Science Friday - Science From Iowa’s Prairies | Planning To Go See Cicadas? Here’s What To Know

Episode Date: May 3, 2024

Science Friday is in Ames, Iowa, home to prairies, greater prairie chickens, and an array of wildlife. Also, the co-emergence of two periodical cicada broods is underway. Scientists have tips for how to experience the event.Science From Iowa’s PrairiesThis week, SciFri is coming to you from Ames, Iowa. We’re kicking off the sciencey Iowa celebrations by spotlighting some of the plants, animals and unique ecosystems of the Hawkeye state. Ira talks with Charity Nebbe, host of the “Talk of Iowa” at Iowa Public Radio, about the state’s largest prairie restoration project, the conservation of prairie chickens, and its rebounding wildlife.Planning To Go See Cicadas? Here’s What To KnowIn parts of the American South and Midwest, two broods of cicadas are emerging: Brood XIX, known as the Great Southern Brood, and Brood XIII, called the Northern Illinois Brood.The dual emergence of these two particular broods is a rare event, since the Great Southern Brood emerges on a 13-year cycle and the Northern Illinois Brood emerges on a 17-year cycle. The last time they were seen together was in 1803. The two could overlap this spring in parts of Illinois and Iowa, where cicada enthusiasts will gather in parks to observe the emergence.“Plan to spend an afternoon or two,” recommends entomologist Dr. Laura Iles from Iowa State University. “Here in Iowa it tends to be pretty patchy even within a park, so talk to someone, a ranger, about what path to hike on and the best places to go see them.”Ira Flatow speaks with Dr. Iles about the fascinating life cycle of cicadas, how best to approach cicada tourism, and why gardeners should hold off on planting new trees this year.Transcripts for each segment will be available the week after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Are you planning some cicada tourism for the spring's special emergence? Talk to someone, you know, a ranger or somebody about, you know, what path to hike on and the best places to go see them. It's Friday, May 3rd, and you guessed it. Today is Science Friday. I'm SciFRI producer Kathleen Davis. We all know the telltale signs of cicadas. They're distinctive sounds, the exoskeletons that they leave behind. In parts of Illinois and Iowa, not just one.

but two cicada broods are expected to emerge at the same time this spring. Because these two broods have different life cycles, they haven't been seen together since Thomas Jefferson was president. We'll talk about that story a little later, but first, here's Ira Flato with the biggest science stories of the week. This is Science Friday. I'm Ira Flato. Coming to you today from Iowa Public Radio in Ames, Iowa. Iowa is a state that to many folks is synonymous with cool.

Corn, right? You think of Iowa, you picture cornfields. So I wanted to start the show by highlighting some of the other plants, animals, unique ecosystems of the Hawkeye State that we non-Iowanes don't know much about. And who to better act as our tour guide to some of Iowa's natural treasures than one of Iowa Public Radio's own treasures, Charity Nebby, the host of the talk show, Talk of Iowa, heard on Iowa Public Radio in Iowa City. Charity, welcome to Science Friday. Well, thank you so much, Ira. It's a delight to be here. You're welcome. I want to start off by talking about how Iowa's ecosystem has changed. I mean, the landscape used to be dominated by tall prairie grass or wetlands. What happened? Well, European settlement is what happened. And when

you say, you know, you think of corn, when you think of Iowa, you're not wrong. We have corn and soybeans covering acres and acres and acres of land in Iowa. A lot of our landscape is covered by this monoculture now. But before European settlement, Tallgrass Prairie was the most common ecosystem in the state. And it covered 85% of Iowa's land. Wow. And Iowa is actually has the unique status of being the most biologically altered state in the entire nation. Tallgrass Prairie went from covering 85% of Iowa's land.

Today it covers less than 0.1% of land in the state. So European settlement, obviously, it changed everything in this country, but it really dramatically reshaped the landscape in Iowa. But there have been some efforts, right, to recreate some of that lost prairie. And I'm thinking of the Neil Smith National Wildlife Refuge. Tell me a bit about how that came to be. Well, the Neil Smith National Wildlife Refuge in, it's very near Des Moines. It's the nearest town is Prairie City, aptly named.

And that came about. Neil Smith was a congressman who was influential in creating it. But that was farmland that was entirely reconstructed into this native ecosystem. And so now when you visit the Neil Smith National Wildlife Refuge, you can really experience what it's like to be in the middle of a tall grass prairie with over 5,000 acres of reconstructed tall grass prairie. They also have a herd of bison on the land. Yeah. And it's an opportunity to really feel, you know, what it was like. I don't think you can ever fully really understand what it was like to stand in this just ocean of grasses that went on and on and on because it's pretty easy. to see far in Iowa. So you can always see power lines. You can always see roads, that kind of thing. But still, it's pretty special. And there are other really wonderful prairie refuges around the state. There are a few tracks of Virgin Prairie that you can visit around

the state as well. And, you know, it's, it's really, really wonderful to see a lot of landowners in Iowa have reconstructed prairie on their own land. And now we're seeing people do it in their front. You know, yards too, which is really cool. That is cool. Let's talk about some of the birds, some of the interesting birds in Iowa. I know you have a funny story about trumpeter swans who were brought to the Iowa State campus. I'd love you to tell us about it. Yeah, well, I'll start at the beginning, which is, so in Iowa, when you talk about most native species, again, the land was transformed, but so were the wild animals. So almost every species in the state has kind of the same. story where they were hunted to the point of extirpation after European settlement. And then there

have been some incredible comeback stories. And the trumpeter swans are one of those just incredible stories. The last nesting pair was spotted in Iowa in 1883 until the Iowa Department of Natural Resources decided to try to reintroduce mating pairs of trumpeter swans. That started in 19. 1993, and so they would put these pairs, you know, landowners would volunteer to host a pair of mated swans on their land. And Iowa State University was also involved, very heavily involved in this project. And there's a pond on campus. I guess it's Lake Laverne is the name of it. But a pond is a really better description. It's not that big. And it always had mute swans and still does have mute swans.

Lake Laverne, but they decided to put a pair of trumpeter swans on campus. And that was when I was a student. And so this mated pair of trumpeter swans was there. And they are giant birds, Ira. They're so big. Their wingspan is well over six feet. And they can also be a little territorial and aggressive. And swans will be. I know all about swans. Yes. So the male trumpeter swans started really protecting their territory. He attacked cars on the road and ripped windshield wipers off and no one got hurt and they decided they also did not successfully raise signets on Lake Laverne. So they relocated that pair and brought mute swans back. But the trumpeter swans, as of 1993, there were over a hundred pairs of trumpeter swans nesting in the state. And huge flocks passed through each fall and spring. You can go to

Ada Hayden, they're in Ames, a small park and just see hundreds of trumpeter swans every fall. It's really extraordinary. And really, it's also a testament to the power of individuals to really make a difference. And, you know, the birds are not without their challenges. Lead poisoning is a common challenge to trumpeter swans today because of legacy lead that's still in the waters of Iowa. But It really is an incredible comeback story. Well, let's talk about another iconic bird native to Iowa. And I'm thinking of the Greater Prairie Chicken. So for our listeners who don't live in your neighborhood are not familiar with them,

give us a short Prairie Chicken 101 because they are fascinating too, aren't they? They are. And even a lot of Iowans have never heard of the Greater Prairie Chicken. The story of the Greater Prairie Chicken is kind of similar to the story of the passenger pigeon. They were incredibly populous before European settlement, and they were one of those rare species that actually thrived on European settlement. The kind of mix of farmland and grassland was perfect for them. So they were everywhere, and then they were hunted and hunted and hunted to the point where they very nearly disappeared and did disappear from Iowa. But there's a very small flock in southern Iowa that has been reintroduced.

It's in the Kellerton Grassland area. It's managed by the Iowa Department of Natural Resources, and there are fewer than 100 birds down there. Wow. Yeah. But you can go and you can see these birds. Every spring they put on this incredible mating display, as male birds often do.

But the greater prairie chicken, they look like kind of like a pheasant, a smaller grouse or something like that. But they puff up their necks and they have these orange air sacks that inflate. And so they have this just brilliant orange color. And then they strut around a leck, an open grassland area. And they sometimes fight with each other to show off how powerful they are for the ladies who are gathered around the edges of the leck. And they make this call. It's called booming, which I feel like is kind of a.

a misnomer because it's not all that loud, but it's more like of a woo-woo-woo noise. And they put on this show for hours. And you went to see this, right? I did. I did. And it's extraordinary to see. It's also extraordinary to think about how common they were, how they lived among us. And of course, you know, humans are really bad at understanding their impact on the land and on species. I'm sure that the settlers thought that they could never kill so many that they would disappear, and yet they did. Is there any way to save them? You know, this small flock is doing

okay, but because of the way that our land is broken up now by roads and, you know, farmland and cities, et cetera, there really aren't very many places that they have enough contiguous habitat that they can live. You can go see them in Nebraska, for example, they have. They have more of them than we do in South Dakota. But yeah, they, they just, there aren't many places in Iowa where they can successfully exist. There's another, there's another species that's made to come back in the state. And I'm talking about the bald eagle. And is it true that you saw a tree full of bald eagles? That's hard to imagine. Every winter I see trees full. They're almost as common as pigeons sometime along the, the Iowa River. I'm in,

Iowa City. That's where I'm based. And, you know, of course, Ira, you know the story about bald eagles, which of course is that they almost disappeared because of DDT, which, you know, was everywhere in our environment and made their eggs very thin so they couldn't successfully breed. But I grew up in Iowa and I never saw a bald eagle until I was 12 years old. And now a day doesn't go by when I don't see a bald eagle. They're so common in Iowa again. And so. incredibly beautiful. There are so many nesting pairs. And one of the coolest things you can do is check out the Raptor Resource Project in Decora, Iowa, because they run a bald eagle cam. And if you just search Bald Eagle cam, you know, you can throw Decora in there too. You get to

watch a mated pair of bald eagles rear their young up close and personal. There are many nesting pairs around Iowa. But right now there's one nesting pair in Iowa that you can watch up close and personal. And, oh, it's incredible. And I'll tell you, when my kids were little and I got so excited every time I saw a bald eagle, finally they were like, Mom, we see them every day. Why do you get so excited? And I said, because when I was growing up, I never thought my kids would see a bald eagle. And here they are. Well, thank you, Charity, for being up close and personal with us today. Absolutely. Thank you, Ira. Charity Nevy, the host of Talk of Iowa at Iowa Public Radio, based in Iowa City. This spring, you may hear a familiar sound. Cicadas, yes, they can be pretty loud. And in fact,

in parts of the Midwest and the American South, two broods of cicadas are emerging. brood 19, the Great Southern Brood, and Brood 13, the Northern Illinois brood. The dual emergence of these two particular broods is a rare event. The last time they appeared together was in 1803. Both brews can be seen in Illinois and Eastern Iowa. And joining me now to talk about these broods is Dr. Laura Isles and tomologist at Iowa State University in Ames, Iowa. Welcome to Science Friday. Thank you so much. It's a pleasure to be here. It's nice to have you.

Oh, Mike, this double brood emergence sounds pretty exciting. Are you excited by it? As an entomologist, I am definitely excited. I'm excited to have any brood. You know, living in one place, they don't happen all that often. And so I was lucky in 2014 when we had a brood right here in Central Iowa. But I'm definitely going to travel to eastern Iowa and see at least the brood 13 emerging there. So I'm very excited about it.

Well, tell me why you would travel to see the brood. What is so special about what's going on? Well, so these are the periodical cicadas. And so we've got the 13-year or 17-year broods. And so there's just thousands of them upon thousands at the same time and in the same location. Well, what do you see? Are they flying? What are they doing that?

It's so amazing. Yeah, so they're kind of doing a lot of things. So, you know, the singing is what always, you know, catches people. So the males will gather together in a chorus and they'll sing together and the sound is kind of deafening. But, I mean, to me, it's kind of beautiful. Maybe because I get to travel and go see it, don't have to put up with it all day long. But, yeah, cicadas, there's a term the cicada specialist user. They say they're predator foolhardy, which essentially means they really don't even try to run away.

So you can really look at them and you'll be able to see females laying eggs. you'd be able to see them just sitting on the undergrowth, hear them singing in the trees. So you really can go and just kind of immerse yourself in cicadas, if that's something you would enjoy. Well, speaking of enjoying it, then let me ask you about the singing. I never heard it described as singing, but it is, right? I mean, are they singing to communicate with each other, or are they singing to keep predators away? Because they're pretty loud, right? Right, they're very loud.

And they're singing to communicate. So it's just the males that can sing and they're communicating with the females come here. They have a pretty short, you know, lifespan, a few weeks as adults. And really their job is to mate and lay eggs. And so the males gather together so they can be even louder and attract females to the area for those mating opportunities. I know we're not supposed to kind of anthropomorphize with insects, but I think about them kind of underground for 13 or 17 years. I don't know. I kind of think, well, it's kind of cold. I don't know if they even, like, see each other under there or come across other cicadas.

So they're probably kind of alone. And then this is their chance to emerge and be in the sunlight and fly and, you know, meet other cicadas. Yeah. Wow. And can you tell different broods apart by the songs they sing? I mean, could you hear one and say, oh, it's that one? It's where they are. And, oh, look, there's another one. Yeah, so you can tell the different species of cicadas apart, and a brood is just kind of a term for the cicadas that will emerge in a certain, like, geographical area in a certain year, and each brood will have several species in it. Yeah, so there is some evolutionary advantage then of this lifecycle style. Yeah, so this very long life cycle style, the belief in probably likelihood is that it keeps, any predators from, you know, getting that same life cycle. So it's not unusual to have like plants to like only produce seeds every few years or in this, you know, so it's like they, they just escape from predators that way because there's really no predator that could go

without, you know, feeding for 13 or 17 years. And then they just come out in such huge numbers that no predators could eat all of them. So they're very vulnerable to birds and snakes and lots of other things, but there's just so many of them that they can't possibly eat all of them. Well, you kind of answered the question. If I was a predator and I saw a gazillion of these cicadas coming out, I'd say it's party time, right? I mean, what feeds on them? Yeah, so many species of birds do, you know, certainly raccoons. Basically anything will eat them.

They're not like wasps. They can't sting. They don't contain any chemicals. I mean, they are really just, like they say, predator fool party. They don't even, you know, fly away, really. So they just don't have a big strong response when something's coming to eat them. Because, again, they're just, like, it's such huge numbers. That's how they've evolved to do it is just to be present in such huge numbers.

Yeah. So where do they lay their eggs? I mean, can you see them actually doing it? Yeah, definitely. So it's the female, and she has a structure called an ovipause. Ova is just, you know, named for eggs. So she has this structure that she can kind of cut into the tree branch. So she'll be on the underside of a twig, usually, and she'll just be poking this ovipositor into it.

So she'll make a little slice in the twig, lay about 20 eggs in there. And then she'll just move a little bit further down the twig, make another slice, lay some eggs in it. And so you'll see just like a little series of almost V-shaped slices in a twig where the FIVA has laid eggs. So you can definitely watch this happening. If you go into an area after cicadas have been there, you can see it. Sometimes you'll get some twig dieback from the damage called flagging. So it's definitely something pretty noticeable in areas where there's been a brood emerge. So where do they get to the ground stage of this?

So the eggs will be in that twig about six to ten weeks. And then they hatch and then this tiny little nymph, just almost clear, white, whitish-colored tiny nymph hatches out of it and falls to the ground and then burrows under the ground and seeks out a root to start feeding and they're not terribly picky at first. They'll feed on pretty much any plant root that they run across. And then as they get, you know, larger,

they seek out tree roots and set up feeding sites and feed on those. Wow. You know, maybe it's because the eclipse was so recent. But this special cicada event makes me think we might see some cicada tourism in Illinois and possibly eastern Iowa. Is that a real thing? Oh, for sure. I've definitely been on lots of message boards where people are talking about planning trips. I know a lot of us here in central Iowa, since we won't have any, we'll drive out to eastern Iowa. I think this will, I mean, I was one who traveled eight hours for the eclipse and it took, you know, what, like 12 hours to get home with all the traffic. I know. I've been there. Yep. Yep. Yep. I mean,

And the eclipse is like a really kind of intense moment, you know, two to four minutes and then everyone hits the road at the same time. Like the nice thing about touristing for cicadas is you can go there all day. You can go there for a few hours. Like there isn't quite that like, you know, once you find a nice area, you're not worried about cloud cover and all the other things that went into eclipse chasing. Yeah. This is low stress. Good point. Now it is spring and people are attending their gardens.

Should local gardeners adjust? their plans while these cicadas are doing their thing. Yeah. So, and again, they tend to be patchy where they're emerging. So, you know, if your neighborhood is a place where you've known in the past, you know, that, you know, 13 years ago or 17 years ago, they emerged here, then you very likely they're going to emerge again this year. And our recommendation is this might not be the best spring to plant a new tree because a little bit of that twig damage can be harder on new trees, you know, maybe fall planting is just as good for trees. And if you have, you know, I spend my money in my landscape. So I have some Japanese maple looking trees that, you know,

I spent, you know, $250 for and I love them and prune them delicately each spring. So that would be the sort of tree that you'd, you know, just go online by like tool fabric, garden netting, row covers, you know, purchase some of that and cover them up for the few weeks to prevent that egg But again, it would have to be something like pretty high value and small. A large tree. Well, first of all, you couldn't cover it very well. And, you know, second of all, the tree is just fine. A little bit of just minor damage.

Okay, that's good advice. Okay, now since you've whetted everybody's appetite for going out to see the cicadas, I'm really, I'm excited. For people who want to see them, maybe do some cicada tourism, how can they best go about this without hurting the cicadas? So the key is to kind of finding a place to go. And I've got an app called Cicada Safari right now. There's, you know, website Cicatamania is great. Like find out like kind of what parks in your area, you know, state parks, city parks have had cicadas in the past. Many of them are kind of advertising it.

And I know in Illinois where those two broods are really overlap, there's, you know, some county parks and things planning kind of festivals and fun activities for kids around it. So, Just kind of pick your location. Here in Iowa, it's really along, you know, river areas between Iowa City, Cedar Rapids is a very likely place. That's probably where I'm going to head. So you pick your location, you know, they're already emerging in the south. We expect them kind of late May. Well, I was going to ask, is there an ideal time?

Is there a peak date? Unfortunately, it's the soil temperature being about 64 and 8 inches. But that's hard information to get for your area. Yeah, the southern U.S. are just starting to emerge in the Missouri, southern, probably early May, and we won't be here up in the Upper Midwest until, you know, May or June. But, yeah, set those dates and then, you know, just be kind of prepared to travel and plan to spend, you know, an afternoon or two. Here in Iowa, and I know this isn't like everywhere, here in Iowa, it tends to be pretty patchy even within a park. So, you know, talk to someone, you know, a ranger or somebody.

about, you know, what path to hike on and the best places to go see them. You know, I was going to ask you how you convince people that these are worth going to see, but I just have to listen to your enthusiasm. And I think you've convinced a lot of people, not to be afraid of them, go out and go see some cicadas. I hope so. It's the sound, and you can hear it from a distance. And as you just hear that sound and then walk into an area where the males are chorusing, it's pretty cool. I encourage it.

I've never heard the word chorusing apply to a, Cicada before. So thank you very much for that, Dr. Iles. Dr. Laura Isles and tomologist at Iowa State University in Ames. Thank you for joining us. Thank you so much. And we have a story on our website all about this special double-brewd emergence. Go to sciencefriiday.com slash cicadas. Notice I put the S on that. ScienceFriday.com slash cicadas with an S. And that's all the time that we have for now. A lot of folks help make the show happen this week, including Beth Ramey, Santiago Flores, Diana Plasker, John Dancosky, Robin Casmer, and many more. On Monday, we'll talk about why it's so important to preserve plant specimens.

But for now, I'm SciFri producer Kathleen Davis. Have a great weekend.