Discover the world's best birding trails—each linking all of a region's birding sites—and the spectacular species that reside there. Saguaro National Park's Cactus Forest Trail, home to gilded flickers and myriad other desert birds. Alaska's Lower Kenai River Trail, a favorite gathering place for bald eagles. And a hummingbird paradise: the trails of Costa Rica's Monteverde Cloud Forest. Each month's spread includes a map and detailed text.