Federal officials are asking people in Kentucky and other states to stay out of caves where bats hibernate to try to stop the spread of a disease that's killing thousands of the flying mammals.
Bats are dying from what the U.S. Fish and Wildlife Service calls "white-nose syndrome." The fungus causes bats to come out of hibernation early, leading to starvation. It hasn't yet showed up in Kentucky, but officials are still asking people to stay out of caves where bats nest.
"It's amazing how fast it's moved south," said Steve Thomas, an ecologist with the National Park Service based at Mammoth Cave National Park. "It's devastating to the bats."
The advisory does not apply to commercial caves like Mammoth, but Fish and Wildlife officials would not rule out possible future restrictions.
The agency issued an advisory last month asking people to stay out of caves where bats hibernate in nine states where the disease has been found — Vermont, New Hampshire, New York, Massachusetts, Connecticut, New Jersey, Pennsylvania, West Virginia and Virginia — and four neighboring states, where it has yet to show up: Kentucky, Ohio, Tennessee and North Carolina.
In caves where the syndrome has been found, 95 to 100 percent of bats have died, said Diana Weaver, a spokeswoman for the Fish and Wildlife Service. Weaver said the environmental impact is not yet known, but "bats are voracious predators of night-flying insects such as beetles and moths or aquatic flies and mosquitoes."
Author and cave explorer Roger Brucker, who has written about Kentucky caves, said bats are known to eat three to five times their weight in insects per night, "and the death of hundreds of thousands of bats means millions of pounds of dangerous mosquitoes and other bugs can overwhelm farm crops, animals, and infect people."
At Mammoth Cave National Park, workers already keep people out of areas where bats hibernate, said park spokeswoman Vickie Carson.
But Carson said there are about 200 other caves in the national park that are only open to researchers who have special permits. Thomas said it is possible that access to those caves could be restricted in the future.
The 700,000-acre Daniel Boone National Forest in Eastern Kentucky is considering a temporary emergency closure of all or most of its caves, said forest biologist Richard Braun.
The policy now, he said, is that all caves are considered open to the public, unless they are posted as closed because they provide vital habitat for one of three endangered species of bats.
Officials of the Great Smoky Mountains National Park, however, have closed all caves over concern about the bat disease. Smokies biologist Bill Stiver said the disease hasn't been found in Tennessee or North Carolina, but closing the caves will help protect native populations of bats against it.