Hibernating bats have been dying in great numbers—90 to 100 % of some colonies—from a disease known as White-Nose Syndrome (WNS), which causes a white fungus to appear on their noses, ears, wings, and tails.

First discovered in 2006 near Albany, New York, WNS has spread rapidly across the eastern United States and Canada, killing more than a million bats so far. The disease is caused by a newly discovered fungus, Geomyces destructans, that infects their skin. Scientists are studying mechanisms of transmission to help stop the spread of WNS.

Four federally endangered species (the Indiana bat, Gray bat, Virginia big-eared bat, and Ozarks big-eared bat) and seven other cave-hibernating bats (the Big brown bat, Eastern small-footed bat, Little brown bat, Northern long-eared bat, Tri-colored bat, Cave bat, and Southeastern bat) are affected by or are potentially at risk from WNS.

A fungus among them

White-Nose Syndrome repeatedly awakens bats during hibernation, causing them to cluster near the mouth of the cave, and sometimes to fly in cold weather. These behaviors deplete the bats’ fat reserves, and they freeze or starve. As more than half of the 45 bat species in the U.S. hibernate, they may also be at risk from WNS.

WNS does not affect humans, but humans who visit caves play an unintentional part in spreading the fungus from cave to cave, as it can linger on clothing and gear. To reduce exposure of hibernating bat populations, authorities have closed many caves to recreational visits.

States and provinces with WNS

By the end of the 2009-2010 hibernating season, 16 states and three Canadian provinces had confirmed cases of bats with WNS. In the U.S.: Connecticut, Delaware, Indiana, Kentucky, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Vermont, Virginia, and West Virginia. In Canada: New Brunswick, Ontario, and Quebec. The fungus associated with WNS has also been found in Missouri and Oklahoma, and in Nova Scotia, Canada.

How you can help

Follow our tips below, and share this info with family and friends.

  • Observe cave closures and advisories, and don’t visit caves in states infected with WNS or in adjoining states. 
  • Do not visit caves when bats are hibernating.
  • Follow the USFWS decontamination instructions for cavers. 
  • Contact your state wildlife agency to report unusual bat behavior, bats dying, or bats with white fungus. 
  • Encourage federal and state legislators to support funding for research on WNS. 
  • If you need to evict a colony of bats from your home, follow recommended techniques, so the bats are unharmed and are not removed until after their young are no longer dependent. 
  • Get the latest news, info, and research on WNS from White-nosed Syndrome.org