The Black-and-chestnut Eagle is a very large raptor, closely allied with the similar hawk-eagles (Spizaetus) of the lowlands. This eagle is endemic to the humid montane forests of the Andes from Venezuela to Bolivia. It is a very dark species, being primarily black with a deep chestnut breast, tarsi and vent. At lower elevations, it may narrowly overlap with the lowland hawk-eagles, where it would be most easily confused with Black Hawk-Eagle, but note its chestnut underparts, larger size and distinctive tail pattern. The Black-and-chestnut Eagle feeds on large birds, such as cracids, and on arboreal mammals, ranging in size from squirrels to monkeys, especially Woolly Monkeys (Lagothrix).