Category Archives: extinct

Episode 291: The Ediacaran Biota

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This week let’s find out what lived before the Cambrian explosion!

A very happy birthday to Isaac!

Further reading:

Some of Earth’s first animals–including a mysterious, alien-looking creature–are spilling out of Canadian rocks

Say Hello to Dickinsonia, the Animal Kingdom’s Newest (and Oldest) Member

Charnia looks like a leaf or feather:

Kimberella looks like a lost earring:

Dickinsonia looks like one of those astronaut footprints on the moon:

Spriggina looks like a centipede no a trilobite no a polychaete worm no a

Glide reflection is hard to describe unless you look at pictures:

Trilobozoans look like the Manx flag or a cloverleaf roll:

Cochleatina looked like a snail:

Show transcript:

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

It’s the last week of August 2022, so let’s close out invertebrate August with a whole slew of mystery fossils, all invertebrates.

But first, we have a birthday shoutout! A humongous happy birthday to Isaac! Whatever your favorite thing is, I hope it happens on your birthday, unless your favorite thing is a kaiju attack.

We’ve talked about the Cambrian explosion before, especially in episode 69 about some of the Burgess shale animals. “Cambrian explosion” is the term for a time starting around 540 million years ago, when diverse and often bizarre-looking animals suddenly appear in the fossil record. But we haven’t talked much about what lived before the Cambrian explosion, so let’s talk specifically about the Ediacaran (eedee-ACK-eron) biota!

I was halfway through researching this episode when I remembered I’d done a Patreon episode about it in 2021. Patrons may recognize that I used part of the Patreon episode in this one. You’d think that would save me time but surprise, it did not.

The word Ediacara comes from a range of hills in South Australia, where in 1946 a geologist noticed what he thought were fossilized impressions of jellyfish in the rocks. At the time the rocks were dated to the early Cambrian period, and this was long before the Cambrian explosion was recognized as a thing at all, much less such an important thing. But since then, geologists and paleontologists have reevaluated the hills and determined that they’re much older than the Cambrian, dating to between 635 to 539 million years ago. That’s as much as 100 million years before the Cambrian. The Ediacaran period was formally designated in 2004 to mark this entire period of time, although fossils of Ediacaran animals generally start appearing about 580 million years ago.

Here’s something interesting, by the way. During the Ediacaran period, every day was only 22 hours long instead of 24, and there were about 400 days in a year instead of 365. The moon was closer to the earth too. And life on earth was still sorting out the details.

Fossils from the Ediacaran period have been discovered in other places besides Australia, including Namibia in southern Africa, Newfoundland in eastern Canada, England, northwestern Russia, and southern China. Once the first well-preserved fossils started being found, in Newfoundland in 1967, paleontologists started to really take notice, because they turned out to be extremely weird. The fossils, not the paleontologists.

Many organisms that lived during this time lived on, in, or under microbial mats on the sea floor or at the bottoms of rivers. Microbial mats are colonies of microorganisms like bacteria that grow on surfaces that are either submerged or just tend to stay damp. Microbial mats are still around today, usually growing in extreme environments like hot springs and hypersaline lakes. But 580 million years ago, they were everywhere.

One problem with the Ediacaran biota, and I should explain that biota just means all the animals and plants that live in a particular place, is that it’s not always clear if a fossil is actually an animal. Many Ediacaran fossils look sort of plant-like. At this stage, the blurry line between animals and plants was even more blurry than it is now, with the added confusion that sometimes non-organic materials can resemble fossils, and vice versa.

For instance, the fossil Charnia, named after Charnwood Forest in England where it was first discovered. In 1957, a boy named Roger, who was rock-climbing in the forest, found a fossil that looked like a leaf or feather. He took a rubbing of the fossil and showed his father, who showed it to a geologist. The year before, in 1956, a 15-year-old girl named Tina saw the same fossil and told her teacher, who said those rocks dated to before the Cambrian and no animals lived before the Cambrian, so obviously what she’d found wasn’t a fossil.

Tina’s teacher was wrong about that, of course, although he was correct that the rocks dated to before the Cambrian, specifically to about 560 million years ago. But while Charnia looks like a leaf, it’s not a plant. This was about 200 million years before plants evolved leaves, and anyway Charnia lived in water too deep for plants to survive. It anchored itself to the sea floor on one end while the rest of the body stuck up into the water, and some specimens have been found that were over two feet long, or 66 cm. Some researchers think it was a filter feeder, but we have very little evidence one way or another.

One common animal found in Australia and Russia is called Kimberella, which lived around 555 million years ago and might have been related to modern mollusks or to gastropods like slugs. It might have looked kind of like a slug, at least superficially. It grew up to 6 inches long, or 15 cm, 3 inches wide, or 7 cm, and an inch and a half high, or 4 cm, which was actually quite large for most animals that lived back then. It was shaped roughly like an oval, with one thin end that stuck out, potentially showing where its front end was, although it didn’t have a head the way we think of it today. The upper surface of its body was protected by a shell, but not the type of shell you’d find on the seashore today. This was a flexible, non-mineralized shell, basically just thick, toughened tissue with what may be mineralized nodules called sclerites embedded in it. All around its body was a frill that might have acted as a gill. The underside of Kimberella was a flat foot like that of a slug.

We know Kimberella lived on microbial mats on the sea floor, and it might have had a feeding structure similar to a radula. That’s because it’s often found associated with little scratches on its microbial mat that resemble the scratches made by a radula when a slug or related animal is feeding on a surface. The radula is a tongue-like organ studded with hard, sharp structures that the animal uses to scrape tiny food particles from a surface.

Kimberella displays bilateralism, meaning it’s the same side to side. That’s the case with a lot of modern animals, including all vertebrates and a lot of invertebrates too, like insects and arachnids. But other Ediacarans showed radically different body plans. Charnia, for instance, exhibits glide reflection, where both sides are the same as in bilateralism, but the sides aren’t exactly opposite each other. If you walk along a beach and make footprints in the sand, your trail of footprints actually demonstrates glide reflection. If you stand on the sand and jump forward with both feet together, your footprints demonstrate bilateralism since the prints are side by side. (This is confusing to describe, sorry.) Pretty much the only living animals with this body pattern are some sea pens, which get their name because they resemble old-fashioned quill pens. Many sea pens look like plants, and for a long time researchers thought Charnia might be an ancient relation to the sea pen. These days most researchers are less certain about the relationship.

A similar-looking animal that lived around the same time as Charnia was Dickinsonia. It looks sort of like a leaf too, but a more broad oval-shaped leaf instead of a long thin one like Charnia. It’s also not a leaf. Some are only a few millimeters long, but some are over 4 1/2 feet long, or 1.4 meters.

Dickinsonia may be related to modern placozoans, a simple squishy creature only about one millimeter across. It travels very slowly across the sea floor and absorbs nutrients from whatever organic materials it encounters. But we don’t know if Dickinsonia was like that or if it was something radically different. Until a few years ago a lot of paleontologists thought Dickinsonia might be some kind of early plant or algae. Then, in 2016, a graduate student discovered some Dickinsonia fossils that were so well preserved that researchers were able to identify molecular information from them. They found cholesteroids in the preserved cells, and since only animals produce cholesteroids, Dickinsonia was definitely an animal. But that’s still about all we know about it so far.

Spriggina is another animal that at first glance looks like a leaf or feather. Then it sort of resembles a trilobite, or a segmented worm, or a possible relation to Dickinsonia. It looks like all sorts of animals but doesn’t really fit with anything known. It grew up to two inches long, or 5 cm, and had what’s referred to as a head shield although we don’t know for sure if it was actually its head. The head shield might have had eyes and might have had some kind of antennae, and some fossils seem to show a round mouth in the middle of the head, but it’s hard to tell. The rest of its body was segmented in rings. What Spriggina didn’t have was legs, or at least none of the fossils found so far show any kind of legs. Some species of Spriggina show a glide reflection body plan, while others appear to show a more ordinary bilateral body plan.

Three Ediacaran animals have such a weird body plan that they’ve been placed in their own phylum, Trilobozoa, meaning three-lobed animals. They show tri-radial symmetry, meaning that they have three sections that are identical radiating out from the center. They lived on microbial mats and were only about 40 mm across at most, which is about an inch and a half. Tribrachidium was roughly round in shape although its relations looked more like tiny cloverleaf rolls. Cloverleaf rolls are made by putting three little round pieces of dough together and baking them so that the roll has three lobes, although Trilobozoans probably didn’t taste as good. Also, Trilobozoans were covered with little grooves from center to edge and had three curved ridges, one on each lobe. The ridges were originally interpreted as arms or tentacles, but they seem to have just been ridges. Researchers think the little grooves directed water over the body’s surface and the ridges acted as tiny dams that slowed the water down just enough that particles of food carried in the water would fall onto the body so that the animal could absorb the nutrients, although we don’t know how that worked.

Many other Ediacaran animals had radial symmetry like modern echinoderms and jellyfish, including the ancestors of jellyfish. Some Ediacaran animals even had shells of various kinds, and they’re generally referred to as small shelly fossils. They were rarely more than a few millimeters across at most and are sometimes found mixed in with microbial mats. Cochleatina, for instance, is less than a millimeter across and all we know about it is that it had a ribbon-like spiral shell like a really simple snail’s shell. It wasn’t a snail, though. We don’t even know if it was an animal. It might have been some kind of algae or it might have been something else. Unlike most small shelly fossils, Cochleatina survived into the Cambrian period.

We’re also not sure why most Ediacaran organisms went extinct at the beginning of the Cambrian, but it’s probable that most were outcompeted by newly evolved animals. There may also have been a change in the chemical makeup of the ocean and atmosphere that caused an extinction event of old forms and allowed the rapid expansion of new animal forms that we call the Cambrian explosion.

We can also learn a lot about what we don’t find in the Ediacaran rocks. Pre-Cambrian animals didn’t appear to burrow into the sea floor, or at least we haven’t found any burrows, just tracks on the surface. Most Ediacaran animals also didn’t have armored bodies or claws or so forth. Researchers think that predation was actually pretty rare back then, with most animals acting as passive filter feeders to gather nutrients from the water, or they ate the microbial mats. It wasn’t until the Cambrian explosion that we see evidence that some animals evolved to kill and eat other animals exclusively.

With every new Ediacaran fossil that’s found and studied, we learn more about this long-ago time when multi-cellular life was brand new.

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 283: Crocodylomorphs and Friends

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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

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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 279: Mean Piggies

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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 277: Rewilding Scotland

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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

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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 265: Penguins!

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Thanks to Page for suggesting we talk about penguins this week!

A big birthday shout-out to EllieHorseLover this week too!

Further reading:

March of the penguins (in Norway)

Rare Yellow Penguin Bewilders Scientists

Giant Waikato penguin: school kids discover new species

An ordinary king penguin with the rare “yellow” king penguin spotted in early 2021 (photo by Yves Adams, taken from article linked above):

Show transcript:

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

I was looking over the ideas list recently and noticed that Page had suggested we cover a specific bird way back in 2020! It’s about time we get to it, so thanks to Page we’re going to learn about penguins this week, including a penguin mystery.

But first, we have a birthday shout-out! Happy birthday to EllieHorseLover, whose birthday comes right before next week’s episode comes out. Have a fantastic birthday, Ellie, and I agree with you about horses. They are awesome and so are you.

Also, a quick correction from last week’s episode about Dolly the dinosaur. If you listened to episode 264 the day it came out, you heard the incorrect version, but I was able to correct it and upload the new version late that day. Many thanks to Llewelly, who pointed out that Dolly hasn’t actually been identified as a Diplodocus, just as a sauropod in the family Diplodocidae. Paleontologists are still studying the fossil and probably will be for some time. Also, I said that sauropods aren’t related to birds but that’s not the case. Sauropods share a common ancestor with birds and that’s why they both have the same kind of unusual respiratory system.

So, speaking of birds, it’s time to learn about penguins! We’ve talked about penguins twice before, but not recently at all. It’s about time we really dug into the topic.

Penguins live in the southern hemisphere, including Antarctica. The only exception is the Galapagos penguin, which we talked about in episode 99, which lives just north of the equator. Penguins are considered aquatic birds because they’re so well adapted to swimming and they spend most of their time in the ocean finding food. Instead of wings, their front limbs are flippers that they use to maneuver in the water. They’re incredibly streamlined too, with a smooth, dense coat of feathers to help keep them warm in cold water without slowing them down.

One of the ways a penguin keeps from freezing in the bitterly cold winters of Antarctica and in cold water is by a trick of anatomy that most other animals don’t have. The artery that supplies blood to the flippers crosses over the veins that return blood from the flippers deeper into the body. The arterial blood is warm since it’s been through the body’s core, but the blood that has just traveled through the flippers has lost a lot of heat. Because the veins and the arteries cross several times, the cold venal blood is warmed by the warm arterial blood where the blood vessels touch, which means the blood returning into the body’s core is warm enough that it doesn’t chill the body.

Penguins groom their feathers carefully to keep them clean and spread oil over them. The oil and the feathers’ nanostructures keep them from icing over when a penguin gets out of the water in sub-zero temperatures. The feathers are not only super-hydrophobic, meaning they repel water, their structure acts as an anti-adhesive. That means ice can’t stick to the feathers no matter how cold it is. In 2016 researchers created a nanofiber membrane that repels water and ice with the same nanostructures found in penguin feathers. It could eventually be used to ice-proof electrical wires and airplane wings.

Penguin feathers also trap a thin layer of air, which helps the penguin stay buoyant in the water and helps keep its skin warm and dry.

While a penguin is awkward on land, it’s fast and agile in the water. It mostly eats small fish, squid and other cephalopods, krill and other crustaceans, and other small animals, and it can dive deeply to find food. The emperor penguin is the deepest diver, with the deepest recorded dive being over 1,800 feet, or 565 meters. The gentoo penguin has been recorded swimming 22 mph underwater, or 36 km/hour.

Penguins are famous for being mostly black and white, but in 2010, a study of an extinct early penguin revealed that it looked much different. The fossil was found in Peru and is incredibly detailed. The flipper shape is clear, proving that even 36 million years ago penguins were already fully aquatic. Even some of the feathers are preserved, allowing researchers to reconstruct the bird’s coloration from melanosomes in the fossilized feathers. They show that instead of black and white, the extinct penguin was reddish-brown and gray. The bird was also one of the biggest penguins known, up to five feet long, or 1.5 meters.

Another species of extinct penguin was discovered in 2006 in New Zealand by a group of school children on a field trip. The New Zealand penguin lived between about 28 and 34 million years ago and while it wasn’t as big as the Peru fossil penguin, it had longer legs that made it about 4.5 feet tall, or 1.4 meters. It was described as a new species in September of 2021 and somehow I missed that one when I was researching the 2021 discoveries episode.

The smallest penguin alive today is the fairy penguin, which only grows 16 inches tall at most, or 40 cm. It lives off the southern coasts of Australia and Chile, and all around New Zealand’s coasts. It’s also called the little blue penguin because its head is gray-blue. The largest penguin is the emperor penguin, which lives in Antarctica and can grow over four feet tall, or 130 cm.

The king penguin looks like a slightly smaller version of the emperor penguin, which makes sense because they’re closely related. It can stand over 3 feet tall, or 100 cm. Its numbers are in decline due to climate change that has caused some of the small fish and squid the penguins eat to move away from the penguin’s nesting grounds. Large-scale commercial fishing has also reduced the number of fish available to penguins. As a result, the penguins have a hard time finding enough food for themselves and their babies. King penguins are protected, though, and conservation efforts are in place to stop commercial fishing near their nesting grounds. A ban on commercial fishing around Robben Island in South Africa, where the endangered African penguin nests, increased the survival of chicks by 18%, so hopefully the same will be true for the king penguin.

In early 2021, a Belgian wildlife photographer named Yves Adams was leading a group of photographers on an island where king penguins live. They spotted a group of the penguins swimming nearby when Adams noticed that one of the penguins seemed really pale. It was yellowish-white instead of black and white, although it did have the yellow markings on its head and breast that other king penguins have. It and the other penguins came ashore and Adams got lots of pictures of it. Ornithologists who have studied the pictures aren’t sure what kind of genetic anomaly has caused the penguin’s coloration, but with luck scientists will be able to find it again and take a genetic sample.

The king penguin is also the subject of a small penguin mystery, but the mystery starts with the great auk. As we talked about in episode 78, the name penguin was originally used for a bird also called the great auk or gairfowl, which lived in the northern hemisphere. It was common throughout its range until people decided to start killing them by the thousands for their feathers and meat. By 1844, the last pair of great auks were killed. The great auk was a black and white aquatic bird that looked a lot like a penguin due to convergent evolution.

The story goes that in the late 1930s people started seeing great auks on the Lofoten Islands off the coast of Norway. Since this was 70 years after the great auk officially went extinct, the reports caused a flurry of excitement.

While a small, scattered population of great auks probably did persist for years or even decades after their official extinction, once an expedition investigated the Lofoten Islands they discovered not auks but penguins. Specifically, a small group of king penguins. How did the penguins get there from their natural range in various sub-Antarctic islands on the other side of the world?

Some reports say whalers captured some penguins as pets and later released them, but it actually appears that the introduction of nine king penguins to two islands off the coast of Norway was done by the Nature Protection Society, backed by the Norwegian government, in 1936. The penguins were still there until at least 1944, with the last sighting coming from 1954.

These weren’t the only penguins released in the islands. In 1938 the Norwegian government released around 60 other penguins from various species onto the islands. The goal was to establish penguin breeding colonies in Norwegian waters in a confused attempt to claim the Antarctic for Norwegian whaling. The real mystery is why they thought that would work.

Very occasionally, a stray penguin is found in the northern hemisphere with no idea how it got there. In the past, people assumed the penguin got lost and swam the wrong way or got pushed away from its homeland by storms, but these days biologists think these lost penguins were transported by fishing boats. Sometimes a penguin will get tangled in a fishing net and hauled aboard by accident, and the fishers will untangle it and keep it as a pet for a while before setting it free. It would be better if the penguin was set free immediately so it could return to its home, but it’s better than being killed. Just ask the penguin.

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 256: Mammoths and the End of the Ice Ages

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Further reading:

Million-year-old mammoth genomes shatter record for oldest ancient DNA

Mammoth Genome Project (with pictures of cave art and ancient carvings of mammoths)

The most famous cave painting of a mammoth, from a cave in France:

Sivatherium:

Show transcript:

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

It’s the last Monday of 2021, which means the very last extinction event episode. There’ve been way more extinction events in earth’s long history than the five we’ve covered this year, and not all of the extinction events I chose to highlight were even necessarily the biggest. This one, for instance.

You may have noticed a pattern when I talk about ice age megafauna. So many animals went extinct about 11,000 years ago. That’s this week’s topic, the end-Pleistocene extinction event.

The Pleistocene is often called the ice age, or ice ages since it consisted of multiple glaciation periods separated by warmer times when the glaciers would retreat for a while. It started roughly 2.6 million years ago and is considered to have ended 11,700 years ago. Keep in mind, as always, that these dates are just a shorthand to help scientists refer to changes in earth’s history. There was no one day where the sun rose and everything had abruptly changed from one era to another. The changes took place over a long time, hundreds of thousands of years, with different parts of the world changing more quickly or slowly than others depending on local conditions.

At the beginning of the Pleistocene, the world’s continents were roughly in their present positions. Two continental plates in what is now Central America collided very slowly over millions of years, which caused the land to buckle up and magma to erupt through the earth’s crust as volcanoes. The volcanoes created islands in the Central American Seaway, a section of ocean between North and South America that connected the Atlantic and Pacific Oceans. By around 5 to 10 million years ago, the volcanoes and land continued to be pushed up, and sediment from rivers filled in between them, until finally instead of islands there was actual land that connected North and South America. That land is called the Isthmus of Panama and it allowed the great American interchange where animals from North America could cross into South America, and vice versa, but that’s a topic for another episode.

Another result of the Isthmus of Panama’s formation is that the Atlantic and Pacific Oceans were more separated. Instead of ocean currents circulating between North and South America, they were cut off and new currents formed. Ocean currents help distribute warm water to colder areas and cold water to warmer areas, which affects air and land temperatures too. Around 2.5 million years ago, the ocean current changes had changed the entire overall temperature of the earth, making it much cooler overall. That wasn’t the only cause of the ice ages, but it was a major factor.

The earth gradually became cooler and dryer, a process that had already started due to other causes and was accelerated by the ocean current changes. As the global temperature dropped, more and more water was locked up in huge glaciers called ice sheets, at first around the poles and then farther south. This meant sea levels dropped a lot. North America was connected to Asia by a stretch of grassland steppe called Beringia that had formerly been submerged.

As the temperatures dropped and the climate changed, animals and plants had to adapt. The ancestors of modern elephants had lived in Africa for millions of years, but they started migrating to other parts of the world around 3 million years ago. Because they were already big, they were good at retaining heat in their bodies and became quite successful as the climate grew cooler and cooler. They evolved long hair to stay even warmer and spread throughout much of the world, including Europe, Asia, and North America. You may know them as mammoths, which were closely related to the modern Asian elephant. The first mammoth known was the South African mammoth that lived around 5 million years ago and stood about 12 feet tall at the shoulder, or 3.7 meters.

We actually know a lot about the various species of mammoth because we have so many remains. Our own distant ancestors left cave paintings and carvings of mammoths and other animals in many parts of the world, we’ve found lots of fossilized remains, and we have lots of subfossil remains too. Because the mammoth lived so recently and sometimes in places where the climate hasn’t changed all that much in the last 10,000 years, namely very cold parts of the world with deep layers of permafrost beneath the surface, sometimes mammoth remains are found that look extremely fresh.

Before people understood extinction and related natural concepts, some people who lived in areas where dead mammoths occasionally weathered out of the permafrost thought they’d only died recently. That’s how fresh the dead animals looked. The people didn’t know what the animals were, though, and assumed that since they were only ever seen partially buried, they must be underground animals. In parts of Siberia, people thought mammoths lived underground and if they accidentally came to the surface, they died.

In February of 2021, a genetic study of mammoth DNA found in teeth was published in Nature. Nature is one of the most important scientific journals in the world and they don’t just publish any old genetic study these days, now that DNA is so much easier to sequence than it used to be. In this case, though, the DNA came from three mammoth teeth that were more than one million years old and possibly around 1.5 million years old. The teeth were found in the 1970s in different places. Before DNA was successfully found in the teeth, the oldest DNA sequenced was from a horse bone that was about 780,000 years old at the most.

Genetic material breaks down relatively quickly once an animal dies, becoming more and more fragmented as the years pass by. That’s why we don’t have any dinosaur DNA—they just lived too long ago for any usable genetic material to remain. The mammoth genetic study is a big deal since it’s pushed back scientists’ ability to sequence ancient DNA, at least of some samples. In the case of both the mammoth teeth and the ancient horse bone, the remains were preserved in permafrost that slowed the fragmentation of the DNA.

The study found that one of the teeth belonged to an early woolly mammoth and the other two were from early steppe mammoths, but it’s not as simple as it sounds. The two steppe mammoth teeth looked alike but their genetic story was very different. One had genetic markers that identified it as an ancestor of woolly mammoths–but the other didn’t. The one that didn’t is called the Krestovka sample and was found in Russia. Researchers aren’t sure yet if it’s actually a new species or subspecies, but it was obviously part of a population isolated from other steppe mammoths.

But it gets even more complicated, because Columbian mammoths from North America do show that some of their ancestors were related to the Krestovka sample–and Columbian mammoths are also related to woolly mammoths. Researchers suspect that the Columbian mammoth was a species that developed from hybrids of the Krestovka steppe mammoths and woolly mammoths. Over half a million years ago, there were enough of these hybrid mammoths that they were actually numerous enough to form their own stable species. Hybrid speciation is still a relatively new concept but as genetic studies get more sophisticated, we’re getting more evidence of it happening.

Researchers are hopeful that even older genetic samples can eventually be sequenced, but there’s a hard limit to DNA found in permafrost. That limit is 2.6 million years, which is when the permafrost began forming. And that brings us back to the ice age.

Mammoths weren’t the only animals adapted to cold conditions, of course. They weren’t even the only elephant lineage that adapted to the cold. Mastodons aren’t actually that closely related to mammoths but they are an elephant relation.

The woolly rhinoceros was about the size of living rhinoceros species but was covered in thick fur. It had a massive hump on its shoulders that was made up of fat reserves and muscle, much like modern bison. It went extinct about 10,000 years ago.

A giraffe relation, Sivatherium, lived in Africa and parts of Asia during the Pleistocene. Its neck wasn’t as long as a modern giraffe’s but it was still tall, over 7 feet tall at the shoulder, or more than 2 meters, and almost 10 feet tall including the head and neck, or 3 meters. The males had two pairs of ossicones that resembled antlers, a large pair on its head and a smaller pair over its eyes. Ossicones are bony projections usually covered with skin and hair, and modern giraffes have ossicones too.

Mammals weren’t the only megafauna, though. Mega just means big, and fauna just means animal. There were megafauna birds and reptiles too, such as the Asian ostrich. It lived throughout much of Asia and the Middle East until around 8,000 years ago and was related to the modern ostrich. The wonambi was an Australian constrictor snake, not related to the snakes living in Australia now, that could grow up to 30 feet long, or 9 meters.

So what happened to cause the extinction of all these amazing animals? Surely we know more about this extinction event than we do about older ones since it happened so recently, right?

Actually, no. Although it feels significant to us now, the end-Pleistocene extinction event actually wasn’t very big compared to the others we’ve discussed this year. A lot of ice age megafauna are still around, including bears, wolves, moose, reindeer, horses, bison, elephants, giraffes, lions, tigers, camels, kangaroos, tapirs, ostriches, condors, and lots more. Even humans are ice age megafauna since we spread throughout the world during the Pleistocene.

We do have hints of what might have caused the end-Pleistocene extinction event, and one big hint comes from what happened in Australia. Like the rest of the world, Australia’s climate was cooler and dryer during the ice ages and animals that had adapted to the cold lived throughout the continent. This included diprotodon that we talked about in episode 224, along with kangaroos, wombats, koalas, and other marsupial mammals that were bigger than the ones living today. But extinctions in Australia started a lot earlier than they did in the rest of the world, around 45,000 years ago. There’s also no corresponding extinction event among marine animals. By about 40,000 years ago almost 90% of all species of Australian megafauna had gone extinct, while smaller animals and marine animals were mostly just fine.

One specific event that happened around 45,000 years ago was the colonization of Australia by humans. Humans had visited and even lived in Australia as far back as 70,000 years ago, but by 45,000 years ago they were really spreading throughout the land. The animals of Australia had never encountered smart, fast tool-users before and didn’t know what to do except try to avoid them. Humans had weapons like spears that could kill at long range, and humans worked together to kill animals that before then had no predators due to their size. Humans also drink a lot of water because we developed in a part of Africa where water is abundant. Fresh water isn’t nearly as abundant in Australia, so humans would stake out water sources and keep other animals away.

The Australian extinctions were probably a combination of climate change, humans hunting large animals that reproduced slowly, and humans outcompeting animals for water sources. The same causes probably led to extinctions in other parts of the world, but because humans took longer to spread to continents like the Americas that are far away from Africa, those extinctions mostly took place later than in Australia. It’s also important to note that Africa showed almost no extinctions at the end of the Pleistocene. Researchers think this is because the animals of Africa evolved alongside humans and knew how to deal with us.

Natural climate change was definitely a contributing cause to the extinctions, though. Ice sheets melted, glaciers retreated, and the world warmed over the course of just a few thousand years. Animals that were well adapted to the cold had to move to places where it was still cold, but those places didn’t always have the right foods or enough food. The sea levels rose too, cutting off access to parts of the world. Beringia became covered with ocean again, for instance, where it remains today, separating Asia from North America.

Humans probably finished off the mammoths by hunting the last ones to extinction, but some populations survived much later than the 10- to 12,000 years ago commonly given as their extinction date. There were still mammoths alive in the world only 4,000 years ago and maybe only 3,700 years ago—but only on an island where humans didn’t live.

Wrangel Island is located in the Arctic Ocean near western Siberia, more than 85 miles from the nearest coast, or 140 km. It has low mountains and sea cliffs and is cold and dry most of the year, which is the kind of climate mammoths preferred.

The woolly mammoths that lived on Wrangel Island were probably cut off from the mainland when sea levels rose and flooded Beringia. They lived on for thousands of years after their mainland relations had gone extinct. Gradually the mammoths became more and more inbred, leading to genetic defects at a much higher rate than in a healthy population. Even so, the mammoths might have managed to survive even longer except for one thing. Around 1700 BCE, humans arrived on the island. Shortly afterwards, the mammoth was extinct.

Wrangel Island is a nature sanctuary these days and home to lots of animals, including polar bears, walruses, Arctic foxes, seals, reindeer, musk ox, and wolves. All of these are considered ice age megafauna, so although the mammoths are gone, other megafauna remain.

While we don’t know for sure that humans played a big part in the end-Pleistocene extinction event, we sure didn’t help. We can’t blame our ancient ancestors for their actions but we can learn from their mistakes. We’re in the middle of another extinction event right now, often called the Holocene extinction or Anthropocene extinction, directly due to our actions. Habitat loss, pollution, overhunting, and human-caused climate change are driving more species of animal and plant to extinction every year.

It can feel overwhelming, but there are lots of small things you can do to help. Just picking up trash and putting it in the waste bin or remembering to take your reusable bags to the grocery store can make a difference. No one person can fix all the world’s problems, but if everyone does a little bit to help, the big problems get smaller and more manageable. If everyone pitches in, we can make the world a cleaner, better place for animals and for people.

Happy new year! Let’s make it a great one!

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!