DUH !! Sorry Lisa- I looked it up on the internet. Not too bad for a mentally challenged ex- PE teacher, huh? Seven years ago, I had to have an 8 yr old show me how to turn on a computer at the public library!!

Hey Anita, I thought that too until one day I watched my momma Bluebird go up under the wren guard on the Chickadee nestbox. She was getting a bug on the ground before that and must have seen the hole when she was on the ground. So while it may take a bird longer to find a nestbox with a wren guard I don't think it is fullproof to stop HOSP as they could easily find the hole too if on the ground or by observing another bird going in and out of the nestbox with a wren guard. Just my opinion really but that it how it seems anyway. Donna

Anita, I have a similar situation in that my bluebirds are back for a second brood. The house wrens didn't bother the box during nest building (and the box had been empty for about a month and there were no sticks). Mama laid her 1st egg this morning and this evening, a house wren took out that egg and smashed it at the base of the box. I think that now I'd say "the rule is that there are NO RULES!" I've had house wrens attack several eggs or several chicks, never just one egg. As far as putting up a wren guard, the problem you have is that the house wren has been in the box. And where there is one house wren, there are usually more near by. The reasoning behind the general rule of putting the wren guard on the box when the 1st egg is laid is that the female is less likely to abandon the nest if she can't figure out the wren guard. It's also hard to say whether your female is 'with egg' and I'd hate to see her not be able to get into the box to lay her 1st egg, if that makes any sense. You could wait till it's afternoon and the bluebird hasn't laid an egg and put it on. If she can't figure it out, I'd take it off till the afternoon of the next day, etc. Good luck, Linda in NW GA...

I have no idea when they would be "positively" safe but I'd wait at least 7 to 8 days with bluebirds and 12 to 13 will smaller species like Chickadees or Nuthatches. Linda had a thread here regarding a titmouse baby, 13 to 15 days old, still being harassed by HOWR entering the box. It was a single baby, the HOWR had already gotten rid of the others when they were younger, but the HOWR didn't seem to mind that it was close to fledging age and too large to physically remove. Thankfully that little TITU did fledge safely. In my last nesting of BHNU I left the wren guard on till they were 14 days old.