Kendra, I have lost nestlings to blowfly larva so if it were me I would be on the safe side and do a nestchange. It certainly can't hurt. If they were that bad in the TRES nest they are more than likely in the Blues nest too. I have never had blowfly in TRES nests but seem to always have some in the BLues especially during the second nesting. First nestings here are pretty low on blowfly larva but during second nestings...watch out! Good luck, have you ever done a nestchange before?

Donna

I would do a change to be safe. I checked my BBs nest the last day I could and didn't find anything. When I removed the nest there were a lot of larva. Yuck!

Thank you so much Donna and Lisa. I really appreciate your experienced advice. I have never done a nest change. I have read, and re-read how to do it on the Sialis site, and will print it up and take it with me in case I forget anything. I am very nervous, since this is my first time. But I do not want to find dead baby Blues. I have not lost a single nestling in the three years I've been doing this, and I sure don't want to start now. Those large larva I found in the TRES nest were absolutely disgusting. I will take care of the nest change this afternoon, and let you know how it goes. Thanks again!

Doing a nest change was not nearly as scary as I thought it would be. Everything went splendidly. I only found one small blow fly larva stuck on one of the babies legs. I just flicked it off. It is my understanding that the small ones are the danger because once they're big and fat at the bottom of the box they are ready to pupate? I'm sure there were others in there as well, as there is never just a single blow fly larva. I think this nest change will be well worth it. The babies were great. They let me go over them (as per Sialis instructions), and then they were one by one placed back in the new, clean nest. Thank you both so much for your advice and encouragement.

Wow, that's impressive! Where did you get the nest? You saved an old one?

I am glad everything went so well Kendra! That is great. I am sure like you said, if you found one larva there were more, just not big yet. The first time I did a nestchange I was shaking like a leaf but it went fine and there were tons (at least 60!) of midsized larva and one remaining baby. Thankfully the one did go on to fledge, never would have made it another night though had I not done the nestchange. I did one last year too (and I wasn't nervous at all) as I found a dead nestling but there wasn't any larva, not sure what happened to that one but shortly after another died too, the other three went on to fledge. I am suspecting bad food but no way to tell for sure.

Donna

Sara, I made a new nest as per instructions on the Sialis website. I have a bag of dried grass that I use to give to my indoor birds (Gouldian Finches) to make nests, so I used that. Thanks Donna! It sounds like with only one baby, those blowfly larva would certainly have killed it quickly had you not acted and changed that nest. Both parents were watching me as I approached the nest. I knew I had to do this, so I spoke with them while I looked at them to try to let them know this was something I was doing to help. Amazingly they watched, and didn't even dive bomb me like they usually do for nest checks. Then to make it up to them, I filled their bowl with mealworms, and they went right back to feeding their nestlings. It was a pretty amazing experience.

OMGosh! I have not experienced blowfly larva. What does it look like? It gives me the "heebie jeebies" to even think about it. How would I know if a nest has the larva without actually picking it up and looking underneath?

When I do a check it's a quick one just to see if the babies are OK (breathing). I only looked twice with my babies that fledged last Saturday. Their nest was very clean with only a meal worm in it. I don't think I could clean out blowflys, so hopefully I won't have to. What brings them to the nesting box? Sorry to be so full of questions!

Mlkbskt, Blowfly larva are disgusting looking little creatures. Google it and you can find images of them. I only used to do nest checks like you, with a quick peek to see the babies are ok until I cleaned out a Bluebird nest last year and found a bunch of full sized blowfly larva underneath it. I was amazed all those babies fledged from that infested nest. I now use the spatula method (have a spatula dedicated to bird houses) and take a peek underneath the nest to see if I can see anything. But if the blowfly larva are small, you probably won't even see them that way. And if they are really large, they are ready to pupate and have already done their damage. A little fly just flies in there and lays her eggs. That is where they come from. There is really nothing you can do to prevent it from happening. It is a really gross job, and I always wear latex gloves to do it. Glad to hear your nest was so clean. My nests haven't been infested with blowfly larva too often. I've read it is more likely if the weather is very wet, which it had been around here.

Just thought you'd all like to know that the nest change was a success. All Five babies fledged this morning, and when I checked the box, it was clean (no blowfly larva at all). The babies are up in the trees behind their box, and are being well fed by the parents who are still coming many times a day to the mealworm feeder. Thanks so much for all your help.

Congrats on the successful fledging!

Donna