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
Tropical boubou more than a dozen meters up in a tree top; typically, however, it is built around 3 m in a bush, a horizontal branch fork, or in vines. Nesting sites are often solitary bushes, which provide cover while allowing the incubating bird to observe the surrounding terrain for threats. The female lays three, sometimes two eggs, which are bluish to buff green with brown and lilac spots and measure around 22–27 by 17–19 mm, or about 25 by 18.3 mm on average. Both parents incubate, but the female does most of the work. The eggs hatch after 14–16 days, and