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Audubon Action Center

©2016 Northeastern WI Audubon Society, Inc.


Summary for A Swift Night Out-Green Bay

2011 -- 2012 -- 2013 results

Can't Make a Swift Night Event? Count on Your Own

Since swifts congregate in communal roosts prior to their migration in late summer/fall, it's relatively easy to count them.
Here's how to count: Look for likely chimneys (uncapped, tall, and brick so the swifts can cling to the interior)– especially on large buildings such as schools, churches, or factories. 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 (often when it's so dark it's hard to see anymore). Count or estimate the number of swifts that enter. Count in groups of 5 or 10 when they enter most quickly.
Collect data.Identify your site by an exact address or GPS point (lattitude/longitude). Note general weather conditions, time when the first and last swifts entered the roost, what type of building it was (residence, school, church, business, etc), and any other interesting details.
Send data. Email the coordinator nnabak @ sbcglobal.net or mail results to us at PO Box 1, Green Bay, WI 54305. Don't forget to include your contact info in case we have any questions.

Dates:Count taken on August 10, 2013. 2,526 swifts observed flying in the area of chimneys.  1,624 swifts were actually seen entering the roosting sites.  

Dates:Count taken on August 4, 2012. additional sites checked between 7/25 and 8/10.

Location: Green Bay, Wisconsin


  • Over 30 volunteers participated
  • 1088 Swifts were counted entering chimneys
  • 1563 Swifts were seen flying about
  • 14 sites were monitored on August 4 with 45 additional sites monitored during the extended time period
  • Swifts were seen entering 37 chimneys and Swifts flying around (but not seen entering) an additional 8 chimneys.
  • 4 chimneys had more than 70 Swifts entering, 20 had 6-70 Swifts, and 13 chmineys had 1-5.

Date:  Count taken on August 6, 2011. followed by September

Location:  Green Bay, Wisconsin


  • 31 people participated
  • 227  Swifts were counted entering chimneys
  • 570 swifts were seen flying about
  • Swifts were seen entering chimneys from 6:30-8:00pm, Central Daylight Savings Time, but most entered chimneys between 7:50 and 8:00pm.CDST
  • Swifts entered chimneys early because of rain at 8:00pm
  • School, church, residential, and small commercial chimneys were used, no large industrial chimneys were used
  • 18 sites, some with 2 or 3 chimneys were checked for swifts.
  • 12 chimneys were used by swifts, 7 chimneys had 6-70 swifts enter, 5 chimneys had 1-5 enter, at least 2 of these were active nest sites
  • This spring was very cold and late so some swifts might have started nesting late


Additional sites were checked earlier, one each on Aug. 3 and Aug.4. 
50 Swifts total were seen entering chimneys on those two nights. And on Aug.7,  12 swifts were counted entering 2 more chimneys with about 75 swifts flying about. 

Weather:   80 degrees dropping to 70 by 8 pm,  wind- 0-5mph from east, 6-7:45 pm then 5-25mph from west at 7:45 pm, clear at 6 pm with a fast incoming storm at 7:45 pm, rain at 8 pm. Swifts entered chimneys early because of rain.  Sunset at 8:12 pm.

Most participants were members of the Bay Area Bird Club or Northeastern Wisconsin Audubon Society.  This survey was a Bird City Green Bay and a Bird County Brown County event.  Bird City Green Bay sponsors include: NEW Audubon Society, Bay Area Bird Club, Baird’s Creek Preservation Foundation, Bluebird Restoration Association of Wisconsin, Bay Beach Wildlife Sanctuary, Cofrin Center for Biodiversity UWGB, Downtown Neighborhood Association, Izaak Walton League of Brown County, Sustainable Green Bay Task Force, Green Bay Botanical Garden, and the Green Bay Chapter of the Wild Ones.  Bird County Brown County sponsors include:  Neville Public Museum of Brown County, Brown County Parks, Brown County Port & Solid Waste, Brown County Land Conservation, Barkhausen Waterfowl Preserve, University of Wisconsin Extension, and Brown County Planning Department.

Survey Coordinators:   Mike Reed, Director, Bay Beach Wildlife Sanctuary
John Jacobs, Curator of Science, Neville Public Museum of Brown County,
Nancy Nabak, Bird City Green Bay

September 10, 2011, Green Bay, WI 


  • 18 people participated, 22 sites, some with 2 or 3 chimneys, were checked for swifts.
  • 115  Swifts were counted entering chimneys
  • 4 chimneys were used by swifts,  One chimney had 100 swifts enter.  Most of the swifts seem to have left the Green Bay area by this date.
  • Swifts were seen entering chimneys from 7:20-7:42pm, CDST
  • Weather: mid 70’s during the day dropping to 72 degrees by 7 pm,  Clear and Calm.

Additional sites were checked between August 7 and September 9 in the Green Bay area.  6 people checked 30 sites (chimneys) most of these did not have swifts. Those that did included a private home- 5 swifts; church-11 swifts; school-12 swifts; monastery- 236 swifts; Greenhouse- 47 swifts; school- 15 swifts.   Total=  326 swifts for this timespan.










P.O. Box 1, Green Bay, WI 54305