IRA FLATOW: This is Science Friday. I’m Ira Flatow.

[JIM HENSON, “BEIN’ GREEN”] It’s not easy bein’ green.

IRA FLATOW: Frogs have been called the equivalent of the canary in the coal mine, sensitive indicators of the health of our environment. When frogs go silent, something is amiss. So we’re going to talk about why frogs are so important and how you can attract them, as you do birds, to your garden to make it a bit more easy being green.

Just what is the froggy equivalent of a bird feeder? Someone who knows is Dr. Itzue Caviedes-Solis. She’s assistant professor at Swarthmore College, in beautiful Swarthmore, Pennsylvania. Welcome to Science Friday.

ITZUE CAVIEDES-SOLIS: Thank you for having me.

IRA FLATOW: Nice to have you. You study frog conservation. Why do you care so much about frogs?

ITZUE CAVIEDES-SOLIS: That’s a great question. So I care about frogs because I love them. Because I think that every living organism deserves our respect and our care. But I think that they’re also really undervalued. They’re so amazing, and I just want everyone to know how cool they are.

IRA FLATOW: Do you have a cool favorite frog?

ITZUE CAVIEDES-SOLIS: I do. So the monkey wax frog lives in South America, and they produce their own sunscreen.

IRA FLATOW: No!

ITZUE CAVIEDES-SOLIS: Yeah. They’re so cool.

IRA FLATOW: Their own sunscreen?

ITZUE CAVIEDES-SOLIS: Yeah. We normally think of frogs, that they cannot be in the sun. But they have their own secretions and they can spread it all over their body. And they are just amazing.

IRA FLATOW: Wow. I talked about frogs being the canary. Are frogs having a tough time right now? How much have their numbers dropped?

ITZUE CAVIEDES-SOLIS: Yeah. So frogs are declining in number for different reasons. They’re one of the vertebrates that are the most threatened, according to the Red List in the IUCN. And they face a lot of challenges. They have habitat loss. They suffer from diseases– like a fungus that is affecting their health. So there’s different ways that we can help them overcome those challenges.

IRA FLATOW: Let’s talk about that. I want to make my backyard more frog friendly, so to speak. I want to make it a toad abode.

[LAUGHTER]

How can I attract frogs to my home?

ITZUE CAVIEDES-SOLIS: That’s awesome. So something we can do to attract frogs is make a pond. And these artificial ponds that we can have in our backyards help them because frogs reproduce in the water. So they have a place to lay their eggs and their tadpoles can grow. And if you make the pond a natural habitat that is suitable for other species like plants and insects, then the frogs will have a nice place to live and a lot of food that they can access.

IRA FLATOW: So I can build a simple one, then. Dig a hole, maybe put a liner into there for the water, and do what?

ITZUE CAVIEDES-SOLIS: Yeah. So something you need to consider for the liner is that it needs to be not plastic. Plastic get decomposed in small particles. And those particles can be eaten by the tadpoles. And that damages the tadpoles and decreases their health. So you can use something like a clay liner. And then you can put some rocks in the surroundings so the frogs can bask. Frogs are ectotherms, which means that they need external heat to do their activities.

Something else that can help them is using native plants. Because native plants don’t only help frogs, they help other insects in the ecosystem. And that will give shade to the pond and prevent overheating. Because when the water gets too warm, then the tadpoles will suffer.

IRA FLATOW: Right. Do I want to put a lily pad in there?

ITZUE CAVIEDES-SOLIS: I think you could. But I would prefer native species. If the lily pad is native where you live, I think you should go for it.

IRA FLATOW: Right. Do things like pesticides, fertilizers hurt them? Should I be careful of that?

ITZUE CAVIEDES-SOLIS: Yeah, for sure. So fertilizers have chemicals that also damage the tadpoles and the eggs and the adult frogs because they breathe through their skin. So it’s better to use organic fertilizers. And the pesticides, besides killing the insects, which are their food, then they also affect the growth of tadpoles.

IRA FLATOW: Interesting. I’m glad you mentioned that. I mean, if I build a frog habitat like that, what are the odds that a frog is really going to show up?

ITZUE CAVIEDES-SOLIS: That’s a great question. After you put all that effort, are they going to show up to the party?

IRA FLATOW: Exactly.

ITZUE CAVIEDES-SOLIS: So I think that it depends on where you live. Something you can do is use iNaturalist, which is this app that helps you find the nature around you. So you can look if there are frogs close by in your neighborhood or your workplace or wherever you build the pond. And then, if they’re close by, they’re more likely to appear in your backyard.

IRA FLATOW: So they will find it. If you build it, they will come.

ITZUE CAVIEDES-SOLIS: They will if they’re around.

IRA FLATOW: Yeah. How do they find it? Is it smell? Do they have special sensors that know where the water is?

ITZUE CAVIEDES-SOLIS: Yeah. So that’s a really good question. So frogs can absorb water through their skin. So they’re really sensitive. So they can sense, for example, if it rains or if there’s water close by because they need to regulate the humidity in their bodies. So it’s not super clear how they do that. There is still research going on to figure that one out.

IRA FLATOW: That’s cool. What do you wish that people knew about frogs?

ITZUE CAVIEDES-SOLIS: Well, I just want them to know how cool they are. I think that frogs have been around with us for so many years– like millions of years– and they’re still here and they’re so resilient. So I want them to know that they have all these amazing superpowers to do so. They can overcome disease and disturbance. And they do that with a permeable skin. If I was a frog and I jumped in a pond, I would probably die. Because humans are not that resilient.

And then they also are nocturnal. So I want them to know that, even though we don’t see them, they are there doing amazing things. This one that I like has their own sunscreen, but there are others that have different adaptations. Some frogs turn blue. Some frogs have claws that are retractable like a wolverine.

IRA FLATOW: Whoa.

ITZUE CAVIEDES-SOLIS: So there’s so many species. So they’re like the superheroes of the night.

IRA FLATOW: Wow. And one of the superpowers they have is metamorphosis. That is incredible, going from a tadpole to a frog.

ITZUE CAVIEDES-SOLIS: Yeah, that’s one of my favorite things, too. So their lifecycle starts as an egg. And then the tadpole is aquatic. And then the adult can go to land. Some of them can even climb trees and glide from the trees.

So when you look at that lifecycle, you can imagine how life evolved on Earth. Like life started in water. And then we crawled out of water and now we have all this amazing diversity on Earth. And you can see that happening in slow motion with a frog just by looking at their development.

IRA FLATOW: I think it really kindled– certainly in me– rekindled interest in me and in our listeners I hope.

ITZUE CAVIEDES-SOLIS: Yeah, I hope so, too. And I think that what we need is more advocates for frogs. I feel like we have a lot of advocates for pandas and elephants. But I think we need a stronger crowd to help the frogs.

IRA FLATOW: There you have it. Thank you for taking time to be with us today.

ITZUE CAVIEDES-SOLIS: Of course. Thanks for having me.

IRA FLATOW: Dr. Itzue Caviedes-Solis, assistant professor at Swarthmore College, in Swarthmore, Pennsylvania.

[FROGS, TOADS, AND INSECTS VOCALIZING]

I’ve got to build a toad abode in my backyard. But you know what? There’s another way to help frogs and toads. And that’s by lending your eyes and your ears to the scientists who study them. Yep, it’s time to reactivate your Citizen Scientist genes, as you have done in the past. And that’s because April is Citizen Science Month. So we’re kicking things off with a totally cool project, called FrogWatch.

Here with the “ribbiting” information on how you can participate in FrogWatch is Carrie Bassett, National FrogWatch USA coordinator and education mission manager for the Akron Zoo, in Akron, Ohio. Welcome to Science Friday.

CARRIE BASSETT: Hi, Ira. I’m happy to be here.

IRA FLATOW: Nice to have you. Let’s get right into this. What is FrogWatch all about?

CARRIE BASSETT: So FrogWatch USA is a national Citizen Science project that we actually go out and we study and listen to frogs and toads and their calls. So we encourage regular everyday people to learn how to identify frogs and toads by their calls alone. And then we go out and monitor and see what frogs and toads are living where and what kind of wetlands they’re in and what kind of weather they’re calling in.

And then we enter all of that information into a national database that’s open source for anybody in the world to access, so that scientists can use that data to track where exactly and when exactly the frogs and toads are calling. So it’s a really exciting program that we can use to track the different demographics and habitats that the frogs are currently calling in. And we appreciate the everyday people that join us in this journey.

IRA FLATOW: We’re talking about toads are OK here, too, right?

CARRIE BASSETT: Yes. Yep, frogs and toads.

IRA FLATOW: Give me an idea of what a typical frog watching event looks like.

CARRIE BASSETT: So we do trainings where we have people come out, and we teach them everything they need to know in order to be a citizen scientist with FrogWatch USA. But then, once they’re trained, the typical event is that we go out and do observations. And we do our observations in the evening. So at least a half an hour after sunset. So you have to be ready and willing to go outside a little bit after dark. And then we go to various wetlands all across the country and we listen to the frogs and toads that are calling.

And it’s about a five-minute total commitment that you have to do in order to do those observations. We do two minutes of just being quiet and letting the frogs get acclimated to our presence in the wetlands. And then the observation itself actually lasts three minutes. And we record the calls of the frogs and toads that we hear, along with weather data and location data to go along with it.

IRA FLATOW: Can we do a little bit of training here right now? Can we practice a little bit and play some frog sounds?

CARRIE BASSETT: Yeah, I think that sounds exciting.

[FROGS, TOADS, AND INSECTS VOCALIZING]

IRA FLATOW: Wow.

CARRIE BASSETT: Yes, this would be a typical, probably spring– late spring, early summer– evening if you’re out at various observation sites. So when I listen to that, I can actually hear three different frogs and toads calling to us. When you listen, there is kind of a really short trill that’s going on in the foreground. And that would actually be a great tree frog. And then there’s a longer trill sound going on in the background. That’s an American toad.

And then kind of a little bit further in the background, constantly playing over the top of all of the other frogs, you do hear some spring peepers, which are one of my favorites.

IRA FLATOW: Speaking of which, do you have a favorite frog?

CARRIE BASSETT: So that’s a hard question. I do have to admit that spring peepers are probably my favorite frog. They are a little, small tree frog that is probably one of the loudest frogs that we have here in Ohio. And with their little tiny size and how loud they call, it’s pretty exciting. They’re also one of the first harbingers that tell us that spring is here.

So I know when I go outside and hear the spring peepers, it tells me that good weather is coming around the bend, and hopefully we’ll be able to celebrate a nice warm spring. So they’re one of my favorites.

IRA FLATOW: I think there are tree frogs that freeze. Is that correct?

CARRIE BASSETT: Yes. They’re probably my second favorite frog. So those are wood frogs. And they’re these adorable little frogs, also very small. And they look like they have a little bandit mask on their face. So they have a little black mask that goes across their eyes. But they are the only frog in North America that lives above the Arctic Circle.

That means that these guys, when it gets cold, they actually have very special sugars in their blood that allow them to freeze solid. So they turn into little like frog-sicles.

IRA FLATOW: No!

CARRIE BASSETT: Yeah. Crazy. They turn it a little frog-sicles. And they’re able to survive the winter and then thaw out in the spring because of the natural sugary antifreeze they have in their blood. And they’re actually being studied, with the hopes that maybe they can help humans someday when it comes to things like organ transplant. Like being able to maybe freeze organs and to move them across the country for transplants possibility. So it’s really, really cool.

IRA FLATOW: Well, if that doesn’t get you interested in frogs, nothing–

CARRIE BASSETT: Right.

IRA FLATOW: Nothing will. OK. So let’s talk about FrogWatch. So you collect this huge database, right?

CARRIE BASSETT: Yep.

IRA FLATOW: What can it tell us about frogs?

CARRIE BASSETT: So the big FrogWatch database, because of the different information we collect whenever our citizen scientists go out and do an observation, we collect information about the weather over the last couple of days. We collect information about the weather that is happening during the observation. We collect information about the location of where the frogs are calling, what kind of wetland they’re in, where the water comes from, all kinds of fun information like that, as well as what kinds of frogs are calling and how intensely they’re calling.

Because it’s very hard to go out, as you might imagine, and count frogs individually in a wetland. So we actually do a measurement for the intensity of how many are calling. And then all of that is tracked also with the date and time of the observation. So we have a lot of information that you can manipulate and go to our data collection platform, which is called Field Scope. And you can manipulate all that data to find all kinds of crazy things.

IRA FLATOW: This is Science Friday, from WNYC Studios.

One of the things I’d be searching for is if there’s some abnormality in the frog calling in a certain place. I mean, are frogs missing, which, as I said before, is usually one of the signs that something is going on in nature?

CARRIE BASSETT: Right, exactly. Yeah, frogs are a really good– as you mentioned earlier, they’re a canary in the coal mine. They’re an indicator species for wetland health. So by being able to track where the frogs and toads are calling, we can actually go back and look and evaluate what the health of that wetland may be doing. Because frogs and toads are amphibians, which means double life. That’s what it literally translates to. Meaning that they are found part of the time of their life in the water and part of their time on the land.

So if anything weird is going on in an environment, they pick up both of that. And also, because they have permeable skin– meaning they absorb everything through their skin– they can pick up anything that’s going on in a wetland. So if something bad is happening, it shows up in the frogs and toads first.

So by being able to track them, it gives us an early indicator that something might be going on in a wetland.

IRA FLATOW: Carrie, this sounds like a really cool Citizen Science project. How can people get involved in this?

CARRIE BASSETT: Yeah, it is an awesome project. To get involved you just need to either reach out to your local FrogWatch chapter. And you can come to the Akron Zoo website, type in Akron Zoo FrogWatch, and you can come to our website.

IRA FLATOW: This could be like a life changing experience for people who never thought that they would enjoy or appreciate frogs.

CARRIE BASSETT: Right. Yeah, I do get some people who are like, oh, my gosh, they’re just frogs. Like, who cares? Which I think is sad. Because frogs are just awesome, in general. But then they’ll go through trainings and stuff, and they’re so interested in all of the different things. Like, the idea that the wood frog that freezes solid or the great tree frogs that actually change color a little bit.

But I noticed the biggest change is people that become our volunteers love to also educate other people. I had a volunteer in my own chapter a couple of years ago that said she was out on the trail and these people were stopped, and they were like, what’s that sound? And it was during the day. She wasn’t doing an observation. But she was so excited to stop and identify the frog and tell them about the frog.

And the people got really, really excited. I think the educational piece is definitely a life-changing piece for most people.

IRA FLATOW: This sounds so exciting. Carrie, I want I want to thank you for taking time to be with us today and making us more excited about frogs.

CARRIE BASSETT: Thank you. It’s been a great time.

IRA FLATOW: Carrie Bassett, national FrogWatch USA coordinator and education mission manager at the Akron Zoo, in Ohio.

By the way, if you’re looking for more opportunities to explore nature with the kids in your life, we have just the thing. As I said before, April is Citizen Science Month. And we’ve got lots of fun projects and resources to help you get involved. Check out sciencefriday.com/citizenscience for information. Let me say that again, sciencefriday.com/citizenscience.

Copyright © 2023 Science Friday Initiative. All rights reserved. Science Friday transcripts are produced on a tight deadline by 3Play Media. Fidelity to the original aired/published audio or video file might vary, and text might be updated or amended in the future. For the authoritative record of Science Friday’s programming, please visit the original aired/published recording. For terms of use and more information, visit our policies pages at http://www.sciencefriday.com/about/policies/.