The concern has been that as more and more wind turbines are placed, if we don't do something to reduce the mortality, then we will see millions of bats potentially being killed and eventually that will have major population impacts on those bat species that are most vulnerable.
Energy generation has often been at odds with the natural environment, the process of extracting coal or oil is fairly disruptive. The leftover byproducts of nuclear fission are a long term concern. Clean energy options would seemingly not have these issues, yet, some other issues do arise. This is random acts of knowledge presented by Heartland Community College, I'm your host, Steve fast, wind energy is considered a clean option for the generation of electricity. But with any developing technology, there are unexpected consequences. In the case of wind turbines, there is a concern that rapidly moving blades are killing too many bats. But there may be a solution. Today's experts discuss a research project aimed at keeping wind farms from damaging a key part of prairie ecosystems.
I'm Janet Beech Davis, I'm the Associate Director for the science labs here at Heartland, which means I help take care of anything that has to do with any science class here on campus.
So Heartland Community College has a 1.65 megawatt industrial wind turbine that generates over 40% of the college's power. In addition to the power generation, though the turbine being a single unit instead of part of a farm presents some unique opportunities for research.
We're doing a research study on the turbine, our turbine has special software on it that we have installed just this season, to where when the wind is below five meters per second, for more than two minutes. So when the wind calms down to below five meters per second, the turbine blades feather out so that they don't turn. And we've done that deliberately now. Other ones sometimes they're down for maintenance, if like if you look at the wind farm across the road, sometimes they're not for maintenance, sometimes the wind is just not blowing enough to get it going. So there's a lot of reasons why they might not be turning hours will not turn between half an hour before sunset, and half an hour after sunrise. If the wind is below five meters per second, our turbine does not turn.
Why is that? Why don't we want it to turn during that time?
Well, that's that migration time. And this time of year is the bat migration. And they're all moving south. And we're doing a study on our turbine for about mortality. So we're trying to see how many bats get killed by turbines, we have about three years worth of data to yours was a good data. And then we installed the software this year. And so now we're collecting data. And because bats tend to fly when there is a breeze and when the wind is blowing, but not blowing hard. Nobody wants to fly in a hard wind, and they fly at night. So if we have our turbine, if it's turned off during migration time, then the idea is we're gonna kill fewer bats. So that's what the software is supposed to do. And that's what we're studying. Is it does it kill for your bats?
Well, how are we tracking the bats we kill? Do they go down to the to the bottom of the turbine and collect them? How does do
that's my job between August 1 and October 31. I walk out there every day I do Monday through Friday and Saturday and Sunday. Angelo Capitola from ISU who's helping us with the study. He does the weekend so that I don't have to come in every day. We go out and we walk around the turbine, we have a plan where we I walk around the turbine six times in concentric circles, so that I can see everything out there. And we flag and bag, dead bats or anything else that gets killed by the turbine.
This raises a number of questions. The first is how do you know that the bats are killed by the turbine? Maybe it was just natural causes? where it happened. If that's
just where it happens, they get caught up in the study. We assume turbine they might have just run into the turbine. So turning or not, maybe they were feeling depressed and want to you know, just wanted to end it all. They just couldn't, couldn't take another day in their bat lives. I don't know. But if they're around the turbine and they're dead, we count them.
What else do you find that gets caught up in the turbine?
We do find it the occasional bird we find. I don't know if the turbine kills them. But sometimes I'll find a bat and then right next to it, I'll find a cicada. So he was chasing this Qaeda. Maybe it was in his mouth. And when he got hit by the blades, he dropped it f and dragon flies right next to him. So sometimes I find whatever it was it was occupying their attention so that they did not give proper attention to the turbine.
Why are bats drawn to the turbine you
mentioned that's more than bird Birds, yeah, they're not drawn to the turbine, they just happened to be there just happened to be there. And birds are better at avoiding the blades and birds generally do not fly at night. Birds roost at night. So bats are out flying at night. And so that's when they hit the turbine. We know bats migrate, we don't know why they pick one day to migrate and not the other day to migrate other than the wins
when you started counting bats, before this implementation of the software to adjust the turbine, and then after what's been your count of mortality for the bats, has it changed,
it has changed last year before we had the software and we had 14 bats and three birds last year, that is actually much lower than what most people get on turbines, we're really lucky that we only have one turbine. So it's a really unique opportunity that we have an industrial sized turbine. And we only have one, when you're in a wind farm, the turbines affect each other. And so if you get bats migrating through, or birds migrating through, they might miss one turbine, but they might hit another one. So it's more dynamic inside a wind farm than it isn't just a standalone turbine. So we have a really unique opportunity to study the effects of one turbine. So last year, we hit 14 bats and three birds this year, so far, we're not done yet, we still have a couple more weeks to go. We've gotten seven bats and to birds. So that's a significant decrease. So far, the recommendations are that if you have the software running and set the way we do, so that turns the blades at five meters per second, you can expect a 50% mortality decline. And that's about where we are actually better than that.
What will we be doing with all this data? When we gather? Is it just for the operation of our turbine? Or does it go to some other purpose?
No. Dr. Kip Rolla at ISU is going to be writing up a paper on this, and publishing it. And so other people will benefit from all of this research that we've been doing.
So a lot of people might be hearing this and they think, Well, I guess it's good that they're studying what the effects of the turbine are on bats. But why do we care about bats? They're scary. They have rabies, they turn into Dracula, there's a reason we don't want to be wiping out the bat population. What is it,
people are a little bit concerned about things like West Nile virus, and Zika virus. And the vector for all of those are mosquitoes. And bats eat 1000s of mosquitoes. So if you want to get rid of mosquitoes and other bugs, you go for bats. Bats are incredible bug eaters, that's their job. So if we lose our bats, then our insect population is there's going to be nothing controlling it anymore. So we need our bats and they're cute. i People don't think they're cute, they're cute, and, and rabies and bats is you're going to get more of a chance of getting rabies in dogs and cats than your rabies and bats. And when was the last time you saw a rabid dog. So people are just scared because they're wild animals, they will not get caught in your hair. They are not blind, they see perfectly fine. They don't want really want anything to do with you. They will like to nest in your house, if you have a hole, they will be perfectly happy to come and sleep there. But otherwise, they're not bad to have. And they're good to have around and they help control our insects and bats right now, because of humans, bats have been on a decline. There's a white nose virus affecting the bat population severely, especially in southern Illinois, where the caves are. And people that go into caves, they get it on their shoes, and they take this virus, or it's a fungus from one cave to another and affect the bat population. So a lot of caves in Southern Illinois have been closed off to humans to try to stop the spread of this fungus. And so the bat population has already been impacted by humans just walking into caves just by people going into the Batcave just walking into the cave, because caves are cool. And if you then you walk into another cave, and you have spread this fungus, we want to know what other impacts we're having. And so far from what we've shown, we are way below the typical mortality rate or the predicted mortality rate, which is really good. And we were very, very happy to see how many fewer bats we're getting this year than we got last year. And then we're getting ready to share it with the world. So we're doing real science out there every day. As I'm walking around the turbine, getting my steps in every morning. We're getting real science.
What do you do with the bats after you've counted and bagged them?
I give them to Dr. Cap Rella and he takes him over to ISU and he makes sure that I have the right species. He's the real expert when it comes to bats. and that kind of thing. So I can tell one from another. Now, Eastern Red bats are a little ginger bats, they're little red haired bats, and they're really cute. I can tell those from the other ones. But if I'm not sure I just say I've got one and I'm not sure what it is. So he identifies them for me. And then he adds them to his collection. He has quite the collection of animals over there that they do research on.
So you just connect with him and you give him a bag full of bats.
I do. I call him as a got some bats. And he's like, I'll be right over. It comes over and with his little cooler and he gets the bats.
Well, Jana, thanks for talking to us. Sure.
My name is Angelo Capra. I'm an associate professor of Vertebrate Zoology at Illinois State University. And I've been interested in the impact of wind turbines on that populations for some time. I've had students do some research on that at the university. And I also was interested in partnering with Heartland particularly partnering with Janet Beech Davis at Heartland to do a study of the impact of the single wind turbine that was installed at Heartland a few years ago.
Now, were you interested in bats before this particular focus of the study?
I've always liked bats. Although my main interest has been in birds, I had been involved as a graduate student and helping out with some bats studies in the past. As a conservation biologist, I teach conservation biology courses at ISU, we know that bats as a group are undergoing precipitous declines, very alarming declines for a host of reasons. And because of their important role in ecosystems for humans, natural pest control, there's a lot of attention being given to the plight of bats.
So how long is the study been going on? The study,
we are now in the third year of the study, the first two years was to get a baseline understanding of the numbers of bats that are being killed by the turbine, and also divide them up into species to the extent that we could and age classes, sex classes, that kind of thing. And then this year, is the really exciting part in that we're seeing if a plan implemented by Heartland to reduce bat mortality is truly going to work number one, and if so, at what rate? Will we see a reduction in the mortality of bats at the turbine?
So how much more data do you have to collect to start to create some findings in that way?
That's a good question. We're not sure how much more we'll need. We'll we're still in the midst of collecting data from this fall. So our objective has been sampling August to October, which is the primary period of fall migration of those bats that migrate. And we will need to really take a hard look at the data at the end of the season, to be sure, already, the results are encouraging. And that it looks like there has been a significant decline in the number of bats killed by the turbine based on the procedures implemented by Heartland. And so we will have to take a hard look and see if we can support that statistically in terms of the study designed to see if we want to continue next year or not. But I'm cautiously optimistic that we do have evidence that the procedures are working. So
let's talk a little bit about why those procedures are important. Some people might not understand the impact that wind turbines could potentially have on bat populations and why an impact on bat populations could be an issue.
It's estimated that across North America, about 600,000 bats per year are being killed by wind turbines. And what happens is the bats obviously don't understand that there's a large structure right in front of them that's turning at a high rate. When they migrate, they typically are not echolocating. So they wouldn't detect it at all. And it just so happens that a lot of these turbines are at about the elevation altitude that bats move through as they're migrating, even if they are echolocating. These turbine blades, the tips are turning at an incredible rate of speed. And they just can't counteract that. If they get hit. It's really blunt force trauma that causes the problem, they just get whacked by the blades. The concern has been that as more and more wind turbines are, are placed, if we don't do something to reduce the mortality, then we will see millions of bats potentially being killed and eventually that will have major population impacts on those bat species that are most vulnerable.
I would imagine that if millions of bats are killed, those bats eat more than millions of things that we probably don't want to not be controlled in the ecosystem. Right?
Certainly. Yeah. I mean, we're seeing other factors that are affecting non migratory bat species such as white nose syndrome, which is a fungal infection that is causing collapse of other bat species. The three minute Torrey tree bats that we're most concerned about here in Illinois are the eastern red bat, the silver haired bat and the hoary bat. And those are the three that seem to be particularly affected by wind turbines.
Why bats more than birds? From what I understand, it's more of a concern for bats and birds. But the birds just have better vision, they can avoid the turbine, do they not fly at the same altitude when they're migrating? Why is it more of a concern for bats numbers,
you put your finger on it, they don't they fly to a higher altitude and bats. And typically, and the initial concern, of course, were birds, there were some early sightings of wind turbines that were causing problems for actually raptorial species as opposed to migrating species. And so the initial requirements were to do regular surveys at the base of wind turbines for bird deaths to see if the turbines had been cited in places away from the likelihood of killing birds. And then much to everyone's surprise, because we don't know a lot about bat migration, instead of birds that were finding dead bats. And that was actually a very surprising finding, when that occurred, and turns out to be fairly universal. Apparently, bats do migrate in these broad fronts, across open cornfields and everything else. And that was just not known because we know so little about that migration.
Are you learning things about that migration through this study
was certainly learning that bats are migrating and are fairly broad front, what we weren't sure is, if a single turbine at the edge of an urban center would be intercepting this bat migration in the way that wind farms which are set out as clusters in rural areas were intersecting bat. So that was kind of interesting. So really, there haven't been many studies of single turbines and single turbines in an urban area. So that makes this study very interesting, as a way of comparing to the large scale wind farms and in rural areas and see if we're seeing comparable levels of per turbine mortality.
The goal as I understand it, is to see how the software which which basically tracks good times to turn the turbine down or off, will help find the sweet spot where the the bats are not going to get killed, is that same methodology then applicable to the farms where you see 1015 turbines, which I would imagine present a bigger problem for the bats.
All of these bat deaths are cumulative. So let's say basically, the average number of bat deaths per turbine are 15 a year, but or at least a 15 per migration in the fall. But obviously, as you start summing across up incredible numbers of turbines that really starts adding up. And when you also have on top of that habitat loss and other factors that are affecting that populations, every little bit is a problem in terms of causing these issues. And every little bit you can do to reduce that mortality can help these populations. What we've learned is that through the industry itself doing these studies initially, is that if you change the cut in speed, the point at which the turbine starts turning to intercept when and set it at a slightly higher level than the actual wind is blowing. Now, that is, instead of just a very light breeze, triggering the turbines to turn, set it at a higher speed, basically five meters per second, then you will reduce bat mortality, because apparently, bats do not like to move migratory early in higher wind speeds. And so the idea is that if you wait until wind speed is above the threshold that bats like to use, then the likelihood of bats encountering a turning turbine is going to be lower. And that's what the program the software does is it basically during the migratory season changes the cut in speed of the turbine so that it waits until the wind gets above a certain level that presumably, the bats will no longer use to allow those to cut in. And again, that's done just during the night when the bats are moving.
And the turbines only generate power once the wind gets a little bit higher.
No, they are generating. And that's why there's been some resistance from the wind industry and implementing the software at certain threshold levels. So they've actually implemented at about three meters per second, which is estimated to only be about 30% reduction in bat mortality, whereas five meters per second, we think will get us up to 50%. And maybe more. That's also something we're interested in seeing for the specific turbine is because we're using the five meter per second, which the Illinois Department of Natural Resources would prefer but cannot require. We want to see if the reduction in bat mortality from the baseline that we established earlier is around 50% or so.
Have there been any complications and gathering your bats and your data in the study when you're starting early on.
When we initially started we had a little Bit of a complication that there was reticence to actually clear a substantial amount of area around the turbine blades that we could find them at. Initially, there was cropping done right up to the base of the turbine, and you just can't find dead bats in the middle of corn or soybean fields, it just doesn't work and even after they're harvested, is very hard to find. And so once we had an agreement from Heartland, that they would convert a significant area to mowed grass that made things so much easier. A study that was done before we started attempted to do this on top of the crop fields, but it was just not possible.
Janet goes out and collects the bats every day. And then the day she can't do it, you go out and do it. What happens then, how does that process go from there,
we basically are taking each bat and cataloging as a specimen. So I'm also a curator of vertebrate collections at Illinois State University. So it becomes part of our database. This allows us to do future studies on the individual bats themselves if there should be some interesting directions to follow. But basically, the basic data we want, of course, is the species of bat. From that we can tell the actual age and sex class of the bat as well. There are characters external characters you can use, we also record precisely where it was found and the circular footprint that we have to search, just as an interesting to see if there's any kind of attenuation of the likelihood of finding bat specimens as you get away from the center of the turbine or not. And so it's pretty basic in terms of that so far,
have you noticed any differences in the bats that you've collected Have there been more of one kind or another or more of more males and more females, anything that differentiates them?
So far, I've just looked at the species and I haven't yet assessed the age or sex classes That'll come later. We have all the specimens and freezers at ISU, so that will be something we'll want to do. In terms of the actual species, the three species eastern red bat, hoary bat and silver haired bat, they're still the ones that are showing up whether they are dramatically different in proportions from year to year. We haven't looked at that yet. But that will be something we'll look at once we have three years worth of specimens that we can sort of plow through and actually get some further data off of those.
So there's just a freezer somewhere over there at Illinois State that you just have a whole bunch of bats, I have
more than bats. I receive from the public roadkill and window kill birds and other potential specimens that are useful for our vertebrate collections, which we use in our research and teaching. I have all the necessary IDNR and Fish and Wildlife Service permits to to basically what we call salvage that is things that we find dead. And in essence, a Heartland is working under those permits that I have to be able to salvage these bats and make that part of the study.
Bats aren't the only thing you study. And this is not the only way that you study bats. Tell us about some of the other things that you've done outside of this study.
Well outside of the study right now I have a major study going on where I'm trying to find out the reptiles and amphibians that live within the Makena Valley watershed primarily focusing on McLean and Woodford counties, and particularly interested in the Parkland Foundation's nature preserves system, which is consists of about 3600 acres, as well as the other preserved lands such as come Laura Park and elsewhere. We are interested in knowing if the historic records of reptile amphibian presence if those species are still here, and if so how they're doing. And so I've been working with undergraduate students doing regular surveys trying to find which species of reptiles and amphibians still live in our area. These are challenging species to work with, because some of them are only visible or detectable for a very short period of time. Otherwise, they're often underground, whether hibernating or just living their regular life. And I've also relied on people sending me photographs of things that they found or roadkill that they found as a way of supplementing our direct work. And it's actually led to some interesting discoveries. We found some species we thought were long gone are actually still here. In a few cases, we've located new breeding colonies of salamanders and frogs. That's important because we want to protect those wetlands that have those colonies. We even had species that had never been recorded here before that probably were just missed in earlier survey work, because they're just secretive and hard to find.
What are some of the species that you found that we thought were gone?
The most important one is the state threatened species called the Kirtland snake. We thought that was completely gone from McClain County. And then some years ago, I actually received a photograph from a State Farm employee who sent me a photograph of his daughter holding a steak and just wondering what it was. And I'm always helping people to identify vertebrates that they find and my eyes sort of opened up wide and I said, Oh my gosh, if we discovered the Kirtland stay here in McLean County, and since then we found two other populations. Have that species here. So that's been very exciting, because that is a snake of special concern in the state that we want to make sure we don't lose it all together. And it's good to know that they're in at least three fairly secure populations in the county after all.
So other than the dead bats that you study, do you do any study on live bats out throughout Central Illinois?
No, I haven't done any live bat studies, except to the extent of doing some acoustic recording at some of the nature preserves, just to kind of see what's around those who certainly live. So I guess I am doing that. We're very interested in just getting again, baseline data as to what's using these nature preserves, because other bat species are showing symptoms of decline, as well. And we'd like to know where their strongholds are in terms of their summer breeding habitat.
You touched on this just a little bit earlier about the recommendations for the wind speeds in the turbines. Is there any regulation currently on these wind farms or an on these energy providers where they have to do any protections for the environment?
Yeah, it's it's not exactly set up the best way that we would like, essentially, in a state like Illinois, the only entity that can require the protection of bats is the county ID and are cannot Fish and Wildlife Service cannot. Some of the wind farm companies are some are more likely to do it voluntarily than others. But and the key is, as the county issue, special use permits any county in Illinois issue special use permits for wind farms, they can require that protective measures be part of the special use permit for the wind farms. To their credit, most wind farm companies do do a lot of survey work prior to determining where they're going to put the turbines as a way to at least avoid breeding areas of some of these sensitive bats. But the real problem is is that they can't do anything about the migratory bats in terms of siding because of this broad front that these things migrate under. For that they have to be willing to implement the software that will change the cutting speed of these turbine blades. And there is a loss of some revenue in doing that in the sense that, you know, if you're trying to get every little breeze, then if you're not allowing the turbines to turn, then you are going to lose some wind energy. And therefore there's been a little bit of tension between how protective are they willing to be voluntarily. That's where the county and the citizens of the county can make decisions as to whether they want to be protective of their bat fodder or not.
Well, Angela, thanks so much for talking to us. Sure. My mom, Angelo Kapur, Ella and Janet beach Davis are each engaged in the wind turbine bat study housed at Heartland Community College. If you enjoyed this podcast, check out some of our other topics including episodes on wind energy, solar science, and more. You can do so by subscribing on iTunes, Spotify or audiobook. Thanks for listening
