Episode 283: Crocodylomorphs and Friends



Thanks to Max and Pranav for their suggestions this week! We’re going to learn about some crocodylomorphs and a few other ancient non-dinosaur reptiles.

Further reading:

Mammal-like crocodile fossil found in East Africa, scientists report

Ancient crocodiles walked on two legs like dinosaurs

Fossil Footprints Help Uncover the Mysteries of Bipedal Crocodiles

Fossil mystery solved: super-long-necked reptiles lived in the ocean, not on land

Kaprosuchus had TEETH:

Anatosuchus earned its name “duck crocodile”:

Ancient bipedal croc footprints (picture taken from link above):

Tanystropheus had a super long neck:

Show transcript:

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

This week we’re going back in time to learn about some prehistoric reptiles that aren’t dinosaurs. Most are crocodylomorphs, which Pranav suggested a while back, but not all. Thanks to Pranav and Max for their suggestions this week! Max even made some clay models of two of these animals and sent me pictures, which was amazing! I have some really talented listeners.

Pranav and Max both wanted to know about kaprosuchus, also called the boar crocodile. The boar croc lived around 95 million years ago and probably grew nearly 20 feet long, or 6 meters, although all we know about it right now comes from a single nearly complete fossilized skull. The skull was found in Niger, a country in West Africa, and only described in 2009.

The boar croc gets its name from its teeth. It had lots of teeth, because it was a crocodyliform, although not actually an ancestral crocodile. It was related to modern crocs, though. Three sets of its teeth were especially long and large and projected out of its mouth much farther than ever found in any croc or croc relative, with one pair of teeth so big the upper jaw had little grooves for them to fit into so it could actually close its mouth. The teeth look like boar tusks, especially warthog tusks.

The boar croc also had some other differences from other croc relatives. The tip of its snout is unusually heavy, and some researchers think it might have had a keratin sheath over it. It might have used its heavy snout as a battering ram, possibly to stun prey before grabbing it with its huge teeth. It most likely hunted on land instead of in the water, since its eyes were lower on its head than crocs that hunt in water. Modern crocodiles and their relations mostly have eyes at the top of the head, which allows them to stay submerged except for their eyes. Whether it hunted in water or on land, though, the boar croc definitely killed and ate small dinosaurs, or maybe not so small dinosaurs.

The boar croc also had some horn-like projections on the back of its head. I don’t want to alarm you, because this animal went extinct millions and millions of years ago, but this thing was basically a dragon.

Anatosuchus was another crocodylomorph whose fossils have been found in Niger, but it’s much smaller and weirder than you’d expect. It was a tiny little thing, estimated to grow only a little more than 2 feet long, or 70 cm, and it was lightly built with relatively long legs for a croc relation, although it was still smaller than a cat. Its small teeth curve backwards but its snout has a little pointy projection at the front, although its head is broad and flat so that from above, its snout looks kind of like a duck’s bill. That’s why it’s sometimes called the duck crocodile. It lived around 145 million to 100 million years ago. Researchers think it may have waded in shallow water to catch small animals like fish and frogs, something like a heron.

Around 105 million years ago, another small croc relation lived in what is now Tanzania in East Africa. It was first discovered in 2008 and has been named Pakasuchus, which means cat crocodile. It was even smaller than the duck crocodile, only 20 inches long, or 50 cm, with long legs and a delicate build. The really weird thing, though, is its teeth. Unlike other crocodile relations and in fact unlike reptiles in general, it had teeth that were specialized for different functions. Its teeth looked like they belonged to a mammal. It had sharp teeth at the front of its short jaws and broader teeth in the back of its mouth that it used to chew its food. It was a terrestrial animal that would have been active and fast-moving. It probably ate insects and other small animals, but some researchers think it may have eaten plants.

There were definitely some croc relatives that were herbivorous, like the aetosaurs. Aetosaurs lived a little over 200 million years ago and were a successful group, with fossils found in Europe, India, Africa, and North and South America. They had osteoderms that are really common in the fossil record, so common that they’re used as index fossils to date fossil sites. If you’re not sure how old a layer of rock is, and you find some aetosaur osteoderms, you can be pretty certain you’re looking at the late Triassic. The osteoderms are flattened like big scales, and in fact when they were first discovered, people thought they were actually fish scales. Aetosaurs were probably terrestrial animals and most were either herbivorous or omnivorous, although at least one known species had the kind of teeth that indicate it hunted small animals.

A typical aetosaur had a small head and a bulky body with relatively small front legs but stronger hind legs. Its tail was long and tapering like a modern crocodile’s tail. It had lots of armor in the form of interlocking osteoderms, including armor on its belly and the underside of its tail. It might have looked like it had a carapace something like a weird reptilian armadillo. Depending on its species, our typical aetosaur may have also had spikes or spines on its back sort of like modern crocodiles have.

One species of aetosaur, Desmatosuchus spurensis, had massive shoulder spikes. Desmatosuchus grew almost 15 feet long, or 4.5 meters, and was heavily armored, with a spike on each shoulder blade. The spikes curved up and out kind of like a bull’s horns, but instead of pointing forward, they pointed backwards. It also had smaller spikes down its sides, some of which pointed out, some up. The big shoulder spikes could be almost a foot long, or 28 cm.

If you look at Desmatosuchus’s skeleton, it looked like it must have been a dangerous animal, and this would have been true when it comes to worms and plants. Its head was small and ended in a shovel-like snout, probably covered in a keratin sheath like a turtle’s beak. Scientists think it probably used its snout to dig plants up from soft mud along waterways, and it would probably also eat any small animals it found in the mud too. It lived in groups and despite its size and all its spikes, it got eaten a lot by an even bigger reptile, Postosuchus.

Postosuchus wasn’t a dinosaur, and was in fact a crocodylomorph just like the other reptiles we’ve talked about so far, but it sure looked like a dinosaur in a lot of ways. Its front legs were about half the length of and not very strong compared to its hind legs, so it probably walked on its hind legs only. It also had an oversized claw on one of its toes that it probably used to slash at prey, while its big head had a mouth full of big, sharp teeth. In other words, it looked a lot like a theropod dinosaur and lived at about the same time as the first theropods.

Despite not being a dinosaur, Postosuchus was one of the biggest land animals around, growing up to about 23 feet long, or 7 meters, although it probably only stood about 4 feet high, or 1.2 meters. Its remains have only been found in North America.

Other bipedal croc relations have been found in Asia, though, specifically in South Korea where almost 100 beautifully preserved footprints have been found. The tracks are of hind feet only, and from their size, depth, and the length of stride, the animals were probably almost 10 feet long, or 3 meters, and had hind legs the length of an average adult human’s legs. The footprints are almost 9 ½ inches long, or 24 cm.

At first researchers thought the tracks belonged to giant pterosaurs, which were flying reptiles, and that the pterosaurs were walking on their hind legs so their wings would stay out of the mud. But the footprints are so well preserved that it was obvious they belonged to a crocodylomorph once paleontologists examined them closely. In fact, all footprints supposed to belong to pterosaurs walking on their hind legs have turned out to belong to bipedal croc relations. Pterosaurs had to use their wings as front legs when walking on the ground, like bats do but not like birds, and some crocs, which ordinarily walk on four legs, were walking on two. It’s topsy-turvy land!

The tracks in South Korea are dated to a little over 113 million years ago, which is something like 100 million years more recent than Postosuchus. Postosuchus went extinct around 201 million years ago, at the end of the Triassic. By the time the Korean croc relation was walking around, it was the middle of the Cretaceous and dinosaurs ruled the earth. Gondwana was breaking up, the climate was warm worldwide and sea levels were high, mammals were tiny and unimportant, and little birds were flying around along with gigantic pterosaurs like Quetzalcoatlus. Crocodile relations lived in the mid-Cretaceous, sure, but not bipedal ones…or so paleontologists thought.

All we have of these croc relations are their tracks. We don’t have any fossils so we don’t know what they looked like. Hopefully one day some fossils will come to light and paleontologists will be able to match them up with their footprints.

Max specifically asked about Titanoboa, a gigantic extinct snake that lived around 58 million years ago in what is now northern South America. We talked about Titanoboa in episode 197 but I was certain I could find some new information for this episode. Unfortunately, there haven’t been any new studies about Titanoboa published recently, so Max, I’m going to keep it on the suggestions list until I find some interesting new information to share.

Titanoboa is estimated to have grown as much as 42 feet long, or 13 meters, and it probably spent most of its time in the water, eating giant lungfish and other animals. But, to wrap things back around to crocodylomorphs, it probably also ate a croc relation called Cerrejonisuchus. Cerrejonisuchus had a short, narrow snout and probably ate lots of frogs, fish, and other small animals. It grew a little over 7 feet long, or 2.2 meters, which is small but respectable for a crocodile but nowhere near big enough to make Titanoboa think twice about eating it. It wasn’t even the biggest croc relation living in its river habitat. Acherontisuchus grew to an estimated 21 feet long, or almost 6.5 meters. It had a long snout and lots and lots of big teeth, and probably ate the same fish that Titanoboa also liked.

Let’s finish with a non-crocodylomorph ancient reptile, Tanystropheus, and two mysteries associated with it that science solved in 2020. Tanystropheus lived during the mid to late Triassic, around 240 million years ago, and its fossils have been found in parts of Europe, the Middle East, and in China. It grew up to 20 feet long, or 6 meters, but literally half its length was its incredibly long neck.

When the first Tanystropheus fossils were discovered in the 19th century, paleontologists didn’t know what it was. There were some long, thin bones associated with the skeleton and they thought those might be elongated finger bones. Tanystropheus was classified as a type of pterosaur. But as more and better fossils were discovered, it was obvious that this animal wasn’t flying anywhere. The finger bones were actually cervical ribs, rod-like structures that helped stabilize the long neck and keep it from bending very far.

Tanystropheus was reclassified as a long-necked reptile, but no one was sure if it lived in water or just around water. Even more confusing, fossils of smaller long-necked reptiles, only about 4 feet long, or 1.2 meters, started being found too. No one was sure if this was a different species or juvenile Tanystropheus specimens.

To solve the first mystery, a research team took CT scans of some complete but crushed Tanystropheus skulls and generated a 3D image, which allowed them to put the pieces together and examine an image of a complete, un-crushed skull.

The skull had nostrils at the top of its snout, indicating that it probably spent a lot of time in the water. Some researchers suggest it was an ambush predator in shallow water, resting on the bottom of the ocean with its long neck raised so its nostrils were just above the surface. When a fish or other animal swam by, it could grab it without needing to move more than its head. Since its body was chonky with short legs, it probably wasn’t a very fast mover.

Next, the team took cross sections of bones from the smaller long-necked reptile and examined them for growth rings. They found a lot of them, indicating that the animals weren’t juvenile Tanystropheus hydroides, they were adults of another species, which has been named Tanystropheus longobardicus. The two species also had differently shaped teeth, which suggests that they were eating different types of food.

Even though Tanystropheus’s neck was really long, it was also much lighter than the rear half of its body, which had strongly muscled hind legs. Some researchers think it swam by kicking its hind legs sort of like a gigantic frog’s. We have some fossilized trackways from a shallow marine environment that show paired prints from hind legs, but no front leg prints, which may be from a small species of Tanystropheus.

There’s still a lot we don’t know about Tanystropheus, just as there’s a lot we don’t know about a lot of long-extinct animals. All we know for sure is that they were awesome.

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. There are links in the show notes to join our mailing list and to our merch store.

Thanks for listening!


Episode 282: Little Longtailed Birds



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Thanks to Elaine for suggesting one of our long-tailed birds this week!

Happy birthday to Jasper!! Have a great birthday!

Further reading:

Fossil of Ancient Long-Tailed Bird Found in China

All adult scissor-tailed flycatchers have long tails:

The long-tailed sylph male is the one with the long tail:

The long-tailed widowbird male has a long tail:

The long-tailed widowbird female has a short tail:

The pin-tailed whydah male has a long tail:

A pin-tailed whydah baby (left) next to a common waxbill baby (right):

Kompsornis longicaudus had a really long tail:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. This week is a short episode all about little birds with really long tails. The tails are longer than the episode. Thanks to Elaine for suggesting one of the birds we talk about today!

But before we start learning about birds, we have a birthday shout-out! Happy birthday to Jasper, who has the best name and who will hopefully have the best birthday to go along with it!

Let’s start with Elaine’s suggestion, the scissor-tailed flycatcher. I’m embarrassed to admit that Elaine suggested this bird way back in 2020, so it’s about time we talked about it.

The scissor-tailed flycatcher lives in south-central North America during the summer, especially Texas and Oklahoma, and migrates to parts of Mexico and Central America in winter. It’s pale gray with black and white wings and tail, and salmon pink markings on its sides and under its wings. It also has a really long tail. It gets the name scissor-tail because its tail is so long and forked that it’s sort of the shape of an open pair of scissors. The male’s tail is typically longer than the female’s, longer than the rest of its body. The bird is about the size of an average songbird, with a body length of about 5 inches, or 13 centimeters, but with a tail that can increase its overall length to over 14 inches, or 36 cm.

The scissor-tailed flycatcher prefers open areas like pastures and fields, where there’s lots of space but some brush, trees, or fences nearby to perch in. It mostly eats insects, but it will also eat berries, especially in winter. It’s related to kingbirds and pewees and will even hybridize with the western kingbird where their ranges overlap. Its long tail is partly for display, but mostly it helps the bird maneuver in midair as it chases insects, or hover in midair as it looks around for an insect to catch. It especially likes grasshoppers, and when it catches one, it will usually kill it before eating it by smashing it against a tree limb or other perch.

Another little bird with a long tail is the long-tailed sylph, which is a type of hummingbird! It lives on the eastern slopes of the Andes Mountains in northwestern South America, mostly along forest edges, in gardens, grasslands, and other mostly open areas. It migrates to different parts of the mountains at different times of year to follow the flowering of its favorite plants. It’s larger than many species of hummingbird even if you don’t count the tail.

It eats nectar like other hummingbirds do, but also eats tiny insects and spiders. Its bill is black and not very long compared to most of its relations. Sometimes it will jab the tip of its bill straight through the base of a flower to get at the nectar, instead of inserting it into the flower like other hummingbirds do, and while it can hover, sometimes it perches to feed instead.

Both the male and female long-tailed sylph are a beautiful metallic blue and green in color, although the male is brighter and has purplish-brown wings. The female is about 4 inches long, or 10 cm, including her tail, and while the male is about the same size as the female, his tail is really long—up to 4.5 inches long, or 12 cm. His tail is forked like the scissor-tailed flycatcher’s, but unlike the flycatcher, the sylph’s tail makes it harder for the bird to fly. During breeding season the male attracts a mate by flying in a U-shaped pattern that shows off his tail and his flying ability.

The male long-tailed widowbird also attracts a mate with a flying display to show off his long tail. It lives in grasslands in a few parts of Africa, with the biggest population in South Africa. It forages in small flocks looking for seeds, and it also eats the occasional insect or spider. It’s a sparrow-like bird only about 4 inches long, or 10 cm, not counting its tail. The female is mostly brown with darker streaks and has a short tail. The male is black with red and white patches on the shoulders of his wings, called epaulets. His coloring, including the epaulets, is almost identical to that of a totally unrelated bird, the red-winged blackbird of North America, but he has something the blackbird doesn’t: a gigantically long tail.

The male widowbird’s tail is made up of twelve feathers, and about half of them grow up to 20 inches long. That’s nearly two feet long, or half a meter. Like the long-tailed sylph, the long-tailed widowbird’s tail actually makes it harder for him to fly. If it’s raining, he can’t fly at all. Fortunately for him, outside of the breeding season his tail is much shorter. During display flights, he spreads his tail feathers to show them off better and flies very slowly. Males with the longest tails attract the most females.

Similarly, the pin-tailed whydah is another little sparrow-like bird where the male grows a really long tail to attract females. It lives in grasslands, savannas, and open woodlands in sub-Saharan Africa, which just means south of the Sahara Desert. It mostly eats seeds.

During breeding season, the male is a striking pattern of black and white with a bright orangey-red bill and really long tail plumes. He’s about the size of the long-tailed widowbird but his tail grows about 8 inches long, or 20 cm. The female is brown with darker streaks and looks a lot like a sparrow, although it’s not related to sparrows. To impress a female, the pin-tailed whydah will hover in place near her, showing off his long tail plumes and his flying ability.

A lot of whydah species grow long tails. A lot of whydahs are also brood parasites, including this one, meaning that instead of building a nest and taking care of her own eggs, the female sneaks in and lays her eggs in the nest of a different species of bird. Then she flies away, probably whistling to make her seem extra nonchalant, and leaves the other bird to take care of her eggs and the babies when they hatch. She mostly lays her eggs in the nests of various species of finch, and not only do her eggs resemble the finch’s eggs except that they’re bigger, the babies resemble finch babies when they hatch, except they’re bigger.

Specifically, the babies have a really specific gape pattern. When an adult bird approaches its nest, a baby bird will gape its mouth wide to beg for food. This prompts the parent bird to shove some food down into that mouth. The more likely a baby is to be noticed by its parent, the more likely it is to get extra food, so natural selection favors babies with striking patterns and bright colors inside their mouths. Many finches, especially ones called waxbills, have a specific pattern of black and white dots in their mouths that pretty much acts as a food runway. Insert food here. The whydah’s mouth gape pattern mimics the waxbill’s almost exactly. But as I said, the whydah chick is bigger, which means it can push the finch babies out of the way and end up with more food.

The pin-tailed whydah is a common bird and easily tamed, so people sometimes keep it as a pet. This is a problem when it’s brought to places where it isn’t a native bird, because it sometimes escapes or is set free by its owners. If enough of the birds are released in one area, they can become invasive species. This has happened with the pin-tailed whydah in many parts of the world, including parts of Portugal, Singapore, Puerto Rico, and most recently southern California. Since they’re brood parasites, they can negatively impact a lot of other bird species in a very short time. But a study released in 2020 about the California population found that they mostly parasitize the nests of a bird called the scaly-breasted munia, a species of waxbill from southern Asia that’s been introduced to other places, including southern California, where it’s also an invasive species. So I guess it could be worse.

There are lots of other birds with long tails we could talk about, way too many to fit into one episode, but let’s finish with an extinct bird, since that seems to be the theme lately. In May 2020, an ancient bird was described as Kompsornis longicaudus, and it lived 120 million years ago in what is now China. Its name means long-tailed elegant bird. It was bigger than the other birds we’ve talked about today, a little over two feet long, or 70 cm, but a lot of that length was tail.

Kompsornis is only known from a single fossil, but that fossil is amazing. Not only is it almost a complete skeleton, it’s articulated, meaning it was preserved with all the body parts together as they were in life, instead of the bones being jumbled up. That means we know a lot about it, including the fact that unlike other birds of the time, it didn’t appear to have any teeth. It also shows other features seen in modern birds but not always found in ancient birds, including a pronounced keel, which is where wing muscles attach. That indicates it was probably a strong flier. It also had a really long tail, but unlike modern birds its tail was bony like a lizard’s tail although it was covered with feathers.

During their study of Kompsornis, the research team compared it to other birds in the order Jeholornithiformes, which seem to be its closest relations. There were six species known, with Kompsornis making a seventh—except that during the study, the team discovered that one species was a fake! Dalianraptor was also only known from one fossil, and that fossil was of a different bird with the arms of a flightless theropod added in place of its missing wings. Send that fossil to fossil jail!

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 that way.

Thanks for listening!


Episode 281: The Humpback Whale



Thanks to Clay for suggesting the topic of this week’s episode, the humpback whale!

Happy birthday to Emry!

Further reading:

How humpback whales catch prey with bubble nets

Study: Humpback whales aren’t learning their songs from one another

Stanford researchers observe unexpected flipper flapping in humpback whales

Ancient baleen whales had a mouthful

The humpback’s long, thin flippers help it maneuver:

Humpbacks are active, jumpy whales:

A humpback whale’s big mouth:

Show transcript:

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

Thanks to Clay for suggesting this week’s topic, the humpback whale!

But first, we have a birthday shout-out! A great big happy birthday to Emry! I hope your birthday is so epic that in the future, when people look up birthday in the dictionary, your name is listed there.

I’m amazed we haven’t talked about the humpback whale before because when I was little, it was my favorite whale until I learned about the narwhal. Sorry, humpback, you’re now my second favorite whale.

The humpback is a baleen whale, specifically a rorqual, which is a group of related baleen whales. I don’t think I’ve mentioned the term rorqual before because I find it really hard to pronounce. Rorquals are long, slender whales with throat pleats that allow them to expand their mouths when they gulp water in. We talked about this in episode 211 about the fin whale, which is another rorqual. I’ll quote from that episode to explain again what the throat pleats are.

A baleen whale eats tiny animals that it filters out of the water through its baleen plates, which are keratin structures in its mouth that take the place of teeth. The baleen is tough but thin and hangs down from the upper jaw. It’s white and looks sort of like a bunch of bristles at the end of a broom. The whale opens its mouth wide while lunging forward or downward, which fills its huge mouth with astounding amounts of water. As water enters the mouth, the skin stretches to hold even more, until the grooves completely flatten out.

After the whale fills its mouth with water, it closes its jaws, pushing its enormous tongue up, and forces all that water out through the baleen. Any tiny animals like krill, copepods, small squid, small fish, and so on, get trapped in the baleen. It can then swallow all that food and open its mouth to do it again. This whole operation, from opening its mouth to swallowing its food, only takes six to ten seconds.

The humpback mostly eats tiny crustaceans called krill, and little fish. Since gulp feeding takes a lot of energy, finding a lot of food in a relatively small space is important to the whale. Many little fish that live in schools will form what are called bait balls when they feel threatened, where the fish swim closer together and keep moving around. Any given individual fish has a good chance of avoiding being eaten when behaving this way. Think about last week’s episode, where the spinner shark swims straight up through a bait ball, biting biting biting. It eats some fish, but most are fine. But a big filter feeder like the humpback can gulp a whole lot of fish at once, so it really likes bait balls.

To help maneuver prey animals into a small area, groups of humpbacks sometimes employ a strategy called bubble-net feeding. The whales will dive below the fish or krill and swim in a ring, blowing bubbles the whole time. The bubbles startle the animals, who move away from them. But since the bubbles are all around them, and the whales swim closer and closer together so that the ring of bubbles shrinks, eventually the fish or krill are all clustered in a small space as though they’re caught in a net. Then the whales open their mouths and gulp in lots of food. This is actually a simplified explanation of how bubble-net feeding works, which requires several different types of bubbles and various actions by the whales to make it work right.

The humpback is closely related to the fin whale and the blue whale. In episode 211 we learned that fin and blue whales sometimes interbreed and produce offspring, and in at least one case a marine biologist identified a whale that appeared to be the hybrid of a blue whale and a humpback.

The humpback grows up to 56 feet long, or 17 meters, with females being a little larger than males on average. It’s mostly black in color, with mottled white or gray markings underneath and on its flippers. Its flippers are long and narrow, which allows it to make sharp turns. It also has tubercles on its jaws and the fronts of its flippers which are probably sensory organs of some kind, since they contain nerves attached to a very thin hair in the middle that’s about an inch long at most, or almost 3 cm.

This is a good time to remind you that even though they look very different from other mammals, all whales are mammals. Mammals are warm-blooded animals that produce milk for their babies. Mammals also have hair, unless they don’t have hair, except that the humpback whale does have hairs in its tubercles. So there you go, humpback whales have hair.

Despite its huge size, the humpback is an active whale. It frequently breaches, meaning it rises up out of the water almost its full length, then crashes back down into the water with a huge splash. It also often slaps its flippers or its tail on the surface. Some researchers think these behaviors may have something to do with communication with other whales, or that the whale is trying to get rid of parasites, or that the whale is just having fun.

Humpback whales are famous for their elaborate songs, which are produced by males. The whales breed in winter, and the males start singing as winter gets closer, so the songs must have something to do with mating season. Scientists aren’t sure what, though. Females don’t seem to be very interested in individual males who are singing, but they will sometimes be attracted to a group of singing males. Some researchers suggest that singing might be a general call to attract all whales in the area to the breeding grounds. Then again, sometimes a male will interrupt another male who is singing and the two will fight.

The songs vary and new song elements can spread quickly through a population. Generally, researchers think males hear a new element and incorporate it into their own songs, but results of a study published in 2021 found that similar new song elements often show up in whales that could not have heard other whales sing it. This indicates that instead of copying other songs, each whale modifies his own song individually and sometimes the changes are similar. That’s just one study, though. It’s probable that the way males change their songs depends on many factors, only one of which is hearing and imitating other songs.

The study suggests that the way we think about whale songs might be wrong to start with. Researchers generally think that a whale probably sings for the same reasons that birds sing: to stake out a territory, to advertise to potential mates that it’s healthy enough to spend energy singing, and to warn rivals away. But because whales live in an environment so different from birds, and so different from what we as humans understand, it’s possible that whalesong carries meanings and intentions that we can’t interpret. A different study published in 2019 discovered that male humpbacks sometimes sing in feeding grounds, especially when a population of whales decides to overwinter at their feeding grounds instead of migrating, as sometimes happens.

What, precisely, a whale’s song means to other whales is something that only the whales know for sure. This is what a humpback song sounds like:

[humpback song]

Humpbacks make other sounds other than songs, though. Mothers and calves need to communicate so that the calves get the care they need and don’t stray too far away, but since any sounds could attract predators, they have to communicate very quietly. They make little grunting sounds to each other.

The main predator of the humpback whale is the orca, which will attack and kill calves and sometimes even adults. As a result, the humpback really does not like orcas. Humpbacks will sometimes protect seals and other animals from orca attacks.

Humpbacks migrate from their summer habitats in either the Antarctic or the Arctic, depending on what hemisphere they live in, to their winter breeding grounds in tropical waters. Then they return to colder waters in summer where there’s more food, since krill is a cold-water species. These migrations can be as long as 5,000 miles, or 8,000 kilometers. Unlike some animals that migrate in huge herds, humpbacks mostly travel in small groups that are often widely spaced.

The humpback was almost driven to extinction by commercial whaling, but after it was declared a protected species, its numbers have increased. It still has the same human-caused dangers that many other marine animals face, including habitat loss and water pollution, climate change, drowning after being entangled in nets, and noise pollution that can keep whales from communicating.

There’s always a lot we don’t know about any given species of whale, since whales are hard to study. For instance, a 2017 study discovered that humpbacks sometimes swim in a way never documented in whales before. Whales swim by flexing their massively powerful tails, and use their flippers to maneuver. Think of the tail as the engine of a car and the flippers as the power steering system. The humpback’s flippers are uniquely shaped, which as we mentioned earlier means it can maneuver skillfully, turning much more quickly than a great big whale would otherwise be able to turn. But in video studies of whales in the wild, very rarely a whale would flap its flippers like a bird flapping its wings—or, more accurately, like a seal or sea lion swimming with its flippers. The researchers who analyzed the videos suggest that the flapping is used for accelerating quickly, and because it takes a lot of energy, the whales don’t do it often. The researchers also think the humpback may be the only whale species that can accelerate using the motion of its flippers, since other whales have much smaller flippers relative to their size.

As far as we know, baleen whales don’t use sonar the way toothed whales do. Their songs and sounds are for communication, not navigation. But while humpbacks mostly hunt for food near the surface of the water where there’s plenty of light, they do occasionally dive deeper and hunt for food near the bottom. They especially like an eel-like fish called the sand lance, which spends a lot of time buried in the sand on the sea floor. In 2014, a study of humpbacks diving to find these fish indicated that when a whale dives alone, it remains silent, but when it dives to hunt with some friends, they communicate with a sound described as a tick-tock. Not the app, just a sound like the ticking of a clock. Sometimes more humpbacks come to join the whales when they hear their tick-tock sounds. But we still don’t know how the whales find the fish in the first place, since there’s no light for them to hunt by. It’s possible they can detect the fish’s chemical signature in the water when they’re close enough to one.

Baleen whales don’t have teeth, although when a baby whale is developing in its mother’s womb it does grow teeth. But at some point during its development, these embryonic teeth are reabsorbed and baleen plates form instead.

The extinct ancestors of modern baleen whales still had teeth. One genus was called Aetiocetus, which lived between about 34 and 23 million years ago in the north Pacific Ocean. It probably wasn’t directly related to modern whales, since baleen whales do actually appear in the fossil record before Aetiocetus. It was a small whale that probably only grew about 11 feet long, or 3.5 meters, although some species might have grown twice that length. The first Aetiocetus fossils were discovered in the 1960s and it was initially described as a toothed whale, since it had teeth.

But not everyone agreed. Aetiocetus showed some adaptations to filter feeding seen in modern baleen whales. For instance, its lower jaw bones weren’t fused at the chin end as they are in toothed whales. Modern baleen whales don’t have connected lower jaw bones, and in fact they have a sensory organ at that spot that scientists think helps the whale keep from engulfing too much water and hurting itself.

Recently, a team of scientists examined a CT image of a skull of Aetiocetus weltoni and discovered something surprising. Baleen is made of keratin, and keratin is only preserved in fossils very rarely, but in baleen whale fossils, the upper jawbones do show grooves where the baleen once connected. These grooves were present in the Aetiocetus skull, even though it also had teeth.

Researchers think Aetiocetus may have used its teeth to filter larger fish from the water the way some animals like crab-eater seals do today. Its teeth interlocked, which would allow it to trap fish in its mouth while pushing water out between its teeth. Its baleen probably helped catch smaller fish and other animals. The baleen was far enough away from the teeth that the whale would have still been able to bite at fish and other prey without accidentally biting its own baleen. But, as the researchers mention in their 2021 paper, Aetiocetus had a really crowded mouth.

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 280: Lesser-Known Sharks



Thanks to Tobey and Janice this week for their suggestions of lesser-known sharks!

Further reading/watching:

CREATURE FEATURE: The Spinner Shark [this site has a great video of spinner sharks spinning up out of the water!]

Acanthorhachis, a new genus of shark from the Carboniferous (Westfalian) of Yorkshire, England

150 Year Old Fossil Mystery Solved [note: it is not actually solved]

The cartoon-eyed spurdog shark:

The spinner shark spinning out of the water:

The spinner shark not spinning (photo by Andy Murch):

A Listracanthus spine:

Show transcript:

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

This week we’re going to learn about three sharks you may have never heard of before! The first was suggested by my aunt Janice and the second by listener Tobey. The third is a mystery from the fossil record.

You may have heard about the findings of a study published in November of 2021, with headlines like “Venomous sharks invade the Thames!” My aunt Janice sent me a link to an article like this. Nobody is invading anything, though. The sharks belong where they are. It was their absence for decades that was a problem, and the study discovered that they’re back.

The Thames is a big river in southern England that empties into the North Sea near London. Because it flows through such a huge city, it’s pretty badly polluted despite attempts in the last few decades to clean it up. It was so polluted by the 1950s, in fact, that it was declared biologically dead. But after a lot of effort by conservationists, fish and other animals have moved back into the river and lots of birds now visit it too. It also doesn’t smell as bad as it used to. One of the fish now found again in the Thames is a small shark called the spurdog, or spiny dogfish.

The spurdog lives in many parts of the world, mostly in shallow water just off the coast, although it’s been found in deep water too. A big female can grow almost three feet long, or 85 cm, while males are smaller. It’s a bottom dweller that eats whatever animals it finds on the sea floor, including crabs, sea cucumbers, and shrimp, and it will also eat jellyfish, squid, and fish when it can catch them. It’s even been known to hunt in packs.

It’s gray-brown in color with little white spots, and it has large eyes that kind of look like the eyes of a cartoon shark. It also has a spine in front of each of its two dorsal fins, which can inject venom into potential predators. The venom isn’t deadly to humans but would definitely hurt, so please don’t try to pet a spurdog shark. If the shark feels threatened, it curls its body around into a sort of shark donut shape, which allows it to jab its spines into whatever is trying to grab it.

The spurdog used to be really common, and was an important food for many people. But so many of them were and are caught to be ground into fertilizer or used in pet food that they’re now considered vulnerable worldwide and critically endangered around Europe, where their numbers have dropped by 95% in the last few decades. It’s now a protected species in many areas.

The female spurdog retains her fertilized eggs in her body like a lot of sharks do. The eggs hatch inside her and the babies develop further before she gives birth to them and they swim off on their own. It takes up to two years before a pup is ready to be born, and females don’t reach maturity until they’re around 16 years old, so it’s going to take a long time for the species to bounce back from nearly being wiped out. Fortunately, the spurdog can live almost 70 years and possibly longer, if it’s not killed and ground up to fertilize someone’s lawn. The sharks like to give birth in shallow water around the mouths of rivers, where the water is well oxygenated and there’s lots of small food for their babies to eat, which is why they’ve moved back into the Thames.

Next, Tobey suggested we talk about the spinner shark. It’s much bigger than the spurdog, sometimes growing as much as 10 feet long, or 3 meters. It lives in warm, shallow coastal water throughout much of the world. It has a pointy snout and is brown-gray with black tips on its tail and fins, and in fact it looks so much like the blacktip shark that it can be hard to tell the two species apart unless you get a really good look. It and the blacktip shark also share a unique feeding strategy that gives the spinner shark its name.

The shark eats a lot of fish, especially small fish that live in schools. When the spinner shark comes across a school of fish, it swims beneath it, then upward quickly through the school. As it swims it spins around and around like an American football, but unlike a football it bites and swallows fish as it goes. It can move so fast that it often shoots right out of the water, still spinning, up to 20 feet, or 6 meters, before falling back into the ocean. The blacktip shark sometimes does this too, but the spinner shark is an expert at this maneuver.

There’s a link in the show notes to a page where you can watch a video of spinner sharks spinning out of the water and flopping back down. It’s amazing and hilarious. Tobey mentioned that the spinner shark is an acrobatic shark, and it certainly is! It’s like a ballet dancer or figure skater, but with a lot more teeth. And fewer legs.

Because spinner sharks mainly eat fish, along with cephalopods, they almost never attack humans because they don’t consider humans to be food. Humans consider the spinner shark food, though, and they’re listed as vulnerable due to overhunting and habitat loss.

We’ll finish with a mystery shark. I’ve had Listracanthus on my ideas list for a couple of years, hoping that new information would come to light, but let’s go ahead and talk about it now. It’s too awesome to wait any longer.

We know very little about Listracanthus even though it was around for at least 75 million years, since it’s an early shark or shark relative with a cartilaginous skeleton. Cartilage doesn’t fossilize very well compared to bone, so we don’t have much of an idea of what the shark looked like. What we do have are spines that grew all over the fish and that probably made it look like it was covered with bristles or even weird feathers. The spines are a type of denticle that could be up to 4 inches long, or 10 cm. They weren’t just spines, though. They were spines that had smaller spines growing from their sides, sort of like a feather has a main shaft with smaller shafts growing from the sides.

The spines are fairly common in the fossil record from parts of North America, dating from about 326 million years ago to about 251 million years ago. Listracanthus was closely related to another spiny shark-like fish, Acanthorhachis, whose spines have been found in parts of Europe and who lived around 310 million years ago, but whose spines are less than 3 inches long at most, or 7 cm.

Some researchers think the spines were only present on parts of the shark, maybe just the head or down the back, but others think the sharks were covered with the spines. Many times, lots and lots of the spines are found together and probably belong to a single individual whose body didn’t fossilize, only its spines. Some researchers even think that the flattened denticles from a shark or shark relation called Petrodus, which is found in the same areas at the same times as Listracanthus, might actually be Listracanthus belly denticles.

The spines probably pointed backwards toward the tail, which would reduce drag as the fish swam, and they might have been for display or for protection from predators, or of course both. The main parts of the spine were also hollow and there’s evidence there were capillaries inside, so they might have had a chemosensory or electrosensory function too.

Modern sharks have denticles that make their skin rough, sort of like sandpaper. One modern shark, the sandy dogfish, Scyliorhinus canicula, which is common in shallow water off the coasts of western Europe and northern Africa, and in the Mediterranean, has especially rough denticles on its tail. They aren’t precisely spines, but they’re more than just little rough patches. The sandy dogfish is a small, slender shark that barely grows more than about three feet long, or about a meter, and it eats anything it can catch. Young dogfish especially like small crustaceans, and sometimes they catch an animal that’s too big to swallow whole. In that case, the shark sticks the animal on the denticles near its tail, which anchors it in place so it can tear bite-sized pieces off. Some other sharks do this too, so it’s possible that Listracanthus and its relations may have used its spines for similar behavior.

We don’t know much about these sharks because all we have are their spines. Only one probable specimen has been found, by a paleontologist named Rainer Zangerl. Dr. Zangerl found the remains of an eel-like shark in Indiana that was covered in spines, but unfortunately as the rock dried out after being uncovered, the fossil literally disintegrated into dust.

In August of 2019, a fossil hunter posted on an online forum for fossil enthusiasts to say he’d found a Listracanthus specimen. He posted pictures, although since the fossil hasn’t been prepared it isn’t much to look at. It’s just an undulating bump down a piece of shale that kind of looks like a dead snake. Fortunately, the man in question, who goes by RCFossils, knew instantly what he’d found. He also knew better than to try to clean it up himself. Instead, he’s been working on trying to find a professional interested in taking the project on. In May of 2022 he posted again to say he’d managed to get an X-ray of the fossil, which shows a backbone but no sign of a skull. He’s having trouble finding anyone who has the time and interest in studying the fossil, but hopefully he’ll find someone soon and we’ll all learn more about this mysterious pointy shark.

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 279: Mean Piggies



Thanks to Molly for suggesting andrewsarchus and entelodont, our mean “piggies” we learn about this week!

Further reading:

Andrewsarchus, “Superb Skull of a Gigantic Beast”

Dark Folklore by Mark Norman and Tracey Norman

Further listening:

The Folklore Podcast

Andrewsarchus (taken from article linked above):

Andrewsarchus’s skull. I’m not sure who the guy holding it is, but I like to think his name is Andrew:

Entelodont:

Show transcript:

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

I’m getting really backed up on listener suggestions, so over the next few months I plan to cover as many of them as possible. We’ll start with two suggestions by Molly, who wanted to learn about Andrewsarchus and the related Entelodont. We talked about entelodonts briefly back in episode 116, and if you remember that episode, you may remember that entelodonts are sometimes referred to as the terminator pig or the hell pig. So yes, we are going to learn about some mean piggies this week, with a bonus fun mystery piggy at the end.

Andrewsarchus mongoliensis lived in what is now central Asia about 42 million years ago. It’s only known from a single skull found in 1923 in Inner Mongolia, which is part of China these days. The skull has a long snout and is big and wide, over 2.5 feet long, or 83 cm. It has huge, strong teeth that look ferocious.

When the skull was first found, some paleontologists on the team thought it was from a huge wolf-like carnivore. But others weren’t so sure. They thought it was the skull of a pig relative, and pigs are omnivores. Without more fossil remains, we can’t know for sure what Andrewsarchus’s body looked like, but these days scientists mostly think it was closely related to entelodonts.

Despite being called the terminator pig, entelodonts weren’t very closely related to pigs, although they and Andrewsarchus are in the order Artiodactyla. That’s the order that includes all even-toed hoofed mammals and their close relations, including pigs, but also including hippos and whales. Hippos and whales are actually pretty closely related, and entelodonts and Andrewsarchus were more closely related to hippos than to pigs.

Daeodon [DIE-oh-don] was the biggest entelodont known, and it may have stood up to 7 feet tall at the shoulder, or just over 2 meters. It lived in North America, but there was another species from Eurasia, Paraentelodon intermedium, that was probably close to the same size. Both lived about 22 million years ago.

Entelodonts had big, wide skulls with flared cheekbones and knob-like bony protrusions, so its head may have looked something like a warthog’s head. It also had cloven hooves. We don’t know if Andrewsarchus had hooves since we haven’t found anything but that one huge skull. The larger species of Entelodont had a humped shoulder something like a bison for the attachment of strong neck muscles to support the head’s weight, and Andrewsarchus probably had this too. The rest of the body was much more lightly built, with short, slender legs and a skinny little tail.

Even though Entelodont teeth are fearsome-looking, and at least some species of Entelodont were probably active hunters, they’re considered omnivores and Andrewsarchus probably was too. In fact, because Andrewsarchus was found on what was once a beach along the ocean, some researchers think it might have used its big forward-pointing front teeth to dig shellfish out of the sand. Most likely it ate pretty much anything it could find or catch, including shellfish, turtles, and other small animals, carrion, and plant material like fruit, nuts, and roots.

The teeth of some entelodont species show wear marks that indicate it probably bit through bones pretty frequently, possibly while scavenging already dead animals but possibly also when killing prey. One fossil skull of a herbivorous artiodactyl that lived in North America was found with an entelodont incisor embedded in it.

On the other hand, we have a set of fossil tracks in Nebraska, in the United States, that shows the behavior of what may have been an entelodont called Archaeotherium. Archaeotherium lived around 30 million years ago and grew up to 5 feet tall at the shoulder, or 1.5 meters, although most specimens found were closer to 4 feet tall, or 1.2 meters. The fossil tracks are from three animals: a type of rhinoceros, a predator of some kind, possibly the hyena-like Hyaenodon, and a species of Archaeotherium. The rhinoceros tracks show that it was walking along, then suddenly took off at a run. The Hyaenodon tracks are nearby and possibly indicate pursuit of the rhino, or it might have just happened to be nearby and frightened the rhino. The Archaeotherium tracks, meanwhile, zigzag back and forth. What on earth is going on with that?

Entelodonts had a very good sense of smell, much like pigs do, and walking in a zigzag pattern would allow Archaeotherium to smell things more efficiently. Some researchers suggest it might have been keeping an eye on the rhino hunt, and that if the Hyaenodon managed to bring down its prey, Archaeotherium might have decided to chase Hyaenodon away from its kill. It might also have been waiting for one or both animals to become tired, and then it could attack. Then again, it might just have been looking for some yummy fruit to eat. While some places online will tell you Archaeotherium was hunting the rhino, that’s not what the tracks indicate.

Entelodonts could open their mouths really, really wide. If you’ve ever seen a hippo with its humongous mouth open, that’s what we’re talking about here. Male hippos sometimes fight by jaw-wrestling each other, and researchers think entelodonts might have done something similar. A lot of entelodont skulls show healed puncture wounds in places consistent with jaw-wrestling. The knobby protrusions on its skull might have been an adaptation to this behavior, with thickened skin over them to keep a rival’s teeth from biting too deeply. This is the case with some pigs with similar skull protrusions, which we talked about in episode 128. The head bite wounds are only seen in adult animals, and younger animals didn’t have the massive cheek and jaw muscles seen in adults.

The big question is whether Andrewsarchus was actually an entelodont or just closely related to the entelodonts. That’s the same thing paleontologists have been discussing for the last century. Until we find more Andrewsarchus fossils, though, there’s only so much we can determine about the animal, including how similar it was to the entelodonts. For instance, while entelodonts did have cloven hooves, the two halves of the hoof could spread apart like fingers, which is similar to the way camel feet are structured. This would have helped it walk on soft ground, like sand or mud. If Andrewsarchus turns out to have similar feet, it was probably an entelodont.

Finding more Andrewsarchus remains will allow us to get a good idea of how big it could grow, too. Estimates based on the same proportions seen in entelodonts suggest it might have stood about 6 feet tall at the shoulder, or 1.8 meters.

As we’ve established, entelodonts and Andrewsarchus weren’t actually pigs, although they probably looked a lot like weird oversized warthogs with some features seen in wild boars. There’s no evidence they had a pig-like snout, called a nasal disk, which is flattened at the end. Entelodonts had nostrils on the sides of the snout, something like a horse’s nostrils.

But let’s finish with an actual pig, the mystery of the sewer pig. I got this information from a fantastic book called Dark Folklore by Mark and Tracey Norman, and I read the book because I listen to The Folklore Podcast, which is by folklorist Mark Norman, although I think Tracey Norman helps out with it too. I’ll just quote from the book, and definitely check the show notes for a link if you want to order your own copy.

“Foreshadowing the 1980s panic about baby alligators being taken home as pets and subsequently flushed down the toilet into the sewer system of New York, 1859 London was overtaken by a panic about the Sewer Pigs of Hampstead.

“The sewer pigs were thought to be a monstrous porcine family living entirely below ground in the London sewer system, and even featured in the Daily Telegraph newspaper. A sow had apparently become trapped, it was said, and had given birth to a litter of piglets, the entire family living off the rubbish that accumulated in the sewers and producing litter after litter. The population lived in fear of these terrible creatures escaping from the sewer system and running riot throughout London.

“Obviously, there is nothing within a sewer system that would sustain a pig, let alone a number of them. The fear connected to this particular urban legend is disease and it arose after the hot summer of 1858 caused a devastating outbreak of typhoid and cholera in the city. Unsurprisingly, there has never been any evidence of pigs in London’s sewers, monstrous, lost or otherwise.”

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 278: Gender Diverse Animals



This week is Connor’s episode, and we’re going to learn about some animals that don’t conform to “typical” gender roles, one way or another.

I’ll be at ConCarolinas this week, from June 3 through 5, including recording a live crossover episode with Arcane Carolinas!

Further reading:

Species of algae with three sexes that all mate in pairs identified in Japanese river

How a microbe chooses among seven sexes

Facultative Parthenogenesis in California Condors

The sparrow with four sexes

Chinstrap penguins make good dads:

Laysan albatrosses make good moms:

Black swans make good dads:

Some rams really like other rams (photo by Henry Holdsworth):

New Mexico whiptail lizards are all females:

California condor females don’t always need a male to produce fertilized eggs:

Clownfish change sex under some circumstances:

The white-throated sparrow essentially has four sexes:

You are awesome (photo by By Eric Rolph)!

Show transcript:

“Hey y’all, this is Connor. Welcome to a very special Pride Month edition of the Strange Animals Podcast.”

This week we have Connor’s episode! We decided to make it the very last episode in our Kickstarter month so that it’s as close to the month of June as possible, because June is Pride Month and our episode is about gender-diverse animals! Don’t worry, parents of very young children, we won’t be discussing mating practices except in very general terms.

Pride month celebrates people’s differences when it comes to gender expression and sexuality. That’s why its symbol is the rainbow, because a rainbow is made up of all different colors the same way there are different kinds of people. Sometimes people get angry when they hear about Pride month because they think there are only two genders, and that those two genders should only behave in certain ways. Pffft. That’s not even true when it comes to animals, and humans are a lot more socially complicated.

For instance, let’s start by talking about a humble creature called algae. If you remember episode 129, about the blurry line between animals and plants, you may remember that algae isn’t actually a plant or an animal. Some species resemble plants more than animals, like kelp, but they’re not actually plants. In July of 2021, scientists in Japan announced that a species of freshwater algae has three sexes: male, female, and bisexual. All three sexes can pair up with any of the others to reproduce and their offspring may be male, female, or bisexual at random.

Even though the algae has been known to science for a long time, no one realized it has three sexes because most of the time, algae reproduces by cloning itself. The research team thinks that a lot of algae species may have three sexes but researchers just haven’t been looking for it.

Yes, I realize that was a weird place to start, but it’s also fascinating! It’s also not even nearly as complicated as a protozoan called Tetrahymena thermophila, which has seven sexes.

Let’s look at a bird next, the penguin. You’ve probably heard of the book And Tango Makes Three, about two male penguins who adopt an egg and raise the baby chick together. For some reason some people get so angry at those penguins! Never trust someone who doesn’t like baby penguins, and never trust someone who thinks animals should act like humans. The events in the book are based on a true story, where two male chinstrap penguins in New York’s Central Park Zoo formed a pair bond and tried to hatch a rock, although they also tried to steal eggs from the other penguins. A zookeeper gave the pair an extra penguin egg to hatch instead.

The most interesting thing about the story is that same-sex couples are common among penguins, in both captivity and in the wild, among both males and females. Since penguins sometimes lay two eggs but most species can only take care of one chick properly, zookeepers often give the extra eggs to same-sex penguin pairs. The adoptive parents are happy to raise a baby together and the baby is more likely to survive and be healthy. Occasionally a same-sex penguin couple will adopt an egg abandoned by its parents.

If you remember episode 263 a few months ago, where we talked about animals that mate for life, you may remember the Laysan albatross. In that episode we learned about a specific Laysan albatross named Wisdom, the oldest wild bird in the world as far as we know. While I was researching Wisdom, I learned something marvelous. As many as 30% of all Laysan albatross pairs are both females. Sometimes one of the females will mate with a male and lay a fertilized egg, and then both females raise the baby as a couple. Sometimes one of the females lays an unfertilized egg that doesn’t hatch. There are many more Laysan albatross females than males, which may be the reason why females form pairs, but it’s perfectly normal behavior. It’s also been a real help to conservationists. Sometimes an albatross pair will nest in an area that’s not safe, like on an airfield. Instead of leaving the egg to be smashed by an airplane, conservationists take the fertilized egg from the unsafe nest and use it to replace the unfertilized egg of a female pair. The egg is safe and the chick has adoptive parents who raise it as their own.

Many other birds develop same-sex pairs too. This is especially common in the black swan, where up to a quarter of pairs are both male. One or both of the males will mate with a female, but after she lays her eggs the males take care of them and the cygnets after they hatch. Cygnets raised by two dads are much more likely to survive than cygnets raised by one mom and one dad. The males are stronger and more aggressive, so they can defend the nest and babies more effectively.

Birds aren’t the only animals that form same-sex pair bonds. Many mammals do too. It’s been documented in the wild in lions, elephants, gorillas, bonobos, dolphins, and many more. In species that don’t typically form pair bonds, homosexual behavior is still pretty common. It’s so common among domestic sheep that shepherds have to take into account the fact that up to 10% of rams prefer to mate with other rams instead of with ewes. Some rams show attraction to both males and females. This happens in wild sheep too, where rams may court other rams the same way they court ewes. Some ewes also show homosexual behavior.

The New Mexico whiptail is a lizard that lives in parts of the southwestern United States and northern Mexico. It can grow over nine inches long, or 23 cm, and is black or brown with yellow racing stripes. It eats insects and is an active, slender lizard that’s common throughout its range. And every single New Mexico whiptail lizard is a female.

The lizards reproduce by a process called parthenogenesis. That basically means an animal reproduces asexually without needing to have its eggs fertilized. The lizards do mate, though, but not with males. Females practice mating behaviors with each other, which researchers think causes a hormone change that allows eggs to develop. Females who don’t mate don’t develop eggs.

Female birds can sometimes reproduce asexually too. It’s been documented in turkeys, chickens, pigeons, finches, and even condors. A study published in late 2021 detailed two instances of parthenogenesis in California condors in a captive breeding program. In both cases the females were housed with their male mates, and in both cases the pairs had produced offspring together before. But in both cases, for some reason the females laid eggs that hatched into chicks that were genetically identical to the mothers. It’s possible parthenogenesis is even more common in birds than researchers thought.

In many species of reptile, whether a baby is a male or female depends completely on how warm its egg gets during incubation. For example, the American alligator. The mother gator builds a nest of plant material and lays her eggs in it. As the plant material decays, it releases heat that keeps the eggs warm. How much heat is generated depends on where the mother alligator builds her nest and what plants she uses, which in turns affects the eggs. If the temperature in the nest is under 86 degrees Fahrenheit, or 30 Celsius, during the first few weeks of incubation, most or all of the eggs will hatch into females. If the temperature is 93 F or 34 C, most or all of the eggs will hatch into males. If the temperature is between the two extremes, there will be a mix of males and females, although usually more females.

Because climate change has caused an overall increase in temperatures across the world, some already vulnerable reptile populations, especially sea turtles, are hatching almost all males. Conservationists have to dig up the eggs and incubate them at a cooler temperature in captivity, then release the babies into the ocean when they hatch.

Other animals change from male to female or vice versa, depending on circumstances. The clownfish, for example. Clownfish start out life as males but as they grow up, most become females, although only the dominant pair in a colony actually reproduces. Clownfish live in colonies led by the largest, most aggressive female, with the largest, most aggressive male in the group as her mate. If something happens to her, her former mate takes her place, becoming a female in the process. The largest juvenile male then becomes her mate and remains male even though he puts on a growth spurt to mature quickly. If Finding Nemo was scientifically accurate, it would have been a much different movie.

Another group of fish that live around reefs are wrasses, which includes the famous cleaner fish that cleans parasites and dead tissue off of larger fish. Wrasses hatch into both males and females, but the males aren’t the same type of males that can breed. Those develop later. When the dominant breeding male of the group dies, the largest female or the largest non-breeding male then develops into a breeding male. But sometimes a non-breeding male will develop into a female instead.

The term for an animal that changes sex as part of its natural growth process is sequential hermaphroditism. It’s common in fish and crustaceans in particular. Other animals have the reproductive organs of both a male and a female, especially many species of snail, slug, earthworm, sea slug, and some fish. We talked about the mangrove killifish in episode 133, and in that episode I said it was the only known vertebrate hermaphrodite. That’s actually not accurate, although I was close. It’s the only known vertebrate hermaphrodite that can self-fertilize. Almost all mangrove killifish are females, although they also produce sperm to fertilize their own eggs. The eggs hatch into little clones of the mother.

We’ve talked about seahorses before too, especially in episode 130. Seahorse pairs form bonds that last throughout the breeding season. The pair participate in courtship dances and spend most of their time together. When the eggs are ready, the female deposits them in a special brood pouch in the male’s belly, where he fertilizes them. They then embed themselves in the spongy wall of the brood pouch and are nourished not only by the yolk sacs in the eggs, but by the male, who secretes nutrients in the brood pouch. So basically the male is pregnant. The female visits him every day to check on him, usually in the mornings. When the eggs hatch after a few weeks, the male expels the babies from his pouch and they swim away, because when they hatch they are perfectly formed teeny-tiny miniature seahorses.

Let’s finish with a little songbird that’s common throughout eastern North America, the white-throated sparrow. It has a white patch on its throat and a bright yellow spot between the eye and the bill. There are two color morphs, one with black and white stripes on its head, one with brown and tan stripes on its head. Both males and females have these head stripes. The male sings a pretty song that sounds like this:

[white-throated sparrow call]

A 30-year study into white-throated sparrow genetics has revealed some amazing things. The color morphs are due to a genetic difference that affects a lot more than just feather colors. Black morph males are better singers, but they don’t guard their territory as well or take care of their babies as well as brown morphs do. They also aren’t as faithful to their mates as the brown morph males, which are fully monogamous and are diligent about helping take care of their babies. Despite their differences in raising offspring, both morphs are equally successful and equally common.

All this seems to be no big deal on the surface, maybe just pointing to the possibility that the species is in the process of splitting into two species or subspecies. But that’s not the case.

Black morphs always mate with brown morphs. A black morph male will always have a brown morph mate, and vice versa. Genetically, the two morphs are incredibly different—so different, in fact, that they seem to be developing a fully different set of sex chromosomes. In other words, there are male and female black morph birds and male and female brown morph birds that are totally different genetically, but still members of the same species that only ever breed with each other. In essence, the white-throated sparrow has four sexes.

Usually I try to end episodes with something funny, but today I’m going to speak directly to you. Yes, you! If you’re listening to this or reading the transcript, my words are meant just for you. You are an amazing person and I love you. You deserve to be happy. If anyone has ever told you there’s something wrong with the way you are, or the way you wish you were or want to be, they’re wrong. They probably also don’t like penguins, so you don’t have to believe anything they say. If you’ve ever read books by Terry Pratchett, you may recognize this quote: “Be yourself, as hard as you can.”

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 277: Rewilding Scotland



This week is Caitie Sith and Dave’s episode! They want to learn about animals reintroduced to Scotland, especially the Highland wildcat!

The Scottish (or Highland) wildcat:

The Eurasian lynx:

The Eurasian beaver (with babies!):

The white-tailed eagle:

Reindeer in Scotland:

The pine marten:

Show transcript:

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

This week is Caitie Sith and Dave’s episode, where we’ll learn about the re-wilding of Scotland! Re-wilding is the process of restoring an ecosystem to its natural state, basically reversing habitat loss. Most of the time there’s a lot more to it than just reintroducing native animals, but sometimes that’s all that’s required.

Scotland is a part of the island of Great Britain, north of England. People have lived there since the last glaciers melted at the end of the Pleistocene, around 12,000 years ago. During the Pleistocene and a few thousand years after the glaciers melted, Scotland was connected to Europe by a lot of marshy land where today there’s ocean, and naturally many animals lived in Scotland that were also found in Europe at the time. Some of the ice age megafauna that lived in Scotland included the woolly rhinoceros, woolly mammoth, bison, aurochs, wild boar, saiga antelope, giant deer, red deer, reindeer, moose, wild horse, beaver, walrus, Polar bear, brown bear, lynx, wolf, Arctic fox, and cave lion. Many fossil and subfossil remains of Pleistocene animals were destroyed by the formation and movement of thick glacier ice, which scoured the land down to bedrock in many places, so those are only the animals we know for sure lived in Scotland.

But Scotland wasn’t covered by glaciers all the time. The Pleistocene wasn’t a single ice age but a series of cold events interspersed with warming trends. During these interglacial periods, which lasted some 10- to 15,000 years at a time, animals would move to Scotland from other places or become more numerous than before. Then the climate would start cooling again, glaciers would slowly form over many years, and animals would move to areas where there was more food. This happened repeatedly over a period of more than 2.5 million years.

In other words, while we have some fossils of Pleistocene animals that once lived in Scotland, we don’t have nearly as many as have been found in England, Ireland, and Wales. But what we do know is that Scotland was once teeming with all kinds of animals we’d never associate with the country today, like cave lions and Polar bears!

Much of the ice age megafauna went extinct around 12,000 years ago when the last glaciers melted and the climate started warming. Cold-adapted animals couldn’t always survive in a warmer climate, not to mention that as the climate changed, the types of plants available to eat changed too. Some animals migrated away or went extinct, while some were able to stay in Scotland successfully. This included the red deer, reindeer, wild boar, walrus, brown bear, and lynx.

If you’re wondering why that list is full of animals that don’t actually live in Scotland these days, like the brown bear and lynx, it’s because humans hunted many of the native Scottish animals to extinction. Others went extinct due to habitat loss or competition with introduced animals. Many surviving species are endangered today for the same reasons.

For example, the Scottish wildcat, also called the Highland wildcat. We talked about it briefly in episode 52 way back in early 2018. One of the animals that migrated to Scotland after the Pleistocene, but before sea levels rose and cut the British Isles off from Europe, was the European wildcat. The Scottish population has been separated from the European population for at least 7,000 years, and some researchers think it should be classified as a subspecies of European wildcat.

The Scottish wildcat is a little larger than a domestic cat and is always tabby striped. It has a bushy tail with a black tip, a striped face and legs, never any white markings, and is usually dark in color with black paws. It’s a solitary animal that mostly lives in woodlands, where it eats mice, voles, and other rodents, rabbits, and birds. It used to be common throughout much of the British Isles, but these days it’s only found in parts of Scotland.

You’d think people would be excited to have a genuine wildcat living in their country, since wildcats are pretty awesome and eat animals that can damage crops. But for some reason, until recently people thought these wildcats were pests and would shoot them on sight. Some people thought the wildcats were killing game birds, which is rare, or that they were dangerous, which isn’t true. At the same time, the people shooting wildcats were letting their domestic cats roam freely, which has caused an even bigger problem to wildcats than getting shot at.

Like other wildcat species, the Scottish wildcat can and will cross-breed with domestic cats. The resulting kittens are fertile, meaning they can have babies with either wildcats or domestic cats. Kittens are great, of course, but domestic cats are a different species from wildcats. Hybrid cats are less suited to live in the wild, but too wild to be good pets, and if too many domestic cats breed with wildcats, soon there won’t be any real wildcats left. Not only that, domestic cats carry diseases that wildcats can catch.

The Scottish wildcat is a protected species these days, with conservation efforts in place to keep the wildcats and their habitat as safe as possible. One important step is to encourage people to get their domestic cats neutered. This is healthier for pet cats anyway and will help keep tomcats from spraying and fighting, and of course it stops them from having kittens with wildcats.

Another felid that once lived in Scotland is the Eurasian lynx. It still lives in parts of Asia and Europe, but it went extinct in Scotland several hundred years ago, mainly due to deforestation and hunting for its fur. It’s about 28 inches tall at the shoulder, or 70 cm, and is a heavily built animal with thick spotted fur and a short bobtail. The tip of its tail is black although the rest of the animal is mostly tan or brown with darker brown spots, and it has long black tufts of fur on the tips of its ears. It’s slightly bigger than the related Canadian lynx.

Conservationists have wanted to reintroduce the Eurasian lynx to Scotland for years. Since the lynx is threatened in the rest of its range by habitat loss and hunting, reintroducing it to its former range in Scotland would help it and the ecosystem in general. With no large predators to keep their numbers in check, the population of roe deer in Scotland is too high to be healthy, and the lynx loves to eat roe deer.

Some people worry that if the lynx is reintroduced to Scotland, it will be dangerous to humans and livestock. But the lynx is a shy, solitary animal that avoids humans as much as possible. There are enough roe deer alone to sustain a population of over 400 lynxes in the wilder parts of Scotland, especially in the Highlands. The lynx also spends almost all of its time in forests and doesn’t like open pastures. It’s been successfully reintroduced to its former range in other countries, with a nice side effect being increased tourism to national parks where it’s now found.

Scotland also used to have beavers, which were hunted to extinction in the 16th or 17th century. Then, in 2009, the Eurasian beaver was reintroduced to parts of Scotland and is doing great! There are more than 1,000 beavers living in Scotland now. Beavers are considered a keystone species, a term we haven’t really examined on the podcast before, but it means that an animal is so important to an ecosystem that if it goes extinct in an area, the ecosystem sort of falls apart and many other animals go locally extinct soon after.

Beaver ponds create a winter habitat for many types of fish, and beaver dams don’t stop fish like salmon that migrate upriver to spawn. The dams help reduce flooding, improve water quality, and create cover for lots of fish and other animals.

Naturally, though, some people complain about the beavers, because there will always be someone who complains about anything. Some people think beavers eat fish and will eat up all the fish that humans want to catch. Beavers actually don’t eat fish at all, they only eat plant material. Some people think beavers carry the giardia parasite, which causes a bacterial infection sometimes called beaver fever that’s spread in water, but giardia is actually mostly spread by domestic dogs. Some people complain that beavers fell trees and build ponds, and both these things are true. But the beaver is just doing what it’s supposed to do, and as we just learned, this tree felling and pond-making are good for the environment—unlike humans, who chop down lots of trees and make artificial ponds when landscaping, while simultaneously draining wetlands, which doesn’t help the local environment at all. Besides, the beavers are cute and attract tourists who want to get pictures of them, which is also good for the local economy. Everybody wins when there are beavers around, is what I’m trying to say.

The beavers reintroduced in 2009 aren’t the only beavers in Scotland. In 2001, people started seeing them around the river Tay—but no one knew where they came from. Well, presumably someone knew, because the beavers didn’t get there without help. If this reminds you of episode 48, where we talked about some mystery beavers that appeared in Devon, England, the Devon beavers showed up in 2013, twelve years after the Scottish mystery beavers. At first the Scottish government planned to capture the Tayside beavers and keep them in captivity, but the beavers are still there and doing very well.

It’s great that over a thousand beavers live in Scotland now, but that’s actually not very many. Still, it’s a whole lot better than the number of Eurasian beavers about 150 years ago, when researchers think there may have been as few as 300 individuals alive in the whole world.

Another animal that once lived in Scotland, was hunted to extinction, and then mysteriously reappeared recently is the wild boar. They first appeared in the 1990s and by now there are thousands of them in Scotland. It’s possible they escaped from farms, where they’re sometimes raised for meat like domestic pigs. While they’re a native species, they don’t have any predators in Scotland and are causing a lot of damage as they become more numerous. The wild boar’s natural predator is the wolf, and the last wolf in Scotland was killed in 1743. Lynxes will also kill wild boar piglets.

Some birds have been reintroduced to Scotland too. The white-tailed eagle is a type of sea eagle, closely related to the bald eagle of North America although it’s slightly larger than the bald eagle. The biggest ever reliably measured was a specimen from Greenland with a wingspan of 8 feet 4 inches across, or 2.53 meters, just a smidge larger than the largest bald eagle wingspan known. It’s mostly brown and gray with a yellow bill and feet, and a white tail. It lives around water and eats a lot of fish, but it also eats lots of carrion, gulls and other birds, and occasionally small mammals like rabbits. It always lives near water but it prefers wooded areas, especially lowlands and forested islands.

The white-tailed eagle went extinct throughout Britain in the early 20th century when people decided they wanted all those fish the eagle eats for themselves. Never mind that even a thousand eagles couldn’t eat as many fish that a single commercial fishing boat catches in a day. People also decided that eagles killed lambs, even though this is extremely rare. White-tailed eagles would much rather eat fish and seagulls than lamb. The last white-tailed eagles in Scotland were shot and killed in 1916.

As if that wasn’t bad enough, white-tailed eagles were also killed throughout the rest of their range and were especially vulnerable to the chemical called DDT. DDT was a popular pesticide developed in the 1950s and used to kill insects on crops and gardens. But DDT is dangerous, because like other pesticides it doesn’t just do its job and evaporate. It stays in the environment and ends up in the bodies of animals, including people. It’s especially bad for birds that eat a lot of fish, since a lot of pesticides end up in the water, and it causes their eggshells to become so thin and weak that the eggs break when the mother tries to keep them warm. This is the same thing that almost drove the bald eagle to extinction in North America. By the time DDT use was banned in many countries and the white-tailed eagle was declared a protected species, it was almost too late.

Conservation efforts have helped stop the white-tailed eagle from going extinct and its numbers are slowly growing. Starting in 1975, young eagles were brought from Norway to Scotland, where they were successfully reintroduced in the inner Hebrides islands and have now expanded to other parts of Scotland. Some people still complain about the eagles and sometimes shoot or poison them even though it’s illegal, but most people are happy to have them around, especially birdwatchers.

Scotland even has some reindeer these days. Reindeer probably lived in Scotland until around the 12th century, and in 1952 a Swiss herdsman thought they should still be there. He brought a small herd to the Cairngorm mountains, which is now a national park. The reindeer are semi-domesticated but roam free, and they attract tourists who hope to catch a glimpse of them.

At the same time that many native animals have gone extinct, lots of non-native animals have been introduced to Scotland, including wallabies, American mink, gray squirrels, various species of crayfish, and many more. Conservationists are working to minimize the damage these introduced species cause. Many invasive species were animals kept as pets that either escaped or were released into the wild. We talked about the invasive eastern gray squirrel versus the native red squirrel in episode 241, for instance. People released gray squirrels into parks in England because they were so cute, and a hundred years later, the gray squirrels are taking over in many places. They’re increasingly common in Scotland, although Scotland has a small predator called the pine marten that loves to eat squirrels.

The pine marten is a type of mustelid, or weasel relative, that’s common throughout much of Europe and Asia. It grows about two and a half feet long, or 75 cm, including its bushy tail. It mostly lives in wooded areas and spends a lot of its time in trees, hunting squirrels and other small animals like frogs, insects, and birds. It will also eat carrion, bird eggs, and sometimes fruit. It’s mostly brown with a cream-colored throat. It even has partially retractable claws like a cat to help it climb trees, although it’s not related to the cat.

The pine marten is especially good at catching squirrels, and it tends to target the gray squirrel because it’s easier to catch. The red squirrel is more cautious. Where there are pine martens, there are fewer or no gray squirrels. The problem is, the pine marten is considered a pest that kills game birds, so some people shoot or poison it even though it’s a protected species. Then those same people complain about all the gray squirrels around. The pine marten is doing well in many parts of Scotland, though, and has even expanded its range slightly in the last few years.

Scotland is a beautiful country known for its wild and rugged countryside. It wouldn’t take much to rewild it properly, a process that’s well underway with keystone species like beavers already re-established in many places. The main problem is people who don’t understand that a healthy ecosystem requires predators. Without lynxes, wolves, bears, and other large predators, animals like roe deer and wild boar become so numerous that they can’t find enough to eat and either starve or destroy crops and gardens.

Fortunately, many more people in Scotland do understand the importance of building healthy ecosystems. After all, they’re naturally proud of where they live and want to make it even better.

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 276: Hominins and Art



It’s Nicholas’s episode this week, and Nicholas wants to learn more about hominins, the ancestors and cousins of modern humans!

Happy birthday to Autumn! I hope you have a great birthday!

Further listening:

Humans Part One

Further reading:

Were Neanderthals the Earliest Cave Artists?

Neanderthals Built Mysterious Stone Circles

DNA reveals first look at enigmatic human relative

What does it mean to have Neanderthal or Denisovan DNA?

Hand and footprint art dates to mid-Ice Age

Risky food-finding strategy could be the key to human success

A stone circle in a cave was probably built by Neandertals:

A deer bone with carving on it probably made by Neandertals:

Some cave paintings probably made by Neandertals:

Show transcript:

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

This week is Nicholas’s episode! Nicholas wanted an updated episode about hominins, our ancient ancestors or species closely related to modern humans. The last time we talked about hominins was way back in episodes 25 and 26, so it’s definitely time to revisit the topic.

But first, a big birthday shout-out to Autumn! Happy birthday, Autumn, and I hope you have the best birthday so far!

If you haven’t listened to episode 25 in a while, or ever, I recommend you go back and give it a listen if you want background information about how humans evolved and our closest extinct relatives, Neandertals and Denisovans. I’ve transcribed that episode finally, so you can read the episode instead of listen to it if you prefer. There’s a link in the show notes.

Results of a study published in January 2022 in the journal Nature has finally dated the oldest known Homo sapiens remains found so far. The remains were found in Ethiopia in the 1960s but the volcanic ash found over them was too fine-grained to date with any certainty. Finally, though, the eruption has been determined to come from a volcano almost 250 miles, or 400 km, away from the remains. The Shala eruption was enormous and took place 230,000 years ago, so since the remains were found below the ash, the person had to have lived at least 230,000 years ago too.

We’re still learning more about humans and our closest relations because new hominin fossils are being found and studied all the time. But the fossil record doesn’t tell the whole story. Only a small percentage of bones ever fossilize, and of those, only a tiny fraction are ever found by scientists. But technological advances in genetic testing means that scientists can now extract DNA from the soil. All animals shed fragments of DNA all the time, from skin cells and hairs to poop. A study published in 2021 was able to isolate Neandertal DNA from sediments in three different caves. The DNA matched the known fossils found at the sites and gave more information besides. Instead of being restricted to a single individual whose bones were found and tested, genetic testing of sediments gives genetic information about lots of individuals. In the case of a cave in northern Spain, where lots of stone tools have been found but only a single Neandertal toe bone, it turns out that two different populations of Neandertal had lived in the cave over 100,000 years ago.

In episode 25, I mentioned that Neandertals didn’t seem to make things the way humans do, especially art. Some researchers even suggest that they couldn’t think symbolically the way humans do. But in the five years or so since that episode, we’ve learned a lot more about Neandertals–and they seem to have been pretty artistic after all.

The main problem is that historically, whenever scientists found rock art or carvings from prehistoric times, they assumed humans made it. We might be a little biased. Some art originally thought to be made by humans is now thought to have been made by Neandertals. Most of it is found in caves. Remains of animals are often found in caves because the cave protects them from weather and other factors that can destroy them, and the same is true for archaeological remains.

In 1990, a team of cavers dug into a narrow collapsed cave entrance and entered Bruniquel Cave in southwest France that no human—in fact, no animal from the surface world—had entered since the entrance collapsed during the Pleistocene. That was at least 24,000 years ago and probably much, much longer.

The cavers found the bones of long-extinct Pleistocene megafauna near the entrance, including cave bears. But it wasn’t until they reached a chamber deeper inside the cave that they made a stupendous discovery.

The chamber held a big stone circle made of broken-off pieces of stalactite and stalagmite and other rock formations. The pieces are all about the same size and are arranged in a circle almost 22 feet across, or 6.7 meters. There’s a smaller semicircle in the chamber too and heaps of more stone pieces. Some of the stones show signs of fires being lit on top of them, and a piece of burnt bone from a bear or other large animal was found near the semicircle.

The cavers alerted local scientists, who came to investigate. At first they thought the structures had been built by early humans. They took samples for testing, and that’s when they got another shock. The burnt bone, the fire residue, and the minerals growing over both revealed an age long before 40,000 years ago, which is when humans first moved into the area. The stone circle was built 176,000 years ago. And the only hominin known to live in Europe that long ago was the Neandertal.

We don’t know what Neandertals used the stone circles for. It might have been a living space, but it might have been religious in nature instead. Either way, it shows that even that long ago, Neandertals had full control over fire to the point that they could make light sources to find their way deep into a cave, and had the curiosity to want to explore deeper into a cave than they really needed to go for shelter.

There are lots of other examples of Neandertal art and intelligence found in Europe. For instance, paintings in a cave in Spain have been dated to at least 65,000 years ago. Remember, humans didn’t reach Europe until about 40,000 years ago. The paintings are made of red mineral pigment, including elaborate rows of dots, geometric figures, and occasionally animal figures and hand stencils. Other caves in the area also have similar rock art dating to Neandertal times.

In a cave in Germany, researchers found a piece of deer bone dated to 51,000 years ago that has a carved pattern in it. The carving is too elaborate to be simple butcher marks, but again, humans hadn’t yet moved into Europe 51,000 years ago. The bone actually comes from the leg of a giant deer, once called the Irish elk, that we talked about way back in episode 4. In another cave in Gibraltar, cross-hatched patterns carved in the rock have been dated to more than 39,000 years ago and are associated with artifacts made by Neandertals.

Archaeologists have also found a lot of toe bones from eagles that are etched with cut marks, found in various sites throughout southern Europe. They think Neanderthals in this area wore eagle talons as jewelry, and most likely feathers too.

There’s still controversy when it comes to Neandertals and art. Some researchers think Neandertals only used art after they saw humans making it. Some think the art isn’t art at all but something else, like accidental marks left by other activities. Some think the dating methods used to determine the age of paintings is flawed.

Another criticism is that we don’t actually know that Neandertals made the art; we just know it probably couldn’t have been humans. But there were other human relations living at the same time.

One of those is the Denisovan people, named for Denisova Cave in the mountains of Siberia. Hominins didn’t ordinarily live in caves, but sometimes they did. This seems to be the case in Denisova Cave, where evidence of human habitation, Neandertal habitation, and habitation by another hominin goes back some 180,000 years.

Researchers knew about humans and Neandertals living in the cave, but it wasn’t until 2010 that they realized a third hominin had lived there at various times. The Denisovan people were closely related to both Neandertals and humans and probably looked a lot like Neandertals, with a robust build and big teeth. We still don’t know a whole lot about them, but they lived in parts of what is now Asia and possibly nearby areas, and they might not have gone extinct until about the same time that Neandertals did, around 30,000 years ago.

We talked about the Denisovans in episode 25, but since then new remains have been discovered in other caves. The most exciting is a partial jawbone with two teeth that was found by a Buddhist monk in a cave on the Tibetan plateau in 1980, but not studied until much later. It was identified as a Denisovan mandible in 2019 and dated to 160,000 years ago.

Genetic testing of Denisovan remains indicate that Denisovans and Neandertals were probably more closely related to each other than to humans, although all three species were very closely related. Since there are so few Denisovan remains known, we don’t have a very good idea yet of where they lived and what they were like. We do have genetic markers that indicate the Denisovans had dark skin, brown hair, and brown eyes, while Neandertals, like humans, were more varied in skin, hair, and eye color.

Geneticists have identified traces of Denisovan DNA in some populations of modern humans, including in Asia, New Guinea and surrounding areas, and Australia. This is a reminder that even though some human populations contain DNA traces from our extinct cousins, all humans are thoroughly human. Those bits and bobs of ancient DNA are too small to be significant.

We do have what seems to be art made by Denisovans, although not everyone agrees that it was intended to be art in the way we think of it. It was found in the Tibetan Plateau and we now know that Denisovans lived in the area, although when it was found in 1998 we didn’t even know Denisovans existed. The art was found near hot springs and dated to as much as 226 thousand years ago, although it might have been closer to 169 thousand years ago. Either way, it was well before modern humans are known to have lived in the area. The art consists of footprints and hand prints pressed into the mud, probably by two individuals. The artists pressed their hands, feet, fingers, thumbs, and in one case a forearm into the mud around the hot springs, making patterns. But the thing is, these prints are small even by human standards. Researchers are pretty sure they were made by children, so while it’s certainly possible the children were creating art, they also might just have been messing around having fun in the mud. But the fact that they were making patterns points to an artistic intelligence. Puppies play and may stomp their feet in mud, but they don’t get interested in making patterns of their footprints in the mud. Human children do.

There’s still at least one other hominin that lived at the same time as Neandertals, Denisovans, and humans. We only know about that hominin because researchers have identified their DNA in genetic studies of Denisovans, which means they interbred. It’s a ghost lineage that no one guessed existed until genetic studies of Denisovans and Neandertals were completed in the early 2010s. It might turn out to be a known hominin such as Homo erectus but it might be a completely unknown species.

Of course we have lots of information about art made by ancient humans. It’s been found throughout the world. No one’s in any doubt that our prehistoric ancestors were just as intelligent and artistic as humans who live today, they just didn’t have the technology we have. I can go to an art supply store and buy paints in any color I want, assuming I don’t just want to paint digitally, but in prehistoric times human artists had to make their own paints from the things they found in nature. This included minerals like red ochre and yellow ochre, umber, calcite, hematite, iron oxide, and lots more. They used burnt bones and charcoal for black. These minerals are all still used to make modern oil paints (used in art, not for painting a room or a house), with names like bone black and lime white.

Many minerals have to be processed before they can be used as pigments. Ochre, for instance, has to be heated to 850 degrees Fahrenheit, or 750 Celsius, to change into the rich red-orange that ancient artists especially liked. After processing, the pigments were ground into powder, then mixed with various substances to make a paste. These substances included fat, blood, spit, plant oils, tree sap, water, bone marrow, and even urine.

Ancient artists used their fingers to paint, but they also used twigs, brushes made from animal hair, and mats of lichen. Sometimes they blew pigment onto a surface with their breath, first putting the paint into a hollow tube and then blowing into the tube to spray paint. This is the same way airbrushes work, but no one gets light-headed using an airbrush because a machine is doing the blowing air part. If the artist was working in a cave, they also needed a light source, specifically fire, so they could see what they were doing. It’s all a lot of work.

Aside from all the details involved in getting ready to paint, making art takes one other really important commodity: time. Great apes spend most of their time finding food and eating it. How did ancient humans find time to paint without starving?

A study released in early 2022 points out that hominins developed a much different strategy for getting food than our more distant ape relations. Apes mostly eat plant material, especially fruit, which is nutritious but takes a lot to fulfill the calorie needs of an adult. Early hominins were hunter-gatherers, meaning they both hunted animals and gathered plant material to eat. But because hominins are intensely social and share food, we could take risks that other animals can’t. A group of ancient humans could go out to hunt something big knowing that even if they failed, when they got home they wouldn’t go hungry. Other people would have been gathering food all day and would share. But if the hunters got lucky and brought home a big animal like a deer, everyone had lots and lots of high calorie food to go around. With food available to everyone, people could take time to do things that didn’t directly relate to finding food, like art.

Not only that, another study published in 2019 discovered that some early hominins had already figured out how to preserve food several hundred thousand years ago. The food in question was bone marrow, which is found inside bones and which is extremely nutritious. Researchers have always assumed hominins would crack the bones of animals they killed to get at the marrow as soon as possible. But deer bones found in a cave near Tel Aviv, Israel were stored unbroken, with the skin still on. Researchers determined that the bones were kept in the cave for up to nine weeks before being broken open. By keeping the skin on the bones and storing them in the cave, where the temperature was cool, the marrow stayed fresh. That way there was always something nutritious to eat in the cupboard, so to speak.

Art doesn’t have to be paintings or carvings. Ancient humans were probably using plant fibers to make things more than 34,000 years ago. The fibers are from wild flax plants, and flax is still used today to make linen fabric. Fragments of flax fibers were found in a cave in the Republic of Georgia (which is a country, not the American state of Georgia) where other human artifacts were found. Since flax isn’t edible, at least not by humans, researchers think the fiber might have been used to make thread, rope, baskets, and possibly even cloth. You know, clothing.

One thing to remember is that humans, Neandertals, and Denisovans were so closely related that they could and did interbreed and produce fertile offspring. That means not only were our extinct cousins very similar to us physically, they were probably pretty similar to us mentally too. It would be more surprising if they didn’t produce art that represented symbolic thinking, since it’s such an important part of the human experience.

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 275: The Axolotl, the Hellbender, and Friends



This week it’s Zoe and Dillon’s episode! They wanted to learn about some really interesting salamanders, including the axolotl and the hellbender!

A big birthday shout-out to Heather R. too. The very happiest of birthdays to you!

Further reading:

Mexico City’s endangered axolotl has found fame—is that enough to save it?

How Do Salamanders Breathe?

Most wild axolotls are brown:

Most captive-bred axolotls are leucistic:

The hellbender doesn’t have external gills as an adult:

The red eft, the juvenile stage of the red-spotted newt:

Adult mudpuppies have external gills just like axolotls do:

Show transcript:

Welcome to Strange Animals Podcast. We’re your cohosts, Zoe and Dillon. And I’m your third cohost, Kate Shaw.

This week we have Zoe and Dillon’s episode, and they want to learn about the axolotl, the hellbender, and some other salamanders. It’ll be the greatest amphibian episode ever!

But first, we have a birthday shout-out! Happy birthday to Heather R.! I hope the weather is perfect for your birthday and you get to go out and appreciate it.

So, let’s start with the axolotl, because everyone loves it! “Axolotl” isn’t the way it’s pronounced in its native country of Mexico, since it comes from the name of an Aztec god of fire and lightning, but it’s the common pronunciation in English so I’m going to stick with that one. In addition to Zoe and Dillon, at least one other listener has suggested we cover the axolotl. That would be Rosy, and I apologize to anyone else who suggested it but whose name didn’t make it onto the suggestions list.

Way back in episode 104, about tiger salamanders, we learned that the tiger salamander is closely related to the axolotl. But the two species look very different most of the time because the axolotl exhibits a trait called neoteny. In most salamanders, the egg hatches into a larval salamander that lives in water, which means it has external gills so it can breathe underwater. It grows and ultimately metamorphoses into a juvenile salamander that spends most of its time on land, so it loses its external gills in the metamorphosis. Eventually it takes on its adult coloration and pattern. But the axolotl doesn’t metamorphose. Even when it matures, it still looks kind of like a big larva, complete with external gills, and it lives underwater its whole life.

Very rarely, an axolotl metamorphoses into an adult form, at which point it looks a whole lot like a tiger salamander. This generally happens if the individual is exposed to excess iodine in its diet, and metamorphosing like this may actually lead to the axolotl’s death. Axolotls exhibit neoteny because it gives them an advantage in their natural range, so even though it seems strange to us compared to all those other salamanders, it’s what the axolotl is supposed to do.

The axolotl’s natural range is very specific. Originally it lived in two large, cold lakes in the Valley of Mexico. This is where Mexico City is and it’s been a hub of civilization for thousands of years. A million people lived there in 1521 when the Spanish invaded and destroyed the Aztec Empire with introduced diseases and war. The axolotl was an important food of the Aztecs and the civilizations that preceded them, and if you’ve only ever seen pictures of axolotls you may wonder why. Salamanders are usually small, but a full-grown axolotl can grow up to 18 inches long, or 45 cm, although most are about half that length.

Also if you’ve only ever seen pictures of axolotls you may think they’re all white or pink. That’s actually rare in the wild. Most wild axolotls are brown, greenish-brown, or gray, often with lighter speckles. They can even change color somewhat to blend in with their surroundings better.

It’s captive axolotls that are so often white or pink, or sometimes other colors or patterns. That’s because they’re bred for the pet trade and for medical research, because not only are they cute and relatively easy to keep in captivity, they have some amazing abilities. Their ability to regenerate lost and injured body parts is remarkable even for amphibians, but, interestingly, axolotls that have been induced to metamorphose have much less regeneration ability. Researchers study axolotls to learn more about how regeneration works, how vertebrates evolved various aspects of anatomy, how genetics of coloration work, and much more. They’re so common in laboratory studies that you’d think there’s no way they could be endangered—but they are. Some conservationists think there may be as few as 50 individuals left in the wild.

The main problem is habitat loss. One lake where the axolotl was once found is completely gone, drained to control flooding and provide more land for people to use. The other lake isn’t so much a lake anymore as a series of canals in Mexico City, and they’re polluted and home to introduced species of fish that eat axolotl eggs. Even though part of their range was designated as a nature reserve in 1993, that hasn’t done much to stop the pollutants or invasive fish.

Not only that, the captive-bred axolotls are so different from their wild cousins that some people think they should be considered a different species. You couldn’t take a pet axolotl and dump it into a lake and expect it to live. Conservation efforts in Mexico are focusing on a captive breeding program of axolotls caught in the wild. Since the salamander’s native range isn’t healthy right now, the group is trying to establish temporary homes in university ponds prepared just for that purpose. So far the project is a success.

At the same time, conservationists and just regular people who like axolotls are working hard to get its native habitat cleaned up. This includes educating people about the axolotl, and helping people set up small farms that use traditional methods that don’t require fertilizer or insecticides that run off into the water. These farms are called chinampas and are made up of artificial islands with canals around them. The islands actually help filter pollutants from the surrounding water, and the canals are ideal for axolotls to live in. The farmers also install screens with filters to keep invasive fish out and clean up the water even more, and some of the captive-bred wild axolotls have been introduced to these canals successfully.

Even though the axolotl has external gills to collect oxygen from the water, it has lungs too. It will sometimes gulp air from the surface, but most of the time it gets all the oxygen it needs from its gills. It eats small animals like worms, insects, and even small fish, but while it does have tiny teeth, they’re actually vestigial. The axolotl doesn’t chew its food but instead sucks its prey whole right down into its stomach.

We talked about the hellbender briefly in episode 14, but that was five years ago. In fact, it was exactly five years ago. Episode 14 was released on May 8, 2017, and this episode is being released on May 9, 2022. I swear I did not plan it that way but it’s pretty neat.

The hellbender has a restricted range too, although it’s not as restricted as the axolotl’s. It lives in parts of the eastern United States, especially in the Appalachian Mountains and the Ozarks. It can grow nearly 30 inches long, or 74 cm, and is heavy for its size, up to 5.5 lbs, or 2.5 kg. This is the fifth heaviest amphibian alive today in the whole world! It needs clean, shallow, fast-moving streams with lots of rocks, because it spends almost all its life in the water hiding among rocks. But the rocks are important for another reason too. As water rushes over and around rocks, it splashes around and absorbs more oxygen. Well-oxygenated water helps the hellbender breathe, which is even more complicated than it sounds.

Like other salamanders, the hellbender hatches from eggs laid in the water and at first are just big tadpoles with external gills. They metamorphose in stages until they’re full grown at almost two years old, at which point they lose their gills, although they may retain a nonfunctioning gill slit. The adult hellbender has large lungs, but it doesn’t use them for breathing. They’re just for buoyancy. The hellbender absorbs oxygen from the water through its skin, which is why it needs well-oxygenated water flowing quickly across it all the time. To increase its surface area and help it absorb that much more oxygen, its skin is loose and has folds along the sides.

The hellbender is flattened in shape, which helps it hide under rocks and helps keep it from being swept away by currents when it’s moving around in the water. It’s brown with black speckles on its back. It mostly eats crawdads, also called crayfish, but it will eat small fish and amphibians, tadpoles, the eggs of frogs and fish, and in fact it will also eat the eggs of other hellbenders. Occasionally a hellbender will eat a smaller hellbender too. It’s a solitary animal except during breeding season, and even then, once the female has laid her eggs in a nest the male makes and the male fertilizes them, the pair don’t spend any time together. The male actually chases the female away. Then he spends the next few months guarding the eggs and making sure they get enough oxygen by waving his tail and skin folds over them.

The hellbender doesn’t have very good eyesight, although it has a good sense of smell. It’s very territorial and seldom leaves the small stretch of water where it lives and hunts. Very occasionally it will leave the water and walk around on land. Most of the time it walks around underwater, though, instead of swimming. Its toes have rough pads that help it walk even on slippery rocks. During the day, though, it usually hides under its home rock. Its skin contains light-sensitive cells, which are mostly concentrated in its tail. This means that it can actually sense how much light is shining on its body even if its head is hidden under a rock. The reason its tail has more light-sensing cells is because its tail is more likely to be sticking out from under its rock. Since a lot of animals eat the hellbender, it needs to be fully hidden by its rock during the day.

Some people think the hellbender is poisonous or venomous, but it’s actually completely harmless unless you are a very small aquatic animal.

Because salamanders, like other amphibians, have to keep their skin moist, they’re vulnerable to water pollution. Any pollutants in the water are liable to be absorbed into the salamander’s body, which can make it sick. Habitat loss, disease, and invasive species are also major causes of declines in salamander species.

Salamanders have been around for at least 180 million years. Amphibians in general probably developed from lobe-finned fish around 360 million years ago. A study published in 2020 examined 3D scans of skulls from 148 species of salamander to compare minute differences and learn more about how they evolved. Animals that undergo metamorphosis, including salamanders, have very different skulls from animals that don’t, since different parts of the skull develop in stages independently of other parts. The study found that while salamanders have always been metamorphic, different life cycles have evolved separately at least eleven times.

One of the things Zoe asked in particular was whether salamanders actually breathe through their nostrils. It depends on the species. Salamanders are definitely complicated when it comes to breathing. Like many amphibians, the salamander doesn’t have special muscles to move air in and out of its lungs the way mammals do. Instead, it moves air in and out by gular pumping, also called buccal pumping.

A salamander lowers the floor of its mouth, expanding the throat, which pulls air into the throat by way of the nostrils. Then the salamander closes its nostrils and raises the floor of its throat. This causes the air to enter the lungs. It does the same process in reverse to breathe out. That’s why salamanders and other amphibians appear to be gulping all the time. That’s how they breathe.

Complicated as this sounds, the salamander doesn’t have to concentrate to do it any more than we have to concentrate to breathe. Also, even if it mostly gets oxygen through its lungs, all salamanders appear to be able to absorb a certain amount of oxygen through the skin too.

Zoe and Dillon were especially interested in salamanders that live in their part of the world, which is the state of Pennsylvania in the eastern United States. In addition to the hellbender, there are several dozen salamander species known from Pennsylvania, and probably quite a few that haven’t been discovered yet. This includes the red-spotted newt, which lives in forests in muddy or wet areas. It grows up to about 5 inches long, or 13 cm, and eats insects, worms, frog eggs and tadpoles, and other small animals.

As an adult, the red-spotted newt is greenish-brown, often with a row of red spots outlined with black along its sides and tiny black dots all over, and a yellow or orange belly. The adult mostly lives in the water, but during the juvenile stage it mostly lives on land and can travel widely, especially after rain. It also looks very different during the juvenile stage, with a bright orangey-red body and spots outlined with black, which is why it’s often called a red eft. An eft is a juvenile salamander. The bright red coloring may tell you not to eat the red eft, because it’s poisonous! Its skin contains toxins that make it taste bad and can make a potential predator sick.

Another salamander common throughout Pennsylvania is the spotted salamander, which can grow almost 10 inches long, or 24 cm. It’s a big, strong salamander that’s black or gray with big yellow or orangey spots all over. As a juvenile it looks very similar, although smaller, but with tiny spots or no spots.

Finally, to wrap around to where we started, another large species of salamander that lives in parts of western Pennsylvania, and other nearby areas, is the mudpuppy. It looks a lot like a juvenile hellbender but isn’t as big, with the largest measured adult growing just over 17 inches long, or almost 44 cm. Like the axolotl, the mudpuppy exhibits neoteny. It lives in lakes, ponds, and streams and retains its gills throughout its life. Its gills are large and reddish in color. If a mudpuppy lives in your pond or backyard stream, you can be sure the water is clean because its gills are very sensitive to pollutants.

The mudpuppy spends most of its time under rocks and walking along the bottom of the lakebed or streambed, looking for food. It’s gray, black, or reddish-brown, sometimes with speckles or spots. It has a lot of tiny teeth where you’d expect to find teeth, and more teeth on the roof of its mouth where you would not typically expect to find teeth. It needs all these teeth because it eats slippery food like small fish, worms, and frogs, along with insects and other small animals.

Even though the mudpuppy has all those teeth, it’s harmless to humans and just wants to be left alone, but that’s pretty much the case for all salamanders. And some people.

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 274: Mystery Big Cats in Australia



Thanks to Kristie and Jason, we’re going to learn about some mystery big cats reported in Australia, in particular Victoria.

Further reading:

Official big cat hunt declared a bust, so why do people keep seeing them?

Further watching:

Thylacine video from 1933, colorized

You’ll probably need to enlarge this but it’s a still from a 2018 video purportedly showing a mystery big cat, but in this frame you can see the ears are pointy, which is a sure sign of a domestic cat:

A melanistic (black) leopard and regular leopards (picture from this site). If you zoom in you can see the spot pattern on the black leopard:

A puma/cougar/mountain lion. Note the lack of spots:

A thylacine. Note the lack of spots but presence of stripes:

Show transcript:

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

This week is Kristie and Jason’s episode. They want everyone to learn about mysterious big cats in Australia!

Australia, of course, is home to many wonderful animals, but almost all of the native mammals are marsupials. There are no native felids of any kind in Australia, even in the fossil record. This is because Australia split off from the rest of the world’s landmasses when the supercontinent Gondwana broke apart. Marsupials actually first arose in South America and spread to Australia when the two landmasses were connected. Then, around 180 million years ago, South America and Africa split off from the rest of Gondwana, including Australia. Most of South America’s marsupials went extinct as placental mammals arose and became more and more numerous, but Australia was on its own starting about 30 to 50 million years ago. Marsupials never had to compete with placental mammals during most of that time, except for bats, and the marsupials thrived.

Humans first populated Australia at least 41,000 years ago and probably more like 65,000 years ago. The first dingoes, a type of dog, were introduced around 5,000 years ago. The first European sighting of Australia was in 1606, and less than 200 years later the British colonized the continent, bringing with them invasive species like cats, rats, cattle, sheep, foxes, rabbits, deer, and lots more, which have driven many indigenous animals to extinction. But while domestic cats are common in Australia, as far as we know no one has ever deliberately released enough big cats to form a breeding population.

In that case, though, why are there so many reports of big cats in parts of Australia?

If you remember way back in episode 52, where we talked about big cats in Britain, there were lots of stories and a certain amount of evidence that individual big cats were occasionally found in the country. Ultimately, though, there’s no proof of a breeding population of big cats. The same is more or less true in Australia, but Australia is so much bigger and so much less populated than Britain, it would be easy for a small population of big cats to hide. And maybe they’re not actually big cats but some other animal, something that is native to Australia.

Kristie and Jason have lots of experience searching for big cats in central Victoria, Australia. They even helped with the research of a book about big cat sightings. Victoria is in southeastern Australia and is the smallest state. If you walked south from central Victoria to the coast, and then got on a boat and kept going south, you’d run into Tasmania. If you walked north instead, eventually you’d come to New South Wales but that is going to be a long walk. Victoria is mostly temperate and rainy but has tall mountains, semi-arid plains, and lots of rivers.

As Kristie pointed out, different parts of Australia have different stories about mystery big cats, but I’m mostly going to talk about sightings in Victoria, just to narrow it down.

To start us off, now that we have some background information, here’s a clip from the conversation I had with Kristie. The audio isn’t great, unfortunately, but it’s definitely interesting.

[quote of Kristie’s account:]

“Jason and I used to go puma hunting. It was very scary. So, there was this bloke we used to go and visit. I’m not going to name any names; I’m not even going to tell you exactly where he was other than he was in Castlemaine along a railway line, a disused railway line. So, the story goes that this man (let’s just take 80% of what he says with a grain of salt), he’d gone up to get a horse from a paddock outside their house that they lived in, on a dirt road near the railway. There was lots of long grass on the side of the road. He said he went to get the horse and was bringing the horse back to the house paddock, and he felt like he was being watched. Not a good feeling. And then he heard something that sounded like a growl coming from in the grass. And the horse had a bit of a moment. He continued on his way—he was safe, the horse was safe! No animals were hurt in the making of this story. From then on he said he and his wife would hear things walking around their house and it would just feel really weird. They would say that they actually saw these cats walking along the road.

“I would call Jason and we’d get on a motorbike and we’d go down, probably about a 5 or 10 minutes motorbike ride. Of course whenever we got there, there was nothing there. Occasionally you might see something on the dirt road, because there was a bit of fine dirt on there that maybe you could find a footprint on there.

“You would hear dogs bark, hear them off in the distance when whatever it was out there was on the move. It would actually follow the creek down and the railway line and you would get a succession of dog barks.”

Kristie went on to say that they’d even found and taken a plaster cast of a large paw print that looked different from a dog’s print, but the veterinarian they took it to wasn’t able to determine whether it was made by a big cat or just a dog.

She also talked about some other evidence that their friend gave as proof of big cats living in his paddock, including swirls in the long grass that looked like a cat had flattened the grass to sleep. In that case, she also pointed out that the same thing had happened in her own yard recently and that she was pretty sure it was caused by the wind. But here’s another clip from her about an experience she had that wasn’t so easy to explain:

[quote of Kristie’s account:]

“I spent one night out in a caravan that they had in their yard, just waiting, and I heard a cough. Pumas cough, but so do kangaroos, so I don’t know. I didn’t see any kangaroos. I like to think I heard a puma cough. I honestly don’t know what I heard.”

Kristie even thinks she spotted a big cat once as she and Jason rode by on a motorbike, but by the time she realized what she’d seen, it was long gone. She said it was a large black animal with a very long tail, much longer than a domestic cat’s tail.

One theory of big cat sightings is that they’re descendants of cougars, also called pumas or mountain lions, brought to Australia as mascots by American troops during World War II but released into the wild. While WWII units from various countries did often have mascots, they were usually dogs. A few mascots were domestic cats, there were a couple of pigs, birds, and donkeys, but mascots were almost always domesticated animals that a unit adopted even though they weren’t really supposed to have them. Wild animals were rare as mascots because they were hard to handle and hard to hide from officers. While there were certainly some big cats of various kinds brought to Australia by American soldiers and released when they started getting too big and dangerous to handle, or when they were found by officers, there wouldn’t have been enough to form a breeding population.

Besides, big cat sightings go back much earlier than the 1940s. Some people blame Americans again for these earlier stories, specifically American miners who came to Australia in the mid-19th century gold rush. Supposedly they brought pet cougars that either escaped or were released into the mountains. While miners did bring animals, they were almost always dogs or pack animals like mules.

More likely, though, any big cats escaped or released into the Australian bush in the olden days came from traveling circuses or exotic animal dealers. Even so, again, there just weren’t enough big cats of any given species to result in a breeding population. But, also again, people are definitely seeing something.

The most compelling evidence for big cats in Australia is attacks on large animals like horses, cattle, calves, and sheep. Australia doesn’t have very many large predators. Dingoes are rare or unknown in Victoria these days, as are feral pigs, foxes don’t typically hunt animals larger than a rabbit or chicken, and feral dogs usually leave telltale signs when they attack livestock.

In 2012, the Victorian Department of Sustainability and Environment commissioned a study of big cat sightings in the state. The study’s aim was to determine whether a breeding population of big cats might exist, and if so, what impact it was having on the native wildlife. The team examined historical and contemporary reports of big cats, and studied photos and videos and other evidence. Its findings were inconclusive—there just isn’t enough evidence that big cats are living in Victoria, although it couldn’t rule it out either—and it recommended further investigation.

An earlier study in the 1970s by Deakin University also attempted to determine whether big cats lived in the Grampians, a national park that includes a mountain range. Its traditional name is Geriwerd. The study came to the conclusion that there probably were pumas in the Grampians, but one of the pieces of proof, a 3-inch, or 8-cm, fecal pellet, was later identified as a pellet regurgitated by a wedge-tailed eagle.

Kristie also mentioned that the wedge-tailed eagle might be the source of some claw marks found on wildlife. The wedge-tailed eagle is a large, robust bird with a wingspan over nine feet across, or 2.84 meters, and it lives throughout Australia and southern New Guinea. It’s mostly black or brown in color and has a large hooked bill and large, strong talons. It often hunts in pairs or even groups and can kill animals as large as kangaroos. Larger species of wallabies and other native animals are the eagle’s natural prey but it also eats lots of introduced animals like rabbits and foxes, and occasionally kills lambs or piglets. It also eats a lot of carrion.

Eagle attacks don’t explain everything, though, such as claw marks found on horse rugs. Horse rugs are special blankets that horses wear, especially in cold weather. There are also reports of dead sheep and goats found dragged into trees or through fences, something a dog couldn’t or wouldn’t do but a leopard or other big cat could.

In 1991 a piece of poop, more properly called scat or feces, was turned into authorities and sent for testing. Initially reports said it looked like it came from a large felid, although what species couldn’t be determined. Fortunately it was saved and was genetically examined a decade or so later, at which point it matched up to a leopard. Assuming it was actually found in the bush and wasn’t a joke by an exotic pet owner, it means there was a leopard running around in central Victoria a few decades ago for sure.

Most sightings of Australian big cats fall into two categories: black cats and tan or gray-brown cats with white bellies. As we learned in last year’s wampus cat episode, the cougar is tan or gray-brown in color, sometimes called yellowish, with a pale belly, but is never black. Melanism is common in some big cats, especially leopards and jaguars, but leopards and jaguars are always spotted. Even melanistic individuals show a faint spotted pattern up close. So if some Australian big cats are black and other Australian big cats are tan or gray-brown without spots, they’re probably not the same species. But now it’s even more complicated! How could there be two species of big cat hiding so close to people without anyone hitting one with a car or shooting one in a pasture or just getting a really good picture of one on a trail cam or just a phone?

A lot of people think that feral domestic cats are responsible for all the sightings. While some feral cats can grow larger than average for a domestic cat, especially in areas where there’s lots to eat, most are actually quite small and thin. Feral cats are definitely responsible for a lot of big cat sightings, but not all. Black domestic cats in particular stand out in fields and on bright days so might be noticed more often than other colors of cat, and it’s easy to see a big black cat in the distance, not very close to anything, and assume it’s larger than it really is. But pictures and videos of these cats are usually pretty easy to identify as domestic. Domestic cats have pointy ears set high on the head, unlike big cats who have rounded ears that are lower on the head.

One video from 2018 is often cited as proof of a big cat in Australia, although in this case it’s in New South Wales. If you check the show notes, you’ll see a still I took from the video showing the animal’s ears. They’re pointy ears so the animal has to be a domestic cat.

There’s always another possibility, of course. Maybe the big cats aren’t cats at all but rare, reclusive carnivorous marsupials. The two main contenders are the marsupial lion and the thylacine.

The marsupial lion, or Thylacoleo carnifex, isn’t actually a lion. It’s a marsupial, and in fact I should say it was a marsupial because it went extinct at least 30,000 years ago as far as we know. It was probably almost as big as a lion, though, with massive jaws and teeth that could bite through bones. It ate large animals like the giant wombat relation Diprotodon and giant kangaroos, so it would have no trouble with a sheep.

But the marsupial lion didn’t actually look like a lion either. It probably resembled a small bear in some ways, although it had a thick tail more like a kangaroo’s than a cat’s. Its method of hunting doesn’t match up with the dead animals found in Victoria either. The marsupial lion had huge claws that it used to disembowel its enemies, I mean its prey, whereas modern big cats mostly use their strong jaws to bite an animal’s neck. Also, of course, the marsupial lion went extinct a really long time ago. While there’s always a slim possibility that it’s still hanging on in remote areas, I wouldn’t place any bets on it. I don’t think it’s the real identity of the mystery big cats. There are just too many discrepancies.

The thylacine, also called the Tasmanian tiger because it lived in Tasmania and had stripes, was about the height of a big dog but much longer. It was yellowish-brown with black stripes on the back half of its body and its tail. It had relatively short legs but a very long body and its tail was thick. It was a carnivorous marsupial, mostly nocturnal.

The thylacine went extinct in mainland Australia around 3,000 years ago while the Tasmanian population was driven to extinction by white settlers in the early 20th century. But like big cat sightings, people still report seeing thylacines. Maybe people are mistaking thylacines for big cats, since a quick glimpse of a big tawny animal with a long tail could resemble a puma if the witness didn’t see its stripes or didn’t notice them in brush or shadows.

The thylacine wasn’t a very strong hunter, though, at least as far as researchers can tell. But there’s a lot we don’t know about the thylacine even though it was still alive less than 100 years ago. As Kristie says:

“Maybe it was a thylacine. Who knows?”

Kristie and Jason think most big cat sightings are explainable as feral cats and other known animals. They also pointed out that what appear to be unusual predation methods might just be caused by more than one kind of animal scavenging an already dead carcass.

But there are lots of sightings that can’t be explained away, and people occasionally find dead animals that look like they’ve been killed and eaten by a big cat instead of a dog or eagle. While there’s a low probability that a breeding population of big cats is living in Victoria, there’s a very good chance that a few individual animals are. They’re most likely escaped or released exotic pets, possibly ones that were kept illegally in the first place.

As Kristie and Jason point out, people often freak out when they’re confronted with something strange, like the possibility that a leopard is sneaking around their house. You can’t really blame them. That’s why it’s so important to find out more about these animals, because turning the unknown into the known helps people know what to do and not be so scared.

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