Bat health isn't on everyone's radar, but it should be, biologists say.
Bats are the only night-time bug killer over our agricultural fields,
and their feasting saves farmers billions of dollars they'd otherwise be
spending on pesticides and losing in crop failure. They are crucial to
rare cave life, their guano feeding microorganisms that feed
invertebrates that feed the fish and salamanders and other creatures.
But America's bats are dying, the victims, either directly or indirectly, of what's called white-nose syndrome, a fungal infection that has spread through bat populations from New York north to Vermont and south to Tennessee in just four years. Fungus-encrusted bats are waking up and flying out of their wintering caves too early to find sustenance and are starving. The situation is dire, with mortality rates of nearly 100 percent in infected caves. Scientists are particularly fearful that endangered species — like Arkansas's Ozark big-eared bat, the Indiana bat and the gray bat — could become extinct.
Humans can't control bat migration, but they can — on public lands, at least — control human movement. To stop the spread of fungal spores on clothing and shoes, federal and state agencies have begun to close caves on their lands to all but biologists, and even the scientists are being restricted.
Last year, the Eastern region of the U.S. Forest Service ordered the closing of caves on NSF lands. Blanchard Springs Caverns, a commercial cave operated by the Ozark-St. Francis National Forests, is still open for tours but spelunkers who explore the wilds of the cave may only use gear provided at Blanchard, to guard against contaminants picked up at other caves.
The state Game and Fish Commission voted last week to close caves on its lands and natural areas it manages for the state to the public. At Devil's Den State Park, the Devil's Den and Devil's Icebox are still open to visitors but Farmer's Cave is shut and concerns are growing about the Devil's Den and Icebox, park naturalist Adam Leslie said. Visitors to the park are being asked if they've been to Tennessee or other fungus-infected states, Leslie said; those numbers are low, fortunately.
The Buffalo National River, which is part of the National Park Service, has closed most of its caves to spelunkers, with the exception of caves in Lost Valley from Eden Falls Cave to the parking area and those at Buffalo Point (but Bat Cave there is closed). It is also requiring special permits for all research activity in caves and mines. Park geologist Chuck Bitting said caves left open were those that get so much public traffic that it would be impractical to close them.
The Park Service, like other federal agencies, has kept closed caves that contain colonies of endangered bats for many years. Bitting said 15 or 16 caves along the Buffalo have been closed either seasonally or year-round to protect populations of Ozark big-eared bats and Indiana bats. Now, about 350 caves will be closed.
Bitting said he's heard some griping about the cave closings. “People aren't happy about it. I don't blame them. I'm not real happy we had to do it. It's a big recreation activity, for a small portion of the population.” He said only one or two cavers have “railed” about the closings, but that they've always been unhappy about closed caves.
David Kampwerth, the cave and karst biologist in the Arkansas office of the U.S. Fish and Wildlife Service, says the closures have limited “quite a bit of caving activity” in Arkansas and sent spelunkers to caves on private lands. One of the concerns of cave biologists is that cavers may not be decontaminating their gear as the move from cave to cave. The USFWS recommends that cavers wash all gear, apply disinfectants and wash again to remove the disinfectants.
Kampwerth says cavers should be decontaminating their gear white nose or no, since microorganisms that are part of the ecosystem in one cave may cause disruption in another. Research has shown that Geomyces fungi (white nose is caused by a new species, Geomyses destructans) can be transferred from one site to another on gear. It's an inconvenience, he says — he may spend up to three hours decontaminating the multiple sets of gear he'll use in a day of multiple cave visits — but something he's done in his 30-plus years of caving.
“I feel for people that have been closed out,” Kampwerth said. “But until we know a whole lot more it appears to be the right
thing to do.”
The National Speleological Association, and its Arkansas affiliates, urge their members to follow USFWS protocols in cleaning gear.
While closing caves to public access may slow down the spread of the fungus, bat-to-bat infection is the ultimate threat. In February, Tennessee wildlife authorities reported that tri-colored bats — formerly known as Eastern pipistrelles — hibernating in a cave in Sullivan County in the eastern part of the state were infected. If Tennessee's populations of gray bat, an endangered species known to range widely and whose range includes Arkansas, become infected, the fungus could spread to Arkansas within a couple of years.
Most of Arkansas's caves are on private lands, and biologists are hoping to get the word out to landowners of the dangers. Commercial cave owners are, predictably, hesitant to shut down their businesses, though their plans range widely. The owners of Cosmic Cavern in Berryville are partnering with a bat conservation outfit in Austin, Texas, to provide information to their visitors about the disease. (They say only six bats use their cave, so they have no plans to close or require visitors to decontaminate their shoes.)
But Steve Rush, owner of Mystic and Crystal Dome caves in Harrison, said he plans to rid his caves of the bats so people can keep coming. He said he'll screen off the gaps around the metal doors that are at the entrances to his caves in June, after the bats have left for the summer, and won't let them back in.
Rush, who says he gets between 14,000 and 15,000 visitors a year, is skeptical about whether the fungus is actually killing the bats and whether people are transferring the spores.
“We don't want the government interfering with our cave operation,” Rush said. Did he think that likely? “We're about to have public health care even though nobody in this country wants it.”
(On the “About Us” page on his Mystic Caverns website, Rush says he used to care more about making money than people, but Jesus changed his priorities. Now, he writes, he wants people to come to Jesus even if they don't come to tour Mystic or Crystal Dome. Tours, apparently, outrank the bats.)