Widespread deforestation caused limited nesting options and vulnerability to poaching for pet trade.
The Chaco Eagle, previously called Crowned Eagle, can be found in open marshland and woodland of central and eastern South America. Adults can grow up to 3 kg in weight and 80 cm in length with a wingspan of up to 185 cm.
This grey-coloured bird of prey is believed to be crepuscular (active in twilight) in nature with very sluggish movements during daytime. A single egg is produced every reproductive cycle, usually in October, and it requires a big nesting site on treetops to accommodate the size which can span up to 4 feet across and 30 cm deep.
As an apex predator, its carnivorous diet consists of monkeys, snakes, lambs, skunks, armadillos, rodents, and other birds. Its whistle is high pitched and powerful but rather melancholic.