"FARMINGTON, PENNSYLVANIA—In a chamber a few hundred feet underground known as the Stomach, long-time cave guide Lisa Hall is talking about bats. Less than a decade ago, this cave system was home to thousands of them—little brown bats, northern long-eared bats, Indiana bats, and big brown bats. Today, she says, when the staff spot a single individual (almost always a big brown bat, Eptesicus fuscus), they get excited.
This situation is not unique to Laurel Caverns, the enormous cave system sixty miles south of Pittsburgh that I toured with a group of journalists in early October. (In addition to the Stomach, Laurel is home to the Flue, the Dining Room, and the Panini Press.) White-nose syndrome, the fungal scourge that first arrived in Howe Caverns in New York in the winter of 2006-2007, has killed off an astonishing number of bats around the Northeast and elsewhere.
Winter refuges like caves—ecologists call them hibernacula—have seen devastating decreases to bat populations that sometimes numbered up to 100,000 individuals. Greg Turner, a biologist at the Pennsylvania Game Commission, offered up some examples: One site, the Canoe Creek Mine near Altoona, had over 30,000 bats as of a 2007 hibernation survey. Two years later, it had 155. Another site went from that 30,000-bat level down to six individuals in little more than a year. Across Pennsylvania, the total decline in bats may be over 99 percent since the pre-white-nose era. "