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Fungus forces bats to near extinction

by Molly Cochran

Little brown bats could be nonexistent in as little as ten years, Mike Gannon, a biology professor at Penn State Altoona, said.

Cave dwelling bats have seen a rapid decline in eastern North America due to a disease known as White Nose Syndrome, or WNS. Between 5.7 and 6.7 million bats in eastern North America have died because of WNS, according to

WNS infects bats that are in hibernation. The term “white nose” developed because diseased bats have white muzzles and other white body parts.
The syndrome causes the bats to wake during hibernation and act abnormally, which includes unusual flying. Cave dwelling bats rely on hibernation during winter for survival.

Geomyces destructans is the fungus that is associated with White Nose Syndrome. According to, the fungus is believed to be fatal because of skin infection.

Doug Wentzel, program director and naturalist at Shaver’s Creek, said that the fungus is spread from bat to bat. The fungus spreads in caves during the winter months. The fungus can only grow in caves that have very low temperatures.

“It is pretty dire. The mortality rate in some caves is 100 percent,” Wentzel said.

Because of bats’ low reproduction rate, Wentzel thinks that brown bats could be an endangered species in the years to come because of WNS.

The reproduction rate for female bats is also very low. Females only give birth to one pup every year.

Shaver’s Creek has not had any reported cases of WNS, but Wentzel said that they have had bats that have been acting strangely.

Also, there has been a significant decrease of bats in their bat boxes.

According to Wentzel, during the summer of 2007 there were 1500 bats in Shaver’s Creek bat boxes. Last summer, however, there were only 69 bats in the bat boxes.
Wentzel said he believes WNS is to blame for this significant decline in bats.

Gannon said that the disease affects only bats. Humans that have hiked in caves can carry the disease on their hiking equipment, but as far as we know, humans can’t contract the disease.

Gannon said that the disease was believed to have originated in Europe and brought over to the U.S. by humans. The first reports of WNS were in New York in 2005. Since the reports in 2005, the disease has spread as far as Oklahoma.

Bats in Europe have not been getting sick from WNS, so Gannon said he thinks that the bats have adapted to the disease. However, but bats in the U.S. are dying off.

“It is mostly always fatal,” he said.

Cal Butchkoski, Supervising Biologist for the Mammal Section of Wildlife Diversity Division of the PA Game Commission, said that there has been an estimated several hundred cases of WNS in bats across Pa.

According to Butchkoski, the majority of caves throughout Pa. are infected with WNS.

Even though a significant amount of bats are dying, Gannon said, there is no way to prevent the disease, and the funding for research has dried up.

However, according to, “Since 2008, the United States Fish and Wildlife Services has spent approximately $7.9 million in research and state capacity support.”

Although the majority of bats that contract WNS die, a recent finding by the U.S. Geological Survey and collaborators at National Institutes of Health suggests that bats recovering from WNS have immune reconstitution inflammatory syndrome, or IRIS.

IRIS is usually found in AIDS patients. If this were to be proven, it would be the first time IRIS was found naturally.

In addition to furthering research, bats also help with agriculture.

A little brown bat during the active season eats about four to eight insects a night. The economic value of bats for agriculture is estimated to be around $22.9 billion per year, according to “Economic Importance of Bats in Agriculture.”

Gannon said that if the bat population is no more, the U.S. would have to spend more money on insect control because bats are a natural remedy to insect control.
Even with a significant decline in bats and data to support that WNS is to blame, it may be some time before we see them on the endangered species list.

Gannon doesn’t expect them to be put on the endangered species list anytime soon, because it would make construction more difficult. Companies would have to check for bats before tearing down a building.

Butchkoski said that there is enough data that supports that bats should be on the endangered species list, but that there has been some confusion between the state and federal level as to whether bats should be an endangered species or not.

According to Gannon, the PA Game Commission has been informed with the data they need to place cave dwelling bats on the endangered species list, but the Game Commission said no.

Gannon said that the PA Game Commission reported that they don’t have enough data to place them on the list.

“One question to ask is, why is the government not acting?” he said.

Dr. Radut | feed_item