10 Enjoyable Information Concerning the Chimney Swift

In many cities east of the Rocky Mountains, the chattering calls of Chimney Swifts are as a lot part of summer season’s soundtrack because the cha-cha of sprinklers or ice cream truck jingles. Swifts lower a singular profile usually described as resembling a cigar with wings, however that’s removed from the one factor that units them aside.

From their uncommon anatomy to their nesting habits, Chimney Swifts are among the many strangest of our widespread avian species. The extra you find out about these fascinating birds, the extra probably you’re to turn out to be a hardcore, um, Swiftie. 

1. Chimney Swifts are amongst our most city birds. As their identify suggests, they nest in chimneys or deserted buildings, and also you’re most definitely to search out them in cities and cities with loads of such locations to take shelter. It’s a sample that started after European settlers constructed chimneys and different enticing nest websites throughout the panorama—together with wells, barns, silos, and outhouses—producing a inhabitants growth for swifts.

2. But it wasn’t at all times so. Before settlers lower down old-growth forests, swifts nested primarily in hole timber. In his Ornithological Biography, written within the 1830s, John James Audubon vividly described a large hollowed-out sycamore close to Louisville, Kentucky, the place, some 20 years earlier, he discovered what he estimated have been 9,000 swifts roosting. Audubon was there one morning when the birds started to exit the roost, and he “listened in amazement to the noise within, which I could compare to nothing else than the sound of a large wheel revolving under a powerful stream.”

3. These days Chimney Swifts rely closely on people to supply nesting and roosting websites, however their historic reference to timber lives on. In current years 1000’s of swifts have taken shelter throughout fall migration within the Davie Poplar, a virtually 400-year-old, partially hole tree on the campus of the University of North Carolina at Chapel Hill. Swifts additionally reportedly make use of hole, old-growth timber within the Amazon rainforest, together with chimneys and different human-built buildings.

4. Beyond that, not a lot is understood concerning the species in its nonbreeding territory, which incorporates components of Brazil, Chile, Ecuador, and Peru. Scientists say there’s an actual want for extra analysis to raised perceive this portion of Chimney Swifts’ life cycles, particularly since populations have plunged by greater than 50 % over the previous 50 years, in accordance with the 2025 State of the Birds report.

5. If Chimney Swifts stay in your space, you need to be capable of discover them—simply search for. These aerial specialists spend practically all their waking hours on the wing, the place they could catch greater than 1,000 flies, beetles, and different bugs in a single day. They additionally drink water and bathe whereas in flight by swooping all the way down to a water physique’s floor. Because of swifts’ brisk, fluttering flight patterns, individuals usually confuse them with bats.

6. Occasionally Chimney Swifts even copulate on the wing, scientists imagine, although they extra sometimes mate on the nest website. During courtship, pairs carry out a show flight—a bonding habits that continues into autumn—during which they snap their wings upward to kind a V form. Another courtship habits entails small teams of swifts chasing each other, throughout which the species reaches a few of its highest flight speeds, which may exceed 60 miles per hour.

7. When they’re not in flight, Chimney Swifts are sometimes hanging out, fairly actually. Their tiny toes weren’t constructed for perching—swifts will not be recognized to land, stroll, or hop on horizontal surfaces—and as a substitute have 4 grappling-hook-like claws that assist them cling to vertical surfaces. Like woodpeckers, additionally they use their stiff tail feathers to prop them whereas upright.

8. Chimney Swifts have a particular instrument for constructing nests: their spit. When the birds arrive at their breeding grounds, sometimes in March or April, they kind pairs and discover a chimney or different appropriate website to lift their younger. They piece collectively a nest from twigs, holding it collectively and affixing it to the wall with their glue-like saliva, produced by glands beneath their tongues that get bigger throughout breeding season. Females lay 4 or 5 pure-white eggs, which, with luck, hatch about 20 days later.

9. During migration, vigilant birders can witness a tremendous spectacle. At nightfall, 1000’s of swifts kind an avian vortex as they swirl downward and dive headfirst right into a chimney to roost. Once inside, they rapidly flip to face upward and cling to a wall. The identical factor occurs on a smaller scale throughout nesting season, which could give the impression that the birds have fashioned a breeding colony. In truth, sometimes solely a single pair will nest in any given chimney, however they’re usually joined by dozens of unpaired swifts. When the mercury drops, swifts discover heat in numbers. Their physique warmth has been recognized to maintain a chimney as much as 70 levels Fahrenheit hotter than the temperature outdoors.

10. The shut connection between people and Chimney Swifts provides alternatives for individuals to become involved in defending the birds. Chimney buildings aren’t as widespread as they as soon as have been, and lots of present chimneys have been capped, blocking swifts from entry. But Audubon chapters and different teams across the birds’ vary are working to maintain chimneys obtainable for birds and to build towers that function good substitutes. (Find some helpful suggestions here.) Others host Swift Night Out occasions, inviting the general public to depend the birds as they swirl into chimneys and to find out about what they’ll do to guard these fascinating aerial acrobats.