Episode 318: The Mysterious Malagasy Hippo

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 135: Smallest of the Large

This week we’re looking at some very small animals–but not animals that we think of as small. Join us for a horrendously cute episode!

Further reading:

The Echinoblog

Further listening:

Animals to the Max episode #75: The Sea Panda (vaquita)

Varmints! episode #49: Hippos

Further watching:

An adorable baby pygmy hippo

The Barbados threadsnake will protecc your fingertip:

Parvulastra will decorate your thumbnail:

Berthe’s mouse lemur will defend this twig:

The bumblebee bat will eat any bugs that come near your finger:

The vaquita, tiny critically endangered porpoise:

The long-tailed planigale is going to steal this ring and wear it as a belt:

He höwl:

A pygmy hippo and its mother will sample this grass:

This Virgin Islands dwarf gecko will spend this dime if it can just pick it up:

Show transcript:

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

I talk a lot about biggest animals on this podcast, so maybe it’s time to look at the very smallest animals. I don’t mean algae or bacteria or things like that, I mean the smallest species of animals that aren’t usually considered especially small.

We’ll start with the smolest snek, the Barbados threadsnake. It only lives on a few islands in the Caribbean, notably Barbados. The very largest individual ever measured was only 4.09 inches long, or 10.4 cm, but most are under four inches long. But it’s an extremely thin snake, not much thicker than a spaghetti noodle.

The Barbados threadsnake mostly eats termites and ant larvae. It spends most of its time in leaf litter or under rocks, hunting for food. The female only lays one single egg, but the baby is relatively large, about half the mother’s length when it hatches.

That’s so cute. Why are small things so cute?

Remember the starfish episode where we talked about the largest starfish? Well, what’s the smallest starfish? That would be Parvulastra parvivipara, which is smaller than a fingernail decoration sticker. It grows to about ten millimeters across and is orangey-yellow in color. It lives on the coast of Tasmania in rock pools between low and high tide, called intertidal rock pools.

If you remember the Mangrove killifish from a few episodes ago, you’ll remember how killifish females are hermaphrodites that produce both eggs and sperm, and usually self-fertilize their eggs to produce tiny clones of themselves. Well, Parvulastra does that too, although like the killifish it probably doesn’t always self-fertilize its eggs. But then it does something interesting for a starfish. Instead of releasing its eggs into the water to develop by themselves, Parvulastra keeps the eggs inside its body. And instead of the eggs hatching into larvae, they hatch into impossibly tiny miniature baby starfish, which the parent keeps inside its body until the baby is big enough to survive safely on its own.

But what do the baby starfish eat while they’re still inside the mother? Well, they eat their SIBLINGS. The larger babies eat the smaller ones, and eventually leave through one of the openings in the parent’s body wall, called gonopores. Researchers theorize that one of the reasons the babies leave the parent is to escape being eaten by its siblings. And yes, occasionally a baby grows so big that it won’t fit through the gonopores. So it just goes on living inside the parent.

Next, let’s look at the smallest primate. The primate order includes humans, apes, monkeys, and a lot of other animals, including lemurs. And the very smallest one is Berthe’s mouse lemur. Its body is only 3.6 inches long on average, or 9.2 cm, with a tail that more than doubles its length. Its fur is yellowish and brownish-red.

Berthe’s mouse lemur was only discovered in 1992. It lives in one tiny area of western Madagascar, where it lives in trees, which means it’s vulnerable to the deforestation going on all over Madagascar and is considered endangered.

It mostly eats insects, but also fruit, flowers, and small animals of various kinds. Its habitat overlaps with another small primate, the gray mouse lemur, but they avoid each other. Madagascar has 24 known mouse lemur species and they all seem to get along well by avoiding each other and eating slightly different diets. Researchers discover new species all the time, including three in 2016.

Last October we had an episode about bats, specifically macrobats that have wingspans as broad as eagles’. But the smallest bat is called the bumblebee bat. It’s also called Kitti’s hog-nosed bat, but bumblebee bat is way cuter. It’s a microbat that lives in western Thailand and southeast Myanmar, and like other microbats it uses echolocation to find and catch flying insects. Its body is only about an inch long, or maybe 30 millimeters, although it has a respectable wingspan of about 6 ½ inches, or 17 cm. It’s reddish-brown in color with a little pig-like snoot, and it only weighs two grams. That’s just a tad more than a single Pringle chip weighs.

Because the bumblebee bat is so rare and lives in such remote areas, we don’t know a whole lot about it. It was only discovered in 1974 and is increasingly endangered due to habitat loss, since it’s only been found in 35 caves in Thailand and 8 in Myanmar, and those are often disturbed by people entering them. The land around the caves is burned every year to clear brush for farming, which affects the bats too.

The bumblebee bat roosts in caves during the day and most of the night, only flying out at dawn and dusk to catch insects. It rarely flies more than about a kilometer from its cave, or a little over half a mile, but it does migrate from one cave to another seasonally. Females give birth to one tiny baby a year. Oh my gosh, tiny baby bats.

So what about whales and dolphins? You know, some of the biggest animals in Earth’s history? Well, the vaquita is a species of porpoise that lives in the Gulf of California, and it only grows about four and a half feet long, or 1.4 meters. Like other porpoises, it uses echolocation to navigate and catch its prey. It eats small fish, squid, crustaceans, and other small animals.

The vaquita is usually solitary and spends very little time at the surface of the water, so it’s hard to spot and not a lot is known about it. It mostly lives in shallow water and it especially likes lagoons with murky water, properly called turbid water, since it attracts more small animals.

Unfortunately, the vaquita is critically endangered, mostly because it often gets trapped in illegal gillnets and drowns. The gillnets are set to catch a different critically endangered animal, a fish called the totoaba. The totoaba is larger than the vaquita and is caught for its swim bladder, which is considered a delicacy in China and is exported on the black market. The vaquita’s total population may be no more than ten animals at this point, fifteen at the most, and the illegal gillnets are still drowning them, so it may be extinct within a few years. A captive breeding plan was tried in 2017, but porpoises don’t do well in captivity and the individuals the group caught all died. Hope isn’t lost, though, because vaquita females are still having healthy babies, and there are conservation groups patrolling the part of the Gulf of California where they live to remove gill nets and chase off fishing boats trying to set more of the nets.

If you want to learn a little more about the vaquita and how to help it, episode 75 of Corbin Maxey’s excellent podcast Animals to the Max is an interview with a vaquita expert. I’ll put a link in the show notes.

Next, let’s talk about an animal that is not in danger of extinction. Please! The long-tailed planigale is doing just fine, a common marsupial from Australia. So, if it’s a marsupial, it must be pretty big—like kangaroos and wallabies. Right? Nope, the long-tailed planigale is the size of a mouse, which it somewhat resembles. It even has a long tail that’s bare of fur. It grows to 2 ½ inches long not counting its tail, or 6.5 cm. It’s brown with longer hind legs than forelegs so it often sits up like a tiny squirrel. Its nose is pointed and it has little round mouse-like ears. But it has a weird skull.

The long-tailed planigale’s skull is flattened—in fact, it’s no more than 4 mm top to bottom. This helps it squeeze into cracks in the dry ground, where it hunts insects and other small animals, and hides from predators.

The pygmy hippopotamus is a real animal, which I did not know until recently. It grows about half the height of the common hippo and only weighs about a quarter as much. It’s just over three feet tall at the shoulder, or 100 cm. It’s black or brown in color and spends most of its time in shallow water, usually rivers. It’s sometimes seen resting in burrows along river banks, but no one’s sure if it digs these burrows or makes use of burrows dug by other animals. It comes out of the water at night to find food. Its nostrils and eyes are smaller than the common hippo’s.

Unlike the common hippo, the pygmy hippo lives in deep forests and as a result, mostly eats ferns, fruit, and various leaves. Common hippos eat more grass and water plants. The pygmy hippo seems to be less aggressive than the common hippo, but it also shares some behaviors with its larger cousins. For instance, the pooping thing. If you haven’t listened to the Varmints! Episode about hippos, you owe it to yourself to do so because it’s hilarious. I’ll put a link in the show notes to that one too. While the hippo poops, it wags its little tail really fast to spread the poop out across a larger distance.

Also like the common hippo, the pygmy hippo secretes a reddish substance that looks like blood. It’s actually called hipposudoric acid, which researchers thinks acts as a sunscreen and an antiseptic. Hippos have delicate skin with almost no hair, so its skin dries out and cracks when it’s out of water too long.

The pygmy hippo is endangered in the wild due to habitat loss and poaching, but fortunately it breeds successfully in zoos and lives a long time, up to about 55 years in captivity. For some reason females are much more likely to be born in captivity, so when a male baby is born it’s a big deal for the captive breeding program. I’ll put a link in the show notes to a video where you can watch a baby pygmy hippo named Sapo and his mother. He’s adorable.

Finally, let’s finish where we started, with another reptile. The smallest lizard is a gecko, although there are a lot of small geckos out there and it’s a toss-up which one is actually smallest on average. Let’s go with the Virgin Islands dwarf gecko, which lives on three of the British Virgin Islands. It’s closely related to the other contender for smallest reptile, the dwarf sphaero from Puerto Rico, which is a nearby island, but while that gecko is just a shade shorter on average, it’s much heavier.

The Virgin Islands dwarf gecko is only 18 mm long not counting its tail, and it weighs .15 grams. A paperclip weighs more than this gecko. It’s brown with darker speckles and a yellow stripe behind the eyes. Females are usually slightly larger than males. Like other geckos, it can lose its tail once and regrow a little stump of a tail.

The Virgin Islands dwarf gecko lives in dry forests and especially likes rocky hills, where it spends a lot of its time hunting for tiny animals under rocks. We don’t know a whole lot about it, but it does seem to be rare and only lives in a few places, so it’s considered endangered. In 2011 some rich guy decided he was going to release a bunch of lemurs from Madagascar onto Moskito Island, one of the islands where the dwarf gecko lives. Every conservationist ever told him oh NO you don’t, rich man, what is your problem? Those lemurs will destroy the island’s delicate ecosystem, drive the dwarf gecko and many other species to extinction, and then die because the habitat is all wrong for lemurs. So Mr. Rich Man said fine, whatever, I’ll take my lemurs and go home. And he did, and the dwarf gecko was saved.

Look, if you have so much money that you’re making plans to move lemurs halfway across the world because you think it’s a good idea, I can help take some of that money off your hands.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!