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 oil Emu oil Emu oil is an oil derived from adipose tissue harvested from certain subspecies of the emu, "Dromaius novaehollandiae", a flightless bird indigenous to Australia. Unadulterated emu oil can vary widely in color and viscosity anywhere from an off-white creamy texture to a thin yellow liquid, depending on the diet of the emu and the refining method(s) used. Industrially refined "emu grade" emu oil is composed of a minimum of 70% unsaturated fatty acids. The largest component is oleic acid, a monounsaturated omega-9 fatty acid. Emu oil also contains roughly 20% linoleic acid (an omega-6 fatty acid) and 1–2%