20 Animal Journeys That Still Defy Explanation

The first trip begins in a hurry. A hatchling breaks from the sand, crosses a dangerous beach, and heads toward the water before it has had time to understand the world. Years later, many female sea turtles return to nest near the same coastline where they began. Scientists have found strong evidence that magnetic cues help guide them, almost like an invisible address tied to the beach. The Earth’s field changes from place to place, and turtles appear able to use those differences while navigating. It is a gentle but astonishing idea: a beach can leave a kind of magnetic memory.