Episode 437: Updates 8 and the Nutria

Nicholas shared a paper with me that indicates that marsupials actually evolved in what is now Asia, with marsupial ancestors discovered in China. They spread into North America later. So I’ve been getting that wrong over many episodes, over several years.

Måns shared a correction from an older episode where I mentioned that humans can’t get pregnant while breastfeeding a baby. I’ve heard this all my life but it turns out it’s not true. It is true that a woman’s fertility cycle is suppressed after giving birth, but it’s not related to breastfeeding. Some women can become pregnant again only a few months after giving birth, while others can’t get pregnant again for a few years. It depends on the individual. That’s important, since the myth is so widespread that many women get pregnant by accident thinking they can’t since they’re still feeding a baby.

Warblrwatchr commented on the ultraviolet episode and mentioned that cats can see ultraviolet, which is useful to them because mouse urine glows in UV light.

Finally, Llewelly pointed out that in episode 416, I didn’t mention that fire ant venom isn’t delivered when the ant bites someone. The ant bites with its mandibles to hold on, then uses the stinger on its back end to sting repeatedly.

Now, let’s dive into some updates about animals we’ve talked about in past episodes. As usual, I don’t try to give an update on every single animal, because we’d be here all week if I did. I just chose interesting studies that caught my eye.

In episode 402, we talked about snakes that travel in unusual ways, like sidewinders. Even though I had a note to myself to talk about the brown tree snake in that episode, I completely forgot. The brown tree snake is native to parts of coastal Australia and many islands around Indonesia and Papua New Guinea. It’s not native to Guam, which is an island in the western Pacific, way far away from the brown tree snake’s home. But in the late 1940s, some brown tree snakes made their way to Guam in cargo ships and have become invasive since then.

The brown tree snake can grow up to six and a half feet long, or 2 meters, and is nocturnal, aggressive, and venomous. It’s not typically a danger to adults, but its venom can be dangerous to children and pets. The government employs trained dogs to find the snakes so they can be removed, and this has worked so well that brown tree snake population is declining rapidly on the island. But that hasn’t stopped the snake from driving many native animals to extinction in the last 75 years, especially birds.

One of the things scientists did in Guam to try and protect the native birds was to place smooth poles around the island so birds could nest on top but snakes couldn’t climb up to eat the eggs and chicks. But before long, the snakes had figured out a way to climb the poles, a method never before documented in any snake.

To climb a pole, the snake wraps its body around it, with the head overlapping the tail. Then it sort of scoots itself up the pole with tiny motions of its spine, a slow, difficult process that takes a lot of energy. Tests of captured brown tree snakes afterwards showed that not all snakes are willing or able to climb poles this way. Scientists think the brown tree snake evolved this method of movement to climb smooth-trunked trees in its native habitat. They also suspect some other species of snake can do the same.

Way back in episode 23 we talked about musical animals, including how some species can recognize and react to a rhythmic beat while most can’t. Sea lions are really good at it, especially a sea lion named Ronan.

Ronan was rescued in 2009 when she was a young sea lion suffering from malnutrition, wandering down a highway in California. She was determined to be non-releasable after she recovered, so she’s been a member of the Pinniped Lab in the University of California – Santa Cruz ever since, where she participates in activities that help scientists study sea lions. The rhythm studies are only one of the things she does, and only occasionally. The scientists put on a metronome and she bobs her head to the beat while they film her in ultra-slow motion.

The latest study was published in May of 2025. Ronan is 16 years old now and in her prime, so it’s not surprising that she performed even better than her last tests when she was still quite young. The study determined that not only does Ronan hit the beat right on time, she’s actually better at it than a human a lot of the time. She hits the beat within 15 milliseconds. When you blink your eye, it takes 150 milliseconds. If only she had hands, she’d be the best drummer ever!

The greatest thing about this process is that Ronan enjoys it. She’s rewarded with fish after a training session, and if she doesn’t feel like doing an activity, she doesn’t have to.

Back in episode 220, we talked about the giant panda, especially the mysterious Qinling panda that’s brown and tan instead of black and white. A study published in March of 2024 looked into the genetics of this unusual coat color and determined that it was a natural genetic mutation that doesn’t make the animals unhealthy, meaning it probably isn’t a result of inbreeding.

We talk occasionally about tool use in animals, especially in birds like crows and parrots, and in primates like chimpanzees. But a study published in November of 2024 detailed an elephant in the Berlin Zoo that uses a water hose to shower.

You may not think that’s a big deal, but the elephant in question, named Mary, uses the hose the way a human would to shower off. She holds the hose with her trunk just behind the nozzle, then moves it around and shifts her body to make sure she gets water everywhere she wants. She has to sling the hose backwards to clean her back, and when researchers gave her a heavier hose that she couldn’t move around as easily, she didn’t bother with it but just used her own trunk to spray water on herself.

Even more interesting, another elephant, named Anchali, who doesn’t get along with Mary, will interfere with the hose while Mary is using it. She lifts part of the hose to kink it and stop the water from flowing. Sometimes she even steps on the hose to stop the water, something the elephants have been trained not to do since zookeepers use hoses to clean out the enclosures. Anchali only steps on a hose if Mary is using it.

This is the first time researchers have studied a water hose as tool use, but it makes sense for elephants to understand how to use a hose, since they have a built-in hose on their faces.

We talked about the rhinoceros in episode 346, and more recently in the narwhals and unicorns episode. A study published in March of 2025 suggested that the Javan rhino should be classified as a new species of rhino in its own genus. The Javan rhino is incredibly rare, with only about 60 individuals alive in the world, all of them living in the wild in one part of Java. The Javan rhino is also called the Sundaic rhinoceros, and it’s been considered a close relation of the Indian rhinoceros. It’s smaller than the Indian rhino and most Javan rhino females either don’t have a horn at all or only have a big bump on the nose instead of a real horn.

The Javan rhino is so rare that we don’t really know much about it. The new study determined that there are big enough differences between the Javan rhino and the Indian rhino, in their skeletons, skin, diet, behavior, and fossil remains, that they should be placed in separate genera. The proposed new name for the Javan rhino is Eurhinoceros sondaicus instead of Rhinoceros sondaicus.

The only insect native to Antarctica is the Antarctic midge, which we mentioned in episode 221 but haven’t really talked about. It’s a flightless insect that can grow up to 6 mm long, and it’s the only insect that lives year-round in Antarctica. It’s only been found on the peninsula on the northwestern side of the continent.

Every animal that lives in Antarctica is considered an extremophile, and this little midge has some remarkable adaptations to its harsh environment. Its body contains compounds that minimize the amount of ice that forms in its body when the temperature plunges. It’s so well adapted to cold weather that it actually can’t survive if the temperature gets much above freezing. It eats decaying vegetation, algae, microorganisms, and other tiny food in its larval stages, but doesn’t eat at all as an adult.

The midge spends most of its life as a larva, only metamorphosing into its adult form after two winters. During its first winter it enters a dormant phase called quiescence, but as soon as the weather warms, it can resume development. It enters another dormant phase called obligate diapause for its second winter, where it pupates as soon as the weather gets cold. When summer arrives, all the midges emerge as adults at the same time, which allows them to find mates and lay eggs before dying a few days later.

The female midge lays her eggs and deposits a jelly-like protein on top of them. The jelly acts as antifreeze and keeps the eggs from drying out, and when the eggs hatch, the babies can eat the jelly.

In episode 384, we talked about the Komodo dragon, and only a month or so after that, and right after the 2024 updates episode, a new study was released about Komodo dragon teeth. It turns out that the Komodo dragon has teeth that are tipped with iron, which helps keep them incredibly sharp but also strong. As if Komodo dragons weren’t already scary enough, now we know they have metal teeth!

Many animals incorporate iron in their teeth, especially rodents, which causes some animals to have orange or partially orange teeth. In the Komodo dragon, the iron is incorporated into the tooth’s enamel coating, but only on the tips of the teeth. Since Komodo dragons have serrated teeth, that’s a lot of very sharp points.

There’s no way currently to test fossilized teeth to see if they once contained iron, especially since the iron would most likely be deposited in the tooth coating, the way it is for animals living today, not in the tooth itself. But because the Komodo dragon has teeth that are very similar in many ways to the teeth of meat-eating dinosaurs, scientists think some dinosaurs may have had iron in their teeth too.

And that brings us to the nutria, an animal suggested by Emerson. Emerson likes the nutria because of its orange teeth, and hopefully you can guess why its teeth are orange.

The nutria is also called the coypu, and it’s a rodent native to South America. In Spanish the word nutria means otter, so in South America it’s almost exclusively called the coypu, and the name coypu is becoming more popular in other languages too. It’s been introduced to other parts of the world as a fur animal, and it has become invasive in parts of Europe, Japan, New Zealand, and the United States.

The nutria is a semi-aquatic rodent that looks like a muskrat but is much bigger, up to two feet long, or 64 cm, not counting its tail. It also kind of looks like a beaver but is smaller. If you’re not sure which of these three animals you’re looking at, since they’re so similar, the easiest way to tell them apart is to look at their tails. The beaver has a famously flattened paddle-like tail, the muskrat’s tail is flattened side to side to act as a rudder, and the nutria’s tail is just plain old round. The nutria also has a white muzzle and chin, and magnificent white whiskers.

The nutria mostly eats water plants and is mostly active in the twilight. While it usually lives around slow-moving streams and shallow lakes, it will also tolerate saltwater wetlands. Wild nutrias are generally dark brown, but ones bred for their fur are often blond or even white.

The nutria digs large dens with the entrance usually underwater, but the nesting chamber inside is dry. It also digs for roots. This can cause a lot of damage to levees and riverbanks, which is why the nutria is so destructive as an invasive animal. It will also eat people’s gardens and commercial crops like rice and alfalfa.

One interesting thing about the nutria is that the female has teats that are high up on her sides, which allows her babies to nurse even when they’re all in the water.

The nutria’s big incisor teeth are bright orange, as we mentioned before. This is indeed because of the iron in the enamel that strengthens the teeth. Like other rodents, the nutria’s incisors grow throughout its life and are continually worn down as it chews tough plants. A nutria eats about 25% of its weight in plants every single day. That’s almost as much as me and pizza.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 435: The Narwhal and the Unicorn

Posted on June 2, 2025 by strangeanimalspodcast

Podcast: Play in new window | Download (Duration: 9:03 — 9.9MB)

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Thanks to Owen and Aksel, and Dylan and Emily for their suggestions this week!

Further reading:

Where did the unicorn myth come from?

The narwhal is my favorite whale:

Show transcript:

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

This week we’re going to look at an animal suggested by Owen and Aksel, and a related suggestion by Dylan and Emily.

Owen and Aksel suggested we talk about the narwhal, which we haven’t really discussed since episode 5 even though it’s one of my favorite animals. Dylan and Emily suggested we learn about animals that might have inspired legends of the unicorn. These two topics are definitely linked!

The narwhal is a toothed whale, but it doesn’t have very many teeth—in fact, most narwhals don’t have any teeth at all. It swallows its food whole and doesn’t need to chew, mostly small fish but also squid and other small animals. Male narwhals do have one tooth, a tusk that can be almost 10 feet long, or over 3 meters. The tusk is a spiral shape, developed from what would have been the left canine tooth, but instead of growing downward like a regular tooth, it grows forward, directly through the front of the lip. A lot of times people get confused and think the tusk is a horn that grows from the narwhal’s forehead, and that’s mainly because the narwhal is closely related to the unicorn legend.

That sounds weird at first, since the narwhal is a whale that can grow up to 18 feet long, or 5.5 meters, and lives in cold waters of the Arctic Circle. The unicorn is supposed to be a horse-like animal with a spiral horn growing from its forehead, although it’s also sometimes depicted as more goatlike in appearance, with cloven hooves and a little beard. It also usually has a long tail with a tuft at the end like a donkey or zebra.

In the olden days in Europe, the unicorn’s single spiral horn was supposed to have curative properties. If you ground up a little bit of the horn, known as alicorn, people thought it acted as a medicine to cure you of poisoning or other ailments. The alicorn was actually the tusk of the narwhal, but traders claimed it was a unicorn horn because they could charge more for it. The legend of the unicorn having a long spiral horn doesn’t come from ancient stories, it comes from the appearance of the narwhal’s tusk.

The narwhal is as mysterious as the unicorn in its own way. In fact, the narwhal seems a lot less plausibly real than a unicorn and a lot of people actually don’t realize it’s a real animal.

The biggest question about the narwhal is what its tusk is used for. Most males have one, and occasionally a male will grow two tusks. Most females don’t have one, although about 15% of females will grow a tusk, usually smaller than the male’s. Females live longer than males on average, so obviously the tusk isn’t helping males survive. Most scientists assume that it’s just a way for males to attract mates.

But the narwhal’s tusk seems to be useful for more than just decoration. It contains high concentrations of nerve endings, and scientists think it might help the whale sense a lot of information about the water around it. Narwhals have been observed smacking fish with their tusks to stun them, so that the whale can slurp them up more easily. And even though it’s technically a tooth, the narwhal’s tusk can bend up to a foot, or about 30 cm, in any direction without breaking.

The narwhal is pale gray in color with darker gray or brown dapples, but like gray horses, many narwhals get paler as they age. Old individuals can appear pure white. This can make them easy to confuse with another small whale that’s closely related, the beluga, which shares other characteristics with the narwhal. The beluga is white, has a small rounded head and doesn’t have a dorsal fin, and has a neck so that it can bend it head around. Most whales have lost the ability to move their heads. The beluga also lives in the same areas as the narwhal and both are the only two living members of the family Monodontidae. They even interbreed very rarely. But only the narwhal has a tusk.

One of the reasons why so many people believe the unicorn is a real animal is because it’s mentioned in some English-language versions of the Bible. When the Old Testament was first translated from Hebrew into Greek, the translators weren’t sure what animal the re’em was. It appeared in the texts a number of times but wasn’t described. The translators settled on monokeros for their translation, which in English is unicorn. These days, Biblical scholars translate re’em as a wild ox, or aurochs. You can learn more about the aurochs in episode 58, about weird cattle.

So while the Greek translators didn’t know what the re’em was, why did they decide it was a unicorn? It’s possible they were drawing on the writings of Greek physician Ctesias, from the fourth century BCE. Ctesias described an animal from India he called a type of wild ass, which had “a horn on the forehead which is about a foot and a half in length.” But it seems clear from his writing that he was describing a rhinoceros.

While the unicorn is mentioned in the Bible, it isn’t a specifically Christian legend. The karkadann is a huge monster in Muslim folk tradition, with a horn so big it could spear two or three elephants on it at the same time. In Siberia, some tribes told stories of a huge black ox with one horn, so big that when the animal was killed, the horn alone required its own sledge for transport. In some Chinese tales, the kilin was supposed to be a huge animal with one horn. For more information about the kilin, you can listen to episode 61.

It’s probable that all these stories stem from the rhinoceros, which we talked about in episode 346. Basically, it’s a big, heavy animal with relatively short legs, a big head that it carries low to the ground like a bison, and at least one horn that grows on its nose. It’s usually gray or gray-brown in color with very little hair, and its skin is tough. It eats plants.

The rhinoceros is actually most closely related to the horse and the tapir, which are odd-toed ungulates. The rhino has three toes on each foot, with a little hoof-like nail covering the front of each toe, but the bottom of the rhino’s foot is a big pad similar to the bottom of an elephant’s foot.

The rhino’s nose horn isn’t technically a horn because it doesn’t have a bony core. It’s made of long fibers of keratin all stuck together, and keratin is the same protein that forms fingernails and hair. It’s not an elegant spiral horn like the unicorn is supposed to have, and the rhino itself isn’t a delicate horse-like animal. It’s big and strong and can be extremely dangerous—but the original unicorn stories said it was a huge, fearsome beast.

In the 13th century, the Italian explorer Marco Polo visited Asia and saw a unicorn. He wrote later that “it is a hideous beast to look at, and in no way like what we think and say in our countries.” He probably saw a rhinoceros, so the unicorn legend and real life rhinos have been disappointing people for more than seven centuries.

Thanks for listening!

Episode 346: The Rhinoceros!

Posted on September 18, 2023 by strangeanimalspodcast

Podcast: Play in new window | Download (Duration: 10:33 — 11.8MB)

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Thanks to Mia for suggesting the black rhino this week! We’ll also learn about other rhinos and their relations, including a mystery rhino.

Further reading:

Photos suggest rhino horns have shrunk over past century

The Blue Rhinoceros – In Quest of the Keitloa

A rhino with a very small third horn:

Some rhinos have really big second horns [photo by David Clode and taken from this site]:

The “blue rhinoceros,” or keitloa, as illustrated in the mid-19th century:

Show transcript:

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

This week we’re going to talk about an animal I can’t believe we haven’t covered before. Thanks to Mia for suggesting the rhinoceros, specifically the black rhino! We’ll also learn about a mystery rhino.

We’ve talked about elephants lots of times, hippos quite a few times, and giraffes a couple of times, but pretty much the only episodes where we discussed a rhinoceros were 5 and 256. Episode 256 was mostly about mammoths, although we talked very briefly about the woolly rhinoceros, while episode 5 was about the unicorn and didn’t actually specifically talk about the rhino. So after almost 350 episodes of this podcast, one of the most amazing animals alive is one we literally haven’t learned about! Let’s fix that now.

Most people are pretty familiar with what a rhinoceros looks like. Basically, it’s a big, heavy animal with relatively short legs, a big head that it carries low to the ground like a bison, and at least one horn that grows on its nose. It’s usually gray or gray-brown in color with very little hair, and its skin is tough. It eats plants.

The rhinoceros isn’t related to the elephant or the hippopotamus. It’s actually most closely related to the horse and the tapir, which are odd-toed ungulates. The rhino has three toes on each foot, with a little hoof-like nail covering the front of each toe, but the bottom of the rhino’s foot is a big pad similar to the bottom of an elephant’s foot.

The rhino’s nose horn isn’t technically a horn because it doesn’t have a bony core. It’s made of long fibers of keratin all stuck together, and keratin is the same protein that forms fingernails and hair. That makes it even weirder that some people think a rhinoceros horn is medicine. It’s literally the same protein as fingernails, and no one thinks of fingernails are medicine. The use of rhinoceros horn as medicine isn’t even all that old. Ancient people didn’t think it was medicine, but some modern people do, and they’ll pay a whole lot of money for part of a rhino horn to grind up and eat. Seriously, they might as well be eating ground-up fingernails. (That’s gross.)

Because rhino horns are so valuable, people will kill rhinos just to saw their horns off to sell. That’s the main reason why most species of rhino are so critically endangered, even though they’re protected animals. Sometimes conservationists will sedate a wild rhino and saw its horn off, so that poachers won’t bother to kill it. A 2022 study determined that the overall size of rhino horns has shrunk over the last century, probably for the same reason that many elephants now have overall smaller tusks. Poachers are more likely to kill animals with big horns, which means animals with smaller horns are more likely to survive long enough to breed.

The species of rhinoceros alive today are native to Africa and Asia, but it used to be an animal found throughout Eurasia and North America. It’s one of the biggest animals alive today, but in the past, some rhinos were even bigger. We’ve talked about Elasmotherium before, which lived in parts of Eurasia as recently as 39,000 years ago. It had long legs and could probably gallop like a horse, but it was the size of a mammoth. It also probably had a single horn that grew in the middle of its forehead, which is why it’s sometimes called the Siberian unicorn.

We’ve also talked about Paraceratherium before. It was one of the biggest land mammals that ever lived, and while it didn’t have a horn, it was a type of rhinoceros. It lived in Eurasia between about 34 and 23 million years ago, and it probably stood about 16 feet tall at the shoulder, or 5 meters. The tallest giraffe ever measured was 19 feet tall, or 5.88 meters, at the top of its head. Paraceratherium had a long neck, possibly as much as eight feet long, or 2.5 meters, but it would have held its neck more or less horizontal most of the time. It spent its time eating leaves off of trees that most animals couldn’t reach, and when it raised its head to grab a particularly tasty leaf, it was definitely taller than the tallest giraffe, and taller than any other mammal known.

While rhinos are famous for their horns, not every rhinoceros ancestor had a horn. But because rhino horns are made of keratin and not bone, we don’t always know if an extinct species had a horn. Most of the time the horns rotted away without being preserved. We do know that some ancient rhinos had a pair of nose horns that grew side by side, that some had a single nose horn or forehead horn, that some had both a nose horn and a forehead horn, and that some definitely had no horns at all.

The rhinos alive today have either one or two horns. The Indian rhinoceros has one horn on its nose, and the closely related Javan rhino also only has one horn. The Sumatran rhino has two horns, as do the white rhino and the black rhino. Sometimes an individual rhino will develop an extra horn that grows behind the other horn or horns and is usually very small. This is extremely rare and seems to be due to a genetic anomaly. There are even reports of rhinos that have four horns, all in a row, but the extra ones, again, are very small.

Mia specifically wanted to learn about the black rhino. It and the white rhino are native to Africa. You might think that the white rhino is pale gray and the black rhino is dark gray, but that’s actually not the case. They’re both sort of a medium gray in color and they’re very closely related. It’s possible that the word “white” actually comes from the Dutch word for “wide,” referring to the animal’s wide mouth. The black rhino has a more pointed lip that looks a little bit like a beak.

One interesting thing about the black and white rhinos is that neither species has teeth in the front of its mouth. It uses its lips to grab plants instead of its front teeth, and then it uses its big molars to chew the plants. The white rhino mostly eats grass while the black rhino eats leaves and other plant material.

A big male black rhino can stand over 5 1/2 feet tall at the shoulder, or 1.75 meters, and is up to 13 feet long, or 4 meters. It can weigh as much as 4,000 lbs, or 1,800 kg. This sounds huge and it is, but it’s actually smaller than the white rhino, which is the biggest rhino alive today. A big male white rhino can stand over 6 1/2 feet tall at the shoulder, or 2 meters, can be 15 feet long, or 4.6 meters, and can weigh up to 5,300 lbs, or 2,400 kg. These are really really big animals. Nothing much messes with the rhino because it’s so big and heavy, its skin is so tough, and it can do a lot of damage with its horn if it wants to. The rhino doesn’t see very well, but it has good hearing and a good sense of smell.

The nose horn is always the bigger one in species that have two horns, and in the black rhino it can grow quite long. One nose horn was measured as being over 4 1/2 feet long, or 1.4 meters, although most are only about 20 inches long, or 50 cm. The rear horn, which grows roughly over the eyes, is about half the length of the front horn, and is sometimes no more than a little bump. But some black rhinos found in South Africa have a rear horn that’s at least as long as the front horn, and sometimes longer, and that brings us to our mystery rhino.

A rhino with this trait is referred to as a keitloa, a word taken from the Tswana language spoken in the area. In the 19th century, the keitloa was referred to by European colonizers as the blue rhinoceros. The blue rhino wasn’t blue, but it was considered quite rare and different from the ordinary black rhino. It was supposed to be bigger and and even more solitary than the black rhino.

Until 1881, many scientists thought the keitloa was a separate species of rhino from the black rhino, which it otherwise resembled. In 1881, though, a study of black rhinos and blue rhinos determined that they were the same species. A century later, in 1987, scientists found that black rhinos with better access to water grew larger horns than black rhinos living in dryer areas.

There are a number of subspecies of black rhino recognized by scientists, some of them still alive today and some driven recently to extinction. Some people still think that the keitloa may be a separate subspecies of black rhino. That’s one of many reasons why it’s so important to protect all rhinoceroses and their habitats, so we can learn more about these amazing animals.

Thanks for listening!

Episode 005: The Unicorn

Posted on March 6, 2017 by strangeanimalspodcast

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Everyone knows the legend of the unicorn and most of us know unicorns don’t really exist. But how did the legend get started? And more importantly, can we talk about narwhals a whole lot? Narwhals are rad.

Narwhal. So rad.

I haven’t seen this show but apparently it’s pretty good. I love that elasmotherium.

Unicorns are (sort of) real. Unicorning certainly is.

Thanks to Jen and Dave for suggesting this week’s topic!

Show transcript:

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

This week’s episode is about the unicorn, or at least about almost-unicorns. This is a re-record of the original episode to improve sound quality and update some information.

When I was a kid, I was convinced unicorns were real. I’m not alone in this, apparently. A lot of people assume the unicorn is a real animal. Take away the magical trappings and it’s just a horse-like animal with one spiral horn. It seems a lot more plausible than squids, for instance.

I’m sorry to tell you that that kind of unicorn doesn’t exist, and never has, or at least we have no fossil or subfossil evidence that an animal resembling the classical unicorn actually existed. But the animals that probably inspired the unicorn legend are fascinating.

Everyone knows that the unicorn has one spiral horn growing from its forehead. The horn was supposed to have curative properties. If you ground up a little bit of the horn, known as alicorn, it acted as a medicine to cure you of poisoning or other ailments. If you actually made a little cup out of alicorn, you could drink from it safely knowing any poison was already neutralized. People in the olden days were really worried about being poisoned, probably because they didn’t understand how food safety and bacteria worked and they didn’t have refrigerators or meat thermometers and so forth. I suspect a lot of so-called poisoning cases were actually food poisoning. But this re-record is already off the rails, so back we get to the main topic.

All this about alicorn wasn’t legend, either. You could buy alicorn from apothecaries up until the late 18^th century. Doctors prescribed it. It was expensive, though—literally worth its weight in gold. Pharmacies kept their alicorns on display but chained down so no one could steal them.

The alicorn, of course, was actually the tusk of the narwhal, and the narwhal is as mysterious as the unicorn in its own way. In fact, the narwhal seems a lot less plausibly real than a unicorn and a lot of people actually don’t realize it’s a real animal. I had that discussion with a coworker last year and had a lot of fun astonishing her with science facts, or maybe boring her. It’s a fairly small whale, some 13 to 18 feet in length not counting the tusk. That’s about four to five and a half meters long. It’s pale gray in color with darker gray or brown dapples, but like gray horses, many narwhals get paler as they age. Old individuals can appear pure white.

The narwhal and the beluga whale are similar in size and physical characteristics, such as their lack of a dorsal fin. They live in the same areas and are the only two living members of the family Monodontidae. They even interbreed very rarely.

But the narwhal is the one with the horn, or more accurately a tusk. It’s not a horn at all but a tooth. Most males and about 15% of females grow a tusk. Occasionally an individual grows two tusks, but almost always it’s the left canine tooth that pierces through the lip and continues to grow, sometimes up to ten feet long, or 3 meters.

It’s a weird, weird tooth too. It can bend as much as a foot without breaking, or 30 cm, not something teeth are generally known for. It also grows in a spiral. And we still don’t know what the narwhal uses its tusk for.

For a long time, researchers assumed that male narwhals used their tusks the same way male deer use their antlers, to show off for females and to battle other males. Males do exhibit behavior called tusking, where two individuals will rub their tusks together in what researchers once assumed was a ritual fight display. But that seems not to be the case.

A 2005 study discovered that the tusk is filled with nerves and is extremely sensitive. Through its tusk, the whale can identify changes in water temperature and pressure, water salinity, and the presence of fish and other whales. It even acts as an antenna, amplifying sound. The study was led by Martin Nweeia of the Harvard School of Dental Medicine. Nweeia is a dentist, basically, which delights me. Okay, he’s a clinical instructor in restorative dentistry and biomaterials scientist, but dentist is funnier.

I liked Nweeia even more when I found this quote: “Why would a tusk break the rules of normal development by expressing millions of sensory pathways that connect its nervous system to the frigid arctic environment?” As someone who has trouble biting ice cream without wincing, I agree.

In other words, the narwhal’s tusk has scientists baffled. You hear that a lot in a certain type of article, but in this case it’s true. Especially baffling in this case is why the tusk is found mostly in males. If having a tusk confers some advantage in the narwhal’s environment, why don’t all or most females grow one too? If having a tusk does not confer an advantage beyond display for females, why does the tusk act as a sensory organ?

The narwhal lives in the Arctic, especially the Canadian Arctic and around Greenland, and it’s increasingly endangered due to habitat loss, pollution, and noise pollution. Overall increased temperature of the earth due to climate change has caused a lot of the sea ice to melt in their traditional breeding grounds, and then humans decided those areas would make great oil drilling sites. The noise and pollution of oil drilling and exploration threatens the narwhal in particular, since when a company searches for new oil deposits it sets off undersea detonations that can deafen or even outright kill whales. But it’s hard to count how many narwhals are actually alive, and some recent studies have suggested that there may be more around than we thought. That’s a good thing. Now we just have to make sure to keep them safe, because narwhals are awesome.

The narwhal eats fish and squid and shrimp and sometimes accidentally rocks, because instead of biting its prey the narwhal just hoovers it up, frequently from the sea floor, and swallows it whole. It does that because it doesn’t actually have any teeth. Besides the one.

As a final narwhal mystery, on December 17, 1892, sailors aboard a ship in the Dundee Antarctic Expedition spotted a single-horned narwhal-like whale in the Bransfield Strait. But narwhals don’t live in the Antarctic…as far as we know.

One of the reasons why so many people believe the unicorn is a real animal is because it’s mentioned in some English-language versions of the Bible. When the Old Testament was first translated from Hebrew into Greek in the third century BCE, the translators weren’t sure what animal the re’em was. It appeared in the texts a number of times but wasn’t described. The translators settled on monokeros for their translation, which in English is unicorn. The King James Version of the Bible mentions the unicorn seven times, giving it a respectability that other animals (like squids) can’t claim.

These days, Biblical scholars translate re’em as a wild ox, or aurochs. You can learn more about the aurochs in episode 58, Weird Cattle. The aurochs was the ancestor to domestic cattle and was already extinct in most parts of the world by the third century BCE, but lived on in the remote forests north of the Alps until its final extinction in 1627.

In fact, any description of a rhino given by someone who hasn’t actually seen one, just heard about it, comes across as a unicorn-like animal. So it’s quite likely that the translators made a wild guess that the fierce re’em was a rhinoceros, which they would have known as a horse-like animal with one horn.

But while the unicorn is mentioned in the Bible, it isn’t a specifically Christian legend. The karkadann is a huge monster in Muslim folk tradition, with a horn so big it could spear two or three elephants on it at the same time. In Siberia, some tribes told stories of a huge black ox with one horn, so big that when the animal was killed, the horn alone required its own sledge for transport. In some Chinese tales, the kilin was supposed to be a huge animal with one horn. For more information about the kilin, or kirin, you can listen to episode 61.

It’s probable that all these stories stem from the rhinoceros, which is a distinctive and unusual animal that we only take for granted today because we can go visit it in zoos. But some researchers have suggested a more exotic animal.

Elasmotherium was an ice age animal sometimes called the steppe rhino, giant rhino, or Siberian unicorn. The largest of the three species of elasmotherium was the size of a mammoth, some seven feet tall at the shoulder, or 2.1 meters. It was a grazer like horses and cattle today, and like them it had long legs, much longer than living rhinos. It could probably gallop at a pretty good clip. It lived at the same time as the smaller woolly rhino, but while the woolly rhino resembled modern rhinos in a lot of respects, notably its large horn on the nose with a smaller horn farther up, elasmotherium only had one horn…one enormous horn. On its forehead.

We don’t actually have any elasmotherium horns to look at. Rhino horns aren’t true horns at all but a keratin structure. Keratin is an interesting fiber. It can be immensely tough, as it is when it forms rhinoceros horns, but it’s also what our nails and hair are made of. It doesn’t fossilize any more than hair fossilizes. The main reason we know elasmotherium had a horn is because of its skull. While rhino horns are made of keratin fibers instead of bone, the skull shows a protuberance with furrows where blood vessels were that fed the tissues that generated the horn. In elasmotherium, the protuberance is five inches deep, or 13 cm, and three feet in circumference, or just over a meter. Researchers think the horn may have been five or six feet long, or 1.5 to 1.8 meters.

Researchers have also found an elasmotherium fossil with a partially healed puncture wound. It’s possible the males sparred with their enormous horns and sometimes inflicted injuries. At least it happened once.

For a long time researchers thought elasmotherium died out 350,000 years ago, much too long ago for humans to have encountered it. But a skull found a few years ago in Kazakhstan was radiocarbon dated to about 29,000 years old. If elasmotherium and humans did cross paths, it wouldn’t be at all surprising that the animal figured in stories that have persisted for millennia. More likely, though, our early ancestors found carcasses partially thawed from the permafrost the way mammoth carcasses are sometimes found today. This might easily have happened at the end of the Pleistocene, a relatively recent 11,000 years ago or thereabouts. A frozen carcass would still have a horn, and while the carcasses are long gone now, it’s not unthinkable that stories of a massive animal with a monstrous single horn were passed down to the present.

Of course, this is all conjecture. It’s much more likely that the stories are not that old and are about the modern rhinoceros. But it’s definitely fun to think about our ancestors crossing a vast hilly grassland for the first time in search of new hunting grounds, and coming across a herd of towering monsters with five-foot horns on their foreheads. That would definitely make an impression on anyone.

One final note about the unicorn. When I was a kid, I read a book called A Grass Rope by William Maine, published in 1957 so already an oldie when I found it in my local library. It concerns a group of Yorkshire kids who hunt for a treasure of local legend, which involves a unicorn. I was an American kid from a generation after the book was written, so although it’s set in the real world it felt like a fantasy novel that I could barely understand. When one of the characters discovers a unicorn skull, it didn’t seem any more extraordinary to me than anything else. But on rereading the book in my late teens, I was struck by a character at the end who tells the children “it’s not very hard to grow unicorns.”

By that time, I pretty much had Willy Ley’s animal books memorized, including the chapter about unicorns. In it, he talks about unicorning animals that have two horns.

The practice of unicorning has been known for centuries in many cultures, but the first modern experiment was conducted in 1933 by Dr. Franklin Dove in Maine. He removed the horn buds from a day-old bull calf and transplanted them to the middle of the calf’s forehead. The calf grew up, the horn buds took root and grew into a single horn that was almost completely straight and which sprouted from the bull’s forehead.

Dr. Dove reported that the bull was unusually docile, although I suspect his docility may have come from being handled more than the usual bull calf, so he became tamer than most bulls. Either way, the experiment proved that unicorning wasn’t difficult. Any animal that grows true horns, such as sheep, goats, and cattle, can be unicorned.

More recently, in the 1980s, neopagan writer Oberon Zell Ravenheart and his wife Morning Glory unicorned mohair goats that looked astonishingly like the unicorns of legend. So technically, kid me was right. Unicorns are sort of real.

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 at patreon.com/strangeanimalspodcast if you’d like to support us and get twice-monthly bonus episodes for as little as one dollar a month.

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Strange Animals Podcast

A podcast about living, extinct, and imaginary animals!

Tag Archives: rhinoceros

Episode 437: Updates 8 and the Nutria

Episode 435: The Narwhal and the Unicorn

Episode 346: The Rhinoceros!

Episode 005: The Unicorn