IT WAS AN UNSEASONABLY WARM DAY in late February. Hibernating squirrels were out looking for food. Birds, too, began to twitter on the telephone wires. I, zig-zagging along the narrow central Pennsylvanian country roads, was driving to meet up with Mike Scafini, an endangered mammal specialist for the Pennsylvania Game Commission, to talk about Pennsylvania’s vanishing bats.
Mike greeted me as soon as I walked through the automatic door of the Pennsylvania Game Commission building.
“How are you today?” he asked, while giving me a sturdy handshake.
Mike—a tall, slim, 30-some-year-old fella with a thick dark beard, short hair, and a pair of thin-wire glasses—is a wildlife biologist for the PA Game Commission. His job is to manage all non-game mammals, such as northern flying squirrels, woodrats, and of course, bats, across the Commonwealth of Pennsylvania.
The Game Commission compound itself is interesting. Sitting on the outskirts of the state capital, Harrisburg, the exterior resembles something between a DMV building and a middle school auditorium. The inside, however, is an eerily harmonious combination of a natural history museum, a country pub, and the visitor center of a national park: green carpet, wooden benches, deer heads mounted on the wall, various wildlife taxidermy staged in giant glass cabinets, a canoe in the center of the lobby, a TV showing animal videos on loop, and exhibitions displaying law enforcement officer uniforms.
“When people think of the Game Commission,” Mike told me, “they usually think of elk or deer or bear; but here [at the Game Commission], we are actually also in charge of small mammals that people don’t usually think of as Pennsylvania wildlife.”
“That’s why I am here today: to talk to you about bats,” I agreed that most people I know had little awareness of these small creatures in their local environment.
THERE ARE NINE SPECIES OF BATS found in Pennsylvania: little brown bat, big brown bat, eastern pipistrelle bat, northern long-eared bat, Indiana bat, eastern small-footed bat, silver-haired bat, eastern red bat, and hoary bat.
Among the nine species of bats, silver-haired, red, and hoary bats are migratory bats, meaning they—like some birds in North America—migrate to the south when winter approaches. The rest of the species are short-distance hibernating bats, meaning they don’t make long migratory trips when winter comes. Instead, they hibernate in Pennsylvania or in adjacent states.
The most common species in Pennsylvania nowadays, according to Mike, is the big brown bat. When a person sees a bat in Pennsylvania, it is most likely the big brown bat.
For states like Pennsylvania, which depend heavily on agriculture, bats are extremely important for the economy. Bats are the state’s primary night-flying predator of insects, protecting people and agriculture from pests. Some research shows that a single bat can forage as many as 500 insects in an hour, which equals 3,000 insects every night. A colony of 150 big brown bats, the most common bat species in Pennsylvania, can consume approximately 38,000 cucumber beetles, 16,000 June bugs, 19,000 stinkbugs, and 50,000 leafhoppers. And by devouring the adult beetles, bats can also prevent 18 million corn rootworms from hatching in a single summer.
“The Pennsylvania agriculture industry owes a lot to bats,” said Mike, while pointing at a figure from a 2011 study published in Science. The figure was captioned: “Estimated economic value of bats to Pennsylvania farmers…Bats can save farmers $74 per acre—and millions of dollars each year—by eating bugs that can ruin a harvest.”
THE DESTINY OF HIBERNATING BATS in Pennsylvania, like the destiny of their peers across the east side of North America, has become catastrophic, because of a newly discovered bat disease called White-nose Syndrome.
Since its first discovery in the U.S. in February 2006, White-nose Syndrome has spread rapidly across the eastern states and provinces of the United States and Canada, wiping out millions of hibernating bat population. The first sign of White-nose Syndrome in Pennsylvania was recorded around the winter of 2008, and since then, the population of hibernating bats in Pennsylvania has been dramatically declining.
“Of the six [hibernating] species [common in Pennsylvania],” Mike explained, “we have four of them close to, or approaching, ninety-nine percent [declination].”
“Jeez…ninety-nine percent?” I couldn’t believe what I had just heard.
“Yes…it’s a lot of bats.” Mike shook his head.
He went on to show me another figure from surveys he conducted by comparing the winter bat species population at the same sites in 2013 and 2016, which were before and after the White-nose Syndrome outbreak. In the graph, the populations of little brown, Indiana, northern long-eared, and tri-colored bats have declined almost one hundred percent.
“And the number of bats has not rebounded,” Mike added.
THE FUNGUS THAT CAUSES White-nose Syndrome in bats is called Pseudogymnoascus destructans, a cold-loving fungus that can infect and colonize the bats’ skin. This fungus is native to Europe but not to North America. Scientists have speculated that cavers who went to Europe for caving brought this fungus back and inoculated this invasive pathogen into the caves in New York State.
During hibernation, bats reduce their metabolic rate and lower their body temperature to save energy, which offers the opportunity for the fungus to live, grow, and reproduce. Bats infected with white-nose syndrome often have visible white fungal growth on their muzzles and wings (hence the name) and become irritated and dehydrated. As a result, they wake up and fly out more often during the cold winter while there are no insects to eat. And this has become the primary cause of death for bats infected with White-nose Syndrome.
Despite the fact that scientists have been working around the clock to find a cure for White-nose Syndrome in bats, the remedy still remains a mystery. Nevertheless, there is some hope in promising treatment, which was recently discovered by scientists and might be able to end this disease for bats.
“There is actually an interesting experiment that is worth mentioning,” Mike said. “It’s called PEG-8000.”
PEG stands for polyethylene glycol, and it is a class of chemical compounds that have a wide range of medical, chemical, biological, and industrial uses. PEG-8000 is one specific type of PEG that can cause microbes to think that they are deficient of water, thus tricking them into slowing growth. Plus, because PEG-8000 is non-toxic and chemically stable in fungi, it is considered as an ideal compound to stop White-nose Syndrome by hindering the growth of Pseudogymnoascus destructans—the fungus that causes White-nose Syndrome. Based on what Mike described, when scientists applied PEG-8000 to the wall of the roost, bats in the experiment were able to avoid picking up the Pseudogymnoascus destructans spores.
“This indicates PEG-8000 could be used as a roost cleaning application,” Mike explained. “And being that bats are creatures of habit—they go back to the same spots in a cave in the winter. If we can treat these spots where bats congregate, we may have something.”
THE SPREAD OF WHTE-NOSE SYNDROME can be caused by physical contact between healthy bats and infected bats, or by bats picking up the fungus from the surface of the cave where they hibernate. Human activities in the caves have exacerbated the spread the disease by introducing the fungus from one cave to another or by inadvertently carrying the fungus on shoes, clothing, or gear. (Just like the fungus is believed to have been introduced to North America to begin with.)
Therefore, Pennsylvania government agencies, such as the Game Commission, have strictly implemented the decontamination protocols released by the U.S. Fish and Wildlife Service to minimize their chance of spreading white-nose syndrome among bats when working in the field.
“We are working closely with the U.S. Fish and Wildlife Service, and one big step was the decontamination protocol that [the U.S. Fish and Wildlife Service] put out,” Mike explained.
Therefore, PA government agencies such as the PA Game Commission has also strictly implemented decontamination protocols released by the U.S. Fish and Wildlife Service to minimize their chance of spreading white-nose syndrome among bats when working in the field.
According to the newest (2016) version National White-Nose Syndrome Decontamination Protocol, individuals in contact with bats or going into the hibernacula of bats are recommended to decontaminate their gear—an effective way to prevent the spread of the spores of the fungus. These procedures are strictly followed by bat survey participants like Mike and many other scientists from the state government agencies.
In addition to the state level of protection, the Game Commission is also working closely with the caving community throughout Pennsylvania to raise their awareness of which caves people should go into and which they should avoid, as well as implementing the decontamination guidelines to the caving community.
“Most [caving] people don’t have any problems following the decontamination protocol,” Mike said. “Some caving groups are actually helping save the bats by helping conduct bat surveys.”
To survey the bat population, every winter, Mike, along with other bat scientists, often enter dozens of sites where bats are hibernating to count their population.
“[The caving groups] often count the bats while caving and report the data to us.” Mike went on. “Sometimes we even invite them to come into the cave and help us out for the survey.”
“Do you consider yourself a good caver?” I asked Mike.
“I’d say so.” He laughed.
WHILE HIBERNATING BATS have been suffering from white-nose syndrome, migratory bats are also not without threat. They are declining because of a different threat: wind farms.
According to Mike’s survey, a thirteen-turbine wind farm can estimably kill five hundred or more bats every summer. Mike spent part of his master’s work in biology on surveying the effects of wind turbines on migratory bats.
“Altogether—the wind farms for migratory bats and White-nose [Syndrome] for hibernating bats—are dramatically wiping out the PA bat population,” he added.
Mike’s concerns are important to consider as the United States is now one of the world’s leading producers of wind energy. Although wind energy is often considered “good” energy for us, it might not be as “good” for flying animals. With tens of thousands of wind turbines operating in the U.S. currently, and a great number planned to be constructed, the death of flying animals—not only bats, but also birds—has been increasing every year. According to the American Bird Conservancy, the annual mortality of birds caused by wind turbines was estimated to be as high as 573,000 in 2012. The U.S. Department of Energy predicts if the U.S. meets its goal of 35% of the electrical power from wind energy, up to five million birds would be killed annually by the wind turbines.
“SO, WHAT CAN WE DO to save bats when they visit our homes?” I asked, citing a problem many people may have encountered.
Bats in homes is something we see more as a problem in the summer, answered Mike. This is because bats form maternity colonies during the summer to raise their pups. In some cases, bats will try to set up a colony in people’s attic or other warm, dark places.
When a single bat invades a home, people can wait for the bat to land on something and then catching the bat by putting a Tupperware over it while slicing a piece of cardboard underneath the bat. The caught bat can be released onto a tree.
“If it is a larger number of bats,” Mike continued. “We have what is called NWCO, which is Nuisance Wildlife Control Operators…they know how to deal with bats.”
Additionally, people can practice “eviction and exclusion“, where they can put a one-way door in the opening of the house, so that bats can fly out the house but not back in. Once all the bats fly out, people can seal the openings. However, Mike also warned, this option won’t work if there are flight-less pups in the colony since “the adult bats will try whatever way to get back to the pups.”
Time flew by quickly, and, unwittingly, I had already spent hours talking with Mike. As I got ready to leave, I asked Mike what was the most unforgettable moment in his career as a bat scientist. His answer was the “good old days” when he could descend into a cave during a winter survey and see thousands and thousands of bats.
“That’s what it used to be like at the larger sites here in Pennsylvania.” He said while walking me out of the Game Commission building.
Driving on the same zig-zagging Pennsylvanian country road, I couldn’t help but ponder how after Mike showed me all the figures about bats that he had prepared for this interview, he said, “ Yup… everything is going down…”
1 Data from Wildlife Outreach Center, Penn State Extension. http://extension.psu.edu/natural-resources/wildlife/wildlife-nuisance-and-damage/bats/a-homeowners-guide-to-northeastern-bats-and-bat-problems
Realated—if you enjoy this article, you may also like these
Bat Conservation International: http://www.batcon.org
Bird-smart Wind Energy: Protecting Birds from Poorly-Sited Wind Turbines: https://abcbirds.org/program/wind-energy/
PennState Extension-Wildlife Nuisance and Damage-Bats: http://extension.psu.edu/natural-resources/wildlife/wildlife-nuisance-and-damage/bats/wildlife-damage-control-4-bats
Using a Novel Partitivirus in Pseudogymnoascus destructans to Understand the Epidemiology of White-Nose Syndrome: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5189944/
National White-Nose Syndrome Decontamination Protocol – Version 04.12.2016: https://www.whitenosesyndrome.org/sites/default/files/resource/national_wns_decon_protocol_04.12.2016.pdf