Being a Good Chimney Swift Landlord


An excerpt from the book


Chimney Swifts:  North America’s Mysterious Birds Above the Fireplace


by Georgean Z. Kyle and Paul D. Kyle

Texas A & M University Press

Copyright, 2005


 Providing nesting sites for Chimney Swifts is not as easy as putting up a prefabricated Purple Martin house or hanging out a nest box for Carolina Wrens, but it can be as simple as properly maintaining an existing fireplace chimney.  Since Chimney Swifts are in North America only during the warmest part of the year, there is seldom a conflict over time-sharing rights of a chimney.


For a chimney to be suitable for swifts, the inside must be made of stone, firebrick or masonry flue tiles with mortared joints.  These materials provide enough texture for the birds to be able to cling to the walls.  Metal chimneys are unsuitable and should always be capped. Any animal that enters a metal flue will fall to the bottom and be unable to climb the slippery walls.


Proper maintenance is crucial for any chimney whether it is to be used by Chimney Swifts or for winter fires. Wood fires produce flammable creosote residue that coats the inside of a chimney. If left unattended for more than a single season, this material will build up, and the entire layer may ignite with catastrophic results. A resulting chimney fire will spew burning cinders onto the roof and surrounding structures. The intense heat of such a fire may also cause permanent damage to a chimney.  In most cases, an annual cleaning will keep the chimney walls clean and safe for swifts and homeowners alike.  Most home hardware supply stores carry chimney-cleaning kits.  For those not inclined to do-it-yourself, there are many commercial chimney-cleaning companies that can be hired to handle the annual task.


Chimney Swifts build their nests by attaching small twigs to the chimney wall with their glue-like saliva. When completed, the shallow half-cup nest protrudes two to three inches from the wall. The most common cause of mortality in baby Chimney Swifts is fallen nests.  By keeping the chimney free of creosote build-up, homeowners help assure successful nest building, and decrease the chances of the nest falling before the birds have fledged.  Action should be taken before the swifts return from their wintering grounds in South America.  The best time to clean a chimney is in mid-March or when the local wood fire season is over.


More and more homeowners are electing to have their chimneys capped to prevent water damage and act as spark arrestors during the winter burning season.  In fact, some insurance companies require chimney caps be installed as a condition of their coverage.  However, it is a simple matter to arrange with your chimney cleaning professional to have the cap removed in the spring before the swifts arrive.  It can then be replaced in the fall in preparation for a safe wood fire season after the swifts have migrated south.  Another option is to install a cover that is open on the sides to shield the chimney from rain but still allow access to the swifts.  These covers can actually be attractive as well as functional.  As long as there is at least 12” between the top of the chimney and the cover, the swifts should have no trouble finding their way into the chimney.


The damper should be inspected during the annual chimney cleaning and should remain closed during the nesting season. This will prevent birds from flying into the house and becoming trapped or injured. A closed damper will also prevent a nest that does break loose from falling into the fireplace.  It also lessens the transfer of sound and will make the chimney quieter for the birds and homeowners alike. In older homes some fireplaces may not have dampers, or they may be inoperative.  In these cases, a large piece of foam rubber (do not use fiberglass insulation) can be wedged up from the fireplace to serve this purpose while the swifts are in residence.  If foam rubber is placed in the flue, it is a good idea to write a note and leave it in the fireplace so that the foam rubber is removed before the first fire of the season is lit in the fall.


Chimney Swifts are protected by Federal Law under the Migratory Bird Treaty Act. Unfortunately, some chimney cleaning companies will still illegally remove active nests with young and discard them to die slowly in trash receptacles.  When hiring a professional chimney cleaning company, be careful to select one that is reputable.   There are many companies that now actively promote Chimney Swift conservation.  Always keep in mind that “Bird Removal” is a blatant violation of the state and federal laws that protect Chimney Swifts and other migratory birds.  Homeowners should inquire about a company’s policy regarding Chimney Swifts.  Any company that offers or advertises such a service should be avoided. 


Authors’ note:  Chimney Swifts are protected by state and federal law, and a permit from both agencies is required to care for them.  Hand-rearing Chimney Swifts is extremely difficult, and has been known to bring even the most accomplished wildlife rehabilitators to their knees.

For a complete careguide on caring for Chimney Swifts see:


Rehabilitation and Conservation  of Chimney Swifts