Jawa Scavenger

ASK FANTASY FLIGHT 

Q: If you do not declare defenders, and therefore do not place cards in the edge battle, are you considered to have lost the edge battle?

A: Yes, an undefended edge battle is considered to have automatically been won by the attacking player. Since the other player won an edge battle, you are considered to have lost it, and the Jawa Scavengers are returned to your hand.