There’s a “meteoric rise in the numbers of turkeys we’ve been finding lately,” says Jacco Gelderloos, who compiles local data for the Audubon Christmas Bird Count.

The count has been going on for 114 years, making it the longest-running citizen science survey in the world. Washtenaw County birders have taken part since 1940, but the volunteers didn’t see a single turkey until 1989. Last year, they counted forty-three.

“There are a number of species that you think of as common that really didn’t used to be,” says Gelderloos, such as northern cardinals, southeastern birds which were rare in the 1960s and are now seen in the hundreds during the CBC, as are red-bellied woodpeckers and, in much smaller numbers, Carolina wrens.

What birders are seeing in Ann Arbor reflects national trends. Based on CBC data from the past forty years, 200 North American bird species have shifted their range northward an average of thirty-five miles due to warmer temperatures. Helped by a reintroduction program and their ability to live near developed areas, wild turkeys are now found 400 miles north of their former range.

On December 21, about seventy volunteers will count every bird they see or hear within a fifteen-mile circle of Maple Road and Huron River Drive. Mike Sefton, one of the area leaders, has devoted the third Saturday in December to the CBC for the past fifteen years. Asked why, he talks about the thrill of finding unusual birds and the importance of the CBC’s population data to conservationists. While turkeys are increasing, development and reforestation of open fields have reduced the numbers of grassland species such as northern bobwhite and ring-necked pheasant. More mature forests, on the other hand, have probably contributed to the arrival of pileated woodpeckers, first counted here four years ago, and the barred owl, which has been seen at other times but not yet recorded on the CBC.

Another area leader, sixteen-year-old Sarah Toner, will be out at 6:30 a.m. looking for owls before the main count. She started birding eight years ago after hearing a talk by a local naturalist. She is one of six dedicated local young birders who are eagerly sought after by the more mature counters, partly for their better eyesight and hearing. While Washtenaw Audubon may be a little top-heavy in geezers, it encourages young birders by providing rides when their parents aren’t participating, treating them as equals, and giving scholarship money for birding camps. Sefton makes it a point to pair experienced birders with newcomers and designs routes to maximize sightings.

At the end of the day, everyone gathers at a potluck to share stories, get warm, and turn in their data. Last year, they spotted 25,875 birds from seventy-eight different species; this year, they’d like to do better.