Greater Rhea

The greater rhea is the largest native bird in the Americas, a flightless grey-brown runner with a long neck, long strong legs and a small head and bill. Its plumage looks loose and shaggy, and the long, floppy wings, which it uses for balance when running and in courtship display, cover the body; there is no tail. It has three forward-facing toes. Males are generally larger and darker than females. White leucistic birds occur in the wild. Chicks are grey with dark stripes along the body (Wikipedia, general species account).

Rheas are silent except in the breeding season, when males give a deep, booming call. Outside the breeding season they form flocks of 10–100 birds. They have great stamina and, when chased, run in a zigzag, raising one wing and then the other. They eat mostly leaves, seeds and fruit, but also catch insects and small animals. Pumas are their main natural predator, and jaguars hunt them opportunistically in the Paraguayan Chaco, central Bolivia and the Brazilian cerrado (Wikipedia, general species account).

In Bolivia the greater rhea, or ñandú, is a lowland bird that seldom goes above 1,200m; the lesser rhea of the high altiplano is a different species. On this guide the greater rhea is a target species of Kaa-Iya del Gran Chaco National Park.