Maggie, I am so sorry for your loss. It's devastating, especially so close to fledging. Have you had much rainy, cool weather lately? For the last couple of years I have lost several first nestings on the trail and I attribute it to a lack of insects during long spells of wet weather. As the chicks grow, they need more and more food. Also, sometimes hypothermia is a problem if the nest becomes wet. We had rain for about 10 out of the last 14 days and I was happy that there were no hatched chicks on any of the trails except home and school, and I supplemented feeding in both those places with mealworms.

The amazing thing about our beloved bluebirds is that they will not give up. You might consider cleaning your nestbox thoroughly, rinsing with a bleach solution (just in case the deaths were disease related) and allowing the box to dry completely before closing. Fingers crossed that your pair chooses your box for round 2.
Kathy

So very, very sorry for your loss. Tragic indeed.

Linda...

Dreaded pesticides. That is a topic that is addressed with each of my neighbors who want a nestbox. Bugs and a few weeds are a good deal for not poisoning ourselves as well as the birds. Thankfully, more and more people are realizing the health risks and impact on nature. It's sad your blues paid such a high price.

Linda

If it was pesticides, how come the parents didn't die. Don't get me wrong, I am very glad the breeding pair is fine. I was just wondering. It may have been something else. I too am sorry for the loss of the babies. I hope u can figure out what happened. So sad!!

Karen

I was reading on the internet one day about the use of pesticides and from what I read it said they normally do not kill adult birds however they can make them sick for a bit. However pesticides can and will kill baby birds as their systems aren't as strong as an adult. So it could have been pesticides, have any of your neighbors had their lawn sprayed? So sorry the babies were lost, hopefully the adults will start a new nest soon.

Donna

I am so sorry. The first clutch this year consisted of 4 eggs. 3 never hatched. The one that did died on the 15th day. Like you I have no idea what killed him.

There are so many strong pesticides out there and here people use them freely. Especially on the fireants. This year ticks are a problem and I can only imagine what's going on there.

I burned the nest and dead chick, and cleaned the box. The parents built a nest immediately and I now have 5 more eggs. I'm making sure I have a mealworm supply to supplement feeding. This seemed to be what made a big difference last year.

Again, I'm so sorry. I hope you and I both have better results the 2nd go round.

tara

I am so sorry. My guess would be pesticides. I've lost baby dees in two different nestings and I think it was pesticides.

Like I said Karen the babies eat so much more than the adults in proportion to their weight b/c they are growing.

we have watched this last family of blue birds babies die one by one. Of five only one is trying to survive. No signs of attacks by bird or insect. what is killing these birds? We are at a total loss here.

I too lost a nest of baby blues, and was really disappointed. I was curious as to what happened. No sign of predator or disease. Curiously, my neighbor found the female dead in her driveway about the same time. Some have said that without both parents to feed them they sometimes starve. I'm hoping that he will find a mate and return next year. We are so happy to finally have them coming after trying for 10 years. Feeding them dried meal worms helps them in fledging season.

I had 6 baby blue birds in our blue bird house and noticed that the sparrows were hanging around. I noticed that the male blue bird chased them off once and then looked in the nest and just left. I check and all babies were dead. I didn't check them I just disposed of the whole nest babies and all. Now sparrow are building. How do I stop them. This house as always been full of blue birds and I've not had this problem in this house before.

caye61542. We had hoped that the bluebirds would return again this spring and they did. However the english sparrows are relentless. They would harass the bluebirds and keep them from nesting and take over the nest. Finally after I saw that the bluebirds had nested elsewhere but were returning for the meal worms i put out for them, I was pleased. I then put a cover over the nest holes to keep the sparrows from nesting. However, eventually a pair of mockingbirds showed up and are harassing the bluebirds at the feeders and keeping them from getting at the food. I'm positive the bluebirds would have nested here this spring if not for the sparrows. English sparrows are a constant challenge. I will try again next year. I don't know what I will do about the mocking birds. I have done some research on the subject of english sparrows and bluebirds and it seems universal that sparrows are a constant annoyance to bluebirds. Other than removing the sparrow nest from the box and closing the hole so sparrows cannot return, and wait for next year, I don't see any resolution to the problem. So sorry for your problem. Hope some of this helped.

Hi all- so sorry for all of you that have mystery deaths of your bluebird babies. When they're younger, I suspect hypothermia or other things, but when they're older with no signs of foul play, etc, I definitely suspect pesticides. Last year, I had 3 that fledged (one died in box) & only one could fly. The other 2 were hopping around in my courtyard & died within 2 days (was depressed for a month). I had sprayed a citrus spray that was supposed to be safe about a week earlier, but evidentially not. So so sorry for your losses. Don't give up!

Will leave another message about house sparrows.

Nicole

Caye61542, so so sorry that you lost your baby blues from those nasty HOSP's. Never never let them nest in your bird houses. Always put up a sparrow spooker after 1st egg has been laid by bluebirds or any others that may nest with you. If you're not familiar with spooker, there is plenty of info online. Most people make theirs, but I bought mine. Make sure you remove it after babies fledge, so HOSP's don't get accustomed to it. They are really effective, but not always.

The other thing that's critical when you have a HOSP problem is to get a Van Ert Trap installed inside your bluebird house (can order online & very easy to install). You can only use this when no birds are nesting. It can be removed during this time. What happens is when the HOSP enters, it sets the trap off & covers up the hole. Then, you have to get a big bag (I have large laundry bag with drawstring so I can see the bird & make sure it was a HOSP that I caught) & put all the way around house & open door for HOSP to escape. They will come out quickly, so make sure they don't escape. It's key to monitor hourly when you use this trap because you could trap bluebirds or other native birds as well & don't want them to die in box. You will then need to dispose of HOSP & try to trap the mate as well. I know some people don't want to dispose of them, but how else are you going to keep them from killing your bluebirds? There are humane ways to do it. The Sialis site outlines the entire process for you & gives other tips on how to control HOSP's. It's a personal choice, but definitely invest in a sparrow spooker. People that have serious HOSP problems trap multiples in a repeating trap that they use a decoy & millet to get them trapped. I'd be getting rid of that nasty HOSP that killed your babies! Best of luck!

Nicole

I have effectively blocked the sparrows from nesting. I saw that the blues were nesting elsewhere, so kept the feeders up. They rely on them. However, I now have encountered another problem. Nasty mockingbirds. They chase the blues from the feeders. But the blues do get to the feeders. Not as much as before. I'll keep working on that and wait for next year.

Thank you to all who have given me ideas as to how to help the blue birds and discourage the house sparrows. I am removing the house sparrow nests as soon as I see one and the blue birds are still hanging around and watching but they don't have a chance to build. And of course when I go to the box to check for a nest the blue birds fly away too. I am going to try the sparrow spooked as soon as I find one. Thank you again.

Again, caye61542, so sorry about your babies. Those HOSP are just pure evil! For you & Tom both, I'd seriously consider the Van Ert trap so that the bluebirds can nest with you successfully. The sparrow spooker is a must though!

Tom, I've got the same problem with bullying Mockingbirds & Robins hoarding the mealworms. You can get a specific feeder (Duncraft has some good ones online) that only allows the smaller songbirds to get to the mealworms. There are 2 types- one that's caged & one that has plexiglass on both sides & a hole for them to enter & exit. I like the caged one so that birds don't run into the plexiglass thinking that it's open. It should keep those Mockingbirds from getting your mealworms over the bluebirds. Hope that helps!

Nicole

Thanks Nicole. I will keep the nest boxes covered for the rest of the year and try again next year. The feeders you referred to are a help, as I already have them. However, the mockingbirds are still able to hang on to the little ledge and flap their wings to keep balance while they poke their head in and get the worms the blues have scattered around. I am considering modifying the one feeder by taking away a little more of the ledge. I have no problem a all with robins. The blues are still getting some of the food. I try to not fill the dish as high to avoid overflow. Has helped. They did not go for the plexiglass feeder.

Thanks for your input.

For the past two times this year I have found dead baby bluebirds just ready to fly away. Today I found the latest two. For several days they have been very active and I thought they'd fly immediately. But they never seemed to. Today, at noon the were still in the nest but not as active. And the last two times the parents brought food they did not come to the birdhouse opening for it. Several hours later, I finally opened the box and found them dead. There were two large flies dead inside also and the nest was pretty muddy looking inside. It's a prefab bluebird house of probably some sort of fabricated material. I don't believe my immediate neighbors spray their yards. But I am heartbroken, having watched the parents work so hard. This is the third nesting this year. I hope at least one lived in the first one this spring. I did not find a fully formed dead bird in that one, only a couple of not-quite blobs left. I am wondering if I should just take the house down? Could it be the house? Do flies somehow kill baby birds, and if so, how do you keep them away? I am heartsick.

We have successfully followed advice in this web link to control English/house sparrows from our bluebird nesting boxes:

https://www.hunker.com/13406198/how-to-sparrow-proof-a-bluebird-house

We like the "fishing line curtain" best. Charles

I read that you should buy a second bluebird house and put it in another location for the sparrrows. I did this and the bluebirds went to the new house but the sparrows never built a nest in the old house and I haven’t seen the sparrows in a couple years. I have left both houses.

I lost 3 of my 4 Bluebirds. The ones left in in the nest had full feathers. We had a cold and wet spring here in central MD. Evidently the lone survivor is alive and well.

We live in southern MD. Our bluebird’s first brood of four chicks was successful. The second brood was 5 eggs laid from 27 to 31 May. Four eggs hatched on 13 June and one on 14 Jun. All chicks looked healthy and being fed by both parents through 16 Jun. On 17 Jun three were dead. The female got two out of the nest but could not get the third dead one out and just pushed it to the side. 18 Jun one of the remaining chicks was next to the dead chick but still alive, and it looked like the female was no longer taking care of it. 19 Jun the female abandoned the nest and the two remaining live chicks. We have had multiple fledglings over many years and have never seen anything like this. What happened and could we have helped prevent it.

I’m SO sorry to read about all of your losses…so sad…sigh… 10 years ago my neighbor gave us a bluebird house he built. He & his wife had several houses and hand fed the bluebirds after they laid new eggs. It was amazing to watch them! We never got any bluebirds to nest in our box until just 3 weeks ago, it’s interesting because my 91 yr old neighbor who gave us the box just died last year. We think he must of past the job on to us! We were thrilled to have the bluebirds nest in our back patio where we could watch them from our bedroom window each morning. I fed Dad live meal worms each day & he finally sat on my finger. But!!! Sadly 4 out of five babies just died suddenly! We are heartbroken😢 😭 I cleaned out the box yesterday not sure we’ll put it back up yet… It was SO much fun while it lasted we still feel very blessed to have had them in our lives and I think one day we will put up a new bluebird box or two.🙏🩵

Hosted many flegdings for years until new neighbors moved in who have mosquito service that sprays every two weeks. Luckily I had one brood of 4 that fledged before the spraying started. 2nd brood, 5 babies, 15 days old, didnt make it. I can only assume the parents fed them the contaminated insects. This happened last year too. I have no bees, fireflies or dragon flies anymore. This spraying is legal in NJ, nothing I can do about it except move!

I had nearly the exact thing happen this year (2025). This box had crisis last year when I found the nestlings wet, their nest soaked and berry seeds abundant. What I was told was that the parents were feeding them non-native berries because there weren't enough insects! I took the nestlings out, cleaned the box, replaced with a dry nest and supplemented with mealworms. Two males and a female ran nearly 100 mealworms into that nestbox within the next 20 minutes! It was a rescue mission. The nestlings all survived and fledged three days later. But this year, that nestbox wasn't touched until way late in the season. I was glad to see they were back, better late than never. But maybe not. Four eggs, four nestlings, all looked well. I checked them a day ago, providing rehydrated mealworms. I noticed some dog doo near where I put the mealworms. I wonder if that could affect the nestlings by contamination. I took the bos down and it felt light. I wondered if they had fledged but it was too soon. All four melding together and decomposing! This park is chemical-free, the only one in Orange (CA). All the other nestlings in the other five boxes had a good run. This was a special box and had yet another disaster this year! No evidence of foul play, no insects, etc. Another seasoned monitor told me it might be due to the male not returning, maybe killed in a fight, and the female abandons the nest. The nest box is down, washed out and waiting for a thorough cleaning. I hope they return to this box next season. We'll see. Very sad.