The passing of the Migratory Bird Treaty Act of 1918 in the United States resulted in a need for more information on bird migration. Frederick Charles Lincoln was put in charge and improved methods for trapping and banding, developed record-keeping procedures, recruited banders, fostered international cooperation, and promoted banding as a tool for research and wildlife management. He found it was possible to establish the routes used by waterfowl during their annual migrations and he developed the flyway concept, a key idea in the management and regulation of hunting of migratory birds; by establishing the routes used, estimates of population sizes could be made and suitable protection could be put in place.
The special vulnerability of waterfowl and shorebirds on their international migrations, with their specific needs for suitable wetland stopovers, resulted in the signing of the Ramsar Convention in 1971. As a result, over 2300 Ramsar sites have been established around the world, many being situated on flyways where they provide the vital habitat needed by the birds on their journeys.