The bat-killing white-nose syndrome is spreading beyond the northeast states where the disease has already killed millions of bats. First discovered in 2006 in a New York cave, the disease caused by a fungus called Geomyces destructans threatens the once-common little brown bat with extinction.
Having wiped out 5.5 million bats by August 2012, the disease continues to spread outward from the original source. In March, the bat-killing white-nose syndrome was confirmed in Georgia and in South Carolina for the first time.
Earlier this month, the US Fish and Wildlife Service (USFWS) found the disease in Fern Cave National Wildlife Refuge in Alabama — an important cave system that provides a winter hibernation gathering place for several species of bats including the endangered gray bat. There is as yet no evidence that the disease kills gray bats, so the wildlife service isn’t sure what impact white-nose will have on their population. However, they know from DNA tests that there are living gray bats in the cave that do carry the fungus.
The disease has virtually wiped out bat populations in Pennsylvania. Greg Turner, a biologist with the Pennsylvania Game Commission, recently checked one abandoned mine that used to hold 8,000 hibernating bats each winter. This spring, there were only 18.
It isn’t particularly clear why the cold-loving fungus that attacks hibernating bats would kill them. One theory is that it’s so irritating that it wakes them too often, causing them to break out of hibernation too early. Emerging from a cave or mine into the winter cold at a time when there is no food, the infected bat then dies of starvation.
Despite the spread of white-nose syndrome into the south, there’s some hope that the disease won’t be as deadly there because of the warmer winters.
The National Wildlife Service said that northeastern bat species populations have already declined by 80 percent, so time is running out to find a cure. They estimated that the value of bats in controlling insects that eat farm crops runs between four to 50 billion dollars a year, so they’re highly motivated to find a way to fight the spread of the bat-killing white-nose syndrome.
[little brown bat infected with white-nose syndrome photo by Marvin Moriarty courtesy US Fish and Wildlife Service Northeast Region via Flickr]