Researchers converged on Grandfather Mountain this week to venture to the area’s caves in search of Virginia Big-Eared Bats. The bat, with its characteristic large ears, is on the state and federal endangered species lists.
Bat counts were conducted at Cranberry Iron Mine and at Grandfather’s Black Rock Cave and Mystery Hole Cave. These three locations, all found in Avery County, are the main spots that the Virginia Big-Eared Bat is found in North Carolina.
Counts are conducted every two years and are scheduled during the winter, when the bats are hibernating. This year researchers from Grandfather Mountain, the North Carolina Wildlife Resources Commission and the National Park Service attended the outing.
The trip to Cranberry Mine occurred days before the Grandfather expedition. The mine has many levels, but just one level was explored with a total of approximately 200 bats counted. None of those were Virginia Big-Eared Bats, but species identified did include Big Browns, Little Browns and Northern Long-Eared Bats.
At the Black Rock Cave located on Grandfather Mountain, approximately 230 Virginia Big-Eared Bats were counted, down from the 2007 count of 376 bats. The count at Mystery Hole also decreased. Five Big-Ears were recorded this year, down from 55 in 2007.
Grandfather Mountain Naturalist Jesse Pope said that this decrease would not spur any immediate concerns.
“The cause could be natural, the caves could be getting too cold,” said Pope. “There is lots of speculation as to why the numbers might have gone down but we really don’t know. It’s normal for the numbers to fluctuate occasionally.”
Pope also took water and dirt samples from the Mystery Hole to be tested for invertebrates. Much is still unknown about the Mystery Hole and its inhabitants. The cave was originally discovered in the 1980s by Cato Hollar, who has mapped all of North Carolina’s caves for the Department of Environment and Natural Resources. The cave’s location was then lost for over 25 years until being rediscovered by Hollar in 2007.
Only the experienced caver with technical training can attempt entry by rappelling down a narrow hole for 40 feet. Once inside, the cave stretches for 300 feet.
Numerous gates have been placed at each cave entrance to keep curious visitors out. Pope stressed the importance of staying away from caves in the winter.
“Continued disturbances will cause the animal to leave and never return to the site,” said Pope. In the winter time, this extra flying around causes the bat to burn its fat stores and without food it could eventually die. In order to have the least impact, the scientists venturing into these caves to conduct counts limit their time to keep the cave temperature from significantly rising.
Pope also noted the White-Nose Syndrome, which has killed tens of thousands of bats in the northeast this winter, as another reason for people to stay out of caves.
Bats with the syndrome have a white fungus on their muzzles and other parts of their bodies. The affected dead and dying bats are usually emaciated and those found outside are severely dehydrated.
Biologists are not sure if bats are transmitting the syndrome, if people are the cause, if both are spreading it or if it comes from an entirely different source. National and regional caving organizations are working with biologists in the northeast to help assess the situation, provide advisories to the caving community and document cave visitations to determine if cavers could be spreading the cause of the outbreak.
“This fungus hasn’t been found in this part of the country,” said Pope. “And of course we hope to keep it that way since bats are such an important part of our ecosystem and we have such special species on Grandfather.”
For more information on the Grandfather Mountain Naturalists and their efforts to protect and study endangered species please visit www.grandfather.com or call 828-733-4326.
