Fast Facts
993: Number of species currently listed on the ABA checklist770: Number of species counted by ABA big-year record holder John Weigel of Australia605: Number of species Calhoon counted in ABA area during his ABA big year39: Number of states Calhoon visited during his ABA big year272: Number of species Calhoon counted in Tennessee alone10,426: Number of bird species estimated to exist in the world6,100: Number of birds counted by world big-year record holder Arjan Dwarshuis of the Netherlands1,058: Number of birds counted by Calhoon during his world big year3: Number of countries (United States, India and Australia) Calhoon visited for his world big year
In 2015, Kevin Calhoon traversed three countries, 39 states and the remote Aleutian Islands off Alaska’s coast in order to count birds. “I spent a whole lot of time and money,” says Calhoon, assistant curator of forests at the Tennessee Aquarium. It was his “big year.”
Among birders, a “big year” is a competition to see who can ID the most bird species within a particular calendar year and geographic region. Because it is a no-stakes contest, birders may set the scope of their own search, ranging from a single state to the whole world.
A common “play” area is known as the “American Birding Association area,” defined as the 49 continental states, Canada and the French islands of St. Pierre and Miquelon located off the southern coast of Newfoundland. The ABA area also includes adjacent waters up to 200 miles or to the halfway point to the nearest country, whichever is less.
Many birders submit their lists to the American Birding Association, a nonprofit organization dedicated to recreational birding. The recording rules are simple: Species must be alive, wild and unrestrained. They must also be on the ABA checklist. This includes breeding species, regular avian visitors and rare species that stray from their range, as long as they stray without human assistance.