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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: 626355
 
Ruta Provincial 1
Chubut
Argentina
03/06/2025
Susana Gomez
Foto
Photography ID: 531483
  Adult

Partido de Villarino
Buenos Aires
Argentina
01/01/2023
Susana Gomez
Foto
Photography ID: 505076
  Juvenile

Ruta 35 cerca de Bahía Blanca
Buenos Aires
Argentina
08/20/2022
Susana Gomez
Foto
Photography ID: 505075
  Juvenile

Ruta 35 cerca de Bahía Blanca
Buenos Aires
Argentina
08/20/2022
Susana Gomez
Foto
Photography ID: 484057
  Adult

Ruta 40
Neuquén
Argentina
02/01/2022
Susana Gomez
Foto
Photography ID: 453678
  Juvenile

Reta
Buenos Aires
Argentina
07/09/2021
Susana Gomez
Foto
Photography ID: 441750
  Adult

Partido de Villarino
Buenos Aires
Argentina
04/16/2021
Susana Gomez
Foto
Photography ID: 441749
  Adult

Partido de Villarino
Buenos Aires
Argentina
04/16/2021
Susana Gomez



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 Detail of places sorted by number of records








Page 1
Record IDDateExact timeCountryProvince / departmentPlaceFilmedPhotographedRecorded vocalObservedHeardWounded or deadNumber of individualsUser or BibliographyDetail
229713307/06/202513:12ArgentinaBuenos AiresVía Sin NombreSusana Gomez
225913308/03/202514:25ArgentinaBuenos AiresRuta Nacional 3 750Susana Gomez
225768807/03/202507:18ArgentinaChubutRuta Provincial 30Susana Gomez
225735606/03/202509:14ArgentinaChubutRuta Provincial 1Susana Gomez
225769905/03/202517:53ArgentinaChubutCamino sin nombrarSusana Gomez
225535003/03/202510:23ArgentinaChubutRuta Nacional 3Susana Gomez
225430728/02/202518:16ArgentinaRío NegroRuta Nacional 251 174Susana Gomez
179231110/07/2023ArgentinaLa PampaCercania del parque Provincial Pedro LuroSusana Gomez
176567014/05/2023ArgentinaBuenos AiresPuerto Ingeniero White, Bahía Blanca1Susana Gomez
174977615/04/2023ArgentinaBuenos AiresRuta Nacional 249Susana Gomez
Page 1

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Citation recommended:

EcoRegistros. 2026. Variable Hawk (Geranoaetus polyosoma) - Species sheet. Acceded from https://www.ecoregistros.org on 11/04/2026.