Mammoth Cave National Park Detects White-Nose Syndrome Among Its Bat Colonies

This Long-Eared bat, taken from Long Cave in Mammoth Cave National Park, earlier this month tested positive for white-nose syndrome. NPS photo.

Mammoth Cave National Park officials announced today that they've confirmed white-nose syndrome, a deadly disease to bats, among one of the bats that hibernate in the park.

"On January 4, our National Park Service biologists discovered a Northern Long-Eared bat at Long Cave. That cave is located within the boundaries of Mammoth Cave National Park, and the bat showed symptoms of white-nose syndrome," said Sarah Craighead, the park superintendent, during a conference call with reporters. "I am incredibly sad to report that we have confirmed that the bat was infected with white-nose syndrome. ... This is the first bat that we have found inside the boundaries of the park that has been infected."

White-nose syndrome was first detected in New York state in 2006 and has since killed more than 5.7 million cave-hibernating bats in eastern North America, according to the U.S. Fish and Wildlife Service. Mortality rates of bats have reached almost 100 percent in multi-year infected caves, according to the agency. So far, at least 19 states and four Canadian provinces have detected bats with the disease, which has been found in 21 states overall.

While the disease was detected elsewhere in Kentucky early in 2011, it hadn't previously been detected within Mammoth Cave National Park's hibernacula -- winter bat roosts -- until this case arose.

There are more than 400 caves in the national park and the staff has been testing for the fungal disease since 2009. Access to all caves, including the iconic 390-mile-long Mammoth Cave, is controlled by the Park Service and limited to guided tours and research projects.

Each winter about 25,000 bats hibernate in the park, and officials know that at least 26 of the 400 or so caves are used for roosting. Fourteen of the caves are only used as summer roosts, six are used for winter roosts, and six are used both for summer and winter roosts, park officials say.

Concerned that the disease could sweep through the park's caves, officials in the fall of 2010 established protocols for visitors to follow with hopes they would prevent human transmission of the fungus that causes the disease.

While it's not considered a health threat to humans, white-nose syndrome is deadly to bats, and there are fears that entire species could be eradicated by it. As the disease spreads, its impacts could ripple through ecosystems. Not only are bats efficient predators when it comes to insect control -- some bats can eat up to 2,000 mosquito-sized insects in a single night -- but they in turn are prey for hawks, owls, and skunks, just to name some predators.

"The bat was not found within Mammoth Cave itself," Superintendent Craighead stressed. "Long Cave is a separate cave, it is not connected to Mammoth Cave, and we do not allow visitors to enter Long Cave."

While Long Cave is roughly 5 miles away from Mammoth Cave's Historic Entrance, that distance is not significant for a bat, said Dr. Rick Tooomey, the director of the Mammoth Cave International Center for Science and Learning.

"We don't see many bats along the Historic Tour route, but if white-nose goes the same way as it does in other parts of the country, many of the caves show infection, both the larger roosts and smaller roosts like the Historic section," he said. "So we might expect to see a few infected Tri-colored bats, the most common type that we see along the Historic tour."

So far, however, there has been no evidence of bats traveling between Long Cave and Mammoth Cave, said Steven Thomas, the monitoring program leader for the National Park Service's Cumberland Piedmont Network.

Long-eared bats, he added, are only occasionally seen in Mammoth Cave, while large numbers congregate in Long Cave.

Mammoth Cave is the ninth national park to have white-nose syndrome confirmed within park boundaries. Previously the disease has been found among bats from parks such as Great Smoky Mountains, Acadia, and New River Gorge National River.

The presence of the disease will not lead to a closure of Mammoth Cave to visitors, said the park superintendent. Tours will continue with visitors -- about 400,000 a year tour the cave -- having to go through the decontamination process that was implemented in 2010, she said.

There are nine species of cave-dwelling bats in the park, and four species of tree-dwelling bats. "All nine are at risk from white-nose syndrome," said Superintendent Craighead. "So far, tree-dwelling bats do not seem to be as susceptible to the disease."

Researchers will continue monitoring the park's caves in the months ahead for white-nose syndrome.

"We are checking all of those caves," said Dr. Toomey. "So far we have not found any other cave at the park showing white-nose. We're also working with the state in checking other caves in the area. This month and February is the normal time for us to do counts of caves with endangered bats, particularly grey bats and Indiana bats, we will be doing those counts. ... While we're doing those counts we'll be watching for additional bats that might show evidence" of bats that are infected.

"Given what we've seen in other places, it will not surprise us to see additional bats and additional sites (that are infected), if not this year then in the coming winter or the winter following. That tends to be the pattern," continued Dr. Toomey. "You find it in a few places at first and then it becomes more and more prevalent."