Re-opening caves could lead to spread of deadly white-nose syndrome
By Bob Berwyn
FRISCO — The U.S. Forest Service this week denied an appeal of a new cave-access policy for the Rocky Mountain region, clearing the way for the re-opening of some caves that have been under a blanket closure the past three years to try and prevent the spread of bat-killing white-nose syndrome.
The fungal pathogen was probably introduced to caves in the Northeast by humans and quickly spread to kill more than 7 million bats as far west as Missouri and Oklahoma. Bats are unsung members of the country’s ecosystems, providing valuable insect-control and pollination services.
The Forest Service adopted the new regional policy a few months ago, setting a few thresholds that would trigger strict closures, as well as selectively closing a handful of caves know to be important for bat hibernation. Other measures aimed at protecting bats include required — but tough to enforce — decontamination procedures, as well as a registry to get a better handle on cave use.
Conservation groups, led by the Center for Biological Diversity, say the new policy will make bats in the Rocky Mountain region more vulnerable to the disease, leading to the same widespread devastation of bats seen in the eastern U.S. At this point, researchers know that some caves in the Rocky Mountains have the right combination of temperature and humidity that could allow the growth of the fungus.
Some scientists say it’s nearly inevitable that the disease will spread into the area, while others are hopeful that lower concentrations of bat populations may prevent the spread. Conservation groups wanted the agency to prioritize the protection of insect-eating bats and minimize the chance that people will bring in the disease.
The Forest Service, meanwhile, grappled with trying to balance resource protection with demands for cave access by a small but vocal group of caving enthusiasts, as well as traditional recreational cave use in some areas. According to the Center’s Mollie Matteson, the agency’s own analysis showed that the blanket closure would have done more to protect bats than the new policy.
“The first tragedy of white-nose syndrome is the disease itself,” said Matteson. “The second tragedy is the failure of our government agencies, whose mission is to protect our public lands and wildlife, to do their very best to safeguard the future of these creatures. Thirty years from now, will anyone feel good that caving went on more or less as usual, but the bats that lived in our caves went extinct?”
Seven species are known to be susceptible to the disease, including the federally endangered Indiana bat and the gray bat. A recent study of the Indiana bat predicted the species will disappear across most of its range within a decade. Many bats in the Myotis genus are susceptible to the disease, and several of those live in the Rocky Mountains.
“Bats consume tons of agricultural pests and other insects, thereby providing critical ecological services for human health and stable ecosystem function that far outweigh the purely recreational needs of people at this time,” said Rick Adams, professor at the University of Northern Colorado and president of the Colorado Bat Society. “In fact, with the loss of bats that provide the guano to fuel underground ecosystems, the unique biological values of caves will be lost in our lifetime.”
In response to one of the changes requested by the conservation groups, the Forest Service will require each individual caver to obtain his or her own permit before they visit a cave. But the agency rejected mandatory year-round blanket closures at caves used for winter hibernation, summer roosting, or fall swarming sites by bats, preferring seasonal closures instead. Some individual national forests, notably the White River NF, have chosen to close a few important bat caves year-round.
Wildlife agencies in states affected by the Forest Service rule were luke-warm to the decision, supporting some parts of the agency’s plan, but calling for more targeted year-round closures of at least some caves, since the fungus can persist for long periods in the absence of bats, remaining dormant until bats show up, at which point they can become carriers or active hosts of the disease.