Rheas are either of two species of large, flightless birds endemic to South America. The two known extant species are the Greater Rhea (Rhea Americana) and the Lesser Rhea (Rhea pennata).
Resembling an ostrich, but are smaller, Rheas have gray-brown plumage, small heads with pointed beaks, long necks, rounded bodies, and powerful long legs.
These shy, but agile birds can reach 120 cm tall and weigh up to 20 kg. They are omnivorous and feed on leaves, beetles, lizards and grasshoppers.