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!

Episode 373: The Tasmanian Devil and the Thylacine

Thanks to Carson, Mia, Eli, and Pranav for their suggestions this week!

Further reading:

RNA for the first time recovered from an extinct species

Study finds ongoing evolution in Tasmanian Devils’ response to transmissible cancer

Tasmanian devil research offers new insights for tackling cancer in humans

The Tasmanian devil looks really cute but fights all the time [picture by JJ Harrison (https://www.jjharrison.com.au/) – Own work, CC BY-SA 3.0]:

The Thylacine could opens its jaws verrrrrrry wide:

Show transcript:

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

This week we’re going to cover two animals that a lot of people have suggested. Carson and Mia both want to learn about the Tasmanian tiger, and Eli and Pranav both want to hear about the Tasmanian devil. We talked about the Tasmanian tiger, AKA the thylacine, in episode 1, and I thought we’d had a Tasmanian devil episode too but it turns out I was thinking of a March 2019 Patreon bonus episode. So it’s definitely time to learn about both!

The thylacine was a nocturnal marsupial native to New Guinea, mainland Australia, and the Australian island of Tasmania, and the last known individual died in captivity in 1936. But thylacine sightings have continued ever since it was declared extinct. It was a shy, nervous animal that didn’t do well in captivity, so if the animal survives in remote areas of Tasmania, it’s obviously keeping a low profile.

The thylacine was yellowish-brown with black stripes on the back half of its body and down its tail. It was the size of a big dog, some two feet high at the shoulder, or 61 cm, and over six feet long if you included the long tail, or 1.8 meters. It had a doglike head with rounded ears and could open its long jaws extremely wide. Some accounts say that it would sometimes hop instead of run when it needed to move faster, but this seems to be a myth. It was also a quiet animal, rarely making noise except while hunting, when it would give frequent double yips.

A 2017 study discovered that the thylacine population split into two around 25,000 years ago, with the two groups living in eastern and western Australia. Around 4,000 years ago, climate change caused more and longer droughts in eastern Australia and the thylacine population there went extinct. By 3,000 years ago, all the mainland thylacines had gone extinct, leaving just the Tasmanian population. The Tasmanian thylacines underwent a population crash around the same time that the mainland Australia populations went extinct—but the Tasmanian population had recovered and was actually increasing when Europeans showed up and started shooting them.

Because the thylacine went extinct so recently and scientists have access to preserved specimens less than a hundred years old, and since the thylacine’s former habitat is still in place, it’s a good candidate for de-extinction. As a result, it’s been the subject of many genetic studies recently, to learn as much about it as possible. It’ll probably be quite a while before we have the technology to successfully clone a thylacine, but in the meantime people in Australia keep claiming to see thylacines in the wild. Maybe they really aren’t extinct.

The Tasmanian devil is related to the thylacine. It’s about the size of a small to average dog, maybe a bulldog, which it resembles in some ways. It’s compact and muscular with a broad head, relatively short snout, and a big mouth with prominent lower fangs. It’s not related to canids at all, of course, and if you just glanced at a Tasmanian devil, your first thought wouldn’t be “dog” or “thylacine,” it would probably be “giant mouse.”

The Tasmanian devil is black or grayish-brown, usually with patches of white on the chest and rump. It also has rounded pinkish ears, long whiskers, paws with relatively long toes, and a long tail. Since the devil stores fat in its tail, a fat-tailed devil is a happy, healthy devil.

It’s mainly a scavenger and will eat roadkill and other dead animals, although it will also kill and eat small or even large animals, and will also eat plant material and insects. It often eats every trace of a carcass, including bones and fur. This is good for other animals and for ranchers, since it reduces the presence of insects attracted to dead animals and reduces the spread of disease. Its digestion is extremely fast and efficient, and its jaws are extremely strong.

The Tasmanian devil is usually solitary, but it does get together with other devils to socialize and fight while eating. When a devil finds a carcass, it will make extremely loud calls to alert other devils to come share its meal. Then, because they’re called devils and not angels for a reason, the animals will fight over the food.

Tasmanian devils fight a lot. Researchers think the white markings help direct other devils to attack parts of the body that are less vulnerable to injury. The white fur is more visible in the dark, giving other devils a target. The white markings are usually on the devil’s chest, sides, and rump, with none on the face or legs. Males fight each other during breeding season, and the females pick the winners to mate with. If a female doesn’t like a male, she’ll fight him.

Devils are marsupials, which means babies are born very early and finish developing in their mother’s pouch. The Tasmanian devil’s pouch is rear-facing and contains four teats. The problem is, the mother has 20 or even 30 babies at a time. They’re born about the size of a jellybean and the only part that’s developed at that point is the forelegs so it can crawl into the mother’s pouch. The legs have claws and—you guessed it—the little squidge babies fight for a teat. Once one gets to a teat, it clamps on and doesn’t let go for the next three months. Babies that don’t get a teat die.

Like the thylacine, the Tasmanian devil once lived on mainland Australia but is now restricted to the island of Tasmania. Also like the thylacine, it shows low genetic diversity and was once killed for bounty by early settlers. It’s affected by habitat loss like many other animals, and it’s especially vulnerable to being run over by cars because it eats so much roadkill.

But the devil’s biggest issue today is a disease called devil facial tumor disease, or DFTD. DFTD is spread when an infected animal bites another one, which causes cancerous growths in and around the mouth. After a few months the tumors get so big that the devil can no longer eat and starves to death. Since devils bite each other all the time, the disease spreads quickly throughout a population.

In 2019 some researchers predicted the Tasmanian devil would be extinct by 2024. But here it is 2024 and not only is the devil not extinct, it’s actually doing a lot better now than it was just a few years ago.

Part of that is due to conservation efforts, where healthy devils are quarantined from infected ones in captive breeding programs. But part of it is natural. In 2018 a small population of devils was discovered that appeared to have developed a natural resistance to DFTD. Genetic studies done since then revealed some surprises. Not only are younger devils showing a genetic resistance to DFTD, there’s evidence that resistance to other transmissible cancers has developed in the past. Researchers think the Tasmanian devil might be especially prone to transmissible cancers but is also able to develop resistance relatively quickly. The devils with this resistance start growing tumors, but then the tumors stop growing and soon just disappear. Naturally, scientists are looking at the genetics of this trait to see if it can be applied to humans with certain types of cancer.

While Tasmanian devils fight each other, they don’t actually fight humans. Scientists report that it’s actually quite easy to work with. This makes it a lot easier to check the health of a captured animal. Hopefully it won’t be long before the entire population of Tasmanian devils is healthy and its numbers start to increase again.

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 365: A New Temnospondyl

Let’s take a look at some new findings about the temnospondyls this week!

Further reading:

Ancient giant amphibians swam like crocodiles 250 million years ago

Fossil of Giant Triassic Amphibian Unearthed in Brazil

Kwatisuchus rosai was an early amphibian [picture taken from article linked above]:

Koolasuchus was a weird big-headed boi:

Show transcript:

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

This week we’re going to revisit an animal we talked about way back in episode 172, the temnospondyl. That’s because a new species of temnospondyl has been named that lived about 250 million years ago, and some other new information has been published about temnospondyls in general.

In case you haven’t listened to episode 172 in a while, let’s brush up on some history. The temnospondyls arose about 330 million years ago during the Carboniferous period. Ocean levels were high, the continents were coming together slowly to form the supercontinent Pangaea, and much of the land was flooded with warm, shallow water that created enormous swampy areas full of plants. Naturally, a whole lot of animals evolved to live in the swamps, and the temnospondyls were especially successful.

Temnospondyls were semi-aquatic animals that probably looked a lot like really big, really weird salamanders. This was before modern amphibians evolved, and scientists still aren’t sure if the temnospondyls are the direct ancestors of modern amphibians or just cousins that died out with no living descendants. Temnospondyls do share many traits with modern amphibians, but they still had a lot in common with their fish ancestors.

Most temnospondyls had large heads that were broad and flattened in shape, often with a skull that was roughly triangular. Some had smooth skin but many had scales, including some species with scales that grew into armor-like plates. The earliest species had relatively small, weak legs and probably spent most of their time in the water, but it wasn’t long before species with stronger legs developed that probably lived mostly on land.

Many temnospondyls were small, but some grew really big. The biggest found so far is Prionosuchus, which is only known from fragmentary specimens discovered in Brazil in South America. It had an elongated snout something like a ghavial’s, which is a type of crocodilian that mostly eats fish, and a similar body shape. That’s why its name ends in the word “suchus,” which refers to a crocodile or an animal that resembles a crocodilian. Inside, though, prionosuchus probably had more in common with its fish ancestors than with modern crocodiles, and of course it wasn’t a reptile at all. It was an amphibian, possibly the largest one that’s ever lived. The biggest specimen found so far had a skull that measured just over 5 feet long, or 1.6 meters. That was just the skull! The whole animal, tail and all, might have measured as much as 30 feet long, or about 9 meters, although most paleontologists think it was probably more like 18 feet long, or 5-1/2 meters. That’s still incredibly big, as large as the average saltwater crocodile that lives today.

The resemblance of many temnospondyls to crocodilians is due to convergent evolution, since researchers think a lot of temnospondyls filled the same ecological niche as modern crocodiles. If you’re an ambush predator who spends a lot of time hiding in shallow water waiting for prey to get close enough, the best shape to have is a long body, short legs, a long tail that’s flattened side to side to help you swim, and a big mouth for grabbing, preferably with a lot of teeth. A study published in March of 2023 examined some trace fossils found in South Africa that scientists think were made about 255 million years ago by a temnospondyl. The fossils were found in what had once been a tidal flat or lagoon along the shore of the ancient Karoo Sea. You didn’t need to know it was called the Karoo Sea but I wanted to say it because it sounds like something from a fantasy novel. Truly, we live in a wonderful world. Anyway, there aren’t very many footprints but there are swirly marks made by a long tail and body impressions where the animal settled onto the floor to rest.

From those trace fossils, scientists can learn a lot about how the animal lived and moved. The swirly tail marks show that it used it tail to swim, not its legs. Since there are hardly any footprints, it probably kept its legs folded back against its body while it was swimming. When it stopped to rest, it may have been watching for potential prey approaching from above, since its eyes were situated on the top of its head to allow it to see upward easily. All these traits are also seen in crocodiles even though temnospondyls aren’t related to crocodilians at all.

Other big temnospondyls that filled the same ecological niche as crocodiles were species in the family Benthosuchidae. Some grew over 8 feet long, or 2.5 meters. That may not seem very big compared to a dinosaur or a whale, but this is your reminder that it was an early amphibian, and that amphibians are usually little guys, like frogs and newts.

The newly discovered fossil I mentioned at the beginning of this episode has been identified as a member of the family Benthosuchidae. It’s been named Kwatisuchus rosai and was discovered in Brazil in 2022. That’s a big deal, because while temnospondyl fossils have been found throughout the world, until Kwatisuchus, benthosuchids have only been found in eastern Europe. It was five feet long, or 1.5 meters, and it was probably an ambush predator that mostly ate fish.

Kwatisuchus lived only a few million years after the end-Permian extinction event, also called the Great Dying, which we talked about in episode 227. That extinction event wiped out entire orders of animals and plants. Temnospondyls in general survived the Great Dying and hung on for another 100 million years afterwards.

The last temnospondyl that lived, as far as the fossil record shows, was Koolasuchus. It lived in what is now Australia and went extinct about 120 million years ago. This is a lot more recent than most temnospondyls, so much so that when it was first discovered, scientists at first didn’t think it could be a temnospondyl. It was only described in 1997, although it was first discovered in 1978.

Not only was Koolasuchus the most recently living temnospondyl, it was also big and heavy and very weird-looking. It was about 10 feet long, or about 3 meters, and might have weighed as much as 1,100 lbs, or 500 kg. It lived in fast-moving streams and filled the same ecological niche as crocodiles, which eventually replaced it after it went extinct.

Like its relations, Koolasuchus had a roughly crocodile-shaped body with short legs and a fairly long tail, but its head was almost as big as its body. Most temnospondyls had big heads, and Koolasuchus’s was broad and rounded with a blunt nose. It also had what are called tabular horns that projected from the rear of the skull, which gave its head a triangular appearance. Its body was relatively slender compared to the chonky head, which made it look kind of like a really really big tadpole.

Remember, as an amphibian, Koolasuchus would have laid eggs that hatched into a larval form the same way frogs do today. We have a lot of larval temnospondyl fossils and even some fossilized eggs that paleontologists think were laid by a temnospondyl, which were attached to water plants the same way many species of frog do today. Larval temnospondyls did look a lot like tadpoles. In other words, Koolasuchus looked like a tadpole in shape but its larval form was also probably tadpole-like. Extra, extra tadpole-shaped.

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 363: The Dodo and Friends

Thanks to Wilmer and Carson for suggesting we revisit the dodo!

Further reading:

Dodos and spotted green pigeons are descendants of an island-hopping bird

On the possible vernacular name and origin of the extinct Spotted Green Pigeon Caloenus maculata

Giant, fruit-gulping pigeon eaten into extinction on Pacific islands

A taxidermied dodo:

The Nicobar pigeon, happily still alive [photo by Devin Morris – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=110541928]:

The 1823 illustration of the spotted green pigeon:

Show transcript:

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

This week we’re going to revisit a bird that everyone’s heard of but no one has seen alive, because it’s famously extinct. We talked about the dodo way back in episode 19, so it’s definitely time we talked about it again. Thanks to Wilmer and Carson for suggesting it! We’re also going to learn about some of the close relations of the dodo.

The first report of a dodo was in 1598 by Dutch sailors who stopped by the island of Mauritius in the Indian Ocean. Mauritius is east of Madagascar, which is off the eastern coast of Africa. The last known sighting of a dodo was in 1662, just 64 years later. The dodo went extinct so quickly, and was so little known, that for a couple of centuries afterwards many people assumed it was just a sailor’s story. But there were remains of dodos, and in the 19th century scientists gathered up everything they could find to study the birds. More remains were found on Mauritius.

In the wild, the dodo was a sleek bird that could run quite fast. It may have eaten crabs and other small animals as well as roots, nuts, seeds, and fruit. It was also probably pretty smart. People only thought it was dumb because it didn’t run away from sailors—but it had no predators on Mauritius so never had to worry about anything more dangerous than an occasional egg-stealing crab before.

When humans arrived on Mauritius, they killed and ate dodos and their eggs. What the sailors didn’t eat, the animals they brought with them did, like pigs and rats. It was a stark and clear picture of human-caused extinction, shocking to the Victorian naturalists who studied it.

A lot of the drawings and paintings we have of dodos were made from badly taxidermied birds or from overfed captive birds. At least eleven live dodos were brought to Europe and Asia, some bound for menageries, some intended as pets. The last known captive dodo was sent to Japan in 1647.

The dodo grew over three feet tall, or almost a meter, with brown or gray feathers, a floofy tuft of gray feathers as a tail, big yellow feet, and a weird head. The feathers stopped around the forehead, making it look sort of like it was wearing a hood. Its face was bare and the bill was large, bulbous at the end with a hook, and was black, yellow, and green. The dodo looks, in fact, a lot like what you might expect pigeons to evolve into if pigeons lived on an island with no predators, and that’s exactly what happened.

The dodo’s closest living relation is the Nicobar pigeon, which can grow 16 inches long, or over 40 cm. Like other pigeons, the dodo’s feathers probably had at least some iridescence, but the Nicobar pigeon is extra colorful. Its head is gray with long feathers around its shoulders like a fancy collar, and the rest of its body is metallic blue, green, and bronze with a short white tail. Zoos love to have these pigeons on display because they’re so pretty. It’s a protected animal, but unfortunately it’s still captured for sale on the pet black market or just hunted for food. It only lays one egg a year so it doesn’t reproduce very quickly, and all this combined with habitat loss make it an increasingly threatened bird. Scientists are trying to learn more about it so it can be better protected.

The Nicobar pigeon lives on a number of islands in the South Pacific and it can fly. Sometimes an errant individual is discovered in Australia, often after storms. Imagine going into your back yard one day and seeing a 40-centimeter-long bird whose feathers shine like jewels! The Nicobar pigeon lives in small flocks and eats seeds, fruit, and other plant material.

An even closer relative to the dodo is also the most mysterious. We don’t even know for sure if it’s extinct, although that’s very likely. It’s the spotted green pigeon and we only have one specimen–and we don’t even know where it was collected, just that it was an island somewhere in the South Pacific. There used to be two specimens, but no one knows what happened to the second one.

For a long time researchers weren’t even sure the spotted green pigeon was a distinct species or just a Nicobar pigeon with weird-colored feathers, but in 2014, DNA testing on two of the remaining specimen’s feathers showed it was indeed a separate species. Researchers think the spotted green pigeon, the dodo, and another extinct bird, the Rodrigues solitaire, all descended from an unknown pigeon ancestor that liked to island hop. Sometimes some of those pigeons would decide they liked a particular island and would stay, ultimately evolving into birds more suited to the habitat.

The specimen we have of the spotted green pigeon is 13 inches long, or 32 cm. Its feathers are dark brown with green iridescence and it has long neck feathers like the Nicobar pigeon. It also has little yellowish spots on its wings and a yellow tip to its bill. Researchers think it was probably a fruit-eating bird that lived in treetops.

The only reason we know there were once two specimens of this mystery bird is from a book about birds published in 1783, where the author mentions having seen two specimens. There was also an 1823 book about birds with an illustration of the spotted green pigeon that differs from the known specimen in some details. Researchers think the illustration might have been painted from the now-missing specimen.

There’s more to this mystery, though, because in 2020 an ornithologist studied a 1928 book about Tahiti that mentioned a bird that sounds a lot like the spotted green pigeon. It was even called a pigeon in the book. Since the author of that book had drawn on studies made by her grandfather almost a hundred years before, and since her grandfather had interviewed Tahitians about their history and traditions and they told him about the pigeon, the ornithologist suggested the spotted green pigeon might actually be from Tahiti. Now that scientists have a clue about where to start looking for remains of the bird, we might learn more about it soon.

Also in 2020, a study was published about another pigeon from the Pacific Islands. Fossils of it were found on the island of Tonga, and the scientists determined that the bird probably went extinct soon after humans first arrived on the island 2,850 years ago. The pigeon has been named Tongoenas burleyi. It grew about 20 inches long, or 50 cm, not counting its tail. It could fly and probably spent a lot of its time in trees, eating fruit. There are lots of different trees on the island that produce really big fruit, some of it as big as a tennis ball. Scientists think the pigeon was adapted to swallow these huge fruits whole, digest them, and poop out the seeds. The trees still exist but they’re in decline and scientists think it may be because no birds remain on the island that can spread their seeds effectively.

We don’t have any feathers from the newly described pigeon, but it was probably colorful. We do have a lot of bones, because many charred bones have been discovered in cooking pits excavated by archaeologists.

We don’t know yet how or if Tongoenas is related to the dodo. The Pacific islands are home to at least 90 living species of pigeon, and many of them we don’t know much about. There are undoubtedly many more waiting to be discovered by scientists, whether living or extinct.

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 360: The Emu War

Apologies to patrons for redoing an old Patreon episode, but I have a cold and it’s the holidays.

The noble emu:

A baby emu (picture from this site, which has lots of good info about emus and lots more great pictures):

Show transcript:

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

I had a different episode planned to finish off the year, but I had lots of stuff to do for the holidays so I put it off, and then I came down with a cold. It’s just a cold, at least, and it’s not too serious, but I decided to repurpose a Patreon episode from early 2020 instead of making a new episode, because I don’t feel good. Apologies to my patrons for getting a rerun, but I did give the episode a brush-up and re-recorded it.

Our topic this week is a bird from Australia, the emu, but mostly we’re going to learn about the emu war that happened in 1932.

The emu is a large, flightless bird almost as big as an ostrich, over 6 feet tall, or 2 meters. Like the ostrich, it can run really fast, over 30 miles per hour, or 50 km/hour. It’s only distantly related to the ostrich, though, and in fact it’s much more closely related to the tiny kiwi of New Zealand.

The emu has long legs and a long neck, soft feathers that are gray and brown, and three toes on each foot. It also has small vestigial wings that are only about eight inches long, or 20 cm. The body feathers make the emu look shaggy, but the head and the upper portion of the neck are less heavily feathered so that it sort of looks like it’s wearing a fancy coat with a high collar. It also looks like it has a poofy wedge of a downward-pointing tail, but it actually doesn’t have much of a tail at all. What looks like a tail is mostly part of the body. The emu’s skeleton is built for running, which includes a modified pelvis and leg bones for the attachment of strong leg muscles.

In winter, the female puffs out her feathers and struts around to attract a mate while making drumlike calls. Females sometimes fight each other by kicking, especially if a female approaches a male who already has a mate. The male builds a nest on the ground by placing dry grass, sticks, bark, and other plant materials on a flat, open area where he can see any predators that might approach.

The female lays up to 15 green eggs that are around five inches long, or 13 cm. The male broods the eggs for the next eight weeks and doesn’t eat during that entire time, and only drinks whatever dew he can gather from the plants around the nest without leaving the nest. A male can lose a third of his weight while brooding. Meanwhile, the female often leaves and finds another mate, sometimes laying several clutches of eggs during the nesting season.

When the babies hatch, the father takes care of them for the next six or seven months, at which point they’re fully grown. While he’s in charge, the father won’t let any other emus near the chicks, even their mother. He teaches them to find food and if the babies feel threatened, they’ll run underneath him to hide. Baby emus have gray and white longitudinal stripes and are super cute.

The emu eats plants and insects, and will sometimes travel long distances to find enough food and water. It can go a long time without eating and several days without drinking. It usually only drinks once a day but it will drink a whole lot of water during that one time.

Some populations of emu migrate to the coast after breeding season, where they can find more food and cooler weather. But in 1932 in western Australia, migrating emus didn’t find their usual food supplies. They found a whole lot of wheat fields cultivated by former soldiers, who had been given land after World War I. The Australian government had encouraged the soldiers to clear the land of native vegetation and grow lots of wheat, which they did. Then the emus showed up.

Naturally, without their usual food to eat, the emus sampled the wheat plants. And they found the plants yummy. Also, even though there was a drought that year, there was plenty of water for the wheat, which meant plenty of water for emus. So the emus showed up and showed up and showed up, an estimated 20,000 emus eating as much wheat as they could hold and crashing through fences to get to it.

The farmers sent a group to speak to the Minister of Defence to get help. The Minister of Defence sent a major with a small handful of soldiers to deal with the birds, with the soldiers armed with two lightweight machine guns.

On November 2, 1932, the men encountered their first emus. The birds were too far away to shoot so the men tried to herd them closer, but the emus scattered instead of staying in a group. Two days later, the men encountered approximately a thousand emus and lay in wait until the birds were close enough to shoot at–but the gun jammed and the birds scattered again. At this point the soldiers had killed maybe two dozen birds in all.

That was enough that the emus had figured out the men were a danger. The men reported that each group of birds now had a lookout. The rest of the flock would eat while the lookout kept watch. When the lookout spotted the men, it warned the others and all the emus would scatter.

The men even tried mounting a machine gun on a truck to run the emus down. But the ground was too bumpy to aim while the truck was moving, plus it couldn’t outrun the emus. On one occasion a dead emu got tangled in the steering equipment and the truck crashed into a fence, destroying both the truck and the fence.

On November 8, the men were withdrawn after having only killed around 200 emus, but they’d used a quarter of the ammunition they’d been allotted to do that. One politician suggested sarcastically that the soldiers deserved a medal for their part in the war, and another politician pointed out that the medal should properly go to the emus.

But the emus were still a problem, so after more entreaties from farmers, the same men and guns were sent back to try again. They kept at it for the next month or so and did manage to kill maybe a few thousand birds, but for every bird they killed, they shot ten bullets. Finally they were recalled for good. The government put a bounty on dead emus instead, and the farmers put up larger and stronger fences. It wasn’t until the late 1960s that the bounty was canceled and the emu protected. The current population is large and healthy.

There used to be several smaller subspecies of emu, but they went extinct basically as soon as Europeans showed up. We’re lucky that the mainland emu survived the war and the bounty hunting so that we can appreciate it today.

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!