Despite having wings, not all birds can fly. There are several types of flightless birds, including the penguin, kiwi, moa, weka and kakapo. Kiwis for Kiwi, an independent charity that protects the kiwi populations in New Zealand, states that there are more species of flightless birds in New Zealand than in any other country.
One example of an order of flightless birds is the Struthioniformes, also known as ratites. This order includes the African ostrich, the kiwi of New Zealand, the Australian emu and several other birds that are also unable to fly. According to BeautyofBirds, the birds from this order do not have keels on their sternums to support large wing muscles, and these breast muscles are underdeveloped. Other bird orders such as the Tinamiformes also include flightless birds.