TRAVERSE CITY — A fungal disease that has killed millions of North American bats is spreading and now has been detected in half of the United States, officials said Thursday.
Wildlife agencies in Michigan and Wisconsin said they had confirmed diagnoses of white-nose syndrome in tested bats, further evidence of the ailment’s rapid expansion since it first was documented in a cave near Albany, N.Y., in 2006. Cases have turned up in most states east of the Mississippi River, with Georgia and Alabama joining the list in March, and as far west as Missouri and Arkansas.
Officials said the latest discoveries were no surprise but a cause for sadness, acknowledging they had no cure and could take only limited steps to protect the winged mammals that provide an enormous economic and ecological benefit by feasting on nuisance insects that gobble crops and trees.
“We face the loss of multiple bat species and the benefits they provide to our ecosystems and our people,” said Erin Crain of the Wisconsin Department of Natural Resources.
White-nose syndrome is named for the fuzzy spots it plants on victims’ muzzles, wings and tails. It doesn’t affect people or other animals but repeatedly interrupts bat hibernation, sapping their energy and fat stores, which can cause starvation and dehydration.
More than half of the 45 bat species in the U.S. hibernate during winter. Many seek out caves or mines, an ideal environment for spreading the killer fungus as bats clump together on the moist walls.
Some might survive if they contract the illness late enough in winter. But the refuge could be a death trap for those that return the following year. And some will move on to other enclosures and infect them — particularly during fall mating season when huge flocks of bats sweep in and out of caves and mines, said Allen Kurta, an Eastern Michigan University scientist.