Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species, including the well known ratites and penguins. The smallest flightless bird is the Inaccessible Island rail. The largest flightless bird, which is also the largest living bird, is the ostrich. Ostriches are farmed for their decorative feathers, meat and their skins, which are used to make leather.
