Chimney Swifts drop into a chimney at dusk

This article was submitted by the Wisconsin Chimney Swift Working Group.

You are invited to a free evening concert in nature. The performers are the Chimney Swifts, and they will be chittering and twittering above chimneys in the evening sky before they roost for the night this fall.

The birds are getting ready to migrate south, all the way to the Amazon, and when they do, they become communal. This is where the show begins. Some sites may consist of a half-dozen swifts or so, but the larger sites can host hundreds or even thousands of swifts.

“Volunteers all over the state of Wisconsin have counted thousands and thousands of swifts roosting in chimneys over the past decade,” said Nancy Nabak, chair of the Wisconsin Chimney Swift Working Group. “It’s fascinating to watch, count, and listen to swifts as they circle and whirl above chimneys before they roost for the night -- it’s a visual sky concert.”

The statewide group is asking birdwatchers and local community members to help count swifts entering chimneys at dusk from mid-August through September, depending on where you are in the state. This is part of a continent-wide program called Swift Night Out held to raise awareness about the declining federally protected species.

Golden opportunity for Bird Cities

In addition to being valuable and fun, counting swifts represents a golden opportunity for Bird Cities and communities that would like to be recognized as a Bird Cities to satisfy one of the program's recognition criteria. Communities can do this either by sharing the results of Chimney Swift counts or other organized bird monitoring in the local park system (Category 1: Habitat Creation, Protection, and Monitoring), or by demonstrating that the community is represented in a citizen science bird-monitoring program such as a Swift Night Out (Category 4: Public Education).

See Bird City's recognition criteria.

Nabak said that although volunteers have counted large numbers of swifts since the program began, they’ve also documented the loss of many chimneys due to demolition or capping, resulting in a loss of habitat for the bird. This is a trend that the group hopes to bring to the forefront, finding ways to protect existing chimneys.

Last year, the group created a partnership with the US Fish and Wildlife Service to preserve swift chimneys in need of repair through a cost-share program. The Vernon County Historical Society was able to restore a chimney at the Vernon County Historical Museum in Viroqua, which hosts hundreds of swifts.

If you know of a chimney that needs repair and currently hosts swifts, please This email address is being protected from spambots. You need JavaScript enabled to view it..

How can you help? Anyone can go out just prior to dusk and watch swifts “drop” into chimneys as they roost for the night. All you have to do is count birds as they enter. Please note the condition of the chimney you are monitoring as well.

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 large hollow trees in old-growth forests. As these forests disappeared, the birds discovered brick chimneys as a replacement. Brick chimneys work well for the birds because they provide enclosed areas with a rough, vertical surface to which the birds can cling, much like a hollow tree. Unlike most birds, Chimney Swifts do not perch on branches but use the sharp nails on their tiny feet to cling to the sides of their roost.

According to the latest North American Breeding Bird Survey, the Chimney Swift population has declined 72 percent in the last 50 years. Specific reasons for the loss are unknown, but pesticides, climate change, and habitat loss all play a role.

How to recognize and count swifts:

Chimney Swifts have slender bodies with long curved wings and short stubby tails. (They look like a flying cigar or boomerang.) They fly rapidly with nearly constant wingbeats, often twisting from side to side. They also give a distinctive high chittering call while in flight. They are the only bird that will drop into chimneys to roost for the night. Because they congregate in communal roosts before migrating in late summer/fall, it’s easy to count them.

Here's how to count:

  • Look for tall brick chimneys that are uncapped.
  • Watch to see where swifts are feeding and congregating.
  • Pick a night to monitor from mid-August to September.
  • Observe the roost from about 20 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 5 or 10 when the birds enter quickly in large numbers.)
  • Enter your data on eBird if possible, and add #swiftwi in the species comment section. This helps researchers quickly track swift activity in Wisconsin.

For more information, visit the website of the Wisconsin Chimney Swift Working Group.


Read more:

Wisconsin Chimney Swift Working Group

About Chimney Swifts

Vernon County Historical Museum