1. Podcasts
  2. TED Talks Daily
  3. The magical, mesmerizing migration of monarch butterflies
TED Talks Daily

26 Mar 2026 · 13m · 7 chapters

Episode artwork

The magical, mesmerizing migration of monarch butterflies | Jaime Rojo (re-release)

In short

Monarch butterfly migration and decline, what scientists still don’t know about how they navigate, and how people can help protect them.

Guest backgrounds

Photographer Jaime Rojo (TED 2024) documents monarchs in remote mountain habitats in Mexico; he also discusses research by scientists including Christine Merlin (solar compass via antennae), University of Iowa (radio tracking), and University of Michigan (ultralight long-distance tracking sensors).

Key claims

Monarchs are an ecological health indicator and have declined for ~40 years. The migration takes 3–5 generations; a “supergeneration” can live up to ~9 months and travels ~3,000 miles to only 12 isolated mountaintops in central Mexico. Navigation remains mysterious. Major threats include loss of prairie and milkweed, herbicides/GM crops, roadkill, light pollution, deforestation, and climate extremes.

Notable examples

tagging stickers used by volunteers (2+ million butterflies over 30 years); prairie strips in Iowa where Rojo photographed mating monarchs; Mazahua Day of the Dead (Nov 1) where monarchs symbolize ancestors; drones used to find milkweed; monarch clusters forming in Mexico reserves and Rojo capturing “20,000 frames” for a sky-filled shot.

Written by AI. May contain mistakes.

Chapters

0:45

The Journey of Monarchs

Exploration of the annual migration of monarch butterflies and their ecological significance.

“That was photographer Jaime Rojo from his 2024 talk, which we are resharing today in honor of the monarchs on their journey.”
4:48

The Monarch's Migration Mystery

Details on the extraordinary journey of monarch butterflies and their navigation challenges.

“Few insects have captured our imagination like the monarch butterfly.”
6:00

Challenges Facing Monarchs

An overview of the various threats that monarchs encounter during their migration.

“and they undergo a hormonal change in their bodies called the diapause.”
8:10

Conservation Efforts for Monarchs

Discussion on grassroots efforts to restore habitats and protect monarchs.

“We use these stickers that are very light, and they contain coded information and information about their origin.”
10:20

Cultural Significance of Monarchs

Exploration of how monarchs are viewed in Mexican culture and their symbolic importance.

“There's many people trying to protect them.”
12:20

The Beauty of Monarchs and Their Future

Reflection on the beauty of monarchs and the hope they represent for ecological health.

“I have spent the last 10 days doing the same thing in the mornings.”
14:00

The Majesty of Monarch Butterflies

Discover the significance of monarch butterflies in North America and their role in inspiring hope.

“You can see the sky is covered in butterflies.”
A man walking through an airport, asking his phone a question

Ask about this episode

Get the gist, explore an idea or ask about something said.

Claude

On TED Talks Daily, what are the key points of this episode?

Searching your listening

Transcript

Automatic transcript. May contain errors.

0:03You're listening to TED Talks Daily, where we bring you new ideas to spark your curiosity every day. I'm your host, Elise Hume. Every year around this time, something really special happens. Millions of monarch butterflies migrate over thousands of miles north to breed and return to the warmth in the Northern Hemisphere. And when they travel, they produce one of the most iconic wildlife spectacles in the world, all while providing us with an important indicator of ecological health. I know for sure that if there is one iconic species in North America, this is the monarch. We are living in very polarized times, and the story of the monarchs can inspire hope again, can bring unity across our borders.

0:49We need that. That was photographer Jaime Rojo from his 2024 talk, which we are resharing today in honor of the monarchs on their journey. He shares his experience photographing these mesmerizing insects deep in their remote mountain habitats in Mexico, dives into the latest research into the mysteries of this migration, and shares how each of us can join the growing movement to protect them. So I have to ask you that don't let this beautiful illusion of plenty fool you, because the monarchs are in serious trouble. But there's also good news. There's many people trying to protect them. That's coming up right after a short break.

1:53at the cost of your privacy. That's why DuckDuckGo built Duck.AI so you can chat privately with the same AIs you might already be using, like ChatGPT or Claude, and protect your data from hackers, scammers, and data-hungry companies. There's no account required. It's completely free. Plus, it's from DuckDuckGo, known for protecting your data, not collecting it. So you can chat freely without worrying about your AI conversations getting stored or exploited. If you want to use AI without giving up your privacy, visit duck.ai slash talk today. That's duck.ai slash talk, a private way to chat with AI from DuckDuckGo, where AI is always optional and private.

2:33This podcast is supported in part by Bill, the intelligent finance platform that helps businesses and accounting firms scale with proven results. We often talk about the habits and systems that help people do their best work. For many leaders, that might include building processes that reduce friction and create clarity. That is exactly why so many finance leaders turn to Bill. With AI-powered automation, Bill isn't just moving money. They're simplifying financial operations for nearly half a million customers. They're even trusted by over 90 of the top 100 U.S. accounting firms to get it right.

3:05That trust is built on scale. Bill has securely processed over a trillion dollars in real transactions, supporting teams and handling payables, receivables, and expenses. When financial tasks are organized and visible, it can free up time and energy to focus on what matters most, whether that's your team, your mission, or your community. Visit bill.com slash proven and get a$250 gift card as a thank you after speaking with a bill expert. That's bill.com slash proven. Terms and conditions apply. See offer page for details. This episode is brought to you by Bombas. Lately, I've been thinking about the small things that make a big difference in my day.

3:43You know, those upgrades you don't realize you needed until you try them? That's exactly what happened with Bombas. I picked up their women's Pima cotton v-neck tee, which is what I own, and now I reach for it constantly. Whether I'm recording or just doing school pickup, it works. Dress it up with a blazer, keep it casual with jeans. It's that rare piece that adapts to whatever your day throws at you. And their base layers? Just game-changing. The underwear and tees are so soft and breathable, you'll wonder why you settled for anything less. Here's the best part. Every purchase means an essential clothing item goes to someone experiencing housing insecurity.

4:23One purchase equals one donated. They've already given over 150 million items. Ready to upgrade your basics? Head over to Bombas.com slash TTD and use code TTD for 20 % off your first purchase. That's B-O-M-B-A-S dot com slash T-T-D, code T-T-D at checkout.

4:48And now, our TED Talk of the day. Few insects have captured our imagination like the monarch butterfly. Their migration is one of the most iconic wildlife spectacles in North America, but they are also one of the best environmental indicators we have of the health of our ecosystems. and they have been in decline for the last 40 years. So they might be telling us a bigger story, a story about our relationship with the natural world. Every year, these amazing insects undertake one of the most extraordinary journeys on this planet. It takes from three to five generations of monarchs to complete the whole migration.

5:31And it starts in Mexico in the spring, when the monarchs that spent the winter there traveled back north to lay their eggs. So the first and second generation of monarchs are born and remain in the USA, and they live up to six weeks, more or less. But most migratory monarchs belong to the third and fourth generation. And they emerge in the late summer, early fall, when the days start to get shorter, and it's cooler, and they feel it, and they undergo a hormonal change in their bodies called the diapause. And this puts their mating instinct on hold. And they live longer then. This supergeneration will live up to nine months, and they will complete the trip to Mexico, 3 ,000 miles, to a place where they have never been before.

6:23Because remember, they are the great-granddaughters of the butterflies that left in the spring. How they do it, how they find the exact same location remains a mystery. Especially if we consider that the sanctuaries, the forests they are looking for, are located only on 12 isolated mountaintops in central Mexico. And these are the perfect conditions for the monarchs. It is cool and moist in high elevations. But for years, scientists have been trying to answer the same question. How do they exactly find their way? There are many hypotheses. Some say it has to do with geomagnetism. There are evidences that they use visual cues from the landscape, you know, the ridges of the mountains.

7:06There's even theories about the odor of the pheromones of previous butterflies that were there the year before. But the truth is that we don't know exactly, and they are continually actively researching this topic. Physiologist Christine Merlin discovered that the monarchs used their antenna as part of a very sophisticated solar compass. And researchers from the University of Iowa are using this radio tracker to monitor the short-range movement of the monarchs when they feed. But this thing, as you can imagine, is very cumbersome. You cannot track the long-distance migration of a monarch with this.

7:44Until recently. A team from the University of Michigan is developing what promises to be a breakthrough technology. An ultralight sensor that, combined with an algorithm, will, for the first time, be able to track the single path of one monarch when they make it to Mexico, which is very exciting. But often, for these complex problems, the best and most efficient solutions are the simplest ones. We have been tagging monarchs for 30 years. We use these stickers that are very light, and they contain coded information and information about their origin. And this is how we discover where the monarchs were spending the winter in the 70s.

8:25And today, it continues to be one of the most popular environmental educations in North America, with volunteers having tagged more than two million butterflies in 30 years. Now, all these challenges that we face to track the monarchs are nothing if we compare them to what the monarchs themselves have to face throughout their long journey. especially starting in the prairies of North America, or at least what is left of them, because every year we are losing one million acres of prairie, being transformed into land developments and agricultural fields. And in the 90s, this problem got worse, because the widespread use of herbicides, combined with genetically modified crops, created a new problem.

9:12They basically wiped out the native grasses from the fields, including the milkweed. And the milkweed is the host plant of the monarchs. That means they needed to lay their eggs and to feed their hungry caterpillars. Without milkweed, the monarch population started to collapse. Now, our monarchs will continue their journey south, and they will have to face new threats, like roadkill that kills 3 percent of monarchs every year, or even light pollution from big cities that confuses them. It alters their patterns of sleep. But they will endure and eventually will reach Mexico. Aha, a last surprise, deforestation.

9:54Deforestation makes them more vulnerable to climate change. And as many of you know, climate change has many faces. Droughts, heatwaves or even snowstorms have become the major challenge for the monarchs in the short term. So I have to ask you that don't let this beautiful illusion of plenty fool you because the monarchs are in serious trouble. But there's also good news. There's many people trying to protect them. Working with the local communities in Mexico has been essential to control the deforestation rates. Farmers are working with conservationists, and they are using drones to analyze vast tracts of fields in search of milkweed.

10:39Because the science is very clear. All the monarchs need is their habitat back, And we can do that by planting milweeds and by planting native grasses with flowers. That's why thousands of citizens along the migratory route are turning their backyards into habitat for the monarchs.

11:03Even small parks in big cities like Chicago can't help, because these are like gas stations, pit stops for the monarchs when they travel. And as you can imagine, farmers play an essential part. These strips are called prairie strips and strategically located into areas of the field to attract pollinators. But they also protect the soil and conserve the water, so they benefit the farming. And all I can say is they work, because the only pair of mating monarchs that I was able to photograph during this story was during a visit to one of these prairie strips in Iowa. It will be the offsprings of these butterflies that in subsequent generations will complete the cycle and make it back to Mexico.

11:49And here they will be receiving high honors. For the Mazahua people in Mexico, the monarchs are the souls of their ancestors. And the Day of the Dead in November the 1st honors this tradition. And monarchs have become the undisputed pop icon of this celebration. Now, our monarchs now continue their life cycle in an alien world. Everything is different for them. They have never been here. They are tired. They huddle together. So the first days of the season, they are really vulnerable. I have spent the last 10 days doing the same thing in the mornings. I'm getting so close to the branches I want.

12:36I see that video. I think I have it for the first time in many days. By many days, I mean 20 days, but I did get the shots that I needed. Thank you. Now, as new waves of Monarch make it to Mexico, the branches soon fill up with clusters, and it is now when Dr. Green and his team will travel to Mexico and they will try to locate a signal from that sensor they installed earlier. They need just one, one signal that can answer some of the questions that we have about the migration. There is an increase in the temperature as the season advance and the monarchs start to get more active. They start to hang out in the local pub, which is the stream that runs down the hill, and with that increase of activity, there's also an increase in the tourism.

13:34And the tourism is the economic engine for this region during the winter months. And they all want to see this beautiful scene. The monarchs flying over the blue skies, an amazing sight. Sometimes it never happens. And sometimes it's okay. But one day, one day I got to witness something really extraordinary. I have been to this reserve so many times, and I have never seen something like what we have encountered today. It's just amazing. You can see the sky is covered in butterflies.

14:15All I want to do is to photograph. And I see your faces, I know what you're thinking, that this was the easiest picture of my assignment. It took me 20 ,000 frames to get this thing right, so it was not easy at all. So after all this time, I know for sure that if there is one iconic species in North America, this is the monarch. We are living in very polarized times, and the story of the monarchs can inspire hope again, can bring unity across our borders. We need that. And most importantly, it can reconnect us again with the natural world. North America will be a much sadder place. This planet will be a much sadder place if we lose the monarch.

15:03There is a growing movement to protect them, but we need to act now. So, muchísimas gracias.

15:17That was Jaime Rojo speaking at TED 2024. This talk was originally published in October of that year. If you're curious about TED's curation, find out more at ted.com slash curation guidelines. And that's it for today. TED Talks Daily is part of the TED Audio Collective. This talk was fact-checked by the TED Research Team and produced and edited by our team, Martha Estefanos, Oliver Friedman, Brian Green, Lucy Little, and Tonsika Sungmarnivong. This episode was mixed by Christopher Faze-Bogan. Additional support from Emma Taubner and Daniela Balarezo. I'm Elise Hu. I'll be back tomorrow with a fresh idea for your feed.

15:55Thanks for listening.

16:09This episode is brought to you by Bondwell Bistro Bowls. We often explore how to optimize our brains and our collective future, but we often neglect the very fuel that gets us through the hour. According to Bondwell's research, most people spend less than 25 minutes on their entire lunch, including the stress of actually deciding what to eat. And for the desk workers among us, over half rarely take a break at all, eating right over our keyboards. We want healthy options and high protein with zero prep, but finding that intersection can feel like its own full-time job. That's where Bondwell Bistro Bowls come in.

16:45They are these chef-crafted, plant-rich salad bowls designed to be a desk-friendly lunch that actually tastes like a real break. They're packed with fresh ingredients, craveable dressings, and crucially for those of us on the go, they're ready to eat with a fork included. It's a flexible, delicious way to fuel your momentum no matter what the day's big idea happens to be. Find Bondwell Bistro Bowls at your local retailer and learn more at bistrobowls.us. Eat well, be well, bond well.

17:44Terms apply. See CapitalOne.com slash bank. Capital One N.A. Member FDIC.

18:13Jaime Rojo: stressful and it's giving efficient and make money easily with no selling fees on depop. No seller fees means what you earn is yours. Your personal taste has value. Someone is literally looking for what you're not wearing. Download the depop app and list your first item today.

From the publisher

When monarch butterflies migrate, they produce one of the most iconic wildlife spectacles in the world — and provide us with an important indicator of ecological health, says photographer Jaime Rojo. Telling a story about our relationship to the natural world, he shares his experience photographing these mesmerizing insects deep in their remote mountain habitats in Mexico, diving into the latest research into the mysteries of their multi-thousand-mile journey and sharing how each of us can join the growing movement to protect them.


This episode originally aired on October 2024.

Learn more about our flagship conference happening this April at attend.ted.com/podcast

Hosted on Acast. See acast.com/privacy for more information.

More from TED Talks Daily

All episodes