A cooler cave for bats
As you travel along the rural route 45 in Huntington, Pennsylvania, you may enjoy the farm fields, rolling hillsides and ambling streams that dominate the landscape. It may not be obvious at first, but beneath the surface lies the largest limestone cave system in the state. The caverns, known as Indian Caverns, tunnel and wind down about 100 feet following an underground stream. They may prove critical to protecting endangered bats.
Indian Caverns in central Pennsylvania was once alive with visitors exploring the cave’s Native American artifacts and stunning natural formations. Historical evidence dating back to 8000 B.C.E. suggests the cave was likely used by the Susquehannock, Algonkian, and Iroquois tribes up until the 1700s.
Following its opening in 1929, Indian Caverns stayed within the Wertz family over five generations. Outfitted with electricity, a gift shop, and doors blocking the entrances, the cave was mostly void of bats.
The absence of bats from Indian Caverns turned out to be a good thing. When a deadly fungus swept through bat populations in Pennsylvania starting in 2009, it likely didn’t reach high amounts in this cave. White-nose syndrome is a disease that affects hibernating bats and is caused by a fungus, Pseudogymnoascus destructans, or Pd for short. The Pd fungus attacks and irritates the bats’ skin, causing them to become more active and burn up their winter reserves.
When the attraction closed in 2014, conservationists saw an opportunity to cater to the winged clientele. In 2016, Western Pennsylvania Conservancy acquired the cave and announced that the cave plus 13 surrounding acres would be protected for bat conservation. With support from the Indiana Bat Conservation Fund, Pennsylvania Game Commission, Richard King Mellon Foundation, and the Pennsylvania Fish and Boat Commission, the cave was well underway to becoming an ideal bat sanctuary.
There was only one problem. The air trapped in the cave was too warm.
“We have recently documented that bats that have survived WNS are seeking colder sites to hibernate, as these colder temperatures help them preserve their fat reserves longer and not be exhausted by the disease before winter ends,” Greg Turner, biologist with the Pennsylvania Game Commission, told Western Pennsylvania Conservancy. “The Indiana, tri-colored and little brown bat species are all declining due to this disease, so improving access to and conditions within this cave are critical.”
In an effort to cool the cave down, the airflow needed to improve. With an average ground temperature in Pennsylvania of roughly 52 degrees Fahrenheit, creating better airflow would chill the cave down to a hospitable temperature for hibernating bats, around 34–38 degrees. Biologist opened sealed passageways, demolished the large concrete barrier at the entrance of the cave, and reopened the smaller back entrance last November. This allowed cold winter air to slide down the nearby hillsides, sink down into the cave system, and push out the warm air through natural processes.
Bob Anderson, the assistant field supervisor at the Service’s Pennsylvania Field Office explained that before restoration began, tri-colored and little brown bats visited the cave, despite visitors and limited entrances. “In other mines, caves, and surrounding forests, endangered species of bats have been known to breed, hibernate and roost, so we’re hopeful that more bats will soon recognize this cave as a stable hibernacula and begin populating it.”
In the first winter following the cave door demolition, ten bats of four different species were found hibernating inside. This small increase from the winter before is still a major victory. Given more time, biologists anticipate the return of more bats.
And, bats aren’t the only ones benefiting! The surrounding forest and over 1,200 linear feet of frontage along Spruce Creek, a nationally renowned catch and release trophy trout stream fishery, are open to the public. Anglers from all over are now able to access Spruce Creek for fishing and recreation. Conservation of this area also ensures the important trees and shrubs surrounding the creek remains healthy, conserving the quality of the water and overall ecosystem health.
Click here to learn more about bat conservation and white nose syndrome.
