Chimney Swifts, like many of our avian Neotropical migrants, are declining in numbers throughout North America. The purpose of the Chimney Swift Conservation Project is to promote Chimney Swift conservation by identifying and monitoring existing nest and roost sites, educating property owners about the beneficial nature of Chimney Swifts as insectivores and installing and monitoring new structures specifically for use by Chimney Swifts as nest and roost sites.
Why Chimney Swifts are in sharp decline
Between 1966 and 2019 Chimney Swift populations have dropped 67% in the United States according to the North American Breeding Bird Survey. Chimney Swifts are included in the Yellow Watch List for birds most at risk for extinction without significant conservation actions to reverse declines and reduce threats.
Research suggests there are many causes for the precipitous decline. The most obvious reasons are the lack of avian insects, their food source, and the lack of nest and roost sites. The use of insecticides on a global scale has affected bird populations worldwide.
Lack of nesting sites. Hundreds of years ago as deforestation spread across the country to make room for farms and cities swifts moved from nesting in old trees to nesting in the chimneys of the settler’s homes, churches, schools and abandoned wells. These human-made structures with deep dark shafts make ideal nest and roost sites.
Now with the removal of these antiquated man-made structures that the swifts came to rely upon, swift populations have plummeted. New homes are being built without chimneys and homeowners are capping their chimney as well as installing metal flues which the birds can’t cling to creating a death trap for any that enter. This has created a dire situation for the swifts who have depended on human-built structures for nesting and roosting for hundreds of years. They are now considered urban birds and need our help for their survival.
Chimney Swifts are one of 4 types of swifts that migrate to and from North America. Chimney Swifts spend the winter in the lower Amazon Basin until spring arrives in North America. They breed across the eastern half of the United States and Southern Canada.
These small birds, appropriately sooty grey and black with a silver-grey throat, are most commonly seen in flight. They soar high in the sky alternating between flickering bat-like movements then gliding gracefully searching for food on the wing. Their long scythe-shaped wings span about 12.5” and support a cigar shaped 5” body with a squared off tail tipped with pointed bristles. Usually seen in groups, the swifts make a chippering or ticking call as they fly overhead letting us know of their presence.
Chimney Swifts are unable to perch or stand upright as songbirds do to rest and nest. Instead, these fascinating little birds are uniquely equipped with strong forward-facing claws that act as grappling hooks so they can nest and rest on a rough vertical surface. The stiff spines at the tip of their tail provide additional support. Thus, masonry chimneys, air shafts, abandoned wells and old hollowed out trees make perfect nest and roost sites.
The nest is constructed of small twigs held together by saliva and attached to a vertical surface. Typically a nest will hold 3-5 white eggs. Both parents are involved in nest construction and take turns incubating the eggs for 18 to 19 days. The babies are fed by both parents until they fledge about 30 days after hatching. Once an entire brood has fledged, they will fly with their parents noisily around the nest site. The young will return to the nest site to roost as well as visit other roost sites in the area practicing flight maneuvers with neighboring young swifts.
Chimney Swifts do not tolerate another nesting pair in the chimney no matter how large it is. They sometimes will allow non-mating swifts to share the upper half of the chimney to roost and occasionally even employ a few helpers to feed the young. Since 60% of swifts do not mate in any given year, these birds roost along with the nesting pair. Rarely swifts will have a second brood.
Roost sites are of vital importance for the survival of Chimney Swifts in the spring, summer, and fall. Some swifts travel up to 5,000 miles one way to reach their destination. During fall migration, hundreds to many thousands of swifts congregate and roost in large chimneys to spend the night resting. Roosting together helps them to keep warm and conserve energy needed for the long journey. A network of roost sites along the way, old and new, shelter and protect the swifts from severe weather and allow the swifts time to refuel.
When the swifts return from their wintering grounds in the Amazon basin, often the birds will return to the same location they were born to nest and roost. These known networks of old chimneys have provided researchers with proof that conservation of these chimneys is crucial for the swift’s survival.
What we can do to help the survival of Chimney Swifts
Swifts do not require acres of unspoiled wilderness or complicated wildlife management plans. They only require one square foot of unused column like our chimneys during the summer when we don’t need them…and a little tolerance. (Kyle)
- Keep masonry or clay flue tile chimney tops open if it’s suitable for the birds to nest in.
- Close the damper from March through October to provide an opportunity for swifts to nest.Clean your chimney in the early spring before the swifts return from their winter grounds.
- Permanently cap metal chimneys to prevent wildlife from being trapped.
- Educate your friends and neighbors about Chimney Swifts.
- Stop using insecticides! Flying insects are food for the swifts (and all birds). A swift eats thousands of insects a day and when feeding their young up to 10,000 a day!
If you’re lucky enough to have swifts in your chimney don’t disturb them! Chimney Swifts are protected under the Bird Migratory Treaty Act of 1916. It is illegal to remove or disturb a nest! Simply wait until the birds leave in the fall to migrate south.
Building and monitoring your Chimney Swift Tower
Build a Chimney Swift Tower. There are many different tower designs in use and with a little creative planning chimney like structures can fit into a variety of locations. Plans are available online by googling Chimney Swift Towers or through the Chimney Swift Conservation Association at www.chimneyswift.org.
To see 2 new towers built with funds provided by Virginia Department of Wildlife Resources, Cape Henry Audubon Society, and other generous donors, visit Paradise Creek Nature Park, located on Victory Blvd. in Portsmouth, Virginia.
Once you build your tower monitor all activity spring, summer, and fall. Report your findings to ebird!
Swifts’ night out!
Attend Swifts Night Out events! Bring your family and friends to enjoy an evening watching hundreds to thousands of Chimney Swifts swirl through the sky chippering and performing ariel acrobatics before they descend into a known roost site during fall migration. This awe-inspiring event will leave you exhilarated and wanting to learn more about these fascinating little speed demons.
Raise the Roost for Chimney Swifts!
Make a donation to Cape Henry Audubon Society. Earmark your donation for the Chimney Swift Conservation Project. Ever year we contribute funds to assist other like-minded conservation groups interested in building towers.
Spread the word! For a printable pdf handout you can share with others, click on the link below.