Episode 369: Animals and Ultraviolet Light

Sorry to my Patreon subscribers, since this is mostly a rerun episode from April 2019. It’s a fun one, though!

The teensy pumpkin toadlet [photo by Diogo B. Provete – http://calphotos.berkeley.edu, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=6271494]:

The electromagnetic spectrum. Look how tiny the visible light spectrum is on this scale! [By NASA – https://science.nasa.gov/ems/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=97302056]:

Show transcript:

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

This was supposed to be the 2023 discoveries episode, but not only have I had a really busy week that’s kept me from finishing the research, I’m also coming down with a cold. My voice still sounds okay right now but considering how I feel, it’s not going to sound good for long, and I need to finish the March Patreon episode too! I decided to rerun a very old Patreon episode this week to allow me time to finish the March Patreon episode before my voice turns into an unintelligible croak. I did drop in some fresh audio to correct a mistake I made in the original episode and add some new information.

This is one of my favorite Patreon episodes and I hope you like it too. It’s about animals that can see ultraviolet light.

I was going to make this a frog news episode, but I started writing about a tiny frog from

Brazil called the pumpkin toadlet and the episode veered off in a very interesting direction. But let’s start with that frog.

It’s called the pumpkin toadlet because it’s an orangey-yellow color that is just about the same color as pureed pumpkin. It’s poisonous and lives in the forests of Brazil. During mating season, the pumpkin toadlet comes out during the day, walking around making little buzzing noises. Researchers assumed those were mating calls until they started studying how the pumpkin toadlet and its relations process sounds. It turns out that the pumpkin toadlet probably can’t even hear its own buzzing noise. But they did discover that the pumpkin toadlet fluoresces brightly under UV light.

We’ve talked about this phenomenon before, back in the Patreon episode about animals that glow. Quite a lot of frogs turn out to fluoresce in ultraviolet light, which is a component of daylight. That explains why the pumpkin toadlet comes out during the day in mating season. It wants to be seen by potential mates. It’s actually the frog’s bones that fluoresce, but since it has very thin skin without dark pigment cells, the ultraviolet light can light up the bones.

I wanted to make sure I gave everyone the correct information about ultraviolet light, so I started researching it…and that led me down this rabbit hole. What animals can see in ultraviolet light? Can any humans see ultraviolet light? What does it look like?

Light is made up of waves of varying lengths. The retina at the back of your eyeball contains two types of cells, rods and cones, which are named for their shapes. Rods are for low-light vision and cones are for detail and color vision.

Humans have more cones than rods because we’re diurnal animals, meaning we’re most active during the day. Animals that are mostly nocturnal have more rods than cones, which help them see in low light although they don’t see color as well or sometimes at all as a result.

Most humans can see any color that’s a mixture of red, green, and blue, since we have three types of cone cells that react to wavelengths roughly equivalent to those three colors. Some people have what’s called red-green color blindness, which means either the person doesn’t have cones that sense the color red or cones that sense the color green. Various shades of green and red look alike for these people. Red-green color blindness is much more common in men than in women, with as many as 8% of men having the condition. A lot of times they don’t even know it. When I did my student teaching in a first grade class, one day I prepared a math lesson for the students that involved them sorting a little cup of candy into colors, and after they did the math problems associated with the different colors, they got to eat the candy. One little boy kept sorting certain colors of Skittles into the same column, and when I asked him, he didn’t realize they were different colors. They looked the same to him. So that day I learned to be careful about what kind of candy I used for sorting lessons, and he learned that he had red-green color blindness. My own dad was color blind too. It’s pretty common. Occasionally a person is born without the ability to see colors at all, but that’s extremely rare.

The visible light spectrum, also sometimes called the color spectrum, runs from violet to red. Just below violet is the wavelength referred to as ultraviolet. Many insects and birds can see ultraviolet, but typically an animal that can see ultraviolet can’t see infrared, which is the wavelength of light just past red. Birds that can see ultraviolet can usually see red, but not infrared.

In the original Patreon episode, this is where I said that humans can see ultraviolet light a little, but I was actually wrong. I thought blacklights worked by allowing us to see ultraviolet light, but that’s not the case. Blacklights are lamps that emit mostly ultraviolet light, but we only see a dark purple or blue that the blacklight’s filter allows through. While very few humans can see anything but the purple or blue, insects can see ultraviolet light and are attracted to it. That’s why bug zappers include blacklights. People also like blacklights because the ultraviolet light makes some things glow, which is fun to play with. It can also be useful in surprising ways. A lot of countries print paper money and other important documents with ink patterns that only show up under ultraviolet light. It’s easy to tell if the money or document is a fake if those hidden patterns don’t glow under a blacklight. Some diseases cause the sick person’s urine to glow specific colors under ultraviolet light, which helps a doctor determine what’s wrong with the person so they can be treated. If you have access to a blacklight, remember that even though you can’t see most of the light it emits, it can still hurt your eyes, so don’t stare into it.

Sometimes a person’s eye is diseased or damaged so they have to have the lens replaced with an artificial lens. Very rarely when that happens, the person wakes up after surgery and discovers they’re seeing ultraviolet way more than the rest of us. They report that the color is a pale purplish shade. This sounds cool, except that they have to wear special glasses that block ultraviolet light when they’re outside, since ultraviolet light can damage the eyes. It’s also the spectrum of light that causes sunburns. That’s what the UV means in products that say they block UV light; UV just means ultraviolet.

Many birds have a special cone cell that reacts specially to ultraviolet wavelengths. Urine reflects ultraviolet light, which allows predatory birds to track their prey by following urine trails. Some rodents and marsupials also have this cone cell. Researchers think having four types of cone cells, the three humans have plus the ultraviolet one, used to be the default in all animals, but some have evolved to not have the ultraviolet cone cell since they don’t need it. Some animals only have two types of cone cells, like mice, who can’t see as many colors as humans.

Researchers are just learning that many mammals are able to see ultraviolet much more than the typical human can. Reindeer, for instance, and some common animals like dogs, cats, and ferrets. Since power lines give off ultraviolet light, sometimes in bursts called coronal discharges, researchers now realize animals are affected by the light even though humans can’t see it. Reindeer have always avoided power lines, and now we know why. To them, the coronal discharges are a blaze of bright color that probably hurts their eyes, especially when it reflects off snow. Conservationists are calling for better shielding on power lines to cut down on the light they give out.

Some humans are born with ultraviolet-sensing cone cells, a condition called tetrachromacy. Since the lens of the human eye naturally filters out most ultraviolet light, people can have this extra cone cell and not even know it. They just tend to be better at differentiating colors than people without it. Some studies suggest that as many as 50% of women and 8% of men may be tetrachromatic—and that tetrachromatic women are also carriers of the trait of red-green color blindness. Since my dad was colorblind, that means I carry that trait from the genetic material I inherited from him, but I see colors really well…so maybe I have those extra cone cells! That’s exciting! Maybe you have it too!

But before we all get too excited, think about the mantis shrimp. Instead of four types of cone cells, it has up to 16 types.

Ultraviolet lightwaves are short. Shorter than that are X-rays, and shorter than those are gamma rays, which are ridiculously teeny. If your eyes could see X-rays, it basically just means you’d see a lot of skeletons walking around and it would feel bright all the time even if you closed your eyes, since X-rays penetrate less dense material like skin. If you could see gamma rays, all it would mean is that you could see stuff that was radioactive. Useful, yes, but not everyday useful.

Infrared is a different case, since infrared wavelengths are extremely long. Some animals can see infrared, but mostly they actually sense heat signatures given off by other animals. Night vision goggles work like this, basically allowing whoever wears them to see in infrared. Wavelengths longer than infrared are microwaves and radio waves, which nothing can see because it would pretty much just overwhelm the vision and you could see nothing but light, much of it the afterglow of the Big Bang, when the universe came into being.

A few years ago, a team of scientists working with an infrared laser started reporting occasionally seeing flashes of light where there shouldn’t be visible light. They were scientists, so of course they investigated with a scientific study of the infrared laser on human vision. This was a powerful laser that only emitted infrared light, and emitted it in quick pulses that released a set number of photons at a time. A photon is one particle of light, something along the lines of an atom. I’m not a physicist and don’t really understand it. The study revealed that sometimes, when the laser’s pulses were extremely close together, two photons would be absorbed by a single photopigment in the eye, which was enough to activate the pigment and allow the person to see a flash of light. But because the eye combined the photons, the eye reacted as though the wavelength of the light was half its length, which made it look green.

By the way, rod cells, the ones that help us see in low light, take a few minutes to achieve full sensitivity. That’s why it takes a few minutes for your eyes to adjust after you turn the light out at night.

It’s mind-blowing to think that light is an actual physical thing that actually physically goes into your eyeballs to let you see. There’s more to it than that, of course—nerves and the brain have a lot to do with how we are able to make sense of visual images. If something goes wrong with the eyeball, the nerves that connect it to the brain, or the part of the brain that deals with vision, it can lead to blindness of one kind or another. But at the very basic level, when you see, for instance, a hedgehog, it’s because light photons bounced off that hedgehog and into your eyeball. And that also means that when you look up at the night sky and see stars, you’re seeing the actual physical lightwaves given off by stars millions of light years away that physically go into your eyeball and bounce off the cone and rod cells, activating them and allowing your brain to form an image. That’s amazing, no matter if you can see ultraviolet or if you get the colors of candy mixed up because they look alike to you.

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.

Episode 368: The Bison

Thanks to Jason for suggesting this week’s topic, the bison!

Further reading:

New research documents domestic cattle genetics in modern bison herds

Higgs Bison: Mysterious Hybrid of Bison and Cattle Hidden in Ice Age Cave Art

A cave painting of steppe bison and other animals:

An American bison [photo by Kim Acker, taken from this site]:

Some European bison [photo by Pryndak Vasyl, taken from this site]:

The bison sound in this episode came from this site.

Show transcript:

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

This week we’re going to learn about the bison, a suggestion from Jason. There are two species of bison alive today, the American bison and the European bison. Both are sometimes called buffalo while the European bison is sometimes called the wisent. I’m mostly going to call it the wisent too in this episode so I only have to say the word bison 5,000 times instead of 10,000.

Bison are herd animals that can congregate in huge numbers, but these big herds are made up of numerous smaller groups. The smaller groups are made up of a lead female, called a cow, who is usually older, other cows, and all their offspring, called calves. Males, called bulls, live in small bachelor groups. The American bison mostly eats grass while the European bison eats a wider selection of plants in addition to grass.

The bison is a big animal with horns, a shaggy dark brown coat, and a humped shoulder. The American bison’s shoulder is especially humped, which allows for the attachment of strong neck muscles. This allows the animal to clear snow from the ground by swinging its head side to side. The European bison’s hump isn’t as pronounced and it carries its head higher. The bison looks slow and clumsy, but it can actually run up to 35 mph, or 55 km/hour, can swim well, and can jump obstacles that are 5 feet tall, or 1.5 meters.

The American bison can stand over six and a half feet high at the shoulder, or 2 meters, while the European bison stands almost 7 feet tall at the shoulder, or 2.1 meters. This is massively huge! Bison are definitely ice age megafauna that once lived alongside mammoths and woolly rhinos, so we’re lucky they’re still around. Both species almost went extinct in recent times and were only saved by a coordinated effort by early conservationists.

The American bison in particular has a sad story. Before European colonizers arrived, bison were widespread throughout North America. Bison live in herds that migrate sometimes long distances to find food, and many of the North American tribes were also migratory to follow the herds, because the bison was an important part of their diet and they also used its hide and other body parts to make items they needed. The colonizers knew that, and they knew that by killing off the bison, the people who depended on bison to live would starve to death. Since bison were also considered sacred, the emotional and societal impact of colonizers killing the animals was also considerable.

In the 19th century, colonizers killed an estimated 50 million bison. A lot of them weren’t even used for anything. People would shoot as many bison as possible from trains and just leave the bodies to rot, and this practice was actually encouraged by the railroads, who advertised these “hunting” trips. The United States government also encouraged the mass killing of bison and even had soldiers go out to kill as many bison as possible. Bison that escaped the coordinated slaughter often caught diseases spread by domestic cattle, and the increased plowing and fencing of prairie land reduced the food available to bison. By 1900, the number of American bison in the world was probably only about 300.

As early as the 1860s people started to sound the alarm about the bison’s impending extinction. Some ranchers kept bison, partly as meat animals and partly to just help stop them from all dying out. The Yellowstone National Park had been established in 1872, and 25 bison survived there, although many others were poached by hunters. Members of various Plains tribes, who had been forced onto reservations by the United States government so the government could give their land to colonizers, collected as many bison as they could to keep them safe.

These days the American bison is out of immediate danger, although its numbers are still very low. Because there were so few bison when conservation efforts started, the genetic diversity is also low. Bison will also hybridize with domestic cattle and the resulting female calves are fertile, so the main goal of modern conservationists is to genetically test herds to determine which bison have a larger percentage of cattle genes, and mainly only breed the ones that have the least. A 2022 study determined that there is no population of American bison alive today that doesn’t have at least a small percentage of cattle genes. Cattle are domesticated animals, and it’s never a good thing when a wild animal ends up with the DNA of a domestic counterpart. Bison need their wildness in order to survive and stay safe.

There are two living subspecies of American bison, the wood bison and the plains bison. I’m happy to report that the scientific name of the plains bison is Bison bison bison. The wood bison mainly lives in Canada, where it’s classified as threatened.

As for the European bison, or wisent, it was once common throughout much of Europe and Asia. As the human population increased after the ice age, the wisent’s numbers decreased until it was mostly restricted to a few areas of Russia, Transylvania, Poland, and Lithuania. Even as early as the 16th century, people were aware it was endangered. Local rulers declared it a protected animal in most of its range.

During World War I, German troops occupying Poland killed hundreds of wisents, and as the troops retreated at the end of the war, they shot as many of the bison as they could find and left them to rot. Only nine individuals remained alive and by 1921 they had died too. By 1927, the very last wisent in the wild was killed by a poacher.

But 12 animals remained, kept in various zoos. In 1923 a preservation society was set up, modeled after the one in the United States that had helped save the American bison from extinction. Poland in particular worked hard to increase the wisent’s numbers and re-introduce it to its forest home, although its efforts were interrupted by World War II. These days the wisent is out of danger of extinction, although like the American bison its numbers are still relatively low.

American and European bison are related and can crossbreed, but they’re not as closely related genetically as was once thought. Genetic studies are ongoing, but it appears that the wisent is most closely related to domestic cattle while the American bison is most closely related to the yak.

We recently talked about the steppe bison in episode 357, which is about mammoth meat. The steppe bison is an ancestor of the American bison and lived throughout Europe and Asia across to North America, during the Pleistocene when Asia and North America were connected by the land bridge Beringia. It only went extinct around 3,000 years ago. It had much larger horns than modern bison, with a horn spread of almost seven feet across, or over 2 meters.

About 17,000 years ago, in a cave in what is now France, an ancient artist picked up a stick of charcoal and made a drawing of a bison alongside many other bison drawings made by many artists over the years. According to a study published in 2016, there are two different types of bison depicted in the cave. One type is the steppe bison, but the other is distinctly different. After a genetics study of bison in Europe, researchers made a surprising discovery. The second type of bison depicted in the cave is actually a hybrid animal. Hybrids come about when two species of closely related animals interbreed. The more closely related the species are, the more likely they are to interbreed where their territories overlap, and the more likely that the offspring will be fertile. This is exactly what happened toward the end of the Pleistocene, when climate change made it harder for the steppe bison to survive. Instead, a hybrid of steppe bison and the aurochs, the wild ancestor of the domestic cow, not only became common throughout much of Europe, eventually the hybrid species was so numerous that it became a distinct species of its own.

This hybrid bison had small horns and a smaller hump than the steppe bison, although it was still a really big animal. Eventually it gave rise to the modern European bison while the steppe bison gave rise to the antique bison, which itself is the direct ancestor of the American bison. So many bison!

This is what a bison sounds like, specifically an American bison recorded in Yellowstone National Park:

[bison sound]

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 367: The Marozi

Thanks to Pranav for suggesting this mystery big cat this week, the marozi!

Further reading:

From Black Lions to Living Sabre-Tooths: My Top Ten Mystery Cats

Spotted Lions

A young lioness who still has some of her cub spots:

Subadult lions who still have a lot of cub spots:

The skin of an animal supposedly killed in 1931 and said to be a marozi:

Two photos of a “leopon,” a lion-leopard hybrid bred in captivity in a Japanese zoo:

Show transcript:

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

This week we’re going to learn about a mystery animal suggested by Pranav. It’s the marozi, a big cat from the mountains of Kenya.

Kenya is in east Africa, and humans have lived in what is now Kenya since humans existed. Because of this, usually when we talk about Kenya or east Africa, we’re talking about hominins, but today we’re talking about big cats.

Kenya is home to a lot of animals you think of when someone mentions the animals of Africa, like elephants and giraffes, and it’s also home to three big cats: lions, leopards, and cheetahs. The lion is generally a tawny brown color although different individuals and populations can be various shades of brown or gray. A lion cub is born with dark spots, and as it grows the spots fade. Sometimes a young adult lion will still have some spots, especially on its legs and belly, but in general an adult lion has no spots at all. In comparison, both the leopard and the cheetah are famous for their spots.

The lion prefers to live in savannas and open woodlands. These days it’s only found in a few parts of India, along with various places in sub-Saharan Africa. This just means south of the Sahara desert. In the past, though, the lion had a much larger range. It lived throughout most of Africa, the Middle East, southern Asia, and even southern Europe. Overhunting drove it to extinction in many parts of its historic range, which is called extirpation. I’ve used the term before but it specifically means that an animal has been driven to extinction in one area where it once lived, but it isn’t extinct in other areas. Some subspecies of lion have gone extinct, and the lions who remain are vulnerable to habitat loss, poaching, and many other factors. Just because lions are common in zoos doesn’t mean lions in the wild are doing fine.

The same is true of the cheetah, which has an even smaller range than the lion these days but which was once common throughout Africa and the Middle East along with a lot of southern Asia and Europe. We talked about the cheetah in episode 145. It’s actually not closely related to the lion or the leopard, and in fact genetic testing reveals that it’s most closely related to the puma of North America.

The leopard, on the other hand, is a very close relation to the lion. Both belong to the same genus, Panthera, which also includes tigers, jaguars, and snow leopards, but the lion and leopard are the closest cousins. While it’s also vulnerable to habitat loss, poaching, and other factors, it’s more widespread than the lion and cheetah. It lives throughout much of sub-Saharan Africa, Asia–especially India–and even parts of eastern Russia, and in the past it was even more widespread. It prefers forests where its spots help it blend in with dappled sun and shade.

So, the lion, the leopard, and the cheetah all live in Kenya, but there’s another big cat that’s supposed to live there too. It’s called the marozi, also sometimes called the spotted lion.

Stories of lions that have spots like a leopard go back for centuries among the local people. The spotted lion is supposed to be small and the male either has no mane or only a small one. It’s supposed to live in the mountains and is solitary instead of living in family groups like ordinary lions. In fact, “marozi” supposedly means “solitary lion” in the local language. Instead of living in open grasslands, it lives in thick forest where a spotted coat and smaller body size would be useful, allowing it to maneuver through the trees more easily while not being seen.

It wasn’t until the colonial era in the late 19th and early 20th centuries that Europeans became aware of the marozi. The first known sighting of a spotted lion by a European occurred in 1903, when a British soldier reported seeing more than one in the mountains of Kenya. He said the lions were darker in color than an ordinary lion, with leopard-like rosette markings. In 1924, a game warden reported killing a spotted lioness and her cubs, with the lioness having just as many spots as the babies.

In 1931 a farmer shot two small spotted lions in the mountains. He said they were fully grown despite their small size, but they had even more spots than lion cubs do. One was a male and he had a sparse, short mane. The farmer kept the male’s skin, which eventually made its way to the Natural History Museum in London, possibly with the lion’s skull too, although it’s not clear if the skull actually belongs to the same animal. As far as I could find out, no one has tried to test the skin and skull genetically.

Other people, including hunters and game wardens, reported seeing spotted lions in high elevations where ordinary lions didn’t live, with stories continuing through at least the 1960s. Similar stories of a spotted lion have been collected from mountains in other parts of east and central Africa, including Ethiopia, Rwanda, Uganda, and Cameroon, where it has different local names. But so far we don’t have any photographs or a specimen.

There are a few hypotheses about what the marozi might be. One suggestion is that it’s actually a hybrid of a leopard and a lion. Because leopards and lions are so closely related, they can interbreed and produce offspring, although as far as we know this has only happened in captivity. In the wild, lions are actually aggressive towards leopards. A lion will steal a leopard’s food and will sometimes even kill leopards, and as a result leopards try to avoid lions. Since leopards prefer thick forest and lions prefer open forest or grasslands, they don’t cross paths all that often anyway.

In the late 1950s into the early 1960s, a zoo in Japan kept a male leopard and a female lion in the same enclosure to see if they would mate. They did, and eventually they had two litters together. The cubs were larger and heavier than leopards but not as big as lions, and while they generally looked like lions they had leopard spots. The males had small manes.

This sounds a lot like reports of the marozi, but again, in the wild lions and leopards mostly avoid each other. The only time a lion and a leopard would consider each other potential mates instead of potential trouble is when they’re put together artificially as in the Japanese zoo. Even if an occasional leopard and lion do sometimes breed in the wild, it wouldn’t happen often enough to cause all the sightings documented about the marozi. Besides, the marozi is only reported from the mountains, where lions don’t live.

Another hypothesis is that there’s a population of ordinary lions that have moved into the mountains to escape factors like habitat loss, poaching, and a decline in prey animals, and that people occasionally see a young adult lion that hasn’t completely lost its cub spots. This isn’t too likely either since stories of the marozi go back to long before these modern pressures on lion populations.

There might very well be an unknown, very rare species or subspecies of lion that has always lived in the mountains in parts of east and central Africa, and that it does actually have spots as an adult. If this is the case, hopefully it’s safe in its mountain habitat from the pressures faced by ordinary lions. Let’s hope also that it comes to the attention of scientists soon so it can be studied and protected.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. 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 366: The Muntjac AKA Deer with Fangs

Thanks to Chuck for suggesting this week’s topic, a weird little deer called the muntjac!

Further reading:

Dam Project Reveals Secret Sanctuary of Vanishing Deer

Wildlife camera trap surveys provide new insights into the occurrence of two threatened Annamite endemics in Viet Nam and Laos

Getting ahead (or two?) with Vietnam’s Viking Deer – the Long-Running Saga of a Slow-Running Mystery Beast

A giant muntjac [photo by Mark Kostich, taken from article linked above]:

A Reeve’s muntjac [photo by Don Southerland, taken from this site]:

Show transcript:

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

This week we have a suggestion from Chuck, who wanted to learn about a small hoofed animal that I don’t think we’ve ever covered before, the muntjac. It’s a deer, but it’s a very weird deer.

In fact, it’s not just one deer, it’s at least 12 different species that are native to parts of south and southeast Asia, although it used to have a much broader range. Muntjac fossils have been found throughout Europe in particular. It prefers thick forests with lots of water around. Most species live in tropical or subtropical areas, although it can tolerate colder temperatures. It eats leaves, grass, fruit, seeds, and other plant parts, and it will also sometimes eat bird eggs and small animals when it finds them. It will even sometimes eat carrion.

The typical muntjac is small, barely larger than a fox. The largest species, the giant muntjac, stands a little over two and a half feet tall at the shoulder, or 80 cm, while there are several species of muntjac that don’t grow taller than 15 inches high, or 40 cm. It’s brown or reddish-brown, sometimes with darker or lighter markings depending on species. The muntjac appears hump-backed in shape like a rabbit, since instead of having a mostly level back, its back slopes upward from the shoulders to the rump. Its tail is very short and males grow short antlers that either have no branches or only one branch. Males also have a single pair of sharp, curved fangs that grow down from the upper jaw, more properly called tusks.

The muntjac is usually a solitary animal, with each individual defending a small territory. Both males and females have a large gland near the eye that secretes an oily substance with a strong smell. It also has another pair of scent glands on the forehead. The muntjac rubs its face on the ground to mark the edges of its territory with scent. It can even flare its scent glands open to communicate with other muntjacs by smell more effectively.

Unlike many deer species, the muntjac doesn’t have a particular mating season. Females, called does, can come into season any time of the year, so males are always ready to fight with other males for a doe’s attention. The male loses and regrows his antlers yearly, but mainly he only uses them to push an opponent over. He does the real fighting with his fangs.

There are other types of hoofed animals with fangs. We talked about the musk deer and the chevrotain in episode 116, but even though the chevrotain in particular looks a lot like the muntjac, it’s not closely related to it at all. Neither is the musk deer. In fact, neither the musk deer nor the chevrotain are actually deer, and they’re not even closely related to each other.

The southern red muntjac is one of the smallest species of muntjac known and is fairly common throughout much of southeast Asia, although we don’t know much about it. One thing we do know is that it has the smallest number of chromosomes of any mammal ever studied. Males have 7 diploid chromosomes and females only have 6. In comparison, the common Reeve’s muntjac has 46 diploid chromosomes. Scientists have no idea why there’s so much difference in chromosome count between species, but it works for the muntjac.

Many species of muntjac are common and are doing just fine, but others are endangered due to habitat loss, hunting, and the other usual factors we talk about a lot. But the muntjac is small, solitary, and very shy, so there are also species that are probably still waiting to be discovered.

The giant muntjac, also called the large-antlered muntjac, was only discovered in 1994 from a skull found in Vietnam. Scientists were eager to learn more about the animal, especially whether it was still alive or had gone extinct. They talked to hunters and other local people in Vietnam and Laos, and set up camera traps, and went on expeditions searching for it. The hunters said it was still around but the scientists just couldn’t find any. It wasn’t until 1997 that a camera trap took a few pictures of one near a newly constructed dam, which gave everyone hope that this animal could be saved from possible extinction.

Scientists had been searching for the giant muntjac for so long, and had only finally gotten a photograph after 13 years of trying, that they figured it would be an even longer time before they learned more about it. But then, suddenly, only four months after the first pictures of the giant muntjac were captured, a team of conservationists working to relocate animals from the flood area of the new dam ended up capturing 38 of the deer.

When a new dam is constructed across a river or other waterway, it doesn’t flood right away. It takes a long time for the water to back up behind the dam and turn into a lake or large pond, sometimes several years depending on the size of the dam and the waterway. There’s time to relocate animals to higher ground so they’ll be safe, and that’s exactly what Ulrike Streicher and her team were doing in 2007. Not only that, they made sure to transport the animals to a protected area where they’d be safer from hunters. Before they released the giant muntjacs, they had the opportunity to study them and fit some of them with radio collars so the scientists could track where they went. It turned out that the muntjacs settled into their new home just fine, so although the giant muntjac is still classified as critically endangered, at least we know that one small population is doing well.

Another muntjac search involves a camera trap in Vietnam and Laos too, but it’s still an ongoing mystery. The story actually starts back in 1929 when a dead muntjac was sent to the Field Museum in Chicago. The scientists at the museum couldn’t identify it as any known species of muntjac, so they described it in 1932 as Muntiacus rooseveltorum, also called Roosevelt’s muntjac. Modern genetic testing of the specimen determined that it’s a subspecies of Fea’s muntjac that lives in a small area of southern Myanmar and Thailand. Fea’s muntjac itself is so rare and so little known that we don’t even know if it’s extinct or not. As for Roosevelt’s muntjac, no one had seen it since the 1929 specimen was killed and it was presumed extinct.

Then, starting in 2014, a team of scientists conducted surveys in parts of the Annamites, a mountain range along the Vietnam/Laos border. Over the next five or six years, camera traps recorded every animal that passed by them in various remote locations. In addition to lots of animals the scientists expected to see, they found three animals that were either extremely rare or thought extinct. One of these was the Annamite striped rabbit we talked about in episode 254, but the other two were muntjacs.

One of the muntjacs captured on camera was identified as Roosevelt’s muntjac while the other was identified as the Annamite muntjac, a species that was only identified in 1997. The problem is that we only have pictures of the animals, and only a single specimen of Roosevelt’s muntjac to compare the pictures to. Scientists disagree as to whether Roosevelt’s muntjac is for sure still alive and well in the Annamite mountains, or whether the pictures are of a totally different species of muntjac. At least the pictures were taken in a nature reserve, so we know the muntjacs should be safe.

Muntjacs are such strange, attractive animals that rich people used to keep them as pets to show off. Sometimes they would escape into the wild, or were even released on purpose, and that’s why Japan, England, Wales, Belgium, the Netherlands, and Ireland all have invasive populations of Reeve’s muntjac. Reeve’s muntjac is common in southeastern China and Taiwan and only grows a little over a foot high at the shoulder, or maybe half a meter. The male has stubby little antlers and long tusks, so that his tusks are almost as long as his antlers. Cute as the animals are, they’re also bad for the local ecosystems, since they reproduce quickly and eat food that native animals need.

Rumors have circulated for a few decades now of another possible mystery muntjac, usually referred to as the quang khem. Supposedly it’s a large muntjac with unbranched antlers that lives in remote areas of Vietnam. So far it hasn’t been discovered, if it exists at all, but there’s definitely a chance that it’s yet another muntjac that’s just waiting to be spotted by scientists or their camera traps.

The muntjac is sometimes called the barking deer because of its alarm call. This is what a muntjac sounds like:

[muntjac barking sound]

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