How does Billy manage to survive after he buries the wolf?

Billy buries the wolf, notes that the kits die in her womb, and leads his horse away. He makes a bow and arrow from a holly limb and cane. He and Bird live on the sparse gleanings of the land, which include a few trout for Billy and grass or lichen for Bird. They arrive at El Tigre where a girl asks if he's sick then invites him in for a meal of tortillas and beans.