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
Bird egg birds with small clutch size tended to be indeterminate. Many animals feed on eggs. For example, the principal predators of the black oystercatcher's eggs include raccoons, skunks, mink, river and sea otters, gulls, crows and foxes. The stoat ("Mustela erminea") and long-tailed weasel ("M. frenata") steal ducks' eggs. Snakes of the genera "Dasypeltis" and "Elachistodon" specialize in eating eggs. Humans have a long history of both eating wild bird eggs and raising birds for farmed eggs for consumption. Brood parasitism occurs in birds when one species lays its eggs in the nest of another. In some cases, the host's eggs