A big, grey, slightly shaggy-looking raptor that rules some of South America’s most open, thorny landscapes. It has mostly dull, silvery-grey plumage, with a short black tail showing a bold white band across the middle and a white tip. Its legs and cere (the skin above the beak) are bright yellow, and on top of the head, it wears a darker grey crest that can be raised into a loose “crown,” giving the bird its name. Juveniles look quite different: they’re creamy on the head and underparts with grey streaks and a dark brown crest, so a young bird perched on a fence post looks almost like a different species from the solid grey adult.

Unlike many big eagles that haunt dense forests or mountains, the Chaco eagle is a bird of semi-open country. It lives in eastern and central South America, scattered across southern and central Brazil, Bolivia, Paraguay and Argentina south to northern Patagonia, with Uruguay probably now losing its last birds. Its favourite haunts are open woodlands, savannas, scrubby Chaco, dry grasslands and marshy areas with scattered tall trees. Those tall trees are crucial: the eagle uses them as lookout perches and nesting sites.

It often hunts by still-hunting from a perch, scanning the ground below before gliding down on prey. Its menu is heavy on small and medium mammals, especially armadillos (like pichis and nine-banded armadillos) and skunks, but also rodents, possums, hares, and even the occasional carcass or roadkill. Reptiles like snakes and large lizards are also eaten; observers have seen Chaco eagles carefully grab tegus by the hips and head to avoid being bitten or whipped by their tails, and remove snake heads before eating the rest—serious, methodical hunters rather than impulsive grab-and-go predators.

Distribution

Country

Population est.

Status

Year

Comments

Argentina

2024

Bolivia

2024

Brazil

2024

Paraguay

2024