The booted eagle (Hieraaetus pennatus) 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.

Taxonomy

The booted eagle was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the eagle, falcons and relatives in the genus Falco and coined the binomial name Falco pennatus. Gmelin based his description on "Le Faucon Patu" or "Falco pedibus pennatis" that had been described and illustrated in 1760 by the French zoologist Mathurin Jacques Brisson. Brisson had examined a specimen in the collection of Madame de Bandeville who was also known as Marie Anne Catherine Bigot de Graveron (1709-1787). The booted eagle is now placed in the genus Hieraaetus that was introduced in 1844 by the German naturalist Johann Jakob Kaup. The genus name combines the Ancient Greek hierax meaning "hawk" with aetos meaning "eagle". The specific epithet pennatus is Latin and means "feathered". The booted eagle has no recognised subspecies. or all and most reference lists currently use H. pennata.

Although some authors name a number of subspecies most now treat it as a monotypic species.

Aquila minut described by Brehm (1831) is this bird. The fossil bird described under the same name by Milne-Edwards (1871) is preliminarily known as Hieraaetus edwardsi, but might belong in Aquila.

Description

thumb|upright|Light morph from below

thumb|Showing the white marking on the wings termed as "landing lights"

The booted eagle is a small eagle, comparable to the common buzzard in size though more eagle-like in shape. Males grow to about in weight, with females about with a length of 40 cm and a wingspan of 110–132 cm. There are two relatively distinct plumage forms. Pale birds are mainly light grey with a darker head and flight feathers. The other form has mid-brown plumage with dark grey flight feathers. It was found in a study investigating polymorphism that these discrete colour morphs follow a Mendelian inheritance pattern, where the paler allele is dominant. In South Africa, 20% of the population is the dark colour morph. However, the study found that the darker morphs are much more common in the eastern populations such as in Russia.

The call is a shrill kli-kli-kli.

The northern populations are migratory spending November to February

Southern African populations

It is believed that there may be three separate groups of booted eagles in Southern Africa. This bird is most common in the low stature shrublands of the Fynbos and Karoo, and more specifically the ecotone between the two biomes. Similarly to populations further North and South, it was most likely for clutches to consist of two eggs (67.6%).

Further reading

  • Booted Eagle species text in The Atlas of Southern African Birds
  • Booted eagle Photos at Oiseaux.net
  • Ageing and sexing (PDF; 4.2 MB) by Javier Blasco-Zumeta & Gerd-Michael Heinze
  • Booted Eagle from Nagpur, India, photo by Anuj Kale
  • Booted Eagle on the Global Raptor Information Network
  • Booted eagle Structured guide to the species in southern Africa