Ratites Bird Group

Ratites

Taxonomists group several orders of large flightless birds under the term ratite. The word refers to the flat, raft -like shape of the sternum, which lacks the keel shape typical of the breastbone of flying birds. Ratites include several orders: ostriches of Africa that also used to inhabit western Asia; rheas of South America; emus of Australia and cassowaries of Australia and New Guinea; New Zealand kiwis; and families such as moas and elephant birds, which are now extinct. Ornithologists generally agree that ratites evolved from flying ancestors, but they are uncertain if the different orders are closely related to each other. All ratites have powerful legs, and the open-country ostriches, rheas, and emus are excellent runners. Most species of ratites feed on a variety of plant material, although the kiwis of the forest floor use their long bills to capture earthworms and insects.