The new and improved house (Texas Bluebird Society TB1-C with heat shields). Roof heat shield is 3/4" cedar and the west facing shield is made of 1/8" plastic painted with several coats of exterior white latex paint to eliminate the opaque quality of the plastic.
I also purchased a mister for those really hot Texas summer days.
Working on a spooker to put up today.
*****Update*****
I was too late with the spooked. When I went out to make sure everything was the right size I found an egg outside of the box with the < > beak mark or the house sparrow. When I looked inside I found this.
I am so frustrated. I am also wondering if it was the heat that killed the previous 4 babies or if it was a house sparrow attack that didn't leave any signs on the 2 day old baby birds. Note to self, put up sparrow spooker as soon as that first egg is laid.