You can turn into a raven and take wing, no longer earthbound.

Daily   ✦     Primal
Free Action      Personal

Prerequisite: You must have the wild shape power.

Effect: Until the end of the encounter, you can use wild shape to assume the form of a Tiny raven. In this form, you gain a fly speed equal to your speed, and your walking speed becomes 2. You can't attack, pick up anything, or manipulate objects.
    Until this power ends, you can use wild shape to change among this form, another beast form, and your humanoid form.

Published in Player's Handbook 2, page(s) 88.