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Why are penguins unable to fly?

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Southern rockhopper penguin (Eudyptes chrysocome chrysocome) standing on grass with a colony of penguins on rocky cliffs by the sea in the Falkland Islands. — penguin Most penguins are black and white, but the rockhopper penguin—like the southern rockhopper (*Eudyptes chrysocome*) in the foreground of this image—adds more colors. Rockhoppers have distinctive red eyes and a thin stripe of yellow feathers above each eye. They also have a crest of upright black feathers on top of their heads.

Penguins are unable to fly because their wings have evolved into flippers, which are highly adapted for swimming and diving underwater. This evolutionary path has resulted in their flightlessness, as their bodies are now optimized for aquatic locomotion rather than aerial flight. While they possess wings, these are used as paddles for propulsion through water, not for soaring through the air. This adaptation is a secondary development, meaning their ancestors could fly, but penguins specialized for a marine environment.123