Quick Answer
It is generally not recommended to remove unhatched bluebird eggs from the nest. Here are some quick answers to common questions:
Will abandoned eggs hatch?
No, unattended eggs that have been abandoned by the parents will not continue developing and hatch on their own. The eggs need the parents’ constant incubation in order to hatch.
How long does it take for bluebird eggs to hatch?
Bluebird eggs typically hatch after 13-16 days of incubation by the parents. If the eggs are unattended for an extended period, they will not hatch.
Should I throw out unhatched eggs?
It’s best to leave any unhatched eggs in the nest. Removing the eggs can disturb the nesting site and bluebird pair. The parents may lay a new clutch in the same nest.
Understanding the Bluebird Nesting Cycle
Bluebirds are cavity nesters and readily take up residence in manmade nest boxes. Here is an overview of their typical nesting behaviors and timelines:
Nest Building
– The female builds the nest over 2-6 days out of grass, pine needles, stems, and feathers. She creates a cup-shaped nest at the back of the cavity.
Egg Laying
– Bluebirds lay one pale blue egg per day, usually in the early morning.
– Clutch size is typically 3-7 eggs.
– Egg laying takes 6-8 days to complete.
Incubation
– Both parents take turns incubating the eggs.
– Incubation lasts for 13-16 days.
– The eggs must be continuously incubated in order to develop and hatch.
Hatching
– The hatching process takes 12-36 hours from the first pecking until the nestling is free.
– Eggs typically hatch in the order they were laid.
– All eggs in a clutch do not always hatch. Some may be infertile or contain nonviable embryos.
Nestlings
– Parents feed nestlings for 16-22 days until fledging.
– Nestlings are fed insects, spiders, fruit pulp and seeds by both parents.
– Nestlings grow flight feathers and increase in size quickly.
Fledging
– The nestlings leave the nest at 16-22 days old, able to fly short distances.
– Parents continue caring for fledglings for 2-3 weeks after they leave the nest.
Reasons Bluebird Eggs May Not Hatch
There are a few reasons why some bluebird eggs in a nest may fail to hatch:
Infertile eggs
Some eggs may be infertile and never develop embryos. This can happen if the eggs were not fertilized or there are genetic issues with the embryos.
Embryos died before hatching
Developing embryos may die from genetic abnormalities, injuries to the egg, improper incubation temperatures, or lack of turning.
Parents abandoned the nest
Bluebird parents may abandon a nest for several reasons like human disturbance, predation, weather events, lack of food, or to renest elsewhere. The eggs will not hatch without incubation.
One parent dies
If one parent dies or disappears during incubation, the remaining parent may struggle to properly incubate the clutch. Some eggs may fail to develop fully.
| Reason | Explanation |
|---|---|
| Infertile eggs | Eggs were not fertilized or genetic issues |
| Embryos died | Genetic issues, injuries, improper incubation |
| Parents abandoned | Disturbance, lack of food, predation, weather |
| Parent died | Remaining parent cannot properly incubate |
Should You Remove Unhatched Eggs?
It can be tempting to remove unhatched eggs from an abandoned bluebird nest. However, it is typically best to leave any remaining eggs in place. Here are some reasons why:
Parents may return
If the bluebird parents abandoned the nest due to a disturbance or lack of food, they may return to incubate the eggs again. Removing the eggs eliminates this chance.
Eggs may still be viable
It can be difficult to tell from the outside whether embryos are still alive and developing inside an egg. Leaving the eggs gives them every chance to hatch if incubation resumes.
Future nesting deterrent
Removing eggs essentially cleans out the nest. This may make the site more attractive for the parents to renest again too quickly before raising their current brood. Leaving eggs deters renesting.
Monitoring hatchings
The number of unhatched eggs can provide information on the success and health of a bluebird pair. Removing eggs means losing data.
Potential legal issues
Bluebirds are native songbirds protected under the Migratory Bird Treaty Act. There may be legal issues with removing their eggs from an active nest.
| Reason to Leave Eggs | Explanation |
|---|---|
| Parents may return | Give chance to resume incubation |
| Still viable | Cannot tell if embryos alive inside |
| Deter renesting | Avoids overcrowding with new clutch |
| Monitor hatch rates | Data on pair’s breeding success |
| Legal issues | Protected under Migratory Bird Treaty Act |
What to Do With Abandoned Eggs
If you find abandoned bluebird eggs that are not going to hatch, here are some recommendations:
Leave the eggs in place
It’s best not to interfere and to leave the eggs untouched in the nest. Moving or removing the eggs may disturb future nesting.
Let nature take its course
Over time, the eggs will dry out, cool, and be broken down naturally. The bluebird pair may build a nest on top of the old eggs and clutch for their next brood.
Clean out only after nesting season
Discard old eggs, nesting material, and droppings only after nesting season is completely over, typically late summer or early fall.
Sterilize nest box to prevent diseases
Sterilizing and cleaning out a nest box after a season can help control parasites and diseases. Use boiling water, bleach solution, or Lysol to disinfect.
Use gloves when cleaning
Always wear protective gloves when handling old nesting material and eggs. The materials may contain pathogens that can transfer to humans.
Being patient and leaving things undisturbed is key. The bluebird parents often know what’s best for their reproductive success. Avoid tampering with their nesting site whenever possible.
Frequently Asked Questions
How do you tell if bluebird eggs are fertile?
There is no reliable way to determine if bluebird eggs are fertile and contain developing embryos without candling them. Even then, early embryos are difficult to see. It’s best to assume eggs are fertile and leave them alone.
What do you do with abandoned bird eggs?
Abandoned bluebird eggs should be left in the nest unless they are broken or damaged. Let the eggs be and leave it up to the parents to return. Removing healthy eggs should be avoided.
Do bluebirds reuse the same nest?
Yes, bluebirds will often use the same nest for multiple broods in one season. The female may add a new nest lining over the old one. It’s important not to remove old eggs so parents keep using the site.
Can you help a baby bird hatch?
No, you should never attempt to help hatch a bluebird egg or pull a chick from an egg. This can harm the embryo and prevent normal hatching. Allow the egg to hatch naturally with parental incubation.
How do you tell if a bluebird nest is abandoned?
Signs of an abandoned bluebird nest include missing parents, unchanged eggs over several days, dead nestlings, cold eggs, and a nest box taken over by other species. The parents will not leave eggs long without good reason.
In Conclusion
Unhatched eggs are a natural part of bluebird breeding. It’s best not to interfere and to leave any eggs undisturbed in an abandoned nest. Removing the eggs destroys their chances of hatching if the parents return, and risks permanently deterring the bluebirds from that nest box. Monitor the nest from a distance, and allow the bluebird pair to decide the fate of their own eggs. With time, nature will reclaim the nest for future use. Be patient and resist the urge to tamper with the bluebirds’ nesting process. Trust in the parents’ instincts to do what’s right for their brood.
