Why did she think feathers in the nest meant eggs were hatching? Bluebird eggs hatch around day 12-14 from start of incubation and they don't have feathers at first, they grow in as the chick matures. Bluebirds don't typically put feathers in their nests, however once in awhile they have one or two in there. This is my sixth year with Bluebirds and only once have I had a Bluebird put a feather in the nest and it was during nestbuilding. Tree Swallows however always put in lots of feathers in their nests. A missing egg could mean HOWR (House Wren)got to the nest as there are tons of HOWR around Marshfield. Or it could mean a HOSP (House Sparrow) got in the nest also. Does the box have a wren guard or sparrow spooker on it? Normally in a failed nesting the Blues will leave and neither they nor a new pair that would come would use an old nest, they would build a new nest on top of it and lay the eggs. If a HOWR or HOSP got one egg and the other three are fine they may continue with incubation however chances are it could happen again. If the adults are around I would leave the eggs alone and just keep monitoring. See if she can recall when she saw four eggs in the nest to give a better timeline of when they should hatch. If she doesn't have a sparrow spooker I would get one up asap. Check out sialis.org for loads of helpful info on properly offering nestboxes to bluebirds, they have instructions for sparrow spookers.

Donna

Since you know how old your bluebirds are, I assume she also has an idea how old hers should be? You didn't really give a timetable here. How long were the first eggs in there? Did she estimate that hatch date? It just seems odd because Bluebirds do not lay immediately after their young fledge. They would also have built a new nest over the old if they were going to reuse that box. If she has the timing down for the day they should have hatched, fledged, etc., then my guess would be those are the old eggs and they never hatched, or something destroyed/took the other eggs and they are re-nesting. If there had been babies in there, the nest should be a flattened mess. Everything Donna said is important. Make sure to have a sparrow spooker up, and check out sialis.org for the information on properly setting up a safe box, time tables (if you need them), etc. As Donna said, you should leave the eggs alone, but you may need to do things (like a wobbling stovepipe baffle) to protect them this time around.

OK So I described her story incorrectly. She didn't actually see feathers, but fuzz around the time the babies should have been hatching. She knows one baby hatched, and expected the rest would too. However, she didn't look again until a couple of days ago, and the 1 that must have hatched is gone (fledged). She is wondering if the other 3 eggs just didn't hatch. She is also wondering if they spooked the mama when they were putting up the stovepipe baffle and the sparrow spooker and caused the eggs not to hatch. They didn't get the baffle and spooker up until after all the eggs were laid.

So, do you think they are the eggs from her initial nest? And, if so, why would the mama and papa keep returning to the nest? I know we will never really know, but I guess her main question is how long to leave the eggs and nest alone? Or should she remove them?

First putting up a spooker and a baffle would not scare away the Bluebirds, good to hear she had those on the box. Secondly what date did she first see the one baby hatched and what date did she look again? Bluebird babies typically fledge 16-19 days after hatching. It is important to keep track of dates to prevent opening the box after the nestlings are 13 days old to prevent premature fledging. You should never open the box after day 13, just observe from afar to know when they are fledging.

Unless she knows how long inbetween her first check and second check I can't really tell you what to do with the nest/eggs that are left. If the adults are still there, I would just keep checking the box to see if anything happens like the eggs hatching or a new nest being built on top of the old nest. "If" one baby hatched and fledged the female blue would no longer incubate the remaining eggs. If she wanted to start a second nesting she would build a nest over the top of the old one. So it is confusing why they are still there. It is possible that something happened to the one that hatched and the other eggs are still be incubated.

Important things to remember and keep track of when monitoring Bluebirds....

* Incubation starts the day the last egg is laid
* Hatching typically takes place on days 12-14 however can be longer at times due to delayed start of incubation during cold spells.
* Nestlings usually fledge somewhere between day 16 and day 19.
* Never open a nestbox up after day 13 (from hatching) due to possible premature fledging which can put the babies in danger as they cannot fly well if their feathers aren't long enough
* Once you know the babies have fledged...take out the nest and clean the box so it will be ready for the next nesting. In Wisconsin Bluebirds typically have two nestings per summer.

Good luck!

Donna

Thanks Donna. I do know all of that information about when not to open the box etc. I do personally read Sialis.com often.

Here's an update from my friend. She said when she looked on May 30, she knows that at least one baby had hatched. She didn't check again until June 14 and the one was gone and there were three remaining eggs. She said two of the eggs are up out of the "hollow" of the nest cup even. Yet, the parent bluebirds seem happy and keep going in and out of the nesting box. Baffling?

She wondered if because they bothered the mama while she was incubating(when they were installing the baffle and spooker), it may have caused the eggs not to hatch?????

That is quite baffling. That would be 15 days from hatching that the baby was gone which is very possible with only one hatchling. I had a sole survior once after a blowfly infestation and she fledged on day 15 and could fly fine. However "if" that one fledged the adults would be with the fledgling right now and not the nestbox. The female can and does start a second nesting quickly but the male would be attending to the fledgling and the female would be building a new nest. To me it sounds like something may have gotten the one that hatched...I would think wren. The eggs that are pushed up out of the nestcup for sure would not be being incubated and are probably not viable anymore. I wonder if they could have been poked by a wren, the female would not incubate them if they were. Your friend could take one out and look at it to see if there are any peck marks in it, wouldn't do any harm cause if isn't in the nestcup it isn't being incubated anyway. If there is one egg in the nestcup that was still ok, it is possible the mom is still trying to incubate it but it probably isn't viable anymore either. I doubt these are new eggs from a new pair or the same pair as a new nest would have been built. From what I have read about the female incubating dud eggs is to leave them until they decide themselves that it isn't going to hatch. Removing the nest/egg can make them move on somewhere else.

Tell your friend she would not have messed anything up by adding the spooker or the baffle during incubation. It doesn't take that long to add those things and the mom doesn't sit on the nest all day long anyway, they actually leave quite often so that would not have caused the eggs to not hatch. I am still thinking wren myself. Has she looked again to see if anything has changed?? I would be interested to know.

Donna