Accipitriformes
Encyclopedia
The Accipitriformes is an order
that has been proposed to include most of the diurnal birds of prey: hawk
s, eagle
s, vulture
s, and many others, about 225 species
in all. For a long time, the majority view has been to include them with the falcon
s in the Falconiformes
, but some authorities have recognized a separate Accipitriformes. A recent DNA
study has indicated that falcons are not closely related to the Accipitriformes, being instead related to parrot
s and passerine
s. Since then the split
(but not the placement of the falcons next to the parrots or passerines) has been adopted by the American Ornithologists' Union
's South American Classification Committee (SACC), its North American Classification Committee (NACC), and the International Ornithological Congress (IOC).
The DNA-based proposal and the NACC and IOC classifications include the New World vultures in the Accipitriformes, an approach followed in this article. The SACC classifies the New World vultures as a separate order. The placement of the New World vultures has been unclear since the early 1990s.
(the possibly basal genus Masillaraptor
from the Messel Pit
) and typically have a sharply hooked beak
with a cere
(soft mass) on the proximodorsal surface, housing the nostril
s. Their wing
s are long and fairly broad, suitable for soaring flight, with the outer 4–6 primaries emarginated.
Accipitriformes have strong legs and feet with raptor
ial claw
s and an opposable hind claw. Almost all Accipitriformes are carnivorous
, hunting by sight during the day or at twilight. They are exceptionally long-lived, and most have low reproductive 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
is sometimes most extreme in specialized bird-eaters, such as the Accipiter
hawks, and borders on non-existent among the vulture
s. Monogamy
is the general rule, although an alternative mate is often selected if one dies.
The Accipitriformes are among the most diverse orders in size, from the small sparrowhawk
s to the biggest Old World vultures, and the somewhat bigger Andean Condor
(possibly the largest flying bird extant) if the Cathartidae are included.
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
that has been proposed to include most of the diurnal birds of prey: hawk
Hawk
The term hawk can be used in several ways:* In strict usage in Australia and Africa, to mean any of the species in the subfamily Accipitrinae, which comprises the genera Accipiter, Micronisus, Melierax, Urotriorchis and Megatriorchis. The large and widespread Accipiter genus includes goshawks,...
s, eagle
Eagle
Eagles are members of the bird family Accipitridae, and belong to several genera which are not necessarily closely related to each other. Most of the more than 60 species occur in Eurasia and Africa. Outside this area, just two species can be found in the United States and Canada, nine more in...
s, vulture
Vulture
Vulture is the name given to two groups of convergently evolved scavenging birds, the New World Vultures including the well-known Californian and Andean Condors, and the Old World Vultures including the birds which are seen scavenging on carcasses of dead animals on African plains...
s, and many others, about 225 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
in all. For a long time, the majority view has been to include them with the falcon
Falcon
A falcon is any species of raptor in the genus Falco. The genus contains 37 species, widely distributed throughout Europe, Asia, and North America....
s in the Falconiformes
Falconiformes
The order Falconiformes is a group of about 290 species of birds that comprises the diurnal birds of prey. Raptor classification is difficult and the order is treated in several ways.- Classification problems :...
, but some authorities have recognized a separate Accipitriformes. A recent DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
study has indicated that falcons are not closely related to the Accipitriformes, being instead related to parrot
Parrot
Parrots, also known as psittacines , are birds of the roughly 372 species in 86 genera that make up the order Psittaciformes, found in most tropical and subtropical regions. The order is subdivided into three families: the Psittacidae , the Cacatuidae and the Strigopidae...
s and passerine
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
s. Since then the split
Lumpers and splitters
Lumping and splitting refers to a well-known problem in any discipline which has to place individual examples into rigorously defined categories. The lumper/splitter problem occurs when there is the need to create classifications and assign examples to them, for example schools of literature,...
(but not the placement of the falcons next to the parrots or passerines) has been adopted by the American Ornithologists' Union
American Ornithologists' Union
The American Ornithologists' Union is an ornithological organization in the USA. Unlike the National Audubon Society, its members are primarily professional ornithologists rather than amateur birders...
's South American Classification Committee (SACC), its North American Classification Committee (NACC), and the International Ornithological Congress (IOC).
The DNA-based proposal and the NACC and IOC classifications include the New World vultures in the Accipitriformes, an approach followed in this article. The SACC classifies the New World vultures as a separate order. The placement of the New World vultures has been unclear since the early 1990s.
Characteristics
Accipitriformes are known from the Middle EoceneEocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
(the possibly basal genus Masillaraptor
Masillaraptor
Masillaraptor is an extinct genus of basal falconiform from the Middle Eocene, a long-legged relative of the living falcons. Classifying the Falconiformes is confusing, since Europe has placed the families into two orders .- Etymology :Masillaraptor comes from the Latin word masilla, which is the...
from the Messel Pit
Messel pit
The Messel Pit is a disused quarry near the village of Messel, about southeast of Frankfurt am Main, Germany. Bituminous shale was mined there. Because of its abundance of fossils, it has significant geological and scientific importance...
) and typically have a sharply hooked beak
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
with a cere
Cère
The Cère is a long river in south-western France, left tributary of the Dordogne River. Its source is in the south-western Massif Central, near the mountain Plomb du Cantal...
(soft mass) on the proximodorsal surface, housing the nostril
Nostril
A nostril is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation...
s. Their wing
Wing
A wing is an appendage with a surface that produces lift for flight or propulsion through the atmosphere, or through another gaseous or liquid fluid...
s are long and fairly broad, suitable for soaring flight, with the outer 4–6 primaries emarginated.
Accipitriformes have strong legs and feet with raptor
Bird of prey
Birds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as birds that primarily hunt vertebrates, including other birds. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh....
ial claw
Claw
A claw is a curved, pointed appendage, found at the end of a toe or finger in most mammals, birds, and some reptiles. However, the word "claw" is also often used in reference to an invertebrate. Somewhat similar fine hooked structures are found in arthropods such as beetles and spiders, at the end...
s and an opposable hind claw. Almost all Accipitriformes are carnivorous
Carnivore
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...
, hunting by sight during the day or at twilight. They are exceptionally long-lived, and most have low reproductive 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
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
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
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
is sometimes most extreme in specialized bird-eaters, such as the Accipiter
Accipiter
The genus Accipiter is a group of birds of prey in the family Accipitridae, many of which are named as goshawks and sparrowhawks. They can be anatomically distinguished from their relatives by the lack of a procoracoid foramen. Two small and aberrant species usually placed here do possess a large...
hawks, and borders on non-existent among the vulture
Vulture
Vulture is the name given to two groups of convergently evolved scavenging birds, the New World Vultures including the well-known Californian and Andean Condors, and the Old World Vultures including the birds which are seen scavenging on carcasses of dead animals on African plains...
s. Monogamy
Monogamy
Monogamy /Gr. μονός+γάμος - one+marriage/ a form of marriage in which an individual has only one spouse at any one time. In current usage monogamy often refers to having one sexual partner irrespective of marriage or reproduction...
is the general rule, although an alternative mate is often selected if one dies.
The Accipitriformes are among the most diverse orders in size, from the small sparrowhawk
Sparrowhawk
The Eurasian Sparrowhawk is a small bird of prey in the family Accipitridae. Adult male Eurasian Sparrowhawks have bluish grey upperparts and orange-barred underparts; females and juveniles are brown above with brown barring below...
s to the biggest Old World vultures, and the somewhat bigger Andean Condor
Andean Condor
The Andean Condor is a species of South American bird in the New World vulture family Cathartidae and is the only member of the genus Vultur...
(possibly the largest flying bird extant) if the Cathartidae are included.
Taxonomy
Order Accipitriformes- AccipitridaeAccipitridaeThe Accipitridae, one of the two major families within the order Accipitriformes , are 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-sized mammals, with a number feeding on carrion and a...
(buzzards, eagleEagleEagles are members of the bird family Accipitridae, and belong to several genera which are not necessarily closely related to each other. Most of the more than 60 species occur in Eurasia and Africa. Outside this area, just two species can be found in the United States and Canada, nine more in...
s, harriersHarrier (bird)A harrier is any of the several species of diurnal hawks forming the Circinae sub-family of the Accipitridae family of birds of prey. Harriers characteristically hunt by flying low over open ground, feeding on small mammals, reptiles, or birds....
, hawkHawkThe term hawk can be used in several ways:* In strict usage in Australia and Africa, to mean any of the species in the subfamily Accipitrinae, which comprises the genera Accipiter, Micronisus, Melierax, Urotriorchis and Megatriorchis. The large and widespread Accipiter genus includes goshawks,...
s, kiteKite (bird)Kites are raptors with long wings and weak legs which spend a great deal of time soaring. Most feed mainly on carrion but some take various amounts of live prey.They are birds of prey which, along with hawks and eagles, are from the family Accipitridae....
s, Old World vultureOld World vultureOld World vultures belong to the family Accipitridae, which also includes eagles, buzzards, kites, and hawks.Old World vultures are not closely related to the superficially similar New World vultures and condors, and do not share that group's good sense of smell. The similarities between the two...
s) - Cathartidae (New World vultureNew World vultureThe New World Vulture or Condor family Cathartidae contains seven species in fivegenera, all but one of which are monotypic. It includes five vultures and two condors found in warm and temperate areas of the Americas....
s including condorCondorCondor is the name for two species of New World vultures, each in a monotypic genus. They are the largest flying land birds in the Western Hemisphere.They are:* The Andean Condor which inhabits the Andean mountains....
s) - Pandionidae (Osprey)
- Sagittariidae (Secretary Bird)