decimating bat populations in the Eastern United States. More than a million hibernating bats have died since cave explorers discovered White Nose Syndrome in 2006.
“When a syndrome kills 90 percent of a population, it’s pretty serious,” said Blake Sasse, non-game mammal/furbearer program leader of the Arkansas Game and Fish Commission. “If you are at all concerned about wildlife, this is the biggest mortality event in the U.S. that we’ve ever seen. It could make several endangered species of bats go extinct.”
Researchers first identified the disease in a cave in New York in February of 2006.
The disease continues to affect 16 states and four Canadian provinces. No cases have been reported in Arkansas, but Tennessee has been affected. State cave experts said the white nose fungus could be in Arkansas within a year, according to the Arkansas state parks website.
The distinctive white fungus of WNS grows on the muzzles and wings of affected bats. The fungus, which is not deadly in itself, kills bats because it disrupts their behavior during their hibernation, preventing them from sleeping and subsequently disturbing times when they leave the cave. Bats affected by WNS often leave their hibernacula (caves and mines where they hibernate) during the day. During these flights, they burn calories unnecessarily because there are no insects. The bats eventually lose their fat reserves and then freeze or starve. Oftentimes bats affected by WNS will cluster at the front of the cave or mine where they are hibernating, another unusual behavior.
The disease is spread via contact from bat to bat and possibly from humans who inadvertently carry the fungus from one cave to another on their clothes or caving gear. As a preventative measure, the U.S. Forest Service and the state of Arkansas closed virtually all of the caves in Arkansas state parks in 2010.
“Just about all the caves on public land have been closed to prevent the spread, but we have something like 3,500 caves in the state, most of them are on private property, and the individual landowner can decide whether to allow people in or go in themselves,” Sasse said. “Closing caves to human access is the only preventive measure that we can take. If you choose to go into caves on private lands, you can use bleach to clean gear, boots, clothing and all that; this is not foolproof, but it can help.”
All bats that hibernate in caves can be vulnerable to WNS, according to Sasse. Bats that hibernate in the forest may not be affected. The fungus affects the bats only in the winter months and is found only in caves.
Out of the 45 bat species native to the U.S., more than half depend on hibernation during the winter; conversely, the bat species that migrate during winter have not been affected.
“This disease could make a couple of species go extinct and reduce the bats to a tiny fraction of the population they once had,” Sasse said. “There is not really anything comparable to this in the U.S.”
So far some researchers have managed to treat individual bats, but no one has come up with anything to treat a large number of bats at a time, Sasse said.
