By Jeremy Varner
Chimney swifts (Chaetura pelagica) are small, fast birds who spend most of their life cruising the sky. When I see them, they are typically up about tree-top level and zooming around while they eat all sorts of bugs.
Actually, I generally hear them before I see them. Their normal call is a series of short, sharp chirps, but it took practice to recognize it. For a few years whenever I would use the Merlin app to identify bird calls, about every second or third time it would identify chimney swifts. I would start looking around for them, would eventually look up, and then see these small dark birds speeding through the sky while making cuts that Atlanta Falcons running back Bijan Robinson would be jealous of. After several summers I learned to pick out their chirp-chirp-chirp and look up quickly to see some spectacular athleticism.
Roger Tory Peterson’s bird guidebooks describe chimney swifts as cigars with wings. Their bodies are about 5-6 inches long with a wingspan about double that size. They are generally dark without remarkable colorations or markings. Barn swallows (Hirundo rustica) are the other common bird you could confuse with a chimney swift, but the swallows have their distinctive swallow tail and are much more colorful with blues, red, and creams.
Chimney swifts, like the rest of their swift relatives, spend their lives in the air and only come down to earth for breeding, nest building, and egg hatching. It sounds hard to believe, but every source I checked said the same thing. They just stay in the air, all the time. Helen Macdonald’s beautiful essay “Vesper Flights,” from their book of the same name, is about the evening and night flying of the common swifts (Apus apus) of Eurasia. It’s exhausting to think of constant movement and never sitting down for a spell. All the perching birds must think swifts are crazy.
When chimney swifts do come to ground, they do so only on vertical structures because their weak feet and legs do not allow them to perch or walk. Before Europeans came to North America, chimney swifts lived in old trees. But once Europeans started building chimneys, bell towers, and other similar structures, the birds really found their ideal nesting spots (and a new name). Today, chimney swifts nest almost exclusively in human-made environments. Something to ponder is that the same construction can destroy the habitats of several critters while making the perfect home for others.
Even a trained ornithologist is going to struggle studying a bird that does not stop moving, but that did not deter Althea Sherman. She was self-taught and, in 1915, built a tower for swift nesting and observation in National, Iowa. For the next 18 years she studied the birds’ mating and nesting. Sherman was the first person to write a detailed life history of the bird. For more on her and on chimney swifts, check out https://shermanswifttower.org.
