The Chimney Swift (Chaetura pelagica) is a summer visitor here, but unfortunately, they’re not always welcome. One of four species of swifts found in North America, they’re the most common species found east of the Rockies.
The Chimney Swift is a small, five-inch sooty colored gray-black bird, with a throat that’s a little lighter in color. Its beak is small, but its mouth is wide, large, and an effective insect trap. Swifts have scythe-shaped wings that span about 12” and cross over the tail feathers by an inch or so. The tail feathers are squared off, tipped with pointed bristles. These bristles and the grappling-hook-like toes with tiny claws enable swifts to cling to vertical surfaces from the time they’re only a day old. They have small, weak, feet and don’t perch or stand on their legs like other birds; they’re adapted to life aloft, not on the ground.
When early pioneers moved westward across the continent clearing forests, they also removed the swifts' natural habitat by felling hollow trees. Ultimately, this species adapted to man-made homesteads and masonry chimneys. Generally, swifts nest in May through August. Usually a pair raises one brood, but two may be attempted, especially if the first fails. The female lays 4-5 white eggs in a small twig nest that both adults construct from tips of tree branches that are actually glued together with the parents’ sticky saliva and attached to a vertical surface. There’s no nest lining so one parent must always incubate the eggs. Studies show the parents’ saliva plays an important role in proper development of youngsters. Since the food is also coated with this substance, it seems to positively affect their growth rates, development and well-being when nestlings are reared in the wild.
Hatchlings are pink, naked and dependent on parents for food and warmth. During the babies’ first week, they’re fed by regurgitation from the crop of both parents. Later, a pellet of insects is stored in the parents’ throat pouch until it’s fed to the offspring. At 15-17 days, babies’ eyes open, and bristly flight and body pinfeathers soon unfurl into feathers that initially feel like soft fur. Eventually, their plumage will be sleek and glossy as youngsters mature into adults.
When it’s dinnertime, nestlings chatter incessantly, eating many times their weight every day. During the time they make their noisy feeding calls, they’re incapable of sustained flight and are completely dependent on their parents for food, according to chimney swift experts from Austin, Georgean and Paul Kyle. The Kyles write, “Homeowners’ tolerance during this critical period is very important. If the young are forced from the chimney now, they’ll slowly starve to death over a period of several days. The parents are unable to care for them outside their chimney. Once the sound of the young becomes noticeable, they’re usually only ten days or so from fledging.” Keeping the damper closed and packing the fireplace with insulation can reduce the sound to tolerable levels during this brief period.
If a youngster accidentally falls down your chimney, simply place its Velcro-like feet as high on the chimney wall as you can reach, and it’ll climb back up to rejoin its parents. Plan your chimney cleaning before using the fireplace for the first time of the season. Nests themselves pose no fire hazards when they’re constructed in chimneys that are maintained. If you schedule a date for summer cleaning and a nest is discovered, reschedule at least six weeks later for a nest with eggs, and five weeks later for a nest with young. Today, some houses are built without chimneys, or chimneys with smaller metal flue pipes rather than a clay liner. Chimneys lined with metal should always be capped, since birds that enter them may become trapped.
Conservation of this unique, beneficial and fascinating species should not interfere with professional chimney sweeping. Companies that respect our wildlife laws will likely appeal to a wider range of individuals in our present climate of increased environmental awareness. Chimney sweep companies are urged to call the Wildlife Center at 806 799-2142, if they remove youngsters from an active nest so they can be raised and released.
Chimney Swifts are protected by Federal law under the Migratory Bird Treaty Act, and by Texas state law. People who deliberately and knowingly tamper with or remove swifts or their eggs are subject to penalties under the law. We know swifts are often ousted, but we urge homeowners to do the right thing for these very beneficial little birds. If you don’t want swifts having families in your chimney, a solution is incredibly simple: cap your chimney, and don’t wait until summer when it’s already occupied. All it takes is bending a small piece of hardware cloth or welded wire to create a tight ‘cap’ over the chimney’s top opening. Simply closing the damper or flue is not a solution to keeping swifts, raccoons or squirrels out.
The swift’s enemies are reptiles, mammals, and other birds. Texas rat snakes, Eastern screech owls and raccoons are responsible for many deaths, although not nearly so many that are burned, smoked, dislodged or otherwise excluded by people from suitable chimney and other stack sites each year. This is usually a result of intolerance or ignorance.
The swifts' round trip migration journey is about 6000 miles annually, and they winter in Peru in the Amazon Basin where insects are abundant year-round.