Only Birds Know Why They Migrate
Humans aren’t the only species who head to warmer climates to escape the chill of winter when their nesting conditions become unsuitable. If you’ve ever booked a flight to a tropical country once that first snowflake fell from the sky, you’re not alone. Birds also migrate incredibly long distances once winter sets in. But scientists have no idea how birds migrate or how they manage the migration. They’ll fly hundreds of thousands of miles to find the perfect conditions and habitats to breed and live. Some birds fly up to 4,350 miles (7,000 kilometers). That’s the distance from Andorra to the USA. Birds use sight, smell, and even the stars to migrate. They follow Earth’s magnetic field with their biological compass. Scientists theorize that birds sense an invisible magnetic field with built-in hardware, though they’re not entirely sure (Vox).