Which of these birds can't fly?

The common ostrich or simply ostrich, is a species of large flightless bird native to certain large areas of Africa. It is one of two extant species of ostriches, the only living members of the genus "Struthio" in the ratite order of birds.

The common ostrich's diet consists mainly of plant matter, though it also eats invertebrates. It lives in nomadic groups of 5 to 50 birds. When threatened, the ostrich will either hide itself by lying flat against the ground, or run away. If cornered, it can attack with a kick of its powerful legs. Mating patterns differ by geographical region, but territorial males fight for a harem of two to seven females.

The common ostrich is farmed around the world, particularly for its feathers, which are decorative and are also used as feather dusters. Its skin is used for leather products and its meat is marketed commercially, with its leanness a common marketing point.