Could a fungus cause the extinction of bats?

What Is White Nose Syndrome?

A little brown bat (Myotis lucifigus) with the white fungus covering its muzzle and body.
A little brown bat (Myotis lucifigus) with the white fungus covering its muzzle and body.
Photo courtesy New York Department of Environmental Conservation

Like a case of chickenpox in a kindergarten classroom, the bat pestilence moved fast after it first cropped up in Albany, N.Y. By spring 2008, evidence of bat deaths showed up in Massachusetts, Pennsylvania, Connecticut and Vermont, slicing the bat population in some hibernation caves from 15,000 to 1,500 [source: Hill]. The New York State Department of Environmental Conservation took the lead in 2007 to investigate what was decimating the bat population. They named the malady White Nose Syndrome (WNS), for the white fungus primarily found on infected bats' noses, wings, ears and tails.

The research conducted by the New York State Department of Environmental Conservation showed that WNS had spread to almost every cave within an 80-mile (128-kilometer) radius from the infected ones discovered in 2007 [source: Hicks]. That translates to about half a million bats exposed to WNS [source: Hicks]. Infected bats likely spread the syndrome to nearby caves by coming into contact with healthy bats during warmer summer months.

Five bat species in particular have been struck by WNS: little brown myotis, Indiana myotis, northern myotis, eastern small-footed myotis and eastern pipistrelle [source: Bat Conservation International]. Scientists don't know how far or fast WNS could spread, but it could potentially reach Ohio and Virginia [source: Hicks]. With a mortality rate between 80 and 100 percent, the syndrome could seriously threaten the future of these affected bat species [source: U.S. Fish and Wildlife Service]. The Indiana myotis especially concerns wildlife specialists because it's already federally classified as an endangered species. Its global population hovers around 550,000, but the Indiana myotis tends to cluster together in large numbers, which means an infected cave could cripple any chances of recovery [source: New York State Department of Environmental Conservation].

The U.S. Fish and Wildlife Service has stepped in as well to try to pinpoint what's causing the problem. According to Bat Conservation International, specialists suspect one of three scenarios:

  • An unknown virus or pathogen
  • Varying hibernation patterns due to climate change and warmer winters
  • Decreased food supply due to man-made pesticides that kill insects, leaving bats without enough fat to make it through winter

But what about all that white fungus? Isn't that the culprit? Because the fungus isn't found uniformly on all bats, the fungus is likely a symptom rather than the root of the problem [source: U.S. Fish and Wildlife Service]. So far, researchers haven't isolated a WNS pathogen or bacteria from the dead bats. The bats' emaciation has led some to suspect that WNS is linked to some type of alteration in their metabolisms, although that hasn't been confirmed.

Teaming up with volunteers and researchers at colleges and universities, government officials are scrambling to solve this puzzle. Although no one has reported any human side effects of WNS, warnings have gone out to cavers in infected areas to take precautions like cleaning their clothes and shoes when they exit caves to ensure they don't spread WNS. Some caves have even been closed off for research.

So far, experts haven't connected the dots to WNS. But they do know one thing: It moves quickly, and time is not on the bats' side.

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More Great Links


  • "Bat Basics." Swartz Lab. Brown University. (July 31, 2008)
  • Hicks, Alan. "White Nose Syndrome: Background and Current Status." New York State Department of Environmental Conservation. March 30, 2008. (July 31, 2008)
  • Hill, Michael. "Bat Deaths in NY, Vt. Baffle Experts." Associated Press. LiveScience. Jan. 31, 2008. (July 31, 2008)
  • "Indiana Bat Fact Sheet." New York State Department of Environmental Conservation. (Aug. 5, 2008)
  • Metzer, Jim. "Listening In on a Bat Cave." NPR. May 6, 2008. (July 31, 2008)
  • "Mysterious Bat Die-Offs." Bat Conservation International. March 25, 2008. (July 31, 2008)
  • "The White Nose Syndrome Mystery: Something Is Killing Our Bats." U.S. Fish and Wildlife Service. (Aug. 5, 2008)