White Nose Syndrome

White Nose Syndrome

WNS title pic

White-Nose Syndrome (WNS) is caused by an invasive white fungus, named Pseudogymnoascus destructans or Pd, which was formerly known as Geomyces destructans. Pd is found in soil, water and air, and is native to Europe; it thrives in cold environments (between 10-14 degrees Celsius) and infects bats dermal tissue during hibernation.

WNS, was first discovered in 2006, when biologists with the Department of Environmental Conservation (DEC) found bats in Hailes Cave in Albany County, NY with an unusual white fungus on their noses and mouths—dubbing the ailment “white nose syndrome.”

It is believed that humans first transported the fungus from a cave in Europe or Asia; it has also been suggested that WNS was brought to the US by a live, infected bat that was unintentionally transported across the Atlantic, but the likelihood that the bat would survive is low. Bats are the primary vector for spreading WNS as they hibernate in close quarters making transmission easy.

Research also shows that the fungus responsible for causing WNS in bats can grow in caves absent of bats. This makes the removal of the fungus from caves more difficult and aids in the spread and reintroduction of Pd, as bats enter infested caves may pick up spores.


WBS causes infected bats to become dehydrated and reduces their ability to maintain body temperature. WNS causes infected bats to exhibit unusual behavior—as the WNS fungus disrupts bats’ physiological processes causing hibernating bats to awaken before spring. This disruption causes infected bats to deplete their stored fat reserves during winter months, when food sources are scarce. Infected bats either starve to death or fly out of their hibernation sites, exposing them to predation and harsh winter elements. Based on laboratory trials, mortality caused by WNS occurs approximately 70-120 days after infection (Reeder, 2012).

Biologists and partners from the U.S. fish and Wildlife Service estimate that 5.7-6.7 million bats have now died from WNS, and they expect the disease to continue to spread. Since its original discovery, WNS has spread to at least seventeen states ranging from Maine to Tennessee as well as four Canadian provinces; it has impacted six species of bats that hibernate in NY : northern, little browns, big browns, tri-colored, Indiana, and eastern small-footed bats.

Bats are a major predator of defoliating forest and agricultural insects, and are important to forest health. Bats have been valued at $23 billion/year in “ecological benefits” (natural services such as pest control and pollination) for the agricultural industry.  WNS, is capable of reducing bat populations, which reduces the ability of bats to provide the ‘natural services’ that help maintain balance within entire ecosystems.


Confirmation of WNS requires the examination of suspected host tissue (histopathologic examination). Identifying signs of WNS affected bats include white fungal filaments located on the muzzle and wings; fungus on bat wings appears opaque and white, with a tacky film of varying density. Fungi are not always visible on bats with WNS, as the fungus is commonly lost when bats become active. Below are a series of photos of Pseudogymnoascus destructans spores (the fungi that causes WNS).

wns fungi


Below are two photos of bats infected with WNS.

wns on wings wns under light          The Black light reveals the fungal infection as bright orange splotches.


There are two known biological control agents for WNS; one is found living on bats while the other lives in soil.

Research lead by Joseph Hoyt at the University of California Santa Cruz show that naturally occurring bacteria, or probiotics (beneficial bacteria), have been found on bats and can inhibit the growth of Pd. Established probiotics can influence disease outcomes in individuals as well as whole bat populations and have the potential to provide a long-lasting solution for managing WNS, and unlike chemical fungicides, probiotics have the capacity to coevolve with the fungal pathogen associated with WNS.

Other research with U.S Forest Service and Chris Cornelison with Georgia State University shows that native soil bacteria called Rhodococcus rhodochrous can produce natural volatiles that inhibit the growth of Pd.  On May 20th, 2015 in Hannibal, MO, bats that had been successfully treated for WNS using R. rhodochrous. The data from this field experiment is being analyzed.

What Can You Do?

When entering a cave follow decontamination procedures and don’t venture into caves that are closed to prevent the spread of WNS. Protocol can be viewed at: www.whitenosesyndrome.org

Build a bat house:

Properly constructed and placed bat boxes could also help some infected bats that manage to survive the winter get off to a better start in the spring breeding season. Bat boxes provide an alternative location to trees or building for bats to have offspring. You can learn to make your own bat box at the following link:


bat house


Photo Credits: 

Title photo: N. Heaslip (http://wdfw.wa.gov/).  Pd spores photos: Kyle Gabriel and Dr. Robert Simmons, Georgia state University. Bat wings infected with WNS photo: U.S. Fish and Wildlife Service Southeastern Region, (flicker.com). Photo of WNS infected bat wing under black light: Greg Turner, Pennsylvania Game Commission. Bat house photo: compliments of (batstor.org).


Balmer, Jennifer. “White-nose Syndrome Has Almost Completely Wiped out Some North American Bat Colonies.” Science (2015): n. pag. US Fish & Wildlife Service, 17 Jan. 2012. Web. 13 July 2015 <www.whitenosesyndrome.org/sites/default/files/files/wns_mortality_2012_nr_final_0.pdf>.

Fang, Janet. “Can Bacteria Help Save Bats From a Deadly Fungus?”IFLScience. IFL Science, 24 June 2015. Web. 13 July 2015. <www.iflscience.com/plants-and-animals/can-bacteria-help-save-bats-deadly-fungus>.

Hoyt, Joseph R., Tina L. Cheng, Kate E. Langwig, Mallory M. Hee, Winifred F. Frick, and A. Marm Kilpatrick. “Bacteria Isolated from Bats Inhibit the Growth of Pseudogymnoascus Destructans, the Causative Agent of White-Nose Syndrome.” PLoS ONE. Public Library of Science, 8 Apr. 2015. Web. 13 July 2015. <www.ncbi.nlm.nih.gov/pmc/articles/PMC4390377/#pone.0121329.ref022>.

Lee, Jane J. “Killer Fungus That’s Devastating Bats May Have Met Its Match.” National Geographic. National Geographic Society, 27 May 2015. Web. 13 July 2015. <http://news.nationalgeographic.com/2015/05/150527-bats-white-nose-syndrome-treatment-conservation-animals-science/>.

Reeder DM, Frank CL, Turner GG, Meteyer CU, Kurta A, et al. (2012) Frequent arousal from hibernation linked to severity of infection and mortality in bats with white-nose syndrome. PLoS One 7: e38920 doi: 10.1371/journal.pone.0038920

Jenna Kerwin and Carl Herzog. “Bats on the Brink White Nose Disease Takes a Toll on New York’s Bats.” Bats on the Brink. The Conservationist, 2012. Web. 13 July 2015. <www.dec.ny.gov/pubs/79994.html>.

J Vet Diagn Invest 21:411–414 (200, Carol Uphoff Meteyer,1 Elizabeth L. Buckles, David S. Blehert, Alan C. Hicks, D. Earl Green, Valerie Shearn-Bochsler, Nancy J. Thomas, Andrea Gargas, Melissa J. Behr. “Histopathologic Criteria to Confirm White-nose Syndrome in Bats.” J Vet Diagn Invest 21:411–414 (2009) Histopathologic Criteria to Confirm White-nose Syndrome in Bats (2009): n. pag. 2009. Web. 13 July 2015. <www.whitenosesyndrome.org/sites/default/files/resource/wns-histopathologypaperbycmeteyer2009.pdf>.


Vanderwolf, Karen. “Fungus That Causes WNS Can Grow In The Absence Of Bats.” Canadian Wildlife Federation Blog. Endangered Species, Flora & Fauna3, 3 Feb. 2014. Web. 13 July 2015. <blog.cwf-fcf.org/?tag=pseudogymnoascus-destructans>.

Vanderwolf, Karen. “We’re Learning More About The Fungus That Causes White-nose Syndrome!” Canadian Wildlife Federation Blog. Endangered Species, Flora & Fauna3, 25 Aug. 2014. Web. 13 July 2015. <blog.cwf-fcf.org/?tag=pseudogymnoascus-destructans>.

“White-nose Syndrome Threatens New York’s Bats.” White-nose Syndrome. NYDEC, 2015. Web. 13 July 2015. <www.dec.ny.gov/animals/45088.html>.




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