Black-chested Buzzard-Eagle

The Black-chested Buzzard-Eagle is one of the largest raptors of South America, occupying mountains, steppe, and open country from Colombia south to Tierra del Fuego. Despite its eagle-like bulk, it is classified as a buteonine hawk, and it is most often seen soaring on flat, broad wings high over Andean slopes and Patagonian grasslands.

Flight feathers are notably broad and pale silvery-gray on their upper surface, contrasting against darker underwing coverts, a pattern that helps distinguish this species at long range even before plumage colors are visible. The tail is unusually short and wedge- or fan-shaped for such a large raptor, with gray feathers showing little banding. Body feathers are gray above and white below, with the black feathers of the upper breast forming a sharply defined dark patch against the white underparts, unlike any smaller hawk sharing its range.

Adults are gray above and white below with a distinctive black patch across the upper breast, a combination unique among large South American raptors. Juveniles are mottled brown overall and lack the sharp gray-white-black adult pattern, taking several years to reach full adult plumage through successive molts. Sexes look similar, though females average larger.

This species occupies high Andean slopes, foothills, and open grassland and steppe country across much of South America, from the northern Andes in Colombia and Venezuela south through Chile and Argentina to Tierra del Fuego. Most populations are resident, though birds in higher elevations may shift downslope during harsher winter conditions.

A powerful soaring hunter, it takes rodents, hares, and birds, and will also feed on carrion, riding thermals for long periods over open terrain in search of prey. Nests are large stick platforms built on cliff ledges or in isolated trees, and the species gives a deep, far-carrying whistled call, most often near the nest site or during territorial soaring displays.