Now is the Time to Help Count Chimney Swifts

Citizens’ reporting on evening phenomenon may help protect a declining species

MADISON, WI – That “smoke” pouring into brick chimneys in coming weeks isn’t an optical illusion but likely hundreds of native chimney swifts roosting for the night and gathering strength and numbers before they migrate south, all the way to the Amazon.

Wisconsin bird experts are asking homeowners, bird watchers and others to help count the birds and report where they see them to provide vital information on a declining, unique species.

“Chimney swifts are an important species in Wisconsin because they help keep flying insect populations in check,” says Kim Grveles, Department of Natural Resources avian ecologist and a member of the Wisconsin Chimney Swift Working Group. “We need citizens’ help in counting the birds near them, and in reporting that information to us so we can better understand and take steps to hopefully reverse the decline of chimney swifts.”

“You don’t have to be an experienced bird watcher or trained researcher to enjoy the evening aerobatic displays of the swift,” says Nancy Nabak, co-chair of Green Bay’s Swift Night Out program and member of the Wisconsin Chimney Swift Working Group. “The sight of dozens or hundreds or, in some cases, thousands of chimney swifts going to roost for the night in chimneys can be an exhilarating spectacle.” Click here for a list of local Swift Night Out events.

The Wisconsin Chimney Swift Working Group (www.wiswifts.org) formed in 2012 to help identify and protect important swift roost sites, encourage or conduct field research on swifts and their ecology, and educate the public about the species in order to encourage action to halt the species’ decline. “Modern construction often doesn’t include chimneys, and chimneys are critical as nest sites and for communal roosting for non-nesting swifts. We want to encourage the public to keep suitable chimneys uncapped to provide habitat for these amazing birds,” says Sandy Schwab, chair of the working group.

In the last few years more than 60 volunteers have helped identify more than 72 chimney swift roosting sites across several urban areas. One of the largest known swift roosts is the chimney at Cherokee Middle School in Madison, where more than 2,800 swifts were tallied in 2012. Aldo Leopold School in Green Bay, St. Norbert Abbey in DePere, and Geneva Lake Museum in Lake Geneva are sites of other large roosts.

Cherokee Middle School, Madison, WI – Video by Christina Ciano

Chimney swifts nest in eastern North America in the summer and migrate to South America in the fall. Before European settlement, the birds nested in old-growth forests. As such forests disappeared, the birds discovered brick chimneys served as an easy and abundant replacement, Schwab says. Brick chimneys work well for the birds because the chimneys provide enclosed areas with a rough, vertical surface the birds can cling to, much like a hollow tree. Unlike most birds, chimney swifts do not perch on branches or other horizontal surfaces but must use the sharp nails on their tiny feet to cling to vertical surfaces.

For years their populations have been in decline, and in 2009 Canada listed them as a threatened species. Why are they declining? No one knows for sure, but scientists want to conduct more research on the insects chimney swifts eat to better understand if changes in flying insect populations, possibly driven by widespread pesticide use, might be adversely affecting chimney swifts and other “aerial insectivores” such as whip-poor-wills, nighthawks, and swallows.

Tips on how and where to look for chimney swifts - click to expand

Chimney swifts have slender bodies, very long, narrow, curved wings and short, tapered tails. They fly rapidly, with nearly constant wing beats, often twisting from side to side and banking erratically. They often give a distinctive, high-pitched chattering call while they are in flight, said Bill Mueller of the Western Great Lakes Bird and Bat Observatory, Belgium, WI, and an advisor to the working group.

“A lot of folks see and hear them in the evening and don’t realize they’re birds,” he said. “They think they’re bats.”

Because chimney swifts congregate in communal roosts before migrating in late summer/fall, it’s relatively easy to count them. Here’s how to count:

  1. Look for tall brick chimneys that are uncapped. Watch to see where swifts are feeding and congregating. Pick one or more nights from early August in northern Wisconsin through mid- to late September in southern Wisconsin. Observe the roost starting about 30 minutes before sunset until 10 minutes after the last swift enters the chimney. Count (or estimate) the number of swifts as they enter the chimney. It’s useful to count in groups of five or 10 birds at a time when many birds pour into the chimney in a short period of time.
  2. Send in data one of two quick and easy ways.
    • Enter the data on eBird (preferred). Go to the ebird-quick-start-guide. When prompted for location, map your roost site to an exact address or point. Include, in the “Chimney Swift” comments section, general weather conditions, time when the first and last swifts entered the roost and type of building — residence, school, church, business, etc.
    • Or send the same information as above along with your name, address, email address, date and exact time of your survey at the roost to Sandy Schwab, 105 S. Marietta St., Verona, WI  53593 or sschwab49@gmail.com (Request a report form by emailing sschwab49@gmail.com)

FOR MORE INFORMATION CONTACT: Sandy Schwab, Wisconsin Chimney Swift Working Group, 608-658-4139

What is a Chimney Swift?

Basic ID

Chimney Swifts are dark gray-brown, swallow-like birds with long, slightly curved wings and stubby tails.  They fly with stiff, rapid wing beats.  Their call is a series of quick, chittering noises.

More information:


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Chimney Swift in FlightThis small bird spends almost its entire life in flight, feeding and drinking on the wing.  Chimney Swifts nest and root in chimneys and on vertical surfaces in dim, enclosed spaces.  On migration in spring and fall, swifts can be seen at dusk swirling into large chimneys by the dozens or even thousands to roost for the night.

Click here to learn more and watch a video of Chimney Swifts.

Why Care About Chimney Swifts?

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  • Chimney SwiftChimney Swifts have declined significantly in recent decades and need our assistance more than ever. In 2009, our northern neighbor, Canada, listed them as Threatened.
  • Because of changes made to our landscape and loss of historical habitat, swifts rely almost entirely on man-made structures for nest and roost sites. Our chimneys are their homes.
  • Chimney Swifts eat up to half of their own weight in flying insects, including pests, every day.
  • Chimney Swifts are protected by Federal law under the Migratory Bird Treaty Act of 1916.
  • Like watching a beautiful sunset, the aesthetic value of observing Chimney Swifts’ aerial acrobatics and interactions is a simple pleasure of nature.

How Can I Help?

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  • Baby Chimney SwiftIf you have a masonry or clay flue-tile chimney, keep the top open and the damper closed from April through October to provide a nest site for these insect-eaters. Metal chimneys should be permanently capped to prevent birds and other wildlife from being trapped.
  • If you have your chimney cleaned, do it from November to March before the Chimney Swifts return from their winter home in South America.

To find out how you can help this amazing species, visit this page.



Keep Chimney Swifts common in Wisconsin