Silverwings by Kenneth Oppel

Shade is a silverwing bat and has the same curiosity as his deceased father, but it causes him to break a long-standing treaty with the owls. The owls destroy the bats' home, and Shade gets lost in a storm while migrating to their winter home. He finds another bat, Mariam, to help him, and she has a metal band on her leg just like his father. An all-out war between the bats and all other flying creatures looms, so finding the rest of Shade's tribe becomes even more dangerous. The threat worsens further when two giant bats with three-foot wingspans escape from a zoo and start killing pigeons and owls for food. The jungle bats join Shade and Miriam, but Miriam doesn't like they way look at her. She doesn't know the smaller bats are on their menu!

Shade is a runt bat, so he's constantly trying to prove himself. He's also trying to follow a map that was sung to him, so the plot seems like he's following a prophecy. There is an actual prophecy about the future of the silverwing bats, but the message is unclear. The jungle bats present an obvious conflict, and  they have their own plans for silverwings. A theme looks at Man's role in nature, as some bats think Man is a saviour while others think Man should be feared. The metal bands are seen differently too. Some bats think they identify the chosen ones, but others think they identify bats who are doomed. The fact that bats aren't supposed to fly during the day gives that part of the book a folktale quality.