Chimney Swift Overhead - Photo Jim Mcculloch

Chimney Swifts

Chimney Swift Pair in Flight - Photo Paul and Georgean Kyle
Chimney Swift Pair in Flight – Photo Paul and Georgean Kyle

I am curious about all native cavity nesters, including Chimney Swifts. In the last summer, when most birds are slowing down their nesting activities, I am listening to the chitter and twitter of Chimney Swifts. I will never get to see their nest except in pictures, as they all pair off and nest in chimneys. There is a cap on my condo chimney, but I have heard nesting young in other chimneys – and they are loud for a couple weeks.

But something special happens with Chimney Swifts after they fledge from their nesting chimneys. Starting in mid-July and continuing into very early October, they do what is called staging.  At dusk, birds gather from all directions and fly in a general clockwise flight, with the circle getting tighter and tighter, for ten to fifteen minutes or so. Then, just after sunset as the light is fading, they start to enter a chimney to roost for the night. The chimneys that the swifts use usually are tall stacks at a school or large industrial site. We often say it looks like the swifts are being sucked into the chimney or like reverse chimney smoke!

As observers, we count how many swifts enter the roost site. We are doing citizen science: we gather the data and submit it.

While I am not an expert on Chimney Swifts, I have done a lot of research and have talked to a few real experts. Before European settlement, swifts used to nest in tree cavities, but they had to adapt and change their practice to survive deforestation. These days, it’s not easy to find a natural cavity that holds Chimney Swifts.

My passion and interest with this insect-eating native species is to make more people aware of the declining Chimney Swifts and take some action to try to help the species before they vanish. In a recent National Geographic article, Chimney Swifts are described as “near threatened and decreasing in population”. I can only imagine that deforestation has played a large part in their decline, along with capped chimneys and the deplorable condition of old industrial chimneys. While many people cap their chimneys at home for various reasons, capping of larger chimneys has eliminated many roost sites.

By the way, Chimney Swifts breed north into Canada and east of the Rockies in the United States, then in the fall migrate south all the way to the Amazon basin of Peru. They look for staging chimneys all along their migration routes. Some fun facts:

  • They often are called “flying cigars” due to their shape
  • Swifts never perch but cling onto rough chimney walls facing upward. In fact, they cannot stand, perch or walk on the land.
  • Swifts eat, sleep, and even mate on the wing. Pretty amazing!

You can learn more about Chimney Swifts at Audubon’s online Guide to North American Birds. National Geographic’s Web site has additional details, and Cornell’s All About Birds Web site gives some very good information too.

A July Night for Swifts

SwiftsOn July 10th, 2017, I and my bluebird friends, Paula Ziebarth and Sue Guarasci, had just finished dinner in downtown Dublin when I said “Look, there are swifts above, let’s see what’s happening at Sells Middle School.” Before I describe what we saw, here’s a little history: Sells Middle School is on the north side of OH 161, east of Frantz Rd and west of Dublin Rd.) I had discovered the staging site 15-plus years ago, and have enjoyed using it as a setting to making others aware of these amazing creatures and their important use of tall chimney stacks close to dusk.

Back to our July evening: We made it to the school at about 9:00 pm and we quickly parked so that we could watch the swifts. Just a few swifts, maybe eight, were flying over the building. But we were not disappointed tonight; in fact, we were quite surprised while counting the birds as they were entering the chimney. They kept going in and by 9:50 we had counted over 675 birds entering the chimney for their evening roost – and that’s only July 10! At this early summer date, we thought we would be lucky to see 25 or so birds.

The 2017 Nesting Season

Chimney Swift Adult with Young - Photo Paul and Georgean Kyle
Chimney Swift Adult with Young – Photo Paul and Georgean Kyle

As an avid conservationist working with Eastern Bluebirds, Tree Swallows, Purple Martins and American Kestrels using state of the art housing, I and many other monitors have noticed that 2017 has been an amazing nesting season with many birds being fledged. Bluebirds have started their third nesting (brood) for the year in central Ohio. In some areas, the availability of cicadas may have helped, but that is only for a few weeks and not all parts of Ohio have cicadas. In any case, we can now add Chimney Swifts to the list of insect-eating birds doing very well so far this season. Indeed, I have never seen this many birds staging this early in the fifteen years I have been watching them.

Citizen Science

When it comes to Chimney Swifts, I’m a Citizen Scientist – and you can be, too. Citizen scientists collect date that can help professional scientists in their research; for swifts, we enter data at There are special times to do so, referred to as Swift Night Out. The process is to watch near dusk on one of the designated days, listening for the sound of swifts twittering and chittering as they fly around a chimney. When the swifts start entering the chimney, note the start time (when the first swift flies in), count the swifts entering the chimney, and then note the end time (when the last swift enters). Finally, you enter your chimney location and count data on an easy-to-use form on the Web site. By the way, counting fast-moving birds in low light is trickier than it sounds, but don’t worry: it’s OK if you are off by a little bit.

How many birds might you see? About twelve years ago, the high counts at Sells Middle School were over 5,000 swifts entering the chimney! This YouTube Video shot by my friend Glenn Snow will give you a sense of the show you will see.

When and Where

Delaware's Ohio National Guard Armory, built in 1920, stands with it steel rafters exposed as it awaits the next stage of demolition. An air shaft at the north end, and a brick chimney the opposite end, had sheltered roosting swifts for many years.
Delaware’s Ohio National Guard Armory, built in 1920, stands with it steel rafters exposed as it awaits the next stage of demolition. An air shaft at the north end, and a brick chimney the opposite end, had sheltered roosting swifts for many years. What will replace it now?

This year, Swift Nights Out are August the 11, 12, and 13 and September 8, 9, and 10. For both sets of monthly counts, I will visit Sells Middle School. But there are other locations in the Columbus area, including schools in Clintonville and buildings in Delaware County. (We have a list of known locations here.) Look up the time of sunset (try and try to go 30 – 45 minutes or more before then to watch the birds come in. If it is a cloudy and overcast night, the birds will start entering the chimney sooner.

Take some time and look for sites in your neighborhood in old school or business chimneys.  Take time to report your findings and get others excited to watch the swifts. Or take it a step further and get involved in a swift tower conservation project!  Several are going up in the central Ohio area later this year. Check the Columbus Audubon Events Calendar for several Swift Night Out public programs. Bring your lawn chair (and some mosquito repellent, just in case:  you’ll enjoy the free show.

Still More Information

Explore the Chimney Swift pages on the Columbus Audubon Web site using the menu to the right. Be sure to check out where to see Chimney Swifts in central Ohio.

Paul and Georgean Kyle, swift experts at, have authored two books, one on species Chateura pelagica and one on building swift towers. They have been a terrific resource to answer my many questions.

On Tuesday October 24, 2017, Columbus Audubon presents one of their monthly programs featuring Judy Semroc, Conservation Specialist with the Cleveland Natural History Museum and an Ohio Bluebird Society expert. She has a fantastic presentation about Chimney Swifts – and she has erected a swift tower on her property with nesting success, just as we will do in the central Ohio area. See the program entry on the Columbus Audubon Events Calendar for details. (While you’re there, check out Columbus Audubon’s other monthly programs, too.)

Wrapping Up

Now go out and listen near dusk. Find a chimney that your neighborhood swifts are using, count them, and enter the data on What a great family project for kids of all ages to take part in!

Darlene Sillick is an Ohio Bluebird Society trustee and Franklin County area contact. She also serves on the Ohio Ornithology Society and Columbus Audubon conservation committees.