Relationship of Orientation on Internal Temperature of Artificial Bat Roosts, Southwestern Montana

Abstract

This study experimentally investigated if bat houses, built using a basic design, would provide suitable temperatures for roosting bats in southwestern Montana. Specifically, we looked at the effects of orientation (east vs. south) on the internal roost temperature, which was then compared to published data on the physiological temperature required for bat maternity roosting sites. We observed no use of the artificial roosting sites. There was a trend for southern-oriented bat houses to have slightly higher daily temperatures and slightly higher maximum temperatures. We determined that the internal temperature of the roosts did not remain in the optimum range for maternity roosts during most days and months. Most temperature readings were well below the minimum value. Bat houses built using a basic design do not appear to provide suitable temperature requirements for reproductive female bats in southwestern Montana. The information gathered by this study will allow us to continue to develop recommendations for design and placement of bat houses in southwestern Montana.