Chirrups in the Chimney
Smokestack stewards, it’s time to prepare for the springtime return of chimney swifts.
By Sheryl Smith-Rodgers
Wanted: more chimneys to house rapidly declining numbers of chimney swifts, those twittering, insect-devouring birds that flicker across our summer skies.
Since the late 1960s, populations of chimney swifts {Chaetura pelagica) have fallen by 44 percent, according to researchers with the 2004 North American Breeding Bird Survey. Findings by the Canadian Wildlife Service show numbers of birds there have plunged nearly 95 percent since 1968.
Metal chimneys and chimney caps have contributed to the birds’ sharp decline. Here’s why: Swifts don’t stand upright or perch horizontally like other birds. Physically they can’t. Instead, they cling to rough vertical surfaces with their grappling-hook feet and stiff, bristled tail feathers.
Historically, chimney swifts inhabited hollow trees. Deforestation led chimney swifts to adapt to using enclosed, man-made structures, namely chimneys constructed of stone, firebrick or masonry flue tiles with mortared joints. (Metal chimneys are too slick.)
Communally, swifts roost together at night in one enclosure. However, breeding pairs nest alone. That’s why more nesting habitat is needed to boost the swifts’ sagging numbers.
If your chimney fits the bill, you can help the species rebound by becoming a chimney swift landlord this spring. By the time you’re ready to light a fire next fall, they’ll be on their way to their Amazon wintering grounds in Peru.
Here’s how to prepare for chimney swift tenants:
- Ideally, chimneys should be cleaned by March 15. (Always cap metal chimneys; their slippery walls trap both swifts and other animals that may fall inside.) Annual removal of creosote residue inside the shaft prevents chimney fires and enhances walls for swift nest building.
- Breeding swifts gather nest material as they fly. Their glutinous saliva enables them to build and attach their half-cup nests on vertical surfaces. Accumulated soot on chimney walls may cause a nest to peel loose and fall, the common cause of mortality among baby chimney swifts.
- Chimney-cleaning kits are available at most home hardware supply stores. If you’d rather not do it yourself, hire a professional chimney sweep. However, always steer clear of companies that advertise “bird removal.” Destroying chimney swift nests violates state and federal regulations that protect migratory birds.
- Remove chimney caps over suitable chimneys in March and replace in October. Or replace the cap with a protective “roof” that’s open on all four sides. Supports should be a minimum of 12 inches high to allow swifts to enter the chimney.
- Keep dampers closed from March through October. This prevents birds from flying into the house and getting hurt. Also, a closed damper keeps nests from falling into the fireplace.
- If the birds’ raucous calls get too loud, wedge a large piece of foam rubber (don’t use fiberglass insulation) above the fireplace. Place a reminder note near the fireplace so you won’t forget to remove the foam before you light a fire.
Some of the noise will come from nestlings “yippering” loudly as they beg for food from returning parents. Once their calls become audible, that means they’re usually about 14 days or so away from fledging.
Paul and Georgean Kyle, who live in northwest Travis County, have studied chimney swifts since 1983. As devoted conservationists, they promote the construction of “artificial chimneys” to create more chimney swift habitat. Basic information on how to build chimney swift towers is included in their book, Chimney Swifts: America’s Mysterious Birds above the Fireplace (Texas A&M University Press, 2005).
“Chimney swifts are a species that can be helped on a one-by-one basis,” Paul Kyle says. “You as an individual and your chimney can make a difference in ensuring their survival.”
For more information, visit < www.chimneyswifts.org.>
