Getting eaten alive by mosquitoes? If you have a chimney, there’s a little bird that can help.
Weighing in at a half-ounce to a full ounce, chimney swifts are bug-eating machines. Two adults and their offspring will consume “more than 12,000 flying insect pests every day, including mosquitoes, gnats, termites and biting flies,” according to Chimneyswift.org, which supports conservation of this native species. Barbara Dennis, who lives in Flint Hill, says she has had swifts nesting in her chimney since she and her husband, Bob, built their house in the 1970s and “never had a problem with mosquitoes.”
Chaetura pelagica is the only swift native to Virginia. While considered common globally, its numbers have been declining for decades. The hollow trees the swifts originally used for roosts started to disappear long before that as forests were cleared for farming and other development. The birds adapted by using man-made structures, especially brick or stone chimneys, which earned the species its common name. Then these chimneys started to disappear, were capped to keep wildlife out or were replaced with metal ones.
Chimney swifts don’t perch, but instead have evolved to cling to vertical surfaces, so their nesting options are limited. Rappahannock resident Amo Merritt, a permitted wildlife rehabilitator, showed me a young swift she’s been fostering since this spring. She pointed out the claws on its feet for hanging from the rough surfaces and the stiff bristles on its tail feathers that swifts wedge into cracks to secure purchase – roosting adaptations that are useless in a metal chimney.
Swifts can be noisy, especially when food is brought back to the young, a chore shared by all members of the family. However, they breed in May and by August the young have fledged and the noise subsides. Within a few weeks, the family leaves to join other related families, forming a large colony that roosts in larger shafts.
Amo says she plans to release the swift she has been fostering into a colony that roosts in a large chimney at the Sperryville Schoolhouse, adding that the colony will “literally take him under their wings” until he learns to soar with them. Both Amo and Rappahannock’s Virginia Cooperative Extension agent, Kenner Love, described the congregation of swifts in the evening there as “amazing.” Love noted that another colony at Rappahannock County High School appears to be three times as big.
In checking out the return of both colonies, I found the show put on at the high school was more impressive, with about 100 birds coming together. About 20 minutes before sunset, the birds started flying in toward the chimney, one at a time, chattering to each other. They came and went but gradually formed a loose, undulating flock, soaring back and forth over the chimney, diving down toward it occasionally. The flock grew and tightened up, becoming a huge, swirling mass of birds flying closer and closer to the chimney.
Then, right at sunset, one bird tucked in its wings slightly and dropped – not dived – into the chimney, followed by another and another, until all had entered. Kenner had aptly likened it being pulled in by a vacuum.
Bluish-black with a silvery throat, the chimney swift in flight looks like a cigar with curved wings attached, which has earned it the nickname of “flying cigar” or “bow and arrow.” With its wide mouth open to scoop up small flying insects, it blasts through the air at more than 200 mph – making it the fastest bird in the world, Amo says.
By late November, swift colonies take off for Peru for the winter. That’s a good time to clean out a chimney. The tiny swift nests are composed of twigs glued together and attached to the wall of the nesting site with saliva. According to the Texas Parks and Wildlife brochure “Environmental Tips for Professional Chimney Sweeps,” the nests pose no safety or health issues if chimneys are property cleaned each year. Cleaning also removes creosote that can build up and cause a safety hazard to humans and prevent the swifts from attaching their nests to the chimney’s walls.
One option for providing chimney swift habitat is putting up a nesting tower, which can be constructed out of materials available at most large hardware stores. It should be at least eight feet high and can be attached to buildings but should be in a clearing that’s at least 15 feet by 15 feet, according to “Providing & Maintaining Nesting Habitat for Chimney Swifts,” a brochure by Texas Parks and Wildlife (tpwd.state.tx). While large, wide towers can be built to offer roosts to whole colonies, each swift family needs a more intimate space to raise its young.
Wildlife rehabilitator Amo Merritt says she’s wanted towers near her place in Boston, in southern Rappahannock County, for some time, so she could place rescued baby swifts into the nests of swifts early enough to be adopted by the family. Recently, she got help from Boy Scout Rowan Hart, from Troop 1145 in Springfield, who had found her through the Wildlife Rescue League of Northern Virginia. Rowan was looking to complete an Eagle Scout service project and wanted to do something involving the outdoors and animals, according to an email he sent her.
With help from other troop members and parents, Rowan ended up building two 12-foot towers on a hill near Amo’s house, using the book “Chimney Swift Towers: New Habitat for America’s Mysterious Birds” as a guide. (The book, with detailed instructions and drawings, is available at Chimneyswifts.org.)
The Scouts built the interior of the towers, made of Textured One-eleven (T1-11) plywood siding, in sections. T1-11 has grooves that provide perches for the birds. Over the course of several weekends, the Scouts then erected the towers at Amo’s place. I watched one rainy Saturday as the boys slogged the sections up the muddy hill while a young blue jay Amo had just released carefully inspected everything and commented on their progress.
Once the towers were up, Rowan and his crew added insulation to the exterior, then aluminum siding outside that and finished off with metal flashing around the top few feet of the tower to keep predators out. When I went back to see the completed towers a week later, Amo pointed out some muddy paw prints going a few feet up one of them, indicating a bear had already checked it out.
Anyone interested in swifts is welcome to stop by to learn about them and the towers, says Amo. Contact her at firstname.lastname@example.org or 540-987-8431.