The North American Bird Phenology Program houses a unique and largely forgotten collection of six million Migration Observer Cards that illuminate migration patterns and population status of the birds of North America. These handwritten cards contain almost all of what was known of bird distribution and natural history from the latter part of the 19th century through World War II. The bulk of the records are the result of the work of a network of observers who recorded migration arrival dates in the spring and fall in a program that, in its heyday, involved 3000 participants. Today, those records are being processed and placed into a modern database for analysis. This information will be used, along with recently collected arrival times of migrant birds, and in conjunction with historical weather data, to examine how bird migration is being affected by climate change. The information from this analysis will provide critical information on bird distribution, migration timing and migration pathways and how they are changing. There is no other program that has this depth of information that can help us understand the effect that global climate change has on bird populations across the continent. History The program began in 1881 by Wells W. Cooke, who wanted to broaden knowledge and understanding of bird migration. While teaching on the White Earth Indian Reservation in Minnesota, Cooke began noting the arrival dates of migratory birds. He later coordinated volunteers throughout the Mississippi Flyway to collect arrival and departure data. His success sparked the interest of the newly formed American Ornithologists' Union (AOU), who convened a committee on the distribution and migration of birds and chose C. Hart Merriam to be its chief. The AOU expanded the volunteer network to include the entire United States, Canada, and a portion of the West Indies. The program outgrew the capabilities of the AOU and was then passed, in the late 1880s, to the Division of Economic Ornithology where it reached its greatest extent of 3000 volunteers. The Division of Economic Ornithology would later become the Bureau of Biological Survey and eventually lead to the creation of the US Fish and Wildlife Service. Although the program was actively maintained by the Federal Government, participation gradually declined and, in 1970, the program was closed. For many years since, these records have been kept safe by the United States Geological Survey (USGS). Wells W. Cooke Wells W. Cooke, son