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15 Eastern Bluebird Facts You Didn’t Know (2023)

Singing a melodious song and having rich blue, white, and rust plumage, the Eastern Bluebird is one of the most beautiful backyard birds. 

Having the willingness to occupy birdhouses and nesting boxes.

They are considered by many birders to be favorite visitors of theirs. 

Here are some Eastern Bluebird facts.

1. Bluebirds are cavity nesters and love nest boxes

Eastern bluebird (sialia sialis) nesting habits involve taking residence in tree cavities and they will use an artificial nest box. They like snug boxes with a 4-inch square base and a 1 ¾-inch diameter entry hole. Habitat and nest cavities have been disappearing for many years, but an incredible comeback has been made by bluebirds.


This is due to thousands of bluebird nest boxes being installed throughout the country. Eastern Bluebirds are easily found in open fields and sparse woodland areas, including along woodland edges and North America. Meadows, gardens, hedges, and parks are also good places to find bluebirds. You can find Eastern Bluebirds throughout North America.

2. Bluebirds are omnivores but love mealworms

Eastern bluebird can be easily drawn in with a small dish filled with mealworms. They prefer to eat live mealworms rather than dried. Bluebirds can spot caterpillars and insects in tall grass at a remarkable distance of over 50 yards. The Eastern Bluebird is an omnivore as it eats plants and meat.


Its diet consists of crickets, grasshoppers, and various beetles during the summer and berries, wild grapes, and honeysuckle during the fall and winter. The most common foods offered to backyard birds won’t be eaten by bluebirds, such as sunflower seeds, millet, and mixed birdseed. They also won’t sip hummingbird nectar.

3. The male Eastern Bluebird displays at his next cavity to attract a female

The male bluebird brings his nesting material to the hole of the tree, goes in and out, and waves his wings while perched above it. Like a courtship display, the male will sing and flutter in front of the female, partly spreading his wings and tail. 


The male makes minimal contributions to nest building as the female Eastern Bluebird builds the nest and incubates the eggs. Most bluebird nests can be seen in natural hollows in trees, in an old woodpecker hole, or in a birdhouse. Construction of the nest, which consists of weeds, twigs and dry grass, lasts around 10 days.

4. Eastern Bluebirds are very social

Flocks of 100 or more bluebirds will gather at times, though they are very territorial as well. They defend a territory around their nest during the breeding season, a feeding territory in the winter. Eastern Bluebirds are partially migratory. They are year-round residents in the southeastern United States, though they can go as far north as southern Canada in their summer breeding populations. 


When hunting, Eastern Bluebirds often fly from their perch to the ground to catch insects. Eastern Bluebirds are gregarious birds that live in flocks of 100 birds outside the breeding season. They communicate through songs and body language.

5. Eastern bluebirds may visit backyards if food is offered

Bluebirds (sialia sialis) don’t often come to feeders unless you have bluebird feeders that provide mealworms. Eastern Bluebirds are largely insectivorous in spring and summer. The bluebird range of eating consists of caterpillars, grubs, beetles, and other insects. The bluebird winter has a mixture of fruit and berries. 


Eastern Bluebirds do much foraging by perching low and fluttering down to the ground to catch insects, often hovering to pick up items instead of landing. They are also known to catch insects in mid-air and may take some while hovering among the foliage. On rare occasions, bluebirds will also eat small amphibians like frogs and lizards.

6. Male bluebirds sing beaks closed

Male bluebirds do not open their beaks widely when they sing, unlike some other songbirds like a Meadowlark. Males may stop singing during incubation periods. Male Eastern Bluebirds use different songs for mating and territoriality. A male may sing as many as 1,000 songs an hour when attempting to attract a mate. 


While the bluebird call is normally pleasant, certain chattering, bill snapping or clicking scolding calls are sometimes called a predator or anger song. Bluebird landlords may be able to tell one bluebird song of a male from another. Singing frequently in soft whispers, bluebirds provide pleasing musical series of mellow whistles.

7. The Eastern Bluebird’s song is one of its most distinguishing characteristics

The Eastern Bluebird song is a fairly low-pitched, warbling song that consists of several phrases, each containing 1 to 3 short notes. Harsher chattering notes may be interspersed with the whistles. Common eastern bluebird calls include sounds like the words “truly” or “purity” when repeated multiple times. 

The sounds will come out sounding like “chur lee” or “chir wi”. Eastern bluebird calls last less than a second, with males’ calls typically lasting longer than females’ calls. When they are approached by predators, males make a song-like warning cry. Females will begin to sing to bring a protective male back to the territory.

8. The North American Bluebird Society was formed to encourage bluebird nest boxes

In 1978 Dr. Lawrence Zeleny founded the North America Bluebird Society in order to promote the preservation of bluebirds by putting up nest boxes (1). Zeleny dedicated much of his life to providing nest boxes and managing bluebird trails. Through many talks and written articles, he promoted bluebird conservation. 


The Eastern Bluebird was declared a rare species because of its low population resulting from severe winters that occurred from 1976 to 1978. In 1996 it was taken off this list. According to the Ontario Breeding Bird Atlas, from 1968 to 2000, the population of Eastern Bluebirds showed a yearly increase of 6.5%.

9. The bluebird is the official bird of two states

Missouri and New York are the two states that are represented by the eastern bluebird as their official bird. On March 30, 1927, the bluebird was chosen to become Missouri’s official state bird. New York adopted the bluebird as their state bird in 1970. The bluebird won an informal referendum on April 13, 1928, held by the New York State Federation of Women’s Clubs. 

eastern bluebird

On January 31, 2020, SUNY Empire State College, based in Saratoga Springs, New York, chose the Eastern Bluebird to be the university’s official sports mascot. Blue the Bluebird symbolizes intelligence and curiosity, as well as optimism.

10. The oldest recorded Eastern Bluebird was at least 10 years, 6 months old

Eastern Bluebirds have a normal lifespan of 6 to 10 years. They can survive 6 years in the wild and up to 10 years in captivity. However, most mortality occurs in the first year of life, making average lifespans much shorter than this. 

bird bath

It is most likely that 70% of all bluebirds die before they last 1 year. The oldest known wild individual lived 10 years and 6 months (3). It had been banded in New York in May 1989 and was found dead in South Carolina in November 1999. Families of bluebirds flock together until the fall season when they marge with other family flocks.

11. The Eastern Bluebird lays two clutches per season

Female bluebirds lay 2 to 8 light blue or whitish eggs that hatch after 12 to 16 days. Eggs laid by the same female Eastern Bluebird have the same color, and so eggs in the same nest of different colors indicate those of a different female. 


Baby bluebirds are helpless at birth and will need parental guidance. Both parents provide food, mainly insects, for their chicks while they are in the nest. Chicks stay in the nest until the age of 15 to 20 days. While feeding chicks, both parents will carry away fecal sacs to keep the nesting area clean.

12. Bluebirds are very territorial

Eastern Bluebirds are also very territorial as they occupy and defend a territory of 1.1 hectares during the mating season. 120.8 hectares are defended during the winter. 

Do bluebirds migrate? When food becomes scarce during the winter, northern populations will migrate south. The preferred eastern bluebird habitat consists of open areas with scattered trees nearby for perching and roosting. 

bluebird singing

Where do bluebirds sleep at night? Sleeping places include pastures, orchards, parks, and meadows. Eastern Bluebirds will build nests in tree cavities to protect their young, in a behavior similar to that of woodpeckers. Bluebirds will sometimes construct their nests within abandoned woodpecker holes of trees.

13. There are three bluebird species and eight subspecies

There are 3 main species in the bluebird family, which are the Eastern Bluebird sialia sialis, the Mountain Bluebird (Siala currucoides), and the Western Bluebird (Siala mexicana). 

There are also 8 recognized subspecies of the Eastern Bluebird: the eastern bluebird sialia sialis, bermudensis, caribaea, episcopus (Tamaulipas Bluebird), fulva (Azure Bluebird), grata (Florida Bluebird), guatamalae (Southern Mexico), meridionalis (El Salvador, central and western Honduras, and north central Nicaragua), and nidificans (Veracruz, Mexico) (4). 

bird house

The alpha code for the Eastern Bluebird is EABL. There is a possibility that Eastern Bluebirds may interbreed with Mountain Bluebirds where their ranges overlap, most notably in North and South Dakota.

14. Bluebirds are the symbols of spring, happiness, love, and hope

Bluebirds are considered to be clear indicators of the spring season arriving. Since bluebirds can produce between 2 and 4 broods during the warmer months, they are associated with spring and renewal. They have been featured in many popular songs like “Somewhere Over the Rainbow,” “I’m Always Chasing Rainbows,” and “The White Cliffs of Dover.” 

bluebird feeder

In his book titled “The Bluebird: How You Can Help its Fight for Survival,” Dr. Zeleny makes a compelling testimony of why he calls bluebirds the symbol of love, hope, and happiness. A dead bluebird is a symbol of disillusionment, loss of innocence, and the transforming effects of age.

15. Bluebirds are generally monogamous

Being monogamous means that bluebirds form a basic social unit in the breeding territory. One study of Eastern Bluebirds (sialia sialis) in Georgia and South Carolina indicated that 95% of the time, nestings involve one male and one female (5). Mates stay together throughout the breeding season and may breed for more than one season. 

two bluebirds

However, some birds may switch mates during a breeding season in order to raise a second brood. Pairs are more likely to stick together if a previous nesting was successful. One study showed that 70-85% of successful pairs re-nested with the same partner in the same season, compared to 30-50% of unsuccessful pairs.

Read nextBluebird vs. Blue Jay: Songs, Habitat & Identification

21 thoughts on “15 Eastern Bluebird Facts You Didn’t Know (2023)”

  1. Avatar

    What amazing information about these beautiful birds. Last winter I managed to place several feeders all around my back yard. I have lived in my house for 25 years and as far as I recall, have not seen many blue birds. After the feeders, there were times I could count up to 8 blue birds gathered at 1 time. I have since gotten so very attached to them – and many other types of birds. I am so blessed to have a family of blue birds that nested in a house hanging right outside a window where my kitchen table is – it’s a bay window and I can see all activity. There has been a male and female caring for the eggs now for what seems weeks. I have seen the male go inside and stay as long as the female. I assumed he’s been doing his part sitting on the eggs. Well. now they’re both “working their feathers off” feeding these babies. One goes in and out, flies away – then the other does the same. Just this morning I could hear the babies chirping for their food every time one parent approached. I am so thrilled that I have this family of Bluebirds.With all this excitement, something happened this morning that has me VERY, VERY CONCERNED FOR THE ENTIRE FAMILY OF BLUE BIRDS. Another different male bluebird flew in and actually got inside the birdhouse and stayed a while. All while the daddy blue bird waited on a perch nearby. What’s this about? The eggs are hatched, so he couldn’t be inside the house for that, like eating the eggs. Is this normal for another bluebird to go inside a nest, while one of the parents is actually watching? He visited for a good little while – maybe 60-90 seconds – right inside the house. I really want to know if the babies are in any danger. I have not seen any other bird near the area but the 2 mates. So….what is this dude up to? Please someone advise so I can rest at ease that my little birds will be ok. Thank you so much. I also have to mention this, if you haven’t seen “Dancing with the Birds” on Netflix, you are missing out. This has to be the most enjoyable documentary about birds from various rain forests I have even watched. I have watched it 3 times now and have shared it with a few family members. It’s absolutely amazing what birds can do….Enjoy!

  2. Avatar
    B Kaye Stargel

    I have a nesting box in my backyard. The beginning of April I was excited to see 3 eggs in the box. I saw 2 different blue birds going in and out of the box. I know one of them sat on the eggs for extended periods of time. But its been almost 2 months and the eggs have never hatched. The last few days I’ve noticed the birds have quit coming to the box. How long should I wait before I clean out the box?

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    Do glad to find this sire. My husband and I have been watching blue birds couple from our kitchen windows. They’re such a good mate and parent … from building the nest into the bird house , feeding their chicks then went away for the weekend when we came back the chicks and mother bird were gone! We felt sad but then the male bird came back looking for them 😢. A week later both male and female bird are back rebuilt their nest again ❤️

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    I’ve got a nest box on a very tall house post with three bluebird eggs in it. I had scheduled siding and new posts to be put on my house and they have upped the date to do this. Will it hurt to move the box? Will the noise traumatize the fledglings if we leave it there until we absolutely have to move it? Any suggestions?

  5. Avatar

    I have 2 nest boxes. I watched as bluebirds build a nest in each box then laid 5 eggs in each box a few weeks apart. Shortly after all the eggs were laid in each nest the birds returned and covered the eggs with more nesting material then abandoned the eggs. I watched the eggs for 25 days. They never hatched. Any thought?

  6. Avatar

    I built a bird house for attracting blue birds. Today I noticed a male blue bird sticking his head in the hole, which is 1 1/2 inches in diameter. He is a decent sized bird. I thought the hole might be to small for him to eat into the box. Should I enlarge the hole? Does the mail actually go inside the box? Thank you!

  7. Avatar

    Last year, after the second brood fletched, I saw one deceased youngster at the bottom of the nest. Removal had to wait for the next day. When I returned about 24 hours later, the deceased youngster was GONE. Can anyone suggest what happened to it? I am mystified!

    1. Avatar

      It was probably eaten by a scavenger. Snakes, raccoons, and many other birds would love to make a meal out of a deceased chick.

      — Hailey Brophy
      Writer @ World Birds

  8. Avatar

    I live in Mississippi and have trouble each spring with male bluebirds constantly attacking their Reflections in the mirrors and windows of my cars. I’ve tried everything I can find to scare them away including reflective streamers and pie pans, small mirrors etc forming forming a curtain around my carport. Any thoughts?

    1. Avatar

      Because the male Bluebird sees himself as being another bird in HIS territory, this could go on for a long, long time. Trying to chase them away is futile because they see their reflection as another bird threatening his territory. There likely is a nest nearby with your having mentioned Spring and they are guarding their nest like good Daddies. You’d likely have better luck with moving your car during the breeding months or perhaps putting non-reflective shades on your windows. Good luck. It’s a bit humorous seeing them fighting themselves and can see how seriously they take protecting their nest and brood. Marcie

  9. Avatar
    Annette A.Preiss

    Vermont: On February 4, 2022 I had two bluebirds near the feeders. By February 9th there were seven. They are feeding on meal worms and peanut hearts. What a treasure to watch.

  10. Avatar

    Today is December 4th and a Bluebird just visited my bird feeder (mainly seed). I had Bluebird boxes set up for many years and for a while they nested in the boxes, then I found a dead mother and eggs in one of the boxes. I was told that most likely sparrows or wrens killed the mother while she sat on her eggs. The Bluebirds have not returned since. My question is do Bluebirds stay this far North (Upstate Central New York) for the Winter or is this unusual.

    1. Avatar

      I live in Ct. and have had many bluebirds winter over. I provide dried mealworms for them and they love it. I had two broods of bluebirds successfully fledge this past summer. I adore them. I have seen them at my bluebird feeder all winter long.

    2. Avatar

      Last year, during the height of the 17 year Cicada “storm” (icky, but harmless), I stood guard outside my birdhouse and chased the Sparrows away multiple times. I was HORRIFIED to learn that these English invaders will peck out the eyes and even kill mother Bluebirds hatching their eggs! I no longer think Sparrows “cute.”

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    Should old nests and boxes be cleaned out ? Once a year or after each nesting ? Or do they clean out , refresh nest themselves ??

    1. Avatar

      Yes clean out the boxes after each brood has left the nest using mild soap and water and rinse clean. Some suggest a mild bleach solution which I have not used.

    2. Avatar

      Our Northern Virginia Bluebird trail monitoring group cleans boxes in the fall of droppings, and replaces the old nest for roosting during the winter. Our Bluebirds generally stay in winter, and may use boxes to stay warm (many articles out there on how to help insulate boxes better). In February (to prep for spring breeding) we remove old nests, do a thorough clean-out scraping with putty knives and brushes, but use no chemicals or soaps. We’ve had many successful bluebird broods along our trails with this method.

    3. Avatar

      I always clean out my bluebird boxes after all the babies fledge. Last year I had 3 nestings in the same box. The last one though was abandoned. I’m not sure why but it was late in the summer. It may have been too late in the year or they were not fertile, but many babies were successful and have wintered over here. 😊

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