From Staff and Georgia Department of Natural Resources Reports

The disease that has killed millions of bats in the eastern U.S. has now spread to caves in Dade County’s Cloudland Canyon State Park, the Georgia Department of Natural Resources confirmed in a Tuesday press release.

A National Park Service biologist and volunteers discovered about 15 tri-colored bats with visible white-nose symptoms in a Lookout Mountain Cave at Chickamauga and Chattanooga National Military Park in late February, DNR announced, and on March 5, a group led by a Georgia DNR biologist also found tri-colored bats with visible symptoms in Sittons Cave at Cloudland Canyon.

A bat from each northwest Georgia site was sent to the Southeastern Cooperative Wildlife Disease Study in Athens, and histopathology confirmed both bats had white-nose syndrome.

At press time on Tuesday, Cloudland Canyon State Park reported it had received no information yet as to whether the bad news would mean closure for Siddons, a popular cave for guided tours during the warm months. The cave is in any case currently closed until April 1 to avoid disturbing normal bat hibernation.     

White-Nose Syndrome takes its name from the white fungus, Geomyces destructans, found on the muzzles, ears and wings of infected bats. White-nose, or WNS, spreads mainly through bat-to-bat contact, and there is no evidence it infects humans or other animals. But researchers in any case routinely disinfect their clothing and gear lest they carry spores from cave to cave.

The disease was first detected in New York state in 2006 and has since spread steadily to 22 states and five Canadian provinces, killing as many as 6.7 million bats and threatening endangered species such as Indiana and gray bats. In some caves and mines, 90 to 100 percent of the bats have died.

In winter 2012, as reported then by the Sentinel, researchers at Siddons found the bats there healthy. Last year, though, the disease was found in north Alabama and on the Tennessee side of Chickamauga and Chattanooga National Military Park in Hamilton County, and on Monday authorities in South Carolina announced that WNS had been confirmed there.

“We’ve been expecting the discovery of WNS in Georgia after it was confirmed in Tennessee and Alabama counties last season,” said Trina Morris, DNR wildlife biologist. “Still, I don’t think anyone can prepare themselves to see it for the first time.”

To address the threat of WNS, Georgia DNR’s Wildlife Resources Division has been conducting surveys to better assess bat populations while limiting scientific activities in caves. Biologists have worked with cavers, cave owners and conservation organizations to raise awareness about limiting trips into caves and following national decontamination protocols for clothes and gear.

DNR now urges cavers to reduce trips to Georgia caves. It estimates that about 15 percent of Georgia’s caves are on state-managed lands.

The National Park Service closed all caves at Chickamauga and Chattanooga

National Military Park to the public in 2009 in an attempt to reduce the chance of importation of the white-nose pathogen. Park caves will remain closed to minimize the risk of spreading the disease to other areas.

The National Park Service has seen no evidence of mass mortality in bats due to WNS at Chickamauga and Chattanooga National Military Park. About six dead bats were found at Sittons, although the cause of death was not determined. Researchers there estimated that a third of the some 1600 live bats seen in the cave showed signs of white-nose.

White-nose thrives in the cold, humid conditions of caves and mines. The fungus leads to bats being awakened too often from hibernation and experiencing less intense torpor, causing them to use up their fat reserves. They often starve to death as they leave caves in winter to search for insects that have not yet emerged. There is also evidence the fungus may cause some bats to die from dehydration or electrolyte imbalances. 

There is no known cure for WNS.

Georgia has few known large hibernacula, or hibernation areas. Yet WNS poses a significant threat to the 16 bats species in the state. Of nine species confirmed with either the disease or the fungus so far, eight are found in Georgia. Two, the Indiana and gray bats, are federally endangered species. One, the small-footed myotis, is state-listed as a species of concern.

Bats play a critical role in ecosystems, serving as a natural pest control that saves the U.S. agricultural industry at least $3 billion a year and also helping limit insects that can spread disease to people. Many bat populations are already in decline because of habitat loss. Their ability to rebound is limited by reproduction rates as low as one offspring a year.

“Some bat populations were beginning to recover due to conservation efforts to protect caves and other critical habitats,” Ms. Morris said. “WNS now threatens these populations with significant declines that they may not be able to recover from.”

According to the National Park Service Office of Public Health, WNS does not appear to pose a threat to human health since the fungus that causes the disease only grows at temperatures well below human body temperature. Yet, while people are not at risk of contracting WNS, the public is cautioned against handling bats, which can carry other diseases such as rabies.