Why Can’t Penguins Fly

If you have ever seen a penguin walk or swim, you must have wondered why can’t penguins fly. After all, penguins flippers look like wings, and their bodies are covered in feathers. Even when penguins swim through water, the swimming motion makes it look like they are flying. The reason behind the flightlessness of penguins goes into their physiology, biology, and evolutionary traits.

Penguins are one of the few flightless birds, but they are unique because they have evolved to swim and hunt underwater. Penguins also live in extreme weather conditions of the Antarctic region which makes it difficult for them to spend energy in flying and instead of wings, they have evolved to grow flippers that help them in swimming.

In this article, we will take a look at some of the reasons why penguins can’t fly.

1) Evolution

As penguins evolved, they lost their ability to fly so that they could become efficient divers. With fish and krill being their primary food source, penguins evolved to give up flying and developed strong swimming and underwater diving abilities.

The feathers on their bodies can trap air bubbles that help them in swimming faster. Their skin is thick, and the feathers also provide insulation from the cold water. Their bodies are also streamlined that helps them to enter and exit the water in a more efficient manner.

Penguin Makes Flying Motion with Flippers
Penguin Makes Flying Motion with Flippers

2) Body Structure

Penguins that live solely in the Antarctic region have large deposits of fat on their body that helps them to survive the cold weather. The temperature can fall as low as -40 degrees F. The fat also acts as an energy source when penguins go through long periods of fasting. While diving, the fat deposits help penguins dive deeper to catch a variety of fish. The deepest dive by an Emperor Penguin was recorded at 565 m.

3) Availability of Food

For penguins, a whole colony can go through large amounts of fish in a very short time period. A single Emperor Penguin can consume nearly 11 pounds of fish per day. Thus, penguins must move to new feeding grounds in search of food.

But in the Antarctic region, traveling by land is often difficult which is why penguins evolved to swim fast so that they can reach new feeding grounds. Swimming saves time and it is a faster way to scout for new locations where the penguins can find a wide variety of fish. Swimming underwater also helps penguins escape land-based predators and they are quick swimmers who can easily outswim any predators in the water.

Underwater Penguin Looks Like Its Flying
Underwater Penguin Looks Like Its Flying

4) Wing Structure

Penguin wings are designed to be more efficient underwater than in the air. Their wing bones cannot bend which is why penguins use their wings as flippers for powerful movement when swimming underwater or when they need to exit the water. They also use their wings and feet for moving on the ice while lying on their stomach.

5) Heavy Bones

Penguin bones are thicker as compared to bones of birds that are hollow and lighter which makes flight easy. As penguins had no need to fly to catch food or move from one place to another, their bones evolved to be heavier and denser. The higher density of the bones makes it easier for penguins to dive deeper into the water to hunt for fish.

6) Dense Plumage

Penguins have dense feathers all over their body which trap air and make it easier for penguins to swim under the water’s surface. The trapped air also acts as insulation to save penguins from cold water which can reach temperatures as low as -0.4 degrees F. As the plumage gives the penguins an advantage in cold weather conditions, its function to aid in flight gradually decreased and penguins became adept swimmers.

7) Heavy Weight

For their size, penguins weigh heavier than most birds, and this is also one of the reasons why they can’t fly. They have a thick layer of fat under their skin that is useful for keeping them insulated and acts as a source of energy when there is a scarcity of food. Their plumage also makes them heavy which makes flight an impossibility. Even smaller penguins have heavy bones and thick plumage that makes them better swimmers.

8) Breast Muscles

Birds that have adapted to fly also have very strong chest muscles which allow them to flap their wings and stay afloat in the air. While penguins have strong chest muscles, they are not strong enough to facilitate flight. Their chests also form a large part of their body which gives them a sleek appearance that is ideal for swimming.

9) Lung Capacity

Flying takes a lot of energy and birds have highly developed a cardiovascular system that helps them in flying efficiently. Penguin lungs have evolved to work for holding their breath underwater so that they can dive deeper for long durations and catch krill or fish.


To sum up, the inability of penguins to fly can be narrowed down to evolution that helped these birds become better swimmers and survivors in the cold Antarctic regions. While a penguin swimming out of the water with great force might look like it’s flying for a few seconds, the bodies of these birds have adapted better for swimming. Their wings evolved to look like flippers, and the underwater swimming motion of the penguin makes it look like it’s flying but through the water.

From an evolutionary point of view, it made more sense for penguins to lose the ability to fly and instead develop more powerful swimming abilities. Their survival and the survival of their young ones were dependent on their capacity to swim, hunt, and survive the harsh weather conditions in Antarctica.

Do you have any theories about why penguins can’t fly? Please feel free to share your thoughts in the comment section.






Image Credit:

  1. Penguin Makes Flying Motion with Flippers by Michelle_Raponi / Pixabay License
  2. Underwater Penguin Looks Like Its Flying by PublicCo / Pixabay License

I got interested in penguins from a young age and as I grew I realized that penguins are such fascinating birds. I made it a mission to create a website where all information about penguins could be accessed in an easy to read format.

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