Birds Fly, Right? Meet 7 That Totally Can't

birds can't fly — Penguins cannot fly because they have very short wings and proportionately heavy bodies. Wang Jianwei/Xinhua/Getty Images

Ask most people what they'd want their superpower to be, and many would say they'd want to fly like a bird. But do the birds that can't fly wish that they too had the superpower to take to the skies? While we can't possibly know what's in those little bird brains of theirs, the surprisingly large number of birds that can't fly are likely quite content given that they've evolved to protect and feed themselves without the need for flight.

Roger J. Lederer, expert ornithologist, Professor Emeritus at California State University, Chico, and author of various books about birds, shares in an email interview, "There are 126 species of birds that have lost the ability to fly. In most cases they are island dwelling birds on an island with few or no large predators, so they save energy by not flying. Or they are big birds that can protect themselves." He also says that a few species of ducks live in fast flowing waters that deter predators while others are nocturnal to keep themselves safe.

How did they lose the ability to fly? For years scientists have debated the cause and examined the genes of various species to understand why. For the ratites, a group of mostly flightless, long-legged birds, the extinction of the dinosaurs changed their course. Scientists have now shown through DNA samples that these birds could at one time fly, but without dinosaurs lurking around, they had their pickings of food, allowing them to grow larger and larger and eventually able to run from predators instead of taking flight.

Other species of birds found themselves in the position of using their wings for better purposes and evolved over time. Lederer explains that some birds, like penguins, use their wings to swim, some use them to remain waterproof, and the largest ones use them for balance and/or display.

Let's take a look at seven birds that can no longer fly:

1. Ostrich

The largest living bird, the ostrich can grow to be bigger than even the largest of men, coming in at up to 9 feet tall (around 3 meters) and 300 pounds (136 kilograms). They can run up to 45 mph (75 kph), so there's not much reason to fly when you've got legs like that. Not to mention getting up in the air would be really difficult with all that weight. Lederer explains that ostriches often use their wings for balance and put them on display to attract a mate.

2. Penguin

Penguins' inability to fly creates a major cute factor that we humans just can't resist — their adorable waddle as they move their plump bodies back and forth across the ground. None of the 18 species of penguins can fly, but their wings are still put to good use as flippers that help them swim quickly and avoid predators when they go hunting for fish.

3. Kiwi

Despite being shy and nocturnal, these birds have managed to become pretty iconic. Kiwis are the national bird of New Zealand and, of course, the namesake for a uniquely brown and green fuzzy little fruit. They're also quite unique. Kiwi's don't nest, rather they burrow into the ground. Whisker-like feathers surround their long beaks that even have nostrils at the end to help them navigate in the dark. They don't have a tail, and while it appears they don't have wings, they're actually just so small — only 1 inch (3 centimeters) long — that they're hidden under all their feathers and are no help for flying.

4. Cassowary

The cassowary's black, hair-like feathers, colorful wattle and "helmet" on top of its head draw our curiosity, but this is one bird you definitely don't want to mess with. The cassowary lives in the rainforests of Australia and New Guinea and is the heaviest bird in Australia and the second heaviest in the world. But it's not just its size that makes it dangerous — it has a huge, sharp toenail on the innermost of its three toes that can tear apart large animals or humans.

5. Steamer Duck

They may look like the typical duck, but these stout, South American sea ducks are known to be aggressive, and three out of the four species of steamer ducks are flightless. They flap their wings into the surface of the water and use their feet to swim, causing water to go flying in similar fashion to a steamboat. This approach, along with their aggression and large size, allows them to protect themselves despite not being able to fly.

6. Galapagos Flightless Cormorant

The heaviest of the cormorant species, the Galapagos flightless cormorant is the only one that can't fly. They make up for it with their strong legs and their ability to dive for food in shallow ocean waters. They are endemic to the Galapagos Islands and are often recognized by their small wings that they spread out to dry after a swim.

7. Inaccessible Island Rail

The smallest flightless bird in the world, the Inaccessible Island rail measures only 5 to 6 inches (13 to 15 centimeters) in length and can only be found in one fittingly small place on Earth: Inaccessible Island. The unpopulated island is an extinct volcano in the South Pacific that's, you guessed it, really hard to get to.

Flightless birds definitely prove that a bird is still a bird whether it stays earthbound or explores the skies, and they've become beautiful and unique examples of the nature of evolution. Perhaps the group will even grow larger as time passes, but we'll just have to wait and see.