The Audubon’s Christmas Bird Count (CBC) is the longest-running community science bird survey in the world, administered by the National Audubon Society.The primary purpose is to collect data on the population, status, and distribution of birds in the Western Hemisphere during the early winter.
The CBC is held annually from December 14 to January 5, inclusive. Each individual count takes place on one single calendar day within that three-week period, chosen by the local organizer.
The long-term data collected (dating back to 1900) is a crucial resource used by researchers and conservation biologists to study bird population trends and inform conservation strategies.
The census is conducted within pre-established, fixed count circles, each with a diameter of 15 miles. There are thousands of these circles across the U.S., Canada, and other countries in the Western Hemisphere.
The CBC is a major volunteer effort and is open to birders of all skill levels, with participation being free. Volunteers join a field team and follow a specific route within the count circle, counting every bird they see or hear throughout the day. Beginners are typically paired with more experienced birders.
To join, you must arrange participation in advance by locating a count circle near you and contacting the circle compiler.
https://www.audubon.org/community-science/christmas-bird-count/
