Hi, it's Jane. Every summer, my family makes a list of the things we want to do while the weather is warm. It includes things like how many different lakes we want to jump into, what animals we hope to see, and new crafts we want to try out. This summer, But Why has made a summer bucket list and an invitation to you to join the But Why fan club, so you can get it. New members of the fan club will get a special But Why Summer Adventure Kit with a notebook, a magnifying glass, a drawstring bag, and a list of fun summer activities and adventures to have together. With a $10 a month donation, you're supporting all we do at But Why to explore and encourage curiosity and learning, and you're getting the Summer Adventure Kit. Check it out and make your gift at butwykids.org. This is But Why, a podcast for curious kids from Vermont Public. I'm Jane Lindholm. Today, we have a bonus episode for you all about some very special lizards. We're picking up right where we left off last week, down in the basement of the San Diego Natural History Museum. I went there to talk with Adam Claus, who manages the herpetology collection at the museum. Herpetology is the study of reptiles and amphibians, which is actually kind of an odd pairing as it turns out, because reptiles and amphibians aren't actually all that closely related. It's really just a historical thing that has been carried through to the present day, so it dates back to the founder of taxonomy, Carolus Linnaeus. I don't know if anybody's heard of him, but he's the one who sort of created the system of scientific names for animals, which can always consist of two parts, right? He considered anything that didn't have blood that could control its own temperature. The way we control our own blood temperature, reptiles and amphibians do not. He considered anything that didn't have these characteristics as very primitive, creepy, disgusting organisms. Just by virtue of that very arbitrary classification, reptiles and amphibians were lumped together, even though they're not necessarily each other's closest relatives. Birds are actually more closely related to reptiles, because they actually are a type of reptile, but we don't study birds in herpetology. That sort of got pulled out, and it's the ornithologists who study that. It's this weird mix. These are not necessarily animals that are all that similar. They're not all that closely related, but we continue to study them in this way today. And for me, it's really exciting because I get to study a very diverse group of animals. It's hard to imagine a very, a more different group of animals than frogs and snakes, right? But these are all lumped together, and so it's a very exciting group of animals to work with and to study. We went to see Adam because you all have sent us a lot of questions about lizards, and you've sent us so many lizard questions, in fact, that we couldn't even fit them all in one episode. So we started last week and we're back today. And in this bonus episode, we're going to narrow our focus even more from reptiles to lizards to specific types of lizards. And a lot of you have questions about one of the most famous lizards, the chameleon. And when I say a lot of you, I mean a lot of you. Hi, my name is Jonathan. I'm six years old and I'm from Australia. My question is, how do chameleons change color? Bye. Hi, my name is Noah. I live in New Hampshire and I'm four years old. My name is Hank. I live in Lubbock, Texas. I am about to be six. My name is Warlite and I'm five years old and I live in New York and I want to know what colors do chameleons change? My name is Jasper. I'm eight years old and I'm from Pennsylvania. Hi, my name is Luke. I'm eight years old and I live in Hong Kong. My name is Clara. I'm seven years old. I live in St. Paul, Minnesota. I'm Miko. I am six years old. I live in St. Gean, Texas. Hi, my name is Blair and I live in New Jersey and I'm six years old. My name is Henry and I am eight years old. I live in Georgetown, Texas. My name is Lucy and I live in Connecticut and I'm six years old. Hi, my name is Holly. I'm from Calgary, Alberta. I'm seven years old. My name is Safer, Hank, and I'm from Newton, Massachusetts. How old are you? Um, and I'm six years old. Hi, my name is Sadie and I'm eight years old and I'm from Munster, Indiana. My name is Kellan. I am eight years old. My name's I'm six years old. I live in Baltimore. My name is Caroline and I live in Houston, Texas and I am six years old. Hi, my name is Berkeley. I live in San Antonio, Texas. I'm eight years old, almost nine. Hello, my name is Harlan. I'm a finance man in Colorado. I'm five. My question is what happens inside chameleons body when they turn color? My name is Webb and I live in Ebling, Texas and I am six years old. My name's Dashel and I am from Durham, North Carolina and I am six years old. I live in Texas, Michigan and my age is three and a half. My name is Anakin. My name is Leo and I'm four years old and I'm from North Charleston, Maine. Hi, my name is Bren and I am seven years old and I live from Brad from Vermont. Hi, my name is Vivian. I am six years old. I live in Michigan. Hello, my name is Asher. I am five years old. I'm from Mill Bay, California. Hello, my name is Judy. I'm from Chicago. I am nine years old. My name is Riley. I'm five years old. I live in Longmont, Colorado. My name is Shayna. My age is six. I live in Woodinville, Washington. Hello, my name is Miles. I'm six years old and I'm calling from South Africa in Pretoria. My name is Will and I'm four years old and I live in Woodin, Montana and my nickname is How does chameleons change colors? I want to start by saying that it's important to remember that there's not just one type of chameleon out there. There's actually hundreds of different types of chameleons and they can range from really big like the size of your bearded dragon to smaller than your pinky finger. So there's a lot of diversity within chameleons but one of the things that they share is that they can all to some degree or another they can change the patterning on the surface of their skin and the way they do that is on there in the individual scales of their skin there are these little packets of pigment and these packets of pigment can sort of be expanded or contracted through muscular action and nerve endings and so the lizards can expand or contract all over their skin sort of all at the same time all these little tiny pinpricks worth of color that are in their scales and by changing whether they're expanded or contracted they can show certain colors or conceal other colors and through that mechanism they can sort of become whatever they want to in a way. If you want to know more about how chameleons change their color we have a video episode all about it. If you ask your adults to help you get to But Why Kids on YouTube you can watch me change color. Coming up Komodo Dragons, Green Iguanas and Tuataras oh my! This is But Why and today we're learning all about lizards with herpetologist Adam Kloss who manages a collection of 80,000 reptile and amphibian specimens at the San Diego Natural History Museum. He's helping us learn about some very specific kinds of lizards today. We've gotten a lot of questions about Komodo Dragons and I share your interest in them. Kids are curious about is a Komodo Dragon. Yeah so Komodo Dragons are the the largest lizard that currently lives on planet earth so they can be well over 20 feet long. They're only found on a few small islands in Indonesia which is in Southeast Asia. They're really remarkable animals in many ways not just because of their size they're also really interesting because they have bacteria in their mouth as well as actual venom in their salivary components. So you don't want to get bitten by one? For both reasons no. They have very dirty mouths and they have venomous mouths as well and so they're using that combination of bacteria and venom to help subdue their prey and so they'll often eat really large things like water buffalo and so they will sort of bite a water buffalo, break some blood vessels, and introduce both the bacteria and the venom into the animal's bloodstream. It's getting a little bit gruesome, maybe too gruesome but they're you know. Nothing's too gruesome for us. And so the animal basically they're they're anti-coagulant compounds so the animal the blood doesn't coagulate and so the blood just continues to flow from that wound until the animal then loses consciousness and then the Komodo dragon's using its very long forked tongue to track where that prey animal went and where it died and then they follow it to that point and then they finish eating it at that point. Hi I'm Max and I was in Presidio of Utah and I am eight years old and my question is why are Komodo dragons called Komodo dragons if they're not a dragon? Hello my name's Summer and I'm an important Oregon and I'm four and a half years old and why are Komodo dragons called Komodo dragons? Are they real good dragons? The Komodo part comes from the Indonesian island of Komodo where Europeans and Americans first saw these lizards. People who lived on the islands where these giant reptiles roam called them aura meaning land crocodiles. The visiting scientists thought these creatures had a fearsome reputation and they're really really big so they called them dragons. My name is Quincy I'm eight years old and I live in Austin Texas how do Komodo dragons survive when they're endangered? There are a lot of factors why Komodo dragon populations are declining including things like habitat loss and poaching and natural factors like earthquakes volcanoes and fire. Climate change is another big factor that threatens their survival. A lot of people are working to protect Komodo dragons and the largest population of these lizards are in the Komodo National Park where they have protected status. My name is Zashla and I live from Rockville, and I'm four years old. How do Komodo dragons fight on two legs without falling off? They're two hind legs. They just have really good balance so it gets back to that tail so they'll use their tail as a counterbalance and so they'll have by having their tail out extended extended really well that helps keep them from from flopping over. My name is Silas and I'm from Louisville, Kentucky. I'm seven years old and my question is how do Komodo dragons get bacteria in their mouth? It's just part of the bacteria that's just sort of around in their environment and so similar to the way all of us have bacteria in our guts right? They pick that up from the environment part of it maybe comes from their moms. We're not quite sure. Hi my name is Alexandra. I live in Fort Collins, Colorado. My question is how many babies do minotaurs have at a time? Alexandra is wondering how many babies do monitor lizards have at a time? Totally depends. Again similar to chameleons there's no one type of monitor lizard. There's dozens of different monitor species that range from the largest lizard on the planet, the Komodo dragon, to dwarf monitors which are smaller than your bearded dragon and so it depends on the species anywhere from probably a couple eggs to maybe a dozen something like that. All right and one more related question. My name is Will and I live in Atlanta Georgia. My question is if the Komodo dragon is the biggest lizard what is the smallest lizard? There's a number of different competitors for the title of smallest lizard in the world so we talked a little bit earlier about these little dwarf mini-chameleons that are like smaller than your pinky finger so some of those are a good candidate and then there's also these really tiny geckos called dwarf geckos that many of which occur only on islands in the Caribbean and those are also extremely tiny where you could have a full-size adult coil up comfortably on a dime, a U.S. dime. So they're like maybe your biggest fingernail size. Yeah they're really really tiny and what's interesting is that most of these really tiny lizards they live in leaf litter that's their habitat so the same for these you know the tiny chameleons they're in the leaf litter as well as these little tiny geckos on Caribbean islands they're they're hanging around in the leaves falling leaves on the ground. That would be so cute to see. How about iguanas? I'm Hudson and I am five years old and I live in Arvada Colorado and and what my question is is why are iguanas or lizards green most of the time? Mostly it's a camouflage thing so iguanas, green iguanas specifically there are boreal which means they spend most of their lives up in trees and so their green color helps them to camouflage among the leafy branches where they live. Interestingly Hudson green iguanas aren't always green when I was in Florida doing some but why reporting about invasive species a few years ago I saw a lot of big green iguanas that were actually orange. Mature males often turn orange during the breeding season from about December through April. Hi my name is Russon and I was in cherry trees when I was nine five years old and I want to know why do iguanas have freaky things on the back? That's a great question so male green iguanas in particular they're using those spikes as a way to show off to females how healthy and vigorous they are and then it's a little bit of a defensive thing where those those scales can sort of protect against predators but it's mostly for sort of showing off to the females. My name is Wyatt and I am five years old I live in Los Angeles California. My question is why do male iguanas have do laps? Wyatt has obviously learned a little bit about iguanas for people who don't know what a do lap is can you tell us that too? Yeah so a do lap is this sort of thin flexible flap of skin that hangs down from the throat of iguanas they can't really control it it just sort of lays there there are other lizards called anoles which some of you may have heard of and they can actually push their do lap out or retract it flat against their throat in the case of the anoles the do lap is often very brightly colored and so it's mostly male anoles that have these colored do laps or flaps of skin under their throat and they're using them to signal to other males for territorial interactions and also to signal to females hey I'm over here I'm very vigorous I might be a good mate. For iguanas they're more it's just a thing that males have again to sort of signal their vigor so bigger adult male iguanas have bigger do laps and they might make better mates in minds of the female iguanas. Hi my name is Joseph I'm six years old I live in Etiquette City, Maryland. I'm wondering how some gliding reptiles like the Draco lizard glide halfway through the air and catch themselves on trees. This is one of my favorite groups of lizards so if you're listening right now what you can do is you can if you hug yourself not sort of on your shoulders but sort of around your stomach where your hands are positioned they're positioned over your rib cage you can sort of feel your ribs if you press into your body so the Draco lizards the wings that they have are basically they were modified ribs they're modified rib cage so now if you take your arms and you keep your elbows pressed tightly against your sides and you flare your arms out you can imagine that your arms are sort of your ribs and that's what Draco lizards do they can take their ribs from being sort of flat against their bodies and they can flare them out to create these wings effectively wings and they use those wings to then glide from tree to tree in the forest where they live. How do they catch themselves on the tree without smashing into it? So they'll sort of break they'll sort of flare their wings up and catch the air and slow down right before impact but because they're so light these are not large lizards you know they're about the size of fence lizards for those of you who might grow up might have grown up with those they're much smaller than a bearded dragon they're sort of like half the size of a leopard gecko typically and they're very sort of slender so they're not super heavy so they don't have a big impact when they hit a tree after flying from another tree and so they're not creating a lot of force and so they can just sort of plop onto the side of the tree and grab on with their claws and they're good to go. All right one other type of lizard that we have a question or type of animal that we have a question about. Hi my name is Nikki and I'm nine years old I'm from Israel why is Tuatara not a lizard? This is another really good question and so without getting too much into the details it's because they have a bunch of different structures in their skeleton that no lizards have and so Tuatara is branched off on the tree of life before earlier than any other lizard and so they're what we call sister to all other lizards so a good way to think about it is that all true lizards are more closely related to each other than any of them is to the Tuatara. So the Tuatara is sort of this weird offshoot in the tree of life the reptile tree of life and even though they look externally a lot like a lizard there's a number of different features of their ribs of their skull of their teeth that no lizards have and so they're very special in that way. What do they look like? They look kind of like a iguana like a brown iguana they don't grow quite as big as green iguanas and their tail isn't as long but they're sort of spiky they have a crest along their back. To all intents and purposes they sort of just look like a big lizard but they are not lizards. Is there anything else that you think kids should know about lizards? A lot of us are very interested in them but you know what's something that you could send us off with as something else to think about or investigate on our own about lizards? Yeah so one of the things that I'm really interested in and is really important to me is making sure that we're trying to do our best to keep lizards around. A lot of lizards are in trouble all across the world and Southern California is no different and one of the biggest things that anybody can do to help protect lizards is to not use pesticides in your gardens. So pesticides typically kill insects and most lizards feed on insects and so if you're killing off all the insects the lizards have nothing to eat and they disappear. So by not using pesticides you will help out your local lizards and I think we all stand to benefit from that. That's a great place to end it. Thanks so much to Adam Claus, collections manager of herpetology at the San Diego Natural History Museum. We loved going to see the reptile and amphibian specimens in the museum's collection. As you know you can ask us a question on just about anything. Have your adult help you record you asking the question? They can use a free voice app that comes on a smartphone then send it to questions at butwhykids.org. But why is made at Vermont Public and distributed by PRX? Our producers are Sarah Bake, Melody Baudette and me Jane Lindholm. Joey Palumbo is our video producer and Luke Reynolds wrote and performed our theme music. If you like our show please give us a review or a like on whatever platform you use to listen to us. We'll be back in one week with an all-new episode. Until then stay curious.