Federal officials are scrambling to protect bats in the Black Hills from white-nose syndrome, a catastrophic fungus that has set off a bat apocalypse from New York to Missouri, wiping out more than 6 million of the flying mammals — 90 percent or more of some bat species — over the past six years.
The syndrome's virulence forced the Forest Service to take some drastic steps despite a lack of proof that humans can carry and transfer the fungus to bats. In July 2010, the U.S. Forest Service issued an emergency order to close all caves and abandoned mines for a year in South Dakota, Colorado, Wyoming, Nebraska and Kansas.
The Forest Service extended the ban in 2011, then for another year in August. The closure did not include Wind Cave and Jewel Cave, which fall in the National Park Service jurisdiction.
"Talking to folks back east, there was some thought, 'I wish we would have done something sooner,'" said Kerry Burns, a local wildlife biologist with the Black Hills National Forest. "Our region didn't want to be saying that themselves."
"I think what they have tried to do is adopt a conservative approach because they don’t want to get this wrong," said Joel Tigner of Rapid City, owner of Batworks, a biological consulting business that deals exclusively with bats and bat habitat. "I wouldn't want to be the one making the decisions at this point. It is important enough that you don't want to make mistakes."
But the move rattled recreational cavers who had been accustomed to exploring the numerous named and unnamed caves scattered throughout the Black Hills.
Now, the Forest Service wants to make a final decision on the status of the caves and is drawing up a regional environmental assessment plan it hopes can re-open the caves to exploration but spare the bats a slow communal death.
The environmental plan would create rules for a five-state region in an effort to block the spread of white-nose syndrome into the more than 200 caves and abandoned mines in the area. The Forest Service is taking public comment until Dec. 14 and hopes to finalize the program by July.
"We don't know how much interaction there is of bats in the Black Hills and bats in the east," Burns said. "It may get here, regardless."
On a typical summer night, bat colonies leave their caves and head into the fields to feast on insects, especially mosquitoes, which Hazel Barton, a caving expert and professor of microbiology and geology at the University of Akron in Ohio, calls "popcorn for bats."
A typical bat can eat its body weight in insects every night. Multiply that by the millions of dead bats, and you have an environmental, economic and possibly a public-health disaster coming. Reeder said estimates show that for every 1 million dead bats, there are 694 tons of insects not being eaten every summer.
Researchers say farmers could see crop devastation or be forced to increase pesticide use — adding financial costs to farmers, stressing the environment and possibly endangering the food supply. More mosquitoes means increased treatments by government agencies and a possible spike in diseases such as West Nile virus carried by mosquitoes.
"To the east of the Black Hills, where you have farmland, you could actually see a significant effect," said Barton, who has explored several caves in the Black Hills.
In March 2011, the U.S. Geological Survey partnered with researchers from three universities and issued a report estimating pest control by bats saves the U.S. agricultural industry at least $3 billion and possibly up to $53 billion a year, yet bats "are among the most overlooked, economically important, non-domesticated animals in North America."
The news isn't all bad for the bats. While some species are driving toward extinction, others are showing resistance to the fungus. Researchers wonder whether this is natural selection taking hold, leaving the strongest bat species to thrive.
Exactly how many bats live in the mines and caves of the Black Hills is unclear, but the quantities do not approach those seen in the hardest hit East Coast areas. Bats there can hibernate in clusters of more than 100,000, making the fungus transfer exponentially deadly.
Syndrome is coming
It was a few days before Christmas 2008 when Bucknell University professor and bat researcher DeeAnn Reeder first spotted a bat with a white fungus on its face in a Pennsylvania cave. "I wanted to vomit," she said.
Reeder feared that a crisis was coming. She now spends 85 percent of her research time fighting white-nose syndrome.
"To go into a site where you are literally climbing over carcasses to get in is sad, and it's gross," Reeder said. "On my worst day I feel like we are working our tails off to document an extinction."
In 2006, a bat colony outside Albany, N.Y., developed a white fungus on their muzzles and wings, and the animals dropped dead at an alarming rate. The fungus spread north from Albany and south down the Appalachian Mountain region, then turned west to spread as far as Lincoln County, Mo., just north of St. Louis, where scientists this year confirmed that three bats in two caves had been infected.
About 88 percent of all hibernating bat species in caves and mines in New York, Vermont, Pennsylvania, Virginia and West Virginia have died from white-nose syndrome, according to the Pennsylvania Game Commission.
Exactly how the fungus kills the bats is a matter of debate, but what is known is that the fungus is an irritant, like athlete's foot in humans. Cave bats spend the summer months stocking up on energy, eating vast amounts of night insects to get ready for the winter hibernation. During the hibernation, the fungus wakens the bats, causing them to expend tremendous energy reserves. Once awake, the bats search for food but die of starvation, exhaustion or dehydration. The fungus has also been found to suck water from wings, causing deterioration.
"I've gone to some of these white-nose caves, and you are ankle deep in carcasses," said Barton.
It's widely believed the fungus arrived from Europe, possibly by humans carrying microscopic spores during overseas travel. The syndrome has not been found to harm people. Although many people believe human transportation of spores is happening, no data exists to prove that connection, Barton said. Some research has indicated that bat migration has spread the fungus.
Barton and Reeder both believe white-nose syndrome will spread to the Black Hills, but they don't know how or when.
"I have no doubt that it will get there. I just don't know when. Maybe this year, maybe next," Reeder said. "I would bet money on it, and I don't bet money very often."
That could be devastating for some Black Hills bat species that are the same as those affected on the East Coast. That could signal the start of a new challenge for the agricultural industry.
Cavers are bats' best ally
The ban hit experienced cavers such as members of the Black Hills caving club Paha Sapa Grotto. In August, after two years of outright bans, the government granted special exemptions for National Speleological Society members conducting conservation-related activities, which includes Paha Sapa Grotto.
Dan Austin, Paha Sapa Grotto chairman, said the fungus spread so fast he understands why Forest Service officials reacted swiftly. However, with little hard science to prove humans are spreading the fungus, the closures were heavy-handed, he said.
"We never agreed with blanket cave closures," Austin said by email. "We have always felt from the start of the emergency order in Region 2 that a targeted approach to closing specific, sensitive caves with bats would be the most valuable."
Burns, the local wildlife biologist, said local cavers may be the key to preventing or recognizing the white-nose syndrome as it moves west. Austin said his group is happy to join the fight.
"They know that we’re the experts," Austin said, "and that we can help them with cave management and further white-nose syndrome studies, whether it be monitoring certain caves or inventories."