Midway Atoll is a haven for more than 3 million seabirds, including the largest Laysan albatross colony in the world — heard in this recording through the high-pitched whistles and clacking bills of its breeding display. They are joined by White Terns. A circular atoll made of three coral islets, Midway is one link in a chain of tiny islands and seamounts that form the Papahānaumokuākea Marine National Monument. This protected marine area spans 1.5 million square kilometers (582,578 square miles) in the Pacific Ocean and contains some of the healthiest coral reefs on Earth.