Report Chimney Swift Nest & Roost Sightings

chimney swift © Shawn P. Carey, Migration Productions

Throughout most of their range chimney swifts are declining. This chatty, enigmatic summer breeder needs our help.

During the 43,000 hours spent surveying birds in Massachusetts for the Breeding Bird Atlas 2, not one nest or roost site was found in a natural cavity (think a big dead tree)—they were all in chimneys.

Help us to map chimney swift spring and fall roosting as well as summer nest sites in the US and Canada. Saving their nesting and roosting sites may be a key to slowing or stopping their rate of decline.


The chimney swift is the only swift found on the East Coast. Said to look like a flying cigar, the sooty gray chimney swift has a short body (4½-5½ inches) and wings that are narrow, slightly curved, and a spread of 12 to 13 inches. In flight they appear almost bat-like with rapid, erratic wingbeats, interspersed with short, quick glides. As they fly through the air, swifts make a loud, chattering or twittering call.


Chimney swifts roost in groups year-round; in North America roosts may be occupied from late April to early September. Roosting behavior and locations in their wintering grounds are unknown, and any observations from your winter birding trips to South America will have huge conservation value! Breeding takes place from late May through early August.

Roosting swifts become very obvious in the early evening. You will maximize your chances of actually seeing them go into a chimney if you watch during the 1/2 hour after sunset (the time the sun dips below the horizon).


Everywhere there are chimneys! We want to map roosting and breeding sites across the US and Canada. Swifts are urban critters, so this is a perfect project for urban dwellers. They also like big chimneys for roosting, especially old factories and schools.


Chimney Swift nest & eggs © Shawn P. Carey, Migration Productions
Chimney Swift nest © Shawn P. Carey

To monitor a roost site, please watch a “suspicious” chimney for at least 30 minutes—longer if possible. Remember, if you watch right around sunset (15 or 20 minutes before and after sunset) you are most likely to see birds entering the roost!

Breeding swifts will go in and out all day long—that is very hard to spot, but extremely important data. Homeowners know when they have swifts around the house, and a sharp eye outside, as well as careful listening indoors, may tip you off to breeding.

If you locate a swift roosting or nest sight, please report in via our Mapping Tool:

  • Sign in to the mapper tool. An account is created for you so you can come back later and tell us more about your swift sightings.
  • Place the map locator as precisely as possible over the nest or roost site.
  • Fill in the questions.
  • Revisit the site if you think it was an active roost or nest site – even report a visit if you do not see swifts.
  • Come back and fill in the mapper again (and again and again). More data is always better.
  • To fill in the question about the interval between feeding listen for an arrival (noisy chattering), set a stopwatch, and wait for the next feeding.

Additional Resources

Learn more about chimney swifts and what do if you're concerned about a nest in a chimney.

Project Partners

This project is a partnership with Mass Audubon, Connecticut State Ornithologist Dr. Margaret Rubega at the University of Connecticut, and Dr. Andrew Vitz, the Massachusetts State Ornithologist at Massachusetts Division of Fisheries and Wildlife.