The Flightless birds are birds which lack the ability to fly, relying instead on their ability to run or swim. They are thought to have evolved from flying ancestors. There are about forty species in existence today. The best known being the Ostrich, Emu, Cassowary, Rhea, Kiwi, and Penguin.
New Zealand has more species of flightless birds; including the Kiwis, several species of Penguins, and the Takahe; than any other country.
The smallest flightless bird is the Inaccessible Island Rail [length 12.5 cm] and The largest flightless bird, which is also the largest living bird, is the Ostrich [9 ft], although some extinct species grew to larger sizes.
Flightless birds are the easiest to take care of in captivity because they do not have to be caged. Ostriches were once farmed for their decorative feathers. Today they are raised for meat and for their skins, which are used to make leather.