Though more than a little bit spooky, bats are crucial members of a wide range of ecosystems all around the globe, consuming insects, pollinating flowers, and dispersing seeds. In Northeastern Pennsylvania, it was once incredibly common to look up at the night sky and see their dark dance against the stars.

But in only a few years, several species of Pennsylvania bats have virtually disappeared, dropping from stable, healthy populations to endangered and in grave threat of extinction. It is estimated that greater than 90% of little brown bats, tri-colored bats, and northern long-eared bats have been lost over the last decade and a half. Why is this happening? The answer is White-nose Syndrome.

What is White-nose Syndrome?

White-nose Syndrome is a fungal disease that plagues many species of bats, some worse than others. It is caused by the fungus Pseudogymnoascus destructans (Pd). The disease gets its name from the white shade sometimes found on the noses of bats when the fungus is present. The fungus does not infect the bat internally, but instead, it attacks the bat’s skin. While this is irritating to begin with, the fungus is especially damaging because it causes bats to exit their hibernation. If you’ve ever noticed a bat flying around outside during the daytime in the winter, this bat was most likely afflicted with White-nose Syndrome. Over time, the bat becomes more active than it can sustain, burning up fat reserves and essentially starving to death.

White-nose Syndrome was first observed in New York in 2006, and rapidly began killing bats by 2007. It was first recorded in Pennsylvania in 2009, though it is likely that it arrived much earlier. Pennsylvania is not the only place dealing with the impacts of this disease, as White-nose Syndrome has been documented in thirty-five states, seven Canadian provinces, and has also been diagnosed in Europe and Asia.

White-nose Syndrome cannot affect humans; however, the fungus has a long lifespan, and can easily be inadvertently transported on clothing and shoes to other locations. This is particularly relevant to cave explorers, who are the most likely to come in contact with the fungus, as it often thrives in cold, damp, secluded environments, the same environments bats heavily prefer.

What can be done?

There is no known cure for White-nose Syndrome as of now, but scientists in Pennsylvania are exploring a diverse variety of ideas all aimed at curbing the spread of the disease as much as possible. One route to engaging with the problem head-on that is already being implemented is the use of polyethylene glycol (PEG). PEG is a common compound found in a wide array of everyday products, including toothpaste, shampoo, and makeup. Through testing, it has been found to kill Pd, the fungus that causes White-nose Syndrome. By utilizing spray techniques using this substance in areas where bats roost, they can be protected from the fungus, and infection can be prevented from the very start.

Another method involves manipulation of the overall habitat itself. Lowering the temperature of a roost habitat to a certain point reduces the viability of the fungus, while still allowing the bats to successfully hibernate. If the bats are not awoken over the winter, they will most likely survive to see the spring, when, even if infected, their immune systems will strengthen and they will have the energy to fight off the disease. Around the rest of the world, other methods to fight the fungus are being studied, including using UV-C light, probiotics, volatile organic compounds such as B-23 and decanal, and even a full vaccine that can be used to treat and inoculate the bats directly.

Still, however, there is much urgency to solve this issue as quickly as possible, and to save the species of bats most devastated by this outbreak before it is too late. If you believe you have observed bats in Pennsylvania displaying symptoms of White-nose Syndrome, please contact the Pennsylvania Game Commission immediately.