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
Kangaroo Island emu regarding the taxonomic status and geographic origin of the Kangaroo Island emu, particularly with respect to their relationship to the King Island emu, which were also transported to France as part of the same expedition. The expeditions logbooks failed to clearly state where and when dwarf emu individuals were collected. This led to both taxa being interpreted as a single taxon and that it originated from Kangaroo Island. More recent finds of sub-fossil material and subsequent studies on King and Kangaroo Island emu confirm their separate geographic origin and distinct morphology. In his 1907 book "Extinct Birds", Walter Rothschild claimed