30 Amazing Bluebird Facts You
Probably Didn't Know (2021)

Is the bluebird territorial or social, or both? You will be fascinated to find out what these lovely birds are capable of doing!

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David A. Swanson

July 25, 2021

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What’s this post about?

The bluebird is a treat to the eyes and ears both. Many bird lovers enjoy their company because of their friendly behavioral characteristics, melodious voice, and beauty. There are so many things that observers and bird lovers should keep in mind

Bluebirds can be highly territorial and social, both depending upon the need of the situation. They prefer cavities to build homes and may end up using the same nest after one breeding season. You can build nest boxes for them and attract them with mealworms. 


Read below to find out some amazing facts about bluebirds. 

30 Amazing bluebird facts

There is so much more to these little bluebirds than the eye sees. Their energy, their behavior, and their lifestyle, in general, are incredibly fascinating. You can spend hours with birdwatching gear if there is a bluebird in your backyard.

You will be amazed once you explore the multiple facts about bluebirds. 

1. Bluebirds Are Not Blue


Unlike red and yellow feathers, the blue color in a bird is not generated from the pigments found in the food they consume. Instead, it employs a fascinating technique known as light scattering. Structural colors are created when light interacts with a three-dimensional object.

The 3D structure in this example is a bird’s feather. It functions similarly to how a prism does. Nature, on the other hand, employs a technique that is far more sophisticated.

The feather’s small air spaces and melanin pigment nanocrystals disperse blue light while absorbing other wavelengths. The feather’s much more delicate structure collects the reflecting blue wavelengths and sends them outward, which results in the various hues of blue that our eyes perceive.


A blue feather under UV light may seem completely gray.

2. Bluebirds Might Kill Each Other


Bluebirds killing each other is not a common occurrence and, in most cases, will be unintentional. However, there are recorded instances where bluebirds are seen attacking one another. The male will attack the male, the female will attack the female, and both parents may attack their young.

There are particular circumstances where bluebirds may end up killing their kind. Due to several reasons, sometimes not all eggs in a batch hatch together. When this happens, there is a high chance that the newly hatched chicks end up destroying the egg that is still intact.


A bluebird does not begin to incubate her eggs until the final egg is delivered. Delayed incubation is to ensure all chicks hatch together and they do not end up killing anyone.

3. Bluebirds Move Their Babies

Like most birds, bluebirds cannot relocate their nest, especially if it includes eggs or young. If they decide to relocate due to the presence of predators, they leave the nest and construct a new one in a different area. They may, however, remove the babies if they die inside the nest.

As mentioned previously, bluebirds often deliver eggs that do not hatch. If the bluebird notices the egg developing any infection, it will push the baby out of the nest. If the egg gets crushed by newly hatched fledging, the mother will remove the pieces of the egg from the nest.

4. Bluebirds are Protected Under Law

Bluebirds are protected federally under the Migratory Bird Treaty Act. Even if they are considered to be birds who disturb other birds while feeding or nesting, it is unlawful to transport, capture, or shoot native bluebirds without a license. 

It is also unlawful to remove or relocate active nests, even if they are in an inconvenient position. You will have to wait for the nesting season to be over and the birds to fly away.

5. Bluebirds Can Swim


You would be surprised to know that bluebirds can swim. There are recorded instances of bluebirds seen going underwater. However, there is no confirmation regarding how deep or how long they can go underwater. They love water in general, and installing bird baths to attract them is a widespread suggestion.

6. Bluebirds Can Somewhat See At Night

Diurnal birds like the bluebirds have more cones and fewer rods in their eyes, which means they aren’t entirely blind in the dark, but their night vision is restricted compared to nocturnal birds. Even yet, they can see in the dark considerably better than humans can.

7. Bluebirds Cannot Be Kept as Pets


Bluebirds are not suitable as pets. They might be lovely birds, but they do not adapt well to living in captivity. Keeping any of the three Bluebird species as a pet is prohibited. You may, however, construct nest boxes in your yard. They are easily attracted to locations that provide them habitat and nesting materials.

While this may not exactly be how you envision keeping a pet, it is the most accurate way. You do not have to cage the bird to consider it a pet. Having nest boxes will allow the bird to be free while also giving you easy access to them.

8. Bluebirds Are Fond of Humans

Bluebirds are incredibly adaptive. Some of the nests are found unexpectedly near to human activity. They have no reservations about breeding close to human settlements. They even tolerate humans peeking inside their nests to observe their fuzzy-headed hatchlings.

Now that natural cavities are scarce, bluebirds may not have an option but to like humans. They almost wholly depend upon humans to provide nesting boxes that aid their survival. Ironic since humans and urbanization are the reasons bluebirds have to rely on them in the first place.

9. Bluebirds Kill Their Babies

The bluebird will kill their babies as an act of protection and not aggression. If the egg gets infected or is infertile, it becomes necessary for the parents to get rid of the baby. They do not want newly hatched fledging to stomp on the egg or get infected by the bacteria contaminating the rotten egg.

Some situations force the parents into attacking their children. These otherwise gentle birds can become aggressive towards their juveniles during the nesting season. 

10.  Bluebirds Are Territorial

Bluebirds may appear peaceful, yet they are fiercely protective of their partners, territories, and children. As previously mentioned, bluebirds may end up attacking their kind in some circumstances. However, males fight males and females fight females.

Bluebirds can be considered highly territorial as they work hard to keep all other birds away from their site. During the incubation period, the male’s primary job is to feed the female and protect the family from intruders.


Bluebirds inhabit and protect a 1.1-hectare area during the breeding season? And during wintertime, 120.8 hectares are guarded.

Bluebirds may get aggressive as well under specific situations like:

  1. If their females’ gaze is straying, the male will notice it and defend their partners more tightly if they’ve been fooling around. These conflicts can be so fierce that they can either leave the bird dead or disabled.
  2.  The females can become aggressive during the nesting period because many birds dump their eggs into bluebird nests.
  3. When juveniles compete for food that is meant for the nestlings, bluebirds get aggressive.


Extra-pair copulations account for around 20% of their offspring despite bluebirds being considered monogamous.

11.  Bluebirds Nest in Cavities

Although the bluebird is a cavity-nesting bird, it is unable to construct its cavity. It must depend on deserted woodpecker openings or seek other natural spaces such as the exposed tops of rotting stumps or wooden fence posts. Since these places are not abundant, nesting boxes are also accepted.

Nesting couples usually choose holes 3 to 20 feet above ground in places with vast fields and multiple perches that allow easy access to insects. The nesting space plays a crucial role in fledgling development since young bluebirds stay in the nest for 15 to 18 days after hatching, reliant on their parents.

12.  Bluebirds Abandon Their Nests

Both genders of Bluebirds have separate roles during the breeding season, and losing one pair at specified intervals might result in nest abandonment. Other factors include the inability of the egg to hatch, the eggs exposed to excessive heat, or the nest or eggs being attacked by a predator.

In all of the situations mentioned above, whether the egg becomes unviable, or the single parent fails to nurture them alone, the parents abandon their nest and start the breeding process all over again. Sometimes, the bluebird may even build a nest on top of the old eggs that are no longer fertile.

13.  Bluebirds Reuse Their Nests

Species that make nests in enclosed places, tree holes or birdhouses, are more likely to raise a second clutch in those locations contingent on the nest being in excellent condition and the site remaining desirable.

Because bluebirds may reuse their nests, it is recommended to clean out the nesting box after one breeding season. The bluebirds don’t realize that adding more material to their existing nest will bring it closer to the entrance. This exposes the chicks to predators and a warm climate.


To avoid attracting predators, dispose of the old materials from the birdhouse.

14.  Bluebird Nests Are Made of Woven Grass

Woven grass, pine needles, hay, animal fur, and even feathers are some of the materials used by bluebirds. It is a clean, cup-shaped nest. Seed heads, cigarette butts, threads, sticks, and other rubbish are rarely seen in Bluebird nests. The depression created within the nesting material is found at the rear end of the box to keep it far from the entrance.

15.  Bluebirds Use Nest Boxes As A Habitat

All bluebirds are cavity nesters, and an artificial nest box can be used. The natural environment and nest cavities they need have been vanishing for years. Thanks to hundreds of nest boxes constructed around the land, they have made a remarkable comeback.

Because of rapid urbanization and landscaping, nest boxes have become the only habitat bluebirds have in most areas. They no longer can reuse cavities made by woodpeckers or use decaying trees that provide natural holes.

16.  North American Bluebird Society 

After severe winters in 1976 and 1978, the bluebird was declared rare. The North American Bluebird Society is a non-profit education, preservation, and research institute dedicated to restoring bluebirds and other North American cavity-nesting species.

It was formed in 1978 by Dr. Lawrence Zeleny to support the conservation of bluebirds by installing nest boxes.  Zeleny spent a large part of his life putting up nest boxes and maintaining bluebird routes.

17. Bluebird Nest Box Preferences

The construction of bluebird nest boxes is relatively cheap and straightforward. There are, however, certain specific conditions that you must meet. Bluebirds prefer open-air nest boxes; even a tiny yard with plenty of open areas would suffice. They also like to reside near an abundant source of insect food.

All Eastern bluebird houses should have a 1 1/2” diameter entry hole. This opening is big enough to permit eastern bluebirds in but not large enough to allow larger birds like sparrows through. Do not place a perch outside for the same reason. Bluebirds’ feet are designed to grip wood, so they do not need it, but it may attract other birds that do.

Some other essential suggestions are:

  • Construct the nesting box out of wood
  • The wood should be at least 3/4” thick; this helps minimize deformation and improves the box’s insulating properties during those cold spring evenings.
  • Include drainage holes at the bottom of the box.
  • Incorporate some cross-ventilation in addition to the entry hole allowing in air

18. Bluebirds Are Monogamous


Bluebirds are generally monogamous as they establish a fundamental social group in the mating region. 95% of the time, bluebirds mate for life if both partners stay alive. The mates remain together for the whole mating season and may breed many times.

Mated couples have been seen to participate in extra-pair copulations in the past. According to genetic research, 20-30% of broods studied were sired by more than one male Bluebird; this mainly occurs if an early nesting effort fails and the pair cannot raise a successful family together.

19.  Bluebirds Are Omnivore


The Eastern Bluebird consumes both vegetables and meat, making it an omnivore. It eats crickets, grasshoppers, and different beetles during the summertime, while in the fall and winter, it eats berries, wild grapes, and honeysuckle.


Do not put out sunflower seeds, millet, and mixed birdseed, which are commonly fed to backyard birds as bluebirds do not consume them.

20.  Bluebirds Have Excellent Vision

The ability to identify insects is one of the reasons bluebirds prefer open places with tiny grass. The bluebirds generally eat grasshoppers or other small insects by swooping down from a tree and grabbing them. Their vision is so excellent that they can find food from a distance of around 100 feet.

Mountain bluebirds can hover above the ground while looking for insects, unlike other species that descend from a perch while hunting. Their exceptional vision and flying abilities allow them to live in regions with no trees or bushes.

21.  Feed Worms to Attract Bluebirds


According to a study, insects make up 68 percent of the diet of bluebirds. So, a tiny dish packed with mealworms might readily attract an Eastern Bluebird. They favor live mealworms over dried mealworms. Don’t worry about the birds being able to spot it from a distance because bluebirds have exceptional eyesight.

Other ways you can attract a bluebird are:

  • Construct a perch as Bluebirds explore the landscape and search for insects from elevated standpoints.
  • Play a pre-recorded Bluebird Son
  • Put out feeders that meet Bluebirds requirements
  • Install nesting boxes and provide nesting material
  • Put away domestic animals
  • Install a birdbath


Avoid overdoing it, especially during the breeding season. It has the potential to divert them from caring for their young, protecting their nest, and obtaining food.

22.  Male bluebirds Sing and Dance to Attract Female Bluebirds


The male bluebird carries its nesting materials to the selected nesting region. He then enters and exits and flaps his wings while poised above it. The male will sing and dance in front of the female, partly extending his wings and tail, similar to a courting performance.

23.  Male Bluebirds Do Not Help Build the Nest

The majority of bluebird nests may be found in natural tree holes, an old woodpecker cavity, or a birdhouse. It takes around ten days to build a nest that is primarily made of twigs, sticks, and grass. But this is done by the female alone. The male Eastern Bluebird contributes very little to nest construction.

After luring the female to the nesting location, the male’s job comes to a halt. He gathers nesting materials to attract the female but does not participate in the actual building. The male’s next job is to feed and guard the female during incubation.

24. Bluebirds Are Social

Bluebirds are known for being territorial. During the mating season, they protect an area surrounding their nest, and during the winter, they guard a feeding region. Outside of the breeding season, though, they may be rather friendly.

Eastern Bluebirds are social birds who dwell in groups of up to 100 birds. They interact with one another through songs and mannerisms.

25.  Bluebirds Sing Songs

Bluebirds have a low-pitched, shrieking song divided into numerous phrases, each with 1-3 short notes. Whistles may be mixed with louder chattering sounds. The tune lasts around 2 seconds in total. Unlike several other songbirds, male bluebirds do not expand their beaks open when singing.

You may hear this song multiple times, and they may each be for a different reason. For example:

  • Single males sing this song from an elevated perch or in flight, usually in an attempt to attract a partner.
  • When females perceive predators in their area, they may sing this song.
  • While females are producing eggs, partnered males may sing a quieter rendition of the song.


Male Bluebirds can sing up to 1000 songs when attracting a female.

26.  Bluebird is the Official Bird of New York

The Eastern Bluebird is considered the official bird of Missouri and New York, both. In 1970, the bluebird was designated as New York’s official state bird, 20 years after its population was considered low.

The bluebird species has recovered in recent years and may now be found in various eastern environments, from woods to farms.

The bluebird was designated as Missouri’s official state bird on March 30, 1927. They were selected in Missouri because they are regarded as a “symbol of happiness”. It’s appropriate because their song also sounds like “cheer-cheery up”.

27.  Bluebirds Rarely Live for More than Ten Years

Bluebirds have a six to ten-year lifespan. Bluebirds are expected to live for up to ten years and five months at a maximum. The majority of bluebirds, however, die during their first year of birth due to harsh climate, illness, or predation.


70% of all Bluebirds would most likely die before they reach the age of one year.

28.  Bluebirds May Lay Pink or White Eggs


The eggs of bluebirds are generally blue. They can be a variety of colors, including pale blue, powder blue, and blueish white. In rare circumstances, though, some females may lay white or pink eggs. The egg color does not vary within a batch.

A female can lay completely blue, entirely white, or completely pink eggs. If you find different colored eggs in one nest, it shows that another female laid her eggs in it. In situations like these, the nest owner will abandon all eggs and build another nest on top of them to start another breeding process.

29.  There are Three Types of Bluebirds

Bluebirds are one of the few species of thrush found in North America. There are three types of bluebirds. The Eastern bluebird is located in the east, while the Western and Mountain bluebird are found in the west. In a tiny section of the Southwest, both eastern and westerns may be seen.

The plumage of Mountain bluebirds is blue, while the Eastern and Western Bluebirds are blue and rosy beige. Female birds are less colorful than males, but their vibrant colors are comparable, and there is no visible size distinction between the two genders.

30.  Cats and Snakes Prey on Bluebirds

Bluebirds are preyed upon by various predators, including cats, snakes, raccoons, squirrels, and more giant birds. Cats are dangerous at all times of life, but they are especially dangerous during nesting cycles when they can murder adults in the box and destroy entire broods of chicks.

House sparrows raid bluebird nests (and other species) and may often murder both parents and chicks. They will even construct their nest on top of the birds they have killed.


The installation of predator guards and careful positioning of nest boxes can substantially decrease the risk of predators.

Keep Reading!

Many bird enthusiasts like the company of Bluebirds because of their pleasant demeanor, beautiful song, and attractiveness. Their vitality, their attitude, and their way of life, in general, are all fascinating. If you have a bluebird on your property, you may spend hours with birding equipment.

Some of the information you will learn will astound you. It is fascinating how both genders play specific roles in the breeding process, how they nest in cavities, or how they have incredible vision. Now that you have learned about bluebirds, read some astounding cardinal facts .

42 Amazing Cardinal Facts You Probably Didn't Know!

Have you spotted another enchanting Cardinal in your backyard today? Read this post to explore astounding facts about Cardinals. You'll be surprised!

David A. Swanson Picture

By David A. Swanson

Bird Watching USA

My name is David and I'm the the founder of Bird Watching USA! I started Bird Watching with My father-in-law many years ago, and I've become an addict to watching these beautiful creatures. I've learnt so much over about bird watching over the years that I want to share with the world everything I know about them!

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David A. Swanson Picture

David A. Swanson

Bird Watching USA

My name is David and I'm the the founder of Bird Watching USA! I started Bird Watching with My father-in-law many years ago, and I've become an addict to watching these beautiful creatures. I've learnt so much over about bird watching over the years that I want to share with the world everything I know about them!



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