Bluebirds are beautiful songbirds that bring joy to backyards across North America. If you’ve wondered where these little birds go when the sun sets, you’re not alone! Many bluebird enthusiasts want to know the details of bluebird sleeping habits.
If you’re short on time, here’s the quick answer: Bluebirds roost in cavities of trees, nest boxes, or dense shrubs and vines at night to sleep and stay warm.
Bluebirds Roost in Cavities and Dense Vegetation at Night
Cavities Offer Protection and Warmth
At night, bluebirds seek out cavities in trees, nest boxes, or other structures to roost in for the night. Cavities offer bluebirds warmth and protection from the elements and predators. Bluebirds will often return to the same cavity night after night.
According to the Bluebird Society of Pennsylvania, cavities allow bluebirds to conserve energy as they lower their body temperature and heart rate at night.
Cavities with small entrances are ideal for bluebirds to roost in. The small opening helps retain heat inside the cavity while also preventing larger animals from entering. Cavities in dead trees or holes created by woodpeckers are common natural cavity sites used by roosting bluebirds at night.
Nest boxes specifically designed for bluebirds can also provide excellent roosting spots. Proper nest box placement, mounting, and maintenance are important to make the nest boxes suitable overnight refuge.
Shrubs and Vines Also Provide Shelter
In addition to cavities, bluebirds may also roost in dense shrubs, brush piles, or vine tangles overnight. Sites that offer thickness and cover give bluebirds a place to escape wind, rain, and prowling nocturnal predators.
Common roosting shrubs used by bluebirds include multiflora rose, honeysuckle, bittersweet, and entanglements of vines like Virginia creeper.
Researchers in one study found that male bluebirds preferred roosting in cavities while females were more likely to use vine tangles. The differences may relate to thermoregulation needs between males and females.
The tangled vegetation provides insulation and shelter from the elements and protection from owls and other predators during the bluebirds’ most vulnerable nighttime hours.
Bluebird Roosting Behavior and Habits
They Return to the Same Roosts
Bluebirds exhibit a strong loyalty to their nighttime communal roosting spots, often returning to the same location every evening. Studies of banded Eastern Bluebirds found that some return to a favorite cavity or nest box year after year as long as it remains suitable.
The familiarity and safety of these tried-and-true roosts is likely welcoming after a long day of foraging.
Bluebirds Huddle Together for Warmth
When settling down to rest, bluebirds will gather closely together with their fellows for warmth. This huddling behavior serves an important thermoregulatory function. As the ambient temperature drops with the setting sun,
As highly social creatures, the companionship may also simply feel comforting and secure to bluebirds as they bed down for the night.
Roosting Starts Shortly Before Sunset
Bluebirds will begin congregating at favored roosting cavities approximately 30-60 minutes before dusk. This offers plenty of time for stragglers to join the slumber party before it gets too dim to find the way.
For their health and safety, it is advantageous for the birds to settle in early. The low lighting makes predators harder to spot, so getting to shelter promptly reduces risks. Roosting together also aids in defending against potential attacks and deters intrusion in the first place.
Overall, this sunset swarming behavior provides key protection as the bluebirds rest up for another busy day on the wing.
1 Brush, Tim. “Timing and Functions of Cavity Roosts of Eastern Bluebirds in Winter.” The Wilson Bulletin, 16 Sept. 1983, https://www-jstor-org.abc.edu
Ideal Roosting Sites for Bluebirds
Bluebirds require specific environments to comfortably roost for the night. Ideally, they prefer protected spots that provide shelter from the elements and predators. Their favored sleeping spaces include:
Tree Cavities
Bluebirds often nest inside the natural hollows of old trees during breeding season. They will also use these tree cavities as night roosts after nesting is complete. The cavities provide insulation and a safe refuge from predators and severe weather.
Nest Boxes Provide Man-Made Cavities
Many people put up specialized nest boxes to attract breeding bluebirds in spring. These nest boxes essentially create man-made tree cavities. Bluebirds will happily continue to use nest boxes as night roosts in fall and winter after young birds have fledged.
Dense Bushes and Vines
In the absence of quality cavities, bluebirds frequently roost in dense thickets and tangles of vegetation. Favored bushes include honeysuckle, rose, blackberries, and ornamentals like pyracantha. Vining plants like Virginia creeper and bittersweet also provide concealed, protected places for bluebirds to spend the night.
While bluebirds aren’t too picky about night roosts outside breeding season, they clearly prefer enclosed spaces that provide warmth, seclusion, and refuge. Whether natural or man-made, cavities fit the bill during cooler months.
But don’t underestimate the value of a thick, thorny rose bush when better shelter is unavailable!
To learn more about bluebird behavior, visit the Audubon Society and NestWatch websites.
Roosting Through the Year and in Bad Weather
Bluebirds Use Cavities Year-Round
Bluebirds rely on cavities for roosting throughout the year, not just for nesting in spring and summer. They seek out hollows in trees, old woodpecker holes, and nest boxes as safe spots to sleep at night.
Cavity roosting helps bluebirds retain body heat and find shelter from predators and inclement weather.
In winter, bluebirds will roost in cavities communally, huddling together for warmth. According to the North American Bluebird Society, as many as 50-100 bluebirds may pack into a single cavity on extremely cold nights! This behavior is crucial to their survival in harsh weather.
They Find Shelter in Storms and Cold Weather
When brutal winter conditions strike, bluebirds need to take cover to survive. Frigid temperatures can quickly lead to hypothermia and freeze their food sources. Ice storms can coat branches with heavy glaze that makes finding insects difficult.
And blizzards bring life-threatening winds and whiteout conditions.
Bluebirds don’t migrate far and remain in their breeding grounds all year. So they must adapt to drastic seasonal shifts. Finding a secure roost is top priority when the weather takes a turn for the worse. Old woodpecker cavities, nest boxes, and even animal burrows provide refuge.
According to the Bluebird Society of Pennsylvania, bluebirds start scouting their roosting spots early in the day to beat competing species like chickadees to the prime real estate. When an extreme winter storm hits, they fluff up their feathers for insulation and hunker down in their cavity to wait it out.
Providing properly constructed nest boxes specifically for bluebirds can help their populations thrive in areas with limited natural cavities. And planting winter berry bushes gives them a reliable food source nearby when icy conditions make foraging difficult.
With our support, these beautiful songbirds can weather almost anything!
Making Your Yard Bluebird-Friendly for Roosting
Put Up a Nest Box
Installing a nest box specifically designed for bluebirds is one of the best ways to attract these beautiful songbirds to roost in your yard (Audubon). Bluebirds prefer nest boxes made of untreated wood that have a 1.5 inch diameter entrance hole located 5-6 feet above ground.
Position the box with the entrance hole facing an open area and away from prevailing winds. Also, make sure to clean out old nests in the fall so your box is ready for springtime tenants.
Plant Native Bushes and Trees
Bluebirds roost in cavities in bushes and trees at night and during bad weather. Some good options for bluebird-friendly plants include native species like dogwood, elderberry, serviceberry, sumac, and viburnum (NestWatch). These plants provide great cover as well as berries that bluebirds relish.
Plant them in clusters around your yard to encourage bluebirds to settle in for the night.
Make Water Available
Putting out a birdbath or fountain provides bluebirds with the fresh water they need for drinking and bathing. Make sure to place it in an open area of your yard and keep it clean and filled. You can also add a mister to give them a fun shower!
Providing water can entice bluebirds to make your yard part of their daily habitat (The Old Farmer’s Almanac). 😊
Conclusion
As you can see, bluebirds utilize cavities, nest boxes, bushes, and other dense vegetation to safely and warmly roost at night and through all seasons.
By making your yard attractive to them with roosting sites, food sources, and water, you can invite these beautiful songbirds to stay in your area. With proper habitat, you may get to enjoy seeing bluebirds settle in to rest right outside your window when dusk falls!
