Twice each year millions of North American landbirds migrate thousands of kilometers between their breeding and wintering grounds. In spring and fall migrants must cope with natural and anthropogenic challenges to a successful migration. As recognition grows concerning the need for full life cycle conservation, so does the call for research and monitoring geared toward understanding the behavior of migratory birds en route and for conservation and management plans aimed at protecting habitats, including migration aerohabitats, that support their successful migration.