NEW YORK —For the 117th year, the National Audubon Society is organizing its annual Christmas Bird Count. Between December 14th and January 5th, tens of thousands of bird-loving volunteers will participate in counts across the Western Hemisphere. The data collected by participants continues to contribute to one of only two large existing pools of information notifying ornithologists and conservation biologists about what conservation action is required to protect birds and the places they need.

The Christmas Bird Count is the longest-running wildlife census in the world. Each individual count takes place in a 15-mile-wide circle and is led by a compiler responsible for organizing volunteers and submitting observations to Audubon. Within each circle, participants tally all birds seen or heard that day—not just the species but total numbers to provide a clear idea of the health of that particular population.

"It's never been easier to be a citizen scientist and it's never been more important to be one," said David Yarnold (@david_yarnold), president and CEO of the National Audubon Society. "Birds and the people who watch them are noticing changes. Using the data gathered by more than a century of Christmas Bird Counts, Audubon will keep protecting birds and the places they need. I'm incredibly proud of the volunteers that contribute to this tradition."

Christmas Bird Count data have been used in more than 200 peer-reviewed articles, including Audubon's landmark Birds and Climate Change Report, which found that more than half of the bird species in North America are threatened by a changing climate. When combined with other surveys such as the Breeding Bird Survey, it provides a picture of how the continent's bird populations have changed in time and space over the past hundred years. The long term perspective is vital for conservationists. It informs strategies to protect birds and their habitat, and helps identify environmental issues with implications for people as well.

Last year, the 116th Christmas Bird Count included a record-setting 2,505 count circles, with 1,902 counts in the United States, 471 in Canada and 132 in Latin America, the Caribbean, Bermuda and the Pacific Islands. In total, 76,669 observers out in the field tallied up 58,878,071 birds representing 2,607 different species—about one-quarter of the world's known avifauna. Approximately 5 percent of the North American landmass was surveyed by the Christmas Bird Count.

"From Alaska's Arctic coast to Tierra del Fuego, and from Newfoundland to Los Angeles, the 117th CBC is a tradition that everyone can participate in," said Geoff LeBaron, Audubon's Christmas Bird Count director. "Adding observations to more than a century of data helps scientists and conservationists observe trends that will help make our work more impactful."

A disturbing finding from last year was the continued decline of the Northern Bobwhite, the only native quail in the eastern United States. Record low numbers of this species were observed from the Midwestern states to the Mid-Atlantic and down to Florida. Meanwhile the Eurasian Collared-Dove, introduced to the Bahamas in the 1970s from its native Europe, was observed in record high numbers from North Carolina throughout the Midwest and northward to the Great Lakes and southern Canada. These two species are of great concern as Audubon embarks on its 117th count.

Beginning on Christmas Day in 1900, Dr. Frank M. Chapman, founder of Bird-Lore – which evolved into Audubon magazine -- proposed a new holiday tradition that would count birds during the holidays rather than hunt them. Conservation was in its beginning stages in that era, and many observers and scientists were becoming concerned about declining bird populations. So began the Christmas Bird Count. 117 years later, the tradition continues and still manages to bring out the best in people.

The Audubon Christmas Bird Count is a citizen science project organized by the National Audubon Society. There is no fee to participate and the quarterly report, American Birds, is available online. Counts are open to birders of all skill levels and Audubon's free Bird Guide app makes it even easier to learn more. For more information and to find a count near you visi www.christmasbirdcount.org.

The National Audubon Society saves birds and their habitats throughout the Americas using science, advocacy, education and on-the-ground conservation. Audubon's state programs, nature centers, chapters and partners have an unparalleled wingspan that reaches millions of people each year to inform, inspire and unite diverse communities in conservation action. Since 1905, Audubon's vision has been a world in which people and wildlife thrive. Audubon is a nonprofit conservation organization. Learn more a www.audubon.org and follow @audubonsociety.