Armchair Expert with Dax Shepard - Flightless Bird: Callery Pear Trees

Episode Date: February 6, 2024

This week on Flightless Bird, David Farrier tries to understand why his entire street smells like semen. He finds himself in the world of the Callery Pear Tree - also known as the Linden Tree or the Bradford - AKA “the cum tree”. David talks with Theresa Culley, a professor at the University of Cincinnati - who knows a lot about this particular foul-smelling tree. The plant biologist teaches David why the trees smell like that, before diving into an analysis of how American these trees really are. David is shocked to find out one of these trees survived 9/11, and is now found at the 9/11 memorial site. He also discovers the tree - once the darling of US landscapers and gardeners - is now considered an invasive species. With this in mind, David visits LA’s Natural History Museum to meet herpetologist Greg Pauly, who educates David about some of America’s other invasive species, including one particularly loud and annoying frog. Learn more about your ad choices. Visit podcastchoices.com/adchoices

Hi, Flightless Birds back. Hey, Monica. Hi. We took a little breaky break. That's how they say it in New Zealand. That's how they say it in New Zealand. We always say breaky break. Yeah, I went back to New Zealand, had a little holiday. Sometimes you've got to have a little holiday. You've got to recoup. You've got to relax. And I know you haven't had any Flightless Birds to listen to, but that's the news today. We're back again with a very American episode. The most American. Probably the nastiest one so far.

Yeah, it is. It's nasty. It is nasty. But it's a great way to start 2024. We want this year to be nasty. Yeah, and we want it to have like a certain scent. We want it to have a certain smell. So get ready. Get ready for this episode. And yeah, welcome back. Flightless Birds back every week, every Tuesday. Enjoy. I'm David Farrier in New Zealand, accidentally marooned in America, and I want to figure out what makes this country tick. Since I've been in America, I've tried to experience America in as many ways as possible. And not to state the obvious, but I've been using my senses to do so. Often in this podcast, I'm describing what I'm seeing, the juicy hot dog on my plate,

or the pizza fresh out of the oven. So much of this show is just people describing the America they see with their eyeballs. Perfect thin slice with the perfect crust, excellent sauce to cheese ratio. It's amazing. You can see how like the sauce bleeds through just slightly. My experience of America also involves me listening. It's a lot of sound, sort of important for a podcast. Every episode, we're recording what we hear before playing it back to you. The gentle sounds of the Everglades or the loud assault of a leaf blower and me getting annoyed at it. I'm not even by the window anymore, I'm sitting at my desk, trying to work. Ah! Stop! Chloe!

As I see and hear things, I often forget about the other main way in which I experience America. Every day. By smelling it. And there are a lot of smells that make up the United States. Be it the wonderful, warm smell of an apple pie fresh out of the oven. Or the rancid, rotting stench of trash bags piled high on the sidewalks of New York City. I guess smells are difficult to portray in a podcast, and to be fully effective I'd have to come to you and spray various smells in your face, which no one really wants. But today's episode is important, because it is about a smell.

A smell that's been bothering me since I got here. Not all the time, not every day, but for about one month every year during the spring. It's the smell of semen, and it hits my nostrils without warning. Because as the calorie pear tree blossoms on the street outside my apartment, and in the park down the road, and outside my friend's house, the distinctive smell is spread all around the city, invading my nostrils, causing me to instinctively flinch. Some call it the Callery pear tree, others the linden tree, or the Bradford, a tree that comes in many cultivated forms with many cultivated names, but it all comes back to the same foul smell of jizz.

So prepare to have your nostrils assaulted by one of America's most popular perennial plants, because this is the same page in the room. Have we all smelled this tree? Yes. I'm curious how many people know it as the calorie pear tree. I've only heard Bradford pear. Just Bradford pear. I don't know what you're talking about.

No idea. No idea what you're talking about. You've never smelt the smell? No. Well, I've never associated a tree smell with the smell of cum. Right. Have you ever smelt that smell out and about and just not wondered what it was? Thought it was trash maybe? I don't know that I know what cum smells like. Okay. Well, let's just, okay They were outside of my school Okay My high school And yes, it's impossible not to recognize that it's It's there

A foul odor And before I knew what cum smelled like What that smell was We all said it was period smell Okay, right So, I mean, still like this horrible, disgusting, like bodily smell. Yeah, something sort of off somehow. Yeah, I mean, I was like, oh, period trees are in bloom.

Oh, so you call them period trees? We did. Me and my friends did. Right. And then more recently, I was with people and then they refer to it as semen trees. Right, and you're like, oh. I'm like, oh yeah yeah i guess it's also that obviously these are found all over the world it's not just in america but america has

really embraced them because they're a pretty tree beautiful white flowers really nice but the smell seems to counter anything that's why i'm so fascinated by this why did this tree take off here when the smell was so bad? There's looks and there's smell. And in my mind, smell always takes over from looks. Well, sure. In a person. Think about it in a person. If there's a gorgeous person.

Beautiful. Beautiful. Handsome. The most. And yet, if they are horrifying smelling. Well, say they smell a bit like semen. Okay. For instance. Yeah, just a little whiff now and then. Well, say they smell a bit like semen. Okay. For instance.

Yeah, just a little whiff now and then. Oh, wait, no. It can't be now and then. It has to be like repugnant all the time. Okay, so it's all the time. What do you do with that? Would you want to be near them? My smell is so, I don't think I could.

I think my smell overrides most other senses. And it's one of those things, if there's a smell, it your brain it takes over i think i'd really struggle same smell for me is the the most well it's one of the biggest things it's one of the biggest things but it also is an indicator of attraction i think so like with pheromones and things like that so if i don't love the way somebody smells it is a deal breaker. If they lay it up with enough deodorant or cologne. Yeah. Covered it up.

That might be possible. So you just know in their natural showered state, it's going to be bad. But as long as they cover up, it's okay. How does that go? That's hard for me. It is difficult, right? You should come back to this. And it's hard for the Bradford bear.

I looked up what the smell of semen is because it's often ammonia, bleach, chlorine. That's kind of like the kind of smell it replicates. So this website, Healthline, semen's about 1% sperm and 99% other compounds. Many of the substances in it are alkaline. So they're above 7 on the pH scale. And some alkaline substances in semen include magnesium, calcium, copper, zinc, sulfur. So you're getting all sorts of things in there. Zinc, that's healthy.

And all this tends towards slightly alkaline. And that gives it that kind of ammonia-y, bleach-y kind of a smell. Yeah. Vaginas have more of an acidic nature to them. Yeah. And so sometimes when the acidity of the vagina and the alkaline nature of semen come together, all sorts of crazy stuff can happen.

Like? Just different smells. Oh, different smells. Different smells. Yeah, it gets crazy. What about buttholes? What's their alkaline? I haven't gone into that.

That's a different episode. Buttholes is a different thing. Well, semen interacts with people's buttholes a lot. It does. It does. I don't know the exact chemical compounds and the exact smells, but I can look into it at a future time. I think there's some private Googling for you to do. I feel like we're out of the remit of the show. Where did you first smell it? I want to hear your first experience. It was on my street. So I live about five minutes from where we're recording right now.

And I just walk out the door and it just, yeah, it hits and it hits hard. And I didn't know what was going on. It's like, why is there so much semen around? It was a panic reaction. It was like something has happened. The first time you smelt it, it was immediately semen association. That's why I'm so surprised you missed this. I agree with David.

It's so undeniably like a bodily fluid. Yeah, that's what it is. And it's so common in Los Angeles and all around America, like Georgia. I would say, though, I smell it way more in Georgia than I do here. So I'm kind of surprised that you have smelled it here. I think I just happened upon a street that has a lot of linden trees. And so it was just purely luck. Okay. Are you going to get into any of the geography oh yeah we're gonna go deep well it sounds like maybe i don't want to

associate the smell once you smell it you can't unsmell it you can't not smell it like i just making that tie you can't not make the tie it's gonna hit you i'll bring you a little calorie pear tree for christmas and you can pop it in your yard for your landscaping. And you can experience it every day when you walk out the door. Yeah, it is a pretty tree, but it's not the most beautiful. I agree. That's why I think it's crazy. I mean, that's the whole impetus of this episode.

Why did this tree take off here so much? Horrible. It is. The first time I smelt it, I wasn't quite sure what was going on. I'd stepped out of my front door and was hit by what you're often hit with in LA, a dry wall of heat.

Then something else struck me, a smell. I'd smelled it before, but this was somehow stronger and it was everywhere. It was overwhelming. From what I could tell, it was emanating from the blossoms of the trees lining my street, which was confusing because flowers are meant to smell, well, flowery.

I wondered if something was going on with my nostrils, my sense of smell, maybe a new strain of COVID. So I went over to see my friends Ben and Rachel. Rachel grew up in California and Ben's from Iowa. Between them, I hoped they'd have some answers. Tell me about this tree that smells like jizz. We had them all around our high school courtyard. So when we'd be walking to classes or at lunch, we'd just have to sit amongst that smell all day. And was that just normal or was it talked about? Both. Our teachers would often remark on how bad it was, but we just dealt with it. And I think they were all around the city as well, but like they were really concentrated in that

middle part of the school. And how would you personally describe the smell? Extremely semen-like. The tree is the Pyrus caleriana, aka the calorie pear tree, also known as the linden tree. Ben chimes in. I think Rachel has a much more sensitive sense of smell than me. I think Ben is not perturbed by the smell of semen is what I think. It's just on your hands constantly. Yeah, it's just I'm already so inundated. I'm smelling it

constantly. Or it's like when you live next to a waterfall where you don't notice the sound anymore. I don't notice the smell of jizz. Since talking to Ben and Rach, I've talked to a lot of people about the linden tree. and the conversations often go in this direction towards some kind of juvenile humor. I mean with that smell in the air how can it not? I stumbled on this old sketch from comedians David Mitchell and Robert Webb. That show was called the Mitchell and Webb look and being British it was a pretty popular show in New Zealand. We love British things in New Zealand. Anyway, in this one skit they did, it's the year 1880, and an American general is presenting a visiting Queen Victoria with a tree

to take back to England. This, your majesty, is the linden tree, which has long stood as a symbol of the loyalty and strength of our people. The queen looks at the tree, sniffs, and then looks pertur No, it is not me, your majesty. But I don't really, I mean, I can't say I really smell. Oh, you must be able to. It's potent. Revisiting this sketch did two things for me. It made me feel less insane, and it also seemed to indicate that America was possibly the country responsible for this tree. But I'd need to look further than a sketch comedy show for answers. I'd need to talk to someone who knew what they were talking about. My name is Teresa Cully, and I am a professor at the University of Cincinnati,

Department of Biological Sciences, and I'm a plant biologist. I study pollination biology and population genetics of plants. I'd come to Teresa to get answers about what I'd now termed the cum tree, although she describes the smell in slightly different terms. She's got more class than me. I don't know about you, but they smell horrible to me, like wet socks or a dirty cat or a dog. Before finding out how American this tree was, I needed to find out why it smelled so bad. And as the smell of semen might suggest, it's all to do with procreation. The answer to your question about the smell is that the plant itself is trying to attract pollinators. So it releases

chemicals into the air. So they're attracting pollinators which come in, move the pollen from one plant to another, the plants produce fruits, and then the other part of it is that birds have to disperse the seeds later in the winter. And at least in the Midwest, what we've been seeing is European starlings that are primarily eating the seeds, flying elsewhere, and then they defecate them out, oftentimes along the telephone lines or electrical lines along the roadways. And so that's why you see them popping up there along the roads. So insects love the disgusting smell of the flowers, come in and grab the pollen to pollinate other trees,

which means the tree can grow fruit which contains seeds. Seeds which then get spread around the place by birds and grow more smelly trees. Although for birds, this tree tends to be a last resort. So what you'll see oftentimes is a lot of the birds just avoid the callery pear trees in fall and early winter. And they only go to them at the very end of winter when it's the only thing left over. And so they actually, we think, prefer other plants and their fruits, but they'll make do with calorie pair if it's the only thing around that's so funny so insects absolutely love it birds are a bit more 50 50 on it yeah exactly stay tuned for more flightless bird we'll be right back after a

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What's a jersey? A jersey is a sweater. A sweater? Yeah. Not like a sports jersey. No, no, no. So when I say jersey, I mean sweater. Okay.

Upgrade your closet with Quince. Go to quince.com slash bird for a free shipping and 365 day returns on your order. That's Q-U-I-N-C-E dot com slash bird to get free shipping and a 365 day returns. Quince.com slash bird. quince.com slash bird. I found myself wondering why insects would be attracted to a gross-smelling flower in the first place. Like most flowers smell good to humans and to friendly pollinators like bees. I wondered what the evolutionary advantage was to smelling absolutely disgusting.

That's a great question. Flies, for example, they're pollinators and people don't think about that, but they tend to go for things that smell rotting. Flies. Flies like weird smells, rotten meat, dead animals, semen. Until now, I didn't even know flies pollinated anything. I just assumed they were here on the planet to annoy humans. But of course, they're involved in the life cycle of the Callery pear tree. With the question of the smell mostly answered, as well as how the smell helps it spread around the United States, I needed to figure out how American this tree was. I mean I know it exists in other countries, I think I've sniffed it in Australia. At least I hope that's what I was sniffing.

But why is it so prevalent and popular in America? At the time in the United States, in the early 1900s, there was Pyrus communis, which is the edible pear that we normally eat, the Bartlett and so forth. And there was huge plantations of it, largely on the West Coast. And a fire blight, a bacterial infection, actually attacked the normal trees that people would use to produce the pear fruits that you would buy in the store. And so the USDA, the government, decided that they needed to send

plant explorers over to China to find a related species that was immune to this disease, with the idea they can bring back that species and breed it with our normal pyrus communis and create a plant that wouldn't get the disease. So what they did was they sent several plant explorers. The most famous is Frank Meyer. He would just send back bags of these seeds and they would plant them on the West Coast and then the East Coast in Glendale, Maryland, and they would grow up the plantings and test them for fire blight and so forth. So that went on for a few decades. Then around, we think of the 40s or 50s, there was a huge group of these trees growing in Glendale,

Maryland, by the USDA station. And one of the directors saw what he thought was a really attractive tree because it had these white blooms in the early spring. And, you know, it was growing larger. So he set it aside and was protecting it. And so he actually started to propagate it. And so what he would do is he would cut off some of the branches. With plants, you can actually graft two plants together. And you can't really do that with animals.

And then he would graft it onto the bottom of another plant. And he planted them all in the neighborhood around the station, and people loved them. And they thought they were beautiful. They bloomed in the early spring. And so that was the Bradford. And the Bradford was the first cultivar, cultivated variety, Bradford was the first cultivar, cultivated variety of the calorie pear. And so that was sold first in 1961. And people loved it. So to recap, in the 1900s, the United States Department of Agriculture sent some plant explorers, yes, that's a real job, to China to find some kind of pear tree that would be hardier than what America already had.

A bunch of seeds got sent back from China, they were planted, and during the 50s, one in particular looked quite good and was pampered and cultivated and finally sold commercially in 1961. People loved it. Everyone wanted it. They saw their neighbor had one, they wanted one. And so the plant breeders and propagators just started propagating this Bradford tree. But the interesting part is all Bradfords, even today, are all genetically identical. And they all come from that original tree from Maryland. And they just cut it and propagate it. And people have talked about this as an army of clones.

It's hard to describe how fully on board America was with this army of foul-smelling clones. Former First Lady Burr Johnson promoted the tree in 1966 by planting one in downtown Washington. And I've been going through old copies of the New York Times, and on January 5th, 1964, the paper wrote a report on the Callery pear tree. Except it reads less like a piece of journalism and more like a giant commercial. Homeowners, especially those in new developments, are concerned about improving their properties with trees that are not only suited to the existing site and climate, but also to the individual style of home architecture. Few trees possess every desired attribute,

but the Bradford ornamental pear comes unusually close to the ideal. The article isn't short either. It goes on and on. Leaves of the Bradford tree are similar to those of other pears. They are thick, a glossy deep green. Wavy edges cause them to quiver and reflect the sunlight during the lightest summer breeze. The New York Times talks about the leaves and the bark and the blossoms, but at no point does the New York Times state that this tree reeks to high heaven. Just rewind. So this original Bradford that everyone got so excited about, did it have the smell?

Yes. No one noticed this and went, there's a slight problem. We love the look of the tree, but this is an issue? Or did no one care? I think at that time they didn't care. They were so intrigued by the beauty of the tree. It's one of the first that blooms in the early spring. And if you have one tree, you may not notice the smell. The smell has always been there.

It's just now when you have lots of them, you have a patch. You really smell that. So back in the 60s and 70s, no one cared about the smell. But people, sellers, growers, city planners, did start to notice another problem with the Bradford pear tree. A big one. Turns out in bad weather or over time, the smelly tree tended to sort of fall apart. It grew easily in lots of places, but it was also kind of weak.

Now, if evolution had its way, I wonder if this could have been the end to the cum tree. But America had already made up its mind. It loved the cum tree. And so it would simply modify it, make it harder, better, faster, stronger. So a bunch of other calorie pear trees were developed. We have the aristocrat, the Cleveland Select, the Chanticleer. All of these, they're genetically different from the Bradford, but they're all the same species. How many variations are there roughly of this Bradford?

I think there are at least 70 different cultivars of the Bradford. There are new ones that are still being developed. So really America did create the perfect tree. They really put effort into making this thing perfect and solidified it here in the States. I would say yes. And what they did, though, it wasn't any fancy genetic engineering or anything like that. They just selected what we call genotypes, genetically different individuals that just happened to grow well and look beautiful. But it turns out all these genetically different smelly trees created a new problem that no one had the foresight to see. A problem that I had no idea about until now.

When everyone was planting just the Bradford, I told you how they're clones. It's all the same thing. So it didn't produce any seeds. But then when people started to plant new cultivars, the Aristocrat, chianoclear, and all autumn blaze and all that, suddenly they can cross pollinate. And so now pollen's all moving around and suddenly all the trees can start to produce fruits. Now we have all these clones of different clones sharing pollen. And so now they're producing fruits. And the fruits are not like the big edible pears. They're just small marble size pears. And they have anywhere from two to 10 seeds in them. And the birds love those. The birds just feed on them, fly away, deposit them elsewhere. And so that's

why they're spreading. Each cultivar technically is incompatible. It can't produce seeds, but you get another cultivar together and now they can just cross pollinate and you got problems. A problem in that this once loved American tree is now listed in many states as an invasive species no longer welcome here. The cum tree, a tree brought to America by the USDA, is now considered a pest, not for its smell, but for its ability to breed out of control. Like the female dinosaurs in Jurassic Park, life had found a way. So what we're seeing right now in 2023 is that the species,

if the seeds get out, it forms a huge monoculture. It's a thicket, really. And many of these trees actually revert back to how they used to grow in China. They have what we call thorns. They're technically spurs, but they're thorny. And people don't like that. There's also evidence now that the tree is allelopathic, meaning it's putting chemicals into the ground and it inhibits other plants from growing. Now in 2023, a lot of states are actually beginning to ban the commercial sale and distribution of the calorie pear. Ohio was the first state to ban the calorie pear tree, and other states are now following.

Pennsylvania has it on their noxious weed list, so it can't be sold anywhere. And South Carolina will be banning it in the next year. Turns out one of America's favorite trees is now on its most wanted list. And not for its smell, but because it became a victim of its own popularity. All this is so crazy to me. So there's this disgusting smelly tree that America specifically bought in from China

because it needed like a strong pear tree. They like the perfect tree like cultivating it up making it perfect spreading it around selling it in nurseries now it's breeding it's out of control and it's screwing up the soil in the united states like it's poisoning the soil it's leeching in horrible semen everywhere yeah but it's a good metaphor for masculinity. Yeah, I agree. Just taking over. Out of control, taking over. Absolutely.

Horrific. Horrific, yeah. Yeah, just can't stop. Breeding out of control. Awful. Causing problems. Causing problems. Mixing with poop.

Yeah, I just had no idea about any of this. And I just happened to find that Teresa is just this expert on this tree. She loves this tree. She's so brilliant. She's pretty incredible. She knows everything about this. I love it. But it's terrifying because if this goes on, they've had to ban it in some states. Some states are banning leaf blowers, right? They're like getting onto the problem. Some states are banning this tree. But how can they ban it if it's just birds are dropping? Well, those things, it's just they can't? Well, the thing is just they can't sell more of them. Although some states, you are encouraged to chop them down. So if you have them

in your yard, you just chop the whole thing down. That's how out of control it is. If this goes on, eventually the entire United States will just smell like jizz. That's what it's heading towards. I'm not joking. Okay. Also, it is so funny when the schoolyard seems to be oh Rachel and Ben mimicked exactly your experience right so weird sitting in the schoolyard trying to eat your lunch smelling this shit oh it's kind of unifying it's like every American kid can understand except Rob I guess although you're banned his argument of not smelling is just He's so used to the smell of semen he doesn't smell it anymore Maybe I am

That's an awful fact about you But one we just have to live with That was an astute thing That he said because I think there is Absolutely no way You haven't come across one Yeah I'm not saying that I'm just saying I haven't made the connection

In my brain that those smells are connected or maybe my semen just smells different it's possible no but you're not even recognizing that there's a tree you would know that oh yeah there's a tree sometimes i smell that's horrific even if you're on the street you must smell it plants that don't smell great no you've never left the house and smelt cum everywhere. It's like it hits you like a truck. No. Wow.

Some people don't find it unpleasant. Some people like the smell of it. I don't like the smell of it. Some people maybe like the smell and Rob might be one of those people, which is fine. Certain men take women over to those trees and they're like, do you like this? As like a litmus test, like how horny. I hope not. I bet that happens.

Seems like a Harvey Weinstein type thing to do. Oh God, it'll exist. Yeah. If you have anyone in your life that's done this to you, please DM us. Please wink twice. I want to hear about this. Okay, so this story gets more intense.

Are you ready for more intensity? Yeah. Because this Callery pear tree is at the heart of the United States. It's crazy. I missed why it's called calorie pear because she has said Bradford a ton. And then why is it calorie pear? Oh, it's from its scientific name.

Oh, okay. Like genus and species. Yes. So the Latin name, which I will screw up, is Pyrus caloreana. Oh, okay. Okay. Okay. So it's just shortened from that.

Got it. But it is crazy having so many different names for this one thing. Gets very confusing. Okay, shit's about to get crazy. Oh. Realizing that the Calorie pear tree was an invasive species had me wondering what other invasive species had invaded America. Teresa had told me about some others, plants like Japanese honeysuckle.

But of course, there are animals too. So before I wrapped my journey into the Callery pear tree, I wanted to find out what America's other big invaders were and what they smelled like. I'm going to start with a very simple question. I just love your name and what it is that you do. Greg Pauly, and I'm the curator of herpetology at the Natural History Museum of Los Angeles County. We're in the bowels at the Natural History Museum of Los Angeles County. We're in the bowels of the Natural History Museum.

And like the basements of most museums I've been in, it feels sort of chaotic. Corridor after corridor, leading to offices and workspaces and giant storage areas with those huge shelves on rollers that store the stuff not on display at the museum. Now, on the journey I've been on investigating this very smelly tree, I've learned that America has a lot of issues with invasive species in the plant world, but I also hear in the animal world as well. Yeah, there's quite a few non-native species, some of which have become invasive, and it's true for plants, and it's true for a huge variety of animals, and it's continuing to happen every single day. Of course, there's the issue of things coming in from overseas,

but also just things moving between the 50 different states as well. One of the challenges in the U.S. is that you have this really big country that has places like Florida and Hawaii and Puerto Rico that have these very tropical climates. They also have, especially Florida and Hawaii, have a major nursery trade. And so non-native species get established in these pretty easy-to-get-established places because there's lots of water, you don't get hard freezes. And then we're exporting thousands and thousands and thousands

of shipping containers full of plants from Florida and Hawaii. And in those shipping containers are all sorts of non-native species of which we are only detecting a tiny, tiny number. And the ones we're detecting are these agricultural pests, but lots of other stuff is getting moved around at the same time. And so that's a particular problem in the U.S. just because we have this huge variety of states with differing climates. Is there anything in particular that's gotten out of hand

at the moment that you find interesting? There's this little tiny frog called a coquifrog, and it's getting moved around in the nursery plant trade. So it went from Puerto Rico to Hawaii. And the reason that happened is because in Hawaii, some hotels in the 80s wanted to have lush tropical plants. And instead of using lush native Hawaiian plants, they imported plants from Puerto Rico.

Minimal biosecurity, coquifrogs come along. These little tiny frogs make a huge amount of noise. The result is that as they spread, property values decrease because people didn't want to live around them. And now that they're established in Hawaii, they're getting shipped with nursery plant shipments here to Southern California. Right. So they're slipping in on these plants. Yeah. That's happening on a regular basis. yeah. Once they get established at a nursery, then they can show up at lots of other places. So I've had people who have bought plants at Home Depot who then have a frog hanging out on their plant. It decides it likes the conditions on their patio, and it starts calling loudly, and people start complaining from multiple houses away.

Because all of a sudden, there's this frog that's making these calls all night long. Tiny frog, massive mouth. It's totally impressive how loud they can be. I wanted to hear what the koki frog sounded like, but the only frogs at the museum were dead and in jars. Not much good to me. So I quickly logged onto YouTube, and yeah, the koki frog is loud. Cokie Frog is loud.

You can almost feel the property prices dropping in California the longer you listen. And thinking about the Cokie Frog, I find it sort of funny that, of course, invasive animals are hitching a ride on invasive plants. What's the main organization in the U.S. that keeps an eye on this? Who are the nature police here? Well, so this is actually one of the challenges. So in general, it's going to be the state fish and wildlife agencies on the state level. At the federal level, it's the U.S. Fish and Wildlife Service. The problem is that when things are getting moved around via something like the nursery plant trade, it kind of falls in this gray area between, is this a problem that the U.S. Fish and Wildlife Service needs to tackle? Or is this a problem that the U.S. Department of

Agriculture needs to tackle? It's like when the LAPD and the FBI turn up on the same crime scene. Or it's also like here in LA, we have so many smaller cities. And so if something happens on one of the streets that's on the border between LA and another, the debate is like, okay, who has to deal with this problem, right? Of course, all departments on both the state and federal level are also hugely underfunded. They can target a few invasive species at a time, but not all of them. Begging the question, is it even worth the trouble? Is there an argument, look, it's just survival of the fittest. All these things are flying around. If a stronger lizard beats some native lizard, just that lizard wins and on we go.

I think what it comes down to is it comes down to sort of our value system. What do we want to experience in nature? Do we want 10 years from now, 20 years from now, whether it's us, whether it's subsequent generations, do we want them to experience endemic species and native species? Or are we okay with biotic homogenization where in every Mediterranean city around the world, you have the same suite of successful invasives? Are we okay with a future where we see that level of homogenization where we've lost a lot of native species because we haven't taken a proactive approach to trying to limit some of these non-natives showing up?

because we haven't taken a proactive approach to trying to limit some of these non-natives showing up. Stay tuned for more Flightless Bird. We'll be right back after a word from our sponsors. Flightless Bird is sponsored by BetterHelp. Now, one of the relationships I'm proudest of in my life is with one of my oldest friends, Hayden, who I met at journalism school in New Zealand. You know, it takes a lot to keep a friendship maintained. I mean, we do a thing once a year called Festivus, which is where we air our grievances in front of a group, but that's a whole other thing. The better way to maintain a relationship is with therapy.

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different states are finding creative ways to get it under control, to incentivize people to chop the tree down. Professor Teresa Cully, the plant biologist from earlier, told me about one of these plans. South Carolina did a really interesting thing with a buyback program, or someone has to bring evidence that they've cut down their tree, and then they'll get a new free tree. So there's things like that that people do.

It's complicated getting rid of America's invasive flora and fauna, be it an obnoxiously loud frog, or a tree that smells like the inside of a male sauna. And yes, I'm back on about this tree again, because the more you dig into the history of the Callery pear tree, the more you find out how much it's crapped into America's DNA in some really fascinating ways. And trust me, I did not expect the story about this particular tree to go where it's about to go. Just a few moments ago, something believed to be a plane crashed into the South Tower of the World Trade Center.

I just saw flames inside. You can see the smoke. So when the 9-11 terrorist attacks hit, of course, the towers came down and they were grappling with this horrible tragedy. But people started to notice next to where the towers collapsed, there was this tree. Most of the branches were torn off. You know, there were a few things left. There was a little bit of leaves, but it managed to survive this tragedy. And so people working there in the recovery efforts saw it as a symbol. And so they actually dug up the tree. It's a mature

tree. They had to dig it out of the ground. So they had to be cutting out some of the roots, removed it to a nursery and babied it essentially. The tree actually grew in this nursery and thrived, which is amazing in itself. And then they planted it back. So if you go to the 9-11 memorial today, there's what they call now the survivor tree. And look, just to clarify, what kind of tree is this? So the survivor tree is a calorie pear tree. And it shows you that one of the reasons people like the calorie pear is you can abuse it a lot. You could forget to water it.

You can mow its roots. You know, it still will come back. I go to the YouTube channel for the 9-11 memorial and find a video called The Survivor Tree. It's a really cutely animated video of the tree. And yeah, it's a calorie pear tree. It's narrated by, I guess, the tree. From the worst day of all to my comeback with glory, I'm the survivor tree. I was a strong pear tree at the World Trade Center. I was strong every spring. I was strong every winter. One day in September, when the buildings came down, it was the worst day of all. It's actually a really endearing video. Of course, there's no

talk of the smell, but you can't help but get caught up in the symbolism of a tree that survived that horrible day in America's history. And of course, it was a virile calorie pear tree. So what you see nowadays when you go to the 9-11 site, there's a survivor tree. It is starting to come apart a little bit. So it's all wired together. But people go and they visit the site and they go to see the tree among the other areas. And so what has also happened is there's a group of people where they wanted to, of course, use it as a symbol. And so they collected seeds from it and they had a local high school plant them all and they have seedlings. So there's a survivor tree seedling program. So

people from other areas of the world can actually get offspring of the survivor tree and plant their own survivor trees in other places around the world. This must be controversial in some ways because you've got states now banning this tree. I mean, what's New York's stance on this particular tree? Yeah, and that's a great question. So New York right now is looking at the tree, you know, and at the species itself for consideration of whether it should be banned or not. But it shows a really interesting crossing over of ecological threat versus symbolic necessity of the human spirit. So it's one of these examples of where those are actually clashing. My journey started with a simple sniff of the nose. The waft of a pungent calorie pear tree sent me on a journey into the heart of America's relationship to both plant and animal. What had

I learned? Well, like most things in America, it seems simple at first, but as I went on, it got more and more complicated. The story of this one tree is as complicated as America itself, exploring the conflict between ecological danger and societal and emotional importance. And I'd learned that the US Fish and Wildlife Service and the Department of Agriculture have quite the problem on their hands when it comes to invasive species. Each state fighting their own good fight against their own invasive species, sometimes plant, sometimes

animal. And I learned that while I care about the Callery pear tree, not everyone does. Some people, like Greg from the Natural History Museum, they don't give a shit. They've got annoying frogs to deal with. This episode does start with the Call calorie pear tree, this very smelly tree. Were you aware of this tree when I walked into your office and started quizzing you about invasive species? No, I don't care about this tree at all. Isn't that wild? That was incredible. I had no idea. It's bonkers on so many levels.

I feel conflicted that our desire for symbolism. And of course, this is a hard conversation to have. It's kind of nutty, right? Because it's really important to have symbols. Yeah, and memories and hope. Hope. Yeah, hopefulness. But it's just such bad luck that the one fucking tree.

Oh my God. That survived the terror bad luck that the one fucking tree. Oh, my God. That survived the terror attacks was a fucking jizz tree. Now we're propagating it. And even though there's laws that we're not supposed to do. So you've got states coming in saying this is an invasive species. It can breed. Now it's getting out of control. It's spreading.

It's putting toxins in the soil. New York, they've got high school students coming in and taking seeds. And a seed program, not only to seed it, I guess, more over New York and the United States, but the world. I know. So America's doing this thing again where it's sending out its jizz trees to the planet.

Well, Survivor Tree. Now it's a fucking Survivor Tree. Yeah. And if you fight back against the Survivor Tree, suddenly it becomes political yeah it's exactly that's exactly which is so crazy oh my god every you like can't help but make everything political yeah i've been to the memorial site i never saw the tree i wasn't looking for the tree but it's there so i assume some people listening will have seen this at all

it sounds like a horrible little tree they're having to hold it together wire it's like falling apart they're really trying to keep it alive it's in hospital it wants to die like let it go they can't because once they let it go it's the last remaining thing which i get it's the end of it all oh it's tough it's tough. High school is a through line in this whole episode. Maybe high school is always drawn back towards this tree. It's just a part of their life. It's a part of the high school experience in America. Where you discover cum.

Bradford Pants. Yeah, it's life. I mean, maybe we just need to get used to America having that smell. Well, it's more that it can't get so out of control. It's not just about the smell. Oh, it's everything else it it can't get so out of control it's not just about the smell oh it's everything else it's doing yeah it's taking over from like others from native plants and taking up a whole lot of space in the soil so that's the show i mean i love also that there's a buyback scheme it's like like guns like america can't get its head around the gun thing but like a tree

a buyback system like bringing a bit of branch of a calorie tree and get another nice tree. It's so true. That exists, but there's no gun reform. Oh, my God. This episode is making me embarrassed for America. It's deeply unusual. Yeah, deeply unusual. I do urge you to go to the 9-11 Memorial YouTube

there's a lot of calorie pair content there and the videos that are narrated from the perspective of a tree I mean it's cute but tonally it's a wild thing it is wild hearing a little tree talk about terrorism it's just difficult I'm sure there's a museum maybe there's magnets of the survivor tree I would love a little calorie

pear tree magnet that'd be a great christmas present okay i'll look into it this is really good i mean maybe new york will be the only place you can go to see this tree eventually you know other states will ban it maybe that's the one state that's going to have the tree as a symbol and that'll be the one state that smells like jizz. I wonder if over time with more cross-pollination, if the smell will get less. Yeah, that'll change. Exactly. Yeah, as it naturally goes out and breathes and does its thing.

I mean, that's the other very comical thing. I mean, you had the same question when I was paying you that doc that I had. What wants to pollinate? This is disgusting. Of course it's flies. Yes, exactly. It's like all the nastiest things are related to this yeah terrorism yeah like horror yeah it's nuts flies ew so yeah wow this was quite a journey i'm glad you went on

this journey with me i'm excited for the day that rob texts us saying i've just smelled the tree you'll be on the alert now your Your nostrils will be sniffing. Well, maybe you should just go to the 9-11 Memorial, go see the survivor tree and see what you smell. I'm going to hop on a plane after this. Yeah. It's the one flower you don't want as a perfume. I wonder how that one smells, the survivor tree.

I'm curious. Yeah. Also, maybe it's so old now it's not flowering. Exactly. It's just like too sick. Yeah. But I guarantee if that survivor tree has flowers It'll smell like jizz Or periods And hey that's okay as well

Not knocking jizz, not knocking periods All of it's natural Everything has a smell I feel like I smell pretty good today I think I'm okay Wow scary Well this was really fun I feel like I smell pretty good today. I think I'm okay. Yeah. Wow. Scary. Well, this was really fun.

I think we all became more American together. I do. We learned a lot. So much. I'm embarrassed. And I guess that's part of it. Watch out for those loud frogs. Watch out for weird lizards.

Watch out for calorie pairs. Just stay safe out there, you know? Bye. Bye. Bye.