The common little brown bat might all but disappear in the East and possibly the Midwest if the fungus continues to spread. They also fear for the northern long-eared bat and the Indiana bat.
A white-nose death is grisly. The fungus hits when the bats’ breathing is low and their tiny heartbeats are at an ebb in hibernation.
Scientists at the U.S. Geological Survey and the National Institutes of Health theorize that the bats die when they awaken from hibernation, and their reactivated immune systems go overboard in an attempt to eliminate the intruding disease, destroying the illness but also tissue bats need to live. Ligaments in the wings of bats appear scorched.
There was positive news in 2011 that a few little brown bats in the Northeast were resisting the disease, hanging on to existence “by a tiny little fingernail,” a Vermont conservationist said. But in the past two years the disease spread south and as far west as Iowa.
Days before Christmas, reports of erratic behavior started coming in to the ranger station at Great Smoky Mountains National Park, which boasts 275 million visitors a year. As a precaution, officials warned visitors to beware of bats because of the risk of rabies. Bat teeth are so small that people might not know they had been bitten.
But Stiver said the behavior is consistent with white-nose, which was most lethal in the Northeast after three years. “And what do you know, it’s been here three years,” Stiver said.
There are 11 species of bats in the 500,000-acre park, representing a fifth of all its mammals. Bats that fly around in the winter are doomed, even when they don’t have white-nose. They use up fat reserves stored for the winter and starve because the bugs they eat are hibernating.
At this point, bats are in a deadly endurance test, Stiver said. Some might develop an immunity to the fungus, as have bats in Europe, from where Geomyces destructans was likely brought, wildlife biologists say.
Otherwise, the observation of Mylea Bayless, conservation programs manager for Bat Conservation International in Austin, might prove correct.
“We’re watching a potential extinction event on the order of what we experienced with bison and passenger pigeons for this group of mammals,” she said.