Tag Archives: rhinoceros

Episode 346: The Rhinoceros!

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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.

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 005: The Unicorn

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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 18th 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.

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.

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.

Thanks for listening!