Episode 414: Two Marvelous Frogs

Thanks to Eilee and Alexis for their suggestions this week, two amazing frogs!

Further reading:

Paradoxical frog: The giant tadpole that turns into a little frog

Fungus is wiping out frogs. These tiny saunas could save them.

How to build a frog sauna

The paradoxical frog [photo by Mauricio Rivera Correa – http://calphotos.berkeley.edu, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=6703905]:

The Vietnamese mossy frog [photo by H. Zell – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=81804225]:

Show transcript:

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

Let’s start 2025 off right with an episode about frogs! Thanks to Alexis and Eilee for their suggestions.

Let’s start with Eilee’s suggestion, the paradoxical frog. The paradoxical frog is a type of tree frog that lives in South America. Like other frogs, it likes ponds and shallow lakes. Some individuals are green and some are brown, and a frog may have darker stripes or splotches, or might just be plain. The tadpoles eat algae and other tiny food, while the adults eat insects.

As with most frogs, the paradoxical frog hatches into a larval stage called a tadpole or pollywog, which is fully aquatic. It later metamorphoses into its adult form as a frog. Most tadpoles start out very small and grow larger, then metamorphose into a juvenile frog which then grows to fully adult size. But while the paradoxical frog’s tadpole starts out small, it can grow to as much as 11 inches long, or 28 centimeters! It’s the largest tadpole in the world as far as we know.

So how big is the adult frog if the tadpole is so enormous? About 3 inches long, or 7.5 cm, from snout to vent. That’s why it’s called the paradoxical frog, because a paradox is something that seems contradictory to expectations. Instead of the ordinary way of things, where a small tadpole grows into a bigger frog, in this case a big tadpole grows into a smaller frog. It’s sometimes called the shrinking frog.

One interesting detail is that not all of the tadpoles are that big. If a female lays her eggs in a small body of water that’s likely to dry up, or that doesn’t have a lot of food available, or if there are a lot of predators in the water, the tadpole metamorphoses quickly and doesn’t grow very big. But if the tadpole is in a better location it matures much more slowly, which allows it to reach much larger size before metamorphosing.

I should also mention that the 11-inch-long tadpole that is the largest ever measured was actually raised in captivity. In the wild, the largest paradoxical frog tadpole ever measured was 6 ½ inches long, or almost 17 cm. That’s still really big, but not that ridiculously big. But the confusing thing is that the tadpole is big and bulky, up to four times the size of the adult frog. Where does all that mass go after it transforms?

Early scientists who learned about the paradoxical frog wondered the same thing. They were so confused that they suggested that the frog actually came first and later metamorphosed into the tadpole, which then metamorphosed into a fish. But the main reason the tadpole is so long is its tail. When it metamorphoses into a frog, it absorbs the tail and therefore appears to shrink. The bulkiness of the tadpole’s body matches the bulkiness of the frog’s body. And unlike most frogs, which metamorphose into juvenile frogs that still have some growing to do, the paradoxical frog metamorphoses into a completely adult frog. It’s as big as it will ever get and fully mature, ready to mate and lay eggs.

Next, Alexis wanted to learn about the Vietnamese mossy frog. It lives in parts of Vietnam, Laos, and other nearby areas. It prefers mountainous rainforests and the female often chooses to lay her eggs in a tree hollow or even a rock cavity where water has collected. Instead of laying her eggs in the actual water, though, she lays them on rocks or branches above the water. The eggs don’t dry out because of the high humidity in rainforests, and when they hatch, the tadpoles fall into the water.

The tadpoles take a long time to mature, anywhere from four to eight months depending on how warm it is while they’re developing. They grow quite large, although not anywhere near the size of the paradoxical frog tadpole.

A big female Vietnamese mossy frog can grow up to 3 ½ inches long, snout to vent, or 9 cm, and is chubby and round. It’s nocturnal and spends the day hiding on mossy rocks or among plants in the water, then comes out at night to hunt insects like crickets as well as other small animals like worms.

The reason it’s called the mossy frog is because it looks for all the world as though this frog is covered in moss, or maybe is just made out of moss. It’s green and brown in color and its skin is covered in little bumpy structures called tubercules. This helps it blend in incredibly well in the rainforest, where moss is pretty much everywhere. If it feels threatened and it can’t jump into the water to hide, it will play dead.

This is what a Vietnamese mossy frog sounds like:

[frog beeping]

As we’ve talked about in other frog episodes, frogs throughout the world are declining in numbers because of a fungus that infects their skin. The effects of this fungus are worse in cold weather, so a team of scientists speculated that helping the frogs stay warm might help them stay healthier in winter and even help them recover from the infection. They tested their hypothesis by offering infected frogs a variety of temperatures in their enclosure. The frogs could pick where they wanted to spend their time. The frogs liked the warm areas but didn’t spend all their time in them, but they all recovered from the infection. Frogs who were given an overall warm environment also recovered, but not as fast. Frogs who had an ordinary enclosure without warmer areas remained infected with the fungus. Even better, frogs who had recovered from infection with the warm environment also showed resistance to later infections.

The team worked to develop plans that allow people to easily build what they call frog saunas. They don’t require electricity or fuel, just sunshine. When the saunas are placed near ponds or other areas with frogs, the frogs find them quickly and use them. There’s a link in the show notes if you want to learn how to make a frog sauna for your own back yard.

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 412: Whales and Dolphins

Thanks to Elizabeth, Alexandra, Kimberly, Ezra, Eilee, Leon, and Simon for their suggestions this week!

Further reading:

New population of blue whales discovered in the western Indian Ocean

An Endangered Dolphin Finds an Unlikely Savior–Fisherfolk

The humpback whale:

The gigantic blue whale:

The tiny vaquita:

The Indus river dolphin:

The false killer whale:

Show transcript:

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

This week we’re going to have a big episode about various dolphins and whales! We’ve had lots of requests for these animals lately, so let’s talk about a bunch of them. Thanks to Elizabeth, Alexandra, Kimberly, Ezra, Eilee, Leon, and Simon for their suggestions.

We’ll start with a quick overview about dolphins, porpoises, and whales, which are called cetaceans. All cetaceans alive today are carnivorous, meaning they eat other animals instead of plants. This includes the big baleen whales that filter feed, even though the animals they eat are tiny. Cetaceans are mammals that are fully aquatic, meaning they spend their entire lives in the water, and they have adaptations to life in the water that are simply astounding.

All cetaceans alive today belong to either the baleen whale group, which filter feed, or the toothed whale group, which includes dolphins and porpoises. The two groups started evolving separately about 34 million years ago and are actually very different. Toothed whales are the ones that echolocate, while baleen whales are the ones that have extremely loud, often beautiful songs that they use to communicate with each other over long distances. It’s possible that baleen whales also use a limited type of echolocation to navigate, but we don’t know for sure. There’s still a lot we don’t know about cetaceans.

Now let’s talk about some specific whales. Ezra wanted to learn more about humpback and blue whales, so we’ll start with those. Both are baleen whales, specifically rorquals. Rorquals are long, slender whales with throat pleats that allow them to expand their mouths when they gulp water in. After the whale fills its mouth with water, it closes its jaws, pushing its enormous tongue up, and forces all that water out through the baleen. Any tiny animals like krill, copepods, small squid, small fish, and so on, get trapped in the baleen. It can then swallow all that food and open its mouth to do it again. The humpback mostly eats tiny crustaceans called krill, and little fish.

The humpback grows up to 56 feet long, or 17 meters, with females being a little larger than males on average. It’s mostly black in color, with mottled white or gray markings underneath and on its flippers. Its flippers are long and narrow, which allows it to make sharp turns.

The humpback is closely related to the blue whale, which is the largest animal ever known to have lived. It can grow up to 98 feet long, or 30 meters, and it’s probable that individuals can grow even longer. It can weigh around 200 tons, and by comparison a really big male African elephant can weigh as much as 7 tons. Estimates of the weight of various of the largest sauropod dinosaurs, the largest land animal ever known to have lived, is only about 80 tons. So the blue whale is extremely large.

The blue whale only eats krill and lots of it. To give you an example of how much water it can engulf in its enormous mouth in order to get enough krill to keep its massive body going, this is how the blue whale feeds. When it finds an area with a lot of krill floating around, it swims fast toward the krill and opens its giant mouth extremely wide. When its mouth is completely full, its weight—body and water together—has more than doubled. Its mouth can hold up to 220 tons of water. Since the whale is in the water, it doesn’t feel the weight of the water in its mouth.

Blue whales live throughout the world’s oceans, but a few years ago scientists analyzing recordings of whale song from the western Indian Ocean noticed a song they didn’t recognize. It was definitely a blue whale song, but one that had never been documented before. Not long after, one of the same scientists was helping analyze humpback whale recordings off the coast of Oman and recognized the same unusual blue whale song.

After the finding was announced, other scientists checked their recordings from the Indian Ocean and a few realized they had the mystery blue whale song too. The recordings come from a population of blue whales that hadn’t been documented before, and which may belong to a new subspecies of blue whale.

Elizabeth, Alexandra, and Leon all wanted to learn about dolphins. Kimberly also specifically wanted to learn about the Indus River dolphin and Leon about the vaquita porpoise. Dolphins and porpoises are considered toothed whales, but they’re also relatively small and can swim very fast. Orcas are actually dolphins even though they’re often called killer whales.

Even a small cetacean is really big, but the exception is the vaquita. It’s the smallest cetacean alive today, not even five feet long, or 1.5 meters. It lives only in the upper Gulf of California and is gray above and white underneath, with black patches on its face.

The vaquita spends very little time at the surface of the water, so it’s hard to spot and not a lot is known about it. It mostly lives in shallow water and it especially likes lagoons with murky water, since that’s where it can find lots of the small animals it eats, including small fish, squid, and crustaceans.

The vaquita is critically endangered, mostly because it often gets trapped in illegal gillnets and drowns.  There may be as few as ten individuals left alive. Attempts at keeping the vaquita in captivity have failed, but it’s strictly protected by both the United States and Mexico. Some scientists worry that even though vaquita females are still having healthy calves, there are so few of the animals left that they might not recover and are functionally extinct. But only time will tell, so the best thing everyone can do is what we’re already doing, keeping the vaquita and its habitat as safe as possible.

Another small cetacean is the Indus River dolphin, which grows up to 8 and a half feet long, or 2.6 meters. As you can probably guess from its name, it actually lives in fresh water instead of the ocean, specifically in rivers in Pakistan and India. It’s pinkish-brown in color and has a long rostrum, or beak-like nose, which turns up slightly at the end and is filled with sharp teeth that it uses to catch fish and other small animals. Because the rivers where it lives are murky, the dolphin doesn’t have very good eyesight. It probably can’t see anything except light and dark with its tiny eyes, but it can sense its surroundings just fine with echolocation.

Like most cetaceans, the Indus River dolphin is endangered, but it’s doing a lot better these days than it was just a few decades ago. In the 1970s only about 150 of the little dolphins were left alive, and by 2001 there were a little over 600. Today there are around 2,000. Habitat loss, pollution, and accidental drowning in fishing nets are still ongoing problems, but these days the fishing families that live along the river are helping it whenever they can. The fishers rescue dolphins who get stranded in shallow water and irrigation canals, and the government encourages this by paying the fishers a small amount for their help. Since this part of the country is very poor, a little bit of extra money can mean a big difference for the families, and of course their help means a lot to the dolphins too.

One interesting thing is that the Indus River dolphin often swims on its side. That is, it just tips over sideways and swims around as though that’s the most normal thing in the world. Scientists think this helps it navigate shallow water. And the Indus River dolphin isn’t very closely related to other dolphins and whales.

Quite a while ago now, Simon brought the false killer whale to my attention. In 1846 a British paleontologist published a book about British fossils, and one of the entries was a description of a dolphin. The description was based on a partially fossilized skull discovered three years before and dated to 126,000 years ago. It was referred to as the false killer whale because its skull resembled that of a modern orca. Scientists thought it was the ancestor of the orca and that it was extinct.

Or maybe not, because in 1861, a dead but very recently alive one washed up on the coast of Denmark.

The false killer whale is dark gray and grows up to 20 feet long, or 6 meters. It mostly eats squid and fish, including sharks. It’s not that closely related to the orca and actually looks more like a pilot whale. It will sometimes hang out with dolphins, including occasionally hybridizing with bottlenose dolphins, but then again sometimes it will eat dolphins. Watch out, dolphins.

Finally, Eilee wanted to learn about little-known whales, and that definitely means beaked whales. There are 24 known species of beaked whale, but there may still be species unknown to science. We know very little about most of the known species, because they live in remote parts of the ocean. They prefer deep water and are extremely deep divers, with the Cuvier’s beaked whale recorded as diving as deep as 1.8 miles, or almost 3 km, and staying underwater without a breath for 222 minutes. That’s approximately 220 minutes longer than a human can hold their breath.

Let’s finish with Sato’s beaked whale, which was only described in 2019. It’s black with a chunky body and small flippers and dorsal fin. It also has a short beak. It lives in the north Pacific Ocean and was thought to be a darker population of Baird’s beaked whale, which is gray, but genetic studies and a careful examination of dead beached individuals proved that it was a completely different species. It grows up to 23 feet long, or 7 meters, but since no female specimens have ever been found, we don’t know if the female is larger or smaller than the male.

We basically know nothing about this whale except that it exists, and the fact that it is alive and swimming around in the ocean right now, along with other whales, is an amazing, wonderful thing.

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 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 399: Bears

Thanks to Anbo, Murilo, Clay, and Ezra for their suggestions this week! Let’s learn about some bears!

Further reading:

Snack attack: Bears munch on ants and help plants grow

Extinct vegetarian cave bear diet mystery unravelled

Ancient brown bear genomes sheds light on Ice Age losses and survival

The sloth bear has shaggy ears and floppy lips [photo from this site]:

An absolute unit of a Kodiak bear in captivity [photo by S. Taheri – zoo, own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1118252]:

A polar bear:

Show transcript:

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

This week we’re revisiting a popular topic, bears! We’ll talk about some bears we’ve never covered before, with suggestions from Anbo, Clay, Ezra, and Murilo. We’ll even discuss a small bear mystery which has mostly been solved by science.

To start us off, Anbo wanted to learn about bears in general. We’ve had bear episodes before, but our last episode all about bears was way back in 2017, in episode 42. Some of our listeners weren’t even born back then, which makes me feel super old.

Bears live throughout much of the world today, but they evolved in North America around 38 million years ago. These ancestral bears were small, about the size of a raccoon, but they were successful. They spread into Asia via the land bridge Beringia, where they were even more successful than in North America, so successful that by around 30 million years ago, descendants of those earliest bear ancestors migrated from Asia back into North America. But it wasn’t until the Pleistocene around 2 ½ million years ago that bears really came into their own.

That’s because bears are megafauna, and megafauna evolved mainly as an adaptation to increasingly cold climates. As the ice ages advanced, a lot of animals grew larger so they could stay warm more easily. Predators also had to grow larger as their prey became larger, since if you want to hunt an animal the size of a bison or woolly rhinoceros, you’d better be pretty big and strong yourself.

Bears mostly weren’t hunting animals that big, though. Modern studies suggest that overall, bears are omnivores, not fully carnivorous. Bears eat a lot of plant material even if you don’t count the panda, which isn’t very closely related to other bears. Even when a bear does eat other animals, they’re not usually very big ones.

Let’s take Murilo’s suggestion as an example, the sloth bear. The sloth bear lives in India and is increasingly vulnerable due to habitat loss and poaching. It’s probably most closely related to the sun bear that we talked about in episode 234, which also lives in parts of South Asia. Both the sun bear and the sloth bear have long black hair and a white or yellowish V-shaped marking on the chest. The sloth bear’s hair is especially long on its neck and shoulders, like a mane, and its ears even have long hair.

The sloth bear stands around 3 feet high at the shoulder at most, or 91 cm, and a big male can be over 6 feet tall, or almost 2 meters, when he stands on his hind legs. This isn’t gigantic for bears in general, but it’s not small either. Scientists think the V-shaped marking on its chest warns tigers to leave the sloth bear alone, and tigers mostly do. If tigers think twice about attacking an animal, you know that animal has to be pretty tough.

The sloth bear has massive claws on big paws. The claws can measure 4 inches long, or 10 cm, although they’re not very sharp. The bear has an especially long muzzle but its teeth aren’t very large. Like most bears, it’s good at climbing trees and can run quite fast, and it swims well too. It even has webbed toes.

With all this in mind, what do you think the sloth bear eats? I’ll give you some more hints. It has loose, kind of flappy lips, especially the lower lip. It doesn’t have any teeth in the front of its upper jaw. It mainly uses its huge claws to dig.

If you guessed that the sloth bear eats ants, termites, and other insects, you are right! It digs into termite and ant nests and uses its long, flexible lips to slurp up as many insects as it can, giving them a quick crunch with its back teeth before swallowing them down.

Insects are actually quite nutritious, and the sloth bear isn’t the only bear that eats them. All bears snack on ants and other insects sometimes. You may have heard that bears love honey and will tear open beehives to get it, and while that’s true, the bear is mainly after the larval bees because they’re so nutritious. The honey is just, you know, dessert.

Next, Clay wanted to learn about the Kodiak bear, which may be the largest bear in the world. It’s a subspecies of brown bear and is sometimes called the Alaskan brown bear since it lives on some Alaskan islands called the Kodiak Archipelago. It’s light brown or rusty-red in color.

The Kodiak bear has been restricted to these islands for at least 10,000 years, since the end of the Pleistocene when the sea levels rose as glaciers melted. It demonstrates island gigantism, which is actually quite unusual. Because islands have limited resources, but are relatively protected from large numbers of predators, small animals are the ones that generally adapt to island life by growing larger. Animals that start off large generally adapt by growing smaller, called island dwarfism. That’s why some islands have been home to dwarf elephants but giant rodents.

In the case of the Kodiak bear, it has a source of protein that helps it grow so incredibly large, salmon. Five species of salmon spawn in the freshwater on the islands, and the bears are able to put on lots of weight to survive the harsh winter by eating as much salmon as they can catch. They also have lots of nutritious plants to eat. They actually prefer some plants to eating salmon, which makes sense when you think about it. A wild animal needs to conserve energy, and it can take a lot of energy to catch fish. It’s a lot easier to eat berries, which can’t swim away.

So how big can a Kodiak bear get? A big male can stand up to 10 feet tall on his hind legs, or 3 meters, and be 5 feet tall, or 1.5 meters, when standing on all fours. Bears kept in captivity can grow even larger. That’s much bigger than a grizzly and about the same size as the closely related polar bear, which brings us to Ezra’s suggestion.

Ezra wanted to learn about the polar bear, which lives in the Arctic and areas near the Arctic. It doesn’t live near the Antarctic, or south pole, which means polar bears don’t eat penguins, because penguins live around the Antarctic. The polar bear does eat a whole lot of other animals, though, and is the most carnivorous of all bears. It especially likes eating seals, and will also catch and kill walruses, caribou, and beluga whales. That’s right, the polar bear can actually kill an entire whale. The beluga is fairly small for a whale and relies on breathing holes in the ice, and sometimes when it comes up to breathe, there’s a polar bear waiting for it. Most of the time, though, the polar bear eats much smaller animals.

The polar bear spends a lot of its time on sea ice, and a lot of the time in the sea. It swims incredibly well and spends so much time in the water that some people consider it a marine animal. It’s certainly semi-aquatic. Its kidneys are adapted to filter excess salt out of its blood from seawater, and its small eyes are closer to the top of its head than in other bears. This helps it see above water while swimming.

The polar bear is closely related to the brown bear and will sometimes interbreed with the brown bear where their ranges overlap. The resulting hybrid bear is usually light brown in color. The polar bear is famously white, although its fur becomes yellowish as the year goes on. It sheds its winter coat in the spring and the new hair that grows in is white.

Actually, the polar bear’s fur is transparent, but it looks white because of the way it scatters light. The guard hairs are long and coarse, protecting a shorter, softer undercoat that helps keep the bear warm even on bitterly cold nights. Unlike other bears, the polar bear doesn’t hibernate, except for pregnant females.

There used to be a bear of similar size that lived in Europe and Asia during the Pleistocene and only went extinct about 24,000 years ago. The cave bear gets its name because so many of its remains have been found in caves. It may have hibernated in caves like some bears do today, or it might have used caves as shelters year-round.

Scientists think the cave bear was most closely related to brown bears and polar bears. The males were much larger than females, and a big male was as big as a Kodiak or polar bear. But this giant bear probably wasn’t too much of a problem for our ancient ancestors and Neandertal relations, because it was almost entirely vegetarian.

Scientists have studied the wear pattern on cave bear teeth and determined that it was eating a whole lot of fruit, especially berries. It probably did eat at least some meat, but it’s likely that most of it came from scavenged carcasses. The cave bear didn’t even have all the teeth that other bears have.

All this talk about huge bears brings us to a mystery. It may even be a mystery you were wondering about yourself. How did bears survive the end of the Pleistocene when so many other megafauna went extinct, from the mammoth and giant ground sloth to the dire wolf and sabertooth cat?

A team of scientists from Denmark and Japan decided to examine the genetics of ancient brown bears, to learn how individuals were related and therefore how bears migrated across the world over time. They extracted genetic material from the remains of bears that lived as much as 60,000 years ago and as recently as 3,800 years ago and compared them to each other and to bears alive today.

Scientists already knew that brown bears used to live in more parts of the world than they do today. The prevailing view was that as the climate warmed after the ice ages, the bears retreated into colder parts of the world where they were more comfortable. But the team learned something surprising from the study, which was published in January of 2024.

Brown bears that lived before the end of the Pleistocene, approximately 11,000 years ago, had much broader genetic diversity than the bears that lived more recently. That means that bears that lived as far south as Japan and Ireland during the Pleistocene didn’t move to colder parts of the world, they died out. Each population that went regionally extinct made the brown bear gene pool that much smaller.

Most likely it was a combination of luck and adaptability that allowed bears to survive the end-Pleistocene extinctions. Just think how sad it would be if I ended this episode by saying that bears went extinct 11,000 years ago. Instead, we can still go to the zoo and see all kinds of bears whenever we want to.

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 398: Repeating Scientific Names

Thanks to Alexandra, Pranav, Eilee, Conner, and Joel for their suggestions this week!

Velella velella, or by-the-wind-sailor [photo from this page]:

Porpita porpita, or the blue button [photo from this page]:

Cricetus cricetus, or the European hamster, next to a golden hamster:

Nasua nasua, or the South American coati [photo from this page]:

Mola mola, or the ocean sunfish:

Quelea quelea, or the red-billed quelea [photo from this page]:

Show transcript:

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

This week we’re going to learn a little bit about scientific names, and along the way we’re going to learn about several animals. Thanks to Alexandra, Eilee, Conner, Joel, and Pranav for their suggestions!

Alexandra inspired this episode by suggesting two animals, the by-the-wind-sailor and the blue button. Both are marine invertebrates that look superficially like jellyfish, but they’re actually colonial organisms. That means that although they look like a single animal, they’re actually made up of lots of tiny animals that live together and function as one organism.

The blue button is closely related to the by-the-wind-sailor and both are related to siphonophores. Both the blue button and the by-the-wind-sailor spend most of the time near or on the ocean’s surface and have a gas-filled chamber that helps keep them afloat, with stinging tentacles that hang down into the water, but both are made up of a colony of tiny animals called hydroids. Different hydroids have different functions, and all work together to find tiny food that will benefit the entire colony.

The blue button gets its name because its float is round and flat like a button, and often blue or teal in color. It’s quite small, only a little over an inch across, or about 3 cm, and its tentacles are not much longer. The by-the-wind-sailor is a little larger than the blue button, with a blue sail-shaped float that’s only a few inches across, or maybe 7 cm, with stinging tentacles of about the same size. The stings of both organisms aren’t very strong and aren’t dangerous to humans, but they do hurt, so it’s a good idea not to touch one. Since both can be very common in warm ocean waters and they sometimes get blown ashore by the wind in large numbers, it can be hard to avoid them if you’re visiting the beach at the wrong time. They can still sting you if they’re dead, too.

The by-the-wind sailor has the scientific name of Velella velella while the blue button’s scientific name is Porpita porpita. The term for a scientific name that contains the same words is a repeating scientific name, also called a tautonym or tautonymous name, and that’s the subject of this episode.

A scientific name is something we mention a lot but if you’re not sure what it means, it can sound confusing. Every organism with a scientific name has been described by a scientist, meaning it’s been studied and placed somewhere in the great interconnected web of life. The system of giving organisms scientific names is called binomial nomenclature. The first word of the name indicates which genus the organism belongs to, while the second word indicates what species it is. These are called generic and specific names. Some organisms also have a third word in their scientific name which indicates its subspecies.

The reason scientists use a complicated naming system is to make it easier for other scientists to know exactly what organism is being discussed. For example, let’s say a scientist has been studying hamsters in the wild to learn more about them, and publishes a paper about her observations. If she just calls the animal a hamster, someone reading it might assume she was talking about the hamster found in their part of the world, when the paper is actually about a totally different, although closely related, hamster that lives somewhere else. And that brings us to Pranav’s suggestion, the European hamster, whose scientific name is Cricetus cricetus [cry-SEE-tus].

The hamster most of us are familiar with is actually the golden hamster, also called the Syrian hamster, more properly called Mesocricetus auratus. That’s the most common species kept as a pet. We can learn from the different scientific names that the European hamster is in a different genus from the golden hamster, which usually means it’s pretty different in some significant ways.

The European hamster lives throughout parts of Eurasia, especially eastern Europe through central Asia, and used to be extremely common. It’s also called the black-bellied hamster because the fur on its underside is black, while the fur on its upper side is tan or brown with white markings. These days it’s critically endangered due to habitat loss and being killed by farmers who think it hurts their crops. It does eat seeds, vegetables, and some roots, but it also eats grass and many other plants that are considered weeds, as well as insects, including insects that farmers also don’t want in their gardens.

In many respects, the European hamster is a lot like the golden hamster. It carries food home to its burrow in its cheek pouches and stores food in a larder. It hibernates in cold weather but wakes up around once a week to have a snack from its larder, which honestly sounds like the best way to spend the winter. But the European hamster is larger than the golden hamster. Like, a lot larger. The golden hamster is maybe 5 inches long, or 13 cm, which is small enough that you can easily hold it in your hand. The European hamster grows up to 14 inches long, or 35 cm. That’s the size of a small domestic cat, but with a short little hamster tail and short little hamster legs.

Even though an organism’s scientific name only designates genus and species, and subspecies when applicable, it allows scientists to look up a more detailed family tree. Every genus is classified in a family and every family is classified in an order, and every order in a class, and every class in a phylum, and every phylum in a kingdom, and every kingdom in a domain. Almost all of the organisms we talk about in this podcast belong to the kingdom Animalia. The more of these categories an organism shares with another organism, the more closely related they are.

Conner suggested we learn more about the coati, which we talked about in episode 302. The South American coati’s scientific name is Nasua nasua [NAH-sue-uh]. It grows almost four feet long, or 113 cm, which makes it sound enormous, but half of its length is its long ringed tail. It lives in much of South America, especially the northern part of the continent.

The coati is related to the raccoon of North America, and the two animals’ scientific names can help us determine how closely they’re related. The common raccoon’s scientific name is Procyon [PROSE-eon] lotor, so we already know it belongs to a different genus than the coati. But both the genus Procyon and the genus Nasua are classified in the family Procyonidae. So we know they’re closely related, because they belong to the same family, but not as closely related as they’d be if they belonged to the same genus, so we can expect to see some fairly significant differences between the two animals.

The South American coati is diurnal, unlike the nocturnal raccoon. While female raccoons often live in small groups of a few animals that share the same territory, female coatis live in groups of up to 30 animals who forage for food together and are very social. The coati also doesn’t have a set territory. The male coati is completely solitary, while the male raccoon will also live in small groups of three or four animals. Both are omnivorous but the coati eats more fruit and insects than the raccoon does, and the coati doesn’t dunk its food in water the way the raccoon famously does.

The system of binomial nomenclature that we use today was developed by the Swedish botanist Carolus Linnaeus in 1735. We talked about some of his mistakes in episode 123. Linnaeus built on a system developed by a zoologist almost a century before him, but streamlined it and made it easier to use. In the 300 years since Linnaeus came up with his system, many other scientists have made changes to reflect increased knowledge about the natural world and how best to denote it.

I keep saying “organism” instead of “animal,” and that’s because all living organisms may be given a scientific name as they are described. This includes everything from humans to maple trees, from earthworms to harpy eagles, from bumblebees to mushrooms. Linnaeus originally included minerals in his classification system, but minerals don’t evolve the way living organisms do. One group that wasn’t given scientific names until 2021 are viruses. There’s still a lot of controversy as to whether viruses are technically alive or not, but giving them scientific names helps organize what we know about them.

Eilee suggested the ocean sunfish, which has the scientific name Mola mola. Because its scientific name is easy to say, and because there’s also a freshwater sunfish that isn’t related to the ocean sunfish, a lot of people just call it the mola-mola, or just the mola. We talked about it way back in episode 96, so we’re definitely due to revisit it.

The ocean sunfish doesn’t look like a regular fish. It looks like the head of a fish that had something humongous bite off its tail end. It has one tall dorsal fin and one long anal fin, and a little short rounded tail fin that’s not much more than a fringe along its back end. This isn’t even a real tail but part of the dorsal and anal fins. The sunfish uses the tail fin as a rudder and progresses through the water by waving its dorsal and anal fins the same way manta rays swim with their pectoral fins. Pectoral fins are the ones on the sides, while the dorsal fin is the fin on a fish’s back and an anal fin is a fin right in front of a fish’s tail. Usually dorsal and anal fins are only used for stability in the water, not propulsion. The ocean sunfish does have pectoral fins, but they’re tiny.

The ocean sunfish lives mostly in warm oceans around the world, and it eats jellies, small fish, squid, crustaceans, plankton, and even some plants. It has a small round mouth that it can’t close and four teeth that are fused to form a sort of beak. It also has teeth in its throat, called pharyngeal teeth. Its skin is thick and rough like sandpaper with a covering of mucus, and its bones are mostly cartilaginous. It likes to sun itself at the water’s surface, and it will float on its side like a massive fish pancake and let sea birds stand on it and pick parasites from its skin. This also helps it absorb heat from sunlight after it’s been hunting in deeper water.

The female ocean sunfish can lay up to 300 million eggs at a time. That is the most eggs known to be laid by any vertebrate. When the eggs hatch, the larval sunfish are only 2 ½ mm long. Once they develop into their juvenile form, they have little spines all around their thin end, which kind of make them look like tiny stars. If that seems weird, consider that the ocean sunfish is actually related to the pufferfish, although not very closely. The largest adult ocean sunfish ever reliably measured was 14 feet tall, or 4.3 meters, including the long fins, which is a whole lot bigger than 2 ½ mm.

Sometimes after an organism is initially described and named, later scientists learn more about it and determine that it doesn’t actually belong in the genus or family where it was initially placed. If it gets moved to a different genus, its scientific name also needs to change. Some organisms get moved a lot and their scientific names change a lot. But typically, the species name doesn’t change. That’s the case for a little bird from Africa.

Joel suggested a bird called the red-billed quelea [QUEE-lee-ya], whose scientific name is Quelea quelea. When Linnaeus described it in 1758, he thought it was a type of bunting, so he named it Emberiza quelea. Another scientist moved it into a new genus, Quelea, in 1850.

I’d never heard of the red-billed quelea, which is native to sub-Sarahan Africa, but it may actually be the world’s most numerous non-domesticated bird, with an estimated 1.5 billion birds alive at any given moment.

The red-billed quelea mainly eats grass seeds, and unlike the European hamster, it is actually a problem to farmers. The bird doesn’t know the difference between yummy grass seeds and yummy wheat, barley, milt, oats, sunflowers, and other food that humans eat. In fact, some researchers suggest that the bird has become incredibly numerous because it has all this great food to eat that was planted by people.

A flock of red-billed quelea birds can number in the millions. The flock flies until they find grassland or fields with food they like. The first birds land, the birds behind them land a little bit farther along, and so on until all the birds have landed and are eating. But by the time the last birds of the flock land, the first ones have eaten everything they can find, so they fly up and over the rest of the birds until they find fresh grass to land in again. This is happening constantly with the entire flock of millions of birds, so that from a distance the flock’s movement looks like a cloud of smoke rolling across a field.

The red-billed quelea also eats insects, mostly during nesting season. Insects and other small invertebrates like spiders are especially nutritious for nestlings.

The quelea is about the size of a sparrow, which it resembles in many ways, although it’s actually a member of the weaver bird family, Ploceidae. It grows less than five inches long, or about 12 cm, including its tail, and it’s mostly brown and gray. Its beak and legs are orangey-red, and during breeding season the male has a rusty-red head with a black mask on his face.

One subspecies of red-billed quelea is native to western and central Africa. Since it’s a subspecies, it has three words in its scientific name: Quelea quelea quelea.

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 397: Some Colorful Fishies

Thanks to Cosmo, William, and Silas for their fishy suggestions this week!

You have until Sept. 13, 2024 to back the enamel pin Kickstarter!

Further reading:

The Handfish Conservation Project

Researchers Look in Tank and See Promising Cluster of Near-Extinct Babies

The unique visual systems of deep sea fish

A red handfish:

Another red handfish. This one is named Hector:

The black dragon fish:

The white-edged freshwater whipray [photo by Doni Susanto]:

Show transcript:

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

This week we return to the vertebrate world, specifically some strange and colorful fishies. Thanks to William, Cosmo, and Silas for their suggestions!

We’ll start with Silas’s suggestion, the red handfish. We talked about it before back in episode 189, but it’s definitely time to revisit it. When we last discussed it, scientists estimated there were fewer than 100 red handfish left in the wild, meaning it was in imminent danger of extinction. Let’s find out how it’s doing now, four years later.

The handfish gets its name because its pectoral fins look like big flat hands. It spends most of its time on the sea floor, and it uses its hands to walk instead of swimming. It can swim, although it’s not a very strong swimmer, and anyway if you had great big hands you might choose to walk on them too. It doesn’t have a swim bladder, which helps most fish stay buoyant.

All species of handfish are small, only growing to about 6 inches long at most, or 15 cm. This is surprising considering the handfish is closely related to anglerfish, and some anglerfish can grow over 3 feet long, or about a meter.

As for the red handfish specifically, it generally only grows about 4 inches long at most, or 10 cm, and it once lived in shallow water around much of Australia. These days, it’s only found on two reefs southeast of Tasmania. Some populations are bright red while some are pink with red spots. It has a wide downturned mouth that makes it look like a grumpy red toad with big hands.

So how is the red handfish doing? Four years ago it was almost extinct in wild, with fewer than 100 individuals alive. These days the Handfish Conservation Project estimates that the wild population is probably about the same, although because the red handfish is so small and hides so well among sea grass, algae, and rocks that make up its home, it’s hard to get a good count of how many are really alive. It’s also under even more pressure than before as an overpopulation of urchins is overgrazing the plants where it lives, which may sound familiar to you if you listened to episode 395 a few weeks ago. But there is one fantastic change that gives conservationists hope that the red handfish won’t go extinct after all.

The red handfish is so endangered, and its remaining habitat is so small, that a few years ago scientists decided they needed to start a captive breeding program. But even though the fish did just fine in captivity, they didn’t breed at first. Then, in November 2023, one of the fish laid 21 eggs and all 21 hatched safely. Hopefully it won’t be long until the babies are old enough to release into the wild.

The red handfish is one of very few fish that hatch into tiny baby fish instead of into a larval form. Newly hatched babies are only about 5 mm long. Most fish colonize new habitats after they float around aimlessly as larvae, until they grow enough to metamorphose into adults. Since the red handfish doesn’t have this larval stage, and babies just walk around on the sea floor finding tiny worms and other food, it’s hard for the fish to expand its range. Hopefully, as the captive breeding program continues and more young fish are released into the wild, scientists can start releasing red handfish into areas where they used to live.

Next, William asked about the dragon fish. We’ve talked about a few dragonfish before, in episodes 193 and 231, but there are lots of species in many genera in the family Stomiidae. Many have barbels with photophores at the end that lure prey, and most have long needle-like teeth and jaws that can open incredibly wide. They also have stretchy stomachs so they can hold whatever they manage to catch. As you may have guessed from these traits, the dragon fish lives in the deep sea where there’s little or no light from the surface.

You may wonder why deep-sea fish even have eyes if there’s no light. Fish that live in cave systems eventually evolve to be eyeless, since they don’t need their eyes to see and growing eyes is just a waste of their energy. It’s because even though there’s no sunlight in the deep sea, there is light from lots of different organisms. Many, many deep-sea animals produce bioluminescent light to attract mates or trick smaller animals into coming closer.

Any sunlight that does find its way to the depths of the ocean is blue, because blue has the shortest wavelength and can travel farther. Red wavelengths are longest so that red is the first color lost when you start descending into the water. One article that I’ve linked to in the show notes mentions that if a diver gets a cut, the blood looks brown or even black if the water is deep enough. That’s creepy.

As a result, deep-sea fish are most sensitive to the color blue. Most of them can’t perceive red at all because there just isn’t any red in their environment. And that’s where the dragon fish comes in, because some species of dragon fish can not only see red, they produce red light that illuminates everything around them. A fish or other animal swimming along has no idea that it’s lit up like it’s under a red spotlight because it can’t even see that color.

At least one species, the black dragon fish, perceives red light very differently from the way other animals do. As far as we know it’s unique among all animals. Its eyes contain a photosensitizer derived from chlorophyll, which allows it to see shorter lightwaves. Chlorophyll is found in plants and some bacteria, and it’s actually a specialized pigment that absorbs energy from light. It’s the reason why plants are green. But the black dragonfish uses the chlorophyll it digests to perceive red light.

But remember how dragon fish have giant sharp fangs and will eat pretty much anything they can swallow? Where does the black dragon fish get the chlorophyll it needs? There aren’t any plants in the deep sea anyway.

The answer seems to be that the black dragon fish eats a whole lot of copepods, tiny crustaceans that live throughout the world. The particular species of copepods that the black dragon fish prefers contain a type of chlorophyll.

Finally, Cosmo wanted to learn about the freshwater stingray. We talked about it in episode 296, but mostly we concentrated on the South American fish in that episode. There are freshwater stingrays that live in other parts of the world, such as Asia. This includes the white-edge freshwater whipray, which is extremely rare and only found in four rivers in Southeast Asia.

The white-edge freshwater whipray grows up to two feet across, or 60 cm, with a thin tail about two and a half times longer than the body itself so that technically it can grow around 6 and a half feet long, or 2 meters. Most of that length is tail, though. It’s mostly brown so it can hide in the sandy mud at the bottom of the river, with black dermal denticles down the middle of its back. The tail is mostly white, though, and has two long stinging spines that can be over 3 inches long, or 8 cm.

While the white-edged whipray lives in rivers, it can also tolerate brackish water where the ocean and the river waters mix. It eats small animals it finds on the bottom of the river, including crustaceans and mollusks. It’s endangered due to habitat loss, overfishing, and pollution.

The white-edged whipray is so rare these days that it’s unlikely that anyone would accidentally step on one in the water. But if they did, the ray would whip its long tail up and jab the spines into the person’s leg or foot. The spines can do a lot of damage on their own, but the venom they inject makes the wound incredibly painful and can even potentially kill the person.

If you plan to do some wading in a South Asian river anytime soon, make sure to shuffle your feet as you walk to scare away any potential whiprays before you step right on it.

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 396: Moths!

Thanks to Joel and an anonymous listener for their suggestions this week!

Further reading:

Dieback and recovery in poplar and attack by hornet clearwing moth

The enormous and beautiful Atlas moth:

A male hairy tentacle moth without and with coremata extended [photos from this site]:

The hornet moth looks like a hornet but can’t sting:

Show transcript:

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

Welcome to September, where we’re mere weeks away from Monster Month! Invertebrate August is over for another year, but what’s this? An episode about moths?! Hurrah for one extra invertebrate episode, because they don’t get enough attention on this podcast! Thanks to Joel and an anonymous listener for their suggestions.

First, a listener who wants to remain anonymous suggested that we talk about moths in general, and the Atlas moth in particular. I like the Atlas moth because you can catch it in Animal Crossing. It’s also beautiful and one of the largest moths in the entire world. Its wingspan can be well over 10 inches across, or about 27 cm, which is bigger than a lot of bird wingspans.

The Atlas moth’s wings are mostly cinnamon brown with darker and lighter spots. The upper wings have a curved sort of hook at the top that’s lighter in color and has an eyespot. It looks remarkably like a snake head, and in fact if a predator approaches, the moth will move its wings so that it looks like a snake is rearing its head back to strike.

Despite having such huge wings, atlas moths don’t fly very well. That’s okay because they only need to be able to fly for a few days, which they mostly do at night. They’re only looking for a mate, not food, because they don’t even have fully formed mouthparts. They don’t eat as adults. Like many moths, they mate, lay eggs, and die.

A few weeks later, the eggs hatch and the baby caterpillars emerge. The caterpillar is pale green with little spikes all over, and it eats plants until it grows to around 4 and a half inches long, or about 11 and a half cm. At that point it spins a cocoon attached to a twig, hidden from potential predators by dead leaves that the caterpillar incorporates into the cocoon’s outside.

The Atlas moth lives in forests in southern Asia, including China, India, Indonesia, and Malaysia, with a subspecies native to Japan. Its cocoons are sometimes collected to use for silk. The silk isn’t as high a quality as the domesticated silk moth’s, but it’s very strong and since the cocoons are so big, they produce lots of silk. Sometimes people will collect a cocoon after the moth has emerged and use it as a little purse.

Next, Joel suggested two interesting moths. The first is often called the hairy tentacle moth, which sounds absolutely horrifying. Its scientific name is Creatonotos gangis, and it lives in parts of Australia and southeast Asia.

The hairy tentacle moth is also called the Australian horror moth and other names that inspire fear and disgust. But why? The moth is really pretty. Its wings are pale brown and white with dark gray stripes in the middle, and it has a black spot on its head. The abdomen is usually red with black spots in a row. The wingspan is about 40 mm.

The issue comes with the way the male attracts a female. Inside his abdomen the male has four coremata, which are glands that emit pheromones. Pheromones are chemicals that other moths can detect, much like smells. When a male is ready to advertise for a mate, he perches on the edge of a leaf or somewhere similar and inflates the coremata so that they unfurl from inside the abdomen, like blowing up a balloon. Sometimes he only extends two of the coremata, sometimes all of them. Either way, the coremata are surprisingly large, sometimes longer than the entire abdomen. They’re dark gray with feathery hairs and they do actually look like hairy tentacles. They’re sometimes called hair pencils, but the term coremata is actually Greek for feather dusters.

If you don’t know what they are, the coremata really do look weird and unpleasant. But the moth is just doing his best to get his pheromones picked up on the breeze so a female will find him. The pheromone also repels other males.

The hairy tentacle moth can only develop his coremata and the pheromones he needs if he eats enough of plants that contain pyrrolizidine alkaloids. These are intensely bitter compounds that are also toxic to many animals. When he’s a caterpillar, the male eats plants that contain these alkaloids and retains them in his body, chemically modifying them later into pheromones, but if he doesn’t eat enough of them, he’s not able to grow coremata either.

Finally, Joel also suggested the hornet moth, which lives in Europe and the Middle East. It’s a moth, but it genuinely looks exactly like a yellow and black striped hornet. It even has clear wings like a hornet or wasp and flies like one too, and it’s about the size of a hornet. Even though it’s harmless, it looks like it would give you a bad sting, which protects it from potential predators who know better than to mess with a hornet. It’s a great example of what’s called Batesian mimicry, but it has one big drawback. The moth lives in some areas where there aren’t any hornets, and in those areas birds and other animals soon learn that those brightly striped insects are yummy and easy to catch.

The female hornet moth lays her eggs in the plants around the base of a tree or on its bark, especially the poplar tree. When the eggs hatch, the larvae spend the next two or three years in and around the tree, mostly around its roots. It eats the wood of the roots, and when it’s ready to pupate it burrows into the tree trunk and spins its cocoon in the burrow. The problem is that it needs the cocoon to be protected inside the tree, not near the entrance of the burrow, but when it emerges from the cocoon it needs to be near the entrance or its newly metamorphosed body will be too large for it to crawl out. To solve the problem, when it’s getting close to emerging, the moth will wriggle around in its cocoon so energetically that it manages to push the pupa up the burrow to the entrance. You can imitate this action by zipping yourself into a sleeping bag and trying to crawl across a room.

For a long time people thought the hornet moth was damaging poplar trees by this behavior, causing them to die. It turns out that the moths aren’t hurting the trees, they’re just more noticeable when poplars are already injured by drought.

There’s also an American hornet moth that lives in some parts of the Midwest and western areas of North America. It’s closely related to the hornet moth of Europe and adults look an awful lot like hornets, but they don’t sting. So the next time you’re about to run from a hornet, take a moment to determine if the hornet is actually a harmless moth. Or at least don’t run, just walk away quickly and safely. Just in case.

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 393: Little Spiders

Thanks to Siya, Zachary, Khalil, and Eilee for their suggestions this week!

The enamel pin Kickstarter goes live on Wednesday, August 14, 2024!!

Further reading:

How spiders breathe under water: Spider’s diving bell performs like gill extracting oxygen from water

Aggressive spiders are quick at making accurate decisions, better at hunting unpredictable preys

Into the Spider-Verse: A young biologist shares her love for eight-legged creatures

A New Genus of Prodidominae Cave Spider from a Paleoburrow and Ferruginous Caves in Brazil

The diving bell spider [photo from this paper]:

Jumping spiders are incredibly cute, even the ones that eat other spiders [photo taken from this excellent site]:

The spoor spider’s web looks like a cloven hoofprint in the sand [photo by JMK – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=39988887]:

Show transcript:

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

I’m excited this week, because on Wednesday my little Kickstarter to fund getting more enamel pins made goes live, and also we’re talking about some weird and fascinating spiders! Thanks to Siya, Zachary, Khalil, and Eilee for their spider suggestions!

A lot of people are afraid of spiders, but don’t worry. All the spiders in this episode are small and completely harmless unless you are a bug. Also, they probably live very far away from you. Personally, I think most spiders are cute.

Let’s start with a spider suggested by Siya, who pointed out that we don’t actually have very many episodes about spiders. Siya suggested we learn about the diving bell spider, a tiny, remarkable animal that lives in parts of Europe and Asia.

The diving bell spider gets its name because it mostly lives underwater but still needs to breathe air, so it brings air with it into the water. A diving bell made by humans is a structure shaped sort of like a big bell that can be lowered straight down into the water on a cable. If the diving bell doesn’t tip to one side or another, the air inside it stays inside and allows a human diver to take breaths without coming to the surface. A diving bell made by spiders is made of silk but is shaped sort of the same, with an entrance at the bottom. The spider builds its bell among water plants to anchor it and keep it hidden. The spider brings air from the surface to replenish the supply of air inside the bell.

The spider does this by surfacing briefly. Its belly and legs are covered with tiny water-repellent hairs, and after surfacing the hairs trap air, so that when it dives back into the water it’s covered with little silvery bubbles. It swims down to its diving bell and rubs the bubbles off its body, which rise into the bell and are trapped there by the closely woven silk. Then it goes back to the surface for more air.

Once the bell is full of air, the spider only needs to replenish the air supply about once a day under normal circumstances. That’s because the bell itself acts as a sort of external gill. It’s able to absorb oxygen from the water quite efficiently, but it still loses volume slowly because nitrogen from the air diffuses into the water. If not for that, the spider probably wouldn’t need to come to the surface at all.

The diving bell is the spider’s home, especially for the female. Unlike most spiders, the female diving bell spider is much smaller than the male and she hunts differently. The male is an active hunter, swimming quickly to catch tiny animals like mosquito larvae, so he’s large and strong but only has a small diving bell. The female spends most of her time in her diving bell and only swims out to catch animals that come too close, or occasionally to replenish the air in her bell.

When the spider leaves its diving bell to hunt, air bubbles remain trapped on its abdomen, which allows it to breathe while it’s hunting too. Then it can dart back to its bell to get more air or hide if it needs to.

When a male finds a female, he will build his diving bell near hers. If she doesn’t object, he’ll build a little tunnel between the two bells so he can visit her more easily. The pair will mate in the female’s bell and she either attaches her egg sac to the inside wall of her bell or will build a little addition onto her bell that acts as a nursery.

The diving bell spider is gray or black in color and even a big male only grows about 15 mm long, head and body size together. His legs are longer. In the water the spiders appear silver because of the bubbles attached to their bodies.

The spider used to be common throughout much of Asia and Europe, but its numbers are in decline due to pollution and habitat loss, since it needs slow-moving streams, ponds, marshes, and other clean freshwater with aquatic plants to survive. It will bite if it feels threatened and some people claim that its bite is painful and leads to symptoms like fever, but there’s not a lot of evidence for the bite being dangerous or even all that painful to humans.

Next, Zachary suggested the Portia spider, and pointed out that it demonstrates “uniquely intelligent hunting.” If it weren’t such a tiny spider, it might be scary because it’s so smart. Fortunately for humans, not only is it even smaller than the diving bell spider, with even a big female no more than 10 mm long counting her head and body together, it’s a spider that eats other spiders.

There are 17 species of portia spider currently known, living in parts of Africa, Asia, Australia, and a lot of islands in southeast Asia. It’s a type of jumping spider and can jump as much as 6 inches, or 15 cm, from a complete standstill. It’s mostly brown with mottled darker and lighter markings that make it look like a bit of dead leaf when it’s standing still. It also has flaps on its legs that help it look less like a spider too.

Looking like a bit of dead leaf helps the Portia spider keep from being eaten by birds and frogs, but it also helps it when hunting prey spiders. Unlike almost all other spiders, the portia spider can travel on the webs of pretty much any species of spider without getting stuck. It will creep into another spider’s web and sneak up on it very slowly, or pretend to be a stuck insect to lure it closer. Most spiders don’t see very well, so they don’t identify the portia as a predatory spider. They either think it’s just a leaf stuck in its web or an insect, until it’s too late.

The portia spider will try many different ways to catch a spider. If one doesn’t work it will use another method, and will continue to try new methods and combinations of methods until it outsmarts the prey spider and can jump on it. The methods it uses can be incredibly complex and often require the portia spider to move away from the prey spider or even out of view of it, but it can remember exactly where the prey spider is and what it wants to do to approach it. Remember, this is an animal about the size of one of your fingernails. It has a teeny brain!

In captive studies, portia spiders are observed to be more or less aggressive depending on the individual. The more aggressive spiders tend to do a better job hunting prey with unpredictable behaviors, while the less aggressive spiders are more patient.

When the portia spider walks, it does so arrhythmically, which helps it imitate a dead leaf being moved by the wind. Some spiders are so nervous of portia spiders that if they sense an arrhythmic movement on their web, even if it’s not a portia spider, they’ll run and hide. For that matter, the portia spider will take advantage of wind and other natural occurrences to get closer to their prey.

In addition to active hunting, female portia spiders will also build funnel webs to catch insects. You know, kind of a side hustle. Any portia spider will spin a simple web to hide behind to rest. Portia spiders are also social, sharing food and even living together.

When the male portia spider wants to find a mate, he spins a little web near a female’s web and shakes his legs to attract the female. If she likes him, she’ll drum on his web to let him know. However, in most species, mating is a death sentence for the male. Remember how last week we talked about the praying mantis and how sometimes the female will actually eat the male after or even during mating? Well, that’s true for most species of portia spider too. In some species the female almost always eats the male. He gets to pass his genes along to the next generation, and she gets a good meal to help her grow healthy eggs.

Next, Leo’s friend Khalil suggested the wandering spider. This is the name given to a big family of spiders that live throughout much of the world. Most of them are quite large and look like tarantulas, especially the Brazilian wandering spider, also called the banana spider. It can have a head and body length of two inches, or about 5 cm, but a legspan of up to 7 inches, or 18 cm. That’s a lot of spider, and this week we’re talking about small spiders, but let’s take a quick detour and find out if the banana spider really is sometimes found in bunches of bananas sold in stores.

The banana spider lives in Brazil and other parts of northern South America and Central America, and that’s where a lot of the world’s bananas are grown. I couldn’t find any good estimates of how many bananas are exported every year, but the United States is the biggest importer of bananas. I’m going to switch completely to imperial measurements for a moment because the amounts I’m about to talk about make no logical sense anyway. About four bananas add up to one pound of weight, and 2000 pounds make up one ton. That means one ton of bananas is approximately 8,000 bananas. In 2023, over 5 million tons of bananas were imported to the United States. That is at least 40 billion bananas!

In comparison, no one seems to be tracking how many spiders are found hiding in banana bunches, but one paper from 2014 documented that of 135 spiders submitted to the scientists for study as having been found in all international shipments, of bananas and everything else, only seven were actually banana spiders. The rest were other kinds of spider, most of them completely harmless. When one is found it gets into the news because it’s so rare.

Spiders don’t live inside the banana peel anyway, and they don’t eat bananas. It’s just that bunches of bananas make good hiding places, and the spiders don’t know that people are going to chop the whole bunch down without even noticing a hidden spider. By the time the bananas get to the store, the big bunches have been cut up into little bunches of a few bananas each, which isn’t a great hiding space for a big spider. So your bananas are safe.

Anyway, the smallest wandering spider is probably in the genus Acanthonoctenus, which are native to Central and South America. A big female only grows about 15 mm long, head and body measured together, although her legspan is much larger. There are other wandering spiders with about the same body size in various genera. The problem is, there are hundreds of known species of wandering spider and probably a lot more that haven’t been discovered yet, but not a lot of people are studying them. We don’t know a whole lot about the smallest species because they’re harder to find and therefore harder to study. Many species have only ever had a single specimen collected. So if you want to become an arachnologist, you might look into wandering spiders for your specialization. Many of them are absolutely gorgeous, with striped legs and bright colors.

Like some other spiders, many Acanthonoctenus spiders will hide on a leaf or tree trunk by lying flat and stretching four of its legs out in front of it and the other four legs behind it. This makes it less spider shaped when a bird or lizard is looking around trying to find a snack.

Next, Eilee suggested the spoor spider, the name for Seothyra, a genus of spiders that live in sandy areas in southern Africa. Females grow up to 15 mm long, head and body together, while males grow up to 12 mm long and are usually considerably smaller than the females. The female can be brown, gray, or tan and may have stripes on her abdomen, while the male is more brightly colored. He can be yellow and black with a rusty-red head, sometimes with white spots on his abdomen.

The male spends most of his time running around finding food, and since he looks a lot like a type of wasp called the velvet ant, he’s in less danger than you’d think considering he’s active during the day. The female spends almost all of her life in an elaborate web that she builds into the sand.

The female excavates a burrow in the sand that can be as much as 6 inches deep, or 15 cm, lined with silk to keep it from collapsing. She gets sand out of the burrow as she constructs it by spinning little silk bags around the sand to carry it out. She leaves the bags of sand around the entrance, and once the burrow is finished, she incorporates the sandbags into the web itself. She spins web sheets and mixes them with sand to make mats around the burrow’s opening, which is hidden, and the spider can lift the web sheets to go in and out. Ideally she stays in the same burrow her whole life, repairing it as needed, because while it’s not an especially big web, it takes her a lot of energy to make.

The female puts sticky strands of silk around the edges of the web, then retreats to the underside of the web sheet or into the burrow if it’s too hot. When an insect gets stuck on the silk, she darts out and kills it, then takes it into her burrow to eat. Mostly she eats ants.

The name spoor spider, also called buck spoor spider, comes from the shape of the female’s web. In most species, the web sheet has two sides in a shallow depression in the sand. Since the web is also covered with and incorporates sand to hide it, the little depression with a rounded double shape at the bottom looks an awful lot like the footprint of an animal with a cloven hoof. The word “spoor” is a term indicating an animal’s track.

The spoor spider female only produces one egg sac in her life, and takes care of it in her burrow until the babies hatch. Then she takes care of the babies by gradually liquefying her own internal organs and regurgitating the liquid so the babies can eat it. When all her organs are gone she dies, naturally, and the babies eat the remainder of her body before venturing out into the world on their own.

Fossilized web sheets very similar to the modern spoor spider’s web have been found dating back 16 million years. Most spiderwebs can’t fossilize, but most spiderwebs aren’t built partly out of sand.

Finally, let’s finish up with a newly discovered spider from South America. I learned about it from Zeke Darwin, a science teacher who makes really interesting videos on TikTok. The spider has been described as a new species, named Paleotoca, and was discovered in Brazil. We know very little about it so far so I don’t have much information to share, but it’s so interesting that I just had to include it.

Paleotoca is pale yellow, although its abdomen has very little pigmentation, and its head and body together measure barely 2 mm. It doesn’t have eyes. You might be able to guess where it lives from its lack of eyes and lack of pigment in its body, but I bet I’m going to surprise you anyway. Paleotoca does live in caves, but technically these caves are burrows. It’s just that the burrows where it lives are extremely large, dug into the sides of hills thousands of years ago by giant ground sloths before they went extinct.

Luckily for the spider, there are also some natural caves in the area and at least one of the spiders has been found living in one. So little Paleotoca isn’t in danger of going extinct just because the burrow-builders are gone.

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 389: Updates 7 and the Lava Bear

It’s our annual updates episode! Thanks to Kelsey and Torin for the extra information about ultraviolet light, and thanks to Caleb for suggesting we learn more about the dingo!

Further reading:

At Least 125 Species of Mammals Glow under Ultraviolet Light, New Study Reveals

DNA has revealed the origin of this giant ‘mystery’ gecko

Bootlace Worm: Earth’s Longest Animal Produces Powerful Toxin

Non-stop flight: 4,200 km transatlantic flight of the Painted Lady butterfly mapped

Gigantopithecus Went Extinct between 295,000 and 215,000 Years Ago, New Study Says

First-Ever Terror Bird Footprints Discovered

Last surviving woolly mammoths were inbred but not doomed to extinction

Australian Dingoes Are Early Offshoot of Modern Breed Dogs, Study Shows

A (badly) stuffed lava bear:

Show transcript:

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

This week we have our annual updates episode, and we’ll also learn about a mystery animal called the lava bear! As usual, a reminder that I don’t try to update everything we’ve ever talked about. That would be impossible. I just pick new information that is especially interesting.

After our episode about animals and ultraviolet light, I got a great email from Kelsey and Torin with some information I didn’t know. I got permission to quote the email, which I think you’ll find really interesting too:

You said humans can’t see UV light, which is true, however humans can detect UV light via neuropsin (a non-visual photoreceptor in the retina). These detectors allow the body to be signaled that it’s time to do things like make sex-steroid hormones, neurotransmitters, etc. (Spending too much time indoors results in non-optimal hormone levels, lowered neurotransmitter production, etc.)

Humans also have melanopsin detectors in the retina and skin. Melanopsin detectors respond to blue light. Artificial light (LEDs, flourescents, etc) after dark entering the eye or shining on the skin is sensed by these proteins as mid-day daylight. This results in an immediate drop in melatonin production when it should be increasing getting closer to bedtime.”

And that’s why you shouldn’t look at your phone at night, which I am super bad about doing.

Our first update is related to ultraviolet light. A study published in October of 2023 examined hundreds of mammals to see if any part of their bodies glowed in ultraviolet light, called fluorescence. More than 125 of them did! It was more common in nocturnal animals that lived on land or in trees, and light-colored fur and skin was more likely to fluoresce than darker fur or skin. The white stripes of a mountain zebra, for example, fluoresce while the black stripes don’t.

The study was only carried out on animals that were already dead, many of them taxidermied. To rule out that the fluorescence had something to do with chemicals used in taxidermy, they also tested specimens that had been flash-frozen after dying, and the results were the same. The study concluded that ultraviolet fluorescence is actually really common in mammals, we just didn’t know because we can’t see it. The glow is typically faint and may appear pink, green, or blue. Some other animals that fluoresce include bats, cats, flying squirrels, wombats, koalas, Tasmanian devils, polar bears, armadillos, red foxes, and even the dwarf spinner dolphin.

In episode 20 we talked about Delcourt’s giant gecko, which is only known from a single museum specimen donated in the 19th century. In 1979 a herpetologist named Alain Delcourt, working in the Marseilles Natural History Museum in France, noticed a big taxidermied lizard in storage and wondered what it was. It wasn’t labeled and he didn’t recognize it, surprising since it was the biggest gecko he’d ever seen—two feet long, or about 60 cm. He sent photos to several reptile experts and they didn’t know what it was either. Finally the specimen was examined and in 1986 it was described as a new species.

No one knew anything about the stuffed specimen, including where it was caught. At first researchers thought it might be from New Caledonia since a lot of the museum’s other specimens were collected from the Pacific Islands. None of the specimens donated between 1833 and 1869 had any documentation, so it seemed probable the giant gecko was donated during that time and probably collected not long before. More recently there was speculation that it was actually from New Zealand, since it matched Maori lore about a big lizard called the kawekaweau.

In June of 2023, Delcourt’s gecko was finally genetically tested and determined to belong to a group of geckos from New Caledonia, an archipelago of islands east of Australia. Many of its close relations are large, although not as large as it is. It’s now been placed into its own genus.

Of course, this means that Delcourt’s gecko isn’t the identity of the kawekaweau, since it isn’t very closely related to the geckos of New Zealand, but it might mean the gecko still survives in remote parts of New Caledonia. It was probably nocturnal and lived in trees, hunting birds, lizards, and other small animals.

We talked about some really big worms in episode 289, but somehow I missed the longest worm of all. It’s called the bootlace worm and is a type of ribbon worm that lives off the coast of Norway, Denmark, Sweden, and Britain, and it’s one of the longest animals alive. The longest worm we talked about in episode 289 was an African giant earthworm, and one was measured in 1967 as 21 feet long, or 6.7 meters. The bootlace worm is only 5 to 10 mm wide, but it routinely grows between 15 and 50 feet long, or 5 to 15 meters, with one dead specimen that washed ashore in Scotland in 1864 measured as over 180 feet long, or 55 meters.

When it feels threatened, the bootlace worm releases thick mucus. The mucus smells bad to humans but it’s not toxic to us or other mammals, but a recent study revealed that it contains toxins that can kill crustaceans and even some insects.

We talked about the painted lady butterfly in episode 203, which was about insect migrations. The painted lady is a small, pretty butterfly that lives throughout much of the world, even the Arctic, but not South America for some reason. Some populations stay put year-round, but some migrate long distances. One population winters in tropical Africa and travels as far as the Arctic Circle during summer, a distance of 4,500 miles, or 7,200 km, which takes six generations. The butterflies who travel back to Africa fly at high altitude, unlike monarch butterflies that fly quite low to the ground most of the time. Unlike the monarch, painted ladies don’t always migrate every year.

In October of 2013, a researcher in a small country in South America called French Guiana found some painted lady butterflies on the beach. Gerard Talavera was visiting from Spain when he noticed the butterflies, and while he recognized them immediately, he knew they weren’t found in South America. But here they were! There were maybe a few dozen of them and he noticed that they all looked pretty raggedy, as though they’d flown a long way. He captured several to examine more closely.

A genetic study determined that the butterflies weren’t from North America but belonged to the groups found in Africa and Europe. The question was how did they get to South America? Talavera teamed up with scientists from lots of different disciplines to figure out the mystery. Their findings were only published last month, in June 2024.

The butterflies most likely rode a well-known wind current called the Saharan air layer, which blows enough dust from the Sahara to South America that it has an impact on the Amazon River basin. The trip from Africa to South America would have taken the butterflies 5 to 8 days, and they would have been able to glide most of the time, thus conserving energy. Until this study, no one realized the Saharan air layer could transport insects.

We talked about the giant great ape relation Gigantopithecus in episode 348, and only a few months later a new study found that it went extinct 100,000 years earlier than scientists had thought. The study tested the age of the cave soils where Gigantopithecus teeth have been discovered, to see how old it was, and tested the teeth again too. As we talked about in episode 348, Gigantopithecus ate fruit and other plant material, and because it was so big it would have needed a lot of it. It lived in thick forests, but as the overall climate changed around 700,000 years ago, the forest environment changed too. Other great apes living in Asia at the time were able to adapt to these changes, but Gigantopithecus couldn’t find enough food to sustain its population. It went extinct between 295,000 and 215,000 years ago according to the new study, which is actually later than I had in episode 348, where I wrote that it went extinct 350,000 years ago. Where did I get my information? I do not know.

The first footprints of a terror bird were discovered recently in Argentina, dating to 8 million years ago. We talked about terror birds in episode 202. The footprints were made by a medium-sized bird that was walking across a mudflat, and the track is beautifully preserved, which allows scientists to determine lots of new information, such as how fast the bird could run, how its toes would have helped it run or catch prey, and how heavy the bird was. We don’t know what species of terror bird made the tracks, but we know it was a terror bird.

We talked about the extinction of the mammoth in episode 256, especially the last population of mammoths to survive. They lived on Wrangel Island, a mountainous island in the Arctic Ocean off the coast of western Siberia, which was cut off from the mainland about 10,000 years ago when ocean levels rose. Mammoths survived on the island until about 4,000 years ago, which is several hundred years after the Great Pyramid of Giza was built. It’s kind of weird to imagine ancient Egyptians building pyramids, and at the same time, mammoths were quietly living on Wrangel Island, and the Egyptians had no idea what mammoths were. And vice versa.

A 2017 genetic study stated that the last surviving mammoths were highly inbred and prone to multiple genetic issues as a result. But a study released in June of 2024 reevaluated the population’s genetic diversity and made a much different determination. The population did show inbreeding and low genetic diversity, but not to an extent that it would have affected the individuals’ health. The population was stable and healthy right to the end.

In that case, why did the last mammoths go extinct? Humans arrived on the island for the first time around 1700 BCE, but we don’t know if they encountered mammoths or, if they did, if they killed any. There’s no evidence either way. All we know is that whatever happened, it must have been widespread and cataclysmic to kill all several hundred of the mammoths on Wrangel Island.

We talked about the dingo in episode 232, about animals that are only semi-domesticated. That episode came out in 2021, and last year Caleb suggested we learn more about the dingo. I found a really interesting 2022 study that re-evaluated the dingo’s genome and made some interesting discoveries.

The dingo was probably brought to Australia by humans somewhere between 3,500 and 8,500 years ago, and after the thylacine was driven to extinction in the early 20th century, it became the continent’s apex predator. Genetic studies in the past have shown that it’s most closely related to the New Guinea singing dog, but the 2022 study compared the dingo’s genome to that of five modern dog breeds, the oldest known dog breed, the basenji, and the Greenland wolf.

The results show that the dingo is genetically in between wolves and dogs, an intermediary that shows us what the dog’s journey to domestication may have looked like. The study also discovered something else interesting. Domestic dogs have multiple copies of a gene that controls digestion, which allows them to eat a wide variety of foods. The dingo only has one copy of that gene, which means it can’t digest a lot of foods that other dogs can. Remember, the dingo has spent thousands of years adapting to eat the native animals of Australia. When white settlers arrived, they would kill dingoes because they thought their livestock was in danger from them. The study shows that the dingo has little to no interest in livestock because it would have trouble digesting, for instance, a lamb or calf. The animals most likely to be hurting livestock are domestic dogs that are allowed to run wild.

We’ll finish with a mystery animal called the lava bear. In the early 20th century, starting in 1917, a strange type of bear kept being seen in Oregon in the United States. Its fur was light brown like a grizzly bear’s, but otherwise it looked like a black bear—except for its size, which was very small. The largest was only about 18 inches tall at the back, or 46 cm, and it only weighed about 35 pounds, or 16 kg. That’s the size of an ordinary dog, not even a big dog. Ordinarily, a black bear can stand 3 feet tall at the back, or about 91 cm, and weighs around 175 pounds, or 79 kg, and a big male can be twice that weight and much taller.

The small bear was seen in desert, especially around old lava beds, which is where it gets its name. A shepherd shot one in 1917, thinking it was a bear cub, and when he retrieved the body he was surprised to find it was an adult. He had it taxidermied and photographs of it were published in the newspapers and a hunting magazine, which brought more hunters to the area.

People speculated that the animal might be an unknown species of bear, possibly related to the grizzly or black bear, and maybe even a new species of sun bear, a small bear native to Asia.

Over the next 17 years, many lava bears were killed by hunters and several were captured for exhibition. When scientists finally got a chance to examine one, they discovered that it was just a black bear. Its small size was due to malnutrition, since it lived in a harsh environment without a lot of food, and its light-colored fur was well within the range of fur color for an American black bear. Lava bears are still occasionally sited in the area around Fossil Lake.

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 387: The Link Between Fossils and Folklore

Thanks to Richard from NC for inspiring this episode!

Further reading:

Paleontologists Debunk Popular Claim that Protoceratops Fossils Inspired Legend of Griffin

The Fossil Dragons of Lake Lucerne, Switzerland

The Lindworm statue:

A woolly rhinoceros skull:

A golden collar dated to the 4th century BCE, made by Greek artisans for the Scythians, discovered in Ukraine. The bottom row of figures shows griffins attacking horses:

The Cyclops and a (damaged, polished) elephant skull:

A camahueto statue [photo by De Rjcastillo – Trabajo propio, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=145434346]:

Show transcript:

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

This week we’re going to learn about the link between fossils and folklore, a topic inspired by a conversation I had with Richard from North Carolina.

We know that stories about monsters were sometimes inspired by fossils, and we even have an example from episode 53. That was way back in 2018, so let’s talk about it again.

In Klagenfurt in Austria there’s a statue of a dragon, called the lindorm or lindwurm, that was erected in 1593 to commemorate a local story. The story goes that a dragon lived near the lake and on foggy days would leap out of the fog and attack people. Sometimes people could hear its roaring over the noise of the river. Finally the duke had a tower built and filled it with brave knights. They fastened a barbed chain to a collar on a bull, and when the dragon came and swallowed the bull, the chain caught in its throat and tethered it to the tower. The knights came out and killed the dragon.

The original story probably dates to around the 12th century, but it was given new life in 1335 when a skull was found in a local gravel pit. It was clearly a dragon skull and in fact it’s still on display in a local museum. The monument’s artist based the shape of the dragon’s head on the skull. In 1935 the skull was identified as that of a woolly rhinoceros.

In 1989 a folklorist proposed that the legend of the griffin was inspired by protoceratops fossils. The griffin is a mythological creature that’s been depicted in art, writing, and folklore dating back at least 5,000 years, with early variations on the monster dating back as much as 8,000 years. The griffin these days is depicted as a mixture of a lion and an eagle. It has an eagle’s head, wings, and front legs, and it often has long ears, while the rest of its body is that of a lion.

The griffin isn’t a real animal and never was. It has six limbs, for one thing, four legs and two wings, and it also has a mixture of mammal and bird traits. I can confirm that it’s a lot of fun to draw, though, and lots of great stories and books have been written about it in modern times. Ancient depictions of a griffin-like monster have been found throughout much of eastern Europe, the Middle East, the Mediterranean, northern Africa, and central Asia. Much of what we know about the griffin legend comes from ancient Greek and Roman stories, but they in turn got at least some of their stories from ancient Scythia. That’s important for the hypothesis that the griffin legend was inspired by protoceratops fossils.

Protoceratops lived between 75 and 71 million years ago and its fossils have been found in parts of China and Mongolia. It was a ceratopsian but it didn’t belong to the family Ceratopsidae, which includes Triceratops. It grew up to about 8 feet long, or 2.5 meters, with a big skull and a neck frill, but while that sounds big, it actually was on the small size for a ceratopsian. At most it would have barely stood waist-high to an average human, so while it was heavy and compact, it was probably smaller, if not lighter, than a modern lion. It ate plants and while it had teeth, it also had a beak, sort of like a turtle’s beak.

Folklorist Adrienne Mayor published a number of papers and a book in the 1990s discussing the links between protoceratops fossils and the griffin legend. The fossils are fairly common in parts of Mongolia and China, and Mayor pointed out that the beak combined with four legs would have suggested a four-footed animal with a bird’s head. She suggested that the head frill might have been interpreted as wings.

As for the Scythians, which we talked about a few minutes ago, they were a nomadic people who ruled much of west and central Asia and part of eastern Europe up to about 300 BCE. They were skilled in metalworking and loved gold, so even though they didn’t have a system of writing, we have some of their metal artifacts found by archaeologists. The Scythians were so important to the ancient world that we know a lot about them from other cultures, especially the ancient Greeks, Persians, and Assyrians.

We know the griffin appeared in Scythian mythology because it’s depicted on some decorative metal items. We also have ancient stories about griffins loving gold and either battling people to steal gold, or mining gold that people stole from them, or some other variation. Scythians had elaborate trade routes that connected Asia and Europe, and as I mentioned, they were hugely influential. I mean, we’re still telling versions of monster stories that the Scythians probably came up with originally.

Mayor suggested that the Scythians found protoceratops fossils while prospecting for gold, thought they were the bones of the monster we now call a griffin, and spread stories about them throughout Eurasia. It sounds plausible, so much so that no one really investigated the story until recently.

Just last week as this episode goes live, a new study has been published by a team of paleontologists about the griffin-protoceratops connection. They worked with historians and archaeologists to determine when and where (and if) the Scythians might have discovered protoceratops fossils.

It turns out that they probably wouldn’t have, certainly not while prospecting or mining gold. Gold has never been found anywhere near protoceratops fossils, and in fact the known gold deposits in central Asia occur hundreds of kilometers away from the fossils found so far. Not only that, it would be very rare to find more than a little bit of fossilized bone sticking out of the rock in most cases.

The spread of the griffin in art doesn’t seem to have begun in central Asia, for that matter, and even the earliest artwork doesn’t seem to be very protoceratops-like. The head isn’t huge in comparison to the body, for instance. Early griffins were commonly depicted as lions with an eagle’s head, but sometimes they were depicted as eagles with a lion’s head.

That doesn’t mean that protoceratops fossils didn’t influence griffin mythology at some point, just that it didn’t seem to happen the way Mayor claimed it did.

Another common connection between a fossil and a mythical monster is likewise just speculation. The skulls of elephants and their ancestors have a big opening in the front that looks like a giant eyesocket, but which is where the trunk was located. The eyes are much smaller and more on the sides of the head, and the skull itself does somewhat resemble a really big human skull. The Cyclops, or Cyclopes, was a giant from ancient Greek myth with one eye in the middle of its face instead of the usual two eyes. Is there really a connection between some kind of elephant skull and the Cyclops?

The connection was first suggested in 1914 by a paleontologist named Othenio Abel, who suggested that skulls from dwarf elephants had inspired the myth. Before about 500 BCE, the ancient Greeks didn’t know what elephants were, and the dwarf elephants that once lived in the area went extinct about 20,000 years ago. Sicily and Malta in particular had been home to various species of dwarf elephant for half a million years, so it’s possible that elephant remains were occasionally discovered in the area. Our griffin-protoceratops friend Adrienne Mayor agrees, but there’s no proof either way of this happening.

Stories of dragons living on Mount Pilatus in Switzerland may have been inspired by the pterosaur fossils that are frequently found in the area. In 1649 a man named Christopher Schorer reported seeing a fiery dragon fly from a cave in the side of Mount Pilatus to another mountain, although he admitted that at first he thought it was a meteor. It was probably a meteor, in fact, but he convinced himself it had to be a dragon because they were known to live on the mountain. A so-called dragon skeleton found near the mountain in 1602 had reportedly been crushed flat by rocks during an earthquake, but once science caught up with the finding, it was determined to be a fossilized pterodactyl.

In many parts of the world, especially China, fossilized bones are called dragon bones, but the dragon as a mythological creature probably came first. This is probably the case for a lot of folklore monsters and animals. The story came first, and once fossils were found in the area, they were seen as proof that the story was true.

In Patagonia in South America, there’s a Chilote legend of a monster called the camahueto. When it’s grown it lives in the ocean, but it starts out life living underground. Eventually it picks a stormy night, and it emerges from the ground and rushes toward the ocean, destroying everything in its path. Its single horn may gouge a channel in the ground for a new stream to form, or it may actually live in a river as a young animal and migrate to the ocean as an adult.

An animal named Trigodon once lived in Patagonia. It was a notoungulate, part of an extinct order of hoofed animals that lived throughout South America. It was probably most closely related to rhinoceroses, horses, and other odd-toed ungulates, but it and its relatives are completely extinct with no living descendants.

Trigodon was big and heavy, probably resembling a rhinoceros in many ways, and that includes having a single short horn on its head. On its forehead, in fact, pointing straight forward. It probably wasn’t a true horn but it was a protuberance of the skull. We don’t know if it was covered with skin and hair like an ossicone, a keratin sheath like a true horn, or if it was more like a rhinoceros horn. It might have been something completely different that’s currently unknown among living animals.

Trigodon went extinct around 4 million years ago, as far as we know, but other notoungulates only went extinct around 12,000 years ago. We don’t know very much about most of them, but we do know that at least one other species had a forehead horn like Trigodon’s. It’s always possible that a rhinoceros-like one-horned animal was still alive when humans first settled Patagonia, and that it was so big and scary it inspired stories about the monster Camahueto, a bull with a single horn on its forehead.

Then again, consider the story about the camahueto. It lives underground or in rivers when it’s young, and travels to the sea only during a storm. That might just be a story used to explain earthquakes that open fissures in the ground, and other natural phenomena. Then again, it might have been inspired by fossilized trigodon skulls that are washed out of the ground by torrential rain or rivers. That’s just my theory, though, but it’s fun to speculate.

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!