Improving the suitability of artificial roosts as a management tool for imperiled bat species
Artificial roost structures are promoted to supplement or compensate for roost loss, providing critical summer reproductive habitat for bats. My research explores two aspects of management concerns for bat boxes: providing suitable microclimates for reproductive females and increasing the likelihood that bats find and uptake newly installed roosts. First, I compared the microclimate profiles between standard rocket box designs and two modified versions: a box insulated by an external water jacket, and an elongated box with an attic space inaccessible to bats. I found that the insulated design buffered hot temperatures during the day, reduced overheating events, and retained warm temperatures throughout the night compared to the reference and attic designs. These results indicate that insulation is important to consider for box recommendations. Second, I tested the use of social call playbacks as lures for increasing site activity and uptake of bat boxes. Multiple bat species readily used the boxes and while lure use increased bat counts in boxes early in the season, the effect was marginal and did not occur later in the season. Lure use also positively increased the activity of the focal species, little brown bats (Myotis lucifugus). These results suggest lures show promise for helping bats find novel roosts, but more work is needed to improve this methodology.