The number of bats in Pennsylvania has dramatically dropped over the years, but work is being done in mines and railroad tunnels to help these important flying mammals recover.
With Halloween around the corner and October being Bat Appreciation Month, experts are reminding people about why these small creatures of the night are an important part of our lives.
Gregory Turner of the Pennsylvania Game Commission, and Joseph Johnson of the University of Cincinnati have worked in some old mines in Pennsylvania to improve bat habitat.
Johnson likes to share with people about how amazing bats are in wildlife.
“They are the only flying mammal. And if that is not amazing enough, they choose to fly at night,” he said. “If it’s not cool enough that they have one superpower, they have multiple. They can echo locate.
“I just try to get people to appreciate the wonder of bats and try to get people to understand the value of bats. Not just in terms of the insects that they eat and the economic value of the insects they eat, but just the quality of life that we all experience when we have a rich natural heritage.”
Turner, state mammologist for the Game Commission, agrees bats are special creatures.
“There’s a whole slew of nice benefits from bats. Most of the bats in the northeastern part of the country, all of them in Pennsylvania, are insectivores, meaning that they eat insects,” he said. “And a good number of these insects, the moths for example, lay eggs that their larvae grow in the soil and destroy the roots of our crops.
“They (bats) save farmers about $74 an acre in pesticides and that equates to hundreds of millions of dollars in crop damage that is saved by bats in Pennsylvania alone. And, of course, that’s a lot less chemicals being spread on our food that we eat, which helps our health.”
Bats eat mosquitoes which spread equine encephalitis and can carry West Nile Virus which impacts grouse and other birds.
More: New state parks coming to York, Chester, Wyoming counties
“Just the mosquito aspect alone, they are helping to keep pests down that are spreading diseases for us,” Turner said.
Other benefits of bats are found in health research for anti-coagulants and the military with radar tracking.
“They are just fascinating animals all around,” Turner said. “They provide tons of benefits financially, ecologically to us. They pollinate all sorts of plants that produce food for us.”
For those who enjoy tequila and margaritas, he said bats are the only pollinator of the agave plant.
“Pretty much anybody you can think of. Anybody who likes to be outdoors and is bothered by mosquitoes or appreciates cheaper food or cleaner, less pesticides in the environment, there’s all sorts of ways that bats are benefitting us,” Turner said.
White-Nose Syndrome
White-Nose Syndrome (WNS), a fungal disease that kills bats, was first detected in Pennsylvania over the 2008-09 winter. By 2012, it was statewide.
The bat population in Pennsylvania, Turner estimates, has dwindled from more than 10 million to tens of thousands of bats.
“It’s already statewide, I think it’s here to stay,” Turner said about WNS. “Most wildlife diseases are that way.
“It’s in all our of hibernation sites. It’s just always going to be there. The bats need to have time to develop some resistance. If we look toward Europe, we see that they still get it over there and we know it’s been there for a long time, at least a century, probably many centuries. The bat species are there, albeit in lower numbers but seemingly doing fairly well, fairly stable at this point. I think that points to where we are.”
Turner and Johnson have been working with several colleagues on projects where they have been cooling existing man-made hibernation areas like mine shafts in different parts of the state. With the right temperatures, bats will not wake up as often during their hibernation months and not lose as much of their energy reserves.
“I would like to extend gratitude to the U.S. Fish and Wildlife Service and the Bats for the Future Fund for funding a bunch of our scientific work,” Turner said.
In addition to working with Mike Scafini in the Game Commission, Turner also collaborates with Brent Sewall of Temple University, and Barrie Overton, a White-Nose Syndrome expert at the Commonwealth University of Pennsylvania.
“At the sites that we’ve cooled, we’ve had some success, which is good. It’s a drop in the bucket compared to the larger problem out there,” Turner said.
“If there’s a mine out there with a whole bunch of survivors, and it’s really cold, it’s possible that a decent number of our surviving Indiana bats are going into those sites. We might have a couple other sites out there that are harboring more Indiana bats than what we know of and that would seem likely based off of the fact that we have 100 to 150 females alone at a maternity colony. So, there’s hope there.”
How to cool a mine
They don’t work on caves as they don’t want to impact the natural environment.
“We’re not trying to manipulate natural cave environments that are pristine, natural ecosystems,” he said.
In the man-made shafts like mines and tunnels, the crews manipulate and create openings to give the mine shafts the most ideal temperatures for bats, 38 to 42 degrees Farhenheit in the wintertime.
“Every site is different and unique. What it really involves, boiled down, is trying to find a way to get the coldest air to pool in the bottom of the mine, the lowest elevation,” Turner said.
Results of their work
They have seen some success with attracting more bats.
“At our original site, the first we ever attempted to do this at, is a site that we’ve had the best success at,” he said. “We had only three bats remaining in that site when we manipulated it. We had two little brown bats and one tri-colored bat and that was in the summer of 2015 when we opened that up and got the cold air to go in and we now, we have over 800 bats in there.
“After that first winter, we had seven bats in there. The next winter we had 28 bats. Each of these bats only have one pup per year. So even if all those bats were females, going from 7 to 28 is biologically not possible. That indicates clearly that we are drawing in survivors from other locations,” Turner said. “This is not absolute recovery. We are providing something that the survivors are seeking.”
Now nine years after his first manipulated mine site, Turner said they are working to create more sites that can provide a colder winter environment.
“It’s prudent to replicate that success at some other sites,” he said.
In addition to cooling the mines, Johnson said the spray treatments being done by Brent Sewall of Temple University has been slowing the growth of the WNS fungus. The spray, polyethylene glycol 8000, he said is something that’s safe around humans.
“They spray it on the walls and what it does, it slows the growth of the fungus, and we presume it lessens the stress on the bats during winter,” Johnson said.
“Both of these management strategies are pretty intensive,” Johnson said about modifying the environments. “What we’ve done is added tools to our toolbox and we can selectively apply each one of those tools in different areas where they might be most appropriate.”
Johnson agrees with Turner about the ongoing need for bat habitat work.
“I think it’s important to note, a lot of the species that we talk about when we discuss White-Nose Syndrome, such as the little brown bat, tri-colored bat and the northern long-eared bat, their populations are really quite low and that is something that should be a concern because those populations recover very slowly, they only have one young per year at most,” Johnson said.
“Thanks really to the tireless work of a lot of researchers and the agency biologists in Pennsylvania, they’ve really given those species their best opportunities to recover through habitat management, through research and all the endeavors that they do at the various university levels as well as at the Pennsylvania Game Commission.
“I’m not going to say the future is bright and rosy, because it’s going to be outside our lifetimes before it’s bright and rosy for the species that recover so slowly, but I’m pleasantly surprised at some of the progress that has been made, especially with the little brown bat in Pennsylvania.”
Welcoming bats to your area
Johnson encourages people to welcome bats in their areas by placing bat box houses on tall posts in partial shaded areas on their property. Bats prefer the boxes being placed posts instead of on trees or buildings. Being fixed on a posts allows the bats more area to enter and exit the box.
“There’s a way to share your property that’s good for bats and good for people and a lot of times that’s providing them with artificial roosts,” he said. The Game Commission’s website offers information about bat houses and where to best place them.
He likes to address some of the negative perceptions people have about bats.
“Bats are not likely to get stuck in your hair, bats are not likely to give you rabies, bats are not dirty animals. Bats have more in common with the people than we think,” he said.
Bats, like little brown bats, can live several decades in the wild.
“They only can have one young per year, the little brown bat, and they put a lot of effort into raising that one young. They have really strong social bonds. They form these large social groups in the summer, females do where they raise their young together,” he said. “Like so many things in life, we have a negative perception of something because we don’t understand that. But the closer we look, the more relatable they are.”
Brian Whipkey is the outdoors columnist for USA TODAY Network sites in Pennsylvania. Contact him at [email protected] and sign up for our weekly Go Outdoors PA newsletter email on this website’s homepage under your login name. Follow him on Facebook @whipkeyoutdoors.
This article originally appeared on Erie Times-News: How many bats are there in Pennsylvania?
