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Species icon
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: 634516
  Adult

Ruta 251
Río Negro
Argentina
05/07/2025
Juan Manuel Canepa
Foto
Photography ID: 634496
  Adult

Ruta 1
Chubut
Argentina
05/08/2025
Juan Manuel Canepa
Foto
Photography ID: 596908
  Adult

Ruta provincial 1 costera
Río Negro
Argentina
08/22/2024
Juan Manuel Canepa
Foto
Photography ID: 596880
  Adult

Ruta 25
Chubut
Argentina
08/18/2024
Juan Manuel Canepa
Foto
Photography ID: 525852
  Adult

Caviahue
Neuquén
Argentina
02/22/2023
Juan Manuel Canepa
Foto
Photography ID: 525821
  Adult

Cuesta del Rahue
Neuquén
Argentina
02/18/2023
Juan Manuel Canepa
Foto
Photography ID: 504343
  Juvenile

Puerto Madryn
Chubut
Argentina
08/12/2022
Juan Manuel Canepa
Foto
Photography ID: 504342
  Adult

Puerto Madryn
Chubut
Argentina
08/12/2022
Juan Manuel Canepa
Foto
Photography ID: 440246
  Adult

Ruta Nacional 9
Tucumán
Argentina
03/31/2021
Juan Manuel Canepa
Foto
Photography ID: 439672
  Juvenile

Raco
Tucumán
Argentina
04/04/2021
Juan Manuel Canepa
Foto
Photography ID: 439611
  Adult

Ticucho
Tucumán
Argentina
03/30/2021
Juan Manuel Canepa
Foto
Photography ID: 389757
  Adult

Quebrada del Toro
Salta
Argentina
01/25/2020
Juan Manuel Canepa



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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
228766108/05/2025ArgentinaChubutRuta 1 en el camino a Punta Tombo, Ruta 1Juan Manuel Canepa
228774807/05/2025ArgentinaRío NegroEntre Conesa y San Antonio, Ruta 251Juan Manuel Canepa
213702322/08/2024ArgentinaRío NegroProximidades Punta Bermeja, Ruta provincial 1 costeraJuan Manuel Canepa
213697918/08/2024ArgentinaChubutEntre Los Altares y Tecka, Ruta 25Juan Manuel Canepa
172842922/02/2023ArgentinaNeuquénRío Agrio, CaviahueJuan Manuel Canepa
172834818/02/2023ArgentinaNeuquénMirador de la Cuesta del Rahue, Cuesta del RahueJuan Manuel Canepa
162747612/08/2022ArgentinaChubutRuta Nac 3, Puerto MadrynJuan Manuel Canepa
162666212/08/2022ArgentinaChubutRuta Nac 3, Puerto MadrynJuan Manuel Canepa
139279404/04/2021ArgentinaTucumánRaco, RacoJuan Manuel Canepa
139280331/03/2021ArgentinaTucumánRuta Nacional 9Juan Manuel Canepa
Page 1

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Citation recommended:

EcoRegistros. 2026. Variable Hawk (Geranoaetus polyosoma) - Species sheet. Acceded from https://www.ecoregistros.org on 29/03/2026.