Mid-winter Waterfowl Inventory

These surveys are conducted cooperatively by state wildlife agencies and the Migratory Bird Program to provide an index of waterfowl population abundance during winter. For some goose and duck species, adequate monitoring during the spring and summer is not possible because they nest in areas not well covered by the breeding population surveys. A nationwide effort to survey waterfowl is conducted annually in January, to provide information on population trends, distribution on the wintering grounds, and habitat use for certain waterfowl species. Survey design differs among states, with some states conducting a cruise survey, where crews attempt to count all waterfowl, and others using a transect-based design, where a sample of counts is extrapolated over the survey area.

For more information on the population status of waterfowl, please visit the following library collections:

• Waterfowl Population Status Reports
• Migratory Bird Flyway Data Books