Nancy Solomon: It's the Brian Lehrer Show. I'm WNYC reporter Nancy Solomon filling in for Brian, who is out today. What could be more magical than catching a glimpse of a firefly on a summer night? Who doesn't have fond memories of chasing after these little critters who seem to come from another world and twinkle around your concerts in the park, or your suburban backyard, or walks home in the city, or around the campfire in the woods?
In recent years, it seems like this magic might be running out. According to estimates of local New York researchers, 14% of firefly species in North America are threatened with extinction. These researchers are now conducting a three-year project surveying the state's firefly population in hopes of preserving our remaining glowing friends. With us now to discuss their findings so far is science reporter Sarah Sloat. She's the author of the Gothamist piece, Fireflies May Disappear So New York Scientists Are Trying to Count How Many Are Left. Sarah, welcome to WNYC.
Sarah Sloat: Hello.
Nancy Solomon: Listeners, have you caught a glimpse of a firefly this summer or are you noticing a decline? Call us and share your experiences, 212-433-WNYC, 212-433-9692. If you can't get through on the phone, you can send a text to that number or tweet @BrianLehrer. Sarah, give us a better understanding of the decline of fireflies and what you were seeing. I gave that number 14%. Put that into perspective for us.
Sarah Sloat: Yes, so all over the world, anecdotal reports are coming up that fireflies seem to be fewer and fewer every summer. Every day people have started to notice this. That's important because that signals to scientists that, “Okay, we should probably look into this problem.” We're at early stages of really knowing what's going on, but a 2021 paper that looked at 132 species in North America, and I should say that there could be up to 225 species here, but that paper found that 14% are threatened with extinction.
This is likely a pretty low estimate because there wasn't enough data to assess for 53% of those species. There's a big need to gather this information and really be able to see what's going on so that there could be interventions.
Nancy Solomon: I can see the caller board is filling up. I'm going to be a stand-in for the New Jersey suburbanite. I have tons of fireflies in my backyard. Usually, they're only around in pretty much like June, in the beginning of the summer. I saw several the other night. We've had them all summer. I love to watch my dog chase around after them. Is it possible that they're actually thriving in some ecosystems, like a suburban backyard but not in others?
Sarah Sloat: Yes, so that's what scientists are starting to observe. This survey that I reported on, they just finished the first year of three years, but so far, results indicate that fireflies are thriving in more areas than others. I thought about looking into this story because I live in Brooklyn and I noticed that there were really few. I personally didn't see very many fireflies this year and I was like, "What is going on?" It seems to be that if you go to a dark park, yes, you'll find fireflies, but if you go to an area where there's more light pollution, you'll see far fewer.
Nancy Solomon: I'm sorry, I got a little lost. Are there fewer fireflies or you just don't see them because of the light pollution?
Sarah Sloat: Light pollution harms fireflies because they use their flashes to attract mates. If there's too much light pollution, they can't see each other and make that connection. It's starting to indicate that fireflies aren't finding each other in those special moments because of pressures like light pollution.
Nancy Solomon: Well, so it's not just the stars that we can't see anymore. It's having effects. I see. Your article focuses on researchers in New York State. Where exactly are they looking for the fireflies and what's the goal of the study?
Sarah Sloat: Right now, the researchers who are associated with the New York Natural Heritage Program, they're focused on state parks. As of now, they've gone to nine state parks. Then there's two more years to go. There's hopes that perhaps they can expand to other areas.
Nancy Solomon: You mentioned light pollution. Any ideas what else is causing the die off?
Sarah Sloat: Yes. The pressures on fireflies are similar to the pressures on insects overall, which are in decline. This includes habitat loss, in the case of fireflies, that's especially wetlands loss, light pollution, as I mentioned, pesticide use that can kill fireflies and their prey, along with climate change. Fireflies are especially affected by drought and severe weather changes.
Nancy Solomon: Let's take a couple of callers. We have Bob in Brooklyn on the line. Hi, Bob.
Bob: Hello. How are you? Thank you for taking my call. You're doing a great job, by the way. It may seem difficult from where you are, but from the listener standpoint, seamless. Well done.
Nancy Solomon: Thank you.
Bob: My issue is-- my question rather. I'm in Central Brooklyn as well and I used to see tons of fireflies when I was growing up here decades and decades ago. Now, I see almost none and it has been decades since I've seen hardly any fireflies. I'm wondering what happened? All right, there was an exchange. What I got for the fireflies I lost was tons of mosquitoes.
Nancy Solomon: [laughs] That's not a fair trade. Sarah, any idea? What's going on there?
Sarah Sloat: I think that's what scientists are trying to figure out. Again, climate change is making life very difficult for a lot of different types of animals, including insects, including fireflies. When there's drought or severe weather changes, that could really put a lot of pressure. Fireflies thrive in moist areas, that's why scientists say it could be helpful to have gardens with native plants because those help retain soil moisture in the ground for firefly larvae. They're actually larvae for about two years. They're only the glorious glowing bugs we see for about two weeks. But yes, I think that we're at the beginning of really identifying what's going on, but there's certainly signals that there is an issue.
Nancy Solomon: All right, let's go back to the phones. We have Claudia in Brooklyn on the line. Hi Claudia.
Claudia: Hi. Thanks for taking my call. You can get pretty spectacular firefly viewing over at Green-Wood Cemetery, outside the cemetery, but this year, it's been so minimal. It's almost hard to believe.
Nancy Solomon: That’s now two calls backing up the research, right?
Sarah Sloat: Yes.
Nancy Solomon: That's too bad.
Sarah Sloat: I would say these stories are important because, in a similar way, in the ‘90s and 2000s, people started to notice fewer and fewer bees. That was a signal to scientists to start digging into the problem. We're having a similar experience now with fireflies.
Nancy Solomon: We're going to go to Aaron in East Meadow, New York. Hi Aaron. You're on the line.
Aaron: Hi. How's it going?
Nancy Solomon: Good.
Aaron: I've got an angle from someone in the horticultural field. I'm a plant healthcare technician and part of my job involves spraying pesticides. We spray pesticides primarily for invasive insects like the spotted lantern fly and some of our customers, mostly our residential customers, spray for mosquito control. I suspect, and I don't have data to back this up, but I suspect that the use of pesticides and its growing popularity to control nuisance insects like mosquitoes could have broader implications for beneficial insects that keep our ecosystems healthy and for fireflies included.
Nancy Solomon: What do you think?
Sarah Sloat: That's definitely in line with the researchers have told me so far. All the experts I spoke with recommended cutting back pesticides in an effort to help fireflies along with tending to your garden maybe a little less often, less mowing, less leaf raking, because all of that leaf litter is where larvae like to sit and hang out so they could get big and strong.
Nancy Solomon: Well, now the reason why I have so many fireflies has been exposed. It's a lack of- -gardening and mowing. Let's go back to the phones. We have George in Wading River. That sounds like a nice place to be. George?
George: Oh, yes. Hi. Morning. Actually, yes, Wading River is a very nice place to be. My experience with fireflies is that I am inundated by them, absolutely inundated by them. On warm, humid evenings, they are attracted by my body heat. On occasion, I have to swat them away because there's just so many of them. Now, regarding lawn care, I really don't use too many pesticides or insecticides. I do mow it. I have a large lawn area. I mow it about once every two weeks. I have a lot of flowers also that attract pollinators, so I'm pretty sure that has a lot to do with it, but even on casual walks during the evening around the neighborhood, I see them everywhere. That's one for the fireflies, I guess.
Nancy Solomon: Thanks for your call, George. Any response there?
Sarah Sloat: I love it. I'm so jealous. I think that's something that the surveyors are trying to figure out is also what species are specifically threatened. There are about 30 in New York, there's five that seem particularly at risk. What you want in an environment is multiple different types of species. You want redundancy in your ecosystems. Here in New York City, what we're most likely to see is the big dipper firefly. They do those J-shape swooshes near the ground, but if you go outside of New York City, you're more likely to encounter multiple different types of species.
Nancy Solomon: Wow, I'm learning so much about fireflies. I just look at their twinkling and think they're so great looking, but now I'm going to have to go look for the dipper. 14% of the species that are going extinct, what effect will that have? That to me also says, “Oh, well, there are still a lot of fireflies left if it's only 14% of the species,” but what kind of impact could that have?
Sarah Sloat: Essentially, we need lots of different types of insects, lots of different types of insect species in order for food systems to work like they're supposed to in the wild. Overall, insects are-- some estimates say insects are declining at 2.5% each year in the environment and us in turn, we need insects. If one firefly species is cut out, we don't really know what the ripple effect is going to be but it's likely to be negative.
Nancy Solomon: Okay. Sarah, we're going to have to leave it there. Thanks for all the calls and thank you so much Sarah Sloat. Her piece in the Gothamist is titled Fireflies May Disappear So New York Scientists Are Trying to Count How Many Are Left. Thanks so much to all the producers on the show. I'm Nancy Solomon and this is The Brian Lehrer Show on WNYC.
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