Madison Reporter

The Wisconsin Department of Natural Resources (DNR) and the Wisconsin Chimney Swift Working Group are inviting community members to take part in an effort to monitor chimney swift populations as the birds begin their fall migration. The initiative, called Swift Night Out, will run from mid-August through early September.

Chimney swifts are small birds known for nesting and roosting in chimneys. Historically, these birds relied on cavities in standing dead trees, but with forest clearing and the removal of such trees, they have adapted to using man-made structures. Now, as fewer buildings maintain suitable chimneys, there is concern that this reduction in habitat is contributing to a decline in the species’ numbers. According to recent findings from the North American Breeding Bird Survey, chimney swift populations have dropped by 72% over the past five decades.

During their migration south toward the Amazon basin starting in mid-August, chimney swifts exhibit communal behavior by gathering at dusk—sometimes in groups numbering into the thousands—to roost together. These gatherings often occur around tall brick chimneys found on schools or churches.

“It’s not unusual to see swifts circling and swirling over a school chimney or an old church chimney just before dusk in the middle of August or September in Wisconsin,” said Rich Staffen, Wisconsin DNR conservation biologist and co-chair of the Wisconsin Chimney Swift Working Group. “But data indicates that it’s less common than it used to be. Anyone can count chimney swifts as they enter chimneys in the early evening. It’s a simple process; you don’t need to be a bird expert. All you have to do is count individuals going into a chimney.”

The public is encouraged to look for these birds between mid-August (in northern parts of Wisconsin) and early September (in southern areas). Observers should find tall, uncapped brick chimneys where swifts may congregate at sunset. Volunteers are asked to watch about 20 minutes before sunset until 10 minutes after the last bird enters the chimney, recording both sightings and instances where no birds appear.

Identifying a chimney swift involves looking for its slender body, long curved wings, short tail—often described as resembling a flying cigar or boomerang—and listening for its high-pitched chittering call while it flies with quick wing beats and twisting motions. Unlike bats—which use chimneys during daylight hours but leave at night—chimney swifts drop into chimneys at dusk specifically for overnight roosting.

Those who participate are asked to count or estimate how many swifts enter each chimney location and submit their data via eBird after creating a free account on that platform (https://ebird.org/). This information supports ongoing research efforts aimed at conserving remaining populations by identifying important sites across Wisconsin.

In addition to participating in counts, residents can learn more about these migratory birds during a free online presentation titled “Mighty Migrations: The Chimney Swift,” featuring Dr. Steffanie Munguía on August 19 at 7 p.m.

Further resources on identification tips, conservation practices, and event locations can be found through the Wisconsin Chimney Swift Working Group website (https://www.wiswifts.org/).