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How a Christmas Bird Count Works

Bird watching New England

Volunteers move quickly to identify and count birds in a small geographic circle on a CBC

The Christmas Bird Count is now in its 124th year. This annual event is an important part of understanding bird population changes, increasingly affected by human activities. National Audubon, stewards of this tradition, has a wealth of information on their website about the Christmas Bird Count.

If you are a first-time volunteer and would like to participate, contact a coordinator in any town accepting new volunteers (see the Map link below). If you live within the boundary we encourage you to contact your town’s coordinator, but you are welcome to join any town sector accepting new volunteers. Or you can join Spark Birding in Concord for the 2023 count.

How It Works

Each local Christmas Bird Count is set up in a similar way with a 15-mile diameter zone called a Circle. Each Circle has a Compiler, an expert who reports all the data and knows the rules. Rules are needed to make sure counts and birds are recorded correctly. If you interested in knowing all the rules, check out the Audubon Christmas Bird Count Compiler’s Manual.

Volunteers who participate in a count are called “Observers”. Your compiler will assign you to a particular area within the circle. Audubon has an interactive Map of Active Circles that lists all the Circle’s in your area, with the contact person. Depending on where your Circle is located and what you’ve been assigned, your day will be spent walking, on a driving tour, or likely a combination of both. The members of your circle report on all the birds and species they see. If your home is located in a CBC circle, you report the birds that visit your feeder from home on the day of the count as long as you arrange this with the compiler.

Recording Your Sightings

If you participate in a Christmas Bird Count, there are various ways to gather and record data. Most official counts have downloadable forms listing likely birds found in winter within the 15-mile circle.

Much birding is done in a small group, by driving and stopping, typically with a dozen or more stops. On colder days after a longer stop, a respite in a heated vehicle is advisable. Have your checklist on a solid clipboard with a holder for your pen or pencil. Each time you return, go through the list and discuss with your small group how many blue jays and write down the consensus # followed by a comma.

Other Tips on Sightings

Some volunteers may want to use a recording device to remember, or simply estimate numbers at end of each location visit. Have a camera ready to take photos of unusual birds or ones unknown to you. Take some notes of this mystery bird's plumage details, size, habitat, and actions - you may be quizzed on your claim or informed of what you did see by some expert. Notes and visual evidence are important. It’s rewarding to be congratulated on seeing a rarity.

What Happens to Your Data

At the end of the day you complete your checklist on sightings, fill in data on miles and hours you birded individually or as a party, then email or phone compilers. The data from you, your circle, your region, the country, and the world is collected and organized by the National Audubon Society to give a world-wide snapshot of bird population movement and how species are faring.

To get a deeper understand of The Christmas Bird Count and Winter Birds, signup for the Spark Birding course Winter Birds of Inland New England.


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