The longest running citizen science survey in the world, Audubon’s annual Christmas Bird Count will take place from Dec. 14  to Jan. 5. Tens of thousands of volunteers throughout North America will brave winter weather to add a new layer to over a century of data.

Last year’s count shattered records. More than 2,100 counts and 60,753 people tallied 2,319 species and 55,951,707 total birds.That’s nearly 56 million birds.Citizen scientists spotted 200 more species than during the previous year’s Christmas Bird Count.

Counts took place in all 50 states, all Canadian provinces, plus several Central and South American countries, Guam, Mariana Islands, Bermuda , Bahamas, the Dominican Republic, Puerto Rico, and the Virgin Islands. Colombia now has more Christmas Bird Count circles than any other country outside the United States and Canada. The census is becoming the most important monitoring system for biodiversity in the country.

Scientists rely on the remarkable trend data of Audubon’s Christmas Bird Count to better understand how birds and the environment are faring – and what needs to be done to protect them. Data from Audubon’s signature Citizen Science program are at the heart of numerous peer-reviewed scientific studies. The data informs the U.S. State of the Birds Report, issued by the Department of the Interior each spring. Christmas Bird Count analyses also revealed the dramatic impact climate change is having on birds across the continent.

The Audubon Christmas Bird Count began in 1900 when Frank Chapman, founder of Bird-Lore suggested an alternative to the “side hunt,” in which teams competed to see who could shoot the most game, including birds. Chapman proposed that people “hunt” birds only to count them. Now binocular brigades often brave winter’s chill, ice and snow to record changes in resident populations before spring migrants return.

“The Christmas Bird Count becomes more important every year;” said Audubon President David Yarnold in a press release. “The information gathered by its army of dedicated volunteers leads directly to solutions. At a time when people wonder if individual actions can make a difference, we know that our volunteers enable scientists to learn about the impacts of environmental threats like climate change and habitat loss. That’s good news not just for birds but for all of us.”

Audubon Christmas Bird Count data not only helps identify birds in most urgent need of conservation action; it reveals success stories. The Christmas Bird Count helped document the comeback of the previously endangered Bald Eagle, and significant increases in waterfowl populations, both the result of conservation efforts.

“Everyone who takes part in the Christmas Bird Count plays a critical role in helping us focus attention and conservation where it is most needed.” said Audubon’s Director of Bird conservation, Dr. Greg Butcher. “In addition to Audubon’s reports on the impacts of climate change on birds and our analysis of common Birds in decline, it is the foundation for Audubon’s WatchList, which most identified species in dire need of conservation help.”

Counts are often family or community traditions that make for fascinating stories. Accuracy is assured by having new participants join an established group that includes at least one experienced birdwatcher. Count volunteers follow specified routes through a designated 15-mile circle or can arrange in advance to count the birds at home feeders inside the circle and submit the results to a designated compiler. All individual Christmas Bird Counts are conducted between Dec. 14 and Jan. 5 each season, with each individual count occupying a single calendar day.