Migration Flyways: Atlantic Route Mississipi Route Central Route Pacific Route The seasonal appearance or disappearance of birds has been the focus of speculation and wonder for thousands of years. Aristotle thought that birds hibernate in winter. Others theorized that birds overwinter on the moon, or that small birds, quite incapable of long journeys, must hitch rides on the backs of larger birds, such as geese or cranes. While we know far more about migrating species today, there are still great mysteries: How does a fledgling American Golden-Plover make a journey of 10,000 miles along a route he's never flown before? How does the small Savannah Sparrow manage to fly from Mexico to Alaska -- 6,000 miles distant -- and still nest within a few yards of its previous home? How and why do tundra swans mate for life? The migration paths these birds follow are another mystery. While there are many routes taken by migratory birds -- even different routes followed by the same species -- there are some routes in North America that are particularly important. Click on one of the four examples below. Atlantic Route Mississipi Route Central Route Pacific Route