Why Birds Abandon Their Nests With Eggs – 4 Common Reasons

Each breeding season, concerned bird lovers panic when they come across a nest with eggs but no parents in sight.  Are the parents gone for good? Why do birds abandon their nests with eggs? Can I save the eggs? What can I do to help? These are all common questions you may have if you come across a deserted nest. In this article we will talk about why this might happen, what you should and shouldn’t do, as well as answer some other frequently asked questions about nests with eggs.  

(Image: Robert Lynch | publicdomainpictures.net)

4 reasons why birds abandon their nests with eggs

So you’ve noticed a nest with no parents in sight. Let’s look at the most common causes. 

1. They have only gone to get food and will return

Momma still has to eat! Parents have to periodically leave the nest to get food for themselves. While incubating eggs this could be up to about 30 minutes off the nest. However before incubation, during the egg laying period, birds don’t actually have to spend much time on the nest at all! 

Many birds won’t begin incubating their eggs until the very last egg has been laid. This is a strategy to try and get all the eggs to hatch close together, so the babies aren’t all developing at different rates while the parents are trying to take care of them. Most of your backyard birds will only be laying one egg per day. Let’s say their total number of eggs will be four. It could take 4-5 days before they are done laying all their eggs, and during that time period they don’t need to sit on the nest. 

Some adult birds may even intentionally stay away from the nest for long periods before incubation, so that they don’t draw attention to the nest location. Eggs can be viable for two weeks before the adults need to start incubating them! So if you see a nest with eggs and no parents, it may not be abandoned at all, they just haven’t started incubating yet. Even when parents aren’t sitting on nests, they are still monitoring them. 

American robin sitting on the nest (Image credit: birdfeederhub.com)

2. The adult birds were killed by a predator 

While unfortunate, sometimes the parent bird is killed while away from the nest. Birds have many natural predators such as cats, snakes, foxes, raccoons and even larger birds such as hawks.

In some cases if one parent is killed, the other parent will try to take over nest duties. However for most songbirds the males are not equipped to incubate eggs. Some species are very collaborative with the males helping gather food. If a male partner is killed, the female may judge that she cannot handle the workload of incubation and feeding on her own and give up the brood. 

If you have nesting birds in your yard you may want to consider keeping your kitty indoors until the young have left the nest. Doesn’t hurt to give a little extra help to mother bird by making sure your pets don’t harm or scare them away. Which brings us to our next point. 

3. They were scared away by predators or humans

Most birds have a strong instinct to stick with their nest. A momentary scare usually isn’t enough to spook them for good, and they will return.

But if they feel overly disturbed or harassed, they may give up and desert the nest. This disturbance could come from competing birds trying to get at the eggs, animal predators looking to raid the nest, or humans being too curious and getting too close for comfort. Hatching eggs and raising babies is a lot of work! Birds aren’t going waste their time and energy if they feel the nest site is no longer safe and the chance of their young surviving is low. 

One bad encounter with a predator, even if they bird is successful in defending their nest, may be too much if they fear the predator will return. Humans getting too close to the nest can also cause a lot of stress and make the birds give up, fearing the safety of their nest location has been compromised. 

Some species are more easily scared away than others. Also, younger birds who are having their first nesting season might be less experienced and more apt to desert a nest when scared. 

Do your part and steer clear of a nest if you spot one. If you want to observe, view nests with binoculars from a safe distance. Depending on where the nest is built, this may mean avoiding a certain section of your yard for a few weeks, or only walking by minimally. The birds will thank you.

4. Insect infestation

If a nest becomes infested with flies, ants or mites, it may be so unbearable and unhealthy for the parent sitting on the eggs that the nest is abandoned. The parent may also judge that the insects would reduce the chances of survival for any young that did hatch so much that it’s not worth investing the energy to continue to incubate the eggs.  


What to do if you find an abandoned bird’s nest with eggs 

The Cornell Lab of Ornithology suggests you follow the one month rule:

“The eggs of most birds will remain viable for up to two weeks after being laid even before they are incubated, so as a general rule, you should wait at least one month after the expected hatch date before concluding that a nest is abandoned.

What you should do  

  • Monitor the nest for at least one month after the expected hatch date of the eggs before making a conclusion it is abandoned. 
  • Give it as much space as possible. You may be getting too close to the nest and continuing to scare the birds off. Try to avoid walking around the nesting site. If the nest is in a high traffic area, try to avoid that spot in your yard for awhile to give the birds a chance to feel more secure. 
  • Keep pets indoors, your dogs or cats may be spooking them.
  • If you were watching the nest and have good reason to believe something happened that might have caused abandonment, call a local wildlife rehabber for advice. (see link in our conclusion below)

What you shouldn’t do 

  • Don’t move eggs from an “abandoned” nest to another nest. Depending on the species, some birds may not accept a foreign egg. Also, birds stop laying at a certain number for a reason. By adding more mouths to feed to the nest you may over tax the mother birds ability to take care of too many young, jeopardizing the health of all of them.  
  • Don’t move the nest. If the parents return, they may not recognize or accept the new nest location.
  • You shouldn’t attempt to pickup or touch the eggs, they are so easy to damage. 

Bird nest FAQ

Will birds return to a disturbed nest?

Most of the time yes, the instinct to stay with the eggs is strong unless there is a lot of disturbance. 

How long can bird eggs be left unattended?

Most bird eggs will remain healthy for up to two weeks before incubation starts. During this pre-incubation period, birds may leave the nest for long periods during the day. After incubation has begun, parents can still leave the nest but only for a maximum of approximately 30 minutes. 

Why should we never touch a birds nest?

Firstly, you don’t what to scare a parent off the nest if you can help it. But even if the parent is not on the nest, you shouldn’t assume it is abandoned.  If it’s not, you could be disturbing and damaging the eggs and the delicate embryos inside.

Eggs can be easily cracked, and jostling could damage the developing embryo. Newly hatched birds are equally vulnerable to injury, they are very fragile. You also don’t want to be leaving human scent near the nest. The birds won’t mind, but it could attract other mammal predators. 

How do I know if a bird nest is abandoned?

The only way to know is constant monitoring, for at least two weeks. 

Why would bird eggs be on the ground?

Some birds, like the killdeer, actually lay their eggs on the ground without anything that really resembles a “nest”. 

Competing birds such as cowbirds and house sparrows may remove eggs from another birds nest. Often they will break or peck a hole in the egg, ruining it’s chance to hatch.

Adult birds are often aware if one of their eggs is infertile, and may remove it from the nest to make room for the others. 

A predator may have snatched the egg and dropped it. Squirrels, crows, blue jays, raccoons, foxes and snakes will nab eggs from a nest.  

Wind or a storm could have knocked it out of the nest. 

Killdeer with their eggs, just in a small depression in the ground, not much cover. (Image: USFWS Midwest Region | flickr)

What should I do if I found eggs on the ground?

If you KNOW the egg fell out of a nest and can easily reach the nest location, you can carefully pick the egg up and put it back. Eggs are very fragile, use extremely light handling. Your “scent” will not bother the adult birds. If you do this and the egg shows up on the ground again, leave it. The adult is removing it for a reason. 

Outside of the above scenario, it is best to just leave them alone. Fallen eggs are most likely broken, or the developing chick inside has sustained injuries from falling, or the egg has been out of the nest for too long to maintain its proper temperature. In all cases the chance of survival for the chick are basically zero. 

How do you tell if an egg is alive or dead?

To the untrained eye, it’s impossible to be sure. Color, weight, smell and temperature are all clues. But again, if you don’t know what “normal” is, you have nothing to compare it to. If there is any sign of a crack or hole, the egg is not viable. 

Can you hatch abandoned bird eggs?

No, you should not attempt this.

Only those with licenses / permits are allowed. It is otherwise illegal to possess eggs of a native bird under the Migratory Bird Act.

Secondly, it is very difficult to hatch a bird egg! If an egg has truly been abandoned chances are that by the time you found it, it has already been cool for too long and is no longer viable. Even eggs that are still viable have very specific requirements for temperature, humidity and how often they need to be turned. For each species of bird, these requirements are different. 

If the egg did hatch, dealing with hatchlings is also a very difficult task. They need special diets and to be fed a very specific amount of food, every 5-15 minutes all day long, and kept at certain temperatures. Also, you cannot take the place of a parent when it comes to teaching young birds how to take care of themselves in the wild, and too much interaction with humans at this critical age often set them up for failure surviving on their own. Not to mention it is once again illegal to possess these birds unless you are a licensed rehabber. 

Is it OK to remove a birds nest in some cases?

Sometimes birds build in less than optimal locations, like under the roof of this carport! (Image: birdfeederhub.com)

Only under certain conditions.

Is the nest empty? If yes then it’s ok. It is not illegal to move a “non-active” nest, which is a nest without eggs or young in it. If you catch birds building in a bad spot (your grill, over a frequently used door jamb, etc) you can remove the nesting material and encourage them to try again elsewhere. If the nest is completed you can try moving it to a safer spot close by, as long as there are no eggs or young in it. Next season, you can try and keep them from building again with some bird repellent tactics

Is the nest a non-native species? European starlings and house sparrows are not native to the United States and are not protected by the Migratory Bird Act. Their nests can be removed at any time, even with eggs or young.

An old nest no longer in use can be removed. Such as a nest from a previous year or in the fall/winter after the young have moved on. 

In many cases a nest with eggs in it, if moved, will be abandoned by the parents. That doesn’t always happen, but it’s definitely a risk so why chance it? If you desperately need to move an active nest and simply cannot work around it, call a local wildlife rehabilitator. They can give you the best advice and have the permits to do so.  

How do I know if I’m too close to a bird nest?

Some birds will give you signals you are too close. Birds like the northern mockingbird, blackbird and blue jay will aggressively dive bomb your head. They aren’t trying to inflict injury, just to chase you away.

Killdeers will put on a show of pretending to have a broken wing to distract you and lure you away from where the nest site is.

Some adult birds can sound a call that the babies instinctively know means “be quiet and still”. Once the babies are settled down the adult will fly away from the nest and make a series of loud vocalizations and movements trying to distract from the nest and lure potential predators away. If one of your backyard birds seems louder, screechy and more agitated than usual, they are probably trying to draw your attention away from a nest. 

But many birds just become very still and hunch down low in their nests, trying to go unnoticed. Don’t assume that if a bird is staying in the nest that you aren’t bothering them. If you can keep a good distance and observe the nest with binoculars that is best. Try and stay ten feet away, and if parent gets spooked and flies off, leave the area quickly and wait at least 24 hours before walking by again. 


Conclusion

As much as you may want to help the birds you love in your yard, most of the time the best thing you can do is to leave a nest alone. Depending on where the bird is in the egg laying cycle, they might just not be incubating yet. It can be hard to tell if a nest is truly abandoned and if you try and take or move the eggs and the parent comes back, it goes from a rescue mission to a kidnapping, even if you had good intentions.

It is much harder than people think to hatch an egg or raise a young bird, and the best thing you can do if you are really concerned, in our opinion, to contact a wildlife professional. 

Click here to visit the Humane Society’s page listing wildlife rehabbers in each state. 

It’s easy to get mad when a predator attacks a nest, or want to help if you think eggs or young have been deserted. But that’s just how things in the natural world work. Many birds will face failures in nesting, but they can learn and try again. Unfortunately when untrained people intervene, it often does more harm than good. 

But you CAN help birds in many ways! Donate to a local wildlife rehabber as most are volunteers. Join a local birdwatching club and help advocate for birds in your community. Support wild birds by making your yard a pesticide-free welcoming habitat with food, water and native plants. 

 

About Melanie

Melanie has been a birding hobbyist for years and loves feeding and photographing birds of all types.

2 thoughts on “Why Birds Abandon Their Nests With Eggs – 4 Common Reasons”

  1. I have a question-I have a blue jay nest in my back yard..at one time it had 4 eggs in the nest. It has been about 7 days since they were laid. Mommy birds is around sitting on the eggs off and on..this morning I notice there were only 2 eggs in the nest-no tracing or sight of the other two eggs and no hatched babies..what could of happened to the other two eggs?

    Reply
    • Missing eggs probably means they were snatched by a predator. All sort of mammals, snakes and other birds will try and grab eggs. We wrote a short article about it here. Hopefully if mom is still around that means she still feels safe enough to try and hatch the remaining two eggs. It takes about 16-18 days for blue jay eggs to hatch.

      Reply

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