Short-toed snake eagle

The short-toed snake eagle (Circaetus gallicus), also known as the short-toed eagle, is a medium-sized bird of prey in the family Accipitridae, which also includes many other diurnal raptors such as kites, buzzards and harriers. The genus name Circaetus is from the Ancient Greek kirkos, a type of hawk, and aetos, "eagle". The specific gallicus means "of Gallia".[2]

Short-toed snake eagle
In flight with prey - Trentino-South-Tyrol, Italy
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Class: Aves
Order: Accipitriformes
Family: Accipitridae
Genus: Circaetus
Species:
C. gallicus
Binomial name
Circaetus gallicus
(Gmelin, JF, 1788)
Subspecies
  • C. g. gallicus - (Gmelin, JF, 1788)
  • C. g. sacerdotis - Ng, N, Christidis, Olsen, Norman & Rheindt, 2017
Range of C. gallicus
  Breeding
  Resident
  Passage
  Non-breeding

Taxonomy

The short-toed snake 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 falcons, eagles and their relatives in the genus Falco and coined the binomial name Falco gallicus.[3] Gmelin based his description on the "Jean le Blanc" that had been described by the English ornithologist John Latham and the French ornithologists Mathurin Jacques Brisson and the Comte de Buffon.[4][5][6][7] The short-toed snake eagle is now placed in the genus Circaetus that was introduced in 1816 by the French ornithologist Louis Jean Pierre Vieillot.[8][9] The genus name is from the Ancient Greek kirkos, a type of hawk, and aetos, "eagle". The specific epithet gallicus is Latin for "Gaul" ie France.[10]

Two subspecies are recognised:[9]

  • C. g. gallicus (Gmelin, JF, 1788) – southwest Europe to central Asia, northwest China and India
  • C. g. sacerdotis Ng, NSR, Christidis, Olsen, Norman & Rheindt, 2017 – east Java, Bali, and Lombok to Timor (Lesser Sunda Islands)[11]

Description

These are relatively large snake eagles. Adults are 59 to 70 cm (23 to 28 in) long with a 162 to 195 cm (5 ft 4 in to 6 ft 5 in) wingspan and weigh 1.2–2.3 kg (2.6–5.1 lb), an average weight for the species is about 1.7 kg (3.7 lb).[12][13][14] They can be recognised in the field by their predominantly white underside, the upper parts being greyish brown. The chin, throat and upper breast are a pale, earthy brown. The tail has 3 or 4 bars. Additional indications are an owl-like rounded head, brightly yellow eyes and lightly barred under wing.

The short-toed snake eagle spends more time on the wing than do most members of its genus. It favours soaring over hill slopes and hilltops on updraughts, and it does much of its hunting from this position at heights of up to 500 m (1,600 ft). When quartering open country it frequently hovers like a kestrel.[15] When it soars it does so on flattish wings.

Distribution and habitat

This is an Old World species found throughout the Mediterranean basin, into Russia and the Middle East, and parts of Western Asia, and in the Indian Subcontinent and also further east in some Indonesian islands.

Those present on the northern edge of the Mediterranean and other parts of Europe migrate mainly to sub-Saharan Africa north of the equator, leaving in September/October and returning in April/May.[16] In the Middle and Far East the populations are resident. In Europe, it is most numerous in Spain where it is fairly common but elsewhere it is rare in many parts of its range. A bird on the Isles of Scilly, Britain, in October 1999 was the first confirmed record for that country.

The short-toed snake eagle is found in open cultivated plains, arid stony deciduous scrub areas and foothills and semi-desert areas.[17] It requires trees for nesting and open habitats, such as cultivations and grasslands for foraging.[18]

Behaviour

Its prey is mostly reptiles, mainly snakes, but also some lizards.[19] Sometimes they become entangled with larger snakes and battle on the ground.[20] Occasionally, they prey on small mammals up to the size of a rabbit, and rarely birds and large insects.

This eagle is generally very silent. On occasions, it emits a variety of musical whistling notes. When breeding, it lays only one egg. It can live up to 17 years.

The short-toed snake eagle has suffered a steep decline in numbers and range in Europe and is now rare and still decreasing in several countries due to changes in agriculture and land use. It needs protection. In the middle and far eastern part of its range, this species is not yet threatened.

Historical material

In his description of the species, Buffon says that he kept one of these eagles in captivity and observed its behavior. The captive bird ate mice and frogs, and he states that the Jean-de-blanc was well known by French farmers for raiding poultry.[21]

  • Characteristic white underside
    Characteristic white underside
  • In Kawal Wildlife Sanctuary, India
    In Kawal Wildlife Sanctuary, India
  • Swallowing prey while flying
    Swallowing prey while flying
  • Yellow eyes
    Yellow eyes
  • Detail of the feathers
    Detail of the feathers
  • With a rat
    With a rat
  • Hovering
  • Short-toed snake eagle in its nest, Rollapadu wildlife sanctuary, Andhra Pradesh, India
    Short-toed snake eagle in its nest, Rollapadu wildlife sanctuary, Andhra Pradesh, India
  • The short toes that give the name
    The short toes that give the name
  • In flight in Kuwait
    In flight in Kuwait
  • Egg, Collection Museum Wiesbaden
    Egg, Collection Museum Wiesbaden
  • Short-toed snake eagle. Saswad,Pune,India.
    Short-toed snake eagle. Saswad,Pune,India.

References
  1. BirdLife International (2016). "Circaetus gallicus". IUCN Red List of Threatened Species. 2016: e.T22734216A95078150. doi:10.2305/IUCN.UK.2016-3.RLTS.T22734216A95078150.en. Retrieved 12 November 2021.
  2. Jobling, James A. (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp. 108, 170. ISBN 978-1-4081-2501-4.
  3. Gmelin, Johann Friedrich (1788). Systema naturae per regna tria naturae : secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis (in Latin). Vol. 1, Part 1 (13th ed.). Lipsiae [Leipzig]: Georg. Emanuel. Beer. p. 259.
  4. Latham, John (1785). A General Synopsis of Birds. Vol. 1, Part 1. London: Printed for Leigh and Sotheby. p. 39, No. 17.
  5. Brisson, Mathurin Jacques (1760). Ornithologie, ou, Méthode Contenant la Division des Oiseaux en Ordres, Sections, Genres, Especes & leurs Variétés (in French and Latin). Vol. 1. Paris: Jean-Baptiste Bauche. p. 443. The two stars (**) at the start of the section indicates that Brisson based his description on the examination of a specimen.
  6. Buffon, Georges-Louis Leclerc de (1770). "Jean-Le-Blanc". Histoire Naturelle des Oiseaux (in French). Vol. 1. Paris: De l'Imprimerie Royale. p. 124; Plate 4.
  7. Buffon, Georges-Louis Leclerc de; Martinet, François-Nicolas; Daubenton, Edme-Louis; Daubenton, Louis-Jean-Marie (1765–1783). "Le Jean-le-Blanc". Planches Enluminées D'Histoire Naturelle. Vol. 5. Paris: De L'Imprimerie Royale. Plate 413.
  8. Vieillot, Louis Jean Pierre (1816). Analyse d'une Nouvelle Ornithologie Élémentaire (in French). Paris: Deterville/self. p. 23.
  9. Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (August 2022). "Hoatzin, New World vultures, Secretarybird, raptors". IOC World Bird List Version 12.2. International Ornithologists' Union. Retrieved 4 December 2022.
  10. Jobling, James A. (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. p. 108, 170. ISBN 978-1-4081-2501-4.
  11. Ng, N.S.R.; Christidis, L.; Olsen, J.; Norman, J.; Rheindt, F.E. (2017). "A new subspecies of Short-toed Snake-eagle from Wallacea determined from morphological and DNA comparison". Zootaxa. 4358 (2): 365–374. doi:10.11646/zootaxa.4358.2.9.
  12. del Hoyo, J.; Elliott, A.; Sargatal, J., eds. (1994). Handbook of the Birds of the World. Vol. 2: New World Vultures to Guineafowl. Barcelona: Lynx Edicions.
  13. Borrow, N. (2020). Field Guide to Birds of Western Africa. Bloomsbury Publishing.
  14. Klem, D. (1997). A field guide to birds of Armenia. American University of Armenia.
  15. Bakaloudis, D.E. (2010). "Hunting strategies and foraging performance of the short-toed eagle in the Dadia-Lefkimi-Soufli National Park, north-east Greece". Journal of Zoology. 281: 168–174. doi:10.1111/j.1469-7998.2010.00691.x.
  16. Bakaloudis, D.E.; C. Vlachos; G. Holloway (2005). "Nest spacing and breeding performance in Short-toed Eagle Circaetus gallicus in northeast Greece". Bird Study. 52 (3): 330–338. doi:10.1080/00063650509461407.
  17. Bakaloudis, D.E.; C. Vlachos; G.J. Holloway (1998). "Habitat use by short-toed eagles Circaetus gallicus and their reptilian prey during the breeding season in Dadia Forest (north-eastern Greece)". Journal of Applied Ecology. 35 (6): 821–828. doi:10.1111/j.1365-2664.1998.tb00001.x.
  18. Bakaloudis, D.E. (2009). "Implications for conservation of foraging sites selected by Short-toed Eagles (Circaetus gallicus) in Greece". Ornis Fennica. 86: 89–96.
  19. Bakaloudis D.E.; C.G. Vlachos (2011). "Feeding habits and provisioning rate of breeding short-toed eagles Circaetus gallicus in northeastern Greece". Journal of Biological Research. 16: 166–176.
  20. Jerdon, T.C. (1862). The Birds of India. Vol. 1. Military Orphan Press. p. 77.
  21. "The White John". The natural history of birds from the French of the Count de Buffon. Vol. 1. Translated by Anonymous. London. 1793. pp. 86–95.
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