Hey everyone…thanks for the great info!!! Most appreciated! So here’s some more details regarding my situation. Trapping is not an option unfortunately due to time and effort (although my husband on occasion will monitor the situation with a bb gun but despite his good shot, no luck yet). I’m wondering if the depth of the box is what may be allowing those pesty birds to gain access. The dimensions from top to bottom of the box are 8 inches tall (front) x 9.25 inches tall (back), and the hole size diameter is 1 1/16 which is actually smaller that what most plans call for. No perch. Here’s a pic annotated with top and bottom measurements as show by yellow highlighted lines.
