Caves Closed In U.S. To Slow Bat Disease Spread

There is no known human health risk associated with WNS in bats. While the actual cause of WNS is unknown, scientists are reasonably certain that WNS is transmitted from bat to bat. However, WNS has been found in caves a significant distance from WNS-affected hibernacula, leading scientists to suspect humans may inadvertently carry the fungus from cave to cave where bats hibernate.

"Although we have not seen this disease in Indiana, the responsible thing to do is close our caves to help slow expansion of WNS," said DNR director Robert E. Carter Jr. in announcing the decision. "Scientists need time to get a handle on the problem and solve it."

The voluntary action is effective May 1 and closes public access to all caves, sinkholes, tunnels and abandoned mines on DNR-owned land, except Twin Caves at Spring Mill State Park. Twin Caves is able to remain open because it is a water cave with controlled boat access only and the WNS fungus settles in soil.

The closure extends through April 2010 and follows similar steps taken elsewhere in response to a U.S. Fish & Wildlife Service advisory asking cavers to curtail cave activities in WNS-affected states and adjoining states. The Hoosier National Forest has closed all caves, as has Great Smoky Mountains National Park.

List of closed caves.

"As (this) spreads, it threatens bat populations not only in the northeastern United States, but in the Midwest as well," said U.S. Fish and Wildlife Service Regional Director Tom Melius. "The Service strongly supports Indiana's pro-active approach to safeguard the state's bats. The Hoosier state is home to critically important hibernacula for endangered bats, and we believe Indiana's action is a significant step in keeping white-nose at bay as we work together toward a solution."

Three commercial cave operations-Blue Springs Caverns, Marengo Cave and Squire Boone Caverns-will remain open, and the DNR and U.S. Fish & Wildlife Service are working with those businesses to develop appropriate steps to minimize the spread of WNS.

The DNR also is working with owners of private caves where significant bat hibernacula are known to exist to encourage them to close access.

The population density of bat species in the southern part of Indiana, especially the federally endangered Indiana bat, prompted the cave closures on DNR sites.

"We have a really strong reason to be cautious," said Katie Smith, head of DNR's Wildlife Diversity Section. "Indiana has thousands of cave-dwelling bats, and this devastating disease puts them all at risk. Bats are important to our ecosystem and natural heritage, and we must take every reasonable precaution to protect them."

The disease got its name because affected bats appeared to have a white substance on their heads, often around their noses, and on their wings. WNS has killed an estimated 500,000 bats from Vermont to West Virginia and continues unchecked. In some hibernacula, there has been 90 to 100 percent mortality.

WNS was first recorded in 2006 in a cave near Albany, N.Y., and within two years had spread to Connecticut, Massachusetts and Vermont. Bat deaths were confirmed this past winter in at least seven states, including new outbreaks in Virginia and West Virginia.