A mysterious disease threatens to wipe out America's bats.
By Amy Leinbach Marquis
The killer crept in quietly while the victims were sleeping, all huddled together in little brown clumps in a cave in Albany, New York. First, a small, white ring of fungus appeared around the noses of several species, including Myotis lucifugus—commonly called little brown bats. Soon they became emaciated. And then, one by one, they began dying, their tiny winged carcasses piling up on the floor. What was once a safe and reliable shelter for thousands of bats quickly turned into an eerie grave.
More than 8,000 bats died in the Northeast in the winter of 2006. Since then, the mysterious disease—called white nose syndrome—has wiped out more than 500,000 bats. It has affected six different species— including several small populations in Delaware Water Gap National Recreation Area in Pennsylvania and New Jersey—and may spread as far south as Virginia. Since white nose syndrome may kill 80 to 100 percent of bats once it infects a cave, biologists are nervous about its proximity to the Southeast, which provides some of the world’s best habitat for hundreds of thousands of bats, including endangered gray bats and big-eared bats.
But how can scientists manage a disease they know so little about? The white fungus offers some clues—it thrives in cold temperatures, for example—but some people don’t believe it’s the single cause of death, if it’s causing the deaths at all. It may just be one of many contributing factors. So what, then, is the source of this silent killer? And how can it be stopped?
To find answers, the Park Service is engaged in research projects and establishing new management plans with help from leading scientists and other federal agencies. They’ve learned that bats are probably vectors of white nose syndrome, and humans might be, too, considering fungal spores might be capable of clinging to clothes and shoes. In response, rangers in Cumberland Gap National Historical Park in Kentucky, Tennessee, and Virginia, are monitoring visitors closely to make sure they’re not wearing the same clothing and gear in one cave that they’ve recently worn in another.
Back at the Delaware Water Gap—the only national park to show signs of the disease—rangers took a more extreme measure by shutting caves to the public last spring. The U.S. Forest Service has closed thousands of caves in dozens of states. Rangers have even banned recreational spelunking as a precautionary measure as far west as Sequoia and Kings Canyon National Parks in California and as far south as the Great Smokies in Tennessee and North Carolina. “We can’t stop an infected bat from flying here,” says Dan Nolfi, a wildlife technician in the Smokies. “But closing caves to people is one way we might be able to help control the spread.”
Whether you’re fond or phobic of bats, it’s hard to deny the benefits of having them around. One little brown bat can eat anywhere from 500 to 1,000 mosquitoes in a single hour; other bat species keep cropeating beetles and moths under control. And there may be many other benefits we’re not even aware of.
“We can’t begin to say that we know everything about how bats affect ecosystems, and it would be irresponsible of us to think that we do,” says Kevin Castle, a National Park Service wildlife veterinarian who’s taking the lead on white nose syndrome for the agency. “That’s just one of many reasons why we need to try to keep bats around.”