Thursday, October 2, 2014 · 6:24 a.m.

Bat-killing fungus spreads south, confirmed in Lookout Mountain Cave

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Infected tri-colored bat found in an Alabama cave. (Photo: USFWS)

White-nose syndrome is one of the most dire wildlife epidemics in U.S. history, responsible for the deaths of nearly 7 million hibernating bats in eastern North America.

First documented in a commercial cave in New York during the winter of 2006, white-nose syndrome is making a catastrophic march south, threatening the survival of southeastern hibernating bat species and the ecosystems they support.

Tennessee’s first documented case of white-nose syndrome was recorded in Sullivan County in February 2010, with additional occurrences recorded in 2010 and 2011, including a cave within the Great Smoky Mountains National Park.

Last month, the disease was confirmed in a backcountry cave on Lookout Mountain within the Chickamauga and Chattanooga National Military Park. Two tricolored bats with visible signs of the fungus Geomyces destructans, which causes white-nose syndrome, were collected. One bat tested positive for the disease.

An infected bat. (Photo: Ann Froschauer, USFWS)

Ecologist Steve Thomas, the National Park Service monitoring program leader for the Cumberland/Piedmont Network, made the discovery in April during a bat-monitoring project within the park. In March, Thomas discovered tricolored bats infected with white-nose syndrome in the Russell Cave system in Alabama as well.

“Tricolored bats appear to be a fairly common bat in the Southeast, but that may change because of this threat,” Thomas said. “We don’t know what is going to happen.”

In northeastern states, where white-nose syndrome has been present the longest, bat populations have decreased by more than 90 percent. Biologists believe several bat species may become extinct as a result of the disease.

White-nose syndrome invades and ingests the skin and wings of hibernating bats, causing bats to wake up more frequently during winter hibernation, possibly because of water loss from damaged tissue. Bats aroused from hibernation burn up limited winter fat reserves and often starve to death because of a lack of insects during cold months. In some cases, their wings are too damaged to fly. Dead or dying bats are frequently observed with white fuzz around their muzzles, hence the name white-nose syndrome.

The disease is believed to be transmitted from bat to bat, but there is increasing evidence that it may also be transmitted by humans carrying the fungus from cave to cave on footwear, clothing and gear. For this reason, most caves on federal lands in the eastern and southern United States have been closed to nonessential access for the past several years.

In 2009, the State of Tennessee, the National Park Service, USDA Forest Service and the Tennessee Valley Authority closed caves on public lands in Tennessee as a precaution against human transport of the bat disease. The Nature Conservancy also closed caves located on their lands in Tennessee.

Currently, there is no known cure for white-nose syndrome. However, biologists with state and federal agencies and organizations across the country are working frantically to find a solution for this deadly disease. In March 2012, the U.S. Fish and Wildlife Service announced grants totaling approximately $1.6 million to continue the investigation of white-nose syndrome in bats and identify ways to manage it.

“White-nose syndrome is unlike any other wildlife disease we have ever seen,” said Ann Froschauer, national white-nose syndrome communications leader for the U.S. Fish and Wildlife Service, which is leading the national white-nose syndrome response effort. “It is likely that we could lose entire species of bats if the disease continues on its current course.

“Because the disease is spreading so quickly, and we have never seen anything like this before, it will require a completely new way to manage it,” Froschauer said. “However, I feel like there are a lot of dedicated scientific minds working on this.”

Bats account for about 25 percent of all mammals on Earth and provide enormous ecosystem services, consuming millions of pounds of night-flying insects each year and keeping in check bugs that are problematic for agriculture and forestry.

The loss of bats could trigger massive insect explosions, with catastrophic impacts on agriculture and human health. Pest-control services provided by bats in the United States have been valued at $3.7 billion to $53 billion per year, according to a study by Gary McCracken, head of the Department of Ecology and Evolutionary Biology at the University of Tennessee in Knoxville.

To learn more about white-nose syndrome (maps, decontamination information for cave visitors and other details), visit www.WhiteNoseSyndrome.org.

Tennessee’s radical effort to save bats
Tennessee has more than 9,600 documented caves—more than any other state in the nation. These caves provide homes for 16 species of bats, including endangered Indiana bats and gray bats.

In an experimental effort to protect Tennessee’s bats from white-nose syndrome, The Nature Conservancy in Tennessee, in partnership with the University of Tennessee-Knoxville and Bat Conservation International, will begin construction of an artificial bat cave outside of Clarksville, Tenn., this summer. The artificial cave, to be built next to an existing natural cave, will serve as a safe haven for hibernating bats and a controlled environment for research.

One benefit of an artificial cave, according to Cory Holliday, cave and karst program director for The Nature Conservancy in Tennessee, is that it can be disinfected with anti-fungal agents to rid the cave of the fungus that causes white-nose syndrome, whereas a natural cave cannot.

“The fungus is really susceptible to a lot of things, such as heat and anti-fungal agents, but you can’t do what needs to be done in a natural cave setting because it would destroy other cave life forms as well,” Holliday said. “This artificial cave is a pilot project, but if it works, we are hopeful that we can build a lot of these things.

“This artificial cave not only has the potential to save a large colony of bats from white-nose syndrome, but also to serve as a model that could be replicated anywhere [the disease] threatens to destroy a significant colony of hibernating bats,” Holliday said. “This is the first idea we've come upon that offers bats a real chance at survival without killing the other organisms that call caves home.”

To learn more about the artificial bat cave or to make a contribution toward the effort, visit The Nature Conservancy of Tennessee website.

Jenni Frankenberg Veal lives on Walden’s Ridge and enjoys writing about the natural world and exploration opportunities found within the southeastern United States, one of the most biologically and recreationally rich regions on Earth. Visit her blog at www.YourOutdoorFamily.com.

USFWS staff member Ann Froschauer inspects a healthy big brown bat. (Photo: USFWS)
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