Flight Paths is the never-before-told story of how a group of migration-obsessed scientists in the twentieth and twenty-first centuries engaged nearly every branch of science to understand bird migration—from where and when they take off to their flight paths and behaviors, their destinations and the challenges they encounter getting there. Uniting curious minds from across generations, continents, and disciplines, bird enthusiast and science writer Rebecca Heisman traces the development of each technique used for tracking migratory birds, from the first attempts to mark individual birds to the cutting-edge technology that lets ornithologists trace where a bird has been, based on unique DNA markers.