Aquila – True Eagles

Aquila is the genus of true eagles. It is often united with the buteos, sea eagles and other more heavyset Accipitridae, but more recently it appears as if they are less distinct from the more slender accipitrine hawks than believed. Eagles are not a natural group but denote essentially any bird of prey large enough to hunt sizeable (about 50 cm long or more overall) vertebrate prey.

Species

Aquila belongs to an extremely close-knit group of “typical” eagles. These include genera like Hieraaetus, Lophaetus, Ictinaetus and the extinct Harpagornis, and all these appear to be paraphyletic with regards to the traditional Aquila.

Especially some, if not all, species of Hieraaetus, separated primarily due to their smaller size, seem to belong here. The entire “typical eagle” group is in need of a thorough revision, and thus this species list cannot be more than a tentative one at present.

Steppe Eagle (Aquila nipalensis)

Most problematic is certainly Hieraeetus, the hawk-eagles. It is known that the type species, the Booted Eagle, is very close to some Aquila eagles.

Other hawk-eagles might indeed be distinct enough to warrant generic separation, but the name Hieraaetus is not available for them, being a junior synonym of Aquila as the Booted Eagle is included herein.


Wedge-tailed Eagle or Eaglehawk, Aquila audax

Fossil record

Numerous fossil taxa of eagles have been described. Many have been moved to other genera, but several appear correctly assigned to this genus:

  • ?Aquila delphinensis (Middle/Late Miocene of Grive-Saint-Alban, France)
  • ?Aquila pennatoides (Middle/Late Miocene of Grive-Saint-Alban, France)
  • Aquila sp. (Late Miocene – Late Pliocene of S Europe)
  • Aquila sp. (Early Pliocene of Florida)
  • Aquila bivia (Late Pliocene of S USA)
  • Aquila sp. (Middle Pleistocene of Castiglione, Corsica)
  • ?Aquila fossilis (Middle/Late Pleistocene of Monte Reale, Sardinia)

It is not clear whether Hieraaetus” edwardsi (Middle -? Late Miocene of SW Europe) belongs into Aquila or the hawk-eagles (if the latter are indeed distinct). Its initial name, “Aquila” minuta Milne-Edwards, 1871, is preoccupied by a junior synonym of the Booted Eagle, Aquila minuta Brehm, 1831.

Not placed in Aquila anymore are:

  • “Aquila” gervaisii – now in Palaeohierax
  • “Aquila” borrasi, “A.” sodalis – now in Buteogallus. B. borrasi was long placed in Titanohierax (an extinct genus of giant hawk from Cuba and Bahamas).
  • “Aquila” pliogryps – now in Spizaetus
  • “Aquila” corroyi, “A.” depredator, “A.” hypogaea and “A.” prisca – now in Aquilavus
  • “Aquila” ferox, “A.” lydekkeri – protostrigid owls, now in Minerva.

“Aquila” danana (Snake Creek Late Miocene/Early Pliocene of Loup Fork, UEastern Imperial Eagle (Aquila heliaca)

SA), occasionally placed in Geranoaetus or Buteo, was a bird of prey of unclear relationships.

For paleosubspecies of living Aquila, see the species accounts.

Footnotes

  1. Brodkorb (1962), Mlíkovský (2002)
  2. Mlíkovský (2002): p.194Salotti et al. (2000)

References

  • Mlíkovský, Jirí (2002): Cenozoic Birds of the World, Part 1: Europe. Ninox Press, Prague. ISBN 80-901105-3-8
  • Brodkorb, Pierce (1964): Catalogue of Fossil Birds: Part 2 (Anseriformes through Galliformes). Bulletin of the Florida State Museum 8(3): 195-335. PDF or JPEG fulltext
  • Salotti, Michelle; Bellot-Gourlet, Ludovic; Courtois, Jean-Yves; Dubois, Jean-Noël; Louchart, Antoine; Mourer-Chauviré, Cécile; Oberlin, Christine; Pereira, Elisabeth; Poupeau, Gérard and Tramoni, Pascal (2000): La fin du Pléistocène supérieur et le début de l’Holocène en Corse: apports paléontologique et archéologique du site de Castiglione (Oletta, Haute-Corse) [The end of the Late Pleistocene and the Early Holocene in Corsica: New paleontological and archaeological data from Castiglione deposit (Oletta, Haute-Corse)]. Quaternaire 11: 219-230. [French with English abstract]