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White-Nose Syndrome (WNS)

White-Nose Syndrome

What is it?

First documented in New York in the winter of 2006-07, White-Nose Syndrome is believed to have surfaced in Pennsylvania in 2008 and began killing cave bats in 2009. WNS refers to a white fungus on the muzzles and wing membranes of affected bats. Because this fungus is a cold-loving fungus, it is a condition that only affects them while they hibernate. Therefore, it is not harmful to humans, and does not grow on bats during the summer months or when bats are at typical active temperatures. This fungus has been confirmed to be the causative agent of the disease, although the specific mechanism in how it causes mortality is not fully understood.


Decreasing Disease Impact

The exact mechanism by which WNS causes mortality is unknown. However, it has been shown that when bats become infected by the causative agent, a fungus called Geomyces destructans, the bats arouse too frequently causing a severe depletion of fat reserves. Although most sites in Pennsylvania have now been contaminated by this fungus, preliminary research in Pennsylvania documents all survivors still become infected annually. It is likely that these few survivors are existing on limited fat reserves, and every disturbance is an additional cost on those reserves. The effect of this disturbance may directly cause mortality later in the hibernation season to adults or juveniles fighting infection, or it may lower the fitness of adult females enough to inhibit their ability to successfully reproduce. Therefore, the Pennsylvania Game Commission strongly recommends that recreational caving not occur at any hibernacula during the months when bats are hibernating (October 1- April 30).


WNS at Shindle Mine, Mifflin County This 3-minute video features a look at bats inside a mine and an interview with Game Commission biologist Greg Turner in 2009

The Race to Save Pennsylvania's Bats originally premiered in Pittsburgh on January 23, 2012, as part of WQED's documentary series, Experience. The 28-minute video features  interviews with Pennsylvania Game Commission biologists Greg Turner and Cal Butchkoski.

White-Nose Occurrence Map

White-nose syndrome has affected bat hibernaculum throughout all of Pennsylvania. It can also be found throughout most of the eastern United States and Canada, as well as the staet of Washington. Each winter, white-nose syndrome and its causative fungus continue to spread across North America.

White-Nose Syndrome Occurrence Map