What's the secret to bird migration?
Great question! Many studies have tried to come up with the answer, or answers, to this question and the complete story is still unknown.
Migratory birds have a remarkable ability to migrate to often-distant winter homes and then to find their way back to breeding areas each year. Their travels may take them halfway around the world, along convoluted paths, through storms, and over mountains and oceans. Yet most migrants manage to make the trip, following the same path each year with remarkable consistency. Some bird banding stations have captured the same bird in the same location one or more years apart, even after the bird has traveled hundreds or even thousands of miles.

Arctic Tern
Some Arctic Terns make a round trip each year from above the Arctic Circle to the Antarctic and back again. In some cases they travel 25,000 miles in a single year.
To migrate successfully, birds need an internal map to give them an idea of their current position and a compass to keep them moving in the direction of their destination. Try this mind game to see how you would fare.
Mind game...
Imagine that it is fall. You are blindfolded and placed in an airplane. The plane lands and you are dropped off somewhere near the border of Canada and the United States. Your blindfold is removed and you are left in the middle of nowhere, on your own to find food and shelter. No one has told you that it is going to become colder and no one has told you that heading south (whatever that means) will take you to a warmer location with more food. What would you do to survive?
If you are lucky, you are a tiny bird, perhaps weighing less than a quarter. Your parents taught you a few songs and which bugs to eat, but the most remarkable knowledge they gave you happened before you hatched from your tiny egg. You were born with the instinct to react to shorter days. You know the best chance for survival is to travel in a specific direction and you have some idea as to how far to travel. This is a remarkable and powerful gift of instinctive knowledge from your parents.