Figure 2
From: Big brown bats are challenged by acoustically-guided flights through a circular tunnel of hoops
Example effects of mine blocking on bat roost activity. Counts of bats entering or exiting through several different entry points in two abandoned mines show reduced activity at entrances provided with corrugated metal culvert pipes as a component of closure to human access. (a) At Blind Springs Hill mine, subsequent to disturbance due to gating and permanent presence of corrugated pipe, bats ceased using the upper entrance (#4). Bat activity shifted to entrance #1, with the angle-iron gate. (b) At Tungsten Hills mine, gating and corrugated culvert installation of entrance #1was followed by a drop in bat activity overall and cessation of nearly all activity flying through the corrugated culvert pipe.
