Chimney swifts are small birds that nest in chimneys. While their chirping and fluttering may be charming, their nests can cause problems like chimney blockages and unsanitary droppings. Luckily, there are some natural ways to deter chimney swifts and prevent them from nesting in your chimney.
Why do chimney swifts nest in chimneys?
Chimney swifts get their name from their habit of nesting and roosting in chimneys. They prefer chimneys because they provide the ideal conditions for nesting:
- Dark and enclosed space
- Vertical surface to affix their nests
- Heat rising from the chimney
- Protection from predators
Chimneys are a substitute for the hollow trees and caves that chimney swifts nested in before human settlement provided them with abundant chimney habitats. A single chimney can become home to hundreds of nesting swifts during breeding season.
Problems caused by chimney swift nests
While seeing the birds enter and exit your chimney may seem charming at first, their nests can cause some unpleasant issues:
- Fire hazard: Nests can catch fire from the chimney’s heat, creating a dangerous situation.
- Chimney blockages: Nests fill up the flue space needed for proper ventilation, causing airflow issues.
- Pest droppings: Nests become littered with corrosive guano droppings.
- Bird parasites: Nesting materials can harbor mites, fleas, and other pests.
- Nesting noise: The flock makes constant fluttering and chirping sounds.
For these reasons, it’s best not to let chimney swifts continue nesting in your chimney year after year.
When do chimney swifts nest?
Chimney swifts migrate to northern climates like Canada and the U.S. to nest in early spring through late summer. Here are the general nesting times to be aware of:
- Early May – Arrive from migration and start constructing nests
- May to June – Egg laying and incubation
- June to July – Nestlings hatch and are fed in the nest
- July to August – Fledglings leave the nest but continue roosting
- September to October – Migrate south for the winter
It’s ideal to implement deterrents before the birds arrive in early spring, or after they leave for migration in the fall when the chimney is unoccupied.
Natural chimney swift deterrents
Here are some safe, humane, and natural ways to make your chimney less appealing to nesting chimney swifts:
Install chimney caps
Adding a customized chimney cap with narrow openings on top of your chimney will physically block chimney swifts from entering. Make sure the cap still allows for proper ventilation. Have them installed by a professional chimney sweep.
Use owl or hawk decoys
Hang fake plastic owls or hawks on the roof near the chimney opening. Chimney swifts will sense these predators and avoid the area.
Apply repellent odor
Spread natural repellents with strong scents around chimney openings. Options include:
- Mothballs
- Ammonia-soaked rags
- Predator urine
- Essential oils like peppermint, eucalyptus, tea tree
- Hot sauce
Reapply these repellents 2-3 times per week.
Use noise deterrents
Set up tactile deterrents like aluminum pie pans, wind chimes, or old CDs near the opening. The movement and reflective surfaces disturb the birds.
Seal cracks and crevices
Sealing any exterior cracks or crevices on your roof and chimney with caulk removes potential nesting spots swifts may use.
Allow fires in the fireplace
If you use your fireplace regularly, keep doing so even during nesting season. The smoke, heat and lack of quiet will discourage nesting inside the chimney.
Do chimney swifts return to the same nest?
Chimney swifts show high nest site fidelity, meaning they return to the same chimney year after year. A pair will reuse the same nest until they are no longer able to use it. Discouraging them from nesting one year can permanently stop them from returning in the future.
However, nesting sites in nearby chimneys are quickly adopted by other swifts. Using deterrents at neighboring properties as well can help prevent swifts from simply relocating next door.
Natural chimney swift repellents DIY
You can make your own natural chimney swift repellents at home using simple ingredients:
Mint oil repellent spray
- Add 15-20 drops of pure peppermint essential oil to a spray bottle filled with 2 cups water.
- Shake well and spray around the chimney opening.
- Reapply 2-3 times per week.
Eucalyptus repellent wreaths
- Gather 10-15 fresh eucalyptus branches and tie together into a wreath shape.
- Hang near the chimney opening so the scent wafts upwards.
- Make new wreaths every 2-3 weeks with fresh branches.
Vinegar mothball spray
- Fill a spray bottle with equal parts vinegar and water.
- Add 20 mothballs.
- Let sit overnight, then spray near the chimney.
When to get professional chimney swift removal
In some cases, it may be necessary to get professional chimney swift removal services. This is advised if:
- Your DIY deterrents were ineffective
- Large amounts of nests and droppings have accumulated
- You need nests and blockages physically removed
- There are year-round roosting swifts that never leave
- You have health concerns like allergies to guano
A trained chimney technician can safely dismantle nests, clear blockages, install exclusion devices, and offer other chimney repairs to prevent swifts from re-entering.
Are chimney swifts protected birds?
Chimney swifts are a migratory bird species native to North America. They are protected under the Migratory Bird Treaty Act. This federal act makes it illegal to:
- Kill, hunt, or trap chimney swifts
- Remove active nests with eggs or hatchlings
- Use pesticides on them
You can face potential fines and penalties for violating the MBTA protections. This means chimney swift deterrents and removals must be done humanely and legally.
Important tips for removing chimney swifts
Here are some key tips to ensure chimney swift control and removal is done properly and legally:
- Never disturb nests in use – wait until they are empty
- Work with professionals licensed to handle migratory birds
- Avoid harming or killing any birds
- Get any necessary permits from the U.S. Fish & Wildlife Service
- Use non-lethal exclusion methods recommended by experts
Conclusion
With some diligence, chimney swifts can be safely and humanely prevented from nesting in chimneys. Natural deterrents combined with chimney caps or repairs provide effective long-term solutions. Being mindful of the laws in place to protect chimney swifts will ensure both birds and homeowners can coexist peacefully.
