Either of two ostrich-like species of South American three-toed ratite birds (family Rheidae). The common rhea (Rhea americana) is about 4 ft (120 cm) tall and weighs about 50 lbs (20 kg). It has luxuriant plumage, brown or gray above and whitish below. Darwin's rhea (Pterocnemia pennata) is smaller and has white-tipped brownish plumage. Rheas live in open country, often among grazing animals, and run from predators. They eat a wide variety of plants and animals. Both species are listed as endangered.
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