Birds That Cannot Fly: Flightless Birds Around the World

One of the most frequently asked questions in ornithology is what bird cannot fly. The answer includes a diverse group of species known as flightless birds, such as the ostrich, penguin, kiwi, emu, cassowary, and kakapo. These birds have evolved without the ability to fly due to specific environmental conditions, lack of natural predators, and adaptations for terrestrial or aquatic life. While most birds are equipped with hollow bones, strong pectoral muscles, and aerodynamic feathers for flight, flightless birds have developed alternative survival strategies—like speed, size, or swimming ability—that make flying unnecessary. Understanding what kinds of birds cannot fly offers insight into evolutionary biology, ecological niches, and conservation challenges facing these unique species today.

What Makes a Bird Flightless?

Flightlessness in birds is not a flaw but an evolutionary adaptation. Over millions of years, certain bird species lost the ability to fly because it no longer provided a survival advantage. In isolated environments—such as islands without land predators—birds that invested energy into large bodies, strong legs, or enhanced senses outcompeted those relying on flight. As a result, their wings became smaller and less functional, while their sternums (keel bones) flattened, reducing space for flight muscles.

Birds that cannot fly typically exhibit several anatomical differences from their flying relatives:

• Reduced or absent keel: The keel anchors flight muscles; flightless birds often lack this structure.
• Denser bones: Unlike flying birds with hollow bones to reduce weight, flightless species have heavier skeletons.
• Smaller wing size relative to body mass: Wings may be vestigial or repurposed (e.g., flippers in penguins).
• Enhanced leg development: Powerful legs allow for running (ostrich), swimming (penguin), or digging (kiwi).

Major Flightless Birds Around the World

There are over 60 extant species of flightless birds, distributed across various continents and ecosystems. Below is a breakdown of some of the most well-known examples:

Bird Species	Native Region	Max Speed/Adaptation	Conservation Status
Ostrich (Struthio camelus)	Africa	45 mph (70 km/h) – fastest bird on land	Near Threatened
Penguin (various species)	Antarctica, Southern Hemisphere	Swims up to 22 mph (36 km/h)	Varies by species (e.g., Emperor: Least Concern; Yellow-eyed: Endangered)
Kiwi (Apteryx spp.)	New Zealand	Nocturnal, excellent sense of smell	All species endangered
Emu (Dromaius novaehollandiae)	Australia	31 mph (50 km/h), long-distance walker	Least Concern
Cassowary (Casuaris spp.)	New Guinea, Australia	Powerful kick, forest-dwelling	Vulnerable to Endangered
Kakapo (Strigops habroptilus)	New Zealand	Heaviest parrot, nocturnal, climbs trees	Critically Endangered

The Ostrich: Master of the Open Plains

The African ostrich is the largest living bird and completely incapable of flight. Standing up to 9 feet tall and weighing over 300 pounds, its massive size makes flight impossible. Instead, it relies on powerful legs to escape predators, reaching speeds of nearly 45 miles per hour. Ostriches also use their wings for balance during sharp turns and for courtship displays. Found in savannas and arid regions, they are social birds often seen in small groups.

Penguins: Flying Through Water

While penguins cannot fly in the air, they are exceptional swimmers—essentially “flying” underwater using their flipper-like wings. All 18 species of penguins are flightless, adapted to marine environments in the Southern Hemisphere. The emperor penguin, for example, can dive deeper than 1,800 feet and hold its breath for over 20 minutes. Their dense bones help with diving, counteracting buoyancy—a trait opposite to flying birds. Climate change and overfishing pose major threats to penguin populations.

Kiwi: New Zealand’s Nocturnal Treasure

The kiwi is one of the smallest flightless birds but holds immense cultural significance in New Zealand, where it is both a national symbol and a taonga (treasure) to Māori people. With hair-like feathers, a long beak equipped with nostrils at the tip, and a keen sense of smell, the kiwi forages at night in forests. It lays one of the largest eggs relative to body size of any bird—up to 20% of the female’s weight. Habitat loss and invasive predators like stoats have driven all five kiwi species toward extinction.

Emus and Cassowaries: Australia and New Guinea’s Giants

The emu, second only to the ostrich in height, roams open woodlands and grasslands of Australia. Though flightless, it can cover vast distances on foot and swim when necessary. Emus play a key role in seed dispersal and ecosystem health.

The southern cassowary, found in tropical rainforests, is more elusive and potentially dangerous due to its powerful kick. Known as the “world’s most dangerous bird,” it defends itself with a dagger-like claw on each foot. Deforestation and vehicle strikes threaten its survival.

The Kakapo: A Parrot That Can’t Fly

The kakapo is perhaps the most unusual flightless bird—a nocturnal, ground-dwelling parrot native to New Zealand. Once widespread, it was pushed to the brink by introduced mammals like rats and cats. By the late 20th century, fewer than 50 individuals remained. Thanks to intensive conservation efforts—including relocation to predator-free islands and artificial breeding programs—the population has slowly increased to around 250 birds as of 2024. The kakapo’s mating call, a deep booming sound heard miles away, is part of a rare lek mating system.

Evolutionary Origins of Flightlessness

Flightlessness has evolved independently in multiple bird lineages, a phenomenon known as convergent evolution. On islands such as New Zealand, Madagascar, and Hawaii, birds faced few mammalian predators, allowing them to occupy ecological roles usually filled by mammals. Without pressure to escape via flight, natural selection favored traits like larger size, stronger legs, and improved foraging abilities.

However, human arrival disrupted these ecosystems. Polynesians, Europeans, and other settlers introduced dogs, rats, pigs, and cats—predators that native flightless birds had no defenses against. This led to the extinction of many species, including:

• Moa (New Zealand): Giant herbivorous birds up to 12 feet tall; hunted to extinction by Māori by the 15th century.
• Dodo (Mauritius): A plump pigeon-like bird wiped out by sailors and invasive species by the late 17th century.
• Great Auk (North Atlantic): Once abundant, it was killed for its feathers and oil; last confirmed sighting in 1844.

These extinctions highlight how vulnerable flightless birds are to rapid environmental change.

Where to See Flightless Birds in the Wild

Observing flightless birds in their natural habitats requires careful planning and respect for conservation guidelines. Here are some top destinations:

• New Zealand: Visit sanctuaries like Zealandia (Wellington) or Codfish Island to see kiwis and kakapos (permits required). Guided night tours increase chances of spotting these shy birds.
• South Africa: Oudtshoorn in the Klein Karoo region is known as the “Ostrich Capital.” Take farm tours to learn about ostrich behavior and breeding.
• Tasmania and Australia: Freycinet National Park and Kangaroo Island offer opportunities to spot emus in the wild.
• Patagonia and Antarctica: Cruise operators run eco-tours to see Magellanic, king, and emperor penguins along coastal areas.
• Papua New Guinea: Remote expeditions may allow sightings of southern cassowaries in lowland rainforests.

When visiting, always follow local regulations: maintain distance, avoid flash photography, and never feed wildlife. Supporting ecotourism helps fund conservation programs.

Common Misconceptions About Flightless Birds

Several myths persist about birds that cannot fly:

• Myth: Flightless birds are primitive or less evolved.
  Reality: They are highly specialized products of evolution, adapted perfectly to their environments.
• Myth: All flightless birds are large.
  Reality: The smallest flightless bird is the weka (about the size of a chicken), and some rails are even smaller.
• Myth: Penguins live at the North Pole.
  Reality: Penguins are native to the Southern Hemisphere; polar bears inhabit the Arctic.
• Myth: Flightlessness means helplessness.
  Reality: Many flightless birds are agile runners, swimmers, or climbers with complex behaviors.

How to Support Conservation Efforts

Many flightless birds face high risks of extinction. You can contribute to their survival through:

• Donating to conservation organizations: Groups like the Department of Conservation (New Zealand), SANCCOB (South Africa), and WWF run critical recovery programs.
• Volunteering: Some reserves accept trained volunteers for monitoring and habitat restoration.
• Responsible tourism: Choose operators committed to low-impact practices and community involvement.
• Advocacy: Raise awareness about invasive species control and habitat protection.
• Research participation: Citizen science platforms like eBird allow users to report sightings and support data collection.

Frequently Asked Questions

What bird cannot fly but runs very fast?

The ostrich is the fastest-running flightless bird, capable of sprinting at 45 mph (70 km/h), making it the fastest bird on land.

Can any penguins fly?

No, all penguin species are flightless. They use their wings as flippers to swim efficiently underwater instead of flying in the air.

Why did the dodo become extinct?

The dodo went extinct primarily due to human activity—hunting and the introduction of invasive species like rats and pigs that destroyed nests and competed for food.

Are there flightless birds outside of remote islands?

Yes, several flightless birds live on mainlands, including the ostrich (Africa), emu (Australia), and cassowary (New Guinea and Australia).

Is the kiwi bird endangered?

Yes, all five species of kiwi are classified as endangered due to predation by invasive mammals and habitat destruction.

In conclusion, understanding what bird cannot fly opens a window into evolutionary biology, ecological adaptation, and global conservation. From the towering ostrich to the secretive kiwi, flightless birds challenge our assumptions about what it means to be a bird. By learning about their lives, threats, and importance, we can better appreciate and protect these remarkable creatures for future generations.