Nearly all tequila is made from cloned plants that are vulnerable to species collapse. In Mexico, a small group of people is trying to change that – and protect an endangered, nectar-slurping, agave-pollinating bat that’s only three inches long.
EPISODE 5 TRANSCRIPT
Hey, this is Buzzkill. I’m Teresa Cotsirilos. There are an estimated 350,000 different pollinator species on this planet. And over the past few episodes, we’ve only really talked about one of them. Bees. Bees pollinate about 75 percent of the fruits, nuts, and vegetables grown in the U.S. And now that farmers have basically turned honeybees into livestock, about a third of the foods Americans eat are pollinated by honeybees specifically.
But pollination in our food system relies on a lot more than just honeybees.
News clip: The role of moths is increasingly being seen by scientists as absolutely crucial in terms of pollination.
Nature documentary clip: In the heart of this grove, half a billion monarch butterflies lie sleeping.
Nature documentary clip: Hummingbirds are driven by nectar. And their specialized bodies are purpose-built for harvesting sugary fuel from flowers.
Teresa: There’s an obnoxious little fly called the biting midge.
Kids’ show clip: Hi, I’m Madge, and people call me a flying midge.
Teresa: Some people call it the flying midge.
Kids’ show clip: You can hardly see me I’m so small.
Teresa: These midges have been the stars of nature docs. And goofy kids’ shows like this one.
Kids’ show clip: If it wasn’t for me, you couldn’t have any chocolate to eat.
Teresa: And that’s because they help provide chocolate. Do I even have to say that no chocolate would be a buzzkill? Cacao trees are tricky to pollinate. The flowers are only half an inch or so in diameter, about the size of your thumbnail. So tiny that many pollinators can’t access them. But biting midges are about the size of a pinhead. And it’s one of the cacao tree’s most important pollinators.
Chocolate is a multibillion-dollar global industry, and it primarily rests on this fly’s teeny-tiny shoulders. And chocolate isn’t the only food that relies on non-bee pollinators, at least to some extent. Globally, non-bee insect pollinators provide over a third of all visits to crop flowers.
Think about how much less food we’d have if they all disappeared.
Here’s a basic fact that lies at the heart of this series. Biodiverse ecosystems are more resilient. And when we kill off pollinator biodiversity through industrial agriculture, we weaken the crops we produce. In our last episode, we saw that sometimes, you only need a few committed people to protect a thriving and biodiverse ecosystem.
For this episode, Buzzkill reporter Elliott Woods takes us to the heart of tequila country, where the future of your favorite margarita is tied to the survival of migratory bats. From the Food & Environment Reporting Network, this is Buzzkill Episode 5, Bats and the Blue Agave.
Elliott: It’s a hot day in late July, and I’ve spent the last four hours hiking up to a cave in Big Bend National Park in Texas, close to where the Rio Grande divides the United States from Mexico. The entrance to the cave is about 7,000 feet above sea level. And it’s a big, yawning hole in a sheer rock face. The air is cool and damp.
There’s water dripping from a crack in the rock, and the smell of bat poop is overpowering. I can hear squeaks and wingbeats deeper inside the cave, where hundreds of bats are hanging from the ceiling. It’s not my idea of cozy, but for the bats, it’s the Four Seasons. This cave is one of the only known maternity roosts of endangered Mexican long-nosed bats.
A gray-brown, nectar-eating bat that’s about 3 to 4 inches long. They’re really tiny. And they may just save the tequila industry someday. You probably don’t think of bats when you think of tequila, but that spirit comes from a plant called agave tequilana, also known as blue agave. Over the last century, industrial monoculture practices have caused a catastrophic loss of genetic diversity on Mexico’s blue agave plantations.
That makes them vulnerable to disease, and puts them and the global tequila industry they supply, at risk of collapse. And that’s where the bats come in. Scientists believe that bats can help restore lost biodiversity to agave plantations, simply by doing their ancient job of spreading agave pollen far and wide.
Agave pollination is a job that long-haul-flying, nectar-slurping bats like the ones in this cave do best. But the bats are in trouble, too. They’ve been on the U.S. endangered species list since 1988 due to the loss of roosting caves to vandalism and home construction, the encroachment of agriculture into wild ecosystems, and climate change.
In Mexico and the United States, conservationists, small farmers, and tequila producers are working against industry norms to boost the bats’ food supply so that these tiny, vulnerable creatures can have a shot at recovery and maybe help save the tequila industry, too.
I’m walking between neat rows of blue agaves that stretch up and over the horizon. It’s a stormy day in El Arenal, Jalisco, in the tequila valley northwest of Guadalajara. And the blue agaves look like humongous pineapples. When you make tequila, you harvest the heart of the blue agave plant. Then you roast it to release a sugary liquid that’s distilled into alcohol.
The agave’s waxy blue spines have serrated edges, and they’re almost as tall as my shoulders. And as I learn the hard way, their natural defenses are sharp.
Elliott: My first stab. I just got stabbed in the chest by an agave spine.
Rodrigo Medellín: Welcome to the agave country.
Elliott: My first bite.
That’s Rodrigo Medellin, an ecologist who’s also known as the Bat Man of Mexico.
Rodrigo’s a legend in the world of endangered species conservation. And he’s also a bit of an interspecies sex therapist.
Rodrigo: What you see here is that the agave flowers are almost finished now.
Elliott: Rodrigo’s been helping blue agaves mate with the aid of their most loyal pollinators, long-nosed bats. The agaves are dependent on bats for sexual reproduction. But on blue agave plantations, that relationship has been almost completely severed by the long-standing practice of cloning. Instead of planting seeds from pollinated plants, growers plant hijuelos, basically sprouts that grow from an agave’s underground stems and are genetically identical to the mother plant.
We’re in a field of clones right now that belongs to Rodrigo’s friend, a biologist and small agave cultivator named Leobardo Padilla, or Leo for short.
Leo: This field was planted in 2018, May of 2018. Six years and two months.
Elliott: Rodrigo and Leo brought me here to show me something really important that you rarely see on a blue agave plantation.
Rodrigo: It’s a flowering stalk. It’s a beautiful, massive, massive column growing from the center of the plant.
Elliott: Flower stalks like this one are essential for sexual reproduction.
Leo: The quiotes, well, they have only, hmm, since March that the agaves started to bloom now.
Elliott: Known as a quiote in Spanish, the flower stalk looks like a 10-foot-tall piece of asparagus with a half dozen dinner plate-sized disks of yellow flowers sticking out from branches near the top.
Rodrigo: Agaves grow and grow, and they accumulate sugar and accumulate sugar year after year after year until sexual maturity comes to them. And then when sexual maturity comes, every last ounce of those agaves is invested in this amazing, massive flowering stalk.
Elliott: Those gigantic flowers contain capsules of nectar that open at night to lure in bats. Their furry little faces and bodies get covered from head to toe in pollen, which they carry to the next flowering plant.
Growing the flower stalk takes every last bit of the agave’s stored-up energy.
Rodrigo: They’re going to die right after this. You grow for six to eight years, and then you’re going to have sex once and die. That’s it. That’s the story.
Elliott: But it’s not the whole story. Agave growers almost never let flower stalks grow.
Rodrigo: If we harvest the plant before the flowering stalk starts growing, then you maximize the amount of sugar that the agave has and therefore you maximize the amount of alcohol that you produce from it.
Elliott: For producers, more alcohol means more profit. But since the plants never flower, the bats never have a chance to pollinate them. No pollination means no seeds, which is why growers have been relying on clones grown from rhizomes. And that’s a major problem. After so many generations of cloning, the gene pool has gotten so small that nearly all the blue agaves in Jalisco are copies of just a handful of mother plants, which puts them at severe risk of infestation.
Rodrigo: And since your plants are very close siblings, brothers, sisters from each other, twins from each other, because they share 99.9 percent of their genome with each other, then that is the perfect recipe for these pests and the diseases to affect your entire field.
Elliott: The most pernicious pest is known in tequila country as a picudo, in English, a weevil.
Rodrigo: The weevil is a black bug, the size of maybe your fingernail, maybe a little bigger, um, that has a long tubelike mouthpiece. That is used to go and dig into the core of the agave, and then they lay the eggs in that hole. And then the larvae start feeding on the inside of the agave core. The problem is not necessarily the weevil itself, but the weevil is the vector of a fungus and a bacteria that has been killing agaves for 10 years and more.
Elliott: The near total lack of biodiversity in blue agave plantations also means the plants lack the capacity for adaptation.
Rodrigo: One plant is affected by the disease, all the plants are going to be sick. So there’s like 40 percent of the agave fields that have been already affected by the disease, and this is growing.
Elliott: According to Rodrigo, the monoculture plantations in tequila country could be one plague away from annihilation. And this is not some abstract threat. It’s already happened more than once.
Between 1993 and 1999, a pest infestation wiped out an estimated 25 percent of the agaves in Jalisco. Dozens of distilleries were forced to close down, and the industry fell into a yearslong slump. The cycle repeated again in 2010, when a fungal infection killed off an estimated 35 percent of blue agaves in Mexico.
These plagues are bad news for companies like Jose Cuervo and Sauza, and they’re even worse for thousands of people whose livelihoods depend on the industry, from small planters, to the laborers who work the agave fields, to production and distillery workers.
Worse still, each plague has provoked agave growers to deploy larger and larger arsenals of chemicals to protect their clones, which scientists say may actually increase the likelihood of future plagues, and which turns agave cultivation into a truly industrial and intensive monoculture.
Rodrigo: Now monoculture is an invitation for diseases or for predators or for whatever, uh, best insect to come and have a feast because you have thousands of plants that are defenseless there and they are next to each other. That is what does away with biodiversity.
Elliott: And so how does that relate to the requirement to apply, uh, megatons of atomic loads of chemicals and, and other artificial substances?
Rodrigo: The only way to control that pest is putting agrochemicals, putting pesticides, massive amounts of pesticides to kill every last one of those bugs.
Elliott: But massive application of chemicals kicks off an arms race that the bugs will eventually win.
Rodrigo: The populations of the bugs are so big that they are also evolving and adapting to all of these chemicals, generation after generation after generation. So we’re making superbugs in the process, and therefore we have to apply super chemicals that are more and more toxic every time.
Elliott: Rodrigo and Leo have a better idea: more pollination, which means more bats.
Rodrigo: The flowers of agave open at night, number one. And number two, the pollen becomes alive, like at 9 p.m. That pollen is going to live for the next 12 hours. So it doesn’t matter if a hummingbird or a bee comes here at 8 a.m. They will be moving pollen, but the pollen that they’re moving is dead.
Elliott: Okay.
Rodrigo: That’s why it’s only the bats that are moving the living pollen at night …
Elliott: When they swoop in to feed, bats not only get a belly full of supersweet nectar, but they also deliver pollen from wild plants that could be dozens of miles away, which may help generate seeds with genetic resistance to pests and plagues.
Rodrigo: Bats have domesticated agaves into producing a lot of nectar. That is what the bats want. But agaves have enslaved bats, so that bats have to come back and come back and come back and come back to the flower to get as much nectar as they can.
Elliott: The idea is simple. Instead of poisoning the air and soil in an attempt to fend off armies of superbugs, working against nature and destroying biodiversity on the road to mutually assured destruction, why not work with nature?
Rodrigo: These things have been coexisting with, with bats for more than 10 million years, and they have connected their natural history very, very tightly knit.
Elliott: Why not help long-nosed bats play their ancient role of matchmaker between far-flung agaves?
We say goodbye to the flower stalk and pile into Leo’s truck just as a summer thunderstorm lets loose.
On the drive back to Arenal, Leo tells me that some of his fellow agave planters think he’s nuts to waste perfectly good agaves.
Leo: They’ve grown up with a conventional monoculture plantation, and they’ve told me, you’re stupid.
Elliott: But Leo has a big presence on social media, and he says some of the younger growers are more open to the idea.
Leo: But now, I put out my publications, and they’re watching. And they’re like, ah, what are you doing?
Elliott: The younger growers aren’t so stuck in their ways. Leo says they understand the value of sustainable agriculture, and they also see the marketing advantage of eco-friendly products.
Leo: They’re now seeing change is coming. Changing how to sell more easily. So, you’re going to have to bring them along from that side.
Elliott: For now, the movement’s still small. But Rodrigo and Leo are determined to help it grow. The flower stalks bristling up from Leo’s field are more than they seem. They’re flags in a movement to save bats and agaves, and in the process, to protect farmers and laborers in the towns that have grown up around the industry.
But Leo’s only a small grower, and if the idea is going to spread throughout tequila country, big tequila producers will have to get on board. Rodrigo’s working on it.
The next morning, Rodrigo and I drive to a town in the Jalisco Highlands called Arandas. The plan is to meet up with a tequila producer who has some very special blue agaves to show us.
Rodrigo: What we’re going to see is the first generation of six-year-old agaves. These agaves, different from the gazillion other blue agaves that we’ve been seeing all over, these are the result of seeds sprouting. And those seeds came from the bats pollinating the flower of agaves and waking up genes that have been dormant for more than a hundred years.
Elliott: The seed-born agaves were grown as part of Rodrigo’s Bat Friendly project, which requires tequila producers to let a certain number of their plants live out their natural lifecycle.
In other words, to grow flower stalks, get pollinated, and die.
Rodrigo: If you let 5 percent of agaves in one hectare, you are feeding 100 bats in one hectare. That is a hell of a lot of bats.
Elliott: The project launched in 2016. It’s still in its infancy, but Rodrigo has big dreams.
Rodrigo: So when you multiply that by the thousands and thousands of hectares of agave tequilana, if and when the industry adopts this as the standard, we’re going to be feeding millions of bats in all of this area.
Elliott: And along with feeding bats, those pollinated agaves would produce seeds that could unleash a revival of genetic diversity.
On the two-hour drive to Arandas, we pass endless fields of clones.
Rodrigo: Those in the back were five- and six-year-olds. This is four-year-olds.
Elliott: How can you tell how old they are?
Rodrigo: This species is harvested at age seven or eight, uh, depending on, on the size of the, of the core.
Elliott: Signs for herbicides and fertilizers are posted at the edges of the fields.
Here’s a sign for Mustang Max Insecticida. That’s probably the third or fourth sign I’ve seen for insecticides or herbicides or …
Rodrigo: Oh yes, lots of, lots of agrochemicals here. Every one of these fields is pumped full of pesticides and fertilizers and weed killers and so on and so forth.
Elliott: The application of massive amounts of chemicals to fertilize depleted soil and protect clones from pests has polluted tequila country and set the industry up for a potential collapse. But one thing Rodrigo says the industry is not responsible for is driving the Mexican long-nosed bats toward extinction.
Rodrigo: Some people have said that the tequila industry is partly, uh, guilty for putting these bats in danger of extinction. And that is not true. That is not true.
Elliott: Rodrigo helped get the bats onto the U.S. endangered species list in 1988. And he says the destruction of critical roosting sites has been the heaviest blow to the bats, not a lack of food.
Rodrigo: The bats are going to find food no matter what because of their incredible flying powers. The diet of these bats is very diverse. More than a hundred species of plants, from columnar cacti to tropical trees to all kinds of different plants.
Elliott: We finally arrive at a tequila distillery called Los Alambiques. It belongs to Carlos Camarena, one. of three tequileros who’ve signed on to Rodrigo’s Bat Friendly project. When we stop at the gate to check in with the guard, the aroma of roasting agave fills the car.
Rodrigo: This is, this is, oh, you can smell the beautiful fermentation of agave juices that are in there.
Elliott: Smells like molasses.
Rodrigo: It opened, it opened not a year ago …
Elliott: Carlos meets us outside.
Cross talk in Spanish: It’s always a pleasure. Hello. Hello. Good afternoon. My name is Elliott. Elliott.
Elliott: He’s a slender man in his 60s with a thin mustache. He’s wearing jeans, a plaid button-down shirt, and plain leather shoes. You’d never guess that he’s a tequila tycoon.
Carlos is a master distiller and a fifth-generation tequilero whose brands include El Tesoro, Tapatío, and Tequila Ocho. He’s small compared to giants like Jose Cuervo and Patrón, but his tequilas are top-shelf.
We hop in his red Toyota pickup and head out to the fields where Carlos is growing the bat-friendly agaves Rodrigo told me about.
And where are we pulling up to now, Carlos?
Carlos Camarena: This is my personal property. It’s called Rancho El Nacimiento. As I was mentioning, this is the ranch where we have the, the vast majority of our agaves in, I would say, in my sanctuary, in the place where I come to relax every time that I get stressed.
Elliott: But these peaceful fields are under threat.
Carlos: Because we have one major concern regarding the health state of our agaves. And that concern, it is one little bug that is called, in Spanish, picudo, because it has a beak.This little animal, it is a disease transmitter.
Elliott: The picudos, or weevils, thrive in neglected fields.
Carlos: There’s nobody taking care of it, and therefore they become, I would say, very easy prey for those bugs to be there, because nobody is trying to get rid of them somehow.
Elliott: During boom times in the tequila industry, there’s a mad rush to plant agaves on every available patch of ground. And when that results in a glut, prices collapse, and lots of the get-rich-quick growers abandon their crops.
And that’s when the pest populations explode.
Carlos: And from there, they are attacking all of the neighboring fields, and that is a …
Elliott: As it happens, the industry is in the midst of a glut right now. Prices for agave have fallen from a record high of almost two U.S. dollars a kilo in November 2022 to about 50 cents a kilo at the beginning of 2024.
And according to Carlos, the cycle of abandonment is starting all over again.
Carlos: Clones, they all have exactly the same genetic information, but if we get a, a serious disease, it could wipe out the blue agaves in the country, and therefore it could wipe out the whole tequila industry. So …
Elliott: That industry was worth more than $16 billion globally in 2023 and employed tens of thousands of people in Mexico.
For Carlos, just like with Leo, growing bat-friendly agaves cuts into the bottom line, but he says the potential long-term benefits for his family’s company and for the industry are worth it.
Carlos: We are providing food for them, and what we want in exchange from the bats, it is to bring pollen from other agave species in order to have a cross-pollination that could eventually also lead us to have a genetic difference …
Elliott: We park near a stone fence flanked by huge trees. Carlos jumps out and leads us over to a row of agaves, where some of the seed-born plants are mixed in with the clones.
Carlos: You see the plants, you will say, well, this is not a blue agave. It doesn’t even look like a blue agave. I can tell you it was born from a blue agave seed. So to me, it is a blue agave. So you can witness what a crazy project we have in our hands.
Elliott: Let’s, uh, let’s do it.
There’s a blue agave right here. And then there’s another one, three plants down, that looks way different. Tell me how it looks different.
Carlos: The base, it is thicker. The leaves are thicker than the blue agave. The blue agave has kind of thin leaves. And these, you see, they are completely thick. The spikes are completely different. So it is, it is like looking at an individual from a completely different species. But it is born from a seed of blue agave. And this is just one example, because they went in all completely different directions. There are some plants that are taller, shorter, fatter, skinnier. And to me it is exciting, because hey, we are getting into something …
Elliott: The Bat Friendly project is part of Carlos’ plan to hand a healthy company over to his daughters.
Carlos: When we started with this project, I thought that I would never see any result in my lifetime. I thought that maybe my kids or my grandkids would see something 80 years from now, 10 generations, 8 years, 80 years. But the surprising part is to see, even with the first generation, how visually you start looking that there’s some difference. So the hope is that among those changes, eventually, we may have some plants that are resistant to the attack of a common disease that will come to affect the agave tomorrow or in 100 years from now. And out of those survivors, we can keep on doing what we do. Keep on growing agaves and produce tequila.
Elliott: Back at the distillery, Carlos leads us up onto a catwalk between rows of cylindrical steel tanks, where I get to sample the latest batch of tequila.
Cross talk in Spanish: Salud. Salud.
Elliott: Tequila fresh out of the still.
Carlos: At 110.2 proof.
Elliott: What do you smell, Carlos?
Carlos: I smell some cooked agave. I’m smelling some minerality. I smell some herbaceous, but to me this is sweet. I’m smelling a lot of the cooked agave coming out of the oven.
Elliott: Your family has been doing this for well over a century. You know everybody in the business at this point. Do you think the Bat Friendly program can grow to a bigger scale? What are your hopes for the future of Bat Friendly?
Carlos: Yeah, I mean, what I can see regarding my daughters, they are very interested, and I’m sure that they will continue with this. So the next generation is getting involved with this. But I hope that there will be more people involved, the more they know about it.
Elliott: It’s raining and almost dusk when we say goodbye to Carlos outside the distillery.
On the drive back to Guadalajara, Rodrigo explains how Carlos’ seed-born agaves, which are the offspring of mothers that were pollinated by bats, are proof that the Bat Friendly program is already working.
Rodrigo: Waking up genes that have been dormant for more than a hundred years, you don’t know what to expect. But you are absolutely certain that the diversity is going to incorporate some really interesting and hopeful and helpful, uh, characteristics into the agave.
Elliott: Not only did the flower stalks in Carlos’ fields turn a historic food desert into an all-night diner for bats, but the seeds that resulted from all that pollination grew up to express an astonishing variety of new traits.
Rodrigo: That is what’s giving me hope. There’s a lot of all of these genes that have been dormant, that the bats can help us rescue and re-express in the future little agave plants. That is the nature, the gist, the substance …
Elliott: Rodrigo doesn’t imagine a future in which all blue agaves are grown from the seeds of bat-pollinated plants. But introducing new genetic material to even a small fraction of the plantation agaves could lead to important adaptations.
Rodrigo: That is the nature, the gist, the substance of the Bat Friendly program. Rescuing those dormant genes and selecting the best ones for survival, for …
Elliott: As for the bats, Rodrigo hopes the program will one day transform tequila plantations from dead zones into major feeding areas for Mexican long-nosed bats and other nectarivorous bats.
Rodrigo: I do dream of a future in which the common practice for production of tequila is bat-friendly. That I dream. That is something that I can see even in my lifetime to happen.
This episode was reported by Elliott Woods and produced by Buzzkill’s senior producer, Alyssa Jeong Perry. Special thanks to Dr. Loren Ammerman at Angelo State University and Gustavo Martinez. Buzzkill is a production of the Food & Environment Reporting Network and is distributed by PRX. Adizah Eghan, Theodore Ross, Brent Cunningham, and Tom Laskawy are Buzzkill’s executive producers.
The music arrangement and audio engineering were done by Sound Sanctuary. Our theme song is by Sandra Lawson Ndu. Naomi Barr is our fact-checker. Funding for this podcast is provided in part by the BAND Foundation, and I’m your host, Teresa Cotsirilos.
Thanks for listening.