It's hard to say. They lay one egg a day until the clutch is complete. I don't think the spooker scared her off, it could be that something did happen to her. Let us know is she comes back.

Karen

Have you seen the female around?

You could try the old trick of putting a long piece of straw or grass in the entrance hole, and see if it gets removed. That might at least tell you that some bird has visited. Keep checking to see if any eggs are removed, too, in case there might be a HOSP or HOWR visiting. House Wrens can be very sneaky!
I hope she returns...
BlueBars

I just saw the male on the power line. This could mean one of two things - something happened to the female and he is alone now, or he is waiting for her to lay an egg. I didn't check the box just in case she might be in there. I will look later. How long does it take for a female to lay an egg?

Nope, still only two eggs. Has anyone heard of a bluebird abandoning a nest because of spooker? I feel like next time I will wait for incubation to start.
I was checking my boxes to see if anybody could adopt those eggs. I found only one nest where incubation had not started yet. If this is a sparrow nest, I was thinking about switching the eggs and let them raise bluebirds.

Also, I have starlings building right now, but I think they are too big for it.

Some females skip a day in egg laying. My first female skipped one day in every single clutch. From watching my friends in box cam, it takes her female between 10 and 20 minutes to lay an egg. MOST egg laying is done early morning but my female (same one who skipped) laid eggs twice in the late afternoon, after 4:00. Because I was never sure when she might be laying I never checked her box until I saw her exit the box so that I'd be sure not to spook her in the middle of egg laying.

That's a gross looking nest, what is the black stuff
Keith

But it has been three days already.
Also, can you tell whose nest that is on the picture? I'm not sure if this is a sparrow's or chickadee's (or maybe carolina wren?)

Keith, "black stuff" is moss.

I have never seen a Sparrow's nest. My Dee nests have always been neat with moss, pine straw and a nice soft fir lining with a spot to pull over the eggs like a blanket.

"If this is a sparrow nest, I was thinking about switching the eggs and let them raise bluebirds."
Now THAT would be a hoot! (Watching sparrows raise bluebirds). But it is NOT a good idea. And probably not legal.
Have you tried the long piece of straw or grass in the entrance hole trick yet? Or am I just wasting my time here offering suggestions?
Anyway, if it was my decision, I would wait and see if Mama bluebird returns, or maybe Papa bluebird will attract another female bluebird. But then, I would not be hosting house sparrows.
You do know that by raising starlings and house sparrows, (invasive species) you are endangering the bluebirds? It is not beyond the realm of possibility that could be the reason Mama bluebird is missing.
Bluebars

Bluebars, I know about the "straw of grass" trick, I do my reading :) But I don't think there is a reason for it since she is not laying eggs and not incubating (the eggs are cold).
I don't have any sparrow nests at this time in the yard. Also, the eggs and nest have been intact all this time, even without the spooker.
The nest in this picture is in another yard about 500 feet away, in a wooded area (not the sparrow's favorite) and it don't look like any sparrow's nest that I have ever seen. Also, I have never seen any sparrows there. But I do have an active bluebird nest in that yard with 4 babies. Whatever it is, it hasn't harmed them.
About starlings - she successfully raised her first brood with 4 starling nests just few feet away. I even had a camera in this box. I never saw any starling trying to get in.
I still wonder about this nest - I can't find anything like it even on the nest's ID's page on sialis.com. Maybe the nest is not finished?

The shape of this nest, reminds me of a couple of HOSP nests I've had. I'm not saying that is what it is. I have never heard of a bluebird abandoning a nest because of a spooker. Did you make sure she accepted it right after you put it on? I bet something happened to her.

If the eggs are cold they are probably not viable. I have no idea what that mystery nest is but it looks like "everything but the kitchen sink!" :D

Yes, the shape of this nest is the same as a sparrow's nest, but the nesting material is not common for them. My chickens and geese (and their feathers) are just 300-350 feet from there, and it is hard to believe that a sparrow wouldn't fly there to get his favorite nesting material.

"Did you make sure she accepted it right after you put it on?"

Tamsea, no, I don't think you can check it if she hasn't started incubating yet. She's not suppose to stay in the box at this stage anyway.

"If the eggs are cold they are probably not viable."

Chicken and geese eggs can stay cold for up to one month and still be viable. Small birds probably have a shorter "storage" period, but they should be good for at least a week.

That is one strange looking nest! Have you seen any birds around the nestbox? HOSP nests are domed, they fill up the whole box up to the top even so when they enter they go down into the nest and have nesting material above them. Never saw moss in a HOSP nest before but you never know.

Hopefully you didn't loose the momma Blue, strange no more eggs. I have never had problems with them not accepting a spooker even at the park where I monitor houses I put them up last year without a problem and I couldn't make sure thay they accepted them there. I put one up on the nestbox in the yard on Saturday and the pair had no problem with it whatsoever. I added a wren guard today that is making me uneasy as I cannot tell if they accepted it or not and I am not sure what to do as she is in the middle of egg laying now. Three eggs down, not sure how many to go.

Donna

I've never heard or read that bluebird (or any songbird) eggs can stay cold for a week and hatch. That is a new one for me.

Today I found an egg in that nest! It's 2cm long (20.5 mm). According to http://www.sialis.org/eggsizes.htm it could be a Carolina wren or House sparrow. It's larger than the wren and smaller than the sparrow. While investigating, a carolina wren was screaming at me from a near by bush, and it seemed to be very upset with me for being there. It may be his nest or he could have a nest near by.

I can't stay on that yard for long to make sure they accepted it because have small baby with me right now. Do you think this is a good idea or I should take it down? This is the box

Janie - birds lay one egg in day, and same, as you wrote it earlier, skip a day in egg laying. She starting incubation only after she will lay her last egg. All this time eggs stay cold - up to 10 days if she skipping days and lay 5 egg. I surprised that this is new for you.

I think your spooker looks fine! I doubt it would scare them off. I have never had Blues scared of the spooker, now the wren guard is a different story but they have always tolerated the spooker.

Hopefully that is a Carolina wren nest you have there. Cute baby blues in the box!!

Donna

Today I saw a male and female (probably new one)singing near the box and going in and out of the box, so I removed the old eggs.

Now about "strange" nest. I installed a camera in this nest. This is what I found out. The Carolina wren are building a nest there now, but the eggs are not hers. The next day I found an egg under the nesting material, and then found another. I think a different bird laid it previously and then abandoned it for some reason. Now the wren are trying to cover it. Here is link to camera http://www.mycampage.com/starlinka
I turn it off from about 11PM to 6 PM because it is extremely hot here and the camera and box over heats.

My understanding was that a complete clutch was sitting, cold, for 5 days. Five days AFTER the last egg was laid. That was what I understood and was commenting about. Of course I know that incubation doesn't start till the last or next to last egg is laid.

It's not а complete clutch, just 2 eggs. It was in my first post. It's been five days since the last egg was laid, 7 days all together. Some bluebirds have 7 eggs in their clutch so 7 days of being cold is not a problem.
Bellow is the link about egg storage.

Here is a link that might be useful: Egg Storing