The National Audubon Society has conducted Christmas bird counts since 1900. Volunteers from across North America and beyond take to the field during one calendar day between December 14 and January 5 to record every bird species and individual bird encountered within a designated 15-mile diameter circle. These records now comprise an extensive ornithological database that helps to monitor winter bird populations and the overall health of the environment.

Participants are typically assigned to teams based on their bird identification skill level and endurance. Many counts hold a compilation dinner at the end of the day where results are tabulated and stories shared. A $5.00 participation fee defrays a portion of the cost of tabulating and publishing the count results. Help is needed on most of these counts, so find one that interests you and contact the compiler for more information.