Preparing your nest boxes for winter
As September arrives and the last bluebird fledglings have long since taken flight on their southbound migration, our focus turns to preparing nest boxes for the seasons ahead.
Fall maintenance is a vital part of bluebird conservation. By ensuring boxes are clean, safe and ready for use, we set the stage for another successful nesting season next year.
Mountain Bluebirds and other cavity-nesting species rely on well-maintained boxes. Old nests left inside can harbor parasites, mold, or mice, which may reduce the chances of successful nesting the following spring. By clearing out used material and repairing boxes before winter, volunteers protect the health of future generations.
Step 1: Clean out nest material
Remove any old nesting material, being mindful of potential hazards like deer mice. These animals are common and harmless to the birds but can carry Hantavirus. Always wear gloves, stand upwind, and if possible, use a mask. After emptying the box, spray the interior with a bleach-water solution (1 part bleach to 9 parts water) to disinfect. Leave the lid off for several hours to allow it to dry thoroughly.
You can read about past monitoring experiences from our volunteers.
Step 2: Inspect and repair boxes
Check the overall condition of each box. Look for:
Cracks or gaps that may let in water or cold air.
Loose screws or connections.
Evidence of chewing or wear around the entrance hole.
Simple repairs now will extend the lifespan of each box. If you encounter an old-style fixed-floor box, note it for replacement as MBTCS is working to phase these out in favor of improved designs.
Step 3: Check Predator Guards and Posts
Confirm that predator guards are secure and posts are sturdy. Replace any damaged guards and stabilize leaning posts before the ground freezes. Strong, straight posts reduce the risk of cattle damage or weather-related collapse.
For more details, visit our Essential Information for Trail Monitors page.
Share your work!
We’d love to see how our members care for their trails. As you clean out nest boxes this fall, please snap a photo of your work in action and share it with us. You can submit your photos and any personal tips or best practices to our online gallery at bluebirdtrails.org/photos.
Your stories and images not only inspire fellow monitors but also help show the broader community the dedication it takes to keep bluebirds thriving in southern Alberta.
A well-maintained trail ensures that when bluebirds return in early spring, they’ll find safe and welcoming homes. These small tasks, though often unseen, are the foundation of our success. Every volunteer who cleans a box, tightens a screw, or shares their experience is directly supporting bluebird survival.
As you head out this fall, take pride in knowing your work today is an investment in next year’s nesting season. Together, we are creating a legacy of healthy habitats for the future.
