| Abandoned mines have assumed increased importance as surrogate roosting sites for bats. However, increasing concerns for human safety have led to accelerated programs for mine closure. In efforts to protect roosting sites, "bat compatible" gates are installed on mines showing significant bat use. I evaluated the effects of gating on bat activity at maternity colonies in two previously gated mines and two ungated mines. I also monitored four gated and three treatment mines to determine the potential effects of reclamation on internal microclimates. Overall circling activity increased ≥ 6-fold at the portals of treatment mines post-gating. Generally, gated mines with multiple openings experienced greater changes in ranges between minima and maxima in temperature and vapor pressure deficits than those with single openings. Additional studies of bat compatible gates are needed to elucidate possible long-term effects of these structures on Townsend's big-eared bats. |
