Perhaps stress can accelerate egg passage so that a shell doesn't get deposited before the egg is expelled. I'm not a vet, but the timing, & all THREE laying shell-less eggs, right after a couple of stressful events... I'd keep an eye one them, but would be inclined to write it off to stress--this time. (for what it's worth, my pet duck had some sort of metablic disease, possibly even cancer. Her bones were terribly decalcified--had her x-rayed--& the vet was able to humanely euthanize her with an injection. don't want to worry you, just explain the radical & probably completely different problem she had. She was laying soft-shells regularly, which is why I took her in to a vet who treated birds) It's true that various grain fungi--like aspergillosus (sp?) can be deadly to birds--if consumed. That's why the seed in feeders needs to stay DRY & the feeders frequently cleaned. But the effects are pretty severe--staggers, respiration difficulty--& your hens sound fine. As you observed, home laid eggs from hens well-cared for that have access to greens--the shells are like rock! & the yolks are so much deeper colored & tasty.

Sounds like you really have some challenges. You have my sympathies! A tiny poked hole is more likely a house wren's thin sharp beak, sometimes taking them some distance away, or simply tossing them out. The house sparrow will toss the eggs out, but their finch-like beak would not as likely make a tiny poke hole. And the HOSP is more likely to stick around, harass, or even take over the cavity. "Do BB's destroy their own eggs" ... No "the nest possibly could have been flooded?" ... are there leaks that could be fixed? "Are the HOSP really sneaky" ... yes, but HOWR are sneakier ... "and resistant to the Sparrow Spooker?" ... yes, and house wrens will not be deterred by a sparrow spooker. House Wrens are even sneakier, faster and silent, leaving no evidence behind, only destroying eggs or young. You might hear them singing, but might never, ever see them! There are some links to sound files of house wren song and chatter on Bet's web pages, so you can learn to hear the unwelcome sounds of house wrens. Visit Bet's web page for more info. And by the way, the Carolina Wren is a very different bird, welcome almost anywhere; not a threat to other birds. BlueBars Here is a link that might be useful: http://www.sialis.org/index.html

My guess is they are cowbird eggs. Very gently remove the brown speckled eggs (as not to crack the bb eggs) they will hatch before the bluebird eggs do and will eventually take over the nest box and the baby blues probably will not survive. I get them in the poor chipping sparrows nest and the cowbird babies are bigger than the nest. The chipping sparrow eggs are thrown out of the nest by the baby cowbirds. Karen

Karen, What a bad boy!!! But if there's food around, the female should be able to raise the babies despite his behavior, right? I think my first nest of babies was raised largely on suet! I keep the suet and worms in the same feeder, so when the worms are gone they go right to suet. Do you have an alternate food source? And of course the bugs should be pretty plentiful by now too... Good luck Karen! Ann