The frequent disruptions apparently cause the bats to burn too much body fat. They leave the cave too soon in search of food that isn't there, and they starve.
By 2007, the contagion had spread to more caves in upstate New York. By late winter 2008, it was devastating hibernation sites, or hibernacula, in Vermont, Massachusetts and Connecticut. Hundreds of thousands of bats died, 90 percent to 100 percent of each colony.
Inspections this winter have confirmed more white-nose bat mortality in mines and caves in northwestern New Hampshire; northern New Jersey; Lackawanna, Mifflin and Luzerne counties in central Pennsylvania; and four sites in Pendleton County, in West Virginia's eastern panhandle.
In western Virginia, bats in Bath and Giles counties have been found with the white fungus on their faces and wing membranes. Those cases are listed as "likely," pending lab confirmation.
Why Maryland bats have been spared so far isn't clear. Feller thinks it might be because Maryland caves are not interesting enough to attract cavers active in affected areas of the country.
Unlike Maryland's hibernacula, the Virginia caves are "large, complex systems that are extremely popular with cavers," Haskew said. Cross-checks of the logbooks cavers sign have found instances of people visiting the West Virginia and Virginia caves after exploring the "ground zero" cave in New York where the outbreak began.
On March 26, the U.S. Fish and Wildlife Service urged cavers to "curtail all caving activity in WNS-affected states and adjoining states." And when exploring elsewhere, cavers should use clothing and gear that has never been used in white-nose affected states, or in states adjoining them, the agency said.
The government, and such cavers' groups as the Northeastern Cave Conservancy and the National Speleological Society, are urging people to stay out of bat hibernacula in winter. They've issued detailed protocols for cleaning and decontaminating clothes and cave gear. Caving groups also have closed some of the caves they own or control during bat hibernation.
Peter Youngbaer, white-nose liaison for the speleological society, said caving groups are also conservation organizations. A cavers' "Crawlathon" in Kentucky was canceled in January with just three days' notice out of concern that some of the 700 participants might bring the fungus into the state.
