birds know where to migrate thanks to a number of different mechanisms.

1) birds have a biological "compass" in their brains or eyes. it helps them sense the Earth's magnetic field, which allows them to determine where they are heading.

2) birds can use the sun's position during the day and different star patterns at night.

3) birds often follow visual landmarks, such as mountain ranges, coastlines, and rivers.

4) birds are often born with a built-in, genetic map. it can guide them during their first migration.

#birdfacts