Animalia > Chordata > Aves > Accipitriformes > Accipitridae > Buteo > Buteo polyosoma

Buteo polyosoma (Variable Hawk)

Wikipedia Abstract

The variable hawk (Geranoaetus polyosoma) is a polymorphic species of bird of prey in the Accipitridae family. It is widespread and often common in open habitats in western and southern South America, including the Falkland Islands. Its taxonomy is disputed, with some splitting it into the widespread red-backed hawk (G. polyosoma) and the Puna hawk or Gurney's hawk (G. poecilochrous) of the central and north Andean highlands, but the differences between the two are unclear. Most recent authorities have supported the lumping together of the two hawks although the issue still is controversial. On the contrary, the rare taxon from the Juan Fernández Islands is relatively distinctive, and possibly worthy of species recognition as the Juan Fernández hawk (B. exsul). In this article and most cur
View Wikipedia Record: Buteo polyosoma


EDGE Analysis

Uniqueness Scale: Similiar (0) 
 Unique (100)
Uniqueness & Vulnerability Scale: Similiar & Secure (0) 
 Unique & Vulnerable (100)
ED Score: 5.21995
EDGE Score: 1.82776


Adult Weight [1]  2.094 lbs (950 g)
Male Weight [4]  1.534 lbs (696 g)
Diet [2]  Carnivore (Vertebrates)
Diet - Endothermic [2]  100 %
Forages - Ground [2]  100 %
Clutch Size [3]  2
Wing Span [1]  4.067 feet (1.24 m)


Protected Areas

Biodiversity Hotspots

Name Location Endemic Species Website
Chilean Winter Rainfall-Valdivian Forests Chile No
Tropical Andes Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela No
Tumbes-Choco-Magdalena Colombia, Ecuador, Panama, Peru No

Prey / Diet

Prey / Diet Overlap

Institutions (Zoos, etc.)

Institution Infraspecies / Breed 
Disney's Animal Kingdom
Jardin Zoologico de Cdad.Buenos Aires
Parque Zoologico Huachipa
The Hawk Conservancy
Zagreb Zoo / Zooloski vrt Zagreb

Range Map


External References



Attributes / relations provided by
1On the allometry of wings, Enrique Morgado, Bruno Günther and Urcesino Gonzalez, Revista Chilena de Historia Natural 60: 71-79, 1987
2Hamish Wilman, Jonathan Belmaker, Jennifer Simpson, Carolina de la Rosa, Marcelo M. Rivadeneira, and Walter Jetz. 2014. EltonTraits 1.0: Species-level foraging attributes of the world's birds and mammals. Ecology 95:2027
3Jetz W, Sekercioglu CH, Böhning-Gaese K (2008) The Worldwide Variation in Avian Clutch Size across Species and Space PLoS Biol 6(12): e303. doi:10.1371/journal.pbio.0060303
4Cabot J and de Vries T (2003) Buteo polyosoma and Buteo poecilochrous are two distinct species. Bulletin of the British Ornithologists' Club 123:190-207
5Predation upon small mammals in shrublands and grasslands of southern South America: ecological correlates and presumable consequences, Fabian M. Jaksic, Revista Chilena de Historia Natural 59: 209-221 (1986)
6Population growth and density, diet and breeding success of striated caracaras Phalcoboenus australis on New Island, Falkland Islands, Paulo Catry, Miguel Lecoq, Ian J. Strange, Polar Biology Volume 31, Number 10, 1167-1174
7Ctenomys talarum, Enrique R. Justo, Luciano J. M. De Santis, and Marta S. Kin, MAMMALIAN SPECIES No. 730, pp. 1–5 (2003)
8Microcavia australis, Marcelo F. Tognelli, Claudia M. Campos, and Ricardo A. Ojeda, MAMMALIAN SPECIES No. 648, pp. 1–4 (2001)
9Jorrit H. Poelen, James D. Simons and Chris J. Mungall. (2014). Global Biotic Interactions: An open infrastructure to share and analyze species-interaction datasets. Ecological Informatics.
Ecoregions provided by World Wide Fund For Nature (WWF). WildFinder: Online database of species distributions, ver. 01.06 WWF WildFINDER
Biodiversity Hotspots provided by Critical Ecosystem Partnership Fund
Abstract provided by DBpedia licensed under a Creative Commons License