Quick Answers
Bluebirds are cavity nesters that often return to the same nesting site year after year. While there are some good reasons to remove old nests, such as preventing parasites or opening up the cavity for a new nest, retaining old nests can also benefit bluebirds. Leaving last year’s nest provides insulation and structure for new eggs and may encourage returning pairs to reuse the cavity. Consider monitoring the nest to ensure pests like house sparrows don’t take over before removing an old bluebird nest.
Bluebirds are beloved songbirds that add color and vitality to backyards across North America. These small thrushes readily take to nest boxes, delighting homeowners with their melodious warbles and flashy plumage. Bluebirds typically raise two broods per season. After the nestlings fledge, their cozy nest of pine needles and grass remains behind. This often leads caretakers to wonder—should you remove old bluebird nests or leave them in place?
This question has good arguments on both sides. Bluebird landlords may be tempted to clear out used nests for sanitary reasons or to provide a clean foundation for the next residents. However, bluebirds often prefer to reuse an old nest rather than build a completely new one. Leaving last year’s nursery intact can replenish nesting materials and give the new clutch added insulation.
To make the best decision for your bluebirds, consider why, when, and how to remove old nests from boxes or cavities. Understanding the pros and cons will help you balance bluebird conservation with responsible nest box management.
Reasons to Remove an Old Bluebird Nest
Here are some top reasons why removing an old bluebird nest may be beneficial:
– Prevents parasites – Old nests may harbor mites, fleas, and other external parasites that can infest and harm nestlings. Removing the old materials deprives these pests of a free ride into the new nest.
– Avoids overcrowding – Nest cavities can become increasingly shallow as remnants accumulate over successive years. Removing old nests prevents the cavity from becoming too cramped.
– Allows new nest construction – Not all bluebirds will reuse an old nest. Removing it gives the new pair a blank slate to build their own nest the way they want.
– Limits competition – Sometimes tree swallows, house sparrows, or other species will claim an old bluebird nest. Removing it opens up the box for the intended residents.
– Reduces mess – Old nests tend to get messier with rain, droppings, dead nestlings, etc. Removing them keeps the box cleaner.
– Provides suitable nesting habitat – If the old nest is sodden or deteriorating, taking it out allows the birds to start fresh with an intact, weather-resistant nursery.
Reasons to Leave the Old Nest
On the other hand, here are some benefits of leaving the old bluebird nest in place:
– Insulates eggs and nestlings – The old nest cup provides an extra buffer against cold and heat. The materials have already been compressed for a concave shape.
– Conserves energy – With the basic structure already built, the adults can focus their nesting efforts on shaping the interior rather than starting from scratch.
– Offers familiar site – Bluebirds exhibit strong site fidelity. Seeing an old nest may help guide them back to a cavity they occupied successfully before.
– Provides nesting materials – The old grasses and pine needles are readily incorporated into new nests. Birds may add a new cup right on top.
– Invites reuse – It’s common for bluebirds to reuse an old nest, especially early in the season. Leaving it in place increases the chance of it being recycled.
– Deters invaders – Used nests carry the scent of the former residents, which may deter competing species from claiming the box.
– Allows multi-broods – The first clutch can fledge and the nest be reused for a second brood in the same season.
When to Remove Old Nests
If you opt to remove old bluebird nests, timing is important. Here are some guidelines on when to clear out the old nursery:
– After both broods fledge – Let the bluebirds complete their full nesting cycle before removing a well-used nest.
– Before a new season begins – Winter is ideal as it avoids disrupting active nests. Remove nests after winter cleaning and maintenance.
– When switching nest sites – Relocating nests to alternate boxes helps give each one a fresh start.
– When infested – Heavily parasite-laden nests should be removed promptly to prevent reinfestation.
– If claiming other species – Once a competitor like House Sparrows takes over, quickly remove any old nests to reclaim the box.
– When deteriorated – Nest boxes may need an early nest change if the old nest becomes excessively weather-beaten or soiled.
– Before a new pair assumes the territory – First-time nesters may be more inclined to build their own nest than inherit another bird’s.
Signs It’s Time to Remove a Nest
How can you tell when an old bluebird nest has reached the end of its useful life? Here are some signs that it may be time for a change:
– Nest box floor visible – The nest cup is worn completely through in spots, exposing bare floor.
– Sagging, flattened cup – The interior nest bowl is compressed flat and no longer holds a concave shape.
– Very shallow interior – The nest has compressed to less than 1-2″ depth with little room for eggs and young.
– Hard, matted materials – The old grass is compacted into tough woody fibers rather than pliable blades.
– Sodden, rotting – Exposure to excessive moisture causes the nest to decompose and grow mold.
– Heavy parasite load – Close inspection reveals lots of viable mites, fleas, blowfly larvae, etc. still occupying the old nest.
– Takeover by other species – Sparrows, swallows, wrens or mice have moved in and claim the nest.
– Major structural damage – Large holes, tears, missing sections, or fallen exterior.
– Recent nestling death – A nestling died in the nest should be removed to reduce disease transmission.
Leaving the Nest Box Temporarily Empty
Another option is to remove the old nest but leave the box vacant for a short period. This allows you to clean and monitor the box while still giving bluebirds the chance to build fresh. Some tips:
– Clear nest after winter cleaning/maintenance – Nest removal and box cleaning often go hand-in-hand
– Time window – Leave the box empty for only 1-2 weeks to prevent other species from occupying the void
– Monitor frequently – Check the empty box daily to watch for returning bluebirds or competitors
– Close entrance briefly – A removable plate allows fast re-closure if needed to exclude other birds
– Have extra nesting materials – Offer pine straw or dry grass nearby to make quick nest building easier
– Be ready to accept old nest – Put back the familiar old nest if no new nest is started after several days
How to Remove an Old Bird’s Nest
When the time comes to clear out the old nursery, follow some basic steps to remove the nest as safely as possible:
– Cool nest – Avoids old parasites going airborne. Optional freezing overnight
– Sealable bag – Have a zip-lock plastic bag ready to contain debris
– Dump out – Tip the nest upside-down and shake out over the bag
– Check corners – Brush out any remaining nest bits with gloved hand
– Seal bag – Zip the bag closed tightly to secure contents
– Remove droppings – Use a dry brush, wood shims, or wet rag to clean waste
– Disinfect – Apply a natural cleaner to kill lingering bacteria inside the cavity
– Rinse out – Use plain water to thoroughly rinse away disinfectant residue
– Dry completely – Ensure no standing moisture remains before returning box outside
– Close box – Keep closed 1-2 days while monitoring for scavengers attracted to smells
– Reopen entrance – Unblock entrance once box is fully re-established to avoid early invaders
– Offer nesting material – Have a nearby basket of nesting material to help birds get a head start
What to Do With a Used Bluebird Nest
Once an old bluebird nest is removed from the box, there are a few options for proper disposal:
– Trash – Simply throwing the nest materials away in a sealed bag removes all risks.
– Burn – A controlled burn destroys any lingering parasites present in the old nest.
– Compost – For a nutrient boost, add to a hot active compost pile to break down fully.
– Crafts – Some enjoy repurposing beautiful old nests for wreaths, ornaments or displays. Use caution about pests.
– Education – Nest collections can have value for teaching students bird biology and monitoring studies.
– Leave for scavengers – Cleaned out gently, old nests left in woodlots provide resources for other wildlife.
Alternative Viewpoints
Views differ on whether removing bluebird nests is necessary or beneficial. Here are some other perspectives:
– Always remove – Some experts advise removing all old nests annually as vital box maintenance. They view this as ensuring the healthiest habitat.
– Case-by-case – Other guidelines recommend evaluating each nest individually and only removing those which show signs of parasites, damage, or crowding issues.
– Never remove – One school of thought is to always leave the old nests intact, as bluebirds preferentially use them. They believe this increases site fidelity.
– Mimic nature – Cavity nests in dead trees are rarely cleaned out in the wild between seasons. Leaving the old nests provides natural conditions bluebirds evolved with.
– Compromise – Some aim for a balance, removing very soiled or deteriorated nests but leaving alone those still in good shape for reuse.
There are good faith arguments on all sides of whether to remove old nests. Ultimately, it requires observing your own bluebirds’ behavior and preferences to determine what works best for your specific site.
Frequently Asked Questions
Here are answers to some common questions about removing old bluebird nests:
Do bluebirds reuse the same nest?
Yes, bluebirds often do reuse old nests, especially early in the breeding season. Renovating the old nest takes less effort than building a completely new one. The female may add a new lining or build a second cup on top of the old.
How often should you clean out nest boxes?
Most recommendations are to fully clean out nest boxes at least once per year. The best times are after fledging the last brood and before the next breeding season. Cleaning deters parasites and provides a fresh start.
Do you need to replace nesting material each year?
Replacing some or all nesting material annually helps give bluebirds a clean, pest-free start. Save any old material that’s in good shape for birds to incorporate into new nests on their own timeline.
Can leaving old nests attract predators?
In rare cases, accumulations of old nests and young scents in one spot may help attract predators like raccoons, rats or snakes. This is an exception rather than the rule, but is something to watch out for over time.
Will other birds use an old bluebird nest?
Sometimes. Species like tree swallows, chickadees, or house wrens may occupy an old bluebird nesting cavity. Monitor boxes and remove nests promptly if unwanted guests try to take over a prime bluebird site.
Key Considerations
To make informed decisions about removing old nests, keep these key points in mind:
– Do bluebirds in your area prefer to build fresh or reuse old nests? Observe trends at your site.
– Only remove nests between broods to avoid abandoning eggs or young.
– Note signs of parasites, deterioration, crowding, or other problems indicating a nest should go.
– Dispose of removed nests securely to prevent reinfestation from pests.
– Monitor emptied boxes closely for returning bluebirds versus competitors.
– Make sure neither nest removal nor old nest retention jeopardizes bluebird success.
– Adjust approaches over time based on your population’s health and productivity.
Conclusion
The question of whether to remove old bluebird nests requires balancing both risks and benefits. On one hand, keeping nests provides helpful structure, insulation and familiarity for the birds. On the other, removing them allows for parasite control, space, and fresh starts. Consider the specific needs and trends in your own bluebird population. Monitor boxes closely and adapt as needed to optimize bluebird success while also maintaining healthy nesting conditions. With observation and care, old nests can be cleared or retained in ways that best aid our cavity-nesting bluebird friends.
