These ideas for mounting a Peterson box are from Al Drollett of Al's Peterson Style Nestboxes.Peterson boxes are attractive to bluebirds, but are top heavy, and thus must be mounted securely so they remain level. If the box tips forward and the door is opened all the way too quickly during monitoring, eggs or babies could easily tumble out.
Using an EMS strap/clamp to hold the top of the box to a pole really helps.
Drollett recommends using two "U" bolts on the bottom to firmly hold the box on the conduit (only one shown in my photo), plus the clamp on the top to stabilize the the whole assembly. This set up adds to the strength to the mounting and should prevent shifting of the box on the conduit. Another solution is to slowly open the door only part-way whem monitoring.
