Birds are a recurring species of creature in the Metroid series.
A type of bird appears in Metroid Prime above certain rooms in the Chozo Ruins and the Tallon Overworld. It appears to be a type of large crow. They cannot be scanned, but they can be shot at. Once hit, they explode in a puff of feathers. They often appear in very large flocks. In the game's data, they are referred to as "Tweety".
These birds have an unused death animation where instead of exploding into feathers, they fall spiraling from the sky in a similar manner to the ducks in Duck Hunt.
A similar species can be seen high in the skies of the Temple Grounds. Unlike the birds seen on Tallon IV, these are indestructible, and are extremely slender in shape. Animation titles refer to them as "Sandlands Birds".