The nation's longest-running citizen science bird project fuels Audubon science throughout the year.
Christmas Bird Count 2015, Central Park, NYC. Photo: Camilla Cerea/Audubon
Everything you need to know to run your Christmas Bird Count circle
You can add to a century of citizen science data by signing up for a count near you
Hundreds of studies by scientists around the world have put CBC data to use
How the count started, and how the data is used today
Peruse the printed records of past Christmas Bird Count or find a full bibliography for American Birds and Bird Lore.
See the award-winning photos plus our top 100 favorites.