Migration refers to the movement of living organisms from one place to another.
Food consumption plays a vital role in migration. When animals are in particular habitat, they are already adapted there, there's a food chain and they already know how and where to get their food.
Relocating to a new place can affect this, and they have to adapt again and look for what to eat etc. Therefore, the essential question that Enzo should ask about the migration of the Canadian goose is that "what do they eat?".