Smoky Mountain National Park closes hiking area to protect bats

From the Asheville Citizen-Times

A devastating decline in the Smokies bat population is forcing the closure of a popular hiking area to help protect bats and humans, park managers say.

The 80 percent drop in the Indiana bat population in the park is most likely because of the deadly, rapidly spreading white-nose syndrome. Infected bats are marked by a white fungal growth on their noses, wings and tail membranes.

The White Oak Sink area, around caves where bats hibernate, will be closed through March 31. Park biologists say closing the area around caves will limit human disturbance to bats and help hikers avoid interactions with bats. It has been identified as one of only 13 sites across the country as critical habitat for the federally endangered Indiana bat.

All 16 caves and two mines in the park, which straddles the mountainous North Carolina-Tennessee border, were closed in 2009, said park wildlife biologist Bill Stiver. The first confirmed presence of white-nose syndrome in the park was in 2010, he said.

“Based on estimates from a hasty survey last winter, we’ve lost about 80 percent of Indiana bats. This disease is pretty devastating,” Stiver said. “We are doing everything we can to both slow the spread of the disease and protect the remaining animals by closing caves and areas near caves to the public.”

The area now closed is a popular hiking area of about 450 acres near Cades Cove on the Tennessee side, said Molly Schroer, park spokeswoman. It does not contain any park-maintained hiking trails, and no trails will be closed, she said.

Access to the Whiteoak Sink area is mostly from the Schoolhouse Gap Trail between Townsend and Cades Cove. The closure area is bounded by Schoolhouse Gap Trail and Turkeypen Ridge Trail west to the park boundary. The trails will remain open and closed areas will be posted.

Biologists will monitor the site throughout the winter to collect population, ecological and behavioral data on the bats to help develop a long-term protection plan. The closure might extend through late spring if data suggests it would increase bat survival.

“Normally, bats start entering caves this time of year, called swarming,” Stiver said. “The entrance of caves is where breeding occurs and feeding on insects, just like a bear would. Then they go into caves and live off fat reserves, like a bear. Then they come out in the spring and start to feed.

“White-nose syndrome causes bats to arouse early, and they use fat reserves much quicker, get dehydrated and start starving to death. You have starved bats coming out in the daytime looking for food. With no food source in the winter, they die. We want to minimize human disturbance because it causes them to fly and use up more fat resources.”

The area is also being closed to protect public health, since there have been human-bat encounters.

Infected bats exhibit unusual behavior, including flying erratically during the day, even during winter months, and diving toward people. They may be seen flopping around on the ground around cave entrances.

“Bats are the only mammal in the Smokies that have tested positive for rabies. You can’t always distinguish between white-nose syndrome and rabies.”

The Centers for Disease Control and Prevention says the transmission of rabies virus can occur from minor or unrecognized bites from bats. For human safety, it is important not to touch or handle a bat. The Department of Health and Human Services recommends people seek immediate medical attention if they have had skin-to-skin exposure to a bat.

Mountains and continentwide problem

The park is home to 11 species of bats, including the federally endangered Indiana bat and the Rafinesque’s big-eared bat, which is a state-listed species of concern in Tennessee and North Carolina.

The dying bats in the Smokies reflect the dire situation happening across the Eastern United States and Western North Carolina, which now has 10 counties with confirmed cases of white-nose syndrome, said Gabrielle Graeter, a wildlife biologist with the N.C. Wildlife Resources Commission.

There are now 25 states and five Canadian provinces with confirmed cases of white-nose syndrome. Symptoms of the malady first appeared in bats in 2006 in upstate New York. The disease has since killed an estimated 5.5 million cave-hibernating bats in the Northeast, Southeast, Midwest and Canada.

In WNC, the first confirmed case of white-nose syndrome appeared in February 2011 in an old mine in Avery County. Since then, it has been confirmed in 10 counties: Buncombe, Avery, Yancey, McDowell, Transylvania, Haywood, Rutherford, Jackson, Swain, and, most recently, in Cherokee.

But Graeter believes it is present in every mountain county.

The fungus is spread from bat to bat as they hibernate in caves and mines. There is no evidence that the disease affects humans, but people can transfer the fungus from one cave or mine to another on their footwear, clothing and gear. The public is prohibited from entering any cave or abandoned mine on public lands in WNC, including Pisgah and Nantahala national forests, national and state parks and state game lands.

The species most affected in WNC are the little brown, big brown, northern long-eared, eastern small-footed, Indiana and tri-colored bats, Graeter said.

The U.S. Fish and Wildlife Service is proposing to list the northern long-eared bat as endangered under the Endangered Species Act. The bat, about half the size of a mouse, is found across WNC.

“We have tested some bats outside of WNC, including in the Uwharrie Mountains and in the Piedmont, but none have tested positive with the disease,” Graeter said.

In the 20 sites across the mountains routinely monitored for the disease, where WNS has been present for at least two years, she said the little brown bat had seen a 99.7 percent decline, the tri-colored bat a, 99.3 percent decline and the northern longed-eared bat a 94.5 percent decline.

“There’s an enormous amount of research going on for potential ways to help the bats or slow the situation,” Graeter said. “One of the best things that was done is when the U.S. Fish and Wildlife Service put out the cave advisory (in March 2009), recommending that people didn’t go caving. I think that slowed the long-distance spread of the disease.”

Sue Cameron, a biologist with the U.S. Fish and Wildlife Service in Asheville, said that even where there are not enforced cave closures, there are caving advisories in places where white-nose syndrome has been documented.

“We ask folks to consider not entering caves, and if you do, to take the proper decontamination precautions,” Cameron said. “Putting up bat boxes and not using pesticides and herbicides are little things all of us can do to help the bats.”

Why bats are important

Stiver said bats are just as important to the mountain ecosystem as the black bear. The bat population represents one-fifth of the mammals in the Smokies, which is the most visited national park in the country.

“Bats feed on insects and their guano provides nutrients to the cave ecosystem. They are just as important to our ecosystem in the Smokies as bears.”

There are 11 species of bats in the park, seven of which hibernate in caves. Before the advance of white-nose syndrome, there were an estimated 9,000-10,000 Indiana bats in the park. Stiver said that number is now down to fewer than 2,000.

Bats play a significant role in maintaining ecological balance as the primary predators of night-flying insects. Biologists estimate that an individual bat can eat between 3,000 to 6,000 insects each night including moths, beetles and mosquitoes.

Great Smoky Mountains National Park is working with other parks and federal, local and state agencies across the country to protect bats and manage cave habitats.

A recent plan released by the U.S. FWS aimed at stabilizing the decline of the Indiana bat identified hibernacula (hibernating places including caves and mines) found in the Sinks as one of only 13 sites across the country identified as critical habitat for this endangered bat.

Learn more

Visit whitenosesyndrome.org for more on where the disease has been documented and how to properly decontaminate caving gear.

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