A long-standing program sponsored by the National Audubon Society, the Christmas Bird Count (or CBC), is an early-winter bird census conducted by thousands of volunteer "birders" across the Western Hemisphere. These volunteers go out over a 24-hour period to count birds and remit this data to the Audubon Society.
The Beginning of the Christmas Bird Count
In the 1800's, an annual Christmas event called the "side hunt" took place. In the "side hunt," people chose sides, or teams, and then they all went out to shoot as many birds as they could. The side that shot the largest number of birds won!
A famous ornithologist, Frank Chapman, feared that the then-declining bird population would not be able to withstand this sort of over-hunting, Chapman proposed that instead of shooting birds on Christmas day, people should band together to count birds. This led to the first-ever CBC on Christmas Day 1900, where Frank Chapman and twenty-seven additional birders led some twenty-five Christmas Bird Counts. Together, these Counters identified approximately 18,500 birds and ninety different species!
Why Count Birds?
Aside from preventing the wholesale slaughter of birds of all species on Christmas Day, the data collected by the birders over the last 100 years has helped researchers and conservation biologists to study the long-term health and status of various populations of birds in North America.
Comparing the counts on a year-by-year basis alerts scientists to problematic environmental issues which may be reflected first in the bird population but later in the human population. The CBC also allows scientists and wildlife workers to identify species that are becoming endangered while it is still possible to put measures into place to revive those species.
The CBC has enabled scientists to determine that many common bird sprecies populations have decreased greatly in the last forty years. However, during this same time, species of doves and pigeons have actually expanded their ranges with the development of more and more urban centers.
How the Christmas Bird Count Works
Birders who volunteer to particpate in the CBC are given a designated 15-mile circle in which they will count birds. Within these circles, the volunteers will follow specified routes and count every bird they see or hear during one particular calendar day. Both the bird species and bird number within each species is counted.
Is the CBC Held Only on Christmas Day?
No, there are actual many individual CBC's, all held sometime in the period between December 14th and January 5th, inclusive. During their assigned counting day, tens of thousands of bird enthusiasts rise before dawn, pack up their binoculars and bird guides, and set out as "citizen scientists" to contribute to the Count.
How to Get Involved in the CBC
Every year in early December, prospective Counters can check out the Christmas Bird Count page on the Audubon site to see when the counts will be held for the year and how to get involved.
The CBC takes place within what are called "Count Circles." Each circle is run by a "Count Compiler" who is an experienced birdwatcher and has contributed to the CBC previously. In some cases, you can even elect to stay home and report on the birds that visit your own backyard bird feeder!
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