Migratory birds fly south during autumn and return north in spring.
They fly.
Cause in the North it can get really cold and birds don't mostly survive in the cold so they fly south were it's warmer or hotter.
humming birds migrate the same way the other birds do. Like when it is cold in north they fly south and when it is cold in the south they fly north.
migratory behavior, where animals travel long distances to find better habitats or resources as the seasons change. It helps them avoid harsh weather conditions and find food more easily.
Birds Fly South was created in 2001.
When the Birds Fly South was created in 1945.
When the Birds Fly South has 223 pages.
Swallows.
They would freeze to death
Many birds migrate to warmer climates in the winter to find food and escape the cold weather. They may travel thousands of miles to reach their wintering grounds, where they can find resources to survive until it is time to return to their breeding grounds in the spring.
Birds do not fly all the way to the southern hemisphere, they fly to the equator.