Episode 402: The Hoop Snake and Friends

Thanks to Nora and Richard from NC this week as we learn about some scary-sounding reptiles, including the hoop snake!

Further reading:

The Story of How the Giant “Terror Skink” Was Presumed Extinct, Then Rediscovered

San Diego’s Rattlesnakes and What To Do When They’re on Your Property

Snake that cartwheels away from predators described for the first time

Giant new snake species identified in the Amazon

The terror skink, AKA Bocourt’s terrific skink [photo by DECOURT Théo – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=116258516]:

The hoop snake according to folklore:

The sidewinder rattlesnake [photo taken from this article]:

The dwarf reed snake [photo by Evan Quah, from page linked above]:

The green anaconda [photo by MKAMPIS – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=62039578]:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

As monster month continues, we’re going to look at some weird and kind of scary, or at least scary-sounding, snakes and lizards. Thanks to Nora and Richard from NC for their suggestions this week!

We’ll start with the terror skink, whose name should inspire terror, but it’s also called Bocourt’s terrific skink, which is a name that should inspire joy. Which is it, terror or joy? I suppose it depends on your mood and how you feel about lizards in general. All skinks are lizards but not all lizards are skinks, by the way.

The terror or possibly terrific skink lives on two tiny islets, which are miniature islands. These islets are themselves off the coast of an island called the Isle of Pines, but in French, which I cannot pronounce. The Isle of Pines is only 8 miles wide and 9 miles long, or 13 by 15 km, and is itself off the coast of the bigger island of New Caledonia. All these islands lie east of Australia. Technically the islets where the skink lives are off the coast of another islet that is itself off the coast of the Isle of Pines, which is off the coast of New Caledonia, but where exactly it lives is kept a secret by the scientists studying it.

The skink was described in 1876 but only known from a single specimen captured on New Caledonia around 1870, and after that it wasn’t seen again and was presumed extinct. Colonists and explorers brought rats and other invasive animals to the New Caledonian islands, which together with habitat loss have caused many other native species to go extinct.

But in December 2003, a scientific expedition studying sea snakes around the New Caledonian islands caught a big lizard no one recognized. Once the expedition members realized it was a terror skink, alive and well, they took lots of pictures and videos of it and then released it back into the wild. Since then, more specimens have been discovered during four different expeditions, but only on the islets, not on any of the bigger islands. It’s so critically endangered that its location has to be kept secret, because if someone captures some of the lizards to sell on the illegal pet market, the species could easily be driven to extinction.

The terror skink is gray-brown with darker stripes, a long tail, and a slightly downturned mouth that makes it look grumpy. It grows about 20 inches long, or 50 cm, including its tail. This is really big for a skink, so technically it’s a giant skink.

It gets the name terror skink from its size and from its teeth, which are large and curved like fangs. It mainly eats one particular species of land crab, which is why its jaws are so strong and its teeth are so sharp, so it can bite through the crab’s exoskeleton.

Another lizard with a spooky name that has been presumed extinct is the gray ghost lizard, suggested by Richard from NC. It’s more properly called the giant Tongan ground skink, and it’s native to some more South Pacific islands—specifically, the Tongan Islands. These islands are even farther east from Australia than the New Caledonian islands, and are actually closer to New Zealand than to Australia, although they’re not really very close to either.

The giant Tongan ground skink was described in 1839 from two specimens collected in the late 1820s on Tongatapu Island. They’re the only two specimens known and the lizard is considered extinct, especially considering that these days, the island is almost completed deforested and rats, dogs, and cats have been introduced to it, which has driven many species to extinction.

But after the terror skink was rediscovered, scientists started to wonder if the gray ghost might still be around. It was called the gray ghost because it was so hard to see, since it was dark gray in color. The native Tongan people considered it a good omen if someone saw one, since it was so rare.

A paper published in early 2024 suggests that the gray ghost might be living on some smaller islands where forests still remain, and also suggested that it might be nocturnal and a burrowing skink. That would explain why it was so rarely seen by the people who lived on its island when it was still alive.

We know basically nothing about the gray ghost. Hopefully an expedition to the smaller Tongan islands will rediscover it so we can learn more about it and protect it.

Richard from NC also suggested we talk about the hoop snake, an animal of folklore. I remember reading about it as a kid in a book about American folklore animals, most of which were clearly jokey and not meant to seem real. The hoop snake sounded more realistic.

The hoop snake was supposed to be a long, slender snake that slithered around normally most of the time, but when it needed to move faster, it would grab the end of its tail in its mouth and roll like a wheel, or a hoop. Some versions of the story had the snake rolling along with the tip of its tail pointed forward, and since the tail was supposed to be sharp and venomous, it would roll after you so fast that when its tail stabbed you, you’d drop dead. The only way to escape would be to jump behind a tree. The tail would stab the tree instead and you could run away while the hoop snake was trying to unstick its tail. The venom in its tail was supposed to be so deadly that the tree would turn black and die. Other versions of the story said you had to jump through the snake’s hoop to confuse it, which would allow you to get away safely.

All this is weird, to say the least, but some snakes do have ways of traveling that are unusual. The sidewinder, for instance, is a real species of rattlesnake from the southwestern United States and northwestern Mexico. It grows around 2 ½ feet long, or 80 cm, and has pointy scales, called keeled scales, including a pair above its eyes that make it look like it has little horns. Since it’s a type of rattlesnake, it has a rattle that it can shake to make a loud warning noise. It’s mostly brown in color, or sometimes pinkish, yellowish, or even whitish, with darker stripes or blotches down its back. Its coloration helps camouflage it against the ground, and it will actually change color slightly depending on the temperature. This is something other rattlesnakes can do too.

The sidewinder lives in desert conditions where it has to travel through loose sand, and the sand is also extremely hot. While the snake can travel normally when it wants to, it sidewinds to move quickly over loose sand or very hot sand that might burn it. It lifts most of its body up so that it’s only touching the ground in two places, then undulates its body so that the sections touching the ground constantly move. That way no part of its body has to stay in contact with hot sand for more than a split second. It travels in a path that runs diagonal to the direction its body is pointing. That sounds complicated, but it’s easy for the snake. It’s not even the only snake that can travel by sidewinding. Other desert-living snakes travel across hot sand by sidewinding, including several species from Africa, but just about any snake can do it if they need to. It allows a snake to travel over surfaces that are too slippery for its belly scales to get a grip.

The story of the hoop snake might be based on garbled reports of sidewinders, but it might just be a completely invented animal. The hoop snake story is found in other parts of the world too, especially Australia, although it dates back to at least the late 18th century in the United States.

No snake in the world has the anatomy to allow it to roll like a hoop without hurting itself. But there is one other snake that does something very similar, called cartwheeling. It’s the dwarf reed snake that lives in Malaysia and other parts of southeast Asia. Reed snakes aren’t very well known to science, so this cartwheeling activity wasn’t documented scientifically until recently, with the study published in 2023. Reed snakes are nocturnal and spend most of the daytime hiding under rocks or logs, or buried in dead leaves or sand, so they’re not seen very often by people. The dwarf reed snake is slender and only grows about 10 inches long, or 25 cm.

Some small snakes can jump short distances by pushing their tails against the ground. The dwarf reed snake does something similar, but more complicated. It pushes off with its tail, with its body curved in a sort of S shape. It lands on its head and rolls over completely, head to tail, and then pushes off the ground again with its tail. It can move extremely fast in this way to get away from predators, but it takes a whole lot of energy. But when it’s moving downhill, with gravity on its side, it can continue to cartwheel longer.

Cartwheeling isn’t something the snake does often, and it’s rare that a human would ever observe it. But just like sidewinding, some scientists think cartwheeling might be a motion that more snakes can do if they really need to. Maybe that’s where the hoop snake legend started.

Let’s finish with a suggestion from Nora, who wanted to learn more about the green anaconda. That’s a scary snake for sure, because it happens to be the biggest snake alive today, and almost the longest, as far as we know.

The green anaconda lives throughout much of South America, although not in Patagonia because like most reptiles, it needs warm weather to function. It’s a beautiful olive green with black blotches, and it’s a big, bulky snake. It spends a lot of time in the water, which helps it stay cool in hot weather and helps support its weight comfortably, and its eyes are near the top of its head so it can watch for prey while it’s mostly submerged.

The anaconda is a member of the boa family and is a constrictor. It’s not venomous, but you really don’t want a hug from a hungry anaconda. Its body is bulky because it’s incredibly strong, and once it starts to contract its muscles, whatever it’s constricting has only minutes left to live. It can kill animals as large as caimans, which are a type of crocodile, tapirs, capybaras, deer, and even jaguars. For the most part, though, an anaconda doesn’t want to bother with prey that could potentially hurt it, so it will stick with smaller animals that are still big enough to make it worth the effort. And yes, it is possible that an anaconda in the wild could kill and eat a human, but there’s no reliable evidence that it’s ever happened.

It’s hard to know exactly how long and how heavy an anaconda can get. There are lots of stories of 30-foot, or 9-meter snakes, but that seems to be a wild exaggeration. Snakes are stretchy, and a healthy live snake doesn’t really want to stretch out straight to be measured. A dead snake is even stretchier than a live snake. A shed snakeskin is the stretchiest of all, and usually has stretched out quite a bit when the snake was shedding. A good estimate is that a big female anaconda can grow about 20 feet long, or 6 meters, and can weigh around 250 lbs, or 114 kg. Males are smaller on average, and a wild snake will weigh less than one kept in captivity.

There are definitely larger individual anacondas, especially considering that reptiles continue to grow throughout their lives, but they’re probably not that much longer. This is only a little shorter than the reticulated python, which can definitely grow up to 23 feet long, or 7 meters.

One important detail about the size of the green anaconda is that the biggest snakes live in the Amazon rainforest–but the Amazon rainforest is really hard for humans to navigate safely and most anacondas killed or kept in captivity lived in other parts of South America. So there might easily be anacondas in the rainforest that are much bigger than the ones scientists have been able to measure so far.

In February of 2024, a journal article was published about a 2022 National Geographic nature documentary and scientific expedition to the Amazon basin to find a rumored population of extra-large anacondas. The expedition was led by hunters from the Waorani people, who consider the snakes sacred, and the hunters and their chief were credited as co-authors of the paper, as they should be since they provided so much information.

The scientists were able to examine several fully grown anacondas and take tiny tissue and blood samples to test later. They were astounded at the size of the snakes they found, including one that measured 20 and a half feet long, or 6.3 meters. The hunters reported seeing snakes that they estimated as over 24 feet long, or 7.5 meters, that might have weighed as much as 500 pounds, or 226 kg.

Beyond mere size, though, is something very interesting, which the scientists learned when they got home and ran genetic tests. The anacondas are actually quite different genetically from other anacondas known to science, that live farther south. They described the snake as a new species, which they refer to as the northern green anaconda, but it has actually resulted in a lot of controversy. Some scientists agree that the northern green anaconda is a separate species, others think it’s only a subspecies of the green anaconda, while others think the genetic differences are minor and separating the northern green anaconda from other anacondas isn’t justified by the evidence.

Obviously scientists need to follow up and learn more about the anacondas, but one thing is clear. There are some really, really big snakes out there in the Amazon.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 097: Unusual Reptiles

Thanks to listeners Finn and Leo, who suggested this week’s topics of strange lizards, and the thorny devil and mata mata turtle, respectively! Join us this week to learn about those reptiles and a bunch more!

Thorny devil. Definitely do not eat.

The mata mata turtle. Big leafhead boi

A frilled lizard BWAAAAAMP

A Pinocchio lizard. Wonder where that name comes from.

Poke poke poke does this bother you? poke poke

om nom nom

A shingleback, or as I like to call it, an ambulatory poop:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

We have more listener suggestions this week! Ages ago, listener Finn suggested strange lizards, and more recently, listener Leo suggested a particular type of strange lizard and a strange turtle.

We’ll start with Leo’s suggestion, the thorny devil. He describes it as “a cool animal with spikes all around it,” which is definitely a good way to put it. The thorny devil is a lizard from Australia, and it does indeed have spikes all over its head, back, and tail, and smaller spikes on its legs. The spikes are modified scales and are sharp.

The thorny devil grows to around 8 inches long, or 20 cm, with females being larger than males on average. In warm weather its blotchy brown and yellow coloring is paler than in colder weather, when it turns darker. It can also turn orangey, reddish, or gray to blend in to the background soil. Its color changes slowly over the course of the day as the temperature changes. It also tends to turn darker if something threatens it.

It has a thick spiny tail that it usually holds curved upward, which makes it look kind of like a stick. It moves slowly and jerkily, rocking back and forth on its legs, then surging forward a couple of steps. Researchers think this may confuse predators. It certainly looks confusing.

As if that wasn’t enough, the thorny devil has a false head on the back of its neck. It’s basically a big bump with two spikes sticking out of the sides. When something threatens the lizard, it ducks its head between its forelegs, which makes the bump on its neck look like a little head. But all its spines make it a painful mouthful for a predator. If something does try to swallow it, the thorny devil can puff itself up to make itself even harder to swallow, like many toads do. It does this by inflating its chest with air.

The thorny devil eats ants and only ants, specifically various species of tiny black ants found only in Australia. It has a sticky tongue to lick them up. Because it has such a specific diet, it’s hard to keep in captivity. Only a few zoos in Australia have thorny devils on display. If you listened to episode 93, where we talked about invasive ant species having an effect on entire ecosystems, the thorny devil is an example of this. Fortunately the ants it eats are doing just fine, but if an invasive ant species were introduced to the areas where it lives, the thorny devil would probably be in trouble. So no moving ants around, everyone, I mean it.

The thorny devil lives in desert and scrubland regions, and in hot weather it digs a burrow to shelter in. Females lay their eggs in burrows. To get enough water in its desert environment, the thorny devil has microscopic grooves between its scales that suck up water by capillary action. At night dew condenses on the lizard’s body, and it also collects dew by brushing against dewy vegetation or just by standing or lying on damp sand. If it does happen across water in a puddle, it will put a leg in the water and the tiny grooves in its skin suck up water and funnel it to the mouth. It’s like a living straw.

While I was researching this, I found some information on how rattlesnakes drink. When it starts to rain, a rattlesnake will coil up tightly so that rainwater collects in its coils. Then it drinks the water. This sounds like something someone just made up, but it’s real.

Let’s skip right from a snake fact to a weird turtle, because Leo also suggested the mata mata turtle as a topic. This is where I got distracted while researching, and ended up with an entire episode about giant tortoises. If you were wondering, the main difference between a turtle and a tortoise is that turtles spend most or all of their time in water, while tortoises live only on land.

The mata mata turtle lives in shallow, slow-moving water in South America, especially swamps around the Amazon and Orinoco river basins. It isn’t closely related to the snapping turtle of North America, but it does resemble a snapping turtle in some ways. Its shell is brown or black, its skin is grayish, and its plastron, or the belly section of its shell, is yellow or brown. It grows to around two feet long, or 60 cm, with a long, broad neck and wide, triangular head. Its nose comes to a point like the stem of a leaf. In fact, if you look down on a mata mata in the water, the shape of its head looks exactly like a dead leaf. It has notches and ridges on its shell, and its knobbly skin has flaps that helps camouflage the turtle among dead leaves and sticks in the water. It also has claws and webbed toes.

Unlike the snapping turtle, the mata mata is harmless to humans and most animals. It doesn’t have a sharp bill and it won’t bite. It can’t even chew its food, just swallows it whole. It eats fish, water insects, and other small animals that it captures by opening its large mouth suddenly under the water. This creates suction, sucking a lot of water and the prey right into the turtle’s mouth.

The only time the mata mata leaves the water is to lay eggs. Unlike many other turtle eggs, the mata mata eggs have hard shells, more like bird eggs. It takes the eggs about 200 days to hatch.

The mata mata spends almost all of its time motionless in the water, waiting for prey to come near, and occasionally extending its ridiculously long neck so it can take a breath from the surface. Its pointy nose is a proboscis that it breathes through. It can swim, but it usually prefers to walk along the bottom of the pond or marsh. I bet its feet squish in the mud. Squish squish squish.

Speaking of pointy-nosed reptiles, the male Pinocchio lizard has a nose that points forward and slightly upward like a rhinoceros horn. But it’s not a horn, because it’s flexible, made of cartilage. It lives in the Mindo cloud forest in Ecuador, and was only discovered by scientists in 1953, when researchers collected six specimens. And that was the last time anyone saw the Pinocchio lizard—until 2005, when some birdwatchers saw a weird lizard, took pictures and posted them online, and herpetologists started freaking out.

The Pinocchio lizard blends in so well with its environment that it’s hard to spot. It turns white when it’s asleep, which helps it look like part of a tree branch. It always perches on the end of a branch to sleep, too. During the day, it climbs verrry slowly into the treetops. It’s not a big lizard, only about three inches long, or 7.5 cm, not counting its tail, which is as long as its body. We still don’t know much about it because it’s so hard to study.

It’s not the only lizard with a horn on its nose. For instance, the rough-nosed horned lizard lives in Sri Lanka and is an ordinary-looking lizard for the most part, although it’s covered with short bristly scales that make it look like it would work well for scrubbing out dirty pots and pans. But it has a really long nose, also covered in bristly scales. Oh, and yellow or orange markings on its face that make it look like it has a big orange clown mouth. Males have longer horns than females. Male mountain horned agamas, which also live in Sri Lanka, have a single white or cream-colored horn that sticks directly forward from their nose like a tiny unicorn horn, except it’s not spiraled. In fact, it’s not a horn at all, it’s a single big pointy scale. But those lizards aren’t related to the Pinnocchio lizard.

The La Gomera giant lizard doesn’t have any horns and it’s not all that giant, less than two feet long, or around 49 cm long, including the tail. It’s black or brown on its back with a white belly. Males also have a white throat, and during mating season males inflate their throat and bob their head to attract females. It mostly eats plants, although it will eat insects too, and it lives in the Canary Islands. It’s not the most exciting lizard to look at, but it has an interesting history.

The Canary Islands are a group of islands off the coast of Morocco. It was once called the Fortunate Isles, so if you ever see that in an old book you know what islands it’s talking about. Pliny the Elder, a historian from ancient Rome, said the name Canaria came from the number of dogs on the islands. The word for dog in Latin is canis. The people of the islands were supposed to worship dogs, and some modern historians believe the old accounts of dog-headed people may be a garbled account of the Canary Islanders. Oh, and the little yellow songbirds that live on the Canary Islands took their name from the islands, not vice versa.

The islands were probably visited in ancient times by Phoenician and Greek sailors, but reportedly no one lived there when the Romans explored it in the 1st century. But when Europeans returned in the late middle ages, there were inhabitants that may have been settlers from North Africa. The islands were invaded by Europeans, who then spent centuries fighting with each other over who ruled them. It’s Spain, currently. Scientific expeditions started in the late 18th century. One of the animals the expeditions reported seeing was the La Gomera giant lizard, but it disappeared sometime after about 1900. Researchers assumed it had gone extinct.

Then a 1999 expedition from the University of La Laguna on Tenerife, one of the Canary Islands, heard stories from local residents on the island of La Gomera. They said there was a big lizard living in a few places on the island. The biologists in the expedition checked it out…and sure enough, there were giant lizards. Specifically, six of them. Just six lizards. Later they found another small group of the lizards in another area, but the total population was still no more than fifty.

Fortunately, a captive breeding program has been successful and today there are around 250 of the lizards in the wild, living only on two hard to reach cliffs. They’re vulnerable to introduced predators, especially cats, which eat the eggs and young lizards. Another 300 or so live in a recovery center where they’re protected from predators before being released into the wild. So basically, the La Gomera giant lizard isn’t so much strange as just very, very lucky.

Another lizard that is definitely strange is the frilled lizard from northern Australia and southern New Guinea. It’s bigger than the La Gomera giant lizard, almost three feet long, or 85 cm, and eats insects, spiders, and small animals. It lives in trees and is well camouflaged with blotches and spots on a gray or brown background to help camouflage it among branches and against bark.

The frilled lizard gets its name from the frill on eitherside of its head. Most of the time it keeps the frill folded back against itsneck. When it’s threatened, though, it spreads the frill out and opens itsmouth wide. The inside of its mouth is bright yellow or pink, and the frill hasbright red or yellow scales that don’t show when it’s folded. It’s the lizardequivalent of a jump scare in scary movies. Regular lizard, regular lizard…BWAMP BIG SCARY BRIGHT LIZARD

The frill is made up of spines of cartilage that grow from the lizard’s jaw bones, with skin connecting the spines. It’s not small, either. When expanded, it can be almost a foot across, or 25 cm.

The frilled lizard isn’t dangerous, though, and if its threat display doesn’t scare off a predator, it runs away until it finds a tree to climb. It runs so fast, in fact, that it lifts its body up and just runs on its hind legs, which helps it navigate uneven ground and gives it a better view of what’s around it. It also holds its long tail out as a counterweight to keep its body upright.

That’s supposed to be all the strange details about the frilled lizard…but there are sightings of it doing something unexpected on rare occasions. People occasionally report seeing a frilled lizard fall or jump from a tree, and glide down using its frill as a parachute. There’s no proof that this actually happens, but it sounds plausible.

Another Australian lizard called the shingleback, or bobtail, looks kind of like a pinecone with legs. Or a poop with legs, just going to set that down and walk away. It’s brown with darker and lighter speckles or yellow splotches, large overlapping scales, a stubby thick tail, and a broad head. In fact, its head and tail look a lot alike, which confuses predators. It also stores fat in its tail for winter. It grows about a foot long, or 30 cm, and eats snails, insects, flowers, and other small animals and plants. It lives in arid and desert areas, and their tough skin and overlapping scales help reduce water loss. Its eyes are tiny, like little black beads.

The shingleback looks nothing like the frilled lizard, but it has one thing in common with it. When threatened, the shingleback will open its mouth wide and stick out its large, dark blue tongue. It is an impressively blue, impressively big tongue, and the inside of the shingleback’s mouth is otherwise pale, so it’s startling, to say the least.

The shingleback mates for life. Most of the year the shingleback is solitary, but in spring mated pairs find each other again and go around together while they hunt for food. The female gives birth to two live babies instead of laying eggs.

I could go on and on and on about all the weird reptiles in the world. There are just so many! We’ll definitely come back to this topic in the future, but for now, let’s finish up with a snake called Iwasaki’s snail-eater.

The snail-eater lives on a few small islands southwest of Japan’s main islands. It’s small, only about 7 inches long, or 22 cm, and is orangey in color with darker markings and bright orange eyes. And it only eats one thing: snails.

It’s so perfectly adapted to its diet of snails that its jaw is asymmetrical so it can more easily wedge it into the typical snail’s shell, which coils clockwise. If you remember from the little yard animals episode, some snails very rarely coil the opposite way, and the snail-eater snake is so specialized to eat ordinary snails that it has trouble with counter-clockwise coiled snail shells. It has more teeth on its right mandible. There are other snail-eater snakes closely related to Iwasaki’s snail-eater that have this same adaptation, and in some areas where the snakes are numerous, counter-clockwise snails are much more common than in areas without a lot of snail-eater snakes.

So that’s a reminder that whether you’re a little snail-eating snake or a regular human being, the things you do have an effect on the world around you, even if it’s in ways too small for you to notice without looking very closely.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!