Silverwing (The Silverwing Trilogy)

Shade is a young silverwing bat, the runt of his colony. But he's determined to prove himself on the long, dangerous winter migration to Hibernaculum, millions of wingbeats to the south. During a fierce storm, he loses the others and soon faces the most incredible journey of his young life. Desperately searching for a way to rejoin his flock, Shade meets a remarkable cast of characters: Marina, a Brightwing bat with a strange metal band on her leg; Zephyr, a mystical albino bat with an unusual gift; and Goth, a gigantic carnivorous vampire bat. But which ones are friends and which ones are enemies? In this epic story of adventure and suspense, Shade is going to need all the help he can find -- if he hopes to ever see his family again.