Tuatara: Little Dragons

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Speaker 1: Hi, I'm Ebony Money and I'm Rick Schwartz. Welcome to Amazing Wildlife, where we explore unique stories of wildlife from around the world and uncover fascinating animal facts. This podcast is a production of My Heart Radio and San Diego Zoo Wildlife Reliance in international nonprofit conservation organization buying the San Diego Zoo and Safari Park. This next animal is truly one of a kind. It's found only in New Zealand and it holds the title of the island's largest reptile. It's the two atara. The tuataras closest relatives, are an extinct group of reptiles that date back to a time when dinosaurs first roamed the earth. That's why some people call two ataras living fossils. In the world of science, they are considered among the most unique wildlife in the entire world. Rick, I hadn't heard of the tuatara, but when I pulled up a picture, I thought, oh, it's a lizard. The tuatara. It looks like a large lizard. More specifically, it looks like an iguana, similar to the iguanas we've highlighted and past conversations. But one of the first things I read was that the tuatara is not a lizard. So Rick, what makes a lizard and why is the tuatara not considered a lizard? Well, okay, have any We're about to leap into one of the more fascinating reptiles that I have ever had the pleasure of meeting or learning about. And yes, although the tuatara looks very much like a lizard, I mean, it walks on all fours, it has a tail. It even has a crest of spiky scales called spines down the center of its back to its tail. Some people even say they remind them of lizards in the iguana family just by the way they look. But when we take a closer look at the taxonomy or the details of bone structure and other anatomical structures, it becomes apparent that the species does not fit into the other lizards scientific families. In fact, it is unique enough that the tuatara is in a completely different scientific order known as ryan co Cephilia. This scientific order of reptiles once had over twenty different species living during the Mesozoic era. This makes the tuatara the last species of a prehistoric reptile that thrived in the age of dinosaurs. And to answer your question, Ebony about what sets them apart from lizards. Well, some of the less obvious but possibly most telling reasons the tuatara is not a lizard are internal There are several bones structures that the tuatara has that are not shared with other lizards, and without going into too much detail, it also has to do with the way the tuatara's teeth are connected to the jaw and when we look at some of their behaviors, while we also can see how different they are from other lizards. For example, tuataras actually enjoy cooler weather while most lizard species like it warm and unlike lizards, to autaras are nocturnal and a physical feature that we can see act lee now that I think about it, tuataras have no external ear canals like lizards do. Well. Rick So, when an animal's existence is traced back to prehistoric times the age of dinosaurs, does it actually mean that the tuatara may have lived among the dinosaurs or does that mean that the reptile evolved from an animal that was actually living among the dinosaurs. Well, that's a really good way to look at ebony, and sometimes it does mean that a species alive today evolved from an ancestor that lived during the dinosaur time. But in the case of the tuatara, they are indeed the only surviving member of a distinctive reptilian order that lived alongside the dinosaurs. Wow, the tuataras ancient lineage is just one of the things that makes the reptile unique. There's also the fact that the tatara is born with a third eye. Rick, this sounds supernatural. What can you tell us about their eye? I know, Ebony right, it does sound a little supernatural at first, maybe even a little creepy for some people. But believe it or not, there are other species with this third eye, also known as a parietal eye. Other species that have this include some sharks, lamp rays, even real true lizards, frogs, and salamanders. Now, in the case of the tuatara, it is only visible in the hatchlings for the first few months of life, then in time it is covered with a scale and pigments. But get this, the third eye does have an actual retina, lens and nerve endings, yet it is not used for seeing like a traditional eye. So we know this I is sensitive to light and may even help the tuatara judge the time of day, and it is probably important to their body circadian rhythm and seasonal cycles. That's amazing. We've established that the tuatara is found only in New Zealand. The island is known for being mountainous with cities and forests where my someone's spot one of these third eyed reptiles hold on ebony. I don't want people to think there are three eyed lizard like reptiles roaming around. And remember the third eye is covered after a few months of age, so they still look a lot like the two eyed reptiles that were accustomed to seeing. Well, that's got exactly right. I just want to make sure we're clear on that now. As far as the location, yes, you're right. The tuatara is only found in New Zealand and more specifically on the islands off the northern coast of North Island and some islands in the Marlborough Sounds. They inhabit coastal forest and clearings using sort of burrows for shelter, and they can dig their own burrows, but they will also take advantage of abandoned burrows from other animals like seabirds that also nest in burrows that live in reside on those islands as well. Oh and get this, some studies have shown that the tuatara will move into a burrow that is in use by a bird, but the bird will allow the tutor to do this. This then gives a tutor the benefit of using the warmth of the bird, sometimes referred to as being a heat thief. So what do the two autaras eat? For the most part, they consume invertebrates or insects. Beetles are high on the list of most consumed foods, but millipedes, spiders, and worms are also on their menu. They have been known to eat lizards, birds, and bird eggs at times too, but because their preferred food is active at night, adult tuataras are active at that time as well. Now get this, Young tuataras are usually hunting for their food during the day to keep away from the adults because adult tuataras will try to eat them. So that sounds like a smart move exactly. So rats are considered the most serious threat to the survival of the two atara. How have rats impacted tatara populations? Yeah? Unfortunately, I mean it is true. Rats are a big problem for the tuataras, because rats can easily stow away on boats, allowing them to reach these islands that would otherwise be left undisturbed without rat populations at all and on. Fortunately, the rats are very good at finding tuatara nests and eating the eggs. In fact, they will also prey upon the young tuataras as well. This kind of introduced predation that significantly impacts the ability for tuataras to create and maintain healthy new generations, and of course this then leads to population declims. Just ahead, we'll have more interesting facts about this one of a kind reptile. But first this now it's time for the San Diego Zoom Minute, an opportunity for you to learn what's new at the Zoo. A new study has found contaminants that were banned decades ago are still impacting critically endangered California condors. The research, led by San Diego State University and San Diego Zoo Wildlife Alliance scientists in collaboration with other partners, found the condors maybe at increased risk for reproductive impairment because they consume dead marine mammals along the California coast. California condors were nearly extinct a few decades ago, and their population has been slowly recovering thanks to extensive breeding and reintroduction efforts. The research highlights the value of Baja California, Mexico has a reintroduction site for the condors. Did you know the name to a tara comes from the Maori word for peaks on the back. Two a taras have spiny crest along their backs, made from soft, triangular folds of skin. These spines are more prominent in males, who can raise them during territorial or courtship displays. We're talking about the two atara, also referred to as a living dinosaur. Kim Gray is the curator of herpetology and ichpeology with the San Diego Zoo Wildlife Alliance. She's here now to tell us more about this unique animal. Welcome Kim, Hi, Nice see you. Nice to see you as well. Can you talk to us about your experience working with the tuatara? Sure? Well, I've actually had the pleasure of working for our organization for almost twenty five years now and we've had them this entire time. So when I first joined our organization, they were just little bitty guys. We had got them in as part of an assurance population planning program to see if we could learn as much as we can about how to rear them in managed habitat which could help influence and make decisions for the wild populations, and how we might be able to help contribute to saving them in the wild. So I've had the opportunity to watch them grow up. So they were about four years old when I joined, so they're about thirty years old now, and they only become sexually mature around fifteen years of age. So we'll get into more of that, but it's nice to be able to watch them grow up. So is there anything in particular about the tuatara that makes caring for them so unique? Well, I have to tell you. So when we first see them, we actually try to think about did we need to actually reverse day and night to match that in New Zealand because obviously we're on the other side of the planet and so we have reverse night cycles. But we did some more research and we decided that wasn't necessary and our climate in certain areas can be pretty similar. But we wanted to make sure that we know that reptiles in particular likely to at our need a lot of UV light for strong bones, and so in the area that we have them in the building that we have them in, we actually designed a roof that moves, so it's a little bit like a garage door. It opens up to allow natural light and night, natural air temperatures and sunlight to come in. So those are some unique ways that we tried to meet the needs of the animals to allow them to have natural UV lighting with this unique roof system. So what was the answer, did you have to reverse day and night? No, And that was part of it because we wanted to be able to retract the roof to allow natural sunlight. Obviously that wouldn't be possible, so we learned pretty quick that that wouldn't be necessary. And since we got them at such a young age, they adapted to our cycles. But it would be definitely something to think about if we ever were going to rewild these animals and put them back, we'd have to almost give them an opportunity, just like we deal with jet leg to give them a little bit of a photo period change to be matching that in New Zealand. And how about mating. The tuatara are said to have really long incubation periods. Males can reproduce every year, but females generally breed every two to five years. How does this impact the population size? Sure, that's a great question because for conservationists you have to be planning so far in the future. For example, like we've had them at our organization for thirty years, had the privilege of working with them. They don't become sexually mature until they're about fifteen years of age. That's a long time when you're thinking of conservation efforts. So this species, we don't know a lot about them, but we know they've been around a long time. We know they prefer cooler temperatures, and so their metabolism is slow, their sort of life cycle is slow. They don't become sexually mature until their fifteen There's a lot that we're still learning about them, but males and females, we believe we start seeing mating behaviors starting around that late teenage years there. In speaking of mating, the male to atara works very hard for an opportunity to mate. A male can fan out his spine to attract a female and it kind of puts me in the mind of a peacock. But then I wonder, because I'm always rooting for the underdog, what happens if a male to a tara is unsuccessful at attracting a mate. That's a really good question, I think. Obviously they're long lived, so maybe hopefully they'll have a second chance in the following years to come. It's kind of unique. So their spines, their crest on their back is not sharp, their skin is actually very soft. It feels almost like more like a toadskin. And what they're able to do is they inflate, so when they see another male, they puff themselves up, and that crest on their backs stands up to make themselves look bigger, and they puff out their throats and they do a little head bob dance. And then that's actually attractive to the females as well. So it serves two purposes. One it's to make them more attractive to the females, and the other is to deter other males. Usually it's the bigger, stronger, better dancers, so to speak, that get the girls. So maybe they just need more years of practice. Yes, and you mentioned tuataras have been documented to live up to a hundred years. Yeah, we're not even sure there's a couple of estimates of one male that might have been about a hundred and forty five years old, but nobody kept records really clearly back then, and we didn't have pit tags and the techniques with genetics, like, we didn't have any of that back then, so we were estimating could be up to a hundred and fifty years old. So when a reptile can survive a hundred plus years is there any working theories out there as to why, Yeah, very good question. It's kind of stumps me as well. The only thing we can kind of contribute some of these factors too. Again we talked about is like typically a mammal would hibernate. We call it broomation in reptiles and amphibians, So they take the winter months off, so they're resting, they're not exerting a lot of energy, their systems kind of shut down, so it's almost like they're in refrigeration mode, right, And we have seen that in some other species that live in the Arctic, just in those really cold temperatures, you're almost like living in a refrigerator and slowing yourselves and your metabolism down. I believe some whale species can live to be like two three years old, and we had no idea that that was even possible. I think there might be something to do with just taking a few months off. We need longer vacations as humans will live longer. I vote for that. Like some lizards, a tuatara can regrow a lost hell. Are there any theories about why some reptiles have the capabilit city of regeneration while other animals, like us humans can't. Sure. That's another great question and it's fascinating to me because if you think about it, the tutor is a very ancient species, so it's been around longer, and we do blump it in with lizard species even though it's a little bit different, and that tells us that this ability to lose the tail and regrow it is very ancient, and so lizard species that are more modern, not all of them have that ability. So for example, uh prehensile tailed skink the name it uses its tail like a monkey. It doesn't lose its tail. It's lost that ability. So what we understand is this trait has probably been around a millennia to help deter predators so when they're really scared or predators attacking them, their tail tip will sort of like automatically detach and it keeps wiggling. So the idea is that the predators after this quick, easy meal, it distracts it from the main body and then the twoutar can regrow it and it we grow the bones within the tail. It's more like a cartilage material, but it still is able to regrow its tail, and then it can do that a number of times. Yeah, pretty amazing. So the tuatara is endemic to New Zealand, so there's not any in our backyard. But is there anything that people can do to better co exists with the tuatara and other reptiles and just be better neighbors? Sure well, certainly supporting us in our colleagues and even in within New Zealand they have breeding populations there, So the Auckland Zoo for example, does a lot of amazing work with them. But I think it's just being more aware of our footprint and when we travel if you get the chance to go their support conservation initiatives and visiting islands that might have them there, and supporting local conservation local communities that support their work. But even to just being aware like where we travel in the world, we bring pests and parasites in those in basive species we inadvertently do it, but thes and the cats and the things like that do take a toll on native wildlife. So just being aware of that, I think it's very helpful. And speaking of traveling, is it actor that they're kind of like culturally revered where they're from in New Zealand, right, So it's hard to put a term on that, but it's basically their ancestral heritage and so um, it's really strong family ties and really revere, like you said, just respect that species. It's like a totem species. It's like their ancestors. So they have a great deal of respect for this species and the land that it lived on and still does historically. So yeah, it's just it boils down to being respectful of the species as they are looked at like a family member. So more mythologically, I've heard the tutara being compared to a mini dragon. Having worked with them, can you understand where that comparison has kind of come up over the years, certainly, and especially just how danis or like they are their little fee and as I mentioned, their skin feels like a toad. It's a different kind of scalation than with your other typical reptiles. And their eyes are just really everything about them is unique, but especially their teeth. So their teeth aren't similar to reptiles in shape, however, they're part of their actual bone of their jaw, and they're just everything about them is ancient looking. Yeah, you can imagine when you get a chance to look at one, it just it looks like how you would imagine a dragon or a dinosaur. Yeah, awesome. So, as we've mentioned that Tuatara is endemic native to New Zealand, what has it been like for you to have an opportunity to work with so many different species from all over the world. It's been wonderful and I have to say it makes the world feel much smaller getting the chance to meet colleagues who become your friends doing conservation work, and even though it's so very far away, it feels a lot closer and just makes it feel like we're part of a global community and we are all making a difference. And even if you never get the chance to go to New Zealand, just by visiting us at the San Diego Zoo, you're making an impact in helping this global community of conservationists doing what we can to save wildlife. It's pretty amazing. We've been talking with Kim Gray, curator of herpetology and ichnology with the San Diego Zoo Wildlife Alliance. Thank you, thank you, thanks for listening. We hope you learned a lot about New Zealand's largest reptile, the two Tara. Be sure to subscribe and tune into next week's episode, in which we bring to the story of a critically endangered frog species that prefers mountain streams over anything else. I'm Abymone and I'm Rich Schwartz. Thanks for listening. If you would like to find out more about San Diego Zoo Wildlife Alliance, please visit sdz w A dot org. A me Seeing Wildlife is a production of I Heart Radio. Our producer is Nikia Swinton and our executive producer is Marcy to Peanut. Our audio engineer and editor is Sierra Spreen. For more shows from My Heart Radio, check out the I Heart Radio app, Apple podcast, or wherever you listen to your favorite shows.