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Eagle is the common name for the golden eagle, bald eagle, and other birds of prey in the family of the Accipitridae. Eagles belong to several groups of genera, some of which are closely related. True eagles comprise the genus Aquila. Most of the 68 species of eagles are from Eurasia and Africa. Outside this area, just 14 species can be found—two in North America, nine in Central and South America, and three in Australia.
The Accipitridae is one of the three families within the order Accipitriformes, and is a family of small to large birds of prey 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 few feeding on fruit. The Accipitridae have a cosmopolitan distribution, being found on all the world's continents and a number of oceanic island groups. Some species are migratory. The family contains 256 species which are divided into 12 subfamilies and 75 genera.
The golden eagle is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of prey in the Northern Hemisphere. These birds are dark brown, with lighter golden-brown plumage on their napes. Immature eagles of this species typically have white on the tail and often have white markings on the wings. Golden eagles use their agility and speed combined with powerful feet and large, sharp talons to hunt a variety of prey, mainly hares, rabbits, and marmots and other ground squirrels. Golden eagles maintain home ranges or territories that may be as large as 200 km2 (77 sq mi). They build large nests in cliffs and other high places to which they may return for several breeding years. Most breeding activities take place in the spring; they are monogamous and may remain together for several years or possibly for life. Females lay up to four eggs, and then incubate them for six weeks. Typically, one or two young survive to fledge in about three months. These juvenile golden eagles usually attain full independence in the fall, after which they wander widely until establishing a territory for themselves in four to five years.
The booted eagle is a medium-sized mostly migratory bird of prey with a wide distribution in the Palearctic and southern Asia, wintering in the tropics of Africa and Asia, with a small, disjunct breeding population in south-western Africa. Like all eagles, it belongs to the family Accipitridae.
The Buteoninae are a subfamily of birds of prey which consists of medium to large, broad-winged species.
Wahlberg's eagle is a bird of prey that is native to sub-Saharan Africa, where it is a seasonal migrant in the woodlands and savannas. It is named after the Swedish naturalist Johan August Wahlberg. Like all eagles, it belongs to the family Accipitridae.
The changeable hawk-eagle(Nisaetus cirrhatus) or crested hawk-eagle is a large bird of prey species of the family Accipitridae. More informal or antiquated English common names include the marsh hawk-eagle or Indian crested hawk-eagle. It is a member of the subfamily Aquilinae, with signature feathers, absent in tropical raptors from outside this subfamily, covering the tarsus. It was formerly placed in the genus Spizaetus, but studies pointed to the group being paraphyletic resulting in the Old World members being placed in Nisaetus and separated from the New World species. It is a typical “hawk-eagle” in that it is an agile forest-dwelling predator and like many such eagles readily varies its prey selection between birds, mammals or reptiles as well as other vertebrates. Among the members of its genus, the changeable hawk-eagle stands out as the most widely distributed, adaptable and abundant species. Individuals show a wide range of variation in plumage from pale to dark, varying with moult and age giving rise to the name "changeable".
The mountain hawk-eagle or Hodgson's hawk-eagle, is a large bird of prey native to Asia. The latter name is in reference to the naturalist, Brian Houghton Hodgson, who described the species after collecting one himself in the Himalayas. A less widely recognized common English name is the feather-toed eagle. Like all eagles, it is in the family Accipitridae. Its feathered tarsus marks this species as a member of the subfamily Aquilinae. It is a confirmed breeding species in the northern part of the Indian subcontinent, from India, Nepal through Bangladesh to Thailand, Taiwan, Vietnam and Japan, although its distribution could be wider still as breeding species. Like other Asian hawk-eagles, this species was earlier treated under the genera of Spizaetus but genetic studies have shown this group to be paraphyletic, resulting in the Old World members being placed in Nisaetus and separated from the New World species. As is typical of hawk-eagles, the mountain hawk-eagle is a forest dwelling opportunistic predator who readily varies its prey selection between birds, mammals and reptiles along with other vertebrates. Although classified currently as a least-concern species due its persistence over a rather wide distribution, this species is often quite rare and scarce and seems to be decreasing, especially in response to large-scale habitat degradation and deforestation.
The rufous-bellied eagle or rufous-bellied hawk-eagle is a bird of prey in the family Accipitridae that is found in the forested regions of tropical Asia. Relatively small for eagles and contrastingly patterned like a falcon, this species was earlier placed in the genus Hieraaetus and sometimes also in the genus Aquila but thought to be distinctive enough to belong to a separate genus.
Bonelli's eagle is a large bird of prey. The common name of the bird commemorates the Italian ornithologist and collector Franco Andrea Bonelli. Bonelli is credited with gathering the type specimen, most likely from an exploration of Sardinia. Some antiquated texts also refer to this species as the crestless hawk-eagle. Like all eagles, Bonelli's eagle belongs to the family Accipitridae. Its feathered legs marked it as member of the Aquilinae or booted eagle subfamily. This species breeds from Southern Europe, Africa on the montane perimeter of the Sahara Desert, and across the Indian Subcontinent to Indonesia. In Eurasia, this species may be found as far west as Portugal and as far east as southeastern China and Thailand. It is usually a resident breeder. Bonelli's eagle is often found in hilly or mountainous habitats, with rocky walls or crags, from sea level to 1,500 m (4,900 ft). Habitats are often open to wooded land and can occur in arid to semi-moist climate. This eagle, though it can be considered partially opportunistic, is something of a specialist predator of certain birds and mammals, especially rabbits, galliforms and pigeons. On evidence, when staple prey populations decline or are locally scarce, Bonelli's eagle switch to being an opportunistic predator of a wide variety of birds. Despite its persistence over a large range and its continued classification as a least concern species by the IUCN, Bonelli's eagle has declined precipitously in various parts of its range, including almost all of its European distribution, and may face potential local extinction. The species' declines are due to widespread habitat destruction, electrocution from electricity pylons as well as persistent persecution.
Verreaux's eagle is a large, mostly African, bird of prey. It is also called the black eagle, especially in southern Africa, not to be confused with the black eagle of south and southeast Asia. The Verreaux's eagle lives in hilly and mountainous regions of southern and eastern Africa, and very locally in the Middle East.
Aquila is the genus of true eagles. The genus name is Latin for "eagle", possibly derived from aquilus, "dark in colour". It is often united with the sea eagles, buteos, and other more heavyset Accipitridae, but more recently they appear to be less distinct from the slenderer accipitrine hawks than previously believed. Eagles are not a natural group but denote essentially any bird of prey large enough to hunt sizeable vertebrate prey.
The little eagle is a very small eagle endemic to Australia.
Spizaetus is the typical hawk-eagle birds of prey genus found in the tropics of the Americas. It was however used to indicate a group of tropical eagles that included species occurring in southern and southeastern Asia and one representative of this genus in the rainforests of West Africa. The Old World species have been separated into the genus Nisaetus. Several species have a prominent head crest. These are medium to large-sized raptors, most being between 55 and 75 cm long, and tend to be long-tailed and slender.
The genus Hieraaetus, sometimes known as small eagles or hawk-eagles, denotes a group of smallish eagles usually placed in the accipitrid subfamilies Buteoninae or Aquilinae.
The pygmy eagle or New Guinea hawk-eagle is a bird of prey found in New Guinea. Its natural habitats are primarily subtropical or tropical moist lowland forest and subtropical or tropical moist montane forest. It is the one of the smallest species of eagle.
Cassin's hawk-eagle or Cassin's eagle, is a relatively small eagle in the family Accipitridae. Its feathered legs mark it as member of the Aquilinae or booted eagle subfamily. A forest-dependent species, it occurs in primary rainforests across western, central and (marginally) eastern Africa where it preys on birds and tree squirrels. It was named after John Cassin who first described it in 1865. Due to widespread habitat destruction, its populations are steadily declining but have not yet warranted upgrading its status from Least Concern.
Nisaetus, the crested hawk-eagles, is a genus of raptor in the subfamily Aquilinae, found mainly in tropical Asia. They were earlier placed within the genus Spizaetus but molecular studies show that the Old World representatives of that genus are closer to the genus Ictinaetus than to the New World Spizaetus. They are slender-bodied, medium-sized hawk-eagles with rounded wings, long feathered legs, barred wings, crests and usually adapted to forest habitats.
The Aquilinae are a subfamily of eagles of the family Accipitridae. The general common name used for members of this subfamily is "booted eagle", although this is also the common name of a member of the subfamily. At one point, this subfamily was considered inclusive with the Buteoninae based probably on some shared morphological characteristics. However, research on the DNA of the booted eagles has shown that they are a monophyletic group that probably have had millions of years of separation from other extant forms of accipitrid.
References
- ↑ Stalcup, Carolyn. "All About Eagles". The American Eagle Foundation. Archived from the original on 2014-07-14. Retrieved 25 May 2014.
- 1 2 3 4 Lerner, Heather R.L.; Mindell, David P. (2005). "Phylogeny of eagles, Old World vultures, and other Accipitridae based on nuclear and mitochondrial DNA" (PDF). Molecular Phylogenetics and Evolution. 37 (2): 327–346. Bibcode:2005MolPE..37..327L. doi:10.1016/j.ympev.2005.04.010. PMID 15925523 . Retrieved 2013-04-22.
- ↑ Eagles, Hawks and Falcons of the World by Leslie Brown & Dean Amadon. The Wellfleet Press (1986), ISBN 978-1555214722.
- 1 2 Watson, Jeff (2010). The Golden Eagle. A&C Black. ISBN 978-1-4081-1420-9.
- 1 2 3 4 Helbig, A.J., Kocum, A., Seibold, I. & Braun, M.J. (2005). "A multi-gene phylogeny of aquiline eagles (Aves: Accipitriformes) reveals extensive paraphyly at the genus level" (PDF). Molecular Phylogenetics and Evolution. 35 (1). Elsevier: 147–164. doi:10.1016/j.ympev.2004.10.003. PMID 15737588. Archived from the original (PDF) on 2012-08-13. Retrieved 2013-04-23.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ↑ "Lophaetus pomarinus". The Peregrine Fund. Retrieved 2013-04-22.
- ↑ "Aquila morphnoides". The Peregrine Fund. Archived from the original on 2012-10-28. Retrieved 2013-04-22.
- ↑ "Aquila wahlbergi". The Peregrine Fund. Retrieved 2013-04-23.
- ↑ "Aquila africana". The Peregrine Fund. Archived from the original on 2012-10-26. Retrieved 2013-04-23.