The longest-running bird census provides important data for scientists and conservationists worldwide.
For the 122nd year, the National Audubon Society is organizing the annual Audubon CBC. Between December 14 and January 5, tens of thousands of bird-loving volunteers will participate in counts across the Western Hemisphere all while abiding by Audubon’s COVID-19 guidelines. The twelve decades’ worth of data collected by participants continue 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. Find your local count here.
The Audubon CBC is one of the longest-running wildlife censuses in the world. Each individual count takes place in a 15-mile-wide circle and is led by a compiler responsible for safely organizing volunteers and submitting observations directly 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. Abiding by state and local COVID-19 guidelines is mandatory.
“The Audubon Christmas Bird Count is a great tradition and opportunity for everyone to be a part of more than 12 decades of ongoing community science,” said Geoff LeBaron, Audubon CBC director, who first started leading the community science effort in 1987. “Adding your observations helps scientists and conservationists discover trends that make our work more impactful. Participating in the Audubon CBC is a fun and meaningful way to spend a winter for anyone and everyone.”
When combined with other surveys such as the Breeding Bird Survey, the Audubon CBC 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. For example, in 2019, Science published a study using decades of Audubon CBC data to describe a grim picture: a steady decline of nearly three billion North American birds since 1970, primarily as a result of human activities. Over the years, Audubon CBC data have been used in more than 300 peer-reviewed articles.
Audubon CBC data are also used to measure how birds are already responding to climate change. By tracking how bird ranges have moved over time, conservation efforts can be prioritized in areas that are important for birds today and in a climate-altered future. With two-thirds of North American bird species at increasing risk of extinction by the end of this century, Audubon CBC data is more important than ever for effective conservation.
Last year, the 121st Audubon CBC included 2,459 count circles worldwide. In total, 72,815 observers out in the field and watching feeders tallied up more than 44 million birds representing 2,355 different species—around one-quarter of the world’s known avifauna. To observe the trends of any particular species over the last twelve decades, please take a look here.
Some species-level highlights (taken from Geoff LeBaron’s Summary of the 121st Audubon CBC):
- There was a huge southward irruption of Purple Finches, especially across eastern North America. This species inundated feeding stations as far south as northern Florida and the Gulf Coast.
- Pileated Woodpecker numbers were up across much of the continent. North America’s largest woodpecker, Pileated Woodpeckers appear to be adapting well to suburban environments.
- Neotropical migrant warblers are lingering in North America during the Audubon CBC period. Last season’s results included quite an array of wood-warblers that are not normally expected in the United States or Canada, including American Redstart, Blue-winged, Chestnut-sided, Grace’s, Lucy’s, MacGillivray’s, Prothonotary, Tennessee, Worm-eating, and Yellow Warblers. This may be due to moderating winter temperatures that allow neotropical migrants to stick around longer instead of completing their southward journeys to wintering grounds.
The Audubon CBC is a community science project organized by the National Audubon Society. There is no fee to participate. The Audubon CBC is 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 visit ChristmasBirdCount.org. To view Audubon CBC-branded apparel, accessories and other items for purchase, please visit the Audubon Store.
To sign up for an Audubon CBC and ensure your bird count data make it into the official Audubon database, please find the circle nearest you and register with your local Audubon CBC compiler on this map here. All Audubon CBC data must be submitted through the official compiler to be added to the long-running census.
The National Audubon Society protects birds and the places they need, today and tomorrow, 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 at Audubon.org and @audubonsociety.
By Nicolas Gonzales, Audobon.org