May 18, 2019 at 12:36 am #7230
My next door neighbors have a box that has previously been used by bluebirds. Last year a wren found and used it. This week I discovered bluebirds have claimed it again and there are 3 eggs already laid. I am fearful there is not much I can do to save them from the house wrens. From what I read even the wren guard may not be helpful if a box has already been used by wrens. I’ve never made a wren guard, but am wondering if I should try. Or am I just going to make it worse for the poor bluebirds? Is this a doomed nest?
Willamette Valley, OregonMay 18, 2019 at 9:56 am #7231Carol – Mid-Mo.Participant
If your neighbors agree, I would sure go ahead and put on a wren guard IMMEDIATELY. The wrens from previous year may not be around (hopefully) and any new ones could not see the hole. It’s definitely worth a try I think. I have had more damage from wrens (from a couple extra boxes which I was not aware had BB eggs in them) than from HOSP. One year they threw out my BB eggs on the ground and one cracked egg I could actually see the baby bird fetus – that was not nice! But in 11 years I guess that’s not too bad. Go for it, Cari!May 18, 2019 at 9:58 am #7232David in Stafford,VAParticipant
Yes you should try. The guard is not hard to make. There are directions in the “stickies” on the Forum Index page. I made mine out of a cereal box and covered it with duct tape. Works fine even in wet weather. Easy to remake if it starts to get soggy and seems to keep the wrens away. It will at least give the BBs a chance. If the wrens have not been in the box this season the guard should deter them. Good luck
Stafford, VAMay 18, 2019 at 12:21 pm #7233
Thank you for the encouragement. Think I’ll make one out of a brown shoebox I found. Has anyone experienced bluebirds rejecting the nest with a guard? This BB information website was not very encouraging if it is a box previously used by wrens.
Willamette Valley, OregonMay 19, 2019 at 8:54 pm #7244dogsandbirdsModerator
Cari, I have NEVER had birds totally reject a nest with eggs when I put a guard on a box. Some birds do take a little longer than others but none have ever abandoned eggs. Go for it!
Atlanta, GAMay 27, 2019 at 9:50 pm #7328
I tried putting up a temporary cardboard one right away, but wouldn’t you know it, we had a thunderstorm. Before the storm, I thought the BB were beginning to accept the guard, but I was wary because with 5 eggs in it already, it was hard to know if she had begun incubating.
Well, after the storm, the remnants of the guard had to be removed and I also checked the nest. I could hardly believe my eyes: I could only see 4 eggs; one was missing. So then I was really worried. I decided that if a wren moved the egg, then it was not helpful to have the guard since the wren was already taking over. And if the bluebirds were upset and moved the egg, that was not good either.
So I decided to take it all down and let nature take over. Right now it appears that Mama is incubating and I’ve heard no wrens recently. Maybe the wrens are not returning at all or if the BB are lucky maybe they are far enough ahead of the wren schedule that they will have a successful clutch.
I have not looked inside the nest since the day one egg was missing, about a week ago. Mama BB should be about half way through incubation and if we have some warm weather tomorrow I may check the nest and see if the missing egg is back. I have wondered if it was in the nest hidden somehow, but the nest is small and it doesn’t seem likely. But has anyone heard of bluebirds removing eggs when upset?
Willamette Valley, OregonMay 28, 2019 at 8:54 am #7330Carol – Mid-Mo.Participant
Cari, I believe they will remove an egg sometimes if they deem it to be non-fertile. I had one egg this year not hatch, but it ended up deep inside the nest and when the others fledged and I cleaned out the box I could see the remains of it. Hopefully yours will be lucky and make it out.
P.S. I know the cardboard guards are helpful in a pinch, but I find in the long run it is best to have a lightweight wooden one ready and on hand – they last for years. We made ours and I have 3 on hand in case I need it for different boxes.May 29, 2019 at 8:59 pm #7337dogsandbirdsModerator
Cari, I have NEVER heard of a bird removing an egg during incubation. Let’s hope it was hidden somehow. Rarely they remove an egg that doesn’t hatch and most of the time they leave it where it is.
I totally get worrying about wrens. I have a pair I am still keeping occupied by using various tactics.
Carol’s idea about wooden guards is a really good one. Some people even leave them permanently mounted on the roof and flip them down when needed.
Atlanta, GAJune 11, 2019 at 9:44 pm #7435
Update: Only 4 hatched and I still have no idea what happened to the fifth egg. I figured incubation time starting at the time it would if the 5th egg was still there, and the timing appeared to accurate with their hatching. But only 4 nestlings hatched.
After the egg disappearance I decided to hope the wrens that used the box last year decided to go elsewhere and leave the rest to nature, and with the nestlings now 9 days old it looks like maybe the bluebirds will win.
I may never know why an egg disappeared, but whatever the case I am thankful that at least for now 4 nestlings appear to be thriving.
Willamette Valley, OregonJune 12, 2019 at 3:09 pm #7437SassyParticipant
Hi Cari: I also had an egg disappear but it was after they hatched. I saw it in the nest and a few days after the others hatched I thought I would remove it and I could not see it, so I took the nest out and lifted the babies but it was gone, so I assume one of the parents removed it. The other four did fine and have now fledged.
ConnieJune 13, 2019 at 12:40 pm #7438
This is not the only time I’ve seen an egg disappear, but the timing on this was unusual since she had likely not yet begun to incubate the eggs. It was like the day the fifth one appeared, one disappeared. But whatever happened, 4 nestlings seem to be thriving and so far I have not seen the wrens from last year. Maybe they did not survive the winter or perhaps they found a better place to nest. Just hope we do not see them again.
Willamette Valley, Oregon
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