Animal Database
Nandu Rhea americana Tierpark Hellabrunn-1.jpg
Scientific Classification
Kingdom Animalia

The rheas (/ˈriːə/) are large ratites (flightless birds without a keel on their sternum bone) in the order Rheiformes, native to South America, distantly related to the ostrich and emu. Most taxonomic authorities recognize two extant species: the greater or American rhea (Rhea americana) and the lesser or Darwin's rhea (Rhea pennata). The IUCN lists the puna rhea (Rhea tarapacensis) as a separate species. The IUCN currently rates the greater and puna rheas as near-threatened in their native ranges, while Darwin's rhea is of least concern.