The Great Migrations Explained

Migration is one of nature's greatest spectacles. Over a million wildebeest circle the Serengeti chasing the rains, Arctic terns fly pole to pole, and monarch butterflies travel thousands of miles across generations to reach the same forests their ancestors left.

How they find their way remains astonishing. Migrating animals use a mix of the sun and stars, landmarks, smell, and even a built-in sense of Earth's magnetic field. These journeys connect distant habitats — which is why protecting migration routes is as important as protecting the destinations themselves.