Flightless Birds - Why Don't Birds Fly?

A-Z List of Flightless Bird Species

Southern Cassowary
Photo © thinboyfatter/Flickr/CC by 2.0

The concept of flight is intimately connected to birds, but not all birds fly. Instead, some birds develop other ways to get around and no longer need their wings, and those flightless birds fascinate birders and non-birders alike.

Why Be Flightless?

Birds fly to find food, reach a different seasonal range, escape predators and impress mates, so why would any bird species give up the ability to fly?

In areas where birds have no natural predators, rely on food sources such as fruits or fish, have no need to migrate and use other adaptations for protection and courtship, flying is much less critical.

Flightless birds still have wings, but their wings are typically smaller or less fully developed than birds that fly. The feather shapes may be different, such as looking fluffy like fur or being tiny and compact for insulation while swimming. Birds that don't fly usually have fewer wing bones or the bones may be fused together, making the wings much less mobile than is needed for flying. Most flightless birds are missing the keel of the breastbone, the part of the bone that attaches to flight muscles.

To compensate for not having wings, these birds often develop better plumage camouflage, stronger legs for running, specialized feet for swimming or other adaptations that help them survive on the ground in their native habitat.

Their wings may also develop for different uses, such as streamlining into flippers for swimming, helping provide balance or acting as brakes or rudders for swift runners. Some flightless birds, such as the kakapo and kiwi, have even evolved strong odors that may deter predators or help attract mates.

Flightless birds are found throughout the world, though the largest concentration of flightless species is in New Zealand. Until the arrival of humans on the islands of New Zealand roughly 1,000 years ago, there were no large land predators in the region. That lack of predation, plus the region's diverse habitats and rich ecosystems, was ideal for the evolution of flightless birds.

Dangers of Being Flightless

Flightless birds face many threats that can be more dangerous to them than to flying birds. Invasive predators such as cats and rats can stalk flightless birds more effectively, including invading nests. Birds that don't fly are more susceptible to poaching, traps and other man-made threats such as litter, pollution or fishing line. Because they cannot fly to a new range, habitat loss is also a critical threat to non-flying birds.

Today, more than 50 percent of flightless bird species are considered threatened or vulnerable, an additional 20 percent are endangered and one is even extinct in the wild. In total, then, more than 80 percent of these birds have a grave and uncertain future. Many flightless birds have already gone extinct, such as the moa, New Zealand goose, Jamaican ibis, Hawaiian rail, great auk, dodo and dozens of others.

Strong conservation measures are necessary to help protect the remaining numbers of these unique species.

List of Flightless Birds

There are approximately 57 flightless bird species, though the exact count can differ depending on subspecies and split classifications. While many people can name at least a few species, the different types of flightless birds are often a surprise.

* - Listed as threatened or vulnerable due to declining populations and increasing survival threats
** - Listed as endangered and in critical danger of extinction if conservation is not implemented

Threatened and endangered designations as indicated by BirdLife International.

Ratites

  • Common Ostrich (Struthio camelus)
  • Emu (Dromaius novaehollandiae)
  • *Dwarf Cassowary (Casuarius bennetti)
  • *Northern Cassowary (Casuarius unappendiculatus)
  • *Southern Cassowary (Casuarius casuarius)
  • *Great Spotted Kiwi (Apteryx haastii)
  • *Little Spotted Kiwi (Apteryx owenii)
  • **Northern Brown Kiwi (Apteryx mantelli)
  • *Southern Brown Kiwi (Apteryx australis)
  • *Greater Rhea (Rhea americana)
  • *Lesser Rhea (Rhea pennata)

Waterfowl

  • *Auckland Islands Teal (Anas aucklandica)
  • **Campbell Teal (Anas nesiotis)
  • Falkland Steamerduck (Tachyeres brachypterus)
  • Flightless Steamerduck (Tachyeres pteneres)
  • *White-headed Steamerduck (Tachyeres leucocephalus)

Grebes

  • **Junin Grebe (Podiceps taczanowskii)
  • **Titicaca Grebe (Rollandia microptera)

Cormorants

  • *Flightless Cormorant (Phalacrocorax harrisi)

Penguins

All penguins are flightless. See the complete list of penguin species for full names and threatened or endangered status, as well as more information about these unique birds.

Rails

  • *Calayan Rail (Gallirallus calayanensis)
  • Giant Coot (Fulica gigantea) (adults only; immature birds can fly)
  • *Gough Moorhen (Gallinula nesiotis)
  • **Guam Rail (Gallirallus owstoni) – Extinct in the Wild
  • *Henderson Crake (Porzana atra)
  • *Inaccessible Rail (Atlantisia rogersi)
  • *Invisible Rail (Habroptila wallacii)
  • **Lord Howe Woodhen (Gallirallus sylvestris)
  • **Makira Moorhen (Gallinula silvestris)
  • *New Britain Rail (Gallirallus insignis)
  • **New Caledonian Rail (Gallirallus lafresnayanus)
  • *New Guinea Flightless Rail (Megacrex inepta)
  • **Okinawa Rail (Gallirallus okinawae)
  • *Roviana Rail (Gallirallus rovianae)
  • **Samoan Moorhen (Gallinula pacifica)
  • *Snoring Rail (Aramidopsis plateni)
  • **Takahe (Porphyrio hochstetteri)
  • Tasmanian Native-hen (Gallinula mortierii)
  • *Weka (Gallirallus australis)
  • *Woodford's Rail (Nesoclopeus woodfordi)

Parrots

  • **Kakapo (Strigops habroptila)

A Note About Domestic Birds

Many domestic birds such as turkeys, ducks and chickens have been bred to be flightless to make it easier to raise them for agricultural purposes. Alternatively, they may have their wings clipped as a control measure to keep them from flying while in captivity, just like pet birds may have their wings clipped. Their wild ancestors, however – the wild turkey, mallard and red junglefowl – are all accomplished fliers.

Because domestic species are not counted among the roughly 10,000 species of birds in the world, and because their lack of flying ability is through artificial means, these birds are not considered truly flightless.

Flightless birds are intriguing, unique bird species that deserve – and demand – great protection to preserve their existence. Birders who can appreciate the plight of these birds can take steps to help conservation efforts take flight to keep these birds thriving on the ground.