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
Birds of Australia tail for rapid changes of direction. In consequence, the unrelated birds that fill that role in the Americas and in Australia look and act as though they are close relatives. Australian birds which show convergent evolution with Northern Hemisphere species: Australian birds can be classified into six categories: For comprehensive regional lists, see: For Australia's endemic species, see: Other regional, state and island bird lists: National organizations Australian regional and state organisations Important regional references include: Full-coverage field guides in print are as follows, in rough order of authority: Birds of Australia Australia and its offshore islands and territories have