Bluebirders routinely trap House Sparrows because they are competitors for nest boxes, and the sparrows will kill the chicks and even adult Bluebirds occasionally. I had Bluebirds nesting in a snag in my back yard for 2 years (the snag blew over last fall), and trapped several House sparrows using an inbox trap. There is a lot of good info on trapping House Sparrows at the link below. Here is a link that might be useful: Managing House sparrows on Sialis.org

Hi, Maifleur. Very interesting article. Thanks. And I do think they are getting smaller. I bought 2 Blue Tits nest boxes and after they started to build a nest, the Tree Sparrows (for sure) put them out and are now nesting in there. They REALLY SQUEEZE them selfs into the tiny, tiny role!!! We are talking about Tree Sparrows into very small roles!!! The solution was to take one of the boxes and nail a piece of wood with a smaller role in front of the original role, almost too tight even to the Tits and now they are happy and nesting in it. But I'm paying a lot of attention to the House Sparrows (no signs so far), and had seen the www.sialis.org thanks to someone who put this information at another topic. SO SAD!!!! We learn so much in this forum!!! Thank you all that have inspired me !!! Agi

Gibby, house wrens and house sparrows are entirely different species. House sparrows are a non-native bird and are considered pests by many, thus are not protected by law. House wrens are native birds and it is illegal to tamper with their nests. I do not allow house wrens to nest in my boxes, however, because as you said they are can cause harm to the eggs and hatchlings of other cavity nesters. I remove any sticks I find in my nestboxes and, fortunately, have not come upon a completed house wren nest (or else I'd have to leave it alone). Since I monitor my nestboxes twice each week during nesting season I can usually catch early nesting attempts by wrens and stop them. You can find out more about both species at this link: www.sialis.org Kathy

It seems really unusual that there would be House Wrens in southern Georgia during the summer. They are supposed to be winter residents there. The punctured eggs however lead me to think that it would have to be a HOWR. It is also weird that there were only two eggs punctured and they were all still in the box at first: from my own experience with HOWR attacks, they puncture ALL the eggs and drop them right outside the box. It may have been a HOWR that did everything, or it could have been a HOWR that punctured the eggs, and then something else may have eaten the eggs. According to a birding book that I own, House Wrens are "common in open woodlands, shrubs, farmlands, suburbs, gardens, and parks." It's really hard to pinpoint exactly what happened here. Make sure they get a predator baffle and a sparrow spooker on their box for the next time the Blues lay eggs. Wren guards are often ineffective after an attack has already occurred on a box. If you are going to put up a wren guard, I would suggest either relocating the house by atleast 100 feet, or rotating the box 90 degrees. There is a very simple design for a wren guard using the corner of a Cheese-It box which can be put up and taken off very quickly. Usually when one of our boxes gets attacked by HOWR, we never see or hear them... one minute the eggs are there, the next they are gone. They are very sneaky. Good luck. Ken