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 Reserva de Biósfera Ñacuñán

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




 View all photographs of the species




 Add a photography of this species





Last Vocalizations published




 Add an audio of this species





Last Filmings published





 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
171490125/01/2023ArgentinaMendozaReserva de Biósfera Ñacuñán2Pablo Bruni
161573725/07/2022ArgentinaMendozaReserva de Biósfera Ñacuñán4Pablo Moreno
156653713/05/2021ArgentinaMendozaReserva de Biósfera ÑacuñánManuel Godoy
88086825/01/2019ArgentinaMendozaReserva de Biósfera ÑacuñánRomán Montero
63986828/10/2017ArgentinaMendozaReserva de Biósfera ÑacuñánMarcelo Zanotti
59332813/07/2017ArgentinaMendozaReserva de Biósfera ÑacuñánMateo Alberto Gual
34625811/10/2015ArgentinaMendozaReserva de Biósfera ÑacuñánFederico Bruno
34571611/10/2015ArgentinaMendozaReserva de Biósfera ÑacuñánMarcelo Fabio Dolsan
34465011/10/2015ArgentinaMendozaReserva de Biósfera Ñacuñán2Mariano Costa
34373811/10/2015ArgentinaMendozaReserva de Biósfera ÑacuñánLihué Bruno
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 19/03/2026.