Discovering The Eastern Bluebird - A Complete Guide

One of the first ways people try to attract Bluebirds is to place birdhouses on their property. Doing so correctly, and monitoring them is a great start.

But if you provide the right types of food and cover for them to raise their young, you'll make your backyard more inviting and have a greater chance of watching these birds nest in your yard.

Although they were once declining in population, they have made a remarkable comeback.

Many may not know that the Eastern Bluebird was once as common as the American Robin is today.

Description: Size, Field Marks

Eastern Bluebirds measure 6 1/2 inches from beak to tail tip. The male has bright blue upperparts, reddish breasts, and a white belly.

The female has a buffy throat and breast, a grayish-blue head and back with light blue wings, and a tail.

Male Eastern Bluebird Perching in Tree

Bluebirds can be found in rural gardens, orchards, and suburban gardens near open farmland.

Nesting Habits: Breeding Season

The breeding season for Eastern Bluebirds begins in April and will go through July, although a couple of weeks on either side is possible.

These birds are cavity nesters making them ideal candidates for a birdhouse.

Entrance Hole Protector

Nest Materials Used

The nest is made of grasses, plant stems, and pine needles. The inside is lined with hair, feathers, and fine grasses. They prefer old abandoned woodpecker hols or birdhouses that are 4-20 feet above the ground.

Egg Laying, Incubation, Broods

The female lays 1 egg each day until the clutch size reaches between 3-6 pale blue eggs.

The female will begin incubating the eggs when the last or next to the last egg is laid.

Before the completion of egg laying, the female will go out and feed each day. She has not abandoned the nest and eggs.

Incubation (birds do not have a gestation period) will last between 13 and 16 days and the young will leave the nest within 15 to 20 days of hatching.

Eastern Bluebird Call

Their song is a melodious and cheerful warble that often starts with a few short, low-pitched notes, followed by a series of musical whistles.

The song is often described as sweet and mellow, with a distinctive, flute-like quality that carries through the air.

Do the Adults Sleep With Their Babies?

When baby bluebirds hatch, they are featherless and unable to regulate their body temperature. The female broods them by covering them with her body.

She will leave from time to time to find insects to feed the young, but stay and brood for a while after each feeding.

The male will keep bringing food to the young continually, without brooding.

Both the male and female birds will take turns sleeping in the nest box to guard the eggs or chicks.

They will often fluff up their feathers and tuck their heads under their wings to conserve body heat and rest during the night.

After the young leave the nest, the male continues to teach them how to find food and protect themselves from predators.

The male will often keep feeding the fledglings while the female begins a second nest. Depending on weather and other factors, up to 4 broods may be raised.

These fledgling birds may stay together through fall and join other flocks later. The young will claim new territories and not nest where they were born.

When do the Babies Leave the Nest?

As stated above, the young will leave the nest in 15 to 20 days after hatching. The adults will begin withholding food.

The adults will have food in their beaks and be in sight of the nest site so the young bluebirds can see them.

While calling to the young and because the babies are hungry, the birds will fledge from the nest to get fed.

So if you don't see the adults around as often, this may be the reason. They are trying to get the young out on their own.

Where do Fledglings Sleep at Night?

Fledgling bluebirds are young birds that have recently left their nest and are learning to fly and feed themselves.

At night, they typically roost together in trees or shrubs close to their nest site.

They may also roost in birdhouses or other artificial nesting sites that are suitable for bluebirds.

It is important to note that fledgling bluebirds may be vulnerable to predation and other dangers, such as cold temperatures, during their first few nights out of the nest.

Therefore, it is important to provide suitable nesting sites and other support to help ensure their survival.

Additionally, it is important to avoid disturbing them during this critical time, as human interference can be harmful to their well-being.

Bird Houses

If you plan on putting up a birdhouse, for Eastern Bluebirds, place it on a pole 5 to 6 feet above the ground.

This will allow access to monitor and correct any problems that might come up. An entrance hole should be 1 1/2 inches in size.

I can guarantee House Sparrows will be a problem and we should make every attempt to keep them out. Removing nests, trapping and all legal action should be taken.

The better you control House Sparrows, the better your chances will be of attracting and hosting these birds near you.

More detailed information about hole size, house size and more can be found at Bluebird House

When Do I Clean Out Nest Boxes? Should I Clean My Bluebird House?

The quick answer regarding cleaning houses is: it's up to you.

It's different depending on where you live. blowfly and mite infestations can be more of a problem in humid areas.

A good idea would be to check for blowfly and mite infestation before just throwing out the nest.

This should happen as soon as the first brood leaves and after any successive broods. The following steps are enough.

With gloves and a mask (for your protection) gently remove the nest and check for blowfly and mite infestation.

If none, let the breeze take care of feather dust and replace the nest for the second brood.

If the nest is heavily soiled or infested, it might be a good idea to remove the contents, place them in a bag, or burn them in your burn pile.

Recent Fledglings Visiting Birdbath

Some people recommend a cleaning solution of 10 percent bleach to water ratio to scrub the house.

That's up to you and recommended at the end of the season or before the birds' return. Rinse well if using bleach.

Sometimes Bluebirds build nests on top of the existing nests. This puts them closer to the entrance hole and at a greater risk of predation. The lower nest may need to be removed in this situation.

They may use nest boxes up to 4 times per season.

For winter roosting, you can add a layer of straw for insulation to help the birds survive wintry nights. Sometimes the birds will add additional material in winter.

What is the Diet

In summer, Bluebirds primarily eat insects. Eighty percent of their diet comes from this source and is an important part of the youngs diet.

Their winter diet also includes insects but will be supplemented with other foods such as wild berries and fruits from small trees and shrubs.

You may want to try placing dried fruit and chopped peanut kernels on a platform-type feeder.

There are other ways to lure these birds both in winter and summer, the best of which is to offer them mealworms in a Mealworm feeder. They love mealworms. You can even raise your own. (link below)

You can offer live or dried mealworms. Place them in a tray feeder or a specially designed feeder so that other birds don't get to them before the Bluebirds.

Mealworms are inch-long larvae, with brown, crusty shells, available from pet supply stores or online.

Do They Mate for Life?

While they typically form strong pair bonds during the breeding season and actively raise their offspring together, Eastern Bluebirds do not mate for life in the strictest sense.

Extra-pair copulations have been observed in some cases, where individuals may engage in mating with birds other than their primary partner.

Nonetheless, on the whole, they are considered socially monogamous and often mate for the duration of their breeding season and may re-pair seasonally.

During this period, they work together to build nests, incubate eggs, and raise their young.

Winter Behavior

Providing Dried Mealworms in winter is a good idea. They are inexpensive and last a long time. You'll also be helping other birds in the winter.

Since bluebirds remain in winter in a lot of places, a Heated Birdbath can supply the open water they need to survive.

An open water source is critical during cold weather, as most water is frozen. All life needs water year-round.

Provide a Roosting House For Your Wintering Birds

How Do They Stay Warm During Winter

Bluebirds will also roost in birdhouses in winter. Sometimes 6 or more will enter a house at one time.

A roosting house has an opening at the bottom which helps keep the heat from rising and going out through the entrance hole of a traditional nest box.

Many folks see the birds entering the birdhouse and think they are nesting. Usually, they are just checking it out for later in the evening.

They may even bring in what looks like nest-building material. Most likely it is just to create more warmth.

It may surprise you to see these birds in February and March in 10-degree weather, but it is more common than you might think.

Yes, even in New York and in Minnesota. Nesting will even begin in March in these areas.

Nights below freezing are tolerable for these birds without any problems. Even eggs being incubated will be fine as long as the adults are there to take care of things.

Do not interfere during these times. Any eggs not viable will be removed and they will lay a new clutch.

Lifespan

The lifespan of the average Eastern Bluebird is 6 - 7 years in the wild. Maximum lifespan recorded, 10 years 6 months.

Check out this page where visitors talk about seeing Bluebirds in Winter

Additional Information:

Attracting Bluebirds To Your Yard | Bird House - What You Need To Know

Check Out These Gift Ideas | Setting Up A Trail of Birdhouses

Mountain Species | Raise Your Own Mealworms

Watch Videos of This Bird

History and Facts

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