Marcos Trinidad 0:00

[sound of a large fountain] I'm laying on the ground, and I'm sneaking up behind this frog. It's in between a couple of watery lilies, and I'm channeling all the Kung Fu training that I've had, so I can be quick and direct with with grabbing this frog. [theme music] [splashing sound] And I missed. [laughs]

Marcos Trinidad 0:33

Hey, this is Marcos Trinidad and you're listening to Human/Nature. Every week, we'll get out into the nature of your neighborhood with the help of people who see the world a little differently. This week, we're out in Playa Vista on the west side of LA. We're close enough to the ocean, you can smell it. But that's not why we're here. Right now, we're visiting a manmade concrete park pond. It's just outside a bunch of tech offices like Google and Yahoo.

Dr. Greg Pauly 1:00

[ambient outdoor sounds] I've actually never checked out these little ponds. I mean, they're just they're fountain ponds. They're only a handful of years old.

Marcos Trinidad 1:07

[fountain in background] We're out here with Dr. Greg Pauly. He's the curator of herpetology at the Natural History Museum of LA. That means he studies reptiles and amphibians.

Dr. Greg Pauly 1:17

[fountain amplified] Oh, yep! That's a bullfrog. You guys see that looking right back at us?

Marcos Trinidad 1:22

And if we can, we want to catch one of these resident bullfrogs. [fountain] [bullfrog calls] We're tracking it by the sound of its call. It is this very [laughs] like baritone deep bass call. And it it will call out you know, two or three times, uh and then it will go silent. And we've heard it a couple of times already. [fountain and bullfrog calls]

Dr. Greg Pauly 1:51

Look at that honker over there. [bullfrog call] Look at that thing. It's huge! [Marcos in background: Wow!] That's a good sized bullfrog.

Marcos Trinidad 1:57

Greg, a master frog snatcher, manages to grab one straight from the water. [sounds of someone stepping into the water] [in background, two people say: Whoa!] It's about 10 inches long, stretched out from its nose to its feet.

Dr. Greg Pauly 2:12

And he's got these sort of big Popeye arms. That's because he's a male, and he's going to be holding tight and hopefully holding on to a female, if he manages to attract one. Um, he's got these pretty decent sized legs, probably about the size of frog legs you might have seen [Marcos: Mmm hmm.] cooked up in a fryer somewhere.

Marcos Trinidad 2:20

[fountain in background] And actually, bullfrogs were introduced to the region because people wanted to eat 'em. But now, they're not as popular. And that's allowed bullfrogs to take over, in LA and across the country. They're in park ponds like this one, but also in our natural creeks and streams. And maybe you've guessed it by now: these frogs are invasive. They're big, for starters.

Dr. Greg Pauly 2:52

The largest American bullfrog I've ever seen in my life, weighed 2.2 pounds.

Marcos Trinidad 2:58

It's like a small Jabba the Hutt. [laughing]

Dr. Greg Pauly 3:00

Yeah, I mean it's, it was a huge, huge, huge, huge frog.

Marcos Trinidad 3:04

And they eat anything. Ducklings, baby turtles...

Dr. Greg Pauly 3:08

There's actually one record of a bullfrog [sounds of footsteps] eating a baby skunk.

Marcos Trinidad 3:12

They even eat other bullfrogs, and they don't make exceptions for family. They're bullies. And because they're literally eating other frogs, our native populations are declining. Honestly, with habitat shrinking, the frog situation in the region today is kind of sad. We don't have a lot of the species we used to. After we went looking for frogs, I sat down with Greg to talk about nature in LA, historically speaking. But Greg says, a couple 100 years ago? LA was kind of a frog paradise.

Dr. Greg Pauly 3:45

Miles. You know, acres and acres and acres of swampy habitat.

Marcos Trinidad 3:50

Back then, things looked different. So I'm sorry to bust that whole LA is a desert myth, but over 100 years ago, the LA basin was basically a big marsh. [original music] Today on the show, we're talking all about that historic wild LA, and what we can do to recapture some of that marshiness. All that after the break. [music out] [break]

Marcos Trinidad 4:24

If you want to understand what the landscape looked like, Greg says to imagine a storm. In the winter or spring, water would fall in the mountains and then run down into the San Gabriel and LA rivers.

Dr. Greg Pauly 4:37

But the crazy thing about those rivers is like the fresh water in those rivers struggled to actually get to the ocean. When it got down into the flat, you know, got down into the San Fernando Valley, it spread out, so you'd have a big storm and the LA River would just quickly overflow its banks. And by the time that the storm waters receded, you know, the w-, its, the channel would have shifted some. So you just had huge amounts of water coming down. So it was a great time to be a frog. Um, but pay attention to all of the watery place names around LA that people never even think of. Like a really obvious one that like most people will be familiar with, but probably haven't thought about is like La Cienega Boulevard. [Marcos: Mmm.] It's like, okay, if you know a little bit of Spanish, you realize that [Marcos laughs] that basically, that's like the swamp. And you're like, Well, why? What's that about? Well, that's because there used to be a giant swamp. On the north side of the Baldwin Hills, like there was a swamp that was probably something like 10 miles long and up to three miles wide. [Marcos: Wow. Yeah.] Like on, on the north side of the Baldwin Hills, like, that's just crazy to think about that there was like a huge swamp there not that long ago. There's this absolutely wonderful early description where someone's talking about the challenges of crossing the LA basin. And they say, you know, the the biggest challenges getting through this region, are trying to keep your wagon wheels from getting stuck in the mud. And there's a grizzly bear around every corner.

Marcos Trinidad 6:02

[laughing] Which, what I wouldn't give to to experience those those challenges. Now, when we look at Polliwog Park or Frogtown, were there specific kind of frogs there or specific species that existed in these areas? And how did those those names get assigned?

Dr. Greg Pauly 6:24

The name Frogtown is, is a really appropriate name for that particular region. This is right around the Glendale Narrows, and so what happens there is that the bedrock is very close to the surface. And so what was happening there is that there were large numbers of um frogs breeding and multiple species, certainly our Baja California tree frog. But the main species that was in that region was the Western toad. And, you know, around the same time and kind of mid-summer, all of a sudden, 1000s upon 1000s, of little tiny toadlets, about the size of your pinky fingernail, actually a little smaller than your pinky fingernail, would then be hopping across the landscape. And so if you want to be more sort of technically correct, it should actually be called Toad Town because [Marcos laughs] it was predominantly Western toads. People describe it as, like being unable to walk without accidentally stepping on one, because there were just so many so many little tiny toadlets hopping around. It's still around in tiny numbers. You can see it on, if you if you go night hiking on some of the trails in Griffith Park, you'll sometimes come across a Western toad. But there would have been 1000s uh, not that long ago.

Marcos Trinidad 7:25

You just painted a very different picture of what most folks think of LA. I mean, we had all these native species around. So what changed?

Dr. Greg Pauly 7:35

What really sort of happened- The human population dramatically increased through the late 1800s and early 1900s. We have this huge flood in 1862, largest flood in history of California. For 28 days straight, we had rain. During that flood the the LA River, Santa Ana River and San Gabriel River in their lower stretches, they overflowed their banks, and they basically created an 18 mile wide sheet of water flowing across the landscape, like this totally devastating [Marcos: Wow.] situation. You have multiple big floods in, throughout LA's history, like huge portions of present day LA would be destroyed. If you actually look at like the archaeological record, and where the Tongva and the Chumash were setting up um, their communities, nobody's building like right along the LA River. No one's building along the lower reaches of the San Gabriel River. There was seasonal activity there. But they're not building there. Because that's like, they've seen the floods, you know? Um, and so it's not until you really get sort of the increasing build up of the city of Los Angeles itself, you know, close to the river, that we really have the loss of human life and the loss of structures in these big flood events. Um, and then the solution there isn't, okay, well, maybe we should build elsewhere. The solution was, well, you know, we can control nature. Like we can, we can channelize the rivers, we can bulldoze over the landscape and, and sort of modify this habitat into, you know, whatever we wanted it to be.

Marcos Trinidad 9:04

Can you explain what channelizing the river is?

Dr. Greg Pauly 9:11

Yeah. So there was a need to control the flows in these rivers and channelizing simply means trying to, you know, create a situation where the water can easily flow down the river channel. And the most common way to do that is to straighten out the channel so that there's not a bunch of bends um, and to remove a lot of the vegetation, so that that's not holding up water. And the the standard way to do this is you just take a whole bunch of concrete and take a whole bunch of cement and you basically just line the river in concrete.

Marcos Trinidad 9:43

Did we get the changes that we wanted from channelizing the river, like was it uh, effective?

Dr. Greg Pauly 9:52

Channelizing the river was certainly effective for a small number of goals, so it protected human lives, it protected property, it allowed development in areas along the river um, because people could develop there without the fear that it would be taken out. And so that goal of trying to channelize the river and try to kind of take control of sort of the impact of water, you know, on the development of the city, that that goal was certainly met. But the long term consequences, I think were not fully appreciated at that time. If we're living in a situation where, where water is something that we're kind of desperate for and that's our situation, what do we do with the water that does land in this region? We get the water out of the urban areas out into the ocean as quickly as possible. Yeah, we're, like totally desperate for that water. So [Marcos laughs] we've done a really,

Marcos Trinidad 10:47

And then we import water.

Dr. Greg Pauly 10:48

Yeah! And then we have to bring in water from the east side of the Sierra. And we have to bring in water from the Colorado River, because our actual water that lands in our region, we shunt off to the ocean as quickly as we possibly can. You know, we need to be keeping more of that water on the landscape. And so I think on the short term, absolutely, channelizing the river worked. Long term, this is not going to be a sustainable solution for Southern California.

Marcos Trinidad 11:13

How did that landscape change impact the wildlife?

Dr. Greg Pauly 11:18

Yeah, I mean, it's, this is a completely different place from the perspective of wildlife. Um, for frogs, the habitat wasn't necessarily the river channel, it was the backwaters, it was the side channels. And so when we channelized the river, what we really did is we allowed those other areas to then be developed. But even now, actually, if you go to the LA River now, or you go to parts of the San Gabriel River now, the flows are actually too strong for frogs to really make it there. So even something like our non-native bullfrog, which is this, you know, horrible invasive species, like, I mean, they're cool frogs, as you know, we went and caught some. But even the bullfrog, which can make it in a tremendous variety of habitats actually struggles to make it [original music] in the LA River. And the reason for that is that there's not enough places to hide. There's not enough habitat complexity. When we get a big springtime flow of water or wintertime flow of water, you know, those tadpoles that are, the few tadpoles that happen to be in the LA area, you know, they're all getting washed out to the ocean.

Marcos Trinidad 12:20

When we come back, we'll head out to a creek to visit this tenacious little frog that's still making a living on the west side of LA. [music out] [break]

Marcos Trinidad 12:29

[ambient urban outdoor sounds] Back out in Playa Vista with Greg, we head across the street from that park pond I told you about. We want to check out a little slice of native habitat called Bluff Creek Trail. [sound of someone jogging] We're here in the evening. Joggers are out, and the lights are just coming on in the houses on the top of the bluff.

Dr. Greg Pauly 12:53

You actually have this really beautiful coastal sage scrub habitat running up the bluffs.

Marcos Trinidad 12:58

At the bottom of the hill is a stream and hiding in the cattails is an OG LA frog species. [frog calls and crickets]

Dr. Greg Pauly 13:06

Oh, we're starting to hear 'em.

Marcos Trinidad 13:07

The Baja California tree frog. [frogs grow louder]

Dr. Greg Pauly 13:11

Hear the ribbit, ribbit, ribbit? [a frog calls loudly] This is the only frog in the world that actually says ribbit. [Marcos laughs softly]

Marcos Trinidad 13:20

Greg says it's call ended up in movies, and the 'ribbit' got famous.

Dr. Greg Pauly 13:25

And what we're hearing is the advertisement call, the mating call. And the main difference, the main thing that we know varies is frequency, and frequency in most frog species is correlated with body size. And so females are listening in to that frequency and deciding whether or not that frog is sort of the right size, the right shape for [Marcos: Wow.] what they're interested in.

Marcos Trinidad 13:47

But spotting the tree frog is tricky because they want to be heard by all the ladies, but they don't want to get chomped on by a bullfrog. Most of the frogs are hiding deep in the cattails. So that means we got to suit up in thigh high waders, basically waterproof overalls and go and get our feet wet. [bubbling sounds] [crickets and frog calls] Bubbling up from the mud is gas made by decomposing plants, which smells like rotten eggs. And since we're stooping over the water's edge, we're getting a huge whiff. But eventually that's all worth it. [frog call]

Marcos Trinidad 14:26

There's a little one. It just jumped! It was so little. [sounds of footsteps in cattails] Okay, I got him. [female voice, laughing: Oh no.] Oh, he's so little!

Dr. Greg Pauly 14:40

Oh my gosh. [footsteps] [frog chorus]

Marcos Trinidad 14:44

Okay, cool. So you just pulled out a Ziploc. [Dr. Greg Pauly: Yeah, so.] Ziploc bag and grabbed [Dr. Greg Pauly laughs] some of this delicious water.

Dr. Greg Pauly 14:53

Yeah, some not exactly crystal clear water. Uh, and what we're looking at is, that is our, it's a relatively small Baja California tree frog. This one's probably three to four weeks old.

Marcos Trinidad 15:08

It's a khaki color frog about the size of your pinky fingernail. With that one in the bag, we keep looking. A couple of minutes later, we got a bigger one, about the size of a quarter. This one is light green with a dark stripe over its eye. And the skin under its chin was sort of saggy.

Dr. Greg Pauly 15:26

So this is definitely an adult male. And his vocal sac was extended enough that he's definitely been calling tonight. We'll probably release him and within 15 minutes, he'll probably be calling again.

Marcos Trinidad 15:36

This chorus is actually louder than it would have been a few years ago. Conservationists have been removing bullfrogs that may have snuck over here from the park pond. With those predators gone, the tree frogs have had a chance to recover. But Greg says back in the day, this frog party would have been something else.

Dr. Greg Pauly 15:56

[loud frog chorus] You could have stood up on the bluff that's right behind us right now. And you would be hearing frogs calling, you know, 50 feet away from you and you'd be hearing frogs, you know, a quarter mile, a half mile away. You would just have a deafening chorus of frogs.

Marcos Trinidad 16:09

A healthy population a tree frogs is [original music] something we should want in our city. And not just because they eat mosquitoes.

Dr. Greg Pauly 16:18

I think most humans, if you took them out and they were standing in a wetland in the middle of a frog chorus, this total biological spectacle, they're forever changed. Like it's just this amazing bit of our natural world. So I think that alone, like I think your life is better off experiencing lots of nature. Um and studies show this, mental health studies show this, physical health studies show this. Like this, this is, this like all totally true. But like you don't need to read a scientific study, like just go you know, spend an hour around a bunch of calling frogs, and it's like, nobody walks away from that experience and thinks, man, I wish I was just playing an arcade game. [music out] [Marcos laughs] You know, they're gonna like walk away from the experience and be like, this is one of the best nights of my year. [Marcos laughs and says:Yeah.] And it's just, it's an, you know, it's an amazing thing to experience. And then to know that there's only a few pockets around LA where you can like, go out and experience a frog chorus now. Whereas, you know, 150, 200 years ago, there was like, you just like, you'd be inundated. If you were in the LA basin, if you were in like in the coastal LA basin, like, A: you could barely move around, because there was, you know, marsh everywhere um, in the spring and early summer. But like, if you were in that habitat, I mean, you and I wouldn't be able to have a conversation. It'd be too loud. We'd be screaming at each other to be heard.

Marcos Trinidad 17:39

So what would your vision of a reimagined LA habitat that works for humans and and wildlife species, what would that that look like?

Dr. Greg Pauly 17:52

On a per person basis, water consumption needs to drop dramatically. We just don't have enough water coming into Southern California to justify um, the current levels of water use. It's time for every time you see a lawn, you just need to feel sick to your stomach. Like unless you have, unless you have a dog that needs a spot to poop or a child that needs like a couple 100 square feet to play, you know, if you have a lawn for soccer, or something like that, that's fine. But otherwise, if you look at a lawn, you should just be like, ah, that's so gross. Like what a horrible thing to do to the landscape. Lawns are, basically have the same biodiversity value-- This is a little bit of an exaggeration, but not much. [Marcos laughs] They basically have the same biodiversity value as a patch of concrete. But if you ripped out that lawn and you put in, you know, sages, buckwheats, you know, Manzanitas, things that are climate appropriate and beautiful. I mean, let's just load up on lavenders. I mean, who doesn't like a lavender? I mean, they're just beautiful. [Marcos laughs and says: Right?] They're attracting all sorts of native insects, like it is so welcoming to biodiversity. You know, suddenly you'll have a yard that's full of native bees, you'll have a yard that's full of native flies, you'll have a yard that's welcoming to lizards. Lots of birds will be showing up. Um, you know, you can have this absolutely amazing habitat. And if, you know if, if people started doing that all across LA, wouldn't it be amazing if that's what our landscape looked like? And the thing is, is like I mean, lawns have tremendous maintenance needs. So like if you plant you know, a bunch of the plants that you know, sages, buckwheats, etc, the maintenance needs are really low. So it's actually like, better for the environment, better for wildlife, easier for maintenance. And if you don't have a lawn, you know, if you live in an apartment or you live in a condo or something like that, no big deal, like the same is true. You can put a sage or a buckwheat or a lavender in a potted plant, and that that act alone is going to welcome more biodiversity.

Marcos Trinidad 19:45

So can we remove the concrete or the cement to restore some of these habitats?

Dr. Greg Pauly 19:53

Yeah, I mean, I think we have to be realistic about what can be done. Like, we can't just say, Well, we're gonna rip out the concrete and and let the river do its thing because the river would be flooding neighborhoods. I mean, you know, if we had if we had something on par with like, you know, some of the floods in the late 1800s, early 1900s now, I mean, we'd lose, it'd be billions of dollars in losses. It'd be 1000s of human lives. So like, we can't just, we have to be realistic about what's doable in the in the current landscape. It's not that we got to this stage overnight. It took, it took decades to kind of get to this stage, and it's going to take decades to get out of this. And so, at the local level, I think the answers are easier. You know, we need to be thinking about um, you know, local stormwater solutions where we're, we're not letting that stormwater runoff into the LA River. You know, part of the reason that we had those floods is also that, you know, we paved over the landscape and so instead of, you know, if a water droplet, you know, falls in Burbank, that water used to be able to per- you know, percolate down into the ground, but but now that water's you know, hitting asphalt, hitting sidewalk, hitting a driveway, is flowing into a storm drain and flowing into the LA River. So we need to do things like at the local level, we need to stop letting that water run off the landscape. You know, there's no reason that your gutters around your roof should be shunting water onto your driveway that flows down into the storm gutter. You know, you can absolutely be containing some of that water, and then using it for irrigation so that instead of using, you know, Owens Valley water or Colorado River water, you're actually using water that fell on your exact location. [original music] I hope people recognize that decisions we make now are absolutely going to make a difference on what are the species that we're seeing across greater LA, five years from now, 10 years from now. What are the species that our kids are going to see, you know, in the next generation. Like, I hope people feel empowered by that message.

Marcos Trinidad 21:48

Greg, I appreciate all your time. Thank you for coming on the show.

Dr. Greg Pauly 21:52

Oh, thanks for having me. Thanks for coming out and looking for frogs. That was a total blast. Take care.

Marcos Trinidad 22:01

If you want to see this kind of marshy habitat of historic LA, Greg recommends Ballona Wetlands, Gardena Willows, and Madrona Marsh. And I understand. Now that you've heard a sample, you might want to catch your own personal frog concert. Well, from now until September, if you visit a local stream right after sunset, you might encounter a frog chorus. Greg says you'll have the best luck on a June gloom kinda day, or even better right after a rainstorm. But if you want to be extra sure of a sighting, you could cheat a little bit. You can browse the iNaturalist app to see where other people are recording frogs around you. That goes for people in LA and across the country. And if you want to help out your local frog species, Greg says you have his permission to start hunting bullfrogs again. All you need is a fishing license. [music out]

Caroline Champlin 22:58

[theme music] Human/Nature is hosted by Marcos Trinidad. This episode was produced by me, Caroline Champlin, with help from Carla Javier. Fiona Ng is our acting supervising producer. Mixing and engineering by Parker McDaniels and Shawn Corey Campbell. Ex Manana composed our music and Doris Anahi Munoz is the music supervisor. Human/Nature is a production of LAist Studios. The marketing team created our branding with art by Christine Tyler Hill. Special thanks to Taylor Coffman, Sabir Brara, Kristen Hayford, Kristen Muller, Andy Orozco, Michael Cosentino, and Neha Shaida. Antonia Cereijido and Leo G are the executive producers for LAist Studios. Our time in the field was recorded on Gabrieleno Tongva Territory. Support for this podcast is made possible by Gordon and Dona Crawford, who believe that quality journalism makes Los Angeles a better place to live. This program is made possible in part by the Corporation for Public Broadcasting, a private corporation funded by the American people. That's all for this episode of Human/Nature. We'll see you next time. [music out]

Transcribed by https://otter.ai