Flightless bird Flightless bird Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species including the well known ratites (ostrich, emu, cassowary, rhea and kiwi) and penguins. The smallest flightless bird is the Inaccessible Island rail (length 12.5 cm, weight 34.7 g). The largest (both heaviest and tallest) flightless bird, which is also the largest living bird, is the ostrich (2.7 m, 156 kg). Ostriches are farmed for their decorative feathers, meat and their skins, which are used to make leather. Many domesticated birds, such as the domestic chicken and domestic duck, have lost
Emu Emu The emu ("Dromaius novaehollandiae") is the second-largest living bird by height, after its ratite relative, the ostrich. It is endemic to Australia where it is the largest native bird and the only extant member of the genus "Dromaius". The emu's range covers most of mainland Australia, but the Tasmanian emu and King Island emu subspecies became extinct after the European settlement of Australia in 1788. The bird is sufficiently common for it to be rated as a least-concern species by the International Union for Conservation of Nature. Emus are soft-feathered, brown, flightless birds with long necks and legs, and