Science Friday - The Best Tail For Balance | Bindi Irwin Wants Kids To Become ‘Wildlife Warriors’

Episode Date: February 27, 2025

The bone and joint structures in mammal tails help them keep their balance. Could those benefits be adapted for robots? And, in her first children’s book, conservationist Bindi Irwin takes little readers on a journey through Australia Zoo.In Search Of The Best Tail For BalanceIf you have met a cat, you’ve probably at some point been amazed by how acrobatic they are. They’re able to reorient themselves effortlessly, even in midair. It turns out that a lot of that twistiness comes down to having a top-tier tail. While most reptile tails can swing only in one plane of movement, mammal tails have more joints, leading to better inertial control. That lets mammals tweak their balance better, much as holding a balance pole can help an acrobat navigate a tightrope.In a recent study published in the Journal of the Royal Society Interface, researchers explored the biomechanics of different tails, and considered how a better tail could help build a better robot. Dr. Talia Moore, a roboticist at the University of Michigan, and Dr. Ceri Weber, a cellular and developmental biology postdoc at UC San Diego, join Host Flora Lichtman to talk tails.Bindi Irwin Encourages Kids To Become ‘Wildlife Warriors’Almost 30 years ago, conservationists Terri Irwin and the late Steve Irwin captured the world’s attention with their show “The Crocodile Hunter.” It introduced millions of people to Australia Zoo and the strange, often scary, sometimes cute, critters from Down Under.Now, Terri and her children—Bindi and Robert—are at the helm of the zoo, which is the setting for Bindi’s new children’s book, You Are a Wildlife Warrior!: Saving Animals & the Planet. In it, Bindi takes little readers and her own daughter, Grace, on an adventure through the zoo.Host Flora Lichtman talks with Bindi about her family’s legacy, how motherhood fuels her approach to conservation, and what it’s like to run a zoo.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Flora Lickman. Today on the podcast, White Tails are underrated. But first, a chat with conservationist, Bindy Irwin, daughter of The Crocodile Hunter. We described Dad as a living hurricane. Like, he was a living hurricane just like stuffed inside a person. More than 20 years ago, conservationists Terry and the late Steve Irwin, captured the world's attention with their show, The Crocodile Hunter. Hey, hey, hey, hey, what's going on here?

This crock is going ballistic. Woo-hoo! I can't believe this. Every way I turned my goggles, I can see sharks. It's right me it was dangerous. It introduced millions of people to the Australia Zoo and the strange and sometimes scary wildlife from down under. Now their daughter, Bindy Irwin, runs the zoo with her family and has taken up the conservation mantle. Her new book is called You Are a Wildlife Warrior, Saving Animals and the Planet. In it, she takes young readers on an adventure through the zoo, along with her daughter, Grace.

Bindy, welcome to Science Friday. Thank you so much, Gidei. I'm so happy to be here. Let's talk about your new book. What made you want to write it? Oh, my goodness. I am so excited and so proud of my book. I have to say, this book all came about because of our beautiful daughter, Grace. I held our gorgeous daughter in my arms for the first time and went, oh my goodness, I can't even imagine the amazing life ahead of her. And here at Australia Zoo, our whole world revolves around conservation.

Pretty much, it's not just what we do, it is who we are, our conservation work. And I had a small feeling that our daughter would love wildlife and wild places as well. And of course, we would have supported her, you know, if you're not. If she didn't, absolutely. But as she... How old is she now, Bindy? She is three and a half. And as she's grown up, she has only gotten more excited and more involved in all of our conservation

work. And boy, does she love animals. It is so beautiful to see. So this book kind of bloomed from there and hopefully inspiring the next generation of wildlife warriors to appreciate and explore our gorgeous Mother Earth. Well, I have a three and a half year old myself. Oh my goodness. So you know, you know this is a time for discovery, big emotions, all the things. Congratulations. You too. It is wonderful to see the world through three and a half year old eyes sometimes.

Yes, definitely. We wear their hearts on their sleeves, that's for sure. We always say we never have to wonder what Grace is thinking. She will tell you. In the book, you invite your readers to be wildlife warriors. Where did that? term come from? Well, the term wildlife warriors actually originated from my dad. My dad first created that term and it has just become our family's motto. It means so much to us. Being a wildlife warrior means to stand up and speak for those who cannot speak for themselves and to make a difference for the planet. I was watching some old clips of your dad, Steve Irwin, who was just so engaging, of course, to watch. Thank you.

And I was thinking about how he brought this sort of, you know, for lack of a better term, and you might have a better term for it. But this sort of like wild man energy to conservation. Like there's, you know, shredding guitars and crock wrestling. And I wondered whether, you know, that was a conscious choice, like a strategy to bring people into conservation who might not otherwise care about animals or about crocodiles. I don't know. What do you think? I do. I do like, was it a strategy? I, I appreciate, I appreciate the question, thank you,

but I have to tell you, that was, that was dad to his very core. I mean, what you saw, what you saw on camera, there was no strategy there. That was 100% him, 100% of the time, truly, like he, he was the most passionate. We described dad as a living hurricane, Like, he was a living hurricane just, like, stuffed inside a person. He was, he was always, always so passionate about everything that he did. And, you know, when you're a kid and you see something amazing, you fully embrace it and go, Gricky, this is amazing, and get excited about it. And I remember growing up, like, that is who he was.

We would wake up in the morning, and he started his day of work at about, oh, 2,000. 30 in the morning. Like he couldn't sleep. He had, he had just so much he wanted to get done. He'd burst through the door in the morning and go, you know, we're heading out to Windora. We're going to do research with fear snakes or we're going to go climb a mountain. And he just, he never stopped. And he was so passionate about everything that he did. And truly what you saw on camera was who he was. And I feel like so many people lose that sense of, of wonder. and inspiration and awe for our world. And Dad didn't lose that.

Here's something interesting. Dad, we all talk about live every day as if it's your last. And Dad really did. In fact, after he got done doing some incredible wildlife thing that we were often there for, whether it was feeding a crocodile

or swimming with whale sharks, he would go, well, now I can die. And he meant it. He was like, this was such a, an incredible moment in my life that if I'm gone today, I feel, I feel completely happy and at peace and am grateful for the experience. And oh my goodness, we all talk about living each day as if it's our last, but we should, we should, we should actually feel that sense of wonder in our world and do things that genuinely make us happy. Yeah, I really appreciate that lesson that he taught me

without realizing it, I think. And as I've grown up, I've come to realize it more and more. He led by example, and I love that about him. It is a very powerful way to live, and it's also very rare, I think. It is. It is very rare. It's very much easier said than done, I think. Yes. Yes. The book centers you and your daughter. You're speaking to her in it. Has becoming a parent changed the way that you think about conservation? Oh, absolutely. It has become so much more important to me. After having grace, you know, you think about this little person and what future they are going to have on the planet.

I want to do everything in my power to make sure that grace and the future generations are going to live in a world with clean air and fresh drinking water and an abundance of wildlife. I want to talk a little bit about the zoo and just what it's like. like to live on the grounds, what it's like to run a zoo. Give me a day in your life. Oh my goodness. Well, thank you for asking that. It's, um, it is never a dull moment. It is always very exciting. So our family, we live and work within Australia Zoo. It's a family run business. So we are, we are busy. I will say it is busy. For those of you thinking about running a zoo, you probably won't

sleep much. Really? But that's okay because you'll be very fulfilled. You'll be like, this is great. No, but in all truth, it is, it is wonderful and every day is completely different. The only, my dad, this is why my dad was so passionate. The only way you're going to get people to genuinely want to make a difference is first by showing them what they should be protecting, showing them how a lemur makes the cutest

little chewing noises when it eats its food, how an echidna actually has the funniest little, like, fluff between its little spiky quills and all of these, all of these things that, you know, you wouldn't know if you just read about it in a book. And what, oh my goodness, what an experience to watch people. Like, I have taken a lot of people on many tours of Australia Zoo and watching people genuinely connect with an animal to see that life. in their eyes as they realize how amazing it is to have a mere cat standing on your head. And then their questions leading on from that, how can I help protect mere cats? How can I make a difference for them?

It is truly inspiring. But gosh, Australia is a, you have to come visit us now. Please come see us. I do anything to see a wombat. I have to tell you. I can make that happen. They are so fun. Trust me, as long as you have a sweet potato, the wombats will be your best friends.

I'll come in my pockets are going to be stuffed with them. Yeah. Bindy, thank you so much for joining me today. Thank you. It has been so lovely to talk to you. And I feel like you guys are helping people to accidentally learn something along the way, which is just brilliant. That is our goal. We want to help people accidentally learn things every week. Bindy Irwin is the author of You Are a Wildlife Warrior, Saving Animals and the Planet, and a conservationist at the Australia Zoo. After the break, why tails are great and why a better tail could make a better robot. I just think there's more to the tail than we've been giving it credit.

They're more than just a little floofy thing. Stick around. It has been a busy news week, and we're going to start out with some counter-programming. We are talking tails. If you have ever met a cat, you've probably at some point been amazed by how acrobatic they are. They can reorient themselves effortlessly, even in midair. It turns out that a lot of that twistiness comes down to having a top-tier tail. Writing this week in the journal Royal Society Interface, researchers explore the mechanics of different tales, from reptiles to mammals, and consider how a better tail could help build a better robot. Joining me now to untwist all of this science are Dr. Talia Moore, Assistant Professor of Robotics and Mechanical Engineering at the University of Michigan in Ann Arbor, and Dr. Carey Weber, a postdoc in Kim Cooper's lab in the Department of Cellular and Developmental Biology at UC San Diego. Welcome to you both to Science Friday.

Thank you. I'm so thrilled to be here. Hi, I'm happy to be here. Talia, you're a roboticist. Why do you care about tails? Yeah, tails are just a multifaceted appendage. You can do a lot of different things with your tail than you can with your legs. And so it just kind of gives you this extra umph, a little pizzazz to the things that a robot can do. Carrie, you're a developmental biologist. what do tails mean to you? I love that tails can be looking so different to do so many different

things, but they have a really shared similar embryonic origin. So they're kind of made the same way. They happen at the same point in development, whether it's a human or a cat or a mouse or a giraffe. But they all look really different. They're different sizes. Their vertebrae are different shapes. and I just am mystified by how evolution and ecology and genetics can make this organ look so different. You're mystified by the mystery of the tail. I am. It's not a mystery I had ever considered, I have to say, until this paper. So thank you for giving me something new to think about.

Talia, what did you find with this new study? In our paper, we have a simulation environment to try and understand how tails can be used as inertial appendages. And the way I like to explain that is if you're a tightrope walker and you're walking on your tightrope, you have this really long stick. And if you start to lose your balance, you rotate that stick and it kind of rotates your body so you can get back onto that tightrope. And that stick is your inertial appendage. And a paper that I wrote a while back showed that lizards can do this with their tail to rotate their body when they're jumping in midair. And that tail, we modeled it as a single rigid rod. And that inspired a lot of robots, but they've all been

kind of single rigid rods moving in one plane. Which is not actually true for many tails, right? Right. And so we started looking at mammals and seeing, wow, they're tails, they're making all these complex curves in 3D space. And we started to investigate, what if the joints and the tails and the curve of the tail is actually what's helping these tails act as better inertial appendages, even though they're skinny and don't have the moment of inertia themselves. So we did this simulation to try and compare the effectiveness of different types of tails, which has never been done before. Is this shape of your tail better than this shape of your tail and going to be able to move your body more effectively? So we came up with this.

this optimization program. And then once we figured out that joints were really helpful, then we said, okay, what if we allow the bones to change size, but the total tail length to be the same? And so when we did that optimization, we actually found that there's like this really sharp crescendo and then a sharp day crescendo. So the bones get a little bit longer and then they get shorter. And when we look at the real tails that Carrie shared with us, we find that animals that use their tails as inertial appendages have that exaggerated crescendo, day crescendo, more than the tails of animals who don't use their tails as inertial appendages. Okay, so where the tail attaches to the body, the bones are short, and then they get longer, and then they get shorter again.

Exactly. Carrie, after all these simulations, I mean, you were in the music. museum archives, tail spawning. What were you looking for? So I had also noticed this crescendo pattern in mice and the rodents that we study in the laboratory. And I wanted to know if this pattern was in all mammals. And so I was just a menace measuring as many tails as I could get my hands on in the museum archives. And then we were talking with Talia about this paper because we had already been collaborating and talking about tails. And it was really, really exciting to find that they had found this pattern in the simulations and I was finding these patterns in the museum archives. But it turns out there's lots of different patterns and we don't know what those patterns do yet.

We're really excited to figure it out. Carrie, in your opinion, what is the top tail in the animal kingdom? The tail of all tails. I can tell you my personal favorite, which is the silky ant eater. And that one stands out because most of the tails that we've measured, the complete ones, average out around like 30 vertebrae that tends to be what most of them are making, whether they're prehensile or they're using them for inertial maneuvering. But the silky ant eater tail that we measured had 41 vertebrae in it, which it's the longest one in our data set. I remember when I pulled

the skeleton out of the box, I was in awe of how many vertebrae. Did you gas? Or in the tail. I did. I did gas. But it's a very cool animal. It's an ant eater, but it's mostly living in trees, and it has a prehensile tails. So in pictures of it, you can see it grasping and holding onto branches. It's very cool. So, Talia, should we expect robots with anteater tails? Like, is that what you're thinking? Yeah, I think there are some folks who are working on prehensile tales right now.

I saw one at a conference last year. And so I think they're closer than you think. Really? Mm-hmm. I mean, a robot with a tail sounds creepy to me. There are actually a lot of robots with tails that are out in the world right now, and I think they're pretty cute. The benefit of these tails is they can make tighter turns.

They can recover from external perturbation. So if something bumps them as they're walking, the tail helps them recover. And there's even like a little like RC car with a tail on it that can drive up off of a ramp and do a barrel roll with its tail. Well, this is a thing I've been wondering since reading your paper. Should we be attaching tails to more things? Yes. Why not? Would that be helpful? If I had a tail, what would I be able to do that I can't do now?

Yeah. So as I was walking the dog this morning, I slipped on the ice. And if you had a tail, you'd probably be able to prevent yourself from falling in a really damaging way. You'd probably be able to regain your balance pretty quickly. Would I be an Olympic gymnast if I had a tail? Yes. I was watching the Olympics and those ladies on the balance beams. I watched them using their arms and legs as inertial appendages, and it was amazing to see. Carrie, if tails are so great, why do I not have one? It probably has to do with how us humans stand and how we walk and move. This is a huge area of study in bioanthropology and primatologists and understanding why great apes and humans don't have a tail anymore.

And I would argue that we do. We have a tiny little tail bone. and we have a few tail vertebrae that fuse into our pelvis. And actually as embryos, we make a tail and it just goes away, probably through apoptosis, so cell death, and it retracts a little bit into the body. So making a tail is a part of all of our embryonic programs. We just don't make one outside of our bodies. And even though we don't have an external tail, we still have a lot of those muscles that control the tail.

And so I'm learning a lot about those when I go to physical. physical therapy. And the pelvic floor. That's where a lot of them have ended up. Wait, really? Yeah. Yeah. Absolutely. So if I'm doing my pelvic floor exercises, I'm actually activating my tail muscles. Yeah, you are. We're doing dissections and we're looking at all of the muscles that control mammal tails. And I'm working those same muscles in physical therapy. A lot of women are going to be interested in this. Yes, definitely. Tahlia, can knowing about different tails help you make a super tail for your robot, like something even better than what you see in nature? Yes. So this is exactly what I teach in my bio-inspired robotics course. So if we understand the principles, like the underlying

physics principles and the mechanics of how the animals are doing something, and we understand their evolution, we can identify that maybe this animal tail is constrained because maybe of its lineage, it has this certain constraint. Maybe it's used for 25 different things. And so it's not going to be the best at anything. But if we understand that underlying principle, we can abstract that and transfer it to an engineering system and make something that's even better than the biological system.

So in the first lizard paper that we had, we were able to make a tail that was more effective than both a lizard that we were studying in the lab and a simulation of a velociraptor. Really? Yeah. Why do you all care about this? Yeah.

My background is biomechanics. I want to know how biology, like biological things, move in the world. And what are the underlying principles of movement that are fundamental and can be applied to all sorts of different species? And so it's really cool to me that many different animals have evolved a tail that is capable of really good inertial maneuvering. And it's not just tails. Like there are other animals. There's a study showing that bats use their wings as inertial appendages and prey mantises use their arms and legs as inertial appendages. So I'm really excited to learn about the diversity of the morphology of these inertial appendages and how the morphology affects their effectiveness as that inertial

appendage. What about for you, Carrie? I think tails are such a cool, diverse appendage that have not been given a lot of attention in biology and how they develop and they take shape, especially because they are so diverse. And our namesake, we are vertebrates. We are defined by our axial skeleton and our spine. And it is really diverse. Like you think of giraffes. and humans have the same number of vertebrae in our necks, but giraffe necks are really, really long, and that's just because the vertebrae become much longer. So there's all of this incredible diversity in our vertebral skeleton, and I think the tail is an amazing model to study what sort of ecologies and movements and genetics drive those differences. And I just think

there's more to the tail than we've been giving it credit. Well, thank you. I could nerd out for tales of forever. So I appreciate it. Thanks for coming on the show. Thanks for having us. Thank you so much. Dr. Talia Moore, assistant professor of robotics and mechanical engineering at the University of Michigan in Ann Arbor, and Dr. Carrie Weber, a postdoc in Kim Cooper's lab, in the Department of Cellular and Developmental Biology at UC San Diego. And that is about all we have time for. Lots of folks helped make the show happen, including... Praise, I gochi. Sandy Roberts. Robin Casmer.

Jordan Smudjick. I'm Flora Lichtman. Thanks for listening.