When Do Bluebirds Lay Eggs

Seasonally, bluebirds eggs in April and May (possibly in March for southern states). After the nest is complete, a bluebird may begin laying immediately or after a “bluebird honeymoon.” She will usually lay one egg per day, often in the mornings. Therefore, it is important to consider these things and more when monitoring or hosting your bluebirds.

Bluebird egg-laying information

Why should you know when bluebirds lay eggs

Bluebirds are such beautiful birds and very interesting to watch, so learning about their nesting behavior and when they lay eggs can be very exciting.

Furthermore, knowing the timeline will help you monitor, protect and know what to expect when it comes to your bluebirds.

If you’ve noticed bluebirds carrying stuff to your bluebird box, start to mark your dates, and be sure to monitor nest progression daily.

Once the nest is complete, the mother bluebird may lay her egg immediately or her and her mate will have what bluebird landlords call a “bluebird honeymoon.”

During a so-called bluebird honeymoon, you can expect an absence of a few days up to a few weeks before the female returns to lay her eggs.

Even during this absence, nest monitoring is important because sometimes another bird might take over the nest. If its another native bird, do nothing. DO NOT evict that bird.

In fact, if you happen to get a chickadee, it is very important you add a hole-reducer to protect them since they’re on more of a decline than bluebirds. After adding a hole reducer, set up another bluebird box for your bluebirds at least 40 feet away from the original.

But if you notice house sparrows or European starlings coming to the nest box, it is vital you take quick action.

House sparrows and European starlings are invasive birds who kill native cavity nesters like bluebirds and chickadees for nesting spots.

Once they start singing on a nest box or bringing stuff to the box, you can assume they’re fairly bonded to the box.

In this case, deterrents like monofilament or sparrow spookers won’t work. These birds are relentless.

You also don’t want them nesting in your yard, producing more invasive birds.

The only way to deal with them is to trap and euthanize. If you’re not up to the job of euthanizing, look up local falconry groups and contact falconers or message wildlife rehab centers who might be willing to take them live.

After your bluebirds return, the mother should begin laying her eggs.

That first egg-laying date is important because it’s also an action marker on your part.

Usually, a bluebird becomes less likely to abandon a nest box if make additions to it once there is at least one egg laid. So if you were intending to add a wren guard or sparrow spooker or even monofilament, this is the first point at which you can take those important steps.

After all of her eggs are laid, she will begin consistently (but not continuously) sitting on her eggs – incubating them. She waits until the last egg is laid so that the eggs will all hatch on the same day.

Ways to care for a nesting bluebird

There are many ways you can care for and protect nesting bluebirds. This includes adding a baffle to the pole, supplementing mealworm with calcium, keeping feeders far from an active nest, and ethically monitoring nests.

Laying an egg takes an immense amount of resources, particularly when it comes to calcium. One study determined that the eggs in a single clutch of blue tits was composed of more calcium than in the female’s skeleton (Perrins & Birkhead, 1983).

While calcium is pretty abundant, it’s actually lacking in meal worms. Additionally, poor soil and acid rain can also impact calcium availability for birds.

A simple way to help bluebirds laying eggs is to save your egg shells. When you’re ready, sterlize them by baking them at 200 degrees (F) for half an hour and then finely crush them (pulverize)

Manual pulverization isn’t hard if you have good tools. We recommend this mortar and pestle from Amazon*.

Add the ground egg shells directly to mealworms or to seed.

Speaking of birdseed, it is very important you do not place feeders near active nests. Bird feeders attract many visitors, some may not be too friendly.

In fact, you’d be surprised at the wildlife that visits your yard at night, and they can be especially drawn to your birdfeeders. If they’re drawn to a feeder placed near a nest box, it might not take long for them to get a sniff of some other yummy treats – your birds!

Though good seed selection can minimize the threat of house sparrows and starlings, they will eat black oil sunflower seed and even nyjer seed. Rather than risking it, move your feeders or take them down altogether.

As we mentioned, there is a wealth of wildlife in your yard, and they’re very stealthy. Adding a good stove-pipe baffle can make a huge difference.

We have a really helpful guide that details how to choose a baffle. You can also find appropriate baffles on our site.

Finally, ethically monitoring your nest is another great way to contribute to bluebird success.

We have a really good guide about bluebird nest monitoring, but in general here are a few considerations:

1. Monitor during times the mother bird is away from her nest.
2. Always knock on the box before opening the box. This allows the mother a chance to fly off.
3. Do not spend more time at the nest box than necessary. You can use your phone to snap a few pictures.
4. Once bluebirds are about 10 or 12 days old, do not open the box. It could cause premature fledging out of fear.
5. Nest box cameras are a really helpful way to monitor. Blink cameras from Amazon* are one of the most widely used cameras for inside a nest box.

*Contains affiliate links. If you order a product after clicking these links, we earn a very very small commission that helps support our efforts and does not cost you anything extra.

References

Perrins, C. M., & Birkhead, T. R. (1983). Avian Ecology.,(Blackie & Son: London.).