Rheas

Rheas are large, flightless birds native to South America, resembling a smaller ostrich, and are known in different regions as ñandus, ema, suri, or choique. Two main species are recognized: the greater (Rhea americana) and the lesser or Darwin's rhea (Rhea pennata), with the IUCN additionally listing the puna rhea as a separate species. They are characterized by gray-brown plumage, long legs, and an ability to run swiftly with wings outstretched acting as sails; they also uniquely store urine separately in their cloacas. These birds are found across a variety of South American habitats, from grasslands to shrubland, with the greater rhea preferring regions up to 1,500 meters, and the lesser rhea higher altitudes up to 4,500 meters. Rheas have a diet mainly consisting of plants but also include insects, small reptiles, and rodents. Breeding involves a polygamous system where males incubate and protect eggs laid by multiple females. The greater and puna rheas are considered near-threatened, whereas the Darwin's rhea is of least concern. Additionally, feral populations have arisen in Germany and the UK after escapes from captivity. Rheas have cultural and practical significance in South America, being used for their feathers, skin, and meat, and historically were hunted by gauchos with bolas. Their images have also been featured on currency in Argentina and Uruguay.