The black-and-chestnut eagle, also known as Isidor's eagle, is a large South American species of bird of prey in the family Accipitridae. It is often placed in the monotypic genus Oroaetus. However, recent genetic testing indicates that this species is fairly closely related to Spizaetus species and thus the species should be included in that genus. The black-and-chestnut eagle is a typical forest raptor, hunting primarily small to medium-sized mammals and birds and constructing a large nest in a tall tree. Unfortunately, the twin causes of habitat destruction and persecution, justified or not as an occasional poultry killer, have caused strong population declines and the black-and-chestnut eagle is considered to be an Endangered species by the IUCN.
Region
Andes Mountains
Typical Environment
Found discontinuously from the Venezuelan and Colombian Andes south through Ecuador and Peru to Bolivia in humid montane cloud forests. It favors steep slopes, ravines, and ridgelines with tall emergent trees for nesting. The species uses forest interiors but also hunts along edges, clearings, and over adjacent valleys. Large territories and high canopy cover are important for breeding and foraging.
Altitude Range
800–3000 m
Climate Zone
Highland
Ease of Keeping
Beginner friendly: 1/5
Also called Isidor's eagle, this is one of the largest forest raptors of the Andes and is sometimes placed in the monotypic genus Oroaetus. It requires extensive tracts of mature cloud forest and has a very slow breeding cycle, making it especially vulnerable to habitat loss. Persecution can occur where it occasionally preys on poultry, though its natural diet is mainly wild mammals and birds. Its presence is a strong indicator of intact montane forest ecosystems.
A 19th century painting of an adult black-and-chestnut eagle.
Close-up of an adult's face and back.
A black-and-chestnut eagle in habitat.
An adult bird in flight
Temperament
solitary and territorial
Flight Pattern
soaring glider with powerful, deep wingbeats; frequently soars over ridges and forest canyons
Social Behavior
Typically occurs as solitary adults or territorial pairs that maintain large home ranges. Monogamous pairs build large stick nests high in emergent trees and may reuse them for multiple seasons. The breeding cycle is prolonged, with extended parental care and low productivity.
Migratory Pattern
Resident
Song Description
Vocal near the nest and during territorial displays, giving sharp, piping whistles and high-pitched screams. Calls carry across valleys and are often given during soaring. Generally quiet away from breeding sites.
Plumage
Adult with glossy black head, back, and upperwings, contrasting rich chestnut underparts and underwing coverts; tail broadly banded gray and black with a whitish tip. Juveniles are much paler with whitish underparts and buffy to rufous tones and heavier tail barring. Broad wings and relatively long tail; often shows a short, bushy crest.
Diet
Apex forest raptor preying primarily on small to medium mammals such as squirrels, coatis, agoutis, and occasionally monkeys and opossums. Also takes large birds including guans, curassows, and chachalacas, and less often reptiles. Hunts by soaring along ridges or using concealed perches to launch swift ambushes through or above the canopy.
Preferred Environment
Forages in mature montane forest, along forest edges, and over narrow clearings and ravines where prey movement is concentrated. Frequently patrols ridgelines and canopy gaps that provide lift and vantage points.
