The

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

''Hieraaetus'', sometimes known as small eagles or hawk-eagles, denotes a group of smallish

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 ...

s usually placed in the accipitrid subfamilies ButeoninaeDigitized copy
/ref> or Aquilinae. They are medium-sized birds of prey inhabiting Europe, Asia, Africa, New Guinea and Australia. A recently-extinct species, the New Zealand Haast's eagle, was the largest eagle ever known, weighing up to , with a wingspan.

Taxonomy and species

The genus ''Hieraaetus'' was introduced in 1844 by the German naturalist

Johann Jakob Kaup Johann Jakob von Kaup (10 April 1803 – 4 July 1873) was a German naturalist. A proponent of natural philosophy, he believed in an innate mathematical order in nature and he attempted biological classifications based on the Quinarian system. Kau ...

with 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 ...

as the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specim ...

. The name combines the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic pe ...

''hierax'' meaning "hawk" with ''aetos'' meaning "eagle". Molecular genetic research has found ''Hieraaetus'' to be polyphyletic with '' Aquila''. '' Hieraaetus kienerii'' was found to be most distinct,proof
/ref> and has been assigned to a separate genus, '' Lophotriorchis''.PDFalternate location
"Despite the fact that its sister group has not been identified so far, it is advisable to separate it from the genus ''Hieraaetus'' and treat it as a different genus. ... Therefore, we propose to give the monotypic species ''Hieraaetus kienerii'' the resurrected name ''Lophotriorchis'' Sharpe, 1874." After DNA sequences from remains of the extinct giant Haast's eagle were found to be similar to those of the little eagle, it has been reclassified from ''Harpagornis moorei'' to the genus ''Hieraeetus''. The British Ornithological Union moved Bonelli's and booted eagles to ''Aquila'' in 2005, but was silent on the position of the non-European Ayres', little, and pygmy eagles. This could create a taxonomic problem: the booted eagle is the

of ''Hieraaetus'', moving it would make that name a

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linn ...

of ''Aquila''. Consequently, should any other hawk-eagles be retained as a distinct group, they would need to get a different genus name. As of 2014, the BOU lists the booted eagle on their Category D and E lists as ''H. pennatus'', not ''A. pennata''. Christidis and Boles (2008) used an alternative approach. Accepting that both ''Aquila'' and ''Hieraaetus'' are polyphyletic, they moved ''spilogaster'' and ''fasciatus'' to the genus ''Aquila'' and retained the other former ''Hieraaetus'' group along with ''morphnoides'' and ''Aquila wahlbergi'' within the new delimitation of ''Hieraaetus''.Les Christidis & Walter E Boles (2008) Systematics and Taxonomy of Australian Birds. CSIRO publishing. Sometimes the entire genus is merged into ''Aquila''. This was the approach taken with ''The Clements Checklist'' between 2001 and 2009: starting in the 2001 revisions to the 5th edition, (See also similar pages for the other species.) and retained in the printed 6th edition of 2007. ''The Clements Checklist'', in its 2009 revisions, followed the same approach as Christidis & Boles, moving ''Aquila wahlbergi'' into ''Hieraaetus''; restoring the booted, little and Ayres' eagles back to ''Hieraaetus''. The pygmy eagle, or New Guinea hawk-eagle, ''H. morphnoides weiskei'' was formerly considered a subspecies of the little eagle ''H. morphnoides''; it has been recognized as a separate species by some authorities. The genus contains five species.

Extinct species

Former species

Some authorities retain Bonelli's eagle and the African hawk-eagle in ''Hieraaetus''. Also, some retain Wahlberg's eagle in ''Aquila'', whilst still recognizing ''Hieraaetus'' as a separate genus.

Notes

References

* Helbig AJ, Kocum A, Seibold I & Braun MJ (2005) A multi-gene phylogeny of aquiline eagles (Aves: Accipitriformes) reveals extensive paraphyly at the genus level. Molecular Phylogenetics and Evolution 35(1):147-16
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* {{Taxonbar, from=Q255035 Aquilinae Bird genera