Researchers say a fungal disease that killed bats over the winter has escalated to a crisis.
“We’ve never seen anything of this magnitude — ever,” said Angela Boyer, the endangered-species coordinator for the U.S. Fish and Wildlife Service. “I know of no wildlife disease of any magnitude that has killed this many.”
In Ohio, a survey of a “hibernaculum” — a shelter for hibernating bats — in Lawrence County along the Ohio River found an 80 percent decline in its population since last year because of the disease, called white-nose syndrome, said Jennifer Norris, a biologist with the Ohio Department of Natural Resources. Norris said some species have disappeared from the shelter area.
The disease has spread to bats in nine additional Ohio counties since last year, raising the total to 15.
White-nose syndrome, which kills most bats that contract it, is spreading rapidly throughout the United States, said Rich Geboy, a researcher with the Fish and Wildlife Service. “There is not a cure or a control mechanism.”
There are, however, considerable efforts to combat the fungus, Geboy said, including research into biological and chemical controls.
White-nose syndrome was first documented in 2006, in New York state. Since then, some bat populations have suffered huge losses or disappeared from parts of New York and Pennsylvania. The decline at Ohio’s survey site is comparable to losses in other areas.
Some studies suggest that bats, which eat insects by the ton, save farmers as much as $50 billion each year nationwide. The annual cost savings in Ohio is $700 million.
Significant losses in populations would be difficult for bats to recover from because they reproduce at slow rates, usually producing one pup per pregnancy, Geboy said. One study predicts that the little brown bat, one of the most-common species, will become extinct in the northeastern United States within 16 years, he said.
Katrina Schultes, a biologist with the U.S. Forest Service at Wayne National Forest, said it is difficult to draw conclusions from the Ohio survey site, an abandoned mine.
She said this is the first time that researchers have documented a population decline there. And no dead bats were found — the mammals simply were gone. State officials suspect that the bats were either eaten by scavengers or died outside the cave.
Officials have closed the area’s underground mines to keep out people, who can unintentionally carry the disease. Thousands of caves and abandoned mines in national forests have been closed for the same reason.
“I don’t believe we have any evidence that the spread will stop,” Boyer said. “Decontamination protocol and making sure you’re not inadvertently introducing this fungus into new areas” are important.