Curious Kids: How many bones do penguins have? | Kiowa County Press

Specialized anatomy means that flightless penguins are master swimmers. Christopher Michel , CC BY-SA

Julie Sheldon, University of Tennessee

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How many bones do penguins have? – Sawyer, 7, Media, Pennsylvania


Like a zoo and wildlife veterinarian, I sometimes take care of penguins – both in the wild and in aquariums and zoos.

I’m always fascinated when I have to take x-rays of an injured bird that might have a broken bone, is sick or has difficulty moving. While penguins may look like simple torpedo-shaped ice waddles, their bodies are actually quite complex.

Even though they look nothing like the people or animals you might encounter every day – like dogs and cats – they have similar skeletons and joints. They even have knees and elbows, but have about half as many bones. A human skeleton is made up of 206 bones. A penguin has only 112 in its entire body.

Penguins have far fewer bones than many animals.
X-ray of a penguin. University of Tennessee College of Veterinary Medicine, Author provided

All birds have evolved for flight, with feathers, wings and bodies that allow them to soar high in the sky. To achieve liftoff, over time penguins have evolved to have fewer bones in their skeleton.

How did they do this? Some of their bones actually fused, including their ankles. Unlike humans, who have two main ankle bones, a bird leg bone connects directly with his feet and toes.

Birds also have fewer bones in their spines than many animals. Their lower back bones came together into a single bone, called the synacrum. The only other animals to have this type of spine were the dinosaurs. For birds, it helps them keep their bodies in a horizontal position without straining their back muscles when flying or swimming.

Humbolt penguins live in South America, Chile and Peru.
Wild Humboldt penguins. Julie D. Sheldon, Author provided

Bird bones in general are unique. They are light and hollow, which allows the animal to take flight. Because birds need a lot of oxygen for strenuous activity like flying, their bones are filled with spaces for air, and they also have nine air sacs that surround their lungs.

But wait, you might be thinking, “Penguins don’t fly at all. It’s true, they evolved for life on land and in water, and they have a unique skeleton compared to many other birds.

The first penguins, which appeared shortly after the extinction of the dinosaurs, 66 million years ago, were unable to fly. Ten million years later, they had become great swimmers. Current species spend up to 75% of their time in the ocean. This meant they had to get heavier so they could dive underwater to hunt for food.

Penguins have grown dense and heavy bones that don’t have the air pockets that flying birds have. This helped offset the air sacs around their lungs. Their bulky bones prevent them from floating to the surface of the water, like a diver who attaches himself to a weight belt to submerge himself.

Penguins are particularly adapted for swimming underwater.

The wings of penguins are also different because these birds need to swim, not soar through the sky. The penguins’ wings have morphed into what looks like short, flat, rigid fins that don’t bend like flying birds do. They also have fewer bones than other birds.

Their wings act like paddles, helping them run through water at high speed. Gentoo penguins can swim up to 22 mph. That’s a lot faster than Olympic champion swimmer Michael Phelps, who broke a world record for humans at 5.5 mph.

The combination of heavy bones and powerful fin-like wings allow penguins to descend quickly and dive incredibly deep to hunt fish, krill and other food. An emperor penguin can descend to at least 1,500 feet, approximately the length of five football fields.

Thanks to their reduced number of dense bones and other cool adaptations, penguins are the champions of open water.


Hello, curious little ones! Do you have a question you would like an expert to answer? Have an adult send your question to [email protected] Please let us know your name, age and the city where you live.

And since curiosity has no age – adults, let us know your questions too. We cannot answer all questions, but we will do our best.

The conversation

Julie Sheldon, Assistant Clinical Professor of Small Animal Clinical Sciences, University of Tennessee

This article is republished from The conversation under Creative Commons license. Read it original article.

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