When I tell people I’m a swiftie, they ask what is my favorite song. While I like many of Taylor Swift’s songs and I admire all she has accomplished, I’m not talking about her. I’m talking about the unique and spectacular bird, the chimney swift.
I had never witnessed the magical display of chimney swifts gathering at sunset to circle and slowly descend into a chimney to roost for the night. So, when I heard the Wisconsin Natural Resources Foundation offered a field trip called A Night Out With the Chimney Swifts, I was quick to sign up. Before that night arrived, I decided to learn all I could about this remarkable bird.
Chimney swifts are grayish-brown with thick cylindrical bodies, a very short neck, round head, no discernible tail, and short, stubby bills, earning them the nickname “flying cigars.”
According to All About Birds, in flight, their wings are shaped like a boomerang. Their long wingtips allow them to fly rapidly, with stiff wing beats, often twisting from side to side and banking erratically as they give a loud chittering call.
I was amazed to learn that chimney swifts continuously fly all day long never stopping except to nest and roost overnight. They do everything in flight. They eat flying insects, bathe, collect nest material and even mate in flight.
According to the National Audubon Society, they eat as many as 12,000 insects in a single day, a third of their body weight. To build a nest, chimney swifts use their feet to snap off twigs in mid-flight. Then they use their saliva to glue them together to form a half-cup nest inside the chimney. Nests can consist of over 250 twigs.
Chimney swifts are not able to perch like other birds. Instead, their toes and nails have a unique structure allowing them to cling to vertical surfaces. The tail feathers have 10 stiff spines that also help to support them.
Interestingly, unmated swifts share a chimney, but mated pairs each nest in their own chimney. After the young fledge, parents and young join staging flocks in bigger chimneys nearby, hundreds, sometimes thousands, in a single chimney. According to All About Birds, during migration as many as 10,000 swifts roost together on their journey to South America.
When the time came for the field trip, I felt excited and prepared to experience the ceremony of the swifts coming in to roost for the night. We met at a library whose chimney had recently been an active roosting site.
However, upon arrival, our tour leader Spence Stehno, president of the Benjamin F. Goss Bird Club, announced that the swifts had changed locations to a chimney down the road. He explained that it is hard to predict when they will move on and how far away each move will be from the previous location. It is equally hard to tell if the swifts are the same ones from the night before or new ones.
Just before sunset, one by one, two by two, then 10 by 10 they appeared, dark silhouettes circling high above the chimney. Erratically, they slowly lowered as the circle got smaller and smaller, tighter and tighter. I could hear the chittering growing louder as my heart pounded to the beat. I could feel my cheeks lifting as my lips stretched into a wide grin. This is it. They are doing this and I am here to witness this amazing display of nature at its best.
There weren’t enough swifts to make a tornado-like funnel, but counting observers estimated 180 birds circling and descending into the chimney, first the scouts, then the rest, some feet first, some head first. It was a night I will never forget.
I hope others can experience this, too, but the chimney swift population is in steep decline. Chimneys are being torn down or capped and not being replaced. According to American Bird Conservancy’s “State of the Birds” report, between 1970 and2019, Chimney Swift population has dropped 50%.
People can help by preserving existing chimneys or creating new structures specifically for swift nesting. Designs can be downloaded from the North American Chimney Swift Nest Site Research Project.
Another way to help is to go see these birds for yourself and then spread the word. The best time in Wisconsin is September to mid-October. Look for uncapped chimneys on older buildings like churches, schools, factories, or historical structures. According to eBird, there were many swift sightings in this readership area this year. It is free and the whole family can join in to behold this phenomenon and share in the marvel of the chimney swift.
I’m a swiftie. I hope you become a swiftie, too.
Lisa Jansen is a Wisconsin master naturalist, nature writer, and award-winning photographer. She specializes in raising awareness of birds and butterflies of the Midwest.
Swifties turn their attention to birds
