Arctic tundra swans mark an early sign of spring. Winging their way northward, tundra swans hoot and holler from high above, announcing the change of season like a rowdy crowd at a sporting event. Canada’s grasslands, lakes, marshes and forests are coming alive as millions of migrating birds herald the arrival of spring in one of the greatest shows on Earth. Celebrate this natural spectacle with Ducks Unlimited Canada during Spring Migration Week April 10 - 16.