Category Archives: animals

Episode 319: The Phascogale

Posted on by

Podcast: Play in new window | Download (Duration: 6:41 — 7.8MB)

Subscribe: RSS | More

Thanks to Kristie for suggesting this week’s topic, the phascogale!

Further reading:

Red-tailed phascogales (all photos below come from this site)

Sleeping phascogale:

Wide-awake phascogales:

Show transcript:

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

Ages ago, Kristie suggested I look up the phascogale, a really cute Australian animal. It’s definitely adorable and a little bit weird, so let’s learn about it this week!

Like most mammals that live in Australia, the phascogale is a marsupial. That means that the babies are born very early, then finish developing in their mother’s pouch. In this case, though, the phascogale mother doesn’t have a real pouch. Instead, when the mother is pregnant she develops what’s called a pseudo-pouch. Pseudo means false, so it’s not really a pouch although it resembles one. The pseudo-pouch is made up of folds of skin that develop around the mother’s teats, which protects the babies and keeps them warm. Since every baby needs its own teat at this stage, and the mother only has eight teats, if more than eight babies are born, the extra ones die.

The babies stay in the pseudo-pouch for about a month and a half, at which point they’re big enough that the mother can’t carry them around anymore. She makes a nest for them in a hollow tree, where they stay for another several months. She leaves them in the nest while she finds food, but comes back periodically to take care of them.

The phascogale is silvery-gray or gray-brown with a long tail that’s fluffy and black toward the end. It looks sort of like a mouse or rat with a long nose and a squirrel-like tail that’s almost as long as its body. It’s almost as big as a squirrel, up to about 10 inches long not including its tail, or 26 cm. Despite its resemblance to a rodent, the phascogale isn’t related to rodents at all. Rodents are placental mammals, not marsupial mammals.

The phascogale is nocturnal and mostly eats insects and spiders, but it will eat birds and mice too. It especially likes to eat cockroaches, yum. It mostly lives in trees although it will also hunt on the ground or in low brush, and it can jump long distances.

During the day the phascogale sleeps in a little hollow in a tree. It actually enters torpor while it’s asleep in order to save energy, which means it lowers its metabolic rate and its body temperature. But it can rev itself up again in only a few minutes when it needs to.

The strangest thing about the phascogale is that after mating season the males die. Mating season takes place over about three weeks in mid-winter, during which time a female may mate with several males. She’s able to store sperm in her body until she’s ready to have babies several months later, at which point she uses the stored sperm to fertilize her eggs. As a result, babies born in a single litter may have different fathers.

The males expend so much energy during these three weeks of mating season that they die of stress-related illnesses. In captivity, where the males can be treated by a veterinarian, a male who survives his first mating season can live as long as three years, but he doesn’t mate again. The female usually only has one litter of babies in her life even if she lives for several years.

The phascogale is closely related to the antechinus, which looks similar but has a skinny tail instead of a fluffy one. Antechinus males also die after mating season, while females give birth to tiny babies who latch onto a teat in the pseudo-pouch and stay there while they continue to develop, just like phascogales. Unlike phascogales, though, which always have eight teats, female antechinuses have different numbers of teats. How many teats a female has depends on where she lives. (Just a reminder, the word teats is another word for nipples.) Populations that live in areas where there’s plenty of food have more nipples, up to 13 but usually 12 at most. Populations that live in areas where it’s hard to find enough food have as few as 6 nipples. Producing milk for 12 or 13 babies requires a lot of energy, so females with more nipples can only survive and successfully raise that many babies when they have plenty of food. Females with only 6 nipples can survive on less food while still producing enough milk for six babies.

It seems strange that phascogale and antechinus males die after mating, but from an evolutionary standpoint, it makes sense. Both these animals are small and very likely to end up eaten by a larger animal. Odds are good that any given male won’t live long enough to see a second mating season anyway, so instead of conserving energy to stay alive, he expends all his energy during his first mating season to make sure he passes his genes along to the next generation.

One last interesting fact about the phascogale is that the red-tailed phascogale doesn’t need to drink water. It gets all the moisture it needs from its diet, which remember consists of insects and other animals. I guess animals are pretty moist on the inside. Don’t think about that too hard.

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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. 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 318: The Mysterious Malagasy Hippo

Posted on by

Podcast: Play in new window | Download (Duration: 15:41 — 17.8MB)

Subscribe: RSS | More

Thanks to the Tracing Owls podcast for this week’s suggestion. I’m a guest on that podcast so make sure to check it out (but while my episode is appropriate for younger listeners, most episodes are not, so be warned).

Further reading:

Huge Hippos Roamed Britain One Million Years Ago

Kenyan fossils show evolution of hippos

The Kilopilopitsofy, Kidoky, and Bokyboky: Accounts of Strange Animals from Belo-sur-mer, Madagascar, and the Megafaunal “Extinction Window”

A sort-of Malagasy hippo:

Actual hippo (not from Madagascar, By Muhammad Mahdi Karim – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=121282994):

A modern hippo skull. There’s a reason the hippo is more dangerous to humans than sharks are [By Raul654 – Darkened version of Image:Hippo skull.jpg, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=242785]:

A pygmy hippo and its calf!

Show transcript:

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

This week we’re going to learn about a topic suggested by the host of the podcast Tracing Owls, because I’m actually a guest on that podcast in an upcoming episode! I think the episode releases later this week. I’ll put a link in the show notes, but be aware that while the podcast is interesting and often very funny, with topics that focus on weird stuff related to science, most episodes are not appropriate for younger listeners. (I think my episode should be okay.)

Several years ago now there was a movie called Madagascar, which is about a group of zoo animals that end up shipwrecked on the island of Madagascar. I love this movie, especially the lemur King Julian, but one of my favorite characters is a hippopotamus named Gloria, voiced by Jada Pinkett Smith. The island country of Madagascar is off the southeastern coast of Africa, but as we talked about in episode 77, it’s been separated from the continent of Africa for millions of years and the animals of that country have mostly evolved separately from the animals of Africa. That’s part of why the movie Madagascar is so funny, since the main characters in the movie are all native to Africa—a lion, a zebra, a giraffe, and Gloria the hippo—and don’t know anything about the animals they encounter on Madagascar. Like this guy:

[King Julian clip]

But it turns out that hippos did once live on Madagascar, and that’s what we’re going to learn about today.

We’re not sure when the first humans visited Madagascar, but it was at least 2500 years ago and possibly as much as 9500 years ago or even earlier. By 1500 years ago people were definitely living on the island. It’s likely that hunting parties would travel to Madagascar and stay there for a while, then return home with lots of food, but eventually people decided it would be a nice place to live.

Madagascar is a really big island, the fourth largest island in the world. It’s been separated from every other landmass for around 88 million years, and has been separated from Africa for about 165 million years. Many of the animals and plants that live on Madagascar are very different from the ones living anywhere else in the world as a result.

To put this into perspective, here’s your reminder that the closest living relative of the hippopotamus is the whale, and 60 million years ago the common ancestor of both hippos and whales was a small semi-aquatic animal. That was about 28 million years after Madagascar was on its own in the big wide ocean, and 105 million years after the landmass that we call Africa broke off from the supercontinent Gondwana and began moving very slowly into the position it’s in today. When Madagascar finally broke free of the landmass we now call India, dinosaurs were still the dominant land animal.

So why are there remains of small hippos on Madagascar? How did the hippos get to Madagascar and why aren’t they still around? Did the hippo originate in Africa or in some other place? So many questions!

The ancestors of modern cetaceans, which includes whales and dolphins and their close relations, are found in the fossil record about 52 million years ago, although it might have been 53 or even 54 million years ago depending on which scientist you ask. That’s when the whale side of the suborder Whippomorpha started developing separately from the hippo side. The “morpha” part of Whippomorpha just means “resembling,” and I’m happy to report that the “whippo” part is actually a combination of the words whale and hippo. Truly, it gave me great joy when I learned this fact, because I assumed “whippo” was something in Greek or Latin, or maybe referred to an animal with a whip-like tail. Nope, whale+hippo=whippo.

Anyway, while we know a fair amount about the evolution of cetaceans from their semi-aquatic ancestors, we don’t know much at all about the hippo’s evolution. There’s still a lot of controversy about whether hippos really are all that closely related to whales after all. They share a lot of similarities both physically and genetically, so they’re definitely relations, but whether they’re close cousins is less certain. The confusion is mainly due to not having enough fossils of hippopotamus ancestors.

The modern hippo, the one we’re familiar with today, usually called the common hippo, first appears in the fossil record about six million years ago. We have fossils of animals that were pretty obviously close relations to the common hippo, if not direct ancestors, that date back about 20 million years. But it’s the gap between the hypothesized shared ancestor of both hippos and cetaceans that lived around 60 million years ago, and the first ancestral hippos 20 million years ago, that is such a mystery.

What we do know, though, is that while the common hippo is native to Africa, its ancestors weren’t. Hippo relations once lived throughout Europe and Asia, and probably migrated to Africa around 35 million years ago. In fact, hippos were common throughout Eurasia until relatively recent times. In 2021, a fossilized hippopotamus tooth was found in a cave in Somerset, England that probably lived only one million years ago. That was well before humans migrated into the area, which was a good thing for the humans because this hippo was humongous. It probably weighed around 3 tons, or 3200 kg, while the common hippo is about half that on average.

This particular huge hippo, Hippopotamus antiquus, lived throughout Europe and only went extinct around 550,000 years ago as far as we know. This was during a time that Europe was a lot warmer than it is today and hippos migrated north from the Mediterranean as far as southern England. The common hippo, H. amphibius, the one still around today, also migrated back into Eurasia during this warm period and its fossilized remains have been found in parts of England too.

These days, there are only two living species of hippo, the common hippo and the pygmy hippo. We talked about the pygmy hippo briefly in episode 135, including the astonishing fact that it only grows around 3 feet tall, or 90 cm, and lives in deep forests in parts of west Africa. There also used to be some other small hippos that evolved on islands and exhibited island dwarfism, and which probably weren’t closely related to the pygmy hippo. These include the Cretan dwarf hippopotamus that lived on the Greek island of Crete until around 300,000 years ago and maybe much more recently, and the Cyprus dwarf hippopotamus that lived on the island of Cyprus until only around 10,000 years ago. The Cyprus hippo was the smallest hippo found so far, only about 2.5 feet tall, or 75 cm. There are dogs larger than that! But the small hippo we’re interested in is the Malagasy pygmy hippopotamus.

There actually wasn’t just one hippo species that lived on Madagascar. Scientists have identified three species, although this may change as more studies take place and as new remains are found. The different species probably didn’t all live on the island at the same time, and some researchers think they might have resulted from three different migrations of hippos to the island.

But how did they get to the island? Madagascar is 250 miles away from Africa, or 400 km, way too far for a hippo to swim. The Malagasy hippos were well established on the island, too, not just a few individuals who accidentally reached shore. That means there must have been some way for hippos to reach Madagascar fairly easily at different times.

The best hypothesis right now is that at times when the ocean was overall shallower than it is now, such as during the Pleistocene glaciations, there are enough small islands between Africa and Madagascar that hippos could travel between them pretty easily. Since those islands would be far underwater now, we don’t have any way to know for sure. We can’t exactly dive down and look for hippo fossils, unfortunately.

The really big question, of course, is whether any hippos still survive on Madagascar. We know they were around as recently as 1,000 years ago, because we have subfossil remains. (Just a reminder that subfossil means that the remains are either not fossilized, or only partially fossilized.) Not only that, the bones show butchering marks so we know people killed and ate the hippos. Right now scientists think the hippos were hunted to extinction by the humans who settled on Madagascar, but there’s some evidence that it happened much more recently than 1,000 years ago.

Over the last several hundred years, European colonizers of Madagascar collected stories from Malagasy natives about animals that resemble hippos. More recently, some stories have also been collected by scientists.

In 1995, a biologist named David Burney, who was studying recently extinct animals on Madagascar, interviewed some elderly residents in various villages. He wasn’t actually trying to learn about mystery animals, he was mostly just trying to find the paleontological sites scientists had found decades before. He figured the older residents would remember those scientists’ visits, and he was right. But the residents also had other stories to tell about the bones dug up by scientists. Some of them said those bones belonged to animals they had seen alive.

In one village, several different people told a story about a cow-sized animal that had occasionally entered the village at night. It was dark in color and made distinctive grunting sounds, and had large floppy ears. When some people approached it too closely, it ran back to the water and submerged.

Dr. Burney thought the residents might have seen pictures of an elephant and transferred some of its details to the mystery animal, especially the large size and floppy ears. But when he showed a picture of an elephant to them, they were clear that it wasn’t the same animal. They chose a picture of a hippo instead, but said the animal they’d seen had larger ears. Various witnesses also said the animal had a large mouth with really big teeth, that its feet were flat, and that it was the size of a cow but didn’t have horns. One man even imitated the animal’s call, which Burney reported sounded like a hippopotamus even though the man had never seen or heard a hippo.

Burney was cautious about publishing his findings, and in fact in his article he mentions that even at the time, he and his team of scientists were cautious about even pursuing information about living Malagasy hippos. They didn’t want to be seen as acting like cryptozoologists, which says a lot about how cryptozoologists conduct their research. Cryptozoology isn’t a scientific field of study despite its name. Biologists, paleontologists, and other experts research mystery animals all the time. That’s just part of their job; they don’t have to call themselves something special. It’s unfortunately common that people who call themselves cryptozoologists don’t have a scientific background and may not know how to conduct proper field research. Very often, cryptozoologists also don’t know very much about the animals that definitely exist, and how can you determine what a true mystery animal is if you don’t know about non-mystery animals?

Luckily, Dr. Burney and his team decided to pursue this particular mystery animal, along with some others they learned about. The last hippo-like animal sighting they could pin to a particular date happened in 1976. If the animal in question was a hippo, and it really was alive only about 50 years ago, it might have gone extinct since then. Or it might still be alive and hiding deep in the forests of Madagascar.

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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. 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!

This is what a hippo sounds like, and you hear it all the time on this podcast because I like it:

[hippo sound]

Episode 317: Wild Ponies

Posted on by

Podcast: Play in new window | Download (Duration: 14:04 — 15.7MB)

Subscribe: RSS | More

Thanks to Leo for suggesting this week’s topic, the ponies of Assateague Island!

Further reading:

Assateague Wild Ponies

Some ponies running free on Assateague Island [photo taken from the site linked above]:

Show transcript:

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

This week we’re going to learn about the feral horses of Assateague! Thanks to Leo for the suggestion! That’s the grown-up Leo; we also have a young Leo who’s sent some great suggestions, including one we’re hopefully going to get to pretty soon.

Before we talk about Assateague ponies, though, we need to start somewhere else. The kelpie is a Scottish water spirit that’s supposed to appear as a pony wandering by itself, but if someone tries to catch the pony or get on its back to ride it, suddenly it drags the person into the water and either drowns them or eats them. It’s said that the only way to tell that the pony isn’t really a pony is to examine its feet. A real pony has hooves, but a kelpie has claws.

The story comes from the olden days when it was common to see ponies wandering around loose in Scotland and other parts of the UK. Some of the ponies in these areas were semi-feral, meaning they lived a lot of the time like wild animals. Some ponies were kept in stables and farmyards as working animals, but others were allowed to roam around and feed themselves as they liked. Every so often the wild ponies would be rounded up and any young ones branded by their mother’s owner. Sometimes the owner would need another pony to pull a cart or something, and they’d catch one of their ponies and bring it home to train. Sometimes the owner needed money so would catch some of their ponies to sell. The ponies that lived this way had to be tough and hardy to survive almost without human care, but luckily ponies are famously tough.

Ponies are a type of small horse, but they’re still horses. They’re generally sturdy, with a thicker coat than a full-sized horse, and usually stand around 14 hands high at the withers at most. The withers is the little bump of shoulder at the base of a horse’s neck, and the horse’s back starts behind the withers. A hand is an old horse measurement that has been standardized to four inches, or just over 10 cm, roughly the width of an adult person’s hand. 14 hands is equivalent to about 4 and a half feet tall, or 1.4 meters.

One of the best-known pony breeds is the Shetland pony, which also happens to be one of the smallest. It only stands 42 inches tall at most, or 107 cm. That’s about 3 and a half feet tall. It’s mostly used as a child’s mount but originally the Shetland was used to pull carts and plows and carry heavy loads, since despite its small size the Shetland pony is incredibly strong.

The Shetland comes from the Shetland Isles off the northeastern coast of Scotland, where it’s lived for at least two thousand years and probably more like 3,000. The islands get very cold in winter and there isn’t a lot of food, so over time the ponies evolved to be small and tough to survive.

On the other side of the Atlantic Ocean, there are feral horses living on an island called Assateague. Assateague Island is off the eastern coast of the United States, closest to the states of Virginia and Maryland. They’re actually not technically ponies except that they’re small, since ponies actually share certain traits that differentiate them from horses, even though these differences aren’t enough to call ponies a subspecies of horse. But because the Assateague horses rarely grow taller than 4 and a half feet tall, or 140 cm, people call them ponies.

I’m going to stop here and tell you a personal story, because I’ve actually seen the Assateague ponies myself. I lived in Pennsylvania for a little while after I finished grad school, and at the time I had an awesome dog named Jasper, a Newfoundland I got through Newf rescue. Newfies are bred to be water dogs in the harsh coastal regions of Newfoundland, Canada, but Jasper had never seen the ocean. I knew he didn’t know or care, but it mattered to me that he got to experience the ocean at least once in his life. I had also wanted to see the Assateague ponies since I was a little girl and read Misty of Chincoteague and its sequels approximately 10,000 times, books by Marguerite Henry.

So I planned a trip to Assateague Island, which is a wildlife refuge these days. I decided to go over a weekend in October, when it wouldn’t be crowded. At the time I was working in a sales office while I tried to find a job I actually liked, and I mentioned my trip to my boss. He said he’d been to the island, and of course I asked if he’d seen the ponies. He said yes, and said, “We brought a picnic and put all the food on a picnic table while we looked around, and when we came back to our table the ponies had eaten all our food. I cried. As a grown man, I cried.”

That’s literally what he said, and he wasn’t kidding. He was genuinely mad at those ponies for eating his picnic, which I find hilarious even though at the same time, yes, getting your picnic eaten by wild ponies is no fun. I’m sorry I laughed. Still, it’s really funny. Also, you’re not supposed to leave food out where the ponies can find it so it was his fault.

Anyway, I took Jasper to Assateague Island not knowing what to expect, except that if I left any food out, ponies would eat it. This was the first time I’d visited the ocean so far north and so late in the year, so I was surprised that the water was actually chilly. It was beautiful, though, and I enjoyed walking along the beach with Jasper. I thought he might have fun chasing waves, but he was quite an old dog at this point and was happy just to walk with me, although what he really wanted to do was go home to his regular routine. So we didn’t stay long, but we did see ponies! (Unfortunately I have lost all the pictures I took of the ponies and of Jasper, since this was before I got my first smartphone and all I had was a terrible little camera.)

About 75 ponies live in the northern part of Assateague, which is controlled by the state of Maryland, with about 150 more living in the southern part of the island, which is controlled by the state of Virginia. It gets confusing here because the Virginia part of Assateague is the Chincoteague National Wildlife Refuge, but Chincoteague is actually a neighboring island that’s smaller than Assoteague but has a town, also named Chincoteague.

These islands are really very small. They’re barrier islands not far from the mainland coast, and while they change shape over time since they’re mostly just formed of sand, Assateague is only about 37 miles long, or 60 km, and only about 7 miles wide, or 11 km. Chincoteague is separated from Assateague by a small bay. The ponies in the Chincoteague National Wildlife Refuge are taken care of by the Chincoteague Volunteer Fire Department, and if you’ve read Misty of Chincoteague you probably already know what I’m about to tell you.

There are too many ponies on the island to thrive, no matter how small they are, because the island is so small. There’s just not enough food. The ponies eat whatever plants they can find in the salt marshes that make up large parts of the island, and they eat brush and seaweed and sometimes people’s picnics. Its small stature is mainly from its poor diet, since the foals don’t get enough nutrition when they’re growing.

In the early 19th century, the people of Chincoteague periodically rounded up some of the ponies and captured them, bringing them home to train and use as farm and riding animals. Hey, free horses! In 1924, the Chincoteague Volunteer Fire Department took over the task of pony penning, making it into an annual event in July that attracts thousands of tourists.

The ponies are rounded up and made to swim across the bay, which sounds horrible but it’s a short swim, only five or maybe ten minutes long. Mounted riders swim alongside to help any foals who have trouble. When the horses arrive on Chincoteague, they’re given a good feed and a veterinarian checks them over and treats them if needed. Then the older foals are separated from the herd to auction off. The proceeds of the auction fund the fire department, the ponies are saved from starving to death by keeping their numbers down, and the ponies that aren’t sold are allowed to return home. To solve the same issue in the northern part of the island, members of the Maryland herd are given contraceptives that stop them from having very many babies.

More recently, starting in 1990, veterinarians have started treating the Virginia ponies twice a year to vaccinate them and treat any injuries or illnesses. This helps keep the herd healthy since so many of the foals born will eventually go on to live on the mainland around other horses, so it’s important that the ponies don’t carry diseases.

Another reason to keep the number of ponies low is because ponies aren’t the only animals that live on Assateague Island. Whitetail deer live on the island along with a whole lot of birds, some of which are endangered. Sika deer also live in marshy areas of the island, although it’s not native to North America. It was introduced to the island from Asia in 1923, although I have no idea why. The sika is mostly dark brown but it retains its white fawn spots into adulthood, and it’s a large, attractive animal.

The ponies have been on Assateague for several hundred years, and by the 1920s they were in genetically poor shape overall. To reduce the effects of inbreeding, Shetland and Welsh ponies were added to the herd, and later twenty mustangs were released on the island too. Arabian stallions were also allowed to mate with some of the Assateague mares who were captured and later returned to the island when they were in foal. This helped the Assateague pony survive with improved genetic health, but it also made it harder to determine where the ponies came from in the first place.

The big mystery about the Assateague ponies is how they got to the island. No one knows. Some historians think white colonists set their horses loose on the island in the 17th century so they wouldn’t have to pay livestock taxes, and this is very likely. Many colonists were from parts of the UK where letting your ponies roam free until you needed them was a normal practice. Other animals were allowed to roam free on the island at the time too, including cattle and sheep, but there’s another possibility.

A local legend claims that the ponies originated from horses brought by Spanish Conquistadors traveling to Peru. When one of the Spanish ships wrecked nearby, the horses swam to Assateague Island and survived there. There are plenty of shipwrecks along that part of the coast, including Spanish galleons. Maybe one of those ships had tough little horses aboard, and now we have tough little horses on Assateague Island. Just be glad they’re not kelpies, and hide your picnics.

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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. 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 316: The Blobfish and a Round Bunny

Posted on by

Podcast: Play in new window | Download (Duration: 9:23 — 10.3MB)

Subscribe: RSS | More

This week we learn more about the blobfish thanks to Matilde’s suggestion, and we’ll also learn about a primitive rabbit.

Further reading:

In Defense of the Blobfish: Why the ‘World’s Ugliest Animal’ Isn’t as Ugly as You Think It Is

A rare rabbit plays an important ecological role by spreading seeds

The Amami Rabbit: A Living Fossil in the Wilds of Amami Ōshima [amazing photos in this article!]

The blobfish as we usually see it:

The blobfish as it looks when it’s in its deep-sea home:

The Amami rabbit is so so so round:

Show transcript:

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

This week we’re going to learn a little more about the blobfish, which is Matilde’s suggestion, and we’ll also talk about an unusual primitive rabbit that’s still alive today.

We talked about the blobfish briefly in episode 231. The blobfish lives on the sea floor in deep water near Australia and New Zealand. It grows about a foot long at most, or 30 cm, and has weak muscles and a weak skeleton, but it doesn’t need to be any stronger since the intense pressure of the water presses in around the fish all the time. Its gelatinous flesh is slightly less dense than the water around it, which means it can float just above the sea floor without much effort, just drifting along, giving its tail and broad fins a little flap every so often. It eats whatever detritus floats down from far above, although it also really likes to eat small crustaceans that live on the sea floor.

But wait, you may be thinking, I’ve seen pictures of the blobfish and it looks like a pinkish blob with a cartoony frown and a droopy nose. Is that blobfish a different one from the one I just described?

No! The trouble is that the blobfish lives in really deep water, up to 4,000 feet below the surface, or 1200 meters. That means that there’s up to 4,000 feet of water above the fish, and if you’ve ever had to carry a bucket of water more than a few steps, you’ll know that water is really heavy. So the blobfish has 4,000 feet of water pressing on it from all directions. This is naturally called water pressure, and at the depths where the blobfish lives, it’s 120 times higher than water pressure in, for instance, your bathtub.

At that water pressure, you could not survive for even one second. You would be instantly crushed into a messy blob if you were suddenly transported into water that deep, because your body is adapted to live on the earth’s surface. But the opposite is true for the blobfish. If it was suddenly transported to the earth’s surface, or at least the water’s surface, without all that comfortable pressure keeping its body in place like a really big exoskeleton you can swim through, the blobfish would expand. And that’s exactly what happens when a fishing net catches a blobfish and pulls it to the surface. It just goes BLOB all over the place.

The blobfish was voted the world’s ugliest animal in 2013, which doesn’t seem fair since no one looks good when they’ve exploded into a blob.

When the blobfish is alive in its deep-sea home, it’s silvery or grayish with little spikes all over its body. It’s a member of the family Psychrolutidae, sometimes called toadfish, and it has little black eyes near the top of its head sort of like a toad. Its head is large and wide, while its body tapers to a thin little flat tail.

We know almost nothing so far about the blobfish, but we do know a bit about some of its close relatives like the blob sculpin. The blob sculpin lives in the North Pacific Ocean in even deeper water than the blobfish, up to 9200 feet deep, or 2800 meters. That’s about a mile and three-quarters deep, or almost 3 kilometers. Deep-sea animals are mostly solitary, but the blob sculpin gathers in large numbers to spawn. The females choose a nesting area and they all lay their eggs in the same place. Then the males release sperm into the water that fertilizes the eggs. Some nesting areas have been found to contain well over 100,000 eggs! Not only that, but the females guard the nesting area, and as they hover over their eggs, their slow-moving fins help keep the eggs clean of sand and sediment, which allows the eggs to absorb more oxygen. It’s the first documented case of a deep-sea fish taking care of its eggs.

Deep-sea animals often live for a long time, and it’s estimated that the blobfish might live to be as much as 130 years old.

That’s about all we know about the blobfish right now, so let’s finish with some information about a different cute round animal, although not a blobby one. It’s the Amami rabbit that only lives on two tiny islands off the southern coast of Japan.

The Amami rabbit used to live throughout Asia but as modern species of rabbit evolved, it eventually died out on the mainland. Now it only survives on these two small islands, and although it’s now a protected species, it’s still endangered. It’s especially vulnerable to habitat loss and introduced predators like dogs and cats. There are probably only about 5,000 individuals alive today, most of them on Amami Island with only a few hundred on Tokuno Island.

The Amami rabbit differs from other rabbits in a number of ways. Its eyes are smaller, its ears are smaller, and it’s shaped differently from other rabbits, with a chonky body and short legs. It also lives in forested areas instead of open grasslands. It’s nocturnal, with thick dark brown fur and long claws that it uses to dig burrows and climb steep hillsides.

A female Amami rabbit only has babies once a year, called kits or kittens, and usually only one or two kits are born at a time. In autumn the mother rabbit digs a special burrow that may be several feet deep, or up to a meter, somewhere away from her regular burrow. She brings leaves in to line the nesting chamber, where she gives birth to her kits. But she doesn’t stay with her babies all the time. In fact, she leaves them and only comes back to feed them about once a day or every other day. To keep them safe while she’s gone, she closes the entrance to the burrow so snakes and other predators can’t get in. When she returns, she digs the entrance open and spends a few minutes feeding her kits. Then she leaves again and closes the entrance behind her.

When the babies are a little over a month old, they start digging their way out of the nest on their own to explore. At that point the mother leads them to her home burrow where they stay for a few more months before they leave to find their own territories.

The Amami rabbit eats plants, especially grass and ferns, but it also eats acorns and fruit. A study published in January 2023 reported that the rabbit eats the fruit of a parasitic flowering plant called Balanophora, including swallowing the seeds whole. The seeds travel through the rabbit’s digestive system unharmed and the rabbit poops them out later, which allows them to sprout in an area far from the parent plant. Since Balanophora doesn’t produce chlorophyll and instead needs a host plant that can provide it with nutrients, having a rabbit help spread its seeds is important. This discovery was a surprise to the scientists studying the rabbit, because modern species of rabbit don’t usually eat seeds.

Who knows how many more surprises the Amami rabbit and the blobfish might hold? Hopefully scientists will continue to learn more about them so they can be better protected.

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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. 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 315: Dogs and Cats

Posted on by

Podcast: Play in new window | Download (Duration: 9:52 — 11.5MB)

Subscribe: RSS | More

Thanks to Fabiana and Hazel for their suggestions this week, where we learn more about dogs and cats!

Further reading:

Gene mutation that makes dogs small existed in ancient wolves

Feline genetics help pinpoint first-ever domestication of cats

Cats Learn Names of Their Feline Friends

A cat (Dracula, specifically, with Dracula the toy):

A dog, in case you’ve never seen a dog before:

Show transcript:

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

This week we’re going to revisit two great topics suggested by two great listeners, Fabiana and Hazel. They suggested dogs and cats, respectively. We’ve covered both before, but there’s always more to learn about any animal. Let’s look specifically at two recent studies that can add to our knowledge.

We’ll start with Fabiana’s suggestion of dogs. Results of a study published in January of 2022 examined the genetics of wolves and dogs to see how small dog breeds developed. We’re not completely sure how domestic dogs are related to wolf species alive today, since dogs have been domesticated for tens of thousands of years, and were probably domesticated at different times in different places by different groups of people, and potentially domesticated from different species of wolf, and since wolves and dogs can interbreed and produce fertile offspring. It’s very complicated, to say the least.

Wolves are roughly the same size throughout the world, depending on species and environment. The gray wolf, which is native to the northern parts of North America and most of Eurasia, stands about 2 and a half feet tall at the shoulder, or about 85 cm, and weighs around 88 lbs, or 40 kg, on average, although wolves who live in warmer areas tend to be smaller. There are certainly dog breeds bigger than this, but there are lots of dog breeds that are much, much smaller. I mean, the Chihuahua only grows around 9 inches tall, or 23 cm, and usually barely weighs 6 lbs, or 2.7 kg.

The prevailing belief is that small dog breeds came about because people bred the smallest dogs together and chose the smallest puppies from that pairing to breed to other small dogs. That’s true, but the genetic capacity for small size had to be there to start with in order to breed a 6-lb Chihuahua from an 88-lb wolf, no matter how many generations of dogs were in between. Researchers knew the genetic code for this size difference had to be somewhere, but it took a decade of study before they found it.

Once they found the growth hormone mutation that could allow for very small size when expressed, they searched for it in over 200 dog breeds to see if it was there in all dogs. Sure enough, it was. The scientists hypothesized that the genetic mutation showed up after dogs were domesticated, somewhere around 20,000 years ago. To test this, they looked for the mutation in the genetic profiles of both living and extinct canid species.

To their surprise, the mutation was present in all of them, including the genetic profile of a Siberian wolf that lived 54,000 years ago. Without this mutation, we wouldn’t have Chihuahuas or Yorkshire terriers or other small dog breeds that so many people love. That means the mutation was beneficial for domesticated dogs, but at the same time it was mostly non-beneficial for wild canids.

When dogs were domesticated around 20,000 years ago, and possibly well before that, the world was in the middle of a glacial maximum. The climate throughout the entire Earth was considerably colder than it is today. Ocean levels were lower because so much water was frozen, with ice sheets covering northern Europe and North America to a depth of about 2 1/2 miles, or 4 km. Northern Asia had fewer ice sheets but was much dryer than it is today. In fact, the world was a lot dryer overall, so places that weren’t covered in ice were more likely to be deserts, leading to massive dust storms and just a general dustiness throughout the world. Most of northern Africa and central Australia were what’s called “tropical extreme desert,” which doesn’t sound like any fun, but a lot of Asia was a polar desert. Most of Europe and eastern North America that wasn’t covered in ice was tundra or taiga, and even the most hospitable parts of the world were mostly open woodland and savannas. In other words, this was a world that favored really big animals like mammoths and woolly rhinoceroses and giant deer and buffalo and moose, and wolves needed to be big in order to hunt this megafauna.

But the world wasn’t going to be so cold for much longer. The ice sheets began to melt as the climate worldwide warmed up around 19,000 years ago, which led to sea levels rising and all sorts of other dramatic changes. Humans took their dogs and migrated to lots of places where they’d never been able to live before. Before this, dogs were probably mostly hunting partners, but as life got easier for people as mild winters and rainy spring weather became more common, dogs were more likely to be pets as well as working animals. People started selecting for smaller dogs, since a small dog eats less and is just plain cute. If it weren’t for that little genetic mutation in canids, the smallest dogs wouldn’t be all that much smaller than a Labrador.

Next, Hazel suggested we learn more about cats. Cats were domesticated a lot more recently than dogs, and a genetic study published in December 2022 determined that all pet cats in the world today are descendants of wild desert cats domesticated about 10,000 years ago in the fertile crescent in the Middle East. As we learned in episode 166, this was around the time that people were developing farming, and farming means you need to store grain. If you store grain, you attract mice and other rodents. Wildcats started hanging around farms and houses to catch rodents, and since the humans didn’t want the rodents, they were fine with the cats. Farms that didn’t have any cats had more rodents eating their stored grain, so it was just a matter of time before humans made the next logical step and started taming wildcats so they could trade cats to people who needed them.

The study was led by a feline geneticist named Leslie Lyons, and I only mention her name because it’s so perfect that someone with the last name Lyons would study cats and their relatives. Lyons and her team compared genetic samples taken from cats throughout the world and determined that all domestic cats are descendants of animals who originally lived in the Fertile Crescent. This is the same conclusion as a 2008 study by a different group of scientists, but the genetic tools used these days are much more sophisticated.

Cats definitely started out as working animals just like dogs did, but it probably wasn’t too long until people were treating them like pets. Cats are cute and soft, and people just like animals. We know that cats were treated as more than just a useful thing to have around because of an archaeological discovery from 2004. A human burial site on the island of Crete dated to about 9,500 years ago contained the remains of a human along with jewelry and other items, but also the remains of a cat. The cat had been buried separately in its own tiny grave right next to the person. There’s no sign that the cat was killed on purpose, so it’s possible it died separately and was buried next to the person who loved it.

Two separate studies were published in 2022 about cats and names. One study determined that cats who live in a household with at least one other cat learn the other cats’ names as well as their own. The other study determined that cats who live in a household with more than one person learn the names of their people. Personally, I don’t know how my cats can possibly know their names considering I call them by so many pet names, including puppy and bunny and squishmallow and you horrible little monster. However, in an unscientific study conducted just now by me, with a sample of one, when I called Poe’s name, he looked up at me and Dracula, who was lying on the bed next to me, looked at Poe. So I guess they’ve figured it out.

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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. 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 314: Animals Discovered in 2022

Posted on by

Podcast: Play in new window | Download (Duration: 17:28 — 20.2MB)

Subscribe: RSS | More

Let’s learn about some of the animals discovered in 2022! There are lots, so let’s go!

Further Reading:

In Japanese waters, a newly described anemone lives on the back of a hermit crab

Rare ‘fossil’ clam discovered alive

Marine Biologists Discover New Giant Isopod

Mysterious ‘blue goo’ at the bottom of the sea stumps scientists

New Species of Mossy Frog Discovered in Vietnam

A Wildlife YouTuber Discovered This New Species of Tarantula in Thailand

Meet Nepenthes pudica, Carnivorous Plant that Produces Underground Traps

Scientists discover shark graveyard at the bottom of the ocean

Further Watching:

JoCho Sippawat’s YouTube channel

A newly discovered sea anemone (photo by Akihiro Yoshikawa):

A mysterious blue blob seen by a deep-sea rover:

A newly discovered frog:

A newly discovered tarantula (photo by JoCho Sippawat):

Show transcript:

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

It’s the 2022 discoveries episode, where we learn about some of the animals discovered in 2022! Most of the time these animals were actually discovered by scientists before 2022, but the description was published in that year so that’s when we first learned about them. And, of course, a lot of these animals were already known to the local people but had never been studied by scientists before. There are lots of animals in the world but not that many scientists.

The great thing is, so many animals get discovered in any given year that I have to pick and choose the ones I think listeners will find most interesting, which in a stunning coincidence turns out to be the ones that I personally find most interesting. Funny how that works out.

We’ll start in the ocean, which is full of weird animals that no human has ever seen before. It’s about a hermit crab who carries a friend around. The hermit crab was already known to science, but until a team of scientists observed it in its natural habitat, the deep sea off the Pacific coast of Japan, no one realized it had an anemone friend.

The sea anemone is related to jellyfish and is a common animal throughout the world’s oceans. Some species float around, some anchor themselves to a hard surface. Many species have developed a symbiotic relationship with other animals, such as the clownfish, which is sometimes called the anemonefish because it relies on the anemone to survive. Anemones sting the way jellyfish do, but it doesn’t sting the clownfish. Researchers aren’t sure why not, but it may have something to do with the clownfish’s mucus coating. Specifically, the mucus may have a particular taste that the anemone recognizes as belonging to a friend. If the anemone does accidentally sting the clownfish, it’s still okay because the fish is generally immune to the anemone’s toxins.

The clownfish lives among the anemone’s tentacles, which protects it from predators, and in return its movements bring more oxygen to the anemone by circulating water through its tentacles, its droppings provide minerals to the anemone, and because the clownfish is small and brightly colored, it might even attract predators that the anemone can catch and eat.

Anemones also develop mutualistic relationships with other organisms, including a single-celled algae that lives in its body and photosynthesizes light into energy. The algae has a safe place to live while the anemone receives some of the energy from the algae’s photosynthesis. But some species of anemone have a relationship with crabs, including this newly discovered anemone.

The anemone anchors itself to the shell that the hermit crab lives in. The crab gains protection from predators, who would have to go through the stinging tentacles and the shell to get to the crab, while the anemone gets carried to new places where it can find more food. It also gathers up pieces of food that the crab scatters while eating, because crabs are messy eaters.

The problem is that hermit crabs have to move into bigger shells as they grow. Anemones can move, but incredibly slowly. Like, snails look like racecar drivers compared to anemones. The anemone moves so slowly that the human eye can’t detect the movement.

What the team of scientists witnessed was a hermit crab spending several days carefully pushing and pinching the anemone to make it move onto its new shell. If it wasn’t important, the crab wouldn’t bother. The sea anemone hasn’t yet been officially described since it’s still being studied, but it appears to be closely related to four other species of anemone that also attach themselves to the shells of other hermit crab species.

In other marine invertebrate news, a researcher named Jeff Goddard was turning rocks over at low tide at Naples Point, California a few years ago. He was looking for sea slugs, but he noticed some tiny clams. They were only about 10 mm long, but they extended a white-striped foot longer than their shells. Goddard had never seen anything quite like these clams even though he was familiar with the beach and everything that lived there, so he took pictures and sent them to a clam expert. The expert hadn’t seen these clams before either and came to look for the clams in person. But they couldn’t find the clams again. It took ten trips to the beach and an entire year before they found another of the clams.

They thought the clam might be a new species, but part of describing a new species is examining the literature to make sure the organism wasn’t already described a long time ago. Eventually the clam research team did find a paper with illustrations of a clam that matched, published in 1937, but that paper was about a fossilized clam.

They examined the 1937 fossil shell and compared it to their modern clam shell. It was a match! But why hadn’t someone else noticed these clams before? Even Goddard hadn’t seen them, and he’s a researcher that spends a lot of time along the coast looking specifically for things like little rare clams. Goddard thinks the clam has only recently started extending its range northward, especially during some marine heatwaves in 2014 through 2016. He suspects the clam’s typical range is farther south in Baja California, so hopefully a future expedition to that part of the Pacific can find lots more of the clams and we can learn more about it.

We talked about deep-sea isopods just a few weeks ago, in episode 311. They’re crustaceans related to crabs and lobsters, but also related to roly-polies that live on land. The deep-sea species often show deep-sea gigantism and are referred to as giant isopods, and that’s what this newly discovered species is. It was first found in 2017 in the Gulf of Mexico and is more slender than other giant isopods. The largest individual measured so far is just over 10 inches long, or 26 cm, which is almost exactly half the length of the longest giant isopod ever measured. It’s still pretty big, especially if you compare it to its roly-poly cousins, also called pillbugs, sow bugs, or woodlice, who typically grow around 15 mm at most.

Before we get out of the water, let’s talk about one more marine animal. This one’s a mystery that I covered in the October 2022 Patreon episode. It was suggested by my brother Richard, so thank you again, Richard!

On August 30, 2022, a research team was off the coast of Puerto Rico, collecting data about the sea floor. Since the Caribbean is an area of the ocean with high biodiversity but also high rates of fishing and trawling, the more we can learn about the animals and plants that live on the sea floor, the more we can do to help protect them.

When a remotely operated vehicle dives, it sends video to a team of scientists who can watch in real time and control where the rover goes. On this particular day, the rover descended to a little over 1,300 feet deep, or around 407 meters, when the sea floor came in view. Since this area is the site of an underwater ridge, the sea floor varies by a lot, and the rover swam along filming things and taking samples of the water, sometimes as deep as about 2,000 feet, or 611 meters.

The rover saw lots of interesting animals, including fish and corals of various types, even a fossilized coral reef. Then it filmed something the scientists had never seen before. It was a little blue blob sitting on the sea floor.

The blue blob wasn’t moving and wasn’t very big. It was shaped roughly like a ball but with little points or pimples all over it and a wider base like a skirt where it met the ground, and it was definitely pale blue in color.

Then the rover saw more of the little blue blobs, quite a few of them in various places. The scientists think it may be a species of soft coral or a type of sponge, possibly even a tunicate, which is also called a sea squirt. All these animals are invertebrates that don’t move, which matches what little we know about the blue blob.

The rover wasn’t able to take a sample from one of the blue blobs, so for now we don’t have anything to study except the video. But we know where the little blue blobs are, so researchers hope to visit them again soon and learn more about them.

It wouldn’t be a newly discovered species list without at least one new frog. Quite a few frogs were discovered in 2022, including a tree frog from Vietnam called Khoi’s mossy frog. It lives in higher elevations and is pretty big for a tree frog, with a big female growing over 2 inches long, or almost 6 cm, from snout to vent. Males are smaller. It’s mostly brown and green with little points and bumps all over that help it blend into the moss-covered branches where it lives. That’s just about all we know about it so far.

Our next discovery is an invertebrate, a spider that lives in bamboo. Specifically it lives in a particular species of Asian bamboo in Thailand, and when I say it lives in the bamboo, I mean it really does live inside the bamboo stalks. Also, when I say it’s a spider, specifically it’s a small tarantula.

It was first discovered by a YouTuber named JoCho Sippawat, who travels around his home in Thailand and films the animals he sees. I watched a couple of his videos and they’re really well done and fun, and he’s adorable even when he’s eating gross things he finds, so I recommend his videos even if you don’t speak the language he speaks. I’m not sure if it’s Mandarin or another language, and I’m not sure if I’m pronouncing his name right either, so apologies to everyone from Thailand for my ignorance.

Anyway, Sippawat found a tarantula where no tarantula should be, inside a bamboo stalk, and sent pictures to an arachnologist. That led to a team of scientists coming to look for more of the spiders, and to their excitement, they found them and determined right away that they’re new to science. It was pretty easy to determine in this case because even though there are more than 1,000 species of tarantula in many parts of the world, none of them live in bamboo stalks. The new spider was placed in a genus all to itself since it’s so different from all other known tarantulas.

It’s mostly black and dark brown with narrow white stripes on its legs, and its body is only about an inch and a half long, or 3 1/2 cm. It can’t make holes into the bamboo plants itself, so it has to find a hole made by another animal or a natural crack in the bamboo. It lines its bamboo stalk with silk to make a little home, and while there’s a lot we don’t know yet about how it lives, it probably comes out of its home to hunt insects and other small animals since tarantulas don’t build webs.

Finally, let’s wrap around to the sea anemone again, at least sort of. If you remember episode 129, we talked about the Venus flytrap sea anemone, which is an animal that looks kind of like a carnivorous plant called the Venus flytrap. We then also talked about a lot of other carnivorous plants, including the pitcher plant. Well, in 2022 a new species of pitcher plant was discovered that has underground traps.

The pitcher plant has a type of modified leaf that forms a slippery-sided pitcher filled with a nectar-like liquid. When an insect crawls down to drink the liquid, it falls in and can’t get out. It drowns and is dissolved and digested by the plant. Almost all known carnivorous plants are pretty small, but the largest are pitcher plants. The biggest pitcher plant known is from a couple of mountains in Malaysian Borneo, and its pitchers can hold over 2 ½ liters of digestive fluid. The plant itself is a messy sort of vine that can grow nearly 20 feet long, or 6 meters. Mostly pitcher plants just attract insects, especially ants, but these giant ones can also trap frogs, lizards, rats and other small mammals, and even birds.

The newly discovered pitcher plant grows in the mountainous rainforests of Indonesian Borneo and is relatively small. Unlike every other pitcher plant known, its pitchers develop underground and can grow a little over 4 inches long, or 11 cm. Sometimes they grow just under the surface, with leaf litter or moss as their only covering, but sometimes they grow deeper underground. Either way, they’re very different from other pitcher plants in other ways too. For one thing, scientists found a lot of organisms actually living in the pitchers and not getting eaten by the plant, including a new species of worm. Scientists aren’t sure why some animals are safe in the plant but some animals get eaten.

The new pitcher plant is found in parts of Indonesian Borneo that’s being turned into palm oil plantations at a devastating rate, leading to the extinction or threatened extinction of thousands of animal and plant species. The local people are also treated very badly. Every new discovery brings more attention to the plight of the area and makes it even more urgent that its ecosystems are protected from further development. The fastest way to do this would be for companies to stop using so much palm oil. Seriously, it’s in everything, just look at the ingredients list for just about anything. I try to avoid it when I’m grocery shopping but it’s just about impossible. I didn’t mean to rant, but the whole palm oil thing really infuriates me.

You know what? Let’s have one more discovery so we don’t end on a sour note.

A biodiversity survey of two of Australia’s marine parks made some really interesting discoveries in 2022. This included a new species of hornshark that hasn’t even been described yet. It’s probably related to the Port Jackson shark, which grows to around five and a half feet long, or 1.65 meters, and is a slow-moving shark that lives in shallow water off the coast of most of Australia. Instead of a big scary mouth full of sharp teeth, the Port Jackson shark has a small mouth and flattened teeth that allow it to crush mollusks and crabs. The newly discovered shark lives in much deeper water than other hornsharks, though, around 500 feet deep, or 150 meters.

Another thing they found during the survey wasn’t a new species of anything, but it’s really cool so I’ll share it anyway. It was a so-called shark graveyard over three miles below the ocean’s surface, or 5400 meters. The scientists were trawling the bottom and when they brought the net up to see what they’d found, it was full of shark teeth–over 750 shark teeth! They were fossilized but some were from modern species while some were from various extinct species of shark, including a close relative of Megalodon that grew around 39 feet long, or 12 meters. No one has any idea why so many shark teeth are gathered in that particular area of the sea floor.

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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. 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 313: The Wolverine and the Kakapo

Posted on by

Podcast: Play in new window | Download (Duration: 13:42 — 15.1MB)

Subscribe: RSS | More

This week we learn about two interesting animals from opposite parts of the world! Thanks to Felix and Jaxon for suggesting the wolverine and the kakapo.

Further reading:

Study: Wolverines need refrigerators

Kakapo Comeback [this article has some fantastic pictures!]

The wolverine likes cold weather:

So many young kakapos!

The kakapo is a really big bird:

(Photo by Matu Booth)

Show transcript:

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

This week we’re going to cover two animals suggested by listeners who spell their names with an X. I had already picked out these topics from the list and just now noticed both suggesters have X’s in their names. Thanks to Jaxon and Felix for these suggestions!

First, Felix suggested we learn about the wolverine. We’ve talked about it before in episode 62, but there’s a whole lot more to learn about this uncommon animal.

The wolverine is a mustelid, which is a family that includes weasels, ferrets, and other small, long, skinny animals with short legs. But the wolverine is big and broad, although its legs are pretty short. It kind of looks like a small bear and stands about 18 inches tall at the shoulder, or 45 cm. It’s light brown with darker brown or black legs, muzzle, tail, and back, and some have silvery-gray markings too. Its tail is short but fluffy. It lives in cold, mountainous areas, including northern Canada and Alaska, Siberia, and parts of Norway, Sweden, and Finland.

The wolverine is mainly a scavenger of animals that are already dead, but it will also kill and eat pretty much anything it can catch. This includes rabbits, mice, rats, porcupines, geese, and other small or relatively small animals, but it sometimes kills animals a lot bigger than it is, like deer. It will also eat eggs, berries, seeds, and anything else it can find. It’s not a picky eater.

The wolverine nearly went extinct in the 19th century due to overhunting for its fur, which is mostly waterproof and frost-proof. People used it to line winter clothes. The wolverine is also vulnerable to habitat loss and climate change, since it needs deep snow and cold temperatures to survive.

Because the wolverine lives where winters are harsh, when it finds a lot of food, it will sometimes bury it in snow to eat later. It chooses a protected area between boulders or a natural crevice in rocks to put the dead animal, then covers it with deep snow to keep it fresh for longer, just like putting meat in a freezer. Females in particular need this stored food, because they give birth in winter and need lots of food so they can produce milk for their babies.

But if you’ve ever taken food out of the freezer, you know it’s hard as a rock. How does the wolverine eat meat that’s frozen solid? Not only does the wolverine have strong jaws and teeth, it actually has a special tooth in the back of the mouth that points inward, one on each side of the upper jaw. The inward-pointing tooth allows the wolverine to tear off chunks of frozen meat more easily. Other mustelids have this arrangement of teeth too.

A male wolverine roams widely through a large territory, which can sometimes be hundreds of square miles. Pairs often mate for life although they don’t spend a lot of time together, and sometimes a male will have two or three mates. In winter, the female digs a den deep into the snow to have her babies, and while she mostly takes care of them by herself, the father wolverine will visit from time to time and bring everyone food. The babies stay with their mother for up to a year, and sometimes the half-grown wolverines will go traveling with their dad for a while.

The wolverine is sometimes called the nasty cat because it has a strong smell, which it uses to mark its territory. “Nasty cat” is the funniest name for an animal I’ve ever heard.

Next, Jaxon suggested the kakapo, which is a weird and adorable bird. It’s flightless and nocturnal, lives only in New Zealand, and is a type of parrot. A flightless, nocturnal parrot!

The kakapo is really big even for a parrot. It can grow over two feet long, or 64 cm, but since it’s flightless its wings and tail aren’t very big. Its legs are relatively short considering it has to walk everywhere. It has green feathers with speckled markings, blue-gray feet, and discs of feathers around its eyes that make its face look a little like an owl’s face. That’s why it’s sometimes called the owl parrot. Males are almost twice the size of females on average.

The kakapo evolved on New Zealand where it had almost no predators. A few types of eagle hunted it during the day, which is why it evolved to be mostly nocturnal. Its only real predator at night was one type of owl. As a result, the kakapo was one of the most common birds throughout New Zealand when humans arrived.

The Maori discovered New Zealand around 700 years ago. They killed the kakapo to eat and to use its feathers in clothing, and they also brought dogs and the Polynesian rat that also liked to kill and eat the kakapo. Then a few hundred years ago Europeans arrived, bringing all sorts of invasive animals with them, and they also chopped down forests to create more farmland.

By the end of the 19th century, the kakapo was becoming increasingly rare everywhere. When Resolution Island was declared a nature reserve in 1891, early conservationists brought kakapos and kiwis to the island in an attempt to save them. But stoats and feral cats killed them all. Attempts to establish captive breeding programs weren’t successful either. By 1970, scientists worried that the kakapo was already extinct.

Fortunately, a few of the birds survived in remote areas. By now conservationists understood that they had to provide a safe environment for the birds, and that took a lot of effort. Several islands were chosen as kakapo refuges, and then all the introduced mammals on the islands had to be eradicated or relocated. This included animals like deer that ate the same plants that the kakapo relied on, as well as predators. Then native plants and trees had to be transplanted to the islands since they’d been mostly killed off by deer and other introduced animals.

Then, finally, all the kakapos scientists could find were relocated to the islands. There weren’t very many, and most of them were males. 65 birds were introduced to four islands and monitored carefully, both to make sure they settled in well and to make sure no predators found their way to the islands.

Kakapo females only lay eggs when they have plenty of high-protein food, especially the fruit of the rimu tree that only ripens every four or five years, so the females were given extra food to encourage them to breed more often. The extra food helped, but it turns out that when the females were allowed to eat as much as they wanted, most of the eggs they laid hatched male chicks. That was the opposite of what the kakapo needed, so conservationists experimented with the amounts of extra food they gave the birds until finally the eggs were hatching equal numbers of females and males.

Many parrot species mate for life and both parents help take care of the eggs and babies, but the kakapo handles things differently. Males gather on hilltops during breeding season and each male digs out a shallow bowl well apart from other males, sometimes several bowls connected with little trails. If a male gets too close to another male, they’ll fight. Each male stands in his bowl and makes a booming call by inflating a special sac in his throat. The bowl helps amplify the sound and often the male will construct his bowl near a surface that reflects sound, like rock. His calls can be heard three miles away in good conditions, or 5 km, and the sound attracts females.

This system of males competing in one area to attract females is called lekking, spelled L-E-K. We’ve actually talked about lekking before but I don’t remember if I specifically mentioned the term. The area where the males gather is called a lekking ground or an arena or sometimes just a lek. The females walk around inspecting each male, who booms and struts to show how strong and fit he is. If a female is especially interested in one male, she’ll approach him and he starts his courtship dance. This sounds fancy but for the kakapo, it basically means he turns his tail with his wings spread, then walks backwards towards the female. Weird dance, but the female kakapo thinks it’s cool.

After a female chooses a male, they mate and then the female leaves him and walks home. She builds a nest in a hollow tree or in a hidden crevice among roots or rocks, and lays one to four eggs. She takes care of the eggs and the babies by herself, and may continue to feed the babies until they’re around six months old.

The kakapo eats nuts, seeds, fruit, leaves, and other plant material. Its legs are short but strong, and it will jog for long distances to find food. It can also climb really well, right up into the very tops of trees. It uses its strong legs and its large curved bill to climb. Then, to get down from the treetop more efficiently, the kakapo will spread its wings and parachute down, although its wings aren’t big enough or strong enough for it to actually fly. A big heavy male sort of falls in a controlled plummet while a small female will land more gracefully.

While the kakapo is doing a lot better now than it has in decades, it’s still critically endangered. The current population is 249 individuals according to New Zealand’s Department of Conservation. Scientists and volunteers help monitor the birds, especially newly hatched chicks. If a mother bird is having trouble finding enough food for all her babies, or if any of the babies appear sick or injured, a team of conservationists will decide if they need to help out. They sometimes move a chick from a nest where the mother bird has a lot of other babies to one where there are only one or two babies. Some chicks are raised in nurseries if necessary and reintroduced to the wild when they’re old enough.

The kakapo can live for a long time. This isn’t unusual for parrots, which can live as long as a human, but the kakapo is especially long-lived. There are reports of individuals who have reached 120 years old. This means that potentially, only six kakapo generations ago, the first East Polynesian sailors, ancestors of the modern Maori, became the first humans ever to set foot on the shores of New Zealand. And there were some weird parrots there.

This is what the male kakapo sounds like when it’s booming:

[booming call]

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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. 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 312: Little Bouncy Animals

Posted on by

Podcast: Play in new window | Download (Duration: 11:56 — 13.2MB)

Subscribe: RSS | More

Thanks to Zachary and Oran for this week’s topic, some little animals that bounce around like tiny kangaroos!

Further reading:

Evolution of Kangaroo-Like Jerboas Sheds Light on Limb Development

Supposedly extinct kangaroo rat resurfaces after 30 years

High-Speed Videos Show Kangaroo Rats Using Ninja-Style Kicks to Escape Snakes

Williams’s jerboa [picture by Mohammad Amin Ghaffari – https://www.inaturalist.org/photos/177950563, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=115769436]:

A drawing of a jerboa skeleton. LEGS FOR DAYS:

The San Quintin kangaroo rat lives! [photo from article linked above]

Show transcript:

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

This week we’re going to learn about two cute little animals suggested by Zachary and Oran! Both of these animals are rodents but although they look remarkably alike in some unusual ways, they’re not actually all that closely related.

First, Zachary suggested the jerboa. We talked about the pygmy jerboa in episode 136, but we haven’t talked about jerboas in general. It’s a small rodent that’s native to the deserts of Asia, north Africa, and the Middle East. It’s usually brown or tan with some darker shading on the back and tail. It looks sort of like a gerbil with long ears, long hind legs, and a tuft at the end of the tail. Its front legs are short and it has an adorable whiskery nose.

The reason the jerboa’s hind legs are so long while its front legs are really short is that it jumps around on its hind legs like a kangaroo. Not only can it jump really fast, up to 15 mph, or 24 km/h, it can change directions incredibly fast too. This helps it evade predators, because most animals are fastest when running in a straight line. The jerboa bounces in all sorts of directions, hopping or just running on its long hind legs, with its long tail held out for balance. It can also run on all fours with its short front legs helping it maneuver, but for the most part it’s a bipedal animal. It has tufts of stiff hairs under its toes that help it run through loose sand.

The jerboa eats plants, although sometimes if it finds a nice juicy insect it will eat it too. Mostly it just eats leaves, bulbs, roots, and some seeds. It gets all of the moisture it needs from its diet, which is good because it lives in the desert where there’s not much water available.

Some species of jerboa mainly eat insects and spiders, and some have short ears instead of long ears. This is the case for the thick-tailed pygmy jerboa that lives in parts of China, Mongolia, and Russia. Its head and body only measures about two inches long, or almost 5 cm, but its tail is twice that length. The reason it’s called a thick-tailed jerboa is because it stores fat at the base of its tail, which makes the tail look thick compared to many rodent tails.

The jerboa is mostly active at dawn and dusk, although some species are fully nocturnal. It spends the day in a burrow it digs in sand or dirt. A jerboa will usually have more than one burrow in its territory, with the entrances usually hidden under a bush or some other plant. Different burrows have different purposes. Some have numerous entrances and lots of side tunnels but are relatively shallow, which is useful if the jerboa lives in an area with a rainy season. A shallow burrow won’t flood if it rains a lot. Some burrows are temporary, which the jerboa may dig if it’s out and about during the day looking for food. A mother jerboa will dig a burrow with a roomy nesting chamber to raise her babies, and a jerboa’s winter burrow has a nesting chamber that’s deep underground to help it stay warm. Some species of jerboa construct unusual burrows, like the lesser Egyptian jerboa that has spiral-shaped burrows with storage chambers. Most jerboas are solitary animals, although sometimes a group will hibernate together in winter to help everyone stay warmer.

Scientists have been studying the jerboa to learn how different animals have evolved radically different leg lengths. The jerboa’s incredibly long hind legs are very different from its very short front legs, but it evolved from animals that had four short legs. But jerboas are born with four short legs, and as the babies grow up their hind legs grow longer and longer.

The jerboa is an incredibly efficient runner. Some species can jump as far as six feet in a single bound, or 1.8 meters, and up to three feet, or 90 cm, straight up.

The jerboa isn’t the only rodent that hops on its hind legs like a kangaroo. The kangaroo rat does too, and it’s Oran’s suggestion. Oran pointed out that a long time ago, I think in the humans episode, I said that humans are the only fully bipedal mammal, meaning we only ever walk on our hind legs. (Crawling when you’re a baby or trying to find something under the couch don’t count.) I was wrong about that for sure, because the kangaroo rat, the jerboa, and a few other mammals are also bipedal.

The kangaroo rat is native to parts of western North America. It looks a lot like a jerboa, with long hind legs and a long tail, although its ears are smaller. But the kangaroo rat and the jerboa aren’t closely related, although both are rodents. Their similarities are due to convergent evolution, since both animals live in very similar environments with the same selective pressures.

The largest species of kangaroo rat, the giant kangaroo rat, grows around 6 inches long, or 15 cm, with a tail about 8 inches long, or 20 cm. It can jump even longer than the jerboa although it doesn’t move as fast on average.

Like the jerboa, the kangaroo rat can change directions quickly, and it’s also mostly nocturnal and spends the day in a burrow. Some species spend almost all the time in burrows, only emerging for about an hour a night to gather seeds. Since owls like to eat kangaroo rats, you can’t blame them for wanting to stay underground as much as possible.

Snakes also like to eat kangaroo rats, especially the sidewinder rattlesnake. It’s a fast predator with venom that can easily kill a little kangaroo rat, but the kangaroo rat isn’t helpless. A study published in 2019 filmed interactions in the wild between the desert kangaroo rat and the sidewinder, using high-speed cameras. They had to use high-speed cameras because the snakes can go from completely unmoving to a strike in under 100 milliseconds. That’s less time than it takes you to blink. But the kangaroo rat can react in even less time, as little as 38 milliseconds after the snake starts to move. A lot of time the kangaroo rat will completely leap out of range of the snake, but if it can’t manage that, it will kick the snake with its long hind legs, which are strong enough to knock the snake away. Little fuzzy ninjas.

Unlike the jerboa, the kangaroo rat mostly eats seeds. The jerboa’s teeth aren’t very strong so it can’t bite through hard seeds, but the kangaroo rat’s teeth are just fine with seeds. The kangaroo rat also has cheek pouches, and it will carry lots of seeds home to its burrow. It keeps extra seeds in special burrow chambers called larders.

The kangaroo rat sometimes lives in colonies that can number in the hundreds, but it’s still a mostly solitary animal. It has its own burrow that’s separate from the burrows of other members of its colony, and it doesn’t share food or interact very much with its neighbors. It will communicate with other kangaroo rats by drumming its hind feet on the ground, including warning its neighbors to stay away and alerting them to predators in the area.

The kangaroo rat is vulnerable to habitat loss, since it mostly lives in desert grassland and humans tend to view that kind of land as useless and in need of development. An example of this is the San Quintin kangaroo rat, which is only found in western Baja California in Mexico. Only two large colonies were known when it was discovered by science in 1925, although it used to be much more widespread. But in the decades since 1925, the land was developed for agriculture until by 1986 the two colonies were completely wiped out. Scientists worried the species had gone extinct. Then, in 2017, a colony was discovered in a nature preserve and everyone breathed a sigh of relief. Other colonies have been discovered on farmland that has been abandoned due to drought. Still, the San Quintin kangaroo rat is critically endangered.

The kangaroo rat is actually helpful for the environment. Because it stores seeds underground, and sometimes forgets where it put them, it helps native plants spread. Its burrows help increase soil fertility and the spread of water through the soil. This is similar to the jerboa, which also eats enough insects to help reduce the number of agricultural pests in some areas.

There are also two species of kangaroo mouse, which are closely related to kangaroo rats. They mostly live in the state of Nevada in North America. There are also jumping mice that look like ordinary mice but with long hind legs. It also has cheek pouches. While some jumping mice live in western North America, some live in northeastern North America and Canada and are adapted to cold weather and long winters. One species of jumping mouse lives in the mountains in parts of China. There’s also a larger jumping rodent called the springhare that lives in parts of Africa, and which is about the size of a squirrel or a small rabbit. Like all these other rodents, it’s bipedal and hops on its hind legs like a little kangaroo, using its long tail for balance and to prop itself up when it’s standing. It mostly eats plants but will sometimes eat insects, and it spends most of the day in burrows. There’s also a hopping mouse native to Australia, which is a rodent with long hind legs and a long tail and long ears. It’s not closely related to the jerboa or the kangaroo rat, but it looks a lot like both because of convergent evolution. It mostly eats seeds.

All these animals are rodents, but Australia also has another animal called the kultarr that looks a lot like the kangaroo rat and the jerboa. It’s not a rodent, though. It’s actually a marsupial that’s completely unrelated to rodents although it looks like a rodent. That’s definitely what you call convergent evolution.

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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. 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 311: The Mystery Deep-Sea Spider

Posted on by

Podcast: Play in new window | Download (Duration: 7:53 — 8.7MB)

Subscribe: RSS | More

Thanks to Llewelly for this suggestion, and thanks to Dr. Thomas A. Hegna for providing me with the two papers I reference in this episode!

Images are taken from the papers.

The mystery “spider”:

Long-legged isopods:

Show transcript:

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

My carefully planned out episode schedule has already gotten messed up, but I got excited about this topic and couldn’t wait to share it! It’s a mystery invertebrate from the deep sea that has been solved! Thanks to Llewelly for bringing this to my attention, and thanks to arthropod paleontologist Dr. Thomas A. Hegna for posting this information on Mastodon in the first place, and for providing the relevant papers to me. People are pretty great.

I knew about this topic from the book The Search for the Last Undiscovered Animals by Karl Shuker, but I hadn’t been able to find out more. Until now.

In the late 1980s, a program called DISCOL 1 was launched to study disturbances on the sea floor due to underwater mining. It focused on the deep sea in the South Pacific. One of the things the expedition did was drop underwater cameras with bait tied to them. When an animal came to investigate the bait, the camera took pictures. I have a birdfeeder like this now although I don’t have to drop it anywhere.

In February 1989, the camera descended to about 13,600 feet, or 4,150 meters, in the Peru basin. When it was hauled up a few days later and the pictures retrieved, the scientists saw something they didn’t recognize on 20 of the photos. It looked like a spider.

The scientists were able to get a good idea of the animal’s size because they knew how big the bait was and how big the metal rod was that the bait was tied to. The animal’s body was about 2 and a half inches long, or 6 cm, and about half that width, not counting its long, jointed legs. It had five pairs of appendages, including three pairs of walking legs. The other two pairs of appendages were longer and might be feelers of some kind, with the front pair possibly used to manipulate food. The estimated legspan was almost 8 inches across, or more than 20 cm.

The scientists published a short article about the finding later in 1989 and proposed that the animal be tentatively placed in the phylum Arachnida with spiders and their relations. But this placement is a big deal, because there are no known spider relations that live in deep water. Some spiders have evolved to live in water at least part of the time, but they always have to have access to the air.

For a long time that’s all anyone knew. Most scientists thought the animal was probably a pycnogonid [pik-NA-gunid], an arthropod commonly called a sea spider although it’s not actually an arachnid. We talked about sea spiders in episode 105, so I’ll revisit some of the information from that episode.

Sea spiders live throughout the world’s oceans and there are well over a thousand known species. Most are small and live in shallow water, but a few live in water up to 23,000 feet deep, or 7,000 meters. The biggest species live in the cold waters around Antarctica, with the very largest individual ever found having a legspan of about 27 inches across, or 70 cm.

The sea spider has four pairs of legs, although a few species have five or six pairs of legs instead. Some species have one or two pairs of simple eyes, but other species have no eyes at all. The body is quite small in relation to the legs, which are extremely long, which means the digestive tract is actually partly in the legs, because the body is too small for it. It walks along the bottom of the ocean or may swim by pulsing its long legs like a jellyfish with legs instead of a bell. In species that swim, the legs may be lined with long bristles.

Some species have mouthparts, but most eat using a proboscis that it uses to suck fluids out of its prey. Some species have spines at the tip of the proboscis. It sticks its proboscis into a sponge, worm, jelly, sea anemone, or other invertebrate, injects digestive fluids that liquefy the surrounding tissues, and slurps the fluids up. Sometimes this kills the prey animal, sometimes it doesn’t.

All this does sound a lot like the spider-like animal photographed in 1989. But in 2004 a new paper was published about the animal, where the original scientists teamed with some other experts to re-examine the photographs. Their conclusion is that the mystery animal wasn’t a spider or a sea spider but something else: a munnopsidid isopod.

Isopods are crustaceans that have been around for at least 300 million years. They live all over the world, on land and in both fresh water and in the ocean. The animal sometimes called the woodlouse or pill bug or roly-poly or sow bug are actually isopods. All isopods have segmented exoskeletons, as you may have seen in roly-polies or whatever you call those little guys, and all have two pairs of antennae and seven pairs of jointed legs.

Isopods are very common animals in the ocean and the most common isopods are members of the family Munnopsidae. Most have short legs but some have long legs, including some species in the subfamily Bathyopsurinae.

While Munnopsids are common, there are only four species in two genera in Bathyopsurinae. The biggest isopods live in the deep sea and while these four species are pretty big, up to 2 and a half inches long, or 6 cm, they’re nowhere near the size of the largest isopods known. That would be the giant isopod that can grow up to 20 inches long, or 50 cm, but it’s not closely related to these four species.

As to which species the mystery isopod belongs to, the photographs aren’t close enough or clear enough for a definite identification. It’s possible the mystery isopod belongs to a species unknown to science.

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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. 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 310: The Crab-Eating Fox

Posted on by

Podcast: Play in new window | Download (Duration: 6:05 — 7.1MB)

Subscribe: RSS | More

Thanks to Dean for this week’s suggestion, the crab-eating fox!

Further reading:

Jaguars could prevent a not-so-great American biotic exchange

The crab-eating fox is not actually a fox:

Show transcript:

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

I’m happy to report that I’m feeling healthy and testing negative for covid now. Even my lingering cough has pretty much cleared up! I hope you’re healthy too. Anyway, this week let’s learn about an unusual animal suggested by Dean, the crab-eating fox.

The crab-eating fox lives in parts of South America east of the Andes Mountains. It likes forests and open woodlands, and sometimes lives in savannas too although it prefers areas with a lot of tree cover and rivers. It’s a fairly small animal that rarely weighs more than 18 pounds, or 8 kg, and stands about 16 inches tall at the shoulder, or 40 cm. It has a thick coat that’s mostly gray or brown with reddish ears and paws, black markings on the ears, tail, and legs, and a black stripe down its spine. It also has a bushy tail and a relatively short muzzle.

There are two important questions we need to answer about the crab-eating fox. First, does it actually eat crabs? Second, is it actually a fox?

The crab-eating fox does indeed eat crabs, although it’s an omnivore and will eat pretty much anything it can find. This includes insects, eggs, fruit, carrion, and small animals of various kinds, especially rodents. But during the wet season, when it rains a whole lot and rivers flood and ebb repeatedly, the crab-eating fox eats a whole lot of crabs and other crustaceans.

The crab-eating fox is not, in fact, a fox. It’s definitely related to foxes, since it’s a canid and the family Canidae includes foxes as well as wolves, dogs, coyotes, and all their relations, and it looks like a fox. It’s the only member of its own genus, but it’s grouped together with some other South American canids that look like foxes but are more closely related to wolves. But they’re not all that closely related to either foxes or wolves. Another member of this group is the maned wolf, the one with super long legs, which we talked about most recently in episode 167.

Scientists think that the crab-eating fox’s closest relation is another South American canid called the short-eared dog, which we talked about in episode 195. Unlike the crab-eating fox, the short-eared dog likes heavy forests and lives in the Amazon rainforest. We know so little about it that researchers sometimes refer to it as the ghost dog.

The crab-eating fox is nocturnal and spends most of the daytime sleeping in a den. Sometimes it makes a den by burrowing into thick grass, sometimes it will dig a burrow, but it prefers to find a den made by another animal and move into it if it’s empty. It may have several dens in its territory, which it often shares with its mate. Both parents help take care of the babies, and a female may have two litters a year.

I’m happy to report that the crab-eating fox is not endangered. It’s doing just fine in most places. It’s an adaptable, intelligent animal, which helps it thrive in a changing environment the same way coyotes do in North America. In fact, it fills the same ecological niche in South America that the coyote fills in North America, and this has led to a really weird potential problem.

The crab-eating fox is native to South America, but it has been spreading northward into Central America. Likewise, the coyote is native to North America, but it has been spreading southward into Central America. Neither species likes thick forested areas, but as more rainforests are cleared for agriculture and housing, people have inadvertently made a sort of corridor for both species. Having people around doesn’t bother either the crab-eating fox or the coyote. Coyotes have made it as far south as Panama, almost to South America.

If this continues, with crab-eating foxes migrating north and coyotes migrating south in ever greater numbers, eventually they’ll start to compete with each other. This isn’t good for either of them.

The only thing stopping coyotes from migrating farther south at this point is a thick strip of tropical forest called Darien National Park in Panama, where jaguars live. Unlike coyotes and crab-eating foxes, jaguars are very shy of humans and need a lot of dense forest to live in. This is exactly the kind of place that coyotes and crab-eating foxes like least, not to mention that a jaguar would be more than happy to catch and eat either species of canid. So as long as the forest in the national park remains intact, it acts as a barrier to keep both canid species apart, and that’s good. It’s also good for the jaguars and lots of other animals. Hooray for protected forests!

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. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. 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!