For over a hundred years, the Audubon Society has conducted an annual Christmas Bird Count (CBC) to create a snapshot of bird numbers and distribution throughout America. The "Christmas" in Christmas Bird Count is something of a misnomer; the count takes place between December 14 and January 5, based on the scheduling of each area's locations.
This annual tradition provides invaluable scientific data.
This is not to be confused with the Great Backyard Bird Count, a joint project of the Cornell Lab of Ornithology and the Audubon Society, which happens in February every year. The Great Backyard Bird Count is specifically aimed at getting bird counts from individual small areas (i.e. back yards), and it is a much more informal event.
The Christmas Bird Count is a large, nation-wide coordinated effort that takes place thanks to groups of volunteer birdwatchers. In past years there has been a $5 fee to participate, but the Audubon Society is waiving that fee for this year.
Data from the Christmas Bird Count has been invaluable in the past. It has identified declining populations which conservation societies were then able to work to protect, like the American Black Duck. It has demonstrated the effects of climate change on bird migrations, which was used in the recent Audubon & Climate Change presentation. The data from the Christmas Bird Count is used by the EPA and the U.S. Fish & Wildlife Service to help determine policy, as well as by countless independent researchers every year.
The Texas Christmas Bird Count results are already in, for example, and the changes over the past few years are astounding. Between the record drought in Texas and the effects of climate change on migratory patterns, this was a tumultuous year for bird populations in Texas. And no one would have been the wiser, if it hadn't been for the Christmas Bird Count!
To join a Christmas Bird Count, the first step is to find the one in your area. Each Count takes place inside a specific geographic sampling area. If you are lucky enough to live within the sampling area, you can arrange with the group leader (known as the Count Compiler) to track the birds that visit your back yard during the specified time window. Bird watchers of all experience levels are welcome, but as many counts involve difficult terrain, winter weather, and long hours spent outside waiting for something to happen, it may not be the best event for younger children.