Category Archives: Africa

Episode 354: Sheep and Sivatherium

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Thanks to Hannah, who suggested sheep as this week’s topic! We’ll also learn about a few other hoofed animals, including the weird giraffe relative, sivatherium.

Further reading:

The American Jacob Sheep Breeders’ Association

What happened with that Sumerian ‘sivathere’ figurine after Colbert’s paper of 1936? Well, a lot.

A Jacob sheep ewe with four horns (pic from JSBA site linked above):

The male four-horned antelope [photo by K. Sharma at this site]:

A modern reconstruction of sivatherium that looks a lot like a giraffe [By Hiuppo – Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=2872962]:

The rein ring in question (on the left) that might be a siveratherium but might just be a deer:

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 Hannah a long time ago. Hannah suggested we talk about sheep, and I can’t even tell you how many times I almost did this episode but decided to push it back just a little longer. Finally, though, we have the sheep episode we’ve all been waiting for! We’re also going to learn about a strange animal called sivatherium and a mystery surrounding when it went extinct.

The sheep has cloven hooves and is a ruminant related to goats and cattle. It mostly eats grass, and it chews its cud to further break down the plants it eats. It’s one of the oldest domesticated animals in the world, with some experts estimating that it was first domesticated over 13,000 years ago. Mammoths still roamed the earth then. Sheep are especially useful to humans because not only can you eat them, they produce wool.

Wool has incredible insulating properties, as you’ll know if you’ve ever worn a wool sweater in the snow. Even if it gets wet, you stay nice and warm. Even better, you don’t have to kill the sheep to get the wool. The sheep just gets a haircut every year to cut its wool short. Wild sheep don’t grow a lot of wool, though. They mostly have hair like goats. Humans didn’t start selecting for domestic sheep that produced wool until around 8,000 years ago.

Like other animals that were domesticated a very long time ago, including dogs and horses, we’re not sure what the direct ancestor of the domestic sheep is. It seems to be most closely related to the mouflon, which is native to parts of the middle east. The mouflon is reddish-brown with darker and lighter markings and it looks a lot like a goat. Other species of wild sheep live in various parts of the world but aren’t as closely related to the domestic sheep. The bighorn and Dall sheep of western North America are closely related to the snow sheep of eastern Asia and Siberia. The ancestors of all three species spread from eastern Asia into North America during the Pleistocene when sea levels were low and Asia and North America were connected by the land bridge Beringia.

The male sheep is called a ram and grows horns that curl in a spiral pattern, while the female sheep is called a ewe. Some ewes have small horns, some don’t. This is the case for both wild and domestic sheep. Sheep use their horns as defensive weapons, butting potential predators who get too close, and they also butt each other. Rams in particular fight each other to establish dominance, although ewes do too.

But some breeds of domestic sheep are what is called polycerate, which means multi-horned. That means a sheep may have more than two horns, typically up to six. Many years ago I kept a few Jacob sheep, which are a polycerate breed, and in a Patreon episode from 2018 I went into really too much detail about this particular breed of sheep. I will cut that short here.

The Jacob is a hardy, small sheep with tough hooves, and it’s white with black spots. Ideally, a Jacob sheep will have four or six well-balanced horns. In a six-horned sheep, the upper pair branch upward, the middle pair curl like an ordinary ram’s horns, and the lower pair branch downwards. Sometimes a sheep will have three or five horns, or will start out with four horns but as they grow, two will merge so it looks like they have a single horn on one side. Sometimes a ram’s horns will grow so large that the blood supply is choked off for the lower pair, which will die and stop growing. Breeding a pair of six-horned Jacob sheep doesn’t guarantee that the babies will have more than two horns, though. It’s still a recessive trait.

Sheep, goats, cattle, and some antelopes are all bovids. Polyceratism appears to be a bovid trait. It’s caused by a mutation where the horn core divides during the animal’s development.

Occasionally, a sheep of non-polycerate breed, or a goat, or even a cow, is born with multiple horns. The blue wildebeest is also occasionally born with multiple horns. Sometimes an animal grows a lot of horns, like eight, but usually it’s three, four, five, or six.

Another animal with more than two horns is the four-horned antelope that lives in India and Nepal. Its horns are quite small, just a pair of tiny points on the forehead with a pair of longer points behind them. The antelope itself is also small, not much more than two feet tall at the shoulder, or 60 cm. Its coat is reddish or yellowish-brown with white underparts, and a black stripe down the front of the legs. The longer horns grow up to about five inches long, or 12 cm, but the front horns are no longer than two inches, or five cm.

The four-horned antelope is shy and solitary, and lives in open forests near water. Since it’s so small, it frequently hides in tall grasses. Sometimes a four-horned antelope’s front two horns are just bumps covered with fur, which makes them look like ossicones although they’re still actually horns.

That brings us to the other group of animals with multiple horns, although they’re not actually horns. I mentioned ossicones in the tallest animals episode, about giraffes. They’re made of ossified cartilage instead of bone, and are covered in skin and fur instead of a keratin sheath. Antlers are actually very similar to ossicones in many ways. A deer’s antlers grow from a base that is similar to an ossicone, and as they grow, the antlers are covered with tissue called velvet that later dries and is scraped off by the deer to show off the bony antlers. Unlike horns, which are always unbranched, the ossicones of some extinct animals can look like antlers.

We talked about sivatherium in episode 256, about mammoths. It was an ancestor of modern giraffes that lived in Africa and India around a million years ago. It stood around 7 feet tall at the shoulder, or just over two meters, but had a relatively long neck that made it almost 10 feet tall in total, or about three meters. It had two pairs of ossicones, one pair over its eyes and another between its ears. Like the four-horned antelope, the front pair were smaller than the rear pair, but the rear pair was broad and had a single branch.

Sivatherium was once believed to be closely related to elephants, and reconstructions of it often made it look like a moose with a short trunk. But modern understanding of its anatomy suggests it looked like a heavily built giraffe with shorter legs and neck, sort of like the giraffe’s closest living relative, the okapi.

One interesting thing about Sivatherium is how recently it may have been alive. Some researchers think it may have been around only 8,000 years ago. There’s rock art in India and the Sahara that does seem to show a long-necked animal with horns that isn’t a giraffe. The art has been dated to around 15,000 years ago. But the big controversy is a figurine discovered in 1928.

That’s when a copper rein ring was found in Iraq and dated to about 2800 BCE. A rein ring was part of the harness to a four-wheeled chariot, with two holes to thread the reins through to keep them from tangling. Above the rings was a little decorative figure of an animal. This particular rein ring’s figure shows an animal with short horns above the eyes and branching horn-like structures farther back, between the ears. When it was originally discovered, scientists thought the figure represented a type of fallow deer found in the area, with the ends of the antlers broken off. But one researcher, Edwin Colbert, pointed out that no deer known has four antlers and the figure clearly has two little bumps over its eyes that are separate from the branched antler or horn-like structures farther back. In 1936 he published his conclusion that the animal wasn’t a deer at all but sivatherium, and a lot of scientists agreed.

That would mean sivatherium might have been alive less than 5,000 years ago. Part of the issue is that sivatherium’s branched ossicones weren’t very big in comparison to its head, while the fallow deer’s antlers are proportionally quite large. The figurine has structures that match sivatherium’s ossicones more than a deer’s antlers. But in 1977, two little pieces of copper were found in a storage box where they’d been since the original discovery of the rein ring. The pieces fit exactly onto the ends of the figure’s horns, showing that the horns are much bigger than originally thought.

That doesn’t explain everything, though. The figure still has those extra little horns over its eyes, and while the branched horns look like deer antlers, they still don’t look like fallow deer antlers. Some researchers point out that sivatherium had a lot of variation in the size and shape of its ossicones, too.

Ultimately there’s not enough evidence either way of whether the figurine depicts a deer or sivatherium. If sivatherium did live as recently as a few thousand years ago, hopefully remains of it will be found soon. Until we know for sure, you can still be glad that the giraffe is alive, because it’s just as amazing as its extinct relation.

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 348: Australopithecus and Gigantopithecus

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Thanks to Anbo for suggesting Australopithecus! We’ll also learn about Gigantopithecus and Bigfoot!

Further reading:

Ancient human relative, Australopithecus sediba, ‘walked like a human, but climbed like an ape’

Human shoulders and elbows first evolved as brakes for climbing apes

You Won’t Believe What Porcupines Eat

Past tropical forest changes drove megafauna and hominin extinctions

An Australopithecus skeleton [photo by Emőke Dénes – kindly granted by the author, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=78612761]:

Show transcript:

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

It’s officially monster month, also known as October, so let’s jump right in with a topic suggested by Anbo! Anbo wanted to learn about Australopithecus, and while we’re at it we’re going to talk about Gigantopithecus and Bigfoot. On our spookiness rating scale of one to five bats, where one bat means it’s not a very spooky episode and five bats means it’s really spooky, this one is going to fall at about two bats, and only because we talk a little bit about the Yeti and Bigfoot at the end.

In 1924 in South Africa, the partial skull of a young primate was discovered. Primates include monkeys and apes along with humans, our very own family tree. This particular fossil was over a million years old and had features that suggested it was an early human ancestor, or otherwise very closely related to humans.

The fossil was named Australopithecus, which means “southern ape.” Since 1924 we’ve discovered more remains, enough that currently, seven species of Australopithecus are recognized. The oldest dates to a bit over 4 million years old and was discovered in eastern Africa.

Australopithecus was probably pretty short compared to most modern humans, although they were probably about the size of modern chimpanzees. A big male might have stood about 4 ½ feet tall, or 1.5 meters. They were bipedal, meaning they would have stood and walked upright all the time. That’s the biggest hint that they were closely related to humans. Other great apes can walk upright if they want, but only humans and our closest ancestors are fully bipedal.

In 2008 a palaeoanthropologist named Lee Rogers Berger took his nine-year-old son Matthew to Malapa Cave in South Africa. Dr. Berger was leading an excavation of the cave and Matthew wanted to see it. While he was there, Matthew noticed something that even his father had overlooked. It turned out to be a collarbone belonging to an Australopithecus boy who lived almost 2 million years ago. Later, Dr Berger’s team uncovered more of the skeleton and determined that the remains belonged to a new species of Australopithecus, which they named Australopithecus sediba. More remains of this species were discovered later, including a beautifully preserved lower back. That discovery was important because it allowed scientists to determine that this species of Australopithecus had already evolved the inward curve in the lower back that humans still have, which helps us walk on two legs more easily. That was a surprise, since A. sediba also still shows features that indicate they could still climb trees like a great ape.

It’s possible that Australopithecus, along with other species of early humans, climbed trees at night to stay safe from predators. In the morning, they climbed down to spend the day mostly on the ground. One study published only a few weeks ago as this episode goes live suggests that the flexible shoulders and elbows that humans share with our great ape cousins originally evolved to help apes climb down from trees safely. Monkeys don’t share our flexible shoulder and elbow joints because they’re much lighter weight than a human or ape, and don’t need as much flexibility to keep from falling while climbing down. Apes and hominins like humans can raise our arms straight up over our heads, and we can straighten our arms out completely flat. Australopithecus could do the same. The study suggests that when another human ancestor, Homo erectus, figured out how to use fire, they stopped needing to climb trees so often. They evolved broader shoulders that allowed them to throw spears and other weapons much more accurately.

Australopithecus probably mostly ate fruit and other plant materials like vegetables and nuts, along with small animals that they could catch fairly easily. This is similar to the diet of many great apes today. The big controversy, though, is whether Australopithecus made and used tools. Their hands would have been more like the hands of a bonobo or chimpanzee, which have a lot of dexterity, but not the really high-level dexterity of modern humans and our closest ancestors. Stone tools have been found in the same areas where Australopithecus fossils have been found, but we don’t have any definitive proof that they made or used the tools. There were other early hominins living in the area who might have made the tools instead.

We also don’t really know what Australopithecus looked like. Some scientists think they had a lot of body hair that would have made them look more like apes than early humans, while some scientists think they had already started losing a lot of body hair and would have looked more human-like as a result.

There’s no question these days that Australopithecus was an early human ancestor. We don’t have very many remains, but we do have several skulls and some nearly complete skeletons, which tells us a lot about how our distant ancestor lived. But we know a lot less about a fossil ape that lived as recently as 350,000 years ago, and it’s become confused with modern stories of Bigfoot.

Gigantopithecus first appears in the fossil record about 2 million years ago. It lived in what is now southern China, although it was probably also present in other parts of Asia. It was first discovered in 1935 when an anthropologist identified two teeth as belonging to an unknown species of ape, and since then scientists have found over a thousand teeth and four jawbones, more properly called mandibles.

The problem is that we don’t have any other Gigantopithecus bones. We don’t have a skull or any parts of the body. All we have are a few mandibles and lots and lots of teeth. The reason we have so many teeth is because Gigantopithecus had massive molars, the biggest of any known species of ape, with a protective layer of enamel that was as much as 6 mm thick. Some of the teeth were almost an inch across, or 22 mm. A lot of the remaining bones were probably eaten by porcupines, and in fact the mandibles discovered show evidence of being gnawed on. This sounds bizarre, but porcupines are well-known to eat old bones along with the shed antlers of deer, which supplies them with important nutrients. The teeth were too hard for the porcupines to eat.

We know that Gigantopithecus was a big ape just from the size of its mandible, but without any other bones we can only guess at how big it really was. It was potentially much bigger and taller than even the biggest gorilla, but maybe it had a great big jaw but short legs and it just sat around and ate plants all the time. We just don’t know.

What we do know is that its massive jaw and teeth were adapted for eating fibrous plant material, not meat. The thick enamel would help protect the teeth from grit and dirt, which suggested it ate tubers and roots that would have had a lot of dirt on them, although its diet was probably more varied. Scientists have even discovered traces of seeds from fruits belonging to the fig family stuck in some of the fossilized teeth, and evidence of tooth cavities that would have resulted from eating a lot of fruit long before toothpaste was invented.

Many scientists thought at first that Gigantopithecus was a human ancestor, but one that grew to gigantic size. It was even thought to be a close relation to Australopithecus. Other scientists argued that Gigantopithecus was more closely related to modern great apes like the orangutan. The debate on where Gigantopithecus should be classified in the ape and human family tree happened to overlap with another debate about a giant ape-like creature, the Yeti of Asia and the Bigfoot of North America.

We talked about the Yeti way back in episode 35, our very first monster month episode in 2017. Expeditions by European explorers to summit Mount Everest, which is on the border between China and Nepal, started in 1921. That first expedition found tracks in the snow resembling a bare human foot at an elevation of 20,000 feet, or 6,100 meters. They realized the tracks were probably made by wolves, with the front and rear tracks overlapping, which only looked human-like after the snow melted enough to obscure the paw pads. Expedition leader Charles Howard-Bury wrote in a London Times article that the expedition’s Sherpa guides claimed the tracks were made by a wild hairy man, but he also made it clear that this was just a superstition. But journalists loved the idea of a mysterious wild man living on Mount Everest. One journalist in particular, Henry Newman, interviewed the guides and specifically asked them about the creature. He wrote a sensational account of the wild man, but he mistranslated their term for it as the abominable snowman.

The word Yeti comes from a Sherpa term yeh-teh, meaning “animal of rocky places,” although it may be related to the term meh-teh, which means man-bear. But the peoples who live in and around the Himalayas belong to different cultures and speak a lot of different languages. There are lots of stories about the hairy wild man of the mountains, and lots of different words to describe the creature of those stories. And the idea of the Yeti that has become popular in Europe and North America doesn’t match up with the local stories. Locals describe the Yeti as brown, black, or even reddish in color, not white, and it doesn’t always have human-like characteristics. Sometimes it’s described as bear-like, panther-like, or just a general monster.

The abominable snowman, or Yeti, became popular in newspaper articles after the 1921 Mount Everest expedition, and it continued to be a topic of interest as expeditions kept attempting to summit the mountain. It wasn’t until May 26, 1953 that the first humans reached the tippy-top of Mount Everest, the New Zealand explorer Edmund Hillary and the Nepali Sherpa climber Tenzing Norgay. Many other successful expeditions followed, including some that were mounted specifically to search for the Yeti.

In the meantime, across the planet in North America, a Canadian schoolteacher and government agent named John W. Burns was collecting reports of hairy wild men and giants from the native peoples in British Columbia. He’s the one who coined the term Sasquatch in 1929. In the 1930s, a man in Washington state in the U.S, which is close to British Columbia, Canada, carved some giant feet out of wood and made tracks with them in a national forest to scare people, leading to a whole spate of big human-like tracks being faked in California and other places. But it wasn’t until 1982 that the hoaxes started to be revealed as the perpetrators got old and decided to clear up the mystery.

But in the 1920s and later, the popularity of the abominable snowman in popular media, giant gorillas like King Kong in the movies, the Yeti expeditions in the Himalayas, the mysterious giant footprints on the west coast of North America, and John Burns’s articles about the Sasquatch all combined to make Bigfoot, a catchall term for any giant human-like monster, a modern legend. People who believed that Bigfoot was a real creature started looking for evidence of its existence beyond footprints and reports of sightings. In 1960, a zoologist writing about a photograph of supposed Yeti tracks taken in 1951 suggested that the Yeti might be related to Gigantopithecus.

On the surface this actually makes sense. The Yeti, AKA the abominable snowman, is reported in the Himalayan Mountains of Asia. The mountain range started forming 40 to 50 million years ago when the Indian tectonic plate crashed into the Eurasian plate very slowly, pushing its way under the Eurasian plate and scrunching the land up into massively huge mountains. It’s still moving, by the way, and the Himalayas get about 5 mm taller every year. The eastern section of the Himalayas isn’t that far from where Gigantopithecus remains have been found in China, and we also know that at many times in the earth’s recent past, eastern Asia and western North America were connected by the land bridge Beringia. Humans and many animals crossed Beringia to reach North America, so why not Gigantopithecus or its descendants? That would explain why Bigfoot is so big, since in 1957 one scientist estimated that Gigantopithecus might have stood up to 12 feet tall, or 3.7 meters.

Some people still think Gigantopithecus was a cousin of Australopithecus, that it walked upright but was huge, and that its descendants are still around today, hiding in remote areas and only glimpsed occasionally. But people who believe such an idea are stuck in the past, because in the last 60 years we’ve learned a whole lot more about Gigantopithecus.

These days, more sophisticated study of Gigantopithecus fossils have allowed scientists to classify it as a great ape ancestor, not an early human. Gigantopithecus was probably most closely related to modern orangutans, in fact, and may have shared a lot of traits with orangutans. It probably could walk upright if it wanted to, but it wasn’t fully bipedal the way humans and human ancestors are. One theory prevalent in 2017 when we talked about the Yeti before was that Gigantopithecus mostly ate bamboo and might have gone extinct when the giant panda started competing with its food sources. This theory has already fallen out of favor, though, and we know that Gigantopithecus was eating a much more varied diet than just bamboo.

We also know that Gigantopithecus lived in tropical broadleaf forests common throughout southern Asia at the time. About a million years ago, though, many of these forests became grasslands. Gigantopithecus probably went extinct as a direct result of its forest home vanishing. It just couldn’t find enough food and shelter on open grasslands, and even though it held on for hundreds of thousands of years, by about 350,000 years ago it had gone extinct. Around 100,000 years ago the forests started reclaiming much of these grasslands, but by then it was too late for Gigantopithecus. Meanwhile, the oldest evidence we have of the land bridge Beringia joining Asia and North America was 70,000 years ago.

There is no evidence that any Gigantopithecus descendant survived to populate the Himalayas or migrated into North America. For that matter, there’s no evidence that Bigfoot actually exists. If a live or dead Bigfoot is discovered and studied by scientists, that would definitely change a lot of things, and would be really, really exciting. But even if that happened, I’m pretty sure we’d find that Bigfoot wasn’t related to Gigantopithecus. Whether it would be related to Australopithecus and us humans is another thing, and that would be pretty awesome. But first, we have to find evidence that isn’t just some footprints in the mud or snow.

Some Bigfoot enthusiasts suggest that the reason we haven’t found any Bigfoot remains is the same reason why we don’t have Gigantopithecus bones, because porcupines eat them. But while porcupines do eat old dry bones they find, they don’t eat fresh bones and they don’t eat all the bones they find. For any bone to fossilize is rare, so the more bones that are around, the more likely that one or more of them will end up preserved as fossils. Bones of modern animals are much easier to find, porcupines or no, but we don’t have any Bigfoot bones. We don’t even have any Bigfoot teeth, which porcupines don’t eat.

Porcupines can be blamed for a lot of things, like chewing on people’s cars and houses, but you can’t blame them for eating up all the evidence for Bigfoot.

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 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 345: Spotless Giraffes and Spotted Zebras

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This week let’s learn about some astonishing giraffes and zebras that don’t look like you’d expect!

Further reading:

See the Rare, Spotless Giraffe Born at a Tennessee Zoo

Giraffe Conservation Foundation

Brights Zoo

A tale of two zebras: South African photos used in misleading posts about Kenya’s polka-dot foal

Zebra News: Spotted Tira, Zonkeys and Zorses

Further viewing:

The Mysterious Return of Tira the Spotted Dark Zebra in Masai Mara

Kipekee the spotless giraffe [pic is from the first link posted above]:

The picture posted on Facebook by Giraffe Conservation Foundation on Sept. 10, 2023:

Tira the spotted zebra as a baby in 2019:

Tira the spotted zebra is getting so grown up (or was in 2021)!

A DIFFERENT spotted zebra from South Africa:

Show transcript:

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

I’m back from Dragon Con, where I had a great time as usual! I was careful and wore a mask while I was around other people, but masking works best when everyone wears a mask, which as we all know doesn’t happen very often right now. Luckily I didn’t get covid, but I did come down with an ordinary cold. I’m just about over it now, though, so hopefully I don’t sound too bad.

I live in Tennessee, and before I left for Dragon Con I kept seeing news reports about an unusual baby giraffe born in a Tennessee zoo. You may have heard about the giraffe calf too. As you probably know, giraffes have an elaborate pattern of markings called spots, although they’re not spots like a leopard’s spots. They look a lot like the cracks in a dried-up mudpuddle, where the muddy parts are dark brown or orangey-brown, and the cracks in between are tan or white. It’s sometimes called a web pattern, where the lighter design looks like a web overlaid on a darker coat.

Whatever you call it, all giraffes have these markings. But on July 31, 2023, a calf was born that didn’t have any spots at all. She’s completely brown. Also, very beautiful and cute as a little button.

The calf was born at Brights Zoo, which is near a community called Limestone in Tennessee. I’d never heard of the zoo, so I assumed it was in middle or west Tennessee, and I live in east Tennessee. But when I looked it up, it’s actually quite close to me. I will definitely be visiting as soon as I get a chance! (Its website says Google Maps has its address wrong, by the way, in case you plan to visit it too.) It’s a private zoo dedicated to education and conservation, and among the animals they care for are giraffes.

The calf in question is an endangered reticulated giraffe. Conservationists estimate that fewer than 9,000 reticulated giraffes remain in the wild these days, but it does well in captivity and is a popular animal in zoos. The reticulated giraffe was once common throughout northeast Africa, although its range is fractured into little areas now. It’s happy in a number of habitats, including rainforests and savannas.

The zoo came up with four name choices for their calf and invited people to vote for which name they liked best. The winning name was announced just a few days ago as this episode goes live, Kipekee. It means “unique” in Swahili, the official language of Kenya.

Kipekee is healthy and active, and the zoo reports she was immediately accepted by her mother and all the other giraffes as just a regular baby. I guess giraffes understand that what you look like isn’t nearly as important as how you act, and Kipekee acts like a curious little baby giraffe.

In a lot of news reports, you’ll hear that Kipekee is the only unspotted giraffe seen since 1972, when one was born in a zoo in Japan, and that she’s likely the only unspotted giraffe alive in the entire world right now. But then, only a matter of hours before this episode goes live, because I took forever to start working on it, the Giraffe Conservation Foundation dropped a post on their Facebook page. It has a photo of a giraffe mama and baby running along in the wild in Namibia in Africa. And the baby giraffe HAS NO SPOTS!

As of right now, that’s all we know about the other spotless giraffe calf, but I’ll definitely keep you posted in future episodes.

Speaking of updates, reading about the giraffe without spots reminded me of an episode we released at the end of 2019, about Tira the zebra. Instead of stripes like ordinary zebras, Tira had spots!

Tira was first observed by a tour guide in Kenya in September of 2019. The guide’s name is Antony Tira and the foal was named after him. Little Tira was just a baby back then, living with her herd on a national reserve.

But then, according to internet rumor, something awful happened. Little Tira and her mom were captured, put on a truck to smuggle them out of the reserve, and sold to a private collector! There were even pictures of the pair in a truck. And sure enough, Tira was nowhere to be found in the wild.

But things aren’t always what they seem, especially on the internet. Because amazingly, just like little Kipekee being born at about the same time as another super-rare spotless giraffe, little Tira was born at about the same time as another spotted zebra. The second foal was a boy who was observed in South Africa. But unlike Tira, who was safely in protected land, the second foal wasn’t so lucky. A veterinarian named Craig Bull was hired to relocate the mother and baby to a safer location, which he did with the help of his team. People saw pictures of a spotted zebra baby and its mother in a truck and jumped to the wrong conclusions.

Zebras are famous for their black and white stripes, but on very rare occasions, a genetic mutation causes the ordinary striped pattern to be broken up so that it looks like spots. Most people think zebras are white animals with black stripes, but that’s actually backwards. Zebras are black with white stripes, so when the stripe pattern is broken up, the zebra looks like a black or brown animal with white spots and streaks. Every zebra’s pattern is unique, just as every giraffe’s spot pattern is unique, so a close look at the photo of the spotted zebra in a truck shows it’s obviously not the same animal as Tira. Their spot patterns are totally different.

So what did happen to Tira? Why did she disappear? Is she even still alive?

On September 29, 2019, when Tira was probably only a few weeks old, a wildlife photographer spotted her crossing the Sand River into Serengeti Park in Tanzania with her herd. Zebra herds migrate to new pastures periodically, along with other animals like wildebeest, so that wasn’t unusual. But because life in the wild is hard for young animals, no one was really surprised when Tira wasn’t seen again.

At least, she wasn’t seen again until August of 2021, when a tour guide and photographer pair saw her in the middle of the herd. She had grown to the size of a typical two-year-old filly and looked healthy. As is common in zebras, she was still with her mother and still nursing occasionally.

That’s all we know now, but if Tira survived for two years, she’ll probably be just fine. She would be four years old now, basically a young mare, and she might even have a baby of her own by now. Hopefully some lucky photographer will see her again soon and give us an update on everyone’s favorite spotted zebra.

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 342: Giant Snails and Giant Crabs

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Thanks to Tobey and Anbo for their suggestions this week! We’re going to learn about some giant invertebrates!

Further reading:

The Invasive Giant African Land Snail Has Been Spotted in Florida

A very big shell:

The giant African snail is pretty darn giant [photo from article linked above]:

The largest giant spider crab ever measured, and a person:

Show transcript:

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

This week we’re going to learn about some giant invertebrates, suggested by Tobey and Anbo. Maybe they’re not as big as dinosaurs or whales, but they’re surprisingly big compared to most invertebrates.

Let’s start with Tobey’s suggestion, about a big gastropod. Gastropods include slugs and snails, and while Tobey suggested the African trumpet snail specifically, I couldn’t figure out which species of snail it is. But it did lead me to learning a lot about some really big snails.

The very biggest snail known to be alive today is called the Australian trumpet snail, Syrinx aruanus. This isn’t the kind of snail you’d find in your garden, though. It’s a sea snail that lives in shallow water off the coast of northern Australia, around Papua New Guinea, and other nearby areas. It has a coiled shell that’s referred to as spindle-shaped, because the coils form a point like the spindle of a tower. It’s a pretty common shape for sea snails and you’ve undoubtedly seen this kind of seashell before if you’ve spent any time on the beach. But unless you live in the places where the Australian trumpet lives, you probably haven’t seen a seashell this size. The Australian trumpet’s shell can grow up to three feet long, or 91 cm. Not only is this a huge shell, the snail itself is really heavy. It can weigh as much as 31 lbs, or 14 kg, which is as heavy as a good-sized dog.

The snail eats worms, but not just any old worms. If you remember episode 289, you might remember that Australia is home to the giant beach worm, a polychaete worm that burrows in the sand between high and low tide marks. It can grow as much as 8 feet long, or 2.4 meters, and probably longer. Well, that’s the type of worm the Australian trumpet likes to eat, along with other worms. The snail extends a proboscis into the worm’s burrow to reach the worm, but although I’ve tried to find out how it actually captures the worm in order to eat it, this seems to be a mystery. Like other gastropods, the Australian trumpet eats by scraping pieces of food into its mouth using a radula. That’s a tongue-like structure studded with tiny sharp teeth, and the Australian trumpet has a formidable radula. Some other sea snails, especially cone snails, are able to paralyze or outright kill prey by injecting it with venom via a proboscis, so it’s possible the Australian trumpet does too. The Australian trumpet is related to cone snails, although not very closely.

Obviously, we know very little about the Australian trumpet, even though it’s not hard to find. The trouble is that its an edible snail to humans and humans also really like those big shells and will pay a lot for them. In some areas people have hunted the snail to extinction, but we don’t even know how common it is overall to know if it’s endangered or not.

Tobey may have been referring to the giant African snail, which is probably the largest living land snail known. There are several snails that share the name “giant African snail,” and they’re all big, but the biggest is Lissachatina fulica. It can grow more than 8 inches long, or 20 cm, and its conical shell is usually brown and white with pretty banding in some of the whorls. It looks more like the shell of a sea snail than a land snail, but the shell is incredibly tough.

The giant African snail is an invasive species in many areas. Not only will it eat plants down to nothing, it will also eat stucco and concrete for the minerals they contain. It even eats sand, cardboard, certain rocks, bones, and sometimes other African giant snails, presumably when it runs out of trees and houses to eat. It can spread diseases to plants, animals, and humans, which is a problem since it’s also edible.

Like many snails, the African giant snail is a simultaneous hermaphrodite, meaning it can produce both sperm and eggs. It can’t self-fertilize its own eggs, but after mating a snail can keep any unused sperm alive in its body for up to two years, using it to fertilize eggs during that whole time, and it can lay up to 200 eggs five or six times a year. In other words, it only takes a single snail to produce a wasteland of invasive snails in a very short amount of time.

In June 2023, some African giant snails were found near Miami, Florida and officials placed the whole area under agricultural quarantine. That means no one can move any soil or plants out of the area without permission, since that could cause the snails to spread to other places. Meanwhile, officials are working to eradicate the snails. Other parts of Florida are also under the same quarantine after the snails were found the year before. Sometimes when people go on vacation in the Caribbean they bring back garden plants, without realizing that the soil in the pot contains giant African snail eggs, because the giant African snail is also an invasive species throughout the Caribbean.

Next, Anbo wanted to learn about the giant spider crab, also called the Japanese spider crab because it lives in the Pacific Ocean around Japan. It is indeed a type of crab, which is a crustacean, which is an arthropod, and it has the largest legspan of any arthropod known. Its body can grow 16 inches across, or 40 cm, and it can weigh as much as 42 pounds, or 19 kg, which is almost as big as the biggest lobster. But its legs are really really really long. Really long! It can have a legspan of 12 feet across, or 3.7 meters! That includes the claws at the end of its front legs. Most individual crabs are much smaller, but since crustaceans continue to grow throughout their lives, and the giant spider crab can probably live to be 100 years old, there’s no reason why some crabs couldn’t be even bigger than 12 feet across. Its long legs are delicate, though, and it’s rare to find an old crab that hasn’t had an injury to at least one leg.

The giant spider crab is orange with white spots, sort of like a koi fish but in crab form. Its carapace is also bumpy and spiky. You wouldn’t think a crab this size would need to worry about predators, but it’s actually eaten by large octopuses. The crab sticks small organisms like sponges and kelp to its carapace to help camouflage it.

The giant spider crab is considered a delicacy in some places, which has led to overfishing. It’s now protected in Japan, where people are only allowed to catch the crabs during part of the year. This allows the crabs to safely mate and lay eggs.

There’s another species called the European spider crab that has long legs, but it’s nowhere near the size of the giant spider crab. Its carapace width is barely 8 ½ inches across, or 22 cm, and its legs are about the same length. Remember that the giant spider crab’s legs can be up to six feet long each, or 1.8 meters. While the European spider crab does resemble the giant spider crab in many ways, it’s actually not closely related to it. They two species belong to separate families.

The giant spider crab spends most of its time in deep water, although in mating season it will come into shallower water. It uses its long legs to walk around on the sea floor, searching for food. It’s an omnivore that eats pretty much anything it can find, including plants, dead animals, and algae, but it will also use its claws to open mollusk shells and eat the animals inside. It prefers rocky areas of the sea floor, since its bumpy carapace blends in well among rocks.

Scientists report that the giant spider crab is mostly good-natured, even though it looks scary. Some big aquariums keep giant spider crabs, and the aquarium workers say the same thing. But it does have strong claws, and if it feels threatened it can seriously injure divers. I shouldn’t need to remind you not to pester a crab with a 12-foot legspan.

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 338: Updates 6 and an Arboreal Clam!?!

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This week we have our annual updates and corrections episode, and at the end of the episode we’ll learn about a really weird clam I didn’t even think was real at first.

Thanks to Simon and Anbo for sending in some corrections!

Further reading:

Lessons on transparency from the glass frog

Hidden, never-before-seen penguin colony spotted from space

Rare wild asses spotted near China-Mongolia border

Aye-Ayes Use Their Elongated Fingers to Pick Their Nose

Homo sapiens likely arose from multiple closely related populations

Scientists Find Earliest Evidence of Hominins Cooking with Fire

153,000-Year-Old Homo sapiens Footprint Discovered in South Africa

Newly-Discovered Tyrannosaur Species Fills Gap in Lineage Leading to Tyrannosaurus rex

Earth’s First Vertebrate Superpredator Was Shorter and Stouter than Previously Thought

252-Million-Year-Old Insect-Damaged Leaves Reveal First Fossil Evidence of Foliar Nyctinasty

The other paleo diet: Rare discovery of dinosaur remains preserved with its last meal

The Mongolian wild ass:

The giant barb fish [photo from this site]:

Enigmonia aenigmatica, AKA the mangrove jingle shell, on a leaf:

Show transcript:

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

This week is our annual updates and corrections episode, but we’ll also learn about the mangrove jingle shell, a clam that lives in TREES. A quick reminder that this isn’t a comprehensive updates episode, because that would take 100 years to prepare and would be hours and hours long, and I don’t have that kind of time. It’s just whatever caught my eye during the last year that I thought was interesting.

First, we have a few corrections. Anbo emailed me recently with a correction from episode 158. No one else caught this, as far as I can remember. In that episode I said that geckos don’t have eyelids, and for the most part that’s true. But there’s one family of geckos that does have eyelids, Eublepharidae. This includes the leopard gecko, and that lines up with Anbo’s report of having a pet leopard gecko who definitely blinked its eyes. This family of geckos are sometimes even called eyelid geckos. Also, Anbo, I apologize for mispronouncing your name in last week’s episode about shrimp.

After episode 307, about the coquí and glass frogs, Simon pointed out that Hawaii doesn’t actually have any native frogs or amphibians at all. It doesn’t even have any native reptiles unless you count sea snakes and sea turtles. The coqui frog is an invasive species introduced by humans, and because it has no natural predators in Hawaii it has disrupted the native ecosystem in many places, eating all the available insects. Three of the Hawaiian islands remain free of the frogs, and conservationists are working to keep it that way while also figuring out ways to get them off of the other islands. Simon also sent me the chapter of the book he’s working on that talks about island frogs, and I hope the book is published soon because it is so much fun to read!

Speaking of frogs, one week after episode 307, an article about yet another way the glass frog is able to hide from predators was published in Science. When a glass frog is active, its blood is normal, but when it settles down to sleep, the red blood cells in its blood collect in its liver. The liver is covered with teensy guanine crystals that scatter light, which hides the red color from view. That makes the frog look even more green and leaf-like!

We’ve talked about penguins in several episodes, and emperor penguins specifically in episode 78. The emperor penguin lives in Antarctica and is threatened by climate change as the earth’s climate warms and more and more ice melts. We actually don’t know all that much about the emperor penguin because it lives in a part of the world that’s difficult for humans to explore. In December 2022, a geologist named Peter Fretwell was studying satellite photos of Antarctica to measure the loss of sea ice when he noticed something strange. Some of the ice had brown stains.

Dr Fretwell knew exactly what those stains were: emperor penguin poop. When he obtained higher-resolution photos, he was able to zoom in and see the emperor penguins themselves. But this wasn’t a colony he knew about. It was a completely undiscovered colony.

In episode 292 we talked about a mystery animal called the kunga, and in that episode we also talked a lot about domestic and wild donkeys. We didn’t cover the Mongolian wild ass in that one, but it’s very similar to wild asses in other parts of the world. It’s also called the Mongolian khulan. It used to be a lot more widespread than it is now, but these days it only lives in southern Mongolia and northern China. It’s increasingly threatened by habitat loss, climate change, and poaching, even though it’s a protected animal in both Mongolia and China.

In February of 2023, a small herd of eight Mongolian wild asses were spotted along the border of both countries, in a nature reserve. A local herdsman noticed them first and put hay out to make sure the donkeys had enough to eat. The nature reserve has a water station for wild animals to drink from, and has better grazing these days after grassland ecology measures were put into place several years ago.

In episode 233 we talked about the aye-aye of Madagascar, which has weird elongated fingers. Its middle finger is even longer and much thinner than the others, which it uses to pull invertebrates from under tree bark and other tiny crevices. Well, in October of 2022 researchers studying aye-ayes started documenting another use for this long thin finger. The aye-ayes used it to pick their noses. It wasn’t just one aye-aye that wasn’t taught good manners, it was widespread. And I hope you’re not snacking while I tell you this, the aye-aye would then lick its finger clean. Yeah. But the weirdest thing is that the aye-aye’s thin finger is so long that it can potentially reach right through the nose right down into the aye-aye’s throat.

It’s pretty funny and gross, but wondering why some animals pick their noses is a valid scientific question. A lot of apes and monkeys pick their noses, as do humans (not that we admit it most of the time), and now we know aye-ayes do too. The aye-aye is a type of lemur and therefore a primate, but it’s not very closely related to apes and monkeys. Is this just a primate habit or is it only seen in primates because we have fingers that fit into our nostrils? Would all mammals pick their nose if they had fingers that would fit up in there? Sometimes if you have a dried snot stuck in your nose, it’s uncomfortable, but picking your nose can also spread germs if your fingers are dirty. So it’s still a mystery why the aye-aye does it.

A recent article in Nature suggests that Homo sapiens, our own species, may have evolved not from a single species of early human but from the hybridization of several early human species. We already know that humans interbred with Neandertals and Denisovans, but we’re talking about hybridization that happened long before that between hominin species that were even more closely related.

The most genetically diverse population of humans alive today are the Nama people who live in southern Africa, and the reason they’re so genetically diverse is that their ancestors have lived in that part of Africa since humans evolved. Populations that migrated away from the area, whether to different parts of Africa or other parts of the world, had a smaller gene pool to draw from as they moved farther and farther away from where most humans lived.

Now, a new genetic study of modern Nama people has looked at changes in DNA that indicate the ancestry of all humans. The results suggest that before about 120,000 to 135,000 years ago, there was more than one species of human, but that they were all extremely closely related. Since these were all humans, even though they were ancient humans and slightly different genetically, it’s probable that the different groups traded with each other or hunted together, and undoubtedly people from different groups fell in love just the way people do today. Over the generations, all this interbreeding resulted in one genetically stable population of Homo sapiens that has led to modern humans that you see everywhere today. To be clear, as I always point out, no matter where people live or what they look like, all people alive today are genetically human, with only minor variations in our genetic makeup. It’s just that the Nama people still retain a lot of clues about our very distant ancestry that other populations no longer show.

To remind everyone how awesome out distant ancestors were, here’s one new finding of how ancient humans lived. We know that early humans and Neandertals were cooking their food at least 170,000 years ago, but recently archaeologists found the remains of an early hominin settlement in what is now Israel where people were cooking fish 780,000 years ago. There were different species of fish remains found along with the remains of cooking fires, and some of the fish are ones that have since gone extinct. One was a carp-like fish called the giant barb that could grow 10 feet long, or 3 meters.

In other ancient human news, the oldest human footprint was discovered recently in South Africa. You’d think that we would have lots of ancient human footprints, but that’s actually not the case when it comes to footprints more than 50,000 years old. There are only 14 human footprints older than that, although there are older footprints found made by ancestors of modern humans. The newly discovered footprint dates to 153,000 years ago.

It wouldn’t be an updates episode without mentioning Tyrannosaurus rex. In late 2022 a newly discovered tyrannosaurid was described. It lived about 76 million years ago in what is now Montana in the United States, and while it wasn’t as big as T. rex, it was still plenty big. It probably stood about seven feet high at the hip, or a little over 2 meters, and might have been 30 feet long, or 9 meters. It probably wasn’t a direct ancestor of T. rex, just a closely related cousin, although we don’t know for sure yet. It’s called Daspletosaurus wilsoni and it shows some traits that are found in older Tyrannosaur relations but some that were more modern at the time.

Dunkleosteus is one of a number of huge armored fish that lived in the Devonian period, about 360 million years ago. We talked about it way back in episode 33, back in 2017, and at that time paleontologists thought Dunkleosteus terrelli might have grown over 30 feet long, or 9 meters. It had a heavily armored head but its skeleton was made of cartilage like a shark’s, and cartilage doesn’t generally fossilize, so while we have well-preserved head plates, we don’t know much about the rest of its body.

With the publication in early 2023 of a new study about dunkleosteus’s size, we’re pretty sure that 30 feet was a huge overestimation. It was probably less than half that length, maybe up to 13 feet long, or almost 4 meters. Previous size estimates used sharks as size models, but dunkleosteus would have been shaped more like a tuna. Maybe you think of tuna as a fish that makes a yummy sandwich, but tuna are actually huge and powerful predators that can grow up to 10 feet long, or 3 meters. Tuna are also much heavier and bigger around than sharks, and that was probably true for dunkleosteus too. The study’s lead even says dunkleosteus was built like a wrecking ball, and points out that it was probably the biggest animal alive at the time. I’m also happy to report that people have started calling it chunk-a-dunk.

We talked about trace fossils in episode 103. Scientists can learn a lot from trace fossils, which is a broad term that encompasses things like footprints, burrows, poops, and even toothmarks. Recently a new study looked at insect damage on leaves dating back 252 million years and learned something really interesting. Some modern plants fold up their leaves at night, called foliar nyctinasty, which is sometimes referred to as sleeping. The plant isn’t asleep in the same way that an animal falls asleep, but “sleeping” is a lot easier to say than foliar nyctinasty. Researchers didn’t know if folding leaves at night was a modern trait or if it’s been around for a long time in some plants. Lots of fossilized leaves are folded over, but we can’t tell if that happened after the leaf fell off its plant or after the plant died.

Then a team of paleontologists from China and Sweden studying insect damage to leaves noticed that some leaves had identical damage on both sides, exactly as though the leaf had been folded and an insect had eaten right through it. That’s something that happens in modern plants when they’re asleep and the leaves are folded closed.

The team looked at fossilized leaves from a group of trees called gigantopterids, which lived between 300 and 250 million years ago. They’re extinct now but were advanced plants at the time, some of the earliest flowering plants. They also happen to have really big leaves that often show insect damage. The team determined that the trees probably did fold their leaves while sleeping.

In episode 151 we talked about fossils found with other fossils inside them. Basically it’s when a fossil is so well preserved that the contents of the dead animal’s digestive system are preserved. This is incredibly rare, naturally, but recently a new one was discovered.

Microraptor was a dinosaur that was only about the size of a modern crow, one of the smallest dinosaurs, and it probably looked a lot like a weird bird. It could fly, although probably not very well compared to modern birds, and in addition to front legs that were modified to form wings, its back legs also had long feathers to form a second set of wings.

Several exceptionally well preserved Microraptor fossils have been discovered in China, some of them with parts of their last meals in the stomach area, including a fish, a bird, and a lizard, so we knew they were generalist predators when it came to what they would eat. Now we have another Microraptor fossil with the fossilized foot of a mammal in the place where the dinosaur’s stomach once was. So we know that Microraptor ate mammals as well as anything else it could catch, although we don’t know what kind of mammal this particular leg belonged to. It may be a new species.

Let’s finish with the mangrove jingle shell. I’ve had it on the list for a long time with a lot of question marks after it. It’s a clam that lives in trees, and I actually thought it might be an animal made up for an April fool’s joke. But no, it’s a real clam that really does live in trees.

The mangrove jingle shell lives on the mangrove tree. Mangroves are adapted to live in brackish water, meaning a mixture of fresh and salt water, or even fully salt water. They mostly live in tropical or subtropical climates along coasts, and especially like to live in waterways where there’s a tide. The tide brings freshly oxygenated water to its roots. A mangrove tree needs oxygen to survive just like animals do, but it has trouble getting enough through its roots when they’re underwater. Its root system is extensive and complicated, with special types of roots that help it stay upright when the tide goes out and special roots called pneumatophores, which stick up above the water or soil and act as straws, allowing the tree to absorb plenty of oxygen from the air even when the rest of the root system is underwater. These pneumatophores are sometimes called knees, but different species of mangrove have different pneumatophore shapes and sizes.

One interesting thing about the mangrove tree is that its seeds actually sprout while they’re still attached to the parent tree. When it’s big enough, the seedling drops off its tree into the water and can float around for a long time before it finds somewhere to root. If can even survive drying out for a year or more.

The mangrove jingle shell clam lives in tropical areas of the Indo-Pacific Ocean, and is found throughout much of coastal southeast Asia all the way down to parts of Australia. It grows a little over one inch long, or 3 cm, and like other clams it finds a place to anchor itself so that water flows past it all the time and it can filter tiny food particles from the water. It especially likes intertidal areas, which happens to be the same area that mangroves especially like.

Larval jingle shells can swim, but they need to find somewhere solid to anchor themselves as they mature. When a larva finds a mangrove root, it attaches itself and grows a domed shell. If it finds a mangrove leaf, since mangrove branches often trail into the water, it attaches itself to the underside and grows a flatter shell. Clams attached to leaves are lighter in color than clams attached to roots or branches. Fortunately, the mangrove is an evergreen tree that doesn’t drop its leaves every year.

So there you have it. Arboreal clams! Not a hoax or an April fool’s joke.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 332: Hunting Partners and Mutualism

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Thanks to Vaughn and Jan for their suggestions this week! We’re going to learn about mutualism of various types.

Further reading:

The odd couple: spider-frog mutualism in the Amazon rainforest

What Birds, Coyotes, and Badgers Know About Teamwork

Octopuses punch fishes during collaborative interspecific hunting events

An Emotional Support Dog Is the Only Thing That Chills Out a Cheetah

Buddies [picture from the first link above]:

The honeyguide bird:

Cheetahs and dogs can be friends:

Show transcript:

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

This week we’re going to learn about a topic that I’ve been wanting to cover for a long time, mutualism. It’s a broad topic so we won’t try to cover everything about it in this episode, just give an overview with some examples. Vaughn suggested symbiotic behavior ages ago, and Jan gave me a great example of this, also ages ago, so thanks to both of them!

Mutualism is similar to other terms, including symbiosis, often referred to as “a symbiotic relationship.” I’m using mutualism as a general term, but if you want to learn more you’ll quickly find that there are lots of terms referring to different interspecies relationships. Basically we’re talking about two unrelated organisms interacting in a way that’s beneficial to both. This is different from commensalism, where one organism benefits and the other doesn’t but also isn’t harmed, and parasitism, where one organism benefits and the other is harmed.

We’ll start with the suggestion from Jan, who alerted me to this awesome pair of animals. Many different species have developed this relationship, but we’ll take as our specific example the dotted humming frog that lives in parts of western South America.

The dotted humming frog is a tiny nocturnal frog that barely grows more than half an inch long from snout to vent, or about 2 cm. It lives in swamps and lowland forests and spends most of the day in a burrow underground. It comes out at night to hunt insects, especially ants. It really loves ants and is considered an ant specialist. That may be why the dotted humming frog has a commensal relationship with a spider, the Colombian lesserblack tarantula.

The tarantula is a lot bigger than the frog, with its body alone almost 3 inches long, or 7 cm. Its legspan can be as much as 8 and a half inches across, or 22 cm. It’s also nocturnal and spends the day in its burrow, coming out at night to hunt insects and other small animals, although not ants. It’s after bigger prey, including small frogs. But it doesn’t eat the dotted humming frog. One or even more of the frogs actually lives in the same burrow as the tarantula and they come out to hunt in the evenings at the same time as their spider roommate.

So what’s going on? Obviously the frog gains protection from predators by buddying up with a tarantula, but why doesn’t the tarantula just eat the frog? Scientists aren’t sure, but the best guess is that the frog protects the spider’s eggs from ants. Ants like to eat invertebrate eggs, but the dotted humming frog likes to eat ants, and as it happens the female Colombian lesserblack tarantula is especially maternal. She lays about 100 eggs and carries them around in an egg sac. When the babies hatch, they live with their mother for up to a year, sharing food and burrow space.

This particular tarantula also gets along with another species of frog that also eats a lot of ants. Researchers think the spiders distinguish the frogs by smell. The ant-eating frogs apparently smell like friends, or at least useful roommates, while all other frogs smell like food. Or, of course, it’s possible that the ant-eating frogs smell and taste bad to the spider. Either way, both the frogs and the tarantulas benefit from the relationship–and this pairing of tiny frogs and big spiders is one that’s actually quite common throughout the world.

Mutualism is everywhere, from insects gathering nectar to eat while pollenating flowers at the same time, to cleaner fish eating parasites from bigger fish, to birds eating fruit and pooping out seeds that then germinate with a little extra fertilizer. Many mutualistic relationships aren’t obvious to us as humans until we’ve done a lot of careful observations, which is why it’s so important to protect not just a particular species of animal but its entire ecosystem. We don’t always know what other animals and plants that animal depends on to survive, and vice versa.

Sometimes an individual animal will work together with an individual of another species to find food. This may not happen all the time, just when circumstances are right. Sometimes, for example, a coyote will pair up with a badger to hunt. The coyote is closely related to wolves and can run really fast, while the American badger can dig really fast. Both are native to North America. They also both really like to eat prairie dogs, a type of rodent that can run really fast and lives in a burrow. Some prairie dog tunnels can extend more than 30 feet, or 10 meters, with multiple exits. The badger can dig into the burrow and if the prairie dog leaves through one of the exits, the coyote chases after it. When one of the predators catches the prairie dog, they don’t share the meal but they will often continue to hunt together until both are able to eat.

Other animals hunt together too. Moray eels will sometime pair up with a fish called the grouper in a similar way as the coyote and badger. The grouper is a fast swimmer while the eel can wriggle into crevices in rocks or coral. The grouper will swim up to the eel and shake its head rapidly to initiate a hunt, and if the grouper has seen a prey item disappear into a crevice, it will lead the eel to the crevice and shake its head at it again.

Groupers also sometimes pair up with octopuses to hunt together, as will some other species of fish. Like the eel, the octopus can enter crevices to chase an animal that’s trying to hide. But the octopus isn’t always a good hunting partner, because if the grouper catches a fish, sometimes the octopus will punch the grouper and steal its fish. Not cool, octopus.

Birds have mutualistic relationships too, including the honeyguide that lives in parts of Africa and Asia. It’s a little perching bird that’s mostly gray and white or brown and white, with the males of some species having yellow markings. It eats insects, spiders, and other invertebrates, and it especially likes bee larvae. But it’s just a little bird and can’t break open wild honeybee hives by itself.

Some species of honeyguide that live in Africa have figured out that humans can break open beehives. When the honeyguide bird finds a beehive, it will fly around until it hears the local people’s hunting calls. The bird will then respond with a distinct call of its own, alerting the people, and will guide them to the beehive. This has been going on for thousands of years. The humans gather the honey, the honeyguide feasts on the bee larvae and wax, and everyone has a good day except the bees.

The honeyguide is also supposed to guide the honey badger to beehives, but there’s no definitive evidence that this actually happens. Honey badgers do like to eat honey and bee larvae, though, and when a honey badger breaks open a beehive, honeyguides and other birds will wait until it’s eaten what it wants and will then pick through the wreckage for any food the badger missed. But the honeyguide might lead the honey badger to the hive, we just don’t know for sure.

Humans sometimes even help other animals into a commensal relationship. Vaughn gave me an example of a cheetah in a zoo who became best friends with a dog. This hasn’t just happened once, it’s happened lots of times because zookeepers have found that it helps cheetahs kept in captivity. Cheetahs are social animals but sometimes a zoo doesn’t have a good companion for a cheetah cub. The cub could be in danger from older, unrelated cheetahs, but a cheetah all on its own is prone to anxiety. It’s so important for a cheetah to have a sibling that if a mother cheetah only has one cub, or if all but one cub dies, a lot of times she’ll abandon the single cub. If this happens in the wild, it’s sad, but if it happens in captivity the zoo needs to help the cub.

To do this, the zoo will pair the cub with a puppy of a sociable, large breed of dog, such as a Labrador or golden retriever. The cub and the puppy grow up together. The cheetah has a mellow friend who helps alleviate its anxiety, and the dog has a friend who’s really good at playing chase.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way.

Thanks for listening!

Episode 330: Vintana and Tiarajudens

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Thanks to Lorenzo for suggesting Tiarajudens! We’ll learn about it this week along with another extinct animal, Vintana.

Further reading:

Funky facial flanges [the skull picture below comes from this site]

First Postcranial Fossils of Rare Gondwanatherian Mammal Unearthed in Madagascar

The Earliest Saberteeth Were for Fighting, Not Biting [the skeleton picture below comes from this site]

Vintana’s skull had weird jugal flanges:

Tiarajudens had saber teeth as well as palatal teeth:

Show transcript:

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

Just last month we had an episode about the tenrec and an extinct animal called Adalatherium. At the end of that episode, I said something I say a lot, that we don’t know very much about it or the other ancient mammals that lived at the time, and that I hoped we would find some new fossils soon. Well, guess what! A paper about a newly discovered Gondwanathere fossil was published just a few days ago as this episode goes live. Rather than save it for the updates episode later this summer, let’s learn about an animal named Vintana sertichi, along with a suggestion from Lorenzo for another extinct animal.

As you may remember from episode 324, Adalatherium is a member of a group of animals called Gondwanatheria, which arose in the southern hemisphere around the time that the supercontinent Gondwana was breaking apart. We only have a few fossils of these animals so paleontologists still don’t know how they’re related, although we do know they’re not related to the mammals living today. Every new specimen found of these rare mammals helps scientists fill the gaps in our knowledge. That’s what happened with Vintana.

Vintana lived at the end of the Cretaceous, until the asteroid strike about 66 million years ago that killed off the non-avian dinosaurs and a whole lot of other animals, probably including Vintana. The first fossilized specimen was a skull found in Madagascar and described in 2014. It was really well preserved, which allowed scientists to learn a lot about the animal.

Vintana was an active animal that ate plants. It had large eyes and a good sense of smell and hearing, so its ears might have been fairly large too. Its face probably looked a lot like a big rodent’s face, but the skull itself had a weird feature. The cheekbones extended downward on each side next to the jaw, and these extensions are called jugal flanges. They would have allowed for the attachment of really big jaw muscles. That suggests that Vintana could probably give you a nasty bite, not that you need to worry about that unless you find a time machine. It might also mean that Vintana ate tough plants that required a lot of chewing.

Vintana probably looked a lot like a groundhog, or marmot, which we talked about recently in episode 327. It wasn’t related to the groundhog, though, and was bigger too. Scientists estimate it weighed about 20 lbs, or 9 kg.

The fossil specimen of Adalatherium that we talked about in episode 324 was discovered in Madagascar in 2020. When a tail vertebra from another mammal was found in the same area, researchers scanned and compared it to Adalatherium’s vertebrae. They were similar but not an exact match, plus the new bone was almost twice as large as the same bone in Adalatherium’s spine. It matched the size of Vintana and was assigned to that species. Vintana was probably related to Adalatherium but was bigger and had a shorter, wider tail. And as of right now, that’s just about all we know about it.

Next, let’s learn about another extinct animal, this one suggested by Lorenzo. Lorenzo gave me a bunch of great suggestions and I picked this one to pair with Vintana, because otherwise this episode would have been really short. Vintana lived at the end of the dinosaurs, but Tiarajudens lived long before the dinosaurs evolved, around 260 million years ago.

Tiarajudens was a therapsid, a group that eventually gave rise to mammals although it’s not a direct ancestor of mammals. Technically it’s an anomodont. We don’t have a complete skeleton so we don’t know for sure how big it was, but we do have a skull and some leg bones so we know it was about the same size or a little bigger than a big dog. There are only two species known, one from what is now South America and one from what is now Africa, but 260 million years ago those two landmasses were connected and were part of the supercontinent Gondwana.

Tiarajudens had weird teeth even compared to other anomodonts. It had a pair of saber teeth that resembled the tusks found in later anomodonts, but they weren’t really tusks. They were big fangs that grew from the upper jaw and jutted down out of the mouth well past the bottom of the jaw. Later anomodonts probably used their tusks to dig up plants, but there aren’t wear marks on Tiarajudens’s saber teeth that would indicate it used them for digging. Many paleontologists think it used them for defense and to fight other Tiarajudenses over mates or territory. We don’t know if the saber teeth were present in all individuals, since we’ve only found a few specimens.

Tiarajudens also had palatal teeth. These days palatal teeth are mostly found in amphibians, especially frogs. Palatal teeth grow down from the roof of the mouth and Tiarajudens’s were flat like molars. We haven’t found a lower jaw yet so we don’t know what the bottom teeth looked like, but from the wear marks on the upper teeth, it was clear that Tiarajudens was actually chewing its food. That was really unusual among all animals at the time, and in fact Tiarajudens is one of the first animals to really chew its food instead of giving it a chomp or two and swallowing it mostly whole. It ate plants, probably tough ones that required a lot of chewing.

So what did Tiarajudens look like beyond its teeth? It probably resembled a bulky four-legged dinosaur with a short tail, but it may have had whiskers. That’s as much as we know right now, because Tiarajudens was not only an early therapsid, it was different in many ways from most other therapsids known. For instance, it had what are called gastralia, or belly ribs, which were once common in tetrapods. Some dinosaurs had gastralia, including T. rex, but most therapsids didn’t. These days crocodiles and their relations still have gastralia, and so does the tuatara, but most animals don’t.

Both Tiarajudens and Vintana were unusual animals that we just don’t know much about. Let’s hope that changes soon and scientists find more fossils of both. I’ll keep you updated.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 329: Manatees and a Surprise Sloth

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Thanks to Alexandra and Pranav for their suggestions this week! Let’s learn about manatees and sloths, including a surprising extinct sloth.

Further reading:

Sloths in the Water

A West Indian manatee:

A three-toed sloth:

Show transcript:

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

This week we have a suggestion from Alexandra and Pranav, who wanted an episode about manatees. We’ll also talk about another marine mammal, a weird extinct one you may never have heard of.

The manatee is also called the sea cow, because it sort of slightly resembles a cow and it grazes on plants that grow underwater. It’s a member of the order Sirenia, which includes the dugong, and sirenians are probably most closely related to the elephant. This sounds ridiculous at first, but there are a lot of physical similarities between the manatee and the elephant. Their teeth are very similar, for instance, even if the manatee doesn’t grow tusks. The elephant has a pair of big chewing teeth on each side of its mouth that look more like the bottoms of running shoes than ordinary teeth. Every so many years, the four molars in an elephant’s mouth start to get pushed out by four new molars. The new teeth grow in at the back of the mouth and start moving forward, pushing the old molars farther forward until they fall out. The manatee has this same type of tooth replacement, although its teeth aren’t as gigantic as the elephant’s teeth. The manatee also has hard ridged pads on the roof of its mouth that help it chew its food.

Female manatees are larger than males on average, and a really big female manatee can grow over 15 feet long, or 4.6 meters. Most manatees are between 9 and 10 feet long, or a little less than 3 meters. Its body is elongated like a whale, but unlike a whale it’s slow, usually only swimming about as fast as a human can swim. Its skin is gray or brown although often it has algae growing on it that helps camouflage it. The end of the manatee’s tail looks like a rounded paddle, and it has front flippers but no rear limbs. Its face is rounded with a prehensile upper lip covered with bristly whiskers, which it uses to find and gather water plants.

Every so often a manatee will eat a little fish, apparently on purpose. Since most herbivorous animals will eat meat every so often, this isn’t unusual. Mostly, though, the manatee spends almost all of its time awake eating plants, often from the bottom of the waterway where it lives. It lives in shallow water and will use its flippers to walk itself along the bottom, and also uses its flippers to dig up plants. Its upper lip is divided in two like the upper lips of many animals, which you can see in a dog or cat as that little line connecting the bottom of the nose to the upper lip. In the manatee, though, both sides of the lips have a lot of muscles and can move independently.

There are three species of manatee alive today: the West Indian manatee that lives in the Gulf of Mexico down to the eastern coast of northern South America, the Amazonian manatee that lives exclusively in fresh water in the Amazon basin, and the West African manatee that lives in brackish and fresh water. Sometimes the West Indian manatee will also move into river systems to find food.

Back in episode 153 we talked about the Florida manatee, which is a subspecies of West Indian manatee. In the winter it mostly lives around Florida but in summer many individuals travel widely. It’s sometimes found as far north as Massachusetts along the Atlantic coast, and as far west as Texas in the Gulf of Mexico, but despite its size, the manatee doesn’t have a lot of blubber or fat to keep it warm. The farther away it travels from warm water, the more likely it is to die of cold.

In the 1970s there were only a few hundred Florida manatees alive and it nearly went extinct. It was listed as an endangered species and after a lot of effort by a lot of different conservation groups, it’s now only considered threatened, but it’s still vulnerable to habitat loss, injuries from boats, and getting tangled in fishing gear and drowning. Occasionally a crocodile will eat a young manatee, but for the most part it’s so big, and lives in such shallow water, that most predators won’t bother it. It basically only has to worry about humans, and unfortunately humans still cause a lot of manatee deaths every year with boats.

A lot of times, a manatee that’s hit by a boat is only injured. There are several rehabilitation centers in the United States, where an injured manatee can be treated by veterinarians until it’s healed and can be reintroduced into the wild.

One other detail that makes the manatee similar to the elephant is its flippers, which is probably not what you expected me to say. Most manatees have toenails on their flippers that closely resemble the nails on elephant feet. The exception is the Amazonian manatee that doesn’t have toenails at all.

A lot of the food the Amazonian manatee eats actually floats on the surface of the rivers where it lives, and it will also eat fruit that drops into the water. Because the Amazon basin is subject to a dry season where there’s not a lot of food, the manatee eats a lot when it can to build up fat reserves for later. During the dry season, it usually moves to the biggest lakes in the area as the rivers and shallower lakes dry up or get too shallow for the manatee to swim in. Since the manatee has a low metabolic rate, it can live off its fat reserves until the dry season is over.

One interesting thing about the manatee is that it only has six vertebrae in its neck. Almost all other mammals have seven, even giraffes. The exception is the two-toed sloth, which also has six, and the three-toed sloth, which has a varying number of neck vertebrae, up to nine in some species!

Pranav also wanted to learn about sloths, so let’s talk about them next. All sloths are native to Central and South America. The sloths living today live in forests, especially rainforests, and spend almost all their time in trees.

A sloth makes the manatee look like a speed demon. It spends most of its time hanging from its long claws beneath branches, eating leaves and other plant material, but when it does move, it does so extremely slowly. This helps it stay camouflaged from predators, because its fur contains algae that makes it look green, so a barely-moving green-furred sloth hanging from a tree just looks like a bunch of leaves. It does move from one tree to another to find fresh leaves, and once a week it climbs down from its tree to defecate and urinate on the ground. Yes, it only relieves itself once a week.

The sloth’s digestive tract is also extremely slow, which allows it to extract as much nutrition as possible from each leaf. It takes about a month for a sloth to fully digest one mouthful of food.

The three-toed sloth is about the size of a large cat while the two-toed sloth is slightly larger, maybe the size of a small to medium-sized dog. The two-toed sloth is nocturnal while the three-toed sloth is mostly diurnal. Even though they look and act very similar, the two types of sloth are not very closely related. Both have long curved claws and strong pulling muscles, although their pushing muscles are weak. This is why a sloth can’t walk like other animals; the muscles that would allow it to do so aren’t strong enough to support its own weight. And yet, it can hang from a branch and walk along it for as long as it needs to. I don’t think I could hang from a branch by my fingers for five minutes without having to let go.

Surprisingly, the sloth can also swim quite well, which allows it to find new trees even if there are streams or rivers in the way. But a few million years ago, a different type of sloth lived off the coast of western South America and did a whole lot of swimming. In fact, later species of Thalassocnus were probably fully marine mammals.

We talked about Thalassocnus briefly way back in episode 22. It was related to the giant ground sloths that were themselves related to the living three-toed sloths. The earliest Thalassocnus fossils are of semi-aquatic animals that grazed in shallow water. Fossils from more recent species show increasing adaptations to deeper water, including increased weight of the skeleton to help it stay underwater instead of bobbing up to the surface.

Thalassocnus eventually evolved a stiff, partially fused spine, which reflects the unusual way it moved around underwater. Instead of swimming the way a whale does, or even the way a dog or person does, it moved more like a hippopotamus. Hippos sort of bounce along underwater, using their feet to push off from the bottom. Thalassocnus probably did this too and used its long tail to help it maneuver.

Thalassocnus was a lot bigger than modern sloths. Even the smallest known species were the size of a big human, and the biggest species grew up to 11 feet long, or 3.3 meters. That biggest species was the one that lived most recently, up to about 1.5 million years ago, and researchers think it was fully aquatic. Its nostrils were on the top of its snout and it had prehensile lips to help it find plants underwater. Some researchers even think it could have had a short trunk something like a tapir. It had seven neck vertebrae, as in most other mammals.

There’s still a lot we don’t know about Thalassocnus, but because we have fossils of five different species that lived at different times, scientists are able to determine a lot about how it developed from a mostly terrestrial animal to a mostly or fully marine animal. The youngest species had smaller, weaker legs than the earlier ones, which suggests it didn’t use its legs to walk on land. It probably lived a lot like modern manatees, finding sea grasses and other plants on the sea floor in shallow water, but not able to swim very fast.

One last thing about the manatee is that it spends about half of its time asleep, and it sleeps underwater. It comes up for a breath every 15 minutes or so. Modern sloths sleep a lot too, around 15 hours a day. Chill sleepy friends.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or Podchaser, or just tell a friend. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 326: The Harpy Eagle and Friends

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Thanks to Eva and Anbo for suggesting the harpy eagle!

Further reading:

Crested Eagle Feeding a Post-Fledged Young Harpy Eagle

Harpy eagle with a food [By http://www.birdphotos.com – Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=3785263]:

The harpy eagle has great big feet and talons:

The harpy eagle with its feather crown raised [photo by Eric Kilby]:

The New Guinea harpy eagle looks similar to its South American cousin [By gailhampshire from Cradley, Malvern, U.K – New Guinea Harpy Eagle. Harpyopsis novaeguineae, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=86187611]:

Ruppell’s griffon vulture:

Show transcript:

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

We’ve been talking about a lot of mammals lately, so let’s have an episode about birds. Anbo suggested the harpy eagle not too long ago, and a much longer time ago Eva suggested the harpy eagle and other raptors.

The word raptor can be confusing because it refers to a type of small theropod dinosaur as well as a type of bird. When referring to a bird, the term raptor includes eagles, hawks, vultures, owls, and other birds of prey. And that includes the harpy eagle.

The harpy eagle lives throughout much of Central and South America, although not as far south as Patagonia. It has a wingspan up to about seven feet across, or over 2 meters, and like other raptors, females are larger than males. This isn’t an especially big wingspan for an eagle, but that’s because the harpy eagle hunts in forests and needs short, broad wings that allow it to maneuver through branches.

The harpy eagle is a beautiful bird. It has a light gray head and darker gray or black body, and is white underneath with delicate black stripes on its leg feathers, with broader stripes on its tail and wings. It has a black ring around its neck, huge yellow feet with enormous talons, and a black bill. Each talon, which is the term for a raptor’s claws, can be over 5 inches long, or 13 cm, while its feet in general are bigger than a grown man’s hand, even if the man has especially big hands.

Most striking of all is the harpy eagle’s crest, also sometimes referred to as a crown. The crown is made of long, rounded feathers and most of the time they don’t show very much. When a harpy eagle is alarmed, it raises the feather crown and poofs out the feathers on its face, which makes its head look bigger and sort of owl-shaped.

The harpy eagle mostly lives in lowland rainforests. It mates for life and doesn’t have babies every year. Every two or three years a harpy eagle pair will build a huge nest out of sticks in the top of the tallest tree they can find. The female lays two eggs, which the parents care for together. The female spends most of her time incubating the eggs while the male brings her food, although he will also take a turn incubating while she goes out to stretch her wings and do a bit of hunting herself. When the first egg hatches, the parents bring the baby lots of food and give it lots of attention–but they ignore the other egg at that point, which usually doesn’t hatch as a result. A harpy eagle chick is all white at first, and although it can fly at around 6 months old, its parents will keep feeding it for almost another year.

The harpy eagle is increasingly threatened due to habitat loss and poaching. Because it’s such a big bird, many people shoot it because they think it’s dangerous to livestock or children. But it mostly eats monkeys, sloths, kinkajous and coatis, iguanas, and other medium-sized animals. It’s rare that it attacks livestock since it mostly hunts within the tree canopy for arboreal animals. If your lambs and chickens are sitting on tree branches, you already have a bigger problem than harpy eagles eating them.

A captive breeding program has been started in various zoos around the world, while conservationists work to protect the harpy eagle’s natural habitat so that individuals can be released back into the wild.

We don’t actually know all that much about the harpy eagle, but we know even less about its close relation, the New Guinea harpy eagle. It resembles the harpy eagle but instead of being mostly gray and white, it’s mostly brown and cream in color. It has longer legs and tail but is smaller overall than the harpy eagle, with a wingspan closer to 5 feet across, or 1.5 meters. It has a smaller crest than the harpy eagle too.

Like its South American cousin, the New Guinea harpy eagle hunts in forests, especially rainforests, and spends most of its time perched in a tree, watching for small animals to happen by. Sometimes it will shake a branch to startle any animals in the area to run or fly away, at which point the eagle flies after them. It will even climb around in a tree and poke around in any potential hiding places it finds. It eats tree kangaroos, possums, and other small to medium-sized mammals, but it also eats a lot of birds and reptiles.

While it’s closely related to the harpy eagle, the New Guinea harpy eagle is placed in a different genus. This is also the case for another closely related bird, the crested eagle, which lives in parts of South America. It’s a little smaller than the harpy eagle of South America, with a wingspan of not quite 6 feet across, or 1.8 meters, with a black mask marking over its eyes and a black spot on its crest. Other than that it’s mostly gray.

The two species look enough alike that sometimes people confuse the crested eagle for a young harpy eagle where their ranges overlap. But in at least one documented case, the birds seemingly got confused too.

In early 2004, a team of scientists observing a harpy eagle nest noticed something odd. The nest had one baby in it that was about a month old when the scientists first observed it, and they noticed a crested eagle perched nearby. Every time the scientists visited the nest, the crested eagle seemed to be nearby, although the harpy eagle parents were also around and seemed just fine. The scientists observed the crested eagle adding branches to the nest and even bringing food to the harpy eagle baby. This continued for almost a year. The baby actively solicited food from the crested eagle and happily ate what it brought. At the same time, the harpy eagle parents allowed the crested eagle to approach, although generally the crested eagle didn’t come very close when the harpy eagle parents were around.

The scientists published a short paper about these observations in 2006, including a few hypotheses about the crested eagle’s behavior. They suggested that the crested eagle might have lost her own chick and transferred her maternal instincts to another eagle chick nearby, or she might have just been responding to the eagle chick’s requests for food. She might even have wanted to use that tree for her own nest, but when the bigger, stronger harpy eagles moved in, she abandoned her nest but hung around. A male crested eagle wasn’t observed, so it’s also possible she had lost her mate.

Sometimes different species of raptor do feed each other’s nestlings, although we don’t know why. It also occasionally happens with other types of birds, often male birds whose own nests are still being incubated by the female or by birds whose nest is very close to another nest with babies in it.

Another raptor that hunts animals that live in trees is the crane hawk, also from South America. It lives in forests that are near water and usually hunts by sitting in a tree and watching for potential prey. A lot of the time, though, it hunts like the New Guinea harpy eagle, climbing around in a tree and poking through any nooks and crannies to find animals that are hiding. In the case of the crane hawk, though, it actually has double-jointed legs that allow it to reach a foot into a little hole in a tree to grab prey. Most birds don’t have legs that are flexible enough to allow this behavior. The crane hawk eats a lot of nestling birds, bats, frogs, and other small animals that hide in tree cavities, including some larger invertebrates like cicadas and snails. The only other raptor known to both hunt like this and have double-jointed legs is a genus of African harrier-hawks that aren’t related to the crane hawk. Yes, it’s convergent evolution, at it again!

Let’s get out of the trees now and finish with another raptor Eva suggested. We talked about Ruppell’s griffon vulture in episode 159, but only very briefly.

Ruppell’s griffon vulture is a critically endangered vulture that lives in parts of central and eastern Africa. Unlike the raptors we’ve talked about so far in this episode, it spends a lot of its time soaring at high elevations, so it has really big wings. Its wingspan is as much as 8 and a half feet across, or 2.6 meters. It’s mostly brown and black and like other vultures, it doesn’t have feathers on its head, just a little bit of thin fluff. It will travel enormous distances to find the dead animals it eats, sometimes following herds of migrating animals to scavenge individuals that die of injury or illness. It doesn’t just eat the yummy soft parts of a carcass, it will also eat bones and even the hide of a dead animal. It has a long neck that helps it get to the best bits of its food, uh, from the inside of the carcass. It sometimes even climbs completely inside the rib cage of a dead animal to more easily get every scrap of food.

The way vultures eat is gross, which makes it fun for me to talk about, but vultures are incredibly important. They actually help stop the spread of diseases like rabies and anthrax by eating animals that died of the diseases. The vulture’s digestive tract is so effective that it kills off any viruses that caused the animals to die.

Ruppell’s vulture mates for life. It nests in cliffs, with hundreds of vulture pairs nesting very close together. The female lays one egg, and both parents take care of the baby when it hatches. Even after it can fly, the parents take care of their chick for almost a year while it learns how to find food on its own. Most vultures have relatively weak feet since they don’t use them to catch prey like other raptors, but Ruppell’s vulture has strong feet to help it perch on the cliffs where it nests.

Ruppell’s griffon vulture is one of the highest-flying birds known. It’s been recorded flying as high as 37,000 feet, or 11,300 meters, and we know it was flying at 37,000 feet because unfortunately it was sucked into a jet engine and killed. There’s so little oxygen at that height that a human would pass out pretty much instantly, but the vulture’s blood contains a variant type of hemoglobin that’s more efficient at carrying oxygen than ordinary hemoglobin.

As if all that weren’t enough for one bird, Ruppell’s vulture can also live to be 50 years old. That’s pretty good for an animal that mostly eats rotting and diseased meat.

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