I put up a couple of wren houses last summer, two different ways: one I did hang on a too-thin branch, and it did fall down this fall! The other I put up on a pole away from most activity, and wrens did make a nest in there and we enjoyed watching them go back and forth (Carolina wrens). One of these houses did come with a small piece of wood for mounting the house on a tree - it was screwed into the back of the house, with some showing above the roof. Then you would screw the upper part into the tree. I don't know about advice as to the placement of a house in a tree, though. Good luck -

Thanks for the replies - so far the House Wren has not touched the surviving two Baby Blues - and momma and Papa are taking care of them. However - I can hear the Wrens all around, and I also am removing sticks from the other boxes around the property. I should have tried a Wren guard - however I have never put one on - so was worried about the Blues not taking too it. But if they nest again, I will for sure try it - after the first egg is laid. One a side note - we have a dead tree in our back yard - that a wood pecker bored a hole in, and must now have a nest in it. I saw her chasing the wren a way - but her nest is pretty high up. Also - we have a Phoebe nesting under our overhang - this is her second year. I went and checked her eggs out - and there was a Cowbird egg in it! We also had two robins nest near our house - both nests were robbed of their eggs - I'm thinking the crows got at them. Unfortunately no Chickadee nests in our boxes this year.. but probably best because of the Wrens..... seems like they arrived early this year. So did the humming birds.

House wrens are only a threat to Bluebird eggs and new hatchlings until they are about 6 days old, after that the wren can no longer pick them up and throw them from the nest which is what a wren will do to baby birds. If you had almost fully grown babies killed in the nest it was probably due to House Sparrows, the wren maybe came afterwards and filled the house with sticks. If you have wrens in the area once the Bluebird lays the first egg you can install a wren guard, but you would need to watch closely to make sure the Blues accept it, some don't. A wren guard is made of cardboard and comes down off the front of the nestbox and down to conceal the hole of the box from the frontal view, sides can be added to prevent a wren on the top of the nestbox looking down over and stills seeing the hole. Info on this is on the sialis.org site. Also to prevent House Sparrow attacks you can add a sparrow spooker to the nestbox once the first egg is laid, it is to be taken down right after fledging. This info is also on the sialis site. Good luck! Donna

Unless someone else has more ideas, here's my plan. I'm going to move the current empty egg nest and pole away from trees, about 15' aways. I'll equip it with hole guard, wren guard, and preditor guards.. hopefully the move will be accepted by the birds. As soon as I can, I'll erect another house as far away from the trees as possible. If the wren has ruined this nesting there will be another spot to nest. Without trees near by my biggest concern then will be heat. I may remodel the house with heat guards. If this all fails, I may just give up on expecting 2nd broods here. To tell you the truth, I'm a bit discouraged and frustrated.. how in the heck do these birds ever reproduce!!