MADISON, Wis. – The Wisconsin Department of Natural Resources (DNR) and the Wisconsin Chimney Swift Working Group are seeking volunteers to participate in Swift Night Out to count chimney swifts between mid-August and early September.

Monitoring chimney swift populations helps us identify important roost sites and find ways to protect them. Chimney swifts, a unique bird species that nests and roosts in chimneys, are beginning to migrate south, all the way to the Amazon, starting in mid-August.

Once dependent on cavities in standing dead trees, swifts now rely on manufactured structures, like chimneys, for nesting and roosting. This transition to chimneys began as forests were cleared and standing dead trees removed. Fewer structures now have usable chimneys, which could be a driving factor in the species’ decline. According to the latest North American Breeding Bird Survey, the chimney swift population has declined by 72% in the past 50 years.

During migration, something special happens: They become communal. They often gather at dusk in great numbers, occasionally in the thousands.

“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.”

How To Identify Chimney Swifts

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 wing beats, often twisting from side to side. They also give a distinctive, high-pitched chittering call while in flight. They are the only birds that will drop into chimneys to roost for the night. Bats may use chimneys to roost during the day but exit in the evening.

How To Count

  • From mid-August for northern Wisconsin to early September in the southern part of the state, look for tall, uncapped brick chimneys. Watch for swifts swooping and circling near a chimney to determine if they might roost there.
  • Observe the birds entering the chimney about 20 minutes before sunset until 10 minutes after the last swift enters the chimney. Stay in one location, even if you do not see the swifts right away. They may come to your site later. If you have zero swifts entering your chimney, please record this. This is still valuable information.
  • Count (or estimate) the number of swifts as they enter the chimney. It’s useful to count in groups of 5 or 10 when they enter quickly in large numbers. A hand-held clicker counter can also be helpful.
  • Enter your data on eBird, with a free eBird account by following the instructions. Data sharing is a critical piece of this activity to allow swift conservationists to access your count data!

Learn more about chimney swift biology, migration and conservation needs during a free, online presentation “Mighty Migrations: The Chimney Swift” featuring speaker Dr. Steffanie Munguía at 7 p.m. on Aug. 19.

For more information on chimney swift identification, how to protect them or to find a Swift Night Out event near you, visit the Wisconsin Chimney Swift Working Group website.