Flightless bird also included here. 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
Birds of New Zealand hedgehogs, and Australian possums also put pressure upon native bird species. The flightless birds were especially sensitive. Consequently, many bird species became extinct, and others remain critically endangered. Several species are now confined only to offshore islands, or to fenced "ecological islands" from which predators have been eliminated. New Zealand is today a world leader in the techniques required to bring severely endangered species back from the brink of extinction. Many bird species were introduced during the early years of European settlement to control insects as New Zealand birds species generally preferred a native bush habitat rather than the open