Rhea (bird) Rhea (bird) The rheas () 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. In addition, a feral population of the greater rhea in Germany appears
New Guinea flightless rail and diverged strongly in some aspects, while otherwise adapting in similar ways. New Guinea flightless rail The New Guinea flightless rail ("Megacrex inepta"), also known as the Papuan flightless rail, is a species of bird in the family Rallidae, in the monotypic genus "Megacrex". Sometimes however, it was included in "Amaurornis" or "Habroptila", but this is incorrect. It is found in Indonesia and Papua New Guinea. Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical mangrove forests, and subtropical or tropical swamps. It is threatened by habitat loss. "M. inepta" is indeed closely related to "Amaurornis",