White-nose syndrome precautions debated by cavers
July 21, 2011
GLENWOOD SPRINGS, Colorado – As scientists are still learning all they can about the devastating white-nose syndrome in bats, every precaution is being taken to prevent the spread of the deadly disease.
Much of that effort is focused on the western part of the United States, including Colorado, where bat populations have so far been unaffected by the disease.
The National Speleological Society (NSS) convention included an afternoon session Wednesday devoted entirely to the topic, “White Nose Syndrome – A Western Perspective.”
The annual gathering of recreational cavers and cave scientists continues at Glenwood Springs High School through Friday, including a full slate of caving presentations, discussions about cave conservation efforts, photography and mapping workshops, business meetings and other activities.
While the disease itself has not been detected west of Tennessee and Kentucky, the fungus that causes white-nose syndrome has shown up in Missouri and Oklahoma. That has led to speculation that it’s only a matter of time before it makes its way west.
One of the major questions, though, is the impact humans might have in spreading the disease, beyond the obvious spread from bat to bat.
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The Wednesday discussion included federal and state wildlife and land management agency officials and scientists who are working on climate models and other studies to assess the risk that the disease could move west.
“We are very concerned that we will see white-nose syndrome,” said Phil Nyland, a U.S. Forest Service biologist with the White River National Forest, based in Glenwood Springs. “I have talked to people who say, ‘oh, it will come.’ But part of our job is to do what we can to try to prevent that.”
Last summer, the Forest Service imposed a one-year emergency closure order for all caves on forest lands as a precautionary measure. The closure expires next week, but is expected to be extended for another year.
Nyland was in charge of issuing permits for the NSS to lead specially authorized trips into caves on the White River Forest during this week’s convention.
A total of 17 caves were identified where bat activity was determined to be minimal or nonexistent, and permits were issued for those caves. The NSS was also required to follow a strict decontamination procedure for any equipment and clothing used in the tours.
Two caves located on U.S. Bureau of Land Management land were also included in the tours. A federal court ruling upheld those permits after a legal challenge was filed by the Center for Biological Diversity.
“There is strong evidence that the fungus that causes the disease can be transported by humans,” said Ann Froschauer of the U.S. Fish and Wildlife Service, which is coordinating with federal land agencies and individual state wildlife agencies on the issue.
“This disease has resulted in one of the most precipitous declines in a wildlife population that we’ve ever seen,” she said. “There has been a massive response to find out as much as we can, as quickly as we can, about this disease.”
Meanwhile, avid cavers and NSS members say they share the concern about bat populations and the spread of white-nose syndrome. But they question the policy of closing caves to human access as a preventative measure.
Two of the NSS’s primary purposes, cave conservation and cave access, are pitted against each other in the debate, said Carl Bern of the Colorado Cave Survey, who led the discussion.
“We’re always trying to strike a balance between those two, and often it does come down to judgment calls,” he said.
There are different circumstances in the western states that could work in the region’s favor in terms of controlling the spread, as compared to the eastern states where bat populations have been decimated by the disease over the past five years, Bern said.
One is the fact that much of the land where caves exist is controlled by the Forest Service and BLM. The other is that the climate, especially at higher elevations, and bat behavior is different than in the eastern states.
Any evidence that humans are responsible for spreading the disease is purely “speculation and hypotheses,” said Peter Youngbaer of Vermont, who is the official NSS liaison on white-nose syndrome.
“There is evidence, however, that cave closures don’t necessarily prevent human access to caves,” he said, adding that the closures are only keeping responsible cavers out, meaning they aren’t on hand to keep the less-responsible cavers from going in.
Youngbaer said the numbers suggest the western states are less likely to see the kind of devastation in bat populations as in the east.
Of the total 55,790 or so known caves in the United States, only 8,250 are in located in the Rocky Mountain and Pacific coast states, he noted. Also, while caves in the east are home to bat colonies in the range of 4,000 bats, colonies found in western caves are much smaller, limiting the chance that the disease will spread as quickly as it has in the east.