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Variable Hawk

Geranoaetus polyosoma
(Quoy, JRC; Gaimard, JP, 1824)
Aguilucho Común
Gavião-de-costas-vermelhas

Family: Accipitridae
Order: Accipitriformes
Class: Aves
Phylum / Division: Chordata
Kingdom: Animalia

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Conservation status according to BirdLife International: Least Concern

Other common names: Ñanco, Aguilucho Variable.

Synonyms: Buteo polyosoma, Falco polyosoma.

Subspecies:


Description: It is a large, long-winged raptor with a slender profile and remarkable plumage variability. Individuals range from mostly ash-gray to rufous or chestnut tones, with lighter or darker underparts depending on morph. In flight, it is recognized by its slightly raised wings forming a shallow “V”, relatively short tail, and pale patches at the base of the primaries. Juveniles tend to be browner and more streaked.

Geographic distribution: It is widely distributed across South America, from southern Colombia and Venezuela to southernmost Chile and Argentina. It is especially common along the Andes, but also inhabits Patagonian steppes, intermontane valleys, and open lowlands.

Habitat: It occupies open and semi-open habitats, including grasslands, shrublands, agricultural areas, and mountainous regions. It tolerates a broad altitudinal range, from sea level to over 4,000 m, efficiently using thermal currents for soaring.

Diet: It is an opportunistic predator, feeding mainly on small mammals (particularly rodents), medium-sized birds, reptiles, and large insects. It also scavenges when opportunities arise, which increases its dietary flexibility.

Behavior: Usually seen alone or in pairs, though it may gather where food is abundant. It spends long periods soaring with a powerful yet economical flight, and maintains large territories during the breeding season.

Nesting: It builds large stick nests, typically on rocky cliffs, escarpments, or occasionally tall trees and human-made structures. Clutches usually consist of one to two eggs, with shared parental care and an extended fledging period.

Conservation status: It is classified as Least Concern globally due to its wide range and generally stable populations, although local threats include persecution, electrocution, and habitat alteration.


Author of this compilation: EcoRegistros – 15/12/2025




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Last published photographs

Foto
Photography ID: 495597
  Adult

Parque Nacional Antisana
Napo
Ecuador
05/16/2022
Carlos Schmidt
Foto
Photography ID: 163834
 
El Siambón
Tucumán
Argentina
08/16/2016
Carlos Schmidt
Foto
Photography ID: 114576
  Juvenile

Piedra del Águila
Neuquén
Argentina
09/12/2015
Carlos Schmidt
Foto
Photography ID: 114575
  Adult

Piedra del Águila
Neuquén
Argentina
09/12/2015
Carlos Schmidt
Foto
Photography ID: 114507
  Adult

Colonia 25 de Mayo
La Pampa
Argentina
09/13/2015
Carlos Schmidt
Foto
Photography ID: 71068
  Adult

Caracoles libertadores
Región de Valparaíso
Chile
12/03/2014
Carlos Schmidt
Foto
Photography ID: 53141
  Adult

Palmasola
Jujuy
Argentina
06/01/2014
Carlos Schmidt
Foto
Photography ID: 48461
  Adult

Farellones
Región Metropolitana
Chile
04/14/2014
Carlos Schmidt
Foto
Photography ID: 43898
  Adult

Reserva Natural Villavicencio
Mendoza
Argentina
03/12/2014
Carlos Schmidt
Foto
Photography ID: 40182
  Juvenile

Reserva Natural Villavicencio
Mendoza
Argentina
02/21/2014
Carlos Schmidt
Foto
Photography ID: 38433
  Adult

La Carrera
Mendoza
Argentina
02/06/2014
Carlos Schmidt



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 Reports


 Detail of places sorted by number of records








Page 1
Record IDDateExact timeCountryProvince / departmentPlaceFilmedPhotographedRecorded vocalObservedHeardWounded or deadNumber of individualsUser or BibliographyDetail
171119525/01/2023ArgentinaMendozaCamino Francisco Guiñazú (-32,986335, -69,351952)1Carlos Schmidt
159072016/05/2022EcuadorNapoParque Nacional AntisanaCarlos Schmidt
46892616/08/2016ArgentinaTucumánEl SiambónCarlos Schmidt
45341617/07/2016ArgentinaSan LuisRuta 7Carlos Schmidt
45331117/07/2016ArgentinaSan LuisEmbalse ogoli, NogolíCarlos Schmidt
44354813/06/2016ArgentinaSan LuisRuta 20 hacia Luján1Carlos Schmidt
43821925/05/2016ArgentinaMendozaCamino a La Carrera10Carlos Schmidt
43825130/04/2016ArgentinaMendozaLagunas del Rosario, Lavalle2Carlos Schmidt
43797209/04/2016ArgentinaMendozaReserva Natural Villavicencio1Carlos Schmidt
32886413/09/2015ArgentinaLa PampaColonia 25 de MayoCarlos Schmidt
Page 1

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Citation recommended:

EcoRegistros. 2026. Variable Hawk (Geranoaetus polyosoma) - Species sheet. Acceded from https://www.ecoregistros.org on 25/03/2026.