A disease that already has killed nearly 7 million bats in the eastern United States in the past five winters has hit home in one of the region's best-known cave systems.
Wildlife officials have confirmed white-nose syndrome in Russell Cave near Bridgeport, Ala., about 29 miles west of Chattanooga.
The Russell Cave complex features miles of passages, with entrances on both private land and the Russell Cave National Monument, operated by the National Park Service. Researchers have found evidence of continuous human occupation at the cave over the past 10,000 years.
Molly Matteson, a bat specialist with the Center for Biological Diversity of Tucson, said the discovery of the disease in Alabama - a first this far south - is particularly troubling to biologists because Alabama hosts the country's largest wintering colony of federally endangered gray bats.
If the species proves susceptible to the fungus that causes white-nose syndrome, it could be devastated in a short time, she said.
All bats are an important weapon against mosquitos and agricultural insect pests, she said.
Officials at Russell Cave National Monument said the park already has taken precautions to try to protect the cave bats by closing the wet part of the cave, even to researchers.
"We closed the cave to cavers in 2000, and in 2009 with the white-nose scare, we stopped even researchers from going in," said park biologist Mary Shew. "What still is open, and always has been and will be, is the large rock shelter opening. So as far as visitors to the park, it will be business as usual here."
The cave still houses thousands of bats from at least seven species, she said.
Experts say bats are more important to humans than most people realize, capable of eating up to half their body weight in insects in just one night.
"One little brown bat may catch 600 mosquitoes per hour," said Shew.
Scientists have determined the disease is caused by a previously unknown fungus, likely introduced by cave visitors from Europe, where the fungus has been discovered on bats from France to Hungary but appears to do little to no harm.
In the United States, however, it is having a devastating affect.
In recent years, federal officials have closed caves throughout the region. Recreational cavers who still can access privately owned caves are asked to follow strict gear-cleaning protocols to help slow the progress of the fungus.
But the disease also can be spread from bat to bat, and no one can stop the bats' migration patterns.
The fungus causes bats to waken prematurely from winter hibernation. They often die after they fly into the cold air in search of insects that have not yet hatched or come out of hibernation themselves.
Before white-nose syndrome, bats have been long-lived small mammals with average life spans of about 20 years, but they reproduce slowly, with mother bats having just one pup a year.
Matteson said even if bat populations can recover from the white-nose decline it will take many years, so their role as nature's pest control will be noticed quickly and over a long period of time.
"White-nose syndrome has been an emergency from the beginning, but it's now a Category 5," she said. "Our government needs to put serious money and science into solving this disease storm before it's too late."