Kiwi (/ˈkiːwiː/ KEE-wee)[4] are flightless birds endemic to New Zealand of the order Apterygiformes. The five extant species fall into the family Apterygidae (/ˌæptəˈrɪdʒədiː/) and genus Apteryx (/ˈæptərɪks/).[5] Approximately the size of a domestic chicken, kiwi are the smallest ratites (which also include ostriches, emus, rheas, cassowaries  and the extinct elephant birds and moa).