Eastern Bluebird Nesting (Behavior, Eggs, Location + FAQs)

Eastern bluebirds are one of the species most likely to make a home in a backyard nest box, requiring the shelter and safety of an empty nest to raise their young.

Our Eastern Bluebird Nesting Guide explores how to choose a site and build a nest, and examines whether old nests are being repurposed for future bluebird brood. Read on to learn everything you need to know about the nesting habits of the Eastern Bluebird!

Where Do Eastern Bluebirds Nest?

Eastern bluebirds are cavity nesters and will only build their nests within the safety of an enclosed space, such as a hollow in a tree or a purpose-built nest box. To attract bluebirds, the nest box should be well positioned about 150 to 180 cm (5 to 6 feet) above the ground, with its entrance facing away from the prevailing winds.

A pair of Eastern bluebirds bring food back to their nest

What does an Eastern bluebird’s nest look like?

While eastern bluerobins will utilize existing natural and artificial nesting cavities, both will contain a nest platform that the female carefully crafts from a loose cup-like structure woven using grasses, twigs and bark.

These structures are built into the bottom of a cavity or nest box, and if the cavity has been used in a previous breeding attempt, a new nest will be built on top of the old grass structure.

Close up of eastern bluebird nest from inside the nest box

How Big Are Eastern Bluebird Nests?

The burrows used by bluebirds are usually 10-12 cm (4-5 in) wide and at least 20 cm (8 in) deep. Bluebirds at ease in nest boxes thrive in boxes 20 to 30 cm (8 to 12 in) tall with entrance holes about 3.8 cm (1.5 in) in diameter.

What Time of Year Do Eastern Bluebirds Nest?

Nesting begins as early as late February, but is more common by March. Egg laying usually occurs in April, but for eastern bluebirds raising more than one brood, the nesting period will continue until later in the year.

Female eastern bluebird flies away from the nest box to feed the chicks

How Long Do Eastern Bluebirds Nest?

The length of time eastern bluebirds spend nesting depends on where the breeding area is located. The average incubation period is about 13 days, but can last from 11 to 19 days. For eastern bluebirds in the southern United States, the incubation period is slightly shorter than in the colder northern regions.

After hatching, the young bluebirds continue to be nursed by the female for 5 to 7 days, after which the female rarely remains in the nest for long. Between days 17 and 18, young bluebird chicks are ready to grow their wings.

Male Eastern bluebird removes sawdust from the nest

How do Eastern bluebirds build their nests?

Eastern bluerobins are one of the best known secondary cavity nesters, meaning they use an existing cavity that has been dug by another bird because they cannot dig a suitable cavity themselves. About 77 percent of eastern bluebird nests in natural caves were originally drilled by woodpeckers.

Eastern bluebirds are common nest box dwellers who line the inside of a tightly woven cup-like structure made of straw, hay, pine needles and bark, with the inner cup lined with softer grass and other materials.

Nest site selection is the job of the male eastern bluebird, but the female eastern bluebird builds the nest structure alone, gathering nesting material from the ground and molding it. Males occasionally carry nest-building material, but offer little assistance in building it.

Female eastern bluebird with nesting material in beak

When Do Baby Eastern Bluejays Leave The Nest?

Chicks emerge about 17-18 days after hatching. Once young Oriental bluebirds leave the nest, they will continue to be supported on the ground by the two parent birds until the female starts working on the next or second nest.

How many broods do Eastern bluebirds have?

One or two broods per year is the most common number for eastern bluebirds to rear in any breeding season, although it is not unheard of to try a late third brood, especially if the early nests were unsuccessful. In this case, the last clutch of eggs may not be laid until late August or even September.

Male Eastern bluebird feeding a hungry chick

Do eastern bluebirds nest in the same place every year?

It is common for eastern bluebirds to re-use previous nests, with studies showing that 26% to 44% of the birds return to their previously used nests. This is especially likely to happen when earlier broods successfully hatch.

To encourage bluebirds to use the nest box again, it is recommended to clear the contents at the end of the breeding season so that there is room for a new nest.

What do Eastern bluebird eggs look like?

Eastern bluebird eggs are sky blue or, in rare cases, white – about 4-5% of females. Egg shells are smooth, subelliptical, and 2.5 cm (1 in.) long. Clutches lay 3 to 7 eggs, with 4 to 5 being the most common number.

Nest with four oriental bluebird eggs

What month do Eastern bluebirds lay eggs?

April is peak egg-laying time for eastern bluebirds, especially for the first or only brood of the season. In rare cases, the earliest eggs may be laid in late February, and the most recent may last until mid-September for a second or, rarely, third clutch.

Do Eastern Bluebirds Abandon Their Nests?

Eastern bluebirds have been observed to abandon nests under extreme circumstances, including the death of a female, threat or disturbance from predators, or eggs that fail to hatch for any reason.

In the event of nest abandonment, Eastern bluebirds will often move to new nesting sites to attempt to breed again.

Eastern bluebird chick peeking out of the nest

Do Eastern Bluebirds Use Nest Boxes?

Eastern bluebirds are one of the birds most likely to make a home in a nest box. Eastern bluebirds use nest boxes to raise their young during the breeding season and also double as sheltered perches during the winter.

If a nest box is re-used for a subsequent brood, a new nest will be built on top of the previous one, so it is advisable to clear the old nest after it has been abandoned so that the birds can benefit from maximum nesting space if they Claim boxes for future nesting sites.

Nest boxes attached to poles, 150 to 180 cm (5 to 6 ft) off the ground, are ideal for bluebirds because they protect them from predators and competing birds such as house sparrows.

Eastern bluebirds are among the birds most likely to utilize nest boxes

Are Eastern Bluebirds Nesting in Backyards?

Backyards are a popular choice for eastern bluebirds, where they can build their nests and raise their young. Eastern bluebirds frequently use nest boxes, seeking nests with easy access to well-stocked bird feeders and vegetation that may attract the insects that make up a large part of their diet.

It turns out that the hollows that woodpeckers dig in trees, especially oaks, are also popular with eastern bluebirds, which seek a safe space to raise their young.

Do Eastern bluebirds nest on the ground?

Only on rare occasions have Eastern bluebirds been known to nest anywhere on or near the ground, cup-shaped nests built on tangled tree roots, although these are indeed exceptions and no examples have been observed in recent years . Typical nesting sites are between 0.6 and 15 meters (2 and 50 ft) above the ground.

A pair of female (left) and male (right) eastern bluebirds are nesting

Do Male Eastern Bluebirds Sit on Eggs?

Incubation of the eggs is the sole responsibility of the female eastern bluebird. The male takes on the role of the nest protector, fending off any threats to his mate and eggs or young. The male Oriental bluebird also continued to provide food to the female while she was incubating her eggs, and was unable to leave the nest unattended.

What trees do Eastern bluebirds nest in?

Eastern bluebirds are cavity nesters, but are unable to dig their own burrows, relying on naturally formed holes in tree trunks or abandoned cavities dug by woodpeckers. Oak is one of the most commonly used tree species for eastern bluebirds.

Where Do Eastern Bluebirds Nest At Night?

Empty tree hollows or abandoned nest boxes provide eastern bluebirds with shelter and safe overnight habitat, protecting them from extreme weather conditions and opportunistic attacks from predators.