Well, there seems to be something to the extra room/floor space in the box. That is one part I didn’t quite understand. Now I think I understand that the box is designed much larger because this allows the larger bluebird to have more room to move, fend off and escape to fight outside. If you look at a fight outside in the open, bluebirds tend to have an easy time fighting the sparrows off. I tried two holes in a small box and it failed because the bluebird is still trapped in a small floor space. They cannot open their wings fully but the sparrow can move around freely since they are so much smaller and quick. I am thinking of making mansions this time around because I cannot monitor my boxes at all times.
