Why can penguins fly?
Long ago the ancestor’s of penguins were birds that could fly. However, they evolved to become superb divers, and in the process lost the power of flight. A flying bird has to minimise its weight. For example, all flying birds have hollow bones. In contrast, to be a successful diver a penguin wants to keep it’s weight high, so they have solid bones. Penguins are excellent divers, they can dive to depths of 1000m and remain down for up to 20 minutes. While penguins cannot fly in the air, they do seem to fly through the water – if you ever get the chance to see penguins swimming in a large and deep pool you will never again say they can’t fly!
Penguins use their wings (called flippers) to propel themselves through water rather than air. Because water is much more dense than air, penguin wings are shorter and stouter than the wings of flying birds. Penguins are also much heavier than similar sized flying birds and have solid bones rather than weight-saving air-filled bones. While these characteristics enable penguins to efficiently “fly” through water, they have had to sacrifice the ability to fly in air to do so. Sources: http://www.penguin.net.nz/faq/faq.
A. Well, in a sense they really do fly, only through the water, not through the air. Penguins have strong wings and strong pectoral muscles to power them. Their bodies are streamlined as if for flight, so they still cut cleanly through the water. But water is much thicker than air, so their wings are shorter and stiffer than a normal bird’s wings. In fact, penguins are the only birds that are unable to fold their wings. Their wing bones are fused straight, making the wing rigid and powerful, like a flipper. By the same token, penguins aren’t nearly as concerned about being light as birds that fly through the air. To dive deep, to catch fast-swimming prey, and to survive frigid temperatures, their bodies have huge fat supplies, heavy muscles, and densely packed feathers. There’s no way they could fly with such short wings and heavy bodies. Penguins are an interesting example of specialization versus compromise. By giving up on flight they’ve been free to evolve bodies that perform super
