Episode 406: Some Turtles and a Friend

Thanks to Riley and Dean, Elizabeth, and Leo for their suggestions this week!

Further reading:

Groundbreaking study reveals extensive leatherback turtle activity along U.S. coastline

A bearded dragon:

The tiny bog turtle:

The massive leatherback sea turtle:

The beautiful hawksbill turtle [photo by U.S. Fish and Wildlife Service]:

Show transcript:

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

This week we’re going to learn about some reptiles suggested by four different listeners: Riley and Dean, Elizabeth, and Leo.

We’ll start with the brothers Riley and Dean. Dean wants to learn more about the bearded dragon, and that may have something to do with a certain pet bearded dragon named Kippley.

“Bearded dragon” is the name given to any of eight species of lizard in the genus Pogona, also referred to as beardies. They’re native to Australia and eat plants and small animals like worms and insects. They can grow about two feet long, or 60 cm, including the tail, but some species are half that length. Females are a little smaller than males on average.

The bearded dragon gets its name because its throat is covered with pointy scales that most of the time aren’t very noticeable, but if the lizard is upset or just wants to impress another bearded dragon, it will suck air into its lungs so that its skin tightens and the spiky scales under its throat and on the rest of its body stick out. They’re not very sharp but they look impressive. Since the bearded dragon can also change color to some degree the same way a chameleon can, when it inflates its throat to show off its beard, the beard will often darken in color to be more noticeable. Both males and females have this pointy “beard.”

Bearded dragons that are sold as pets these days are more varied and brighter in color than their wild counterparts, although wild beardies can be brown, reddish-brown, yellow, orange, and even white. Australia made it illegal to catch and sell bearded dragons as pets in the late 20th century, but there were already lots of them outside of Australia by then. Pet bearded dragons are mainly descended from lizards exported during the 1970s, which means they’re quite domesticated these days and make good pets.

Like some other reptiles and amphibians, the bearded dragon has a third eye in the middle of its forehead. If you have a pet beardie and are about to say, “no way, there is definitely not a third eye anywhere, I would have noticed,” the eye doesn’t look like an eye. It’s tiny and is basically just a photoreceptor that can sense light and dark. Technically it’s called a parietal eye and researchers think it helps with thermoregulation.

Next, Riley wants to learn about turtles, AKA turbles, and especially wants everyone to know the difference between a tortoise and a turtle. It turns out that while many turtles are just fine living on land, they’re often more adapted to life in the water. Turtles have a more streamlined shell and often flipper-like legs or webbed toes. Tortoises only live on land and as a result they have shells that are more dome-shaped, and they have large, strong legs that resemble those of a tiny elephant.

You can’t always go by an animal’s common name to determine if it’s a tortoise or a turtle, but it’s also not always clear whether an animal is a tortoise or a turtle at first glance. Take the eastern box turtle, for instance, which is common in the eastern United States. It has a domed carapace, or shell, but it’s still a turtle, not a tortoise. And, I’m happy to say, it can swim quite well. This is a relief to find out because when I was about six years old, my mom visited someone who had kids a little older than me. I didn’t know them but they were nice and showed me the swampy area near their house. At one point one of the older boys found a box turtle, took it over to a little bridge over a pond, and dropped it in the water. I screamed, and he was absolutely shocked. He said he thought box turtles belonged in the water and he was helping it, but I thought they couldn’t swim and he’d just killed the poor turtle. I have continued to think he’d killed the poor turtle until just now, when I learned they can swim, and I can’t even tell you how relieved I am. Anyway, eastern box turtles have a domed shell, yes, and stumpy club-like front legs, but their hind legs are less like elephant legs than regular turtle legs. Since box turtles can live to be 100 years old, it’s possible that that one is alive and well even now.

Riley also wants everyone to know not to take a turtle from the woods, which is a very good rule to live by. In fact, it’s important not to take any wild animals from the woods no matter how cute they are. To continue our example, eastern box turtles have small territories that they defend from other box turtles. If you take the turtle out of its territory even for just a few days, when you return it to the woods, another turtle may have already taken over and will chase it away. Turtles don’t travel very fast and are vulnerable to being hit by cars and eaten by lots of different predators, so without a safe territory where it can hide and find food, it can die very quickly.

One of the turtles Leo suggested we learn about was the bog turtle. It’s the smallest turtle in North America, with a carapace barely four inches long, or 10 cm. It lives in a few parts of the eastern United States, and likes marshy areas with slightly acidic water. It spends a lot of time in the water, but also plenty of time on land. It eats worms, slugs, snails, water plants, berries, insects, and even small frogs when it can catch them.

The bog turtle is so small that pretty much anything big enough to swallow it will eat it. Its main defense is to bury itself in soft mud and hide. It’s almost completely black or dark gray in color, but it does have a bright orange spot on each side of its neck.

The bog turtle is critically endangered due to habitat loss, pollution, and poaching for the illegal pet trade. Conservationists are working to improve its habitat, and in the meantime some zoos and aquariums are helping with a captive breeding program. Since a bog turtle isn’t old enough to lay eggs until it’s at least 8 years old, the species as a whole reproduces slowly.

Leo also suggested hawksbill and leatherback turtles, and Elizabeth wants to learn about sea turtles in general. We talked about sea turtles way back in episode 75, so it’s definitely time to revisit the topic.

Seven species of sea turtle are alive today, and you can tell they’re turtles and not tortoises because they have streamlined shells and flippers instead of feet. They migrate long distances to lay eggs, thousands of miles for some species and populations, and usually return to the same beach where they were hatched. Female sea turtles come ashore to lay their eggs in sand, but the males of most species never come ashore. The exception is the green sea turtle, which sometimes comes ashore just to bask in the sun. Once the babies hatch, they head to the sea and take off, swimming far past the continental shelf where there are fewer predators. They live around rafts of floating seaweed call sargassum, which protects them and attracts the tiny prey they eat.

Six of the extant sea turtles are relatively small. Not small compared to regular turtles, small compared to the seventh living sea turtle, the leatherback. It’s much bigger than the others and not very closely related to them. It can grow some nine feet long, or 3 meters, and instead of having a hard shell like other sea turtles, its carapace is covered with tough, leathery skin studded with tiny osteoderms. Seven raised ridges on the carapace run from head to tail and make the turtle more stable in the water, a good thing because leatherbacks migrate thousands of miles every year. Not only is the leatherback the biggest and heaviest turtle alive today by far, it’s the heaviest living reptile that isn’t a crocodile. It has huge front flippers, is much more streamlined even than other sea turtles, and has a number of adaptations to life in the open ocean.

The leatherback lives throughout the world, from warm tropical oceans up into the Arctic Circle. It mostly eats jellyfish, so it goes where the jellyfish go, which is everywhere. It also eats other soft-bodied animals like squid. To help it swallow slippery, soft food when it doesn’t have the crushing plates that other sea turtles have, the leatherback’s throat is full of backwards-pointing spines. What goes down will not come back up, which is great when the turtle swallows a jellyfish, not so great when it swallows a plastic bag. It’s endangered due to pollution, accidental drowning when it gets caught in fishing nets, and habitat loss of its nesting beaches.

The hawksbill, or hawkbill sea turtle grows to a much more reasonable size, around three feet long, or 90 cm, and mostly lives around tropical reefs. It has a more pointed, hooked beak than other sea turtles, sort of like a hawk, which gives it its name. You might think it eats fish with a beak like that, but it mostly eats jellyfish and sea sponges. It especially likes the sea sponges, some of which are lethally toxic to most other animals. It also doesn’t have a problem eating even extremely stingy jellies and jelly-like animals like the Portuguese man-o-war. The hawkbill’s head is armored so the stings don’t bother it, although it does close its eyes while it chomps down on jellies. Its meat can be toxic due to the toxins it ingests. People used to kill hawksbill sea turtles for their multicolored shells, but these days it’s a protected species like all sea turtles.

The hawksbill is also biofluorescent! Researchers only found this out by accident in 2015, when a team studying biofluorescent animals in the Solomon Islands saw and filmed a hawksbill glowing like a UFO with neon green and red light. So you never know what other secrets sea turtles might be hiding.

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 403: Predator X

Thanks to Eesa for suggesting this week’s topic, the pliosaur Predator X!

Further reading:

Predator X / Pliosaurus funkei [you can find lots of interesting pictures here, some artwork and some skeletal diagrams]

Kronosaurus had a big skull with big teeth:

Show transcript:

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

We’re one week closer to Halloween, and that means the monsters are getting more monster-y, at least in name, although I wouldn’t want to meet this one in person. It’s referred to as Predator X, and thanks to Eesa for suggesting it!

Fortunately for everyone who likes to swim and boat in the ocean, Predator X has been extinct for around 145 million years. It’s a type of marine reptile called a pliosaur, Pliosaurus funkei, but there was nothing funky about it. It was huge, fast, and incredibly strong. Also, the funky part of the name comes from the couple who originally discovered the first specimen, who had the last name of Funke.

We only have two Predator X specimens right now, both of them found in the same rock formation from a Norwegian island. The remains were first discovered in 2004 but the process of recovering them took many years. Because winters in Norway are very cold, the exposed rocks were subject to freezing temperatures that had broken a lot of the fossils into fragments, and some of the fossils crumbled into pieces as they dried out. All told, 20,000 pieces were recovered and painstakingly fit back together like a gigantic jigsaw puzzle made of fossilized bones.

Neither specimen is complete but we have enough bones that scientists can estimate the animal’s size when it was alive—and it was huge! It probably grew up to 39 feet long, or 12 meters, and some individuals would certainly have been bigger. Initial estimates were even longer, up to 50 feet, or over 15 meters, but that was before the specimens were fully studied.

Like other pliosaurs, predator X had a short tail and big teeth in its long jaws. Its head was massive, around 7 feet long, or 2 meters, and its front flippers were probably about the same length. It had four flippers, and researchers think its front flippers did most of the work of swimming, with the rear flippers acting as a rudder, but it could probably use its back flippers for a little extra boost of speed when it needed to. But it was a strong, fast swimmer no matter what, probably as fast as a modern orca, and very maneuverable. It had to be, because it ate other marine reptiles like plesiosaurs that were themselves very fast swimmers. It undoubtedly also ate sea turtles and fish, and probably pretty much anything else it could catch. It didn’t eat whales because this was long, long before whales evolved.

Predator X got its nickname from reporters back when the paleontologists thought it was 50 feet long. It didn’t have a name yet so it got called Predator X because that sounded impressive (and it is), but it isn’t the only giant pliosaur known.

Kronosaurus was originally described in 1924 from fossils discovered in Australia, and current estimates of its size agree that it could probably grow to around 33 feet long, or 10 meters. This may be a low estimate, though, because the size of the biggest skull found might have been over 9 feet long, or 2.85 meters, although the skull isn’t complete so its full size is just an estimate. Pliosaurs do have big heads, but if Kronosaurus’s skull really is longer than predator X’s skull, it was probably a bigger animal overall.

Kronosaurus’s fossils have only been found in an ancient inland sea that covered most of Queensland and Central Australia until about 100 million years ago. It was probably a relatively shallow, cold sea, and although it had all the marine animals you’d expect for the time, like sharks, ammonites, ichthyosaurs, plesiosaurs, lungfish, sea turtles, and lots more, Kronosaurus was the apex predator. It was so big and deadly that a full-grown Kronosaurus didn’t have to worry about anything in the water.

Trying to figure out how big an extinct animal was from its fossil remains isn’t easy. It’s rare that an entire skeleton is discovered, so scientists have to make estimates of how big the missing pieces were, such as how long its tail was. Then they have to deal with the problem of how rare it is to find fossil specimens in the first place. The fewer specimens we have, the harder it is to decide how big a species may have grown overall. If you have 100 fossilized animals, you can measure them all and get a good idea how big most adults of that species got. If you have one fossilized animal, you don’t know if that particular individual was extra small or average or maybe the biggest one that ever lived.

All that aside, some of Kronosaurus’s teeth grew an entire 12 inches long, or 30 cm. Predator X had teeth the same size. So if you somehow invent a time machine and go back to the Cretaceous or Jurassic to look around, you might want to stay out of the water—or just bring an extra strong shark cage.

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 390: The Wallaby and Wiwaxia

Thanks to Jaxon and Lorenzo for their suggestions this week!

Further reading:

Rock-wallaby bite size ‘packs a punch’

Tiny Australian wallaby the last living link to extinct giant kangaroos

Extraordinary Fossil of Giant Short-Faced Kangaroo Found in Australia

Wiwaxia corrugata – The Burgess Shale

The nabarlek:

The banded hare-wallaby:

Wiwaxia was a little less cute than wallabies are:

An artist’s rendition of what Wiwaxia might have looked like when alive [picture from last page linked above]:

Show transcript:

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

Every so often I get an animal suggestion that I’m positive we’ve already covered, but then I’m flabbergasted when it turns out we haven’t. That’s the case for the animals we’ll learn about this episode, with thanks to Jaxon and Lorenzo!

A while ago, Jaxon left us a nice review and suggested we talk about wallabies. I was CONVINCED we’d talked about the wallaby repeatedly, but I think I was thinking about the wombat. We’ve hardly ever mentioned the wallaby, and it’s such a great animal!

The wallaby is a marsupial that basically looks like a miniature kangaroo, although some species grow pretty large. The resemblance makes sense because kangaroos and wallabies are closely related, but everything else about the wallaby family tree is confusing. That’s because there are a lot of animals called wallabies that aren’t actually the same type of animal. “Wallaby” is just a catchall term used by people to describe any animal that looks kind of like a miniature kangaroo.

Wallabies are native to Australia and New Guinea, but various species have been introduced to other places where they’re invasive, including New Zealand, France, England, Scotland, and Hawaii. Most of these non-native populations happened by accident when pets or zoo animals escaped into the wild, but some were introduced on purpose by people who didn’t know they were causing damage to the local ecosystems.

One thing everyone knows about kangaroos, which is also true for wallabies, is that they hop instead of running. Their hind legs are extremely strong with big feet, and in fact the name of the family they share, Macropodidae, means big feet. So, you know, Bigfoot exists but maybe doesn’t look like most people think. The animal hops by leaning forward and jumping, with its big hind feet leaving the ground at about the same time, and landing at the same time too before it bounces again. Its big tail helps it balance. But there’s a lot more to this hopping than you might think.

While the wallaby or kangaroo has strong leg muscles, what’s even more important is that it has very strong, very elastic tendons in its legs. These basically act like massively strong rubber bands. When you stretch a rubber band, it stores energy that it releases when you let go of it and it snaps back and whips you in the thumb and you wonder why you did that because it hurt. The tendons in the wallaby’s legs store energy when it hops, and when it lands, the energy releases and helps bounce the animal right back into the next hop. Once it gets going, its muscles are only doing a fraction of the work to keep it hopping at high speed. Even better for the animal, a lot of its breathing is regulated by its movements when it’s hopping, so it always has plenty of oxygen to power its body while moving fast. When it lands after a bounce, the impact pushes its breath out of its lungs, but the action of bringing its legs forward helps suck fresh air in. It’s an incredibly efficient way to move, and allows the animal to travel long distances to find food and water without spending a lot of energy.

Wallabies eat plants, and naturally the bigger species can eat bigger, tougher plants than smaller species. The exception is the dwarf rock-wallaby, according to a study published in March of 2024. There are over a dozen species of rock-wallaby, but in general they live in small groups in rocky areas. They’re nocturnal and spend the day sleeping in shady areas among the rocks, under rock overhangs, or in small caves in cliffs. At night they come out to find plants, but because they live in such harsh environments, most of the plants are pretty tough. Two species of dwarf rock-wallaby in particular turn out to have incredibly strong jaws for their size, as strong as the jaws of much larger species. Their teeth are also larger to help them grind up tough plants, and one species, called the nabarlek wallaby, even grows new molars throughout its life as the old ones wear down. That’s the only marsupial known to grow new molars throughout its life.

The nabarlek is reddish-gray in color and only weighs about 3 ½ pounds at most, or 1.6 kilograms, and is barely more than a foot long, or 30 cm, with its fluffy tail almost doubling that length. When it hops, it curls its tail up over its back. It eats grass, ferns, and other tough plants. Like most species of wallaby, it’s endangered due to habitat loss and introduced predators like foxes.

Another very small wallaby is the banded hare-wallaby, which only has a few small populations remaining on a few islands. It’s almost exactly the same size and weight as the nabarlek and is gray with lighter speckles and darker stripes on its back. It’s also nocturnal and lives in brushy areas where it can hide easily.

Even though these wallabies are smaller than domestic cats, some 45,000 years ago there used to be a type of kangaroo that was extremely large. The short-faced kangaroo stood as tall as a big grey or red kangaroo, about five feet tall, or 1.5 meters, but was much bulkier—as much as twice the weight of a modern kangaroo. It was so heavy that some researchers think it couldn’t hop but actually walked on its hind legs instead like a person. (Bigfoot.)

A few years ago, scientists comparing the genetic sequence of the short-faced kangaroo to other macropods discovered that this big strong kangaroo’s closest living relative was the tiny banded hare-wallaby.

Our next animal is a suggestion from Lorenzo, who sent a bunch of requests a while back. Before we talk about the animal, I should probably explain the situation with the List. This is the list of topics that I want to cover, a lot of them suggestions from listeners and a lot of them animals I’ve added myself. It started out as a simple Word document, but after a few years I moved it over to a spreadsheet and divided it into categories. There’s a page for mammals, a page for birds, and so on. I copied and pasted Lorenzo’s suggestions into the reptiles page because I recognized the first few as reptiles, or at least therapsids.

Well, at some point I took a closer look at the list of Lorenzo’s suggestions and added a note, “these may not all be reptiles.” Then later I took an even closer look and added another note, “these down here are basal arthropods, why did you put them under reptiles?” But next to today’s animal, at some point I added the note “I think this is a bird.”

Dear listener, Wiwaxia is not a bird. Scientists aren’t actually sure what it is, but 100% it is not a bird. It lived just over half a billion years ago in the early to middle Cambrian period, which we talked about in episode 69 about the Cambrian explosion. That’s when life on earth evolved from relatively simple, tiny organisms to much larger and more complex ones. Many of the Cambrian animals look bizarre and confusing to us today because they’re so different from the animals we’re familiar with, and that’s the case for Wiwaxia.

Wiwaxia grew about 2 inches long at most, or 5 cm, and slightly less wide. It was flat underneath like a slug, and it probably moved sort of like a slug too. The upper part of its body was covered in overlapping plates called sclerites, which acted as armor. As the animal grew older, it also developed spines that grew between the sclerites in two rows, with the longest spines growing 2 inches long, or 5 cm. Modern marine invertebrates have mineralized spines and scales that make them harder, but this hadn’t evolved yet and wiwaxia’s were basically the same material as the rest of the body, but tougher. Both the scales and the spines were shed and regrown every so often.

Like all the other animals in the Cambrian, wiwaxia lived in warm, shallow ocean water. It had a feeding apparatus at its front that had tiny conical teeth, and scientists think it used this feeding apparatus to scrape bacteria off the microbial mats that lived on the sea floor in most places, or it might have lived directly on the sea floor or on rocks. Either way, its feeding apparatus is enough like the radula found in modern mollusks that it’s been tentatively placed in the phylum Mollusca. This means it may be a very distant ancestor of slugs, snails, clams, mussels, oysters, squid, octopuses, and lots of other animals.

Wiwaxia was originally classified as an ancestor or at least a relation of modern polychaete worms, and a lot of scientists still think that’s correct. Since the original description of wiwaxia in 1899, a lot of specimens have been discovered in the Burgess shale in Canada, along with lots more found in China, Russia, the Czech Republic, and Australia, with more fossils found in other places that might be wiwaxia spines.

Because all the Cambrian fossils discovered are flattened, there’s a limit to how much we know about its anatomy when alive. The best fossils are reexamined frequently as new and more powerful methods of study are invented. Wiwaxia was apparently very common throughout the world between about 520 and 505 million years ago, so as more and more fossils are discovered, we’ll definitely learn more about 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 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 385: More Monitors

Thanks to Cosmo and Zachary for suggesting this week’s monitor lizards!

Further reading:

No One Imagined Giant Lizard Nests Would Be This Weird

The Mighty Modifications of the Yellow-Spotted Goanna

The Asian water monitor:

A yellow-spotted goanna standing up [picture by Geowombats – https://www.flickr.com/photos/geowombats/136601260/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=2595566]:

Show transcript:

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

Last week we had our big dragons episode where we learned about the Komodo dragon and some of its relations, including goannas. I forgot to thank Cosmo for suggesting the lace monitor, also called the tree goanna, in that episode, and I also forgot that Zachary had also suggested monitor lizards as a topic, so let’s learn about two more monitor lizards this week.

Cosmo is particularly interested in aquatic and semi-aquatic animals, and a lot of monitor lizards are semi-aquatic. Let’s learn about the Asian water monitor first, since it’s the second-largest lizard alive today, only smaller than the Komodo dragon.

The Asian water monitor is common in many parts of South and Southeast Asia, including India, Vietnam, Cambodia, Laos, southern China, and many islands. A half dozen subspecies are currently recognized, although there may be more.

The largest water monitor ever reliably measured was 10 1/2 feet long, or 3.2 meters. It’s dark brown or black with yellow speckles and streaks, and young lizards have larger yellow spots and stripes. It lives wherever it can find fresh or brackish water, from lakes and rivers to swamps, ponds, and even sewers.

Like the crocodile, the Asian water monitor’s tail is flattened from side to side, called lateral compression, and it’s also very strong. It swims by tucking its legs against its sides and propelling itself through the water with its tail. It can dive deeply to find food, and while it prefers fresh water, it will swim in the ocean too. That’s why it’s found on so many islands.

Juvenile Asian water monitors spend most of the time in trees, but even a fully grown lizard will sometimes climb a tree to escape danger. Only saltwater crocodiles and humans kill the adults.

In some parts of its range, the water monitor is killed by humans for its meat and its skin, which is used as leather. In other parts of its range, it’s never bothered since it eats venomous snakes and animals that damage crops. It’s sometimes kept as a pet, although it can grow so big that many people who buy a baby water monitor eventually run out of room to keep it. That’s how so many have ended up in the waterways of Florida and other areas far outside of its natural range, from people letting pets go in the wild even though doing so is illegal and immoral.

While most of the time the water monitor isn’t dangerous to humans, if it feels threatened, it can be quite dangerous. Like the Komodo dragon and other monitor lizards, it’s venomous, plus its teeth are serrated, its jaws are strong, and it has sharp claws. It eats a lot of carrion, along with anything it can catch. A population in Java even enters caves to hunt bats that fall from the ceiling.

Zachary didn’t suggest a particular type of monitor lizard, so let’s learn about the yellow-spotted goanna. Goannas are a type of monitor lizard found in Australia, New Guinea, and some nearby areas. We talked about some of them last week, including Cosmos’s suggestion of the lace monitor, but after the episode was released I found an article I had saved over a year ago. It’s about the yellow-spotted goanna, and a remarkable discovery about how it takes care of its eggs.

The yellow-spotted goanna lives in parts of Australia and southern New Guinea, and a big male can grow up to five feet long, or 1.5 meters. It can swim and climb trees when it wants to, but mainly it stays on the ground, although it prefers to live near water if possible. It’s a fast runner and chases its prey instead of ambushing it. It eats small animals like rodents, birds, fish, insects, and reptiles, including other monitor lizards.

If you remember last week’s episode, the female tree goanna digs a hole into a termite nest to lay her eggs inside. The termites repair the hole in their nest, which means the eggs are nicely hidden from predators and protected from weather, and when the babies hatch they have lots of termites to eat. That’s weird enough, but the yellow-spotted goanna female has an even more interesting way of protecting her eggs.

The yellow-spotted goanna digs a big burrow to hide in, and it spends a lot of its time in the burrow when it’s not out hunting. Researchers assumed the female laid her eggs in the burrow, but every time they investigated a female’s burrow, it was empty.

In 2012, a herpetologist named Sam Doody hoped to figure out where the female hid her eggs. He thought the eggs might be buried inside the burrow. When a female left her burrow, he and his team examined the burrow carefully. Doody noticed that the dirt at the end of the burrow felt softer than the walls, and he dug into it carefully, convinced he would find the eggs right away.

Instead, he and his team kept digging, following the softer dirt. It took them hours and hours, since they had to be really careful, and the filled-in burrow just kept going. It descended five feet, or 1.5 meters, into the ground in a corkscrew shape, more properly called helical, and at the very bottom the team found a nest of ten eggs.

Since then, Doody and his colleagues have studied many other yellow-spotted goanna nests and they’re all helical in shape and as much as 13 feet deep, or 4 meters. The extreme depth is related to how long it takes the eggs to hatch, about 8 months. If the eggs were closer to the surface, they would get too hot and dry to hatch. There’s more moisture and a constant temperature deep underground.

It takes the female more than a week to dig her tunnel and the small nesting chamber at the bottom. She lays her eggs, then returns to the surface, letting the sandy soil collapse behind her to hide and protect the eggs. The females also frequently nest together, sometimes sharing a nesting chamber. Doody’s team once found a nesting chamber as big as a room of your home but only about as tall as a mattress, with more than 100 clutches of eggs laid in it. The females often re-use the same burrows year after year. When the eggs hatch, the baby lizards dig their way out of the nesting chamber–but they dig straight up instead of using the softer parts of the helical structure.

Other animals move into the loose soil of the nesting burrows, especially frogs. When excavating one burrow, Doody’s team found 418 frogs, along with numerous small reptiles, invertebrates, and even mammals, all of them spending the dry season comfortably inside the loose soil in the spiral burrow. I wonder if the mother lizard sometimes digs some of these frogs out to eat as a snack. Watch out, frogs!

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 384: Dragons Revisited

This week we need to thanks a bunch of listeners for their suggestions: Bowie, Eilee, Pranav, and Yuzu!

Further reading:

Elaborate Komodo dragon armor defends against other dragons

Giant killer lizard fossil shines new light on early Australians

A New Origin for Dragon Folklore?

The Wyvern of Wonderland

The Komodo dragon:

The beautiful tree goanna:

The perentie:

Fossilized scale tree bark looks like reptile scales:

Show transcript:

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

This week we’re going to revisit a popular topic we talked about back in episode 53. That episode was about dragons, including the Komodo dragon. Since then, Bowie has requested to learn more about the Komodo dragon and Eilee and Pranav both suggested an updated dragon episode. We also have a related suggestion from Yuzu, who wants to learn more about goannas in general.

We’ll start with the Komodo dragon, which gets its name because it’s a huge and terrifying monitor lizard. It can grow over 10 feet long, or 3 meters, which means it’s the biggest lizard alive today. It has serrated teeth that can be an inch long, or 2.5 cm, and its skin is covered with bony osteoderms that make it spiky and act as armor. Since the Komodo dragon is the apex predator in its habitat, it only needs armor to protect it from other Komodo dragons.

Fortunately for people who like to hike and have picnics in nature, the Komodo dragon only lives on four small islands in Indonesia in southeast Asia, including the island of Komodo. Young Komodo dragons have no armor and spend most of the time in trees, where they eat insects and other small animals. As the dragon gets older and heavier, it spends more and more time on the ground. Its armor develops at that point and is especially strong on the head. The only patches on the head that don’t have osteoderms are around the eyes and nostrils, the edges of the mouth, and over the pineal eye. That’s an organ on the top of the head that can sense light. Yes, it’s technically a third eye!

The Komodo dragon is an ambush predator. When an animal happens by, the dragon jumps at it and gives it a big bite from its serrated teeth. Not only are its teeth huge and dangerous, its saliva contains venom. It’s very good at killing even a large animal like a wild pig quickly, but if the animal gets away it often dies from venom, infection, and blood loss.

Like a lot of reptiles, the Komodo dragon can swallow food that’s a lot bigger than its mouth. The bones of its jaws are what’s called loosely articulated, meaning the joints can flex to allow the dragon to swallow a goat whole, for instance. Its stomach can also expand to hold a really big meal all at once. After a dragon has swallowed as much as it can hold, it lies around in the sun to digest its food. After its food is digested, which can take days, it horks up a big wad of whatever it can’t digest. This includes hair or feathers, horns, hooves, teeth, and so on, all glued together with mucus.

A Komodo dragon eats anything it can catch, and the bigger the dragon is, the bigger the animals it can catch. One thing Komodo dragons are just fine with eating are other Komodo dragons.

As we mentioned a few minutes ago, the Komodo dragon is a type of monitor lizard, and there are lots of monitor lizards that live throughout much of the warmest parts of the earth, including Australia. Yuzu suggested we talk about the goanna, which is the term for monitor lizards in the genus Varanus, although it’s also a term sometimes used for all monitor lizards. Goannas are more closely related to snakes than to other types of lizard.

Like the Komodo dragon, the goanna will eat pretty much any animal it can catch, and will also scavenge already dead animals. Smaller goannas mostly eat insects, especially the tiny goanna often called the short-tailed pygmy monitor or just the pygmy monitor. Its tail is actually pretty long for its size. It only grows about 8 inches long at most, or 20 cm, and babies are less than the length of your pinkie finger. It spends most of its time underground in a burrow, but comes out to hunt for grasshoppers and other insects, spiders, scorpions, and sometimes frogs and small snakes. Many species of goanna spend the hottest part of the day in a burrow, and some species will hibernate in winter.

Most goannas spend all their time on the ground unless they’re actually underground, but some live in trees. The tree goanna, also called the lace monitor or just lacy, can grow up to seven feet long, or over two meters, but is lightly built to climb around on tree branches looking for food. The tree goanna eats a whole lot of bird eggs, along with whatever animals it can catch in trees or on the ground. It eats a lot of carrion and will even get into trash cans if it smells food. When the female is ready to lay her eggs, she digs a hole in the side of a termite nest and lays them in the nest. The termites repair the hole, which hides the eggs, and when the babies hatch, they have lots of termites to eat. The mother goanna keeps watch on the termite nest and once her eggs hatch, she’ll dig into it again to let her babies out.

Genetic testing has discovered that the tree goanna is the closest living relative to the Komodo dragon, but another relative is the biggest goanna alive today in Australia. It’s called the perentie and it can definitely grow up to 8 and a half feet long, or 2.5 meters, and possibly close to 10 feet long, or 3 meters. That’s almost the length of the Komodo dragon.

Long as it is, the perentie isn’t very heavy for its size. It has big claws that allow it to dig quickly, so that if it feels threatened it can dig a burrow and hide in it in only a few minutes. It can also climb trees and is a fast runner. Sometimes it will rear up on its hind legs, propping itself up with its tail, to get a good look around. It’s covered with a maze-like pattern of spots and speckles, and it has a very long neck and a very long tail. Like most monitor lizards, its head is flattened so that it looks a little like a snake’s head. Also like other monitor lizards, it has a long forked tongue that it flicks in and out like a snake to detect the chemical signature of other animals nearby, sort of like smelling but with the tongue.

Also like other monitor lizards, the perentie has a venomous bite. Its venom isn’t all that strong, but you still wouldn’t want to get nipped by one. A big perentie will kill and eat just about anything it can catch, including wombats and small kangaroos. It’s not dangerous to humans, though, and in fact very few people in Australia have ever seen a perentie in the wild. It’s shy and lives in remote areas, mostly in the interior of the country over to the western coast.

There used to be a goanna in Australia that was even bigger than the perentie, but it went extinct around 50,000 years ago. We talked about it briefly in episode 325, but Pranav suggested we learn more about it. It’s called megalania and not only was it bigger than the perentie, it made the Komodo dragon look like a little baby lizard. Megalania may have grown as much as 23 feet long, or 7 meters, although most scientists these days think it wasn’t quite that big. The latest estimates are still pretty big, possibly 18 feet long, or 5.5 meters. It was also heavily built, more like the Komodo dragon than the perentie, so it may have weighed as much as a polar bear. That’s about 1200 pounds, or around 550 kg, but I thought the polar bear comparison was funny. We don’t know for sure how big megalania was because we don’t have a complete skeleton.

Megalania has been classified with the living goannas in the genus Varanus, so it was probably related to the Komodo dragon, although we don’t know exactly how closely. It was probably venomous, and we know its teeth were serrated like the Komodo dragon’s. It lived throughout much of eastern Australia and may have been even more widespread, we just don’t know because we don’t have very many fossils.

Megalania lived alongside another giant monitor lizard in what is now Queensland, the Komodo dragon. That’s right, the Komodo dragon once lived in Australia, although it went extinct there around 300,000 years ago. Megalania went extinct around the time that humans first arrived in Australia, so it’s very possible that the ancestors of today’s Aboriginal Australians encountered it. In 2015, a study was published detailing the discovery of a large goanna osteoderm from a cave system in Queensland. The osteoderm has been dated to about 50,000 years ago and probably belonged to megalania, and some scientists think humans may have been a factor in its extinction, along with climate change.

There are supposedly stories passed down for thousands of years among the Aboriginal Australian peoples that suggest meetings with megalania. I tried hard to find accounts of any of these stories to share, but the sources were always questionable. I did learn that European accounts of the Dreamtime, especially older ones, are inaccurate at best. European colonizers didn’t fully understand the Aboriginal cultures and in many cases weren’t interested in understanding them. They just wanted to collect stories that they would then change to fit the European worldview. This trend continues to the present day, with non-Aboriginal writers changing, misinterpreting, or even straight up inventing Dreamtime stories to fit their own interests. Sometimes that interest is cryptozoology. From what I was able to discover, there really is one aspect of the Dreaming that does apparently include a giant goanna, but that the traditions involved are especially sacred and not meant for outsiders to learn. So it’s none of our business.

As we discussed in episode 53, European stories about dragons were probably inspired by snakes, since early dragons were described as snake-like. Dragon stories in other parts of the world were probably inspired by various local reptiles such as crocodiles. Fossilized bones also played a part, since in the olden days no one knew what dinosaurs were. All anyone knew was that sometimes they found gigantic bones that seemed to be made of stone, and people made up stories to explain them.

Stories about giant reptiles are common throughout much of the world, and in 2020 a study was published suggesting that one of the reasons wasn’t an animal at all. It was a plant, specifically a 300 million year old plant called Lepidodendron, also called the scale tree.

The scale tree wasn’t actually a tree, but it was a really big plant that could grow 160 feet tall, or 50 meters. It’s been extinct for a long time, but it does have living relations called quillworts that kind of look like weird grass.

The scale tree gets its name from the diamond-shaped pattern on its trunk, which looks for all the world like reptile scales. These were just places where leaves once grew, but as the plant got taller, it shed its lower leaves as new ones grew from the top. Different species of the plant had different scale patterns. The study suggests that fossilized pieces of scale tree trunks inspired stories about giant reptiles. Since the plants grew throughout the supercontinent Pangaea and often ended up fossilized in coal beds, their fossils have been found in many different parts of the world.

Let’s finish with a dragon story from England, specifically the village of Sockburn in County Durham. It’s referred to as the Sockburn Worm, since “worm” used to mean any creature that was snakey or worm-shaped in appearance. It’s closely related to the story of the Lambton Worm that we talked about in episode 53.

Once upon a time in the olden days, maybe around 750 years ago, maybe longer ago, Sockburn and the farmland around it were terrorized by a dragon. The dragon had a poisonous breath and would eat anyone it came across, and killed and ate all the livestock it could find. No one could kill it.

Sir John Conyers was a knight who lived in the area and he decided he had to do something. He got dressed in his armor and went to the local church to pray, and said he would give up his only son’s life if it meant killing the dragon. Then he set out to find the dragon.

He didn’t so much find the dragon as the dragon found him. Instead of getting eaten, Sir John drew his magical sword and battled the dragon until finally he lopped its head off with one massive chop. Sir John survived and so did his son.

Centuries later, in 1855, a writer was inspired by the story and wrote a poem based on it. He eventually included the poem in a book called Alice Through the Looking-Glass, the sequel to Alice in Wonderland. You may know the poem “The Jabberwock,” and now you know the dragon story that inspired 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 383: The Marsupial Mole

Thanks to Catherine and arilloyd for suggesting the marsupial mole!

Further reading:

Northern marsupial mole: Rare blind creature photographed in Australian outback

The marsupial mole, adorable little not-mole from Australia [photo from article above]:

Grant’s golden mole, adorable little not-mole from Africa:

Show transcript:

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

This week we have a little short episode about a very small Australian animal suggested by two listeners: Catherine, who has the best name ever, and someone called arilloyd who left us a nice review and suggested this animal in the review. I’m not sure I’m pronouncing their name right, so apologies if not. The animal is the unusual but very cute marsupial mole.

There are two closely related species of marsupial mole, one that lives farther north than the other. They look very similar, with silky golden fur, strong, short legs with strong claws for digging, a very short tail, no external ears, and no eyes. The marsupial mole doesn’t have eyes at all. It doesn’t need eyes because it spends almost its entire life underground.

All this sounds similar to other moles, but the marsupial mole isn’t related to other moles. Other moles are placental mammals while the marsupial mole is a (guess, you have to guess), right, it’s a marsupial! That means its babies are born very early and crawl into the mother’s pouch to finish developing. The marsupial mole has two teats, so it can raise two babies at a time.

The marsupial mole grows around 6 inches long, or about 16 cm, and is a little chonky animal with a pouch that faces backwards so sand won’t get in it. It has a leathery nose and small teeth, and its front feet are large with two big claws.

We actually don’t know very much about the marsupial mole because it’s so seldom seen. Not only does it live underground, it lives in the dry interior of Australia, the Great Sandy Desert. It probably also lives in other desert areas of Australia.

Scientists think the marsupial mole originally evolved to dig not in desert sand but in the soft, wet ground in rainforests. Over millions of years Australia became more and more dry, until the rainforests eventually gave way to the current desert conditions. The marsupial mole had time to adapt as its environment changed, and now it’s extremely well adapted to living in sand. It sort of swims through the sand using its big paddle-shaped front feet, kicking the sand behind it with its back legs. Unlike other moles, the marsupial mole doesn’t dig permanent tunnels and the sand just collapses behind it.

While the marsupial mole can’t see, and probably doesn’t have great hearing by our standards, it does have a good sense of smell in order to sniff out insect eggs and larvae, worms, and other small, soft food. It probably searches mainly for insect nests where it can find lots of food at one time, like ant nests. There are also reports of it eating adult insects, seeds, and even small lizards.

The reason the marsupial mole looks and acts so much like placental moles is due to convergent evolution. The mole’s body shape and habits just work really well for an animal that wants to dig around and eat grubs. Like other moles, it has trouble regulating its body temperature since most of the time it doesn’t need to do so. If it gets too hot, it can dig deeper into the sand where it’s cooler.

The marsupial mole is most similar to a completely unrelated placental mammal, Grant’s golden mole, which lives in a few parts of coastal South Africa and Namibia in Africa. Grant’s golden mole lives in sandy areas and swims through the sand like the marsupial mole does. It mainly eats termites and other insects, but it will also eat small reptiles. Its fur is a sandy golden color and it has no external ears, no eyes, and three big claws on its front feet. It only grows about 3 and a half inches long, or 9 cm, which makes it the smallest golden mole. It’s nocturnal and emerges from the sand at night, often hunting aboveground to conserve energy. It mostly hunts by hearing, but since its ears are most effective when it’s underground, it will often stop and stick its head into the sand to listen for potential prey.

Other golden moles are a little bit larger and live in different parts of Africa in different environments, from forests to swamps. But while golden moles are placental mammals, they’re not actually moles despite the name. They look and act like moles, but they’re actually more closely related to the tenrec, which we talked about in episode 324. The golden mole just shares the same traits as true moles due to convergent evolution again.

Just like water animals that all eventually develop a fish-like body shape, it seems that all digging mammals eventually develop a mole-like body shape. That shape also happens to be really cute, which is just a little extra bonus for the animal.

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 375: The Praying Mantis Re-Revisited

Thanks to Elijah and an anonymous listener for suggesting that we talk about some more species of praying mantis!

Further reading:

The luring mantid: Protrusible pheromone glands in Stenophylla lobivertex (Mantodea: Acanthopidae)

Dragons and unicorns (mantises) spotted in Atlantic forest

Citizen scientists help discover new mantis species

The dragon mantis [photo from first article linked above]:

The possibly new species of unicorn mantis [picture from second article linked above]:

Inimia nat, or I. nat, discovered after a citizen scientist posted its photo to iNat [photo from third article linked above]:

Show transcript:

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

This week we’re going to revisit a popular topic that we’ve covered before, especially in episode 187, but which has been suggested by a couple of listeners who want to know more. It’s the praying mantis. Thanks to Elijah and an anonymous listener who suggested it. Elijah even keeps mantises as pets and sent me some pictures of them, which was awesome.

The praying mantis gets its name because it holds its spiny front legs forward and together, which sort of resembles someone holding their hands together while praying. That’s the type of praying spelled p r a y ing, not p r e y ing, which refers to killing and eating other organisms, but the praying mantis does that too. It’s a predator that will eat anything it can catch, including birds, fish, mice, lizards, frogs, and of course lots of insects.

There are thousands of mantises, also called mantids, with most species preferring tropical and subtropical climates. In general, a mantis has a triangular head with large eyes, an elongated body, and enlarged front legs that it uses to catch prey. Most species have wings and can fly, some don’t. Most are ambush predators.

We talked about several species of mantis in episode 187, and some more in episode 201. You can go back to those episodes to find out general information about mantises, such as how their eyes work and whether they have ears and whether they actually eat their mates (they do, sometimes). This week we’re going to focus on some findings about mantises that are new since those episodes came out.

The dragon mantis, Stenophylla lobivertex, was only discovered in the year 2000. Its body is covered with gray-green or green-brown lobes that help it blend in with the leaves in its forest home, but that also kind of make it look like a tiny dragon covered with scaly armor. Even its eyes are spiky. It lives in the tropics of South and Central America where it’s quite rare, and it usually only grows about an inch and a half long, or 4 cm. It spends most of the time in treetops, where it hunts insects, spiders, and other small animals.

Unlike many mantis species, the dragon mantis is mostly nocturnal. That’s one of the reasons why we don’t know a lot about it. In late 2017 through mid-2018, one member of a team of scientists studying animals in Peru noticed something weird in a captive female dragon mantis. Frank Glaw isn’t an expert in insects but in reptiles and amphibians, but he happened to observe what looked like two tiny maggots emerge from the mantis’s back, roughly above her last pair of legs, but then disappear again into her back. He thought he was seeing the results of parasitism, but a mantis expert suspected it was something very different.

Some praying mantis females release pheromones from a gland in about the same place on the back. Pheromones are chemicals that can be sensed by other insects, usually ones in the same species. They’re most often used to attract a mate. It turns out that the female dragon mantis has a Y-shaped organ that’s up to 6 mm long that can release pheromones in a particular direction. The mantis can even move the prongs of the Y around if she wants to. Because she only does this at night when she’s sure she’s safe, and only when she hasn’t found a mate yet, and because this species of mantis is really rare, no one knew that any mantis had this specific organ. It’s possible that other mantis species have the organ too, but that scientists just haven’t seen it yet.

As we learned in our previous mantis episodes, not only are there well over 2,000 known species of mantis alive today, there are more being discovered all the time. In 2019, Project Mantis went to Brazil to look for mantises, and not only did they find two of the extremely rare dragon mantises, they discovered what may be a species new to science. It hasn’t been described yet as far as I can find, but it appears to be a member of a group called unicorn mantises because it has a spike sticking up from the top of the head. Scientists have no idea what the spike is for, but it’s funny that they found unicorn mantises and dragon mantises in the same forest.

Late in 2023, two new species of Australian mantis were described, one of which is so different from other known species that it was placed in its own genus. They’re small mantises that live on tree trunks and are camouflaged to look like pieces of bark, so they’re hard to spot. Luckily, a citizen scientist named Glenda Walter noticed them and posted pictures to iNaturalist. A lot of scientists watch iNaturalist posts, and it’s a good thing because Glenda’s mantises turned out to be completely new to science. One of them has been named Inimia nat, which is abbreviated I. nat, which is also the abbreviation for iNaturalist. A citizen scientist is anyone who is interested in science and works to help improve scientific knowledge in general, for instance by taking pictures of interesting bugs and posting them to iNat.

The praying mantis has been around since at least the early Cretaceous, around 120 million years ago. The oldest remains found don’t look that much like modern mantises, though. They look more like cockroaches, which isn’t too surprising since mantises are closely related to cockroaches. By about 110 million years ago mantises had started to evolve the deadly front legs that they have now. Most fossilized mantis remains are actually impressions of wings, but experts can learn a lot from just the wings. Baby praying mantises have even been found preserved in amber from up to 87 million years ago.

A lot of people are scared of praying mantises because they look dangerous. They’re not dangerous to humans or pets at all, though. If you get pinched or nipped by a mantis, just wash your hands to clean out the wound and you’ll be fine. Mantises are extremely beneficial insects, especially in the garden, because they eat other insects that eat plants that humans don’t want eaten, like flowers and vegetables. Some people release mantises in the garden as a natural way to control insect pests. And, as Elijah can tell you, mantises actually make really interesting pets.

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!