Common ostrich other members of Palaeognathae and thus the flighted tinamous are the sister group to the extinct moa. It is distinctive in its appearance, with a long neck and legs, and can run for a long time at a speed of or even up to about , the fastest land speed of any bird. The common ostrich is the largest living species of bird and lays the largest eggs of any living bird (extinct elephant birds of Madagascar and the giant moa of New Zealand laid larger eggs). The common ostrich's diet consists mainly of plant matter, though it also eats
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