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
Emu-wren of the smallest, the rufous-crowned, to 7.5 g of the southern emu-wren. The three species of emu-wrens each live in distinct habitats: the southern emu-wren preferring marshes and heathland, the mallee emu-wren inhabiting spinifex understory in mallee woodland, and the rufous-crowned emu-wren dwelling in spinifex in desert areas. Emu-wrens are fairly secretive and hard to spot, living in low shrub cover. They are predominantly insectivorous, but supplement their diet with seeds. Their furtive behaviour and brown colour has resulted in them being mistaken for bush mice. Emu-wren The emu-wrens ("Stipiturus") are a genus of passerine birds in the Australasian wren