1 00:00:19,800 --> 00:00:22,980 Jane: This is But Why: A Podcast for Curious Kids from Vermont 2 00:00:22,980 --> 00:00:26,565 Public. I'm Jane Lindholm. Today, we have a bonus episode 3 00:00:26,565 --> 00:00:30,765 for you all about some very special lizards. We're picking 4 00:00:30,765 --> 00:00:33,885 up right where we left off last week, down in the basement of 5 00:00:33,885 --> 00:00:37,245 the San Diego Natural History Museum. I went there to talk 6 00:00:37,245 --> 00:00:40,425 with Adam Clause, who manages the herpetology collection at 7 00:00:40,425 --> 00:00:43,845 the museum herpetology is the study of reptiles and 8 00:00:43,845 --> 00:00:47,910 amphibians, which is actually kind of an odd pairing, as it 9 00:00:47,910 --> 00:00:53,070 turns out, because reptiles and amphibians aren't actually all 10 00:00:53,070 --> 00:00:54,510 that closely related. 11 00:00:54,810 --> 00:00:57,510 Adam: It's really just a historical thing that has been 12 00:00:57,510 --> 00:01:00,570 carried through to the present day. So it dates back to the 13 00:01:00,570 --> 00:01:04,050 founder of taxonomy, Carolus Linnaeus. I don't know if 14 00:01:04,050 --> 00:01:06,870 anybody's heard of him, but he's the one who sort of created the 15 00:01:06,870 --> 00:01:10,230 system of scientific names for animals, which can always 16 00:01:10,230 --> 00:01:14,475 consist of two parts, right? And so he considered anything that 17 00:01:14,475 --> 00:01:17,955 didn't have sort of blood that sort of control its own 18 00:01:17,955 --> 00:01:20,355 temperature. So the way we control our own blood 19 00:01:20,355 --> 00:01:22,875 temperature, reptiles and amphibians do not, and so he 20 00:01:22,875 --> 00:01:25,095 considered anything that sort of didn't have these 21 00:01:25,095 --> 00:01:28,095 characteristics as very primitive, sort of creepy, kind 22 00:01:28,095 --> 00:01:31,875 of disgusting organisms. And so just by virtue of that very 23 00:01:31,875 --> 00:01:34,935 arbitrary classification, reptiles and amphibians were 24 00:01:34,935 --> 00:01:37,200 lumped together, even though they're not necessarily each 25 00:01:37,200 --> 00:01:40,200 other's closest relatives. So birds are actually more closely 26 00:01:40,200 --> 00:01:43,440 related to reptiles, because they actually are a type of 27 00:01:43,440 --> 00:01:46,500 reptile, but we don't study birds in herpetology that sort 28 00:01:46,500 --> 00:01:49,380 of got pulled out, and it's the ornithologists who study that. 29 00:01:49,620 --> 00:01:52,980 So it's this weird mix. These are not necessarily animals that 30 00:01:52,980 --> 00:01:56,220 are all that similar, they're not all that closely related, 31 00:01:56,640 --> 00:01:59,985 but we continue to study them in this way today, and for me, it's 32 00:01:59,985 --> 00:02:02,865 really exciting, because I get to study a very diverse group of 33 00:02:02,865 --> 00:02:05,925 animals. It's hard to imagine very, a more different group of 34 00:02:05,925 --> 00:02:09,405 animals than frogs and snakes, right? But these are all lumped 35 00:02:09,405 --> 00:02:11,985 together, and so it's a very exciting group of animals to 36 00:02:12,105 --> 00:02:13,125 work with and to study. 37 00:02:13,305 --> 00:02:15,945 Jane: We went to see Adam because you all have sent us a 38 00:02:15,945 --> 00:02:19,710 lot of questions about lizards, and you've sent us so many 39 00:02:19,710 --> 00:02:23,370 lizard questions, in fact, that we couldn't even fit them all in 40 00:02:23,370 --> 00:02:27,210 one episode. So we started last week, and we're back today, and 41 00:02:27,210 --> 00:02:29,910 in this bonus episode, we're going to narrow our focus even 42 00:02:29,910 --> 00:02:34,650 more from reptiles to lizards to specific types of lizards. And a 43 00:02:34,650 --> 00:02:37,890 lot of you have questions about one of the most famous lizards, 44 00:02:38,010 --> 00:02:43,635 the chameleon. And when I say a lot of you. I mean a lot of you. 45 00:02:43,815 --> 00:02:46,695 Jonathan: Hi, my name is Jonathan. I'm six years old, and 46 00:02:46,695 --> 00:02:50,955 I'm from Australia. My question is, how do chameleons change 47 00:02:50,955 --> 00:02:51,975 color? Bye! 48 00:02:51,975 --> 00:02:57,495 Noah: Hi. My name is Noah. I live in New Hampshire, and I'm 4 49 00:02:57,495 --> 00:02:58,395 years old. 50 00:02:58,395 --> 00:03:07,560 Hank: My name is Hank. I live in Lubbock, Texas. I am about to be 51 00:03:07,560 --> 00:03:08,280 six. 52 00:03:08,280 --> 00:03:14,100 Lorelai: My name is Lorelai, and I'm five years old, and I live 53 00:03:14,100 --> 00:03:21,420 in New York, and I want to know what colors do chameleons 54 00:03:21,420 --> 00:03:22,380 change? 55 00:03:22,560 --> 00:03:26,040 Joseph: My name's Jasper. I'm eight years old and I'm from 56 00:03:26,280 --> 00:03:27,060 Pennsylvania. 57 00:03:27,060 --> 00:03:31,005 Luke: Hi, my name is Luke. I'm eight years old, and I live in 58 00:03:31,005 --> 00:03:31,485 Hong Kong. 59 00:03:31,485 --> 00:03:36,585 Clara: My name is Clara. I'm seven years old. I live in St 60 00:03:36,585 --> 00:03:37,545 Paul, Minnesota. 61 00:03:37,545 --> 00:03:43,245 Mikko: I'm Mikko. I am six years old. I live in Seguin, Texas. 62 00:03:43,305 --> 00:03:47,625 Blair: Hi, my name is Blair, and I live in New Jersey, and I'm 63 00:03:47,625 --> 00:03:48,525 six years old. 64 00:03:48,645 --> 00:03:50,925 Henry: My name is Henry, and I am eight years old. I live in 65 00:03:51,165 --> 00:03:52,230 Georgetown, Texas. 66 00:03:52,290 --> 00:03:56,790 Lucy: My name is Lucy, and I live in Connecticut, and I'm six 67 00:03:56,790 --> 00:03:57,390 years old. 68 00:03:57,390 --> 00:04:04,290 Holly: Hi, my name is Holly. I'm from Calgary, Alberta. I'm seven 69 00:04:04,290 --> 00:04:04,770 years old. 70 00:04:04,830 --> 00:04:09,270 Abraham: My name is Abraham, and I'm from Newton, Massachusetts. 71 00:04:09,270 --> 00:04:10,110 Adult: How old are you? 72 00:04:10,290 --> 00:04:12,210 Abraham: And I'm six years old. 73 00:04:12,210 --> 00:04:16,395 Sadie: Hi, my name is Sadie, and I'm eight years old, and I'm 74 00:04:16,395 --> 00:04:17,895 from Munster, Indiana. 75 00:04:17,894 --> 00:04:21,974 Kevin: My name is Kevin. I am eight years old. 76 00:04:22,095 --> 00:04:27,255 Otis: My name is Otis. I'm six years old. I live in Baltimore. 77 00:04:27,375 --> 00:04:30,855 Caroline: My name is Caroline, and I live in Houston, Texas, 78 00:04:31,275 --> 00:04:32,775 and I'm six years old. 79 00:04:32,835 --> 00:04:36,735 Berkeley: Hi, my name is Berkeley. I live in San Antonio, 80 00:04:36,795 --> 00:04:41,700 Texas. I'm eight years old, almost nine. 81 00:04:41,700 --> 00:04:45,480 Harlan: Hello. My name is Harlan. I work in Aspen in 82 00:04:45,480 --> 00:04:50,580 Colorado. I'm five. My question is, what happens inside 83 00:04:50,640 --> 00:04:54,060 chameleon's body when they turn color? 84 00:04:54,060 --> 00:04:59,460 Webb: My name is Webb, and I live in Abilene, Texas, and I am 85 00:04:59,460 --> 00:05:00,660 six years old. 86 00:05:00,705 --> 00:05:06,045 Dashel: My name is Daschle, and I am from Durham, North 87 00:05:06,045 --> 00:05:09,585 Carolina, and I am six years old. 88 00:05:09,585 --> 00:05:12,285 Atticus: I live in Rochester Hills, Michigan, and my age is 89 00:05:12,285 --> 00:05:14,745 three and a half. My name is Atticus. 90 00:05:14,865 --> 00:05:18,585 Leo: My name is Leo, and I'm four years old, and I'm from 91 00:05:19,245 --> 00:05:19,725 Maine. 92 00:05:19,965 --> 00:05:23,205 Brandon: Hi. My name is Brandon, and I am seven years old, and I 93 00:05:23,205 --> 00:05:24,810 live from Bradford, Vermont. 94 00:05:24,810 --> 00:05:28,050 Vivian: Hi, my name is Vivian. I am six years old. I live in 95 00:05:28,050 --> 00:05:28,710 Michigan. 96 00:05:28,710 --> 00:05:33,570 Asher: Hello, my name is Asher. I am five years old. I am from 97 00:05:34,230 --> 00:05:36,030 Millbank, California. 98 00:05:36,030 --> 00:05:40,050 JD: Hello. My name is JD. I'm from Chicago. I am nine years 99 00:05:40,050 --> 00:05:40,350 old. 100 00:05:40,350 --> 00:05:47,055 Riley: My name is Riley. I'm five years old. I live in 101 00:05:47,235 --> 00:05:49,335 Longmont, Colorado. 102 00:05:49,515 --> 00:05:54,555 Jane: My name is Jane. My age is six. I live in Woodinville, 103 00:05:54,555 --> 00:05:55,395 Washington. 104 00:05:55,515 --> 00:06:00,195 Miles: Hello. My name is Miles. I'm six years old, and I'm 105 00:06:00,195 --> 00:06:03,735 calling from South Africa and Pretoria. 106 00:06:03,735 --> 00:06:08,115 Will: My name is Will, and I'm four years old, and I live in 107 00:06:08,295 --> 00:06:12,855 Virginia. How do chameleons change color? 108 00:06:12,855 --> 00:06:17,355 Adam: I want to start by saying that it's important to remember 109 00:06:17,355 --> 00:06:19,980 that there's not just one type of chameleon out there. There's 110 00:06:19,980 --> 00:06:22,740 actually hundreds of different types of chameleons, and they 111 00:06:22,740 --> 00:06:25,620 can range from really big, like the size of your Bearded Dragon, 112 00:06:25,920 --> 00:06:28,920 to smaller than your pinky finger. So there's a lot of 113 00:06:28,920 --> 00:06:31,380 diversity within chameleons, but one of the things that they 114 00:06:31,380 --> 00:06:35,505 share is that they can all to some degree or another, they can 115 00:06:35,505 --> 00:06:38,685 change the patterning on the surface of their skin, and the 116 00:06:38,685 --> 00:06:42,585 way they do that is on their in the individual scales of their 117 00:06:42,585 --> 00:06:46,065 skin, there are these little packets of pigment, and these 118 00:06:46,065 --> 00:06:49,665 packets of pigment can sort of be expanded or contracted 119 00:06:49,725 --> 00:06:53,265 through muscular action and nerve endings. And so the 120 00:06:53,265 --> 00:06:57,150 lizards can expand or contract all over their skin, sort of all 121 00:06:57,150 --> 00:06:59,670 at the same time, all these little, tiny pinpricks worth of 122 00:06:59,670 --> 00:07:02,850 color that are in their scales. And by changing whether they're 123 00:07:02,850 --> 00:07:06,390 expanded or contracted, they can show certain colors or conceal 124 00:07:06,390 --> 00:07:09,510 other colors. And through that mechanism, they can sort of 125 00:07:09,510 --> 00:07:11,370 become whatever they want to, in a way. 126 00:07:11,370 --> 00:07:14,250 Jane: If you want to know more about how chameleons change 127 00:07:14,250 --> 00:07:17,850 their color, we have a video episode all about it, if you ask 128 00:07:17,850 --> 00:07:21,255 your adults to help you get to but why kids on YouTube, you can 129 00:07:21,255 --> 00:07:25,455 watch me change color. Coming up, Komodo dragons, green 130 00:07:25,455 --> 00:07:27,615 iguanas and Tuataras. Oh my! 131 00:07:28,755 --> 00:07:31,935 This is But Why. And today, we're learning all about lizards 132 00:07:31,935 --> 00:07:35,235 with herpetologist Adam Clause, who manages a collection of 133 00:07:35,235 --> 00:07:38,835 80,000 reptile and amphibian specimens at the San Diego 134 00:07:38,835 --> 00:07:42,300 Natural History Museum. He's helping us learn about some very 135 00:07:42,300 --> 00:07:45,960 specific kinds of lizards today. We've gotten a lot of questions 136 00:07:45,960 --> 00:07:49,260 about Komodo dragons, and I share your interest in them. 137 00:07:49,740 --> 00:07:53,400 Kids are curious about is a Komodo dragon? 138 00:07:53,460 --> 00:07:57,420 Adam: Yeah. So Komodo dragons are the largest lizard that 139 00:07:57,420 --> 00:08:01,020 currently lives on planet Earth. So they can be well over 20 feet 140 00:08:01,020 --> 00:08:05,145 long. They're only found on a few small islands in Indonesia, 141 00:08:05,145 --> 00:08:08,745 which is in Southeast Asia. They're really remarkable 142 00:08:08,745 --> 00:08:11,805 animals in many ways, not just because of their size. They're 143 00:08:11,805 --> 00:08:15,465 also really interesting because they have bacteria in their 144 00:08:15,465 --> 00:08:20,385 mouth as well as actual venom in their salivary components. 145 00:08:20,865 --> 00:08:22,725 Jane: So you don't want to get bitten by one. 146 00:08:22,845 --> 00:08:25,965 Adam: For both reasons. No, they have very dirty mouths, and they 147 00:08:25,965 --> 00:08:30,390 have venomous mouths as well. And so they're using that 148 00:08:30,390 --> 00:08:36,090 combination of bacteria and venom to help subdue their prey. 149 00:08:36,090 --> 00:08:38,850 And so they'll often eat really large things like water buffalo. 150 00:08:39,270 --> 00:08:43,590 And so they will sort of bite a water buffalo, break some blood 151 00:08:43,590 --> 00:08:47,490 vessels and introduce both the bacteria and the venom into the 152 00:08:47,490 --> 00:08:50,010 animal's bloodstream. It's getting a little bit gruesome, 153 00:08:50,130 --> 00:08:51,555 maybe too gruesome, but... 154 00:08:52,755 --> 00:08:54,195 Jane: Nothing's too gruesome for us. 155 00:08:55,695 --> 00:08:58,395 Adam: And so the animal, basically, they're anticoagulant 156 00:08:58,395 --> 00:09:01,095 compounds, so the animal, the blood doesn't coagulate, and so 157 00:09:01,095 --> 00:09:04,695 the blood just continues to flow from that wound until the animal 158 00:09:04,695 --> 00:09:07,515 then loses consciousness. And then the Komodo dragon is using 159 00:09:07,515 --> 00:09:12,555 its very long forked tongue to track where that prey animal 160 00:09:12,555 --> 00:09:15,180 went and where it died. And then they follow it to that point, 161 00:09:15,240 --> 00:09:17,160 and then they finish eating it at that point. 162 00:09:17,460 --> 00:09:21,600 Max: Hi, I'm Max, and I live in Utah, and I'm eight years old. 163 00:09:21,900 --> 00:09:25,380 And my question is, why are Komodo dragons called Komodo 164 00:09:25,380 --> 00:09:26,940 dragons, if they're not a dragon? 165 00:09:26,940 --> 00:09:31,080 Summer: Hello. My name is Summer, and I live in Portland, 166 00:09:31,080 --> 00:09:37,605 Oregon, and I'm four and a half years old, and why are Komodo 167 00:09:37,605 --> 00:09:42,045 dragons called Komodo dragons? Are they really dragon? 168 00:09:42,285 --> 00:09:45,765 Jane: The Komodo part comes from the Indonesian island of Komodo, 169 00:09:45,825 --> 00:09:50,085 where Europeans and Americans first saw these lizards. People 170 00:09:50,085 --> 00:09:53,625 who lived on the islands where these giant reptiles roam called 171 00:09:53,625 --> 00:09:57,165 them ora, meaning land crocodiles. The visiting 172 00:09:57,165 --> 00:09:59,550 scientists thought these creatures had a fearsome 173 00:09:59,550 --> 00:10:02,310 reputation. Nation, and they're really, really big, so they 174 00:10:02,310 --> 00:10:03,450 called them dragons. 175 00:10:03,870 --> 00:10:09,510 Quincy: My name is Quincy. I'm eight years old, and I live in 176 00:10:09,690 --> 00:10:17,850 Austin, Texas. How do Komodo dragons survive when they're 177 00:10:17,850 --> 00:10:18,870 endangered? 178 00:10:19,110 --> 00:10:22,110 Jane: There are a lot of factors why Komodo dragon populations 179 00:10:22,110 --> 00:10:25,575 are declining, including things like habitat loss and poaching 180 00:10:25,875 --> 00:10:29,055 and natural factors like earthquakes, volcanoes and fire. 181 00:10:29,475 --> 00:10:32,715 Climate change is another big factor that threatens their 182 00:10:32,715 --> 00:10:36,015 survival. A lot of people are working to protect Komodo 183 00:10:36,015 --> 00:10:39,255 dragons, and the largest population of these lizards are 184 00:10:39,255 --> 00:10:42,015 in the Komodo National Park where they have protected 185 00:10:42,015 --> 00:10:42,675 status. 186 00:10:42,975 --> 00:10:46,860 Ashley: My name is Ashley, and I live from Rockville, Maryland, 187 00:10:47,160 --> 00:10:52,740 and I'm four years old. How do Komodo dragons fight on two legs 188 00:10:52,920 --> 00:10:56,940 without falling off their two hind legs? 189 00:10:57,060 --> 00:10:59,400 Adam: They just have really good balance, so it gets back to that 190 00:10:59,400 --> 00:11:02,640 tail, so they'll use their tail as a counter balance, and so 191 00:11:02,640 --> 00:11:06,240 they'll have by having their tail out extended, extended 192 00:11:06,240 --> 00:11:09,645 really well, that helps keep them from from flopping over. 193 00:11:10,065 --> 00:11:15,705 Silas: My name is Silas, and I'm from Louisville, Kentucky. I'm 194 00:11:15,705 --> 00:11:21,885 seven years old, and my question is, how do Komodo Dragons get 195 00:11:22,005 --> 00:11:24,165 bacteria in their mouth? 196 00:11:24,165 --> 00:11:26,865 Adam: It's just part of the bacteria that's just sort of 197 00:11:26,865 --> 00:11:29,625 around in their environment. And so similar to the way all of us 198 00:11:29,625 --> 00:11:33,330 have bacteria in our guts, right? They pick that up from 199 00:11:33,330 --> 00:11:36,150 the environment, part of it maybe comes from their moms. 200 00:11:36,990 --> 00:11:37,710 We're not quite sure. 201 00:11:38,130 --> 00:11:41,550 Alexandra: Hi, my name is Alexandra. I live in Fort 202 00:11:41,550 --> 00:11:47,370 Collins, Colorado. My question is, how many babies do monitor 203 00:11:47,370 --> 00:11:48,810 lizards have at a time? 204 00:11:48,990 --> 00:11:51,930 Jane: Alexandra is wondering, how many babies do monitor 205 00:11:51,930 --> 00:11:53,190 lizards have at a time? 206 00:11:53,190 --> 00:11:55,635 Adam: Totally depends. Again, similar to chameleons, there's 207 00:11:55,635 --> 00:11:58,575 no one type of monitor lizard. There's dozens of different 208 00:11:58,575 --> 00:12:01,335 monitor species that range from the largest lizard on the 209 00:12:01,335 --> 00:12:04,215 planet, the Komodo dragon, to dwarf monitors, which are 210 00:12:04,215 --> 00:12:08,595 smaller than your bearded dragon. And so it depends on the 211 00:12:08,595 --> 00:12:13,095 species, anywhere from probably a couple eggs to maybe a dozen, 212 00:12:13,335 --> 00:12:14,295 something like that. 213 00:12:15,315 --> 00:12:17,775 Jane: Alright. And one more related question. 214 00:12:17,835 --> 00:12:23,640 Will: My name is Will, and I live in Atlanta, Georgia, my 215 00:12:23,640 --> 00:12:28,080 question is, if the Komodo Dragon is the biggest lizard, 216 00:12:28,260 --> 00:12:31,080 what is the smallest lizard? 217 00:12:31,560 --> 00:12:34,140 Adam: There's a number of different competitors for the 218 00:12:34,140 --> 00:12:39,796 title of smallest lizard in the world. So we talked a little bit 219 00:12:39,796 --> 00:12:40,245 earlier about these little, dwarf, mini chameleons that are, 220 00:12:40,245 --> 00:12:43,185 like, smaller than your pinky finger. So some of those are a 221 00:12:43,185 --> 00:12:46,305 good candidate. And then there's also these really tiny geckos 222 00:12:46,305 --> 00:12:50,745 called dwarf geckos, that many of which occur only on islands 223 00:12:50,745 --> 00:12:54,285 in the Caribbean. And those are also extremely tiny, where you 224 00:12:54,285 --> 00:12:58,245 could have a full size adult coil up comfortably on a dime, a 225 00:12:58,245 --> 00:12:59,205 US dime. 226 00:12:59,625 --> 00:13:02,805 Jane: So they're like, maybe your biggest fingernail size. 227 00:13:02,910 --> 00:13:05,370 Adam: Yeah, they're really, really tiny. And what's 228 00:13:05,370 --> 00:13:08,370 interesting is that most of these really tiny lizards, they 229 00:13:08,370 --> 00:13:11,070 live in leaf litter. That's their habitat. So the same for 230 00:13:11,070 --> 00:13:14,250 these tiny chameleons, they're in the leaf litter, as well as 231 00:13:14,250 --> 00:13:16,590 these little, tiny geckos on Caribbean islands, they're 232 00:13:16,950 --> 00:13:18,870 they're hanging around in the leaves, fallen leaves on the 233 00:13:18,870 --> 00:13:19,170 ground. 234 00:13:19,170 --> 00:13:23,190 Jane: That would be so cute to see. How about iguanas? 235 00:13:23,250 --> 00:13:28,575 Hudson: I'm Hudson, and I am five years old, and I live in 236 00:13:28,575 --> 00:13:37,515 Arvada, Colorado, and what my question is is, why are iguanas 237 00:13:37,635 --> 00:13:43,395 or lizards green most of their time? 238 00:13:43,755 --> 00:13:46,455 Adam: Mostly it's a camouflage thing. So iguanas, green 239 00:13:46,455 --> 00:13:49,860 iguanas, specifically, they're arboreal, which means they spend 240 00:13:49,860 --> 00:13:53,160 most of their lives up in trees, and so their green color helps 241 00:13:53,160 --> 00:13:55,800 them to camouflage among the leafy branches where they live. 242 00:13:55,920 --> 00:13:58,920 Jane: Interestingly, Hudson green iguanas aren't always 243 00:13:58,920 --> 00:14:02,100 green. When I was in Florida doing some But Why reporting 244 00:14:02,100 --> 00:14:05,700 about invasive species a few years ago, I saw a lot of big 245 00:14:05,760 --> 00:14:10,500 green iguanas that were actually orange. Mature males often turn 246 00:14:10,500 --> 00:14:13,140 orange during the breeding season from about December 247 00:14:13,185 --> 00:14:13,965 through April. 248 00:14:14,025 --> 00:14:20,685 Roshan: Hi, my name is Roshan and I'm five years old, and I 249 00:14:20,685 --> 00:14:24,165 want to know, why do iguana have spiky things on their back? 250 00:14:24,645 --> 00:14:28,185 Adam: That's a great question. So male green iguanas, in 251 00:14:28,185 --> 00:14:31,905 particular, they're using those spikes as a way to show off to 252 00:14:31,905 --> 00:14:37,305 females how healthy and vigorous they are. And then it's a little 253 00:14:37,305 --> 00:14:40,650 bit of a defensive thing, where those those scales can sort of 254 00:14:40,650 --> 00:14:44,250 protect against predators, but it's mostly for sort of showing 255 00:14:44,250 --> 00:14:45,270 off to the females. 256 00:14:45,510 --> 00:14:49,410 Wyatt: My name is Wyatt, and I am five years old. I live in Los 257 00:14:49,410 --> 00:14:54,930 Angeles, California. My question is, why do male iguanas have 258 00:14:54,930 --> 00:14:56,130 dewlaps? 259 00:14:56,130 --> 00:14:58,830 Jane: Wyatt has obviously learned a little bit about 260 00:14:58,875 --> 00:15:01,455 iguanas for people who don't. Know what a dewlap is. Can you 261 00:15:01,455 --> 00:15:02,115 tell us that too? 262 00:15:02,115 --> 00:15:05,775 Adam: Yeah. So a dewlap is this sort of thin, flexible flap of 263 00:15:05,775 --> 00:15:10,335 skin that hangs down from the throat of iguanas. They can't 264 00:15:10,335 --> 00:15:13,335 really control it. It just sort of lays there. There are other 265 00:15:13,335 --> 00:15:16,215 lizards called anoles, which some of you may have heard of, 266 00:15:16,455 --> 00:15:19,695 and they can actually push their dewlap out or retract it flat 267 00:15:19,695 --> 00:15:23,280 against their throat. In the case of the anoles, the dewlap 268 00:15:23,280 --> 00:15:27,300 is often very brightly colored, and so it's mostly male anoles 269 00:15:27,300 --> 00:15:30,600 that have these colored dewlaps, or flaps of skin under their 270 00:15:30,600 --> 00:15:33,720 throat, and they're using them to signal to other males for 271 00:15:33,720 --> 00:15:37,500 territorial interactions and also to signal to females, hey, 272 00:15:37,500 --> 00:15:39,960 I'm over here. I'm very vigorous. I might be a good 273 00:15:39,960 --> 00:15:43,740 mate. For iguanas, they're more it's just a thing that males 274 00:15:43,740 --> 00:15:46,605 have again, to sort of signal their vigor. So bigger adult 275 00:15:46,605 --> 00:15:49,605 male iguanas have bigger dewlaps, and they might make 276 00:15:49,605 --> 00:15:52,665 better mates in minds of the female iguanas. 277 00:15:52,725 --> 00:15:56,505 Joseph: Hi. My name is Joseph. I'm six years old. I live in 278 00:15:57,165 --> 00:16:05,205 Maryland. I'm wondering how some gliding reptiles like the Draco 279 00:16:05,205 --> 00:16:09,630 lizard, glide halfway through the air and catch themselves on 280 00:16:09,630 --> 00:16:10,230 trees. 281 00:16:10,230 --> 00:16:13,650 Adam: This is one of my favorite groups of lizards. So if you're 282 00:16:13,650 --> 00:16:15,930 listening right now, what you can do is you can if you hug 283 00:16:15,930 --> 00:16:18,570 yourself, not sort of on your shoulders, but sort of around 284 00:16:18,570 --> 00:16:21,330 your stomach, where your hands are positioned, they're 285 00:16:21,330 --> 00:16:24,510 positioned over your rib cage. You can sort of feel your ribs 286 00:16:24,510 --> 00:16:28,650 if you press into your body. So the Draco lizards, the wings 287 00:16:28,650 --> 00:16:31,290 that they have are basically their modified ribs. Their 288 00:16:31,335 --> 00:16:34,695 modified rib cage. So now, if you take your arms and you keep 289 00:16:34,695 --> 00:16:38,295 your elbows pressed tightly against your sides and you flare 290 00:16:38,295 --> 00:16:41,475 your arms out, you can imagine that your arms are sort of your 291 00:16:41,475 --> 00:16:44,655 ribs, and that's what Draco lizards do. They can take their 292 00:16:44,655 --> 00:16:47,895 ribs from being sort of flat against their bodies, and they 293 00:16:47,895 --> 00:16:52,155 can flare them out to create these wings, effectively wings, 294 00:16:52,935 --> 00:16:56,160 and they use those wings to then glide from tree to tree in the 295 00:16:56,160 --> 00:16:57,120 forest where they live. 296 00:16:57,660 --> 00:17:00,300 Jane: How do they catch themselves on the tree without 297 00:17:00,300 --> 00:17:01,380 smashing into it? 298 00:17:01,800 --> 00:17:06,060 Adam: So they'll sort of break, they'll sort of flare their 299 00:17:06,060 --> 00:17:09,660 wings up and catch the air and slow down right before impact. 300 00:17:10,260 --> 00:17:13,020 But because they're so light, these are not large lizards. You 301 00:17:13,020 --> 00:17:15,780 know, they're about the size of Fence lizards. For those of you 302 00:17:15,780 --> 00:17:16,495 who might grow up, might have grown up with those, they're 303 00:17:16,495 --> 00:17:19,965 much smaller than a bearded dragon. They're sort of like 304 00:17:20,145 --> 00:17:22,785 half the size of a leopard gecko, typically, and they're 305 00:17:22,785 --> 00:17:25,605 very, sort of slender, so they're not super heavy, so they 306 00:17:25,605 --> 00:17:29,025 don't have a big impact when they hit a tree after flying 307 00:17:29,025 --> 00:17:32,565 from another tree, and so they're not creating a lot of 308 00:17:32,565 --> 00:17:35,025 force. And so they can just sort of plop onto the side of the 309 00:17:35,025 --> 00:17:37,245 tree and grab on with their claws, and they're good to go. 310 00:17:37,785 --> 00:17:39,098 Jane: All right, one other type of lizard that we have a 311 00:17:39,098 --> 00:17:42,210 question or type of animal that we have a question about: 312 00:17:42,270 --> 00:17:47,370 Nikki: Hi, my name is Nikki, and I'm nine years old. I'm from 313 00:17:47,550 --> 00:17:51,210 Israel. Why is tuatara not a lizard? 314 00:17:51,750 --> 00:17:55,350 Adam: This is another really good question. And so without 315 00:17:55,350 --> 00:17:57,570 getting too much into the details, it's because they have 316 00:17:57,570 --> 00:18:01,290 a bunch of different structures in their skeleton that no 317 00:18:01,290 --> 00:18:06,915 lizards have. And so tuataras branched off on the tree of life 318 00:18:07,035 --> 00:18:11,115 before, earlier than any other lizard. And so they're what we 319 00:18:11,115 --> 00:18:14,415 call sister to all other lizards. So a good way to think 320 00:18:14,415 --> 00:18:18,315 about is that all true lizards are more closely related to each 321 00:18:18,315 --> 00:18:21,795 other than any of them is to the tuatara. The tuatara is sort of 322 00:18:21,795 --> 00:18:25,575 this weird offshoot in the tree of life, the reptile tree of 323 00:18:25,575 --> 00:18:28,380 life. And even though they look externally a lot like a lizard, 324 00:18:28,620 --> 00:18:31,500 there's a number of different features of their ribs, of their 325 00:18:31,500 --> 00:18:35,400 skull, of their teeth that no lizards have. And so they're 326 00:18:35,400 --> 00:18:36,420 very special in that way. 327 00:18:36,420 --> 00:18:37,500 Jane: What do they look like? 328 00:18:37,500 --> 00:18:41,400 Adam: They look kind of like iguana, like a brown iguana. 329 00:18:41,640 --> 00:18:44,340 They don't grow quite as big as green iguanas, and their tail 330 00:18:44,340 --> 00:18:48,060 isn't as long, but they're sort of spiky. They have a crest 331 00:18:48,120 --> 00:18:52,005 along their back. To all intents and purposes, they sort of just 332 00:18:52,005 --> 00:18:54,525 look like a big lizard, but they are not lizards. 333 00:18:54,525 --> 00:18:58,125 Jane: Is there anything else that you think kids should know 334 00:18:58,125 --> 00:19:01,965 about lizards? A lot of us are very interested in them. But you 335 00:19:01,965 --> 00:19:05,205 know what's something that you could send us off with as 336 00:19:05,325 --> 00:19:08,505 something else to think about or investigate on our own about 337 00:19:08,505 --> 00:19:09,105 lizards? 338 00:19:09,525 --> 00:19:12,225 Adam: Yeah, so one of the things that I'm really interested in, 339 00:19:12,225 --> 00:19:14,910 and is really important to me, is making sure that we're trying 340 00:19:14,910 --> 00:19:18,390 to do our best to keep lizards around. A lot of lizards are in 341 00:19:18,390 --> 00:19:21,270 trouble all across the world, and Southern California is no 342 00:19:21,270 --> 00:19:24,090 different, and one of the biggest things that anybody can 343 00:19:24,090 --> 00:19:28,410 do to help protect lizards is to not use pesticides in your 344 00:19:28,410 --> 00:19:33,510 gardens. So pesticides typically kill insects, and most lizards 345 00:19:33,510 --> 00:19:36,255 feed on insects, and so if you're killing off all the 346 00:19:36,255 --> 00:19:39,375 insects, the lizards have nothing to eat and they 347 00:19:39,375 --> 00:19:43,815 disappear. So by not using pesticides, you will help out 348 00:19:43,815 --> 00:19:46,575 your local lizards, and I think we all stand to benefit from 349 00:19:46,575 --> 00:19:46,755 that. 350 00:19:47,235 --> 00:19:50,475 Jane: That's a great place to end it. Thanks so much to Adam 351 00:19:50,475 --> 00:19:53,715 Clause, collections manager of herpetology at the San Diego 352 00:19:53,715 --> 00:19:57,435 Natural History Museum. We loved going to see the reptile and 353 00:19:57,435 --> 00:20:01,080 amphibian specimens in the museum's collection. As you 354 00:20:01,080 --> 00:20:04,620 know, you can ask us a question on just about anything. 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