Well, to update about putting on heat shield prior to eggs. As I mentioned, we left for a few days and the temps were forecast for the mid 90’s, with heat index above 100 degrees. I did put on heat shield (complete nest was built) and when I got home found two blue eggs and hoping for another one this morning (Sunday). But remember, this was for a pair of blues which had just successfully fledged 5 babies from this same box which had spooker, wren guard & heat shield all on, so they were familiar. Not sure I would do this with newbies.