The Bird Key, also known as the Eagle Key, is a quest item from The Legend of Zelda: Link's Awakening. This key is needed to open to way to Eagle's Tower, the seventh dungeon on Koholint Island. It is located inside a cave in the Tal Tal Mountain Range.
In order to obtain the Bird Key, Link has to revive the Flying Rooster buried beneath the weather vane in Mabe Village by playing the "Frog's Song of Soul" on his Ocarina. With the Flying Rooster now revived, Link can pick the rooster up with the Power Bracelet to make it carry him by flight. Link must use the aid of the Flying Rooster to cross a great chasm within the cave in the Tal Tal Mountain Range. The Bird Key can then be used in the keyhole stone near Eagle's Tower. The tower rotates 180°, revealing the staircase leading inside.