system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If birds migrate south for the winter, why do they bother coming back? Why not stay south permanently and live without travelling twice a year?
gpt
To use the example of snow geese, they're able to quickly come back North to a place with little competition for food and few predators so they can safely nest and mate.

Other birds have similar reasons. They can find sources of food or safe places to have chicks without competition or predators.