Booted eagles are

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, just ...

s that have fully feathered tarsi. That is, their legs are covered with feathers down to the feet. Most other accipitrids have bare lower legs, scaled rather than feathered. They may be treated as an informal group, as distinct from "fish eagles" (or "sea eagles"), "snake eagles", and "giant forest eagles". They may also be treated as a formal taxon, either as a tribe (Aquililae) or subfamily (Aquilinae). The booted eagles, sea eagles, harpy eagles and buteonine hawks are heavily built birds that have traditionally been classified together in the large subfamily Buteoninae. In 2005, Heather Lerner and David Mindell proposed separating the eagles into their own subfamilies Aquilinae, Haliaeetinae, and Harpiinae, leaving only the buteo–buteogallus clade in a more restricted Buteoninae. Included in the booted eagles are the genera ''Aquila'', ''Hieraaetus'' and ''Clanga''; all species described as "hawk eagles" including the genera ''

Spizaetus ''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 ...

'' and ''

Nisaetus ''Nisaetus'' (Crested hawk-eagles group) is a genus of subfamily Aquilinae found mainly in tropical Asia. They were earlier placed within the genus ''Spizaetus'' but molecular studies show that the Old World representatives were closer to the ge ...

''; as well as assorted monotypical genera such as '' Oroaetus'', ''

Lophaetus The long-crested eagle (''Lophaetus occipitalis'') is an African bird of prey. Like all eagles, it is in the family Accipitridae. It is currently placed in a monotypic genus ''Lophaetus''. It is characterized by the feathers making up the shaggy ...

'', ''

Stephanoaetus ''Stephanoaetus'' is a genus of very large birds of prey from Sub-Saharan Africa and Madagascar. Only one of the two known species is extant. Species * Crowned eagle or crowned hawk-eagle (''Stephanoaetus coronatus''). * † Malagasy crowned ea ...

'', '' Polemaetus'', '' Lophotriorchis'' and '' Ictinaetus''.

Hawk eagles

''Aquila'' eagles

The genus '' Aquila'' is distributed across every continent but for

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

and

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...

. Up to 20 species have been classified in the genus but the taxonomic placement of some of the traditionally included species has recently been questioned. Traditionally, the ''Aquila'' eagles have been grouped superficially as largish, mainly brownish or dark-colored booted eagles that vary little in transition from their juvenile to their adult plumages. Genetic research has recently indicated a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

containing the near-circumpolar

golden eagle The golden eagle (''Aquila chrysaetos'') 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 bird of p ...

(''Aquila chrysaetos''),

Verreaux's eagle Verreaux's eagle (''Aquila verreauxii'') 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 Indian black eagle (''Ictinaetus malayensis''), which lives far to t ...

(''A. verreauxii'') of Africa, Asian

Gurney's eagle Gurney's eagle (''Aquila gurneyi'') is a large eagle in the family Accipitridae. It is found in New Guinea and Wallacea, and is an occasional vagrant to Australia. The common name and Latin binomial commemorate the British banker and amateur or ...

(''A. gurneyi'') and the Australian

wedge-tailed eagle The wedge-tailed eagle (''Aquila audax'') is the largest bird of prey in the continent of Australia. It is also found in southern New Guinea to the north and is distributed as far south as the state of Tasmania. Adults of this species have lon ...

(''A. audax''). This identification of this particular clade has long been suspected based on similar morphological characteristics amongst these large-bodied species. More surprisingly, the smaller, much paler-bellied species pair

Bonelli's eagle The Bonelli's eagle (''Aquila fasciata'') 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 ...

(''A. fasciatus'') and

African hawk-eagle The African hawk-eagle (''Aquila spilogaster'') is a large bird of prey. Like all eagles, it belongs to the family ''Accipitridae''. This species’ feathered legs mark it as a member of the Aquilinae subfamily.Lerner, H., Christidis, L., Gamauf, ...

(''A. spilogaster''), previously included in the genus ''Hieraaetus'', have been revealed to be genetically much closer to the Verreaux's and golden eagle lineage than to other species traditionally included in the genus ''Aquila''. Other largish ''Aquila'' species, the

eastern imperial eagle The eastern imperial eagle (''Aquila heliaca'') is a large bird of prey that breeds in southeastern Europe and extensively through West and Central Asia. Most populations are migratory and winter in northeastern Africa, the Middle East and South ...

(''A. heliaca''), the

Spanish imperial eagle The Spanish imperial eagle (''Aquila adalberti''), also known as the Spanish eagle or Adalbert's eagle, is a species of eagle native to the Iberian Peninsula. The binomial commemorates Prince Adalbert of Bavaria. Due to its distinct “epaulet ...

(''A. adaberti''), the

tawny eagle The tawny eagle (''Aquila rapax'') is a large bird of prey. Like all eagles, it belongs to the family ''Accipitridae''. Its heavily feathered legs mark it as a member of the subfamily Aquilinae, also known as booted eagles.Helbig, A. J., Kocum, ...

(''A. rapax'') and the

steppe eagle The steppe eagle (''Aquila nipalensis'') is a large bird of prey. Like all eagles, it belongs to the family Accipitridae. The steppe eagle's well-feathered legs illustrate it to be a member of the subfamily Aquilinae, also known as the "booted ...

s (''A. nipalensis''), are now thought to be separate, close-knit clade, which attained some similar characteristics to the golden eagle clade via convergent evolution.

Spotted eagles

Genetically, the "spotted eagles" ('' A. pomarina, A. hasata & A. clanga''), have been discovered to be more closely related to the

long-crested eagle The long-crested eagle (''Lophaetus occipitalis'') is an African bird of prey. Like all eagles, it is in the family Accipitridae. It is currently placed in a monotypic genus ''Lophaetus''. It is characterized by the feathers making up the shaggy ...

(''Lophaetus occipitalis'') and the

black eagle The black eagle (''Ictinaetus malaiensis'') is a bird of prey. Like all eagles, it is in the family Accipitridae, and is the only member of the genus ''Ictinaetus''. They soar over forests in the hilly regions of tropical and subtropical South ...

(''Ictinaetus malaiensis''), and many generic reassignments have been advocated. Some authorities place the spotted eagles in a separate genus, '' Clanga''.

Hieraaetus

The genus ''

Hieraaetus 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. They are medium-sized birds of prey inhabiting Europe, Asia, Afric ...

'', including the

booted eagle The booted eagle (''Hieraaetus pennatus'', also classified as ''Aquila pennata'') 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 ...

(''H. pennatus''),

little eagle The little eagle (''Hieraaetus morphnoides'') is a very small eagle native to Australia, measuring 45–55 cm (17–21.5 inches) in length and weighing 815 g (1.8 lb), roughly the size of a peregrine falcon. It tends to inhabit open w ...

(''H. morphnoides'') and

Ayres's hawk-eagle Ayres's hawk-eagle (''Hieraaetus ayresii''), also referred to as Ayres' eagle,Newman, K (1998) Newman's Birds of Southern Africa. Halfway House: Southern Book Publishers. . is a medium-sized bird of prey in the family Accipitridae. It is native t ...

(''H. ayresii''), consists of much smaller species, that are in fact the smallest birds called eagles outside of the unrelated ''

Spilornis ''Spilornis'' is a genus of bird of prey in the family Accipitridae. As adults all have dark crowns, and bright yellow eyes and cere.Ferguson-Lees & Christie (2001). ''Raptors of the World.'' Christopher Helm, London. These medium-sized raptors ...

'' serpent-eagle genus. This genus has recently been eliminated by some authorities and its members included in ''Aquila'', although not all ornithological unions have followed this suit in this re-classification. The small-bodied

Wahlberg's eagle Wahlberg's eagle (''Hieraaetus wahlbergi'') 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 ...

(''H. wahlbergi'') has been traditionally considered an ''Aquila'' species due to its lack of change from juvenile to adult plumage and brownish color, but it is genetically aligned to the ''Hieraaetus'' lineage.

Cassin's hawk-eagle Cassin's hawk-eagle (''Aquila africana'') 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 ...

(''H. africanus'') is also probably closely related to the ''Hieraaetus'' group rather than the ''Spizaetus/Nisaetus'' "hawk-eagle" group (in which it was previously classified) which is not known to have radiated to Africa.

Notes

References

{{Accipitriformes Eagles Bird common names