Each fall and spring, millions of birds travel the Pacific Flyway, the westernmost of the four major North American bird migration routes. The landscapes they cross vary from wetlands to farmland to concrete, inhabited not only by wildlife but also by farmers, suburban families, and major cities. In the twentieth century, farmers used the wetlands to irrigate their crops, transforming the landscape and putting migratory birds at risk. The U.S. Fish and Wildlife Service responded by establishing...
