Chimney Swift in flight

The chittering sounds of the Chimney Swift will return to Wisconsin from mid-April to early May as the birds return from their winter homes in South America. While migrating through the state, large numbers can be found in the early evenings -- ready to roost in brick chimneys. Some will stay in the area to breed, and others will go farther north.

“Springtime is an excellent opportunity to gauge swifts' population numbers and help assess trends for this species,” said Barbara Duerksen, member of the Wisconsin Chimney Swift Working Group, a statewide volunteer effort to keep swifts common in Wisconsin. “Counting swifts is important, because their numbers are declining. We’ve been doing this for years in the fall, but we’re now encouraging folks to be watching and counting in the spring as well.”

Unfortunately, according to the latest North American Breeding Bird Survey, the Chimney Swift population has declined by 72% in the past 50 years. By continuing to monitor these populations, the working group hopes to learn more about them and identify important roost sites, so ways to protect them can be found.

“Everyday people like you and me 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 to do this. All you need to do is count.”

In addition to being valuable and fun, a spring count 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.

Here's how to help with the spring count:

  1. Watch and listen for Chimney Swifts during the daytime as they hunt for insects to determine when to begin counting. The lower half of the state may see the birds from late April to early May. Swifts may reach the upper half of the state a little later.
  2. Look for tall brick chimneys that are uncapped. If you find more than one chimney, do some scouting in the evenings to determine where the swifts will roost. Watch for swifts swooping over the chimney for a while before they enter. Be aware that the roost site choice can change from night to night, especially during migration.
  3. Pick one or more nights to monitor in May. Larger numbers show up two or three weeks after the first swifts arrive.
  4. Observe the roost from about 20 minutes before sunset until 10 minutes after the last swift enters the chimney. Please stay in one location, even if you do not see swifts right away. They may come to your site later, and you do not want to miss them. To be sure, stay 30 minutes after sunset to know if the chimney was active or not. If you have zero swifts in your chimney, please record this; this is still valuable information.
  5. 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. A hand-held clicker counter can be helpful.
  6. Counts could continue at the large chimneys throughout the breeding season, if large numbers of individuals continue to use these roost sites.

You can help the working group access and utilize your data by entering it on eBird. When prompted for location, map your roost site to an exact address or point. After you enter the number of Chimney Swifts, please use the hash tag #swiftwi in the Chimney Swift details section. This step helps working group members access your information quickly.

You can also take it a step further by adding information in the Chimney Swift details section. Please do so in this exact order, with semicolons separating the data: #swiftwi; the type of building (residence, school, church, business, hospital, apartment, swift tower/structure, etc.); the condition of the chimney (in good shape; in need of repair); any other notes (for example: #swiftwi; residence; chimney in need of repair; any other notes).

“It’s pretty easy for anyone to identify a Chimney Swift: They have slender bodies, with long, curved wings and a short, tapered tail -- they look like a flying cigar,” said Duerksen. They fly rapidly, often twisting from side to side and banking erratically. They also give a distinctive, high chittering call while in flight. Chimney Swifts are the only bird that will roost in a chimney, dropping inside at dusk and emerging the next morning.

More information about Chimney Swifts and how to help protect them locally is available from the Wisconsin Chimney Swift Working Group.


Read more:

Chimney swifts are disappearing in Wisconsin; fixing up your home is one way to help (Milwaukee Journal Sentinel, July 14, 2020)

Resources for Chimney sweeps and masons

Chimney Swift (All About Birds)

Wisconsin Chimney Swift Working Group

Bird City Wisconsin recognition criteria