(Des Murs, 1845)
Oroaetus isidori (Des Murs, 1845)
The black-and-chestnut eagle (Spizaetus isidori) is a South American species of bird of prey in the Accipitridae family. It is sometimes called Isidor's eagle. It is often placed in the monotypic genus Oroaetus.
This is a fairly large eagle at 63–74 cm (25–29 in) long with a wingspan of 147–166 cm (58–66 in). As an adult, this species is glossy black on the head and the back and a streaky chestnut on the underside, much of the wing primaries and legs. The juvenile bird is very different, being whitish over the head and body with a buffy wash underneath and scaly gray on the back and wings. Nest building is February and March, laying eggs in April and May and fledging young by August and September. It builds a huge stick nest about 2 m (6.6 ft) across and 1 m (3.3 ft) deep. Clutches include 1 to 2 fledgings. At the nest area, adults primarily bring squirrels to their young.
They are known to prey on woolly monkeys, porcupines, coatis and other mid-sized arboreal mammals. Large birds such as guans are also taken. They frequently have much abraded tails by plunging after prey through the branches. They overlap in range with several other large forest eagles, including solitary eagle and possibly other Spizaetus eagles, but no interactions have been reported and the black-and-chestnut eagle is believed to be normally the top avian predator in its range.
It is found humid montane forests, normally at elevations between 1,800-2,500 meters, in the Andes from northern Argentina, through Bolivia, Peru, Ecuador, Colombia, to Venezuela, with isolated populations in the Venezuelan Coastal Range, Serranía del Perijá and Sierra Nevada de Santa Marta. It is generally local and rare.