There are 5 boxes mounted on the 30 foot utility pole. The cross arms are offset so the bats can exit out of the top houses without running into the lower boxes.
The lower 4 boxes have back crevice/access slots.
The lowest 2 boxes are mounted onto a surface of vertical rough sawn boards gapped about 5/8" between. There is another horizontal board in back which creates a channel through which the bats can move between these 2 boxes at anytime hidden from view.....
This year, 2011, the middle left box has had the most usage of these 5 boxes.......it is 3 crevices with rough sawn one inch boards. It is covered with black felt paper. I am noticing more and more that both species, little and big browns are preferring boxes covered with felt paper and sometimes aluminum........I think the extra layer provides greater heat retention through the night........
The largest box in the middle left is one of the few pole mounted boxes used by my big brown maternity colony......
