Don't want to see ads? Sign up...





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

 Request change
Filters

Records from Villa de Merlo

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




Loading map...




Last published photographs

Foto
Photography ID: 509527
  Adult

Villa de Merlo
San Luis
Argentina
09/03/2022
Diego Alfonso Rosa
Foto
Photography ID: 464532
 
Villa de Merlo
San Luis
Argentina
09/04/2021
Elsa Longo
Foto
Photography ID: 455459
  Adult

Villa de Merlo
San Luis
Argentina
07/10/2021
Andrés Cecconi
Foto
Photography ID: 377208
  Juvenile

Villa de Merlo
San Luis
Argentina
01/02/2020
Silvio Montani
Foto
Photography ID: 329640
  Adult

Villa de Merlo
San Luis
Argentina
04/20/2019
Rodolfo Capdevielle
Foto
Photography ID: 104196
  Juvenile

Villa de Merlo
San Luis
Argentina
06/23/2015
Dolores Fernandez
Foto
Photography ID: 100492
  Adult

Villa de Merlo
San Luis
Argentina
10/13/2013
Fernando Rodriguez
Foto
Photography ID: 51414
  Adult

Villa de Merlo
San Luis
Argentina
03/04/2014
Guillermo Marcaida



 View all photographs of the species




 Add a photography of this species





Last Vocalizations published




 Add an audio of this species





Last Filmings published


Video ID: 1664
  Juvenile

Villa de Merlo
San Luis
Argentina
06/23/2016
Claudia Mora



 Ver todos los videos de la especie




 Add a film of this species





 Reports


 Detail of places sorted by number of records








Page 1
Record IDDateExact timeCountryProvince / departmentPlaceFilmedPhotographedRecorded vocalObservedHeardWounded or deadNumber of individualsUser or BibliographyDetail
204950109/06/2024ArgentinaSan LuisMirador de los condores, Villa de Merlo3Pablo Moreno
176350310/05/2023ArgentinaSan LuisEl Filo, Villa de MerloDolores Fernandez
164842603/09/2022ArgentinaSan LuisMirador de los condores, Villa de MerloDiego Alfonso Rosa
147011104/09/2021ArgentinaSan LuisEl Filo, Villa de MerloGuillermo Marcaida
146893704/09/2021ArgentinaSan LuisEl Filo, Villa de MerloElsa Longo
143918610/07/2021ArgentinaSan LuisFilo serrano, Villa de MerloAndrés Cecconi
117732702/01/2020ArgentinaSan LuisMerlo y alrededores, Villa de MerloSilvio Montani
113322711/11/2019ArgentinaSan LuisCamino al filo y arriba alrededores de la confiteria, Villa de MerloJorgelina Lopez
113321411/11/2019ArgentinaSan LuisCamino al filo y arriba alrededores de la confiteria, Villa de MerloHernán Tolosa
114717129/07/2019ArgentinaSan LuisPasos malos, Villa de Merlo1Pablo Meoniz
Page 1

 Add a record of this species

Citation recommended:

EcoRegistros. 2026. Variable Hawk (Geranoaetus polyosoma) - Species sheet. Acceded from https://www.ecoregistros.org on 11/03/2026.