Falcons are widely distributed on all continents of the world except Antarctica, though closely related raptors did occur there in the Eocene. Adult falcons ...

s. For a long time, the majority view was to include them with the falcons in the

Falconiformes The order Falconiformes () is represented by the extant family Falconidae (falcons and caracaras) and a handful of enigmatic Paleogene species. Traditionally, the other bird of prey families Cathartidae (New World vultures and condors), Sagitt ...

, but many authorities now recognize a separate Accipitriformes. A DNA study published in 2008 indicated that falcons are not closely related to the Accipitriformes, being instead more closely related to

parrot Parrots, also known as psittacines (), are birds of the roughly 398 species in 92 genera comprising the order Psittaciformes (), found mostly in tropical and subtropical regions. The order is subdivided into three superfamilies: the Psittacoide ...

s and

passerine A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by th ...

s. Since then, the split and the placement of the falcons next to the parrots in taxonomic order has been adopted by the

American Ornithological Society The American Ornithological Society (AOS) is an ornithological organization based in the United States. The society was formed in October 2016 by the merger of the American Ornithologists' Union (AOU) and the Cooper Ornithological Society. Its m ...

's South American Classification Committee (SACC), its North American Classification Committee (NACC), and the International Ornithological Congress (IOC). The British Ornithologists' Union already recognized the Accipitriformes, and has adopted the move of Falconiformes. The DNA-based proposal and the NACC and IOC classifications include the New World vultures in the Accipitriformes, while the SACC classifies the New World vultures as a separate order, the Cathartiformes.

Characteristics

The Accipitriformes are known from the Middle

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...

and typically have a sharply hooked

beak The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for fo ...

with a soft cere housing the

nostril A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbi ...

s. Their

wing A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is e ...

s are long and fairly broad, suitable for soaring flight, with the outer four to six primary feathers emarginated. They have strong legs and feet with raptorial

claw A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or tarsus ...

s and opposable hind claws. Almost all Accipitriformes are

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other ...

, hunting by sight during the day or at twilight. They are exceptionally long-lived, and most have low

reproductive The reproductive system of an organism, also known as the genital system, is the biological system made up of all the anatomical organs involved in sexual reproduction. Many non-living substances such as fluids, hormones, and pheromones are a ...

rates. The young have a long, very fast-growing fledgling stage, followed by 3–8 weeks of nest care after first flight, and 1 to 3 years as sexually immature adults. The sexes have conspicuously different sizes and sometimes a female is more than twice as heavy as her mate. This

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...

is sometimes most extreme in specialized bird-eaters, such as the ''

Accipiter ''Accipiter'' is a genus of birds of prey in the family Accipitridae. With 51 recognized species it is the most diverse genus in its family. Most species are called goshawks or sparrowhawks, although almost all New World species (excepting th ...

'' hawks.

Monogamy Monogamy ( ) is a form of dyadic relationship in which an individual has only one partner during their lifetime. Alternately, only one partner at any one time ( serial monogamy) — as compared to the various forms of non-monogamy (e.g., pol ...

is the general rule, although an alternative mate is often selected if one dies.

Taxonomy

Accipitriformes, currently with 262 species and 75 genera in 4 extant families and possibly 1 extinct family, is the largest diurnal raptor order. DNA sequence analyses suggest that divergences within Accipitriformes began around the Eocene/Oligocene boundary about 34 mya, with the split of the group including genera ''Elanus'' and ''Gampsonyx'' from the other Accipitriformes genera. The order includes the following families: Order Accipitriformes *

Accipitridae The Accipitridae is one of the three families within the order Accipitriformes, and is a family of small to large birds with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-s ...

(

s, harriers,

kite A kite is a tethered heavier-than-air or lighter-than-air craft with wing surfaces that react against the air to create lift and drag forces. A kite consists of wings, tethers and anchors. Kites often have a bridle and tail to guide the fac ...

s) *

Pandionidae ''Pandion'' is a genus of birds of prey, known as ospreys, the only genus of family Pandionidae. Most taxonomic treatments have regarded this genus as describing a single extant species, separated to subspecies or races, while some treatments rec ...

(ospreys) (1 or 2 species) *

Cathartidae The New World vulture or condor family, Cathartidae, contains seven extant species in five genera. It includes five extant vultures and two extant condors found in warm and temperate areas of the Americas. The "New World" vultures were widespr ...

(Cathartid vultures and condors) * Sagittariidae (secretarybird) *Possibly includes the extinct

Teratornithidae Teratornithidae is an extinct family of very large birds of prey that lived in North and South America from the Late Oligocene to the Late Pleistocene. They include some of the largest known flying birds. Taxonomy Teratornithidae are related t ...

as well. For a complete list of species, see list of Accipitriformes species. Phylogeny based on Nagy, J. & Tökölyi, J. (2014).Nagy, Jenő & Tökölyi, Jacint (2014
Phylogeny, historical biogeography and the evolution of migration in accipitrid birds of prey (Aves: Accipitriformes)
''Ornis Hungarica'', 22(1): 15–35.DOI: 10.2478/orhu-2014-0008

Footnotes

References

* * Full text vi
AOUCOPOBioOne
* Includes a review of recent literature on the controversy. * * * * * * Falconiformes was resequenced in version 4.1 (Jan 7, 2014) * * * * *

External links

* * {{Authority control Extant Lutetian first appearances Bird orders Eocene taxonomic orders Oligocene taxonomic orders Miocene taxonomic orders Pliocene taxonomic orders Pleistocene taxonomic orders Holocene taxonomic orders Taxa named by Louis Jean Pierre Vieillot