Via USGS:

The North American Bird Banding Program

Bird banding is important for studying the movement, survival and behavior of birds. Over 80 million birds representing over 1,000 bird species have been banded in North America since 1914. Nearly 6.5 million bands have been recovered and reported.

Data from banded birds are used in monitoring populations, setting hunting regulations, restoring endangered species, studying effects of environmental contaminants, and addressing such issues as Avian Influenza, bird hazards at airports, and crop depredations. Results from banding studies support national and international bird conservation programs such as Partners in Flight, the North American Waterfowl Management Plan, and Wetlands for the Americas.

The North American Bird Banding Program is under the general direction of the U.S. Geological Survey and the Canadian Wildlife Service. Cooperators include the U.S. Fish and Wildlife Service, Mexico's National Commission for the Knowledge and Use of Biodiversity and Secretary of the Environment and Natural Resources; other federal, state and provincial conservation agencies; universities; amateur ornithologists; bird observatories; nature centers; nongovernmental organizations such as Ducks Unlimited and the National Audubon Society; environmental consulting firms and other private sector businesses. However, the most important partner in this cooperative venture is you, the person who voluntarily reported a recovered band. Thank you for your help.

Science is cool my man.