The largest bird in South America; resembles an ostrich and is unmistakable. Flightless and appears tailless. Mostly gray-brown overall with very long legs and neck and a proportionally small head. Males have a dark brown crown and blackish lower neck and upperparts. Females have lighter plumage. Juveniles look similar to adults but are smaller. Inhabits open areas with scattered trees and shrubs, such as savannas and pampas, where it can gather in large groups. The males are responsible for incubating the eggs and looking after the chicks.