Episode 463: The Big Fish Episode

It’s an episode just absolutely full of fish! Thanks to Arthur, Yuzu, Jayson, Kabir, Nora, Siya, Joel, Elizabeth, Mac, Ryder, Alyx, Dean, and Riley for their suggestions this week!

Further reading:

Study uncovers mechanics of machete-like ‘tail-whipping’ in thresher sharks

Business end of a sawfish:

Giant freshwater stingray!

The frilled shark looks like an eel:

The frilled shark’s teeth:

The thresher shark and its whip-like tail [photo by Thomas Alexander – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=50280277]:

The Halmahera epaulette shark, looking a little bit like a long skinny koi fish [photo by Mark Erdmann, California Academy of Sciences, Attribution, https://commons.wikimedia.org/w/index.php?curid=30260864]:

A mudskipper, which is a fish even though it kind of looks like a weird frog [photo by Heinonlein – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=44502355]:

The red-lipped batfish wants a big kiss:

The male blue groper is very blue [photo by Andrew Harvey, some rights reserved (CC BY) – https://www.inaturalist.org/photos/62196538, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=157789928]:

The giant oarfish is very long:

Show transcript:

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

This week we have a big fish episode! I mean, it’s a big episode about a lot of different fish, not necessarily fish that are big—although some of them sure are! Thanks to Arthur, Yuzu, Jayson, Kabir, Nora, Siya, Joel, Elizabeth, Mac, Ryder, Alyx, Dean, and Riley. I told you this is a big fish episode.

Let’s jump right in with a fish suggested by Jayson, the sawfish. There are five species of sawfish alive today. The smallest can still grow over 10 feet long, or 3 meters, while the biggest species can grow over 20 feet long, or 6 meters. The largest sawfish ever reliably measured was 24 feet long, or 7.3 meters.

The sawfish lives mostly in warm, shallow ocean waters, usually where the bottom is muddy or sandy. It can also tolerate brackish and even freshwater, and will sometimes swim into rivers and live there just fine.

The sawfish is a type of ray, and rays are most closely related to sharks. Like sharks, rays have an internal skeleton made of cartilage instead of bone, but they also have bony teeth. You can definitely see the similarity between sharks and sawfish in the body shape, although the sawfish is flattened underneath, which allows it to lie on the ocean floor. There’s also another detail that helps you tell a sawfish from most sharks: the rostrum, or snout. It’s surprisingly long and studded with teeth on both sides, which makes it look like a saw.

The teeth on the sawfish’s saw are actual teeth. They’re called rostral teeth and the rostrum itself is part of the skull, not a beak or a mouth. It’s covered in skin just like the rest of the body. The sawfish’s mouth is located underneath the body quite a bit back from the rostrum’s base, and the mouth contains a lot of ordinary teeth that aren’t very sharp.

Since the sawfish has plenty of teeth in its mouth, you may be wondering how and why it also has extra teeth on both sides of its saw. It’s because the rostral teeth evolved from dermal denticles.

Dermal denticles look like scales but they’re literally teeth, they’re just not used for eating. Sharks have them too, along with some other fish. In the case of the sawfish, the rostral teeth grow much larger than an ordinary dermal denticle, and stick out sideways.

Both the rostrum and the head are packed with electroreceptors that allow the sawfish to sense tiny electrical charges that animals emit as they move. This might mean a school of fish swimming through muddy water, or it might mean a crustacean hiding in the sand. The sawfish sometimes uses its rostrum to dig prey out of the sand, but it also uses it to slash at fish or other animals. Then the sawfish can either grab the injured or dead animal with its mouth or pin it to the sea floor with its rostrum to maneuver it into its mouth. Its mouth is relatively small and it prefers to swallow its food whole, head-first, so it can only eat fish that are smaller than its mouth. That’s also why it doesn’t want to eat people. Its mouth is too small.

Yuzu wanted to learn about another shark relation, the giant freshwater stingray, which lives in rivers in southeast Asia. It’s dark gray-brown on its back and white underneath, and it has a little pointy nose at the front of its disc. It also has dermal denticles on its back.

The giant freshwater stingray has a rounded, flattened body, and it’s really big. A big female can grow over 7 feet across, or 2.2 meters. Its tail is long and thin with the largest spine of any stingray known, up to 15 inches long, or 38 cm. Its tail is so long that if you measure the giant freshwater stingray by length including its tail, instead of by width of its disc, it can be as much as 16 feet long, or about 5 meters. Some researchers think there might be individuals out there much larger than any ever measured, possibly up to 16 feet wide. The length and thinness of the tail gives the ray its other common name, the giant freshwater whipray, because its tail looks like a whip.

While we’re talking about shark relations, let’s go ahead and talk about a few actual sharks. Kabir wanted to learn about the frilled shark, which looks and acts more like an eel than a shark. A big female can grow up to 6 and a half feet long, or 2 meters. Males are a little shorter on average. The frilled shark has the same anatomy found in ancient sharks from the fossil record, dating back at least 95 million years. It’s found a body type that works for it.

The frilled shark lives on the continental shelf in many parts of the world, and while it technically lives near the sea floor, at night it migrates closer to the ocean surface to find fish, squid and other cephalopods, and other food. There are two species known, with the southern African frilled shark only discovered in 2009.

The frilled shark is dark brown or gray, and its jaws are long and contain clusters of teeth in little rows. Each tooth has three sharp points, and there are 300 teeth, so a frilled shark has 900 points in its mouth. The points are so sharp that scientists examining dead sharks have gotten cut on the teeth, which would be really embarrassing if you’re a shark expert that was bitten by a dead shark. The frilled shark can open its jaws extremely wide to swallow fish and other animals that are up to about half the size of the shark itself. It even eats other sharks.

Next, Joel wanted to learn about the thresher shark. It’s a truly big fish that can grow up to 20 feet long, or over 6 meters. It’s a fast, slender shark with a tail fin that can be as long as its body. It eats a lot of other animals, including birds and crustaceans, but it specializes in hunting fish that travel in schools, like tuna, sardines, and mackerel. It uses its incredibly long tail as a whip, slapping a fish to stun it so the shark can eat it. When it whips its tail, its body flexes so that its head points downward in the water with the tail snapping forward over it. A 2024 study determined that the thresher shark’s vertebral column is fortified to allow it to work like a catapult. The thresher shark can also use its long tail to help it leap out of the water completely, although scientists don’t know why it wants to do that.

There are three species of thresher shark known to science, but in 1995 a genetic analysis revealed the possible presence of a fourth species. Scientists think it lives in the eastern Pacific and may look similar to the bigeye thresher, enough that it gets misidentified as that species when it’s seen. The three known species of thresher shark are hard to tell apart at a distance as it is.

And for our last shark, Siya asked about the Halmahera epaulette shark. It’s light brown with darker and lighter spots, and is a slender shark that can grow a little over 2 feet long, or 68 cm. It lives around Indonesia, and it might live in other places too. We don’t know yet, because it was only discovered in 2013 and only two specimens have ever been found.

Epaulette sharks are also called walking sharks, because they use their fins to walk along the sea floor and explore crevices in rocks. Some species can even walk short distances on land to enter tidal pools and other places where they can find food. They live in warm, shallow water, usually near reefs or islands, and they eat whatever small animals they can find. There are nine species known, but there are undoubtedly more than haven’t yet been discovered by science. You might think this is strange for a shark that can walk on land, but walking sharks are nocturnal and not very big, so it’s easy to miss them when they’re out and about.

That brings us to Arthur’s suggestion, the mudskipper. The mudskipper also uses its fins to walk. Its pectoral fins are muscular and allow it to climb out of the water and onto land, climb into low branches, and even jump. Its pectoral fins look like little arms, complete with an elbow. The elbow is actually a joint between the actual fins and the radial bones, which in most fish are hidden within the body but which stick out of the mudskipper’s sides a short distance. This helps it move around on land more easily. Its pelvic fins are also shaped in such a way that they act as little suction cups on land.

The mudskipper is so good at living on land that it’s actually considered semi-aquatic. It lives in mudflats, mangrove swamps, the mouths of rivers where they empty into the ocean, and along the coast, although it prefers water that’s less salty than the ocean but more salty than ordinary freshwater. It only lives in tropical and subtropical areas because it needs high humidity to absorb oxygen through its skin and the lining of its mouth and throat.

The mudskipper is a fish, but it looks an awful lot like a frog in some ways, due to convergent evolution. It has a wide mouth and froglike eyes at the top of its head and will often float just under the water with its eyes above water, looking for insects it can catch. The largest species grows about a foot long, or 30 cm, and while it has some scales, its body is coated with a layer of mucus to help it retain moisture. It spends most of the day on land, hunting for insects and other small animals. Not only can it absorb oxygen through its skin, it keeps water in its gill chambers to keep the gills wet too. It even has a little dimple under its eye that holds water, that helps keep its eyes moist.

The mudskipper also takes a big mouthful of water with it when it climbs on land, but not to breathe. It uses the water to hunt with. When it encounters an insect or other small animal on land, it carefully rotates its mouth–yes, it can rotate its mouth, which has led to me trying to rotate my mouth, something humans can’t actually do–so that its mouth is just above the animal. Then it spits out the mouthful of water onto the insect and immediately sucks the water back into its mouth, carrying the insect with it. When it catches an animal underwater, it opens its big mouth quickly, causing suction that sucks the animal right into its mouth. It also has sharp teeth, so when an animal is in its mouth, it’s not getting out again.

Alyx, Dean, and Riley suggested we talk about the red-lipped batfish, a type of anglerfish only found around the Galapagos Islands in the Pacific Ocean. It lives on the ocean floor where the water is fairly shallow, and it grows about 8 inches long, or 20 cm. It’s usually a mottled brown, green, or grey with a white stomach, but its mouth is bright red. It looks like it’s wearing lipstick. It eats fish and other small animals, which it attracts using a lure on its head, a highly modified dorsal fin called an illicium.

The weirdest thing about the red-lipped batfish is actually its fins. It prefers to walk on the bottom of the ocean instead of swim, and it has modified pectoral fins called pseudolegs. The pseudolegs make it look a little bit like a weird frog with lipstick. Researchers think the red lips may be a way to attract potential mates, presumably ones who are hoping for a big smooch. At this rate I’m wondering if there are any fish that don’t walk on their fins.

Next, Mac wanted to learn about a fish called the payara. The problem is, there are two fish with that name, so let’s learn about them both!

The first payara is a pretty, silvery fish with a couple of small dark spots on its body. It’s found in the Amazon basin in South America and can grow at least 1 foot 8 inches long, or 51 cm. It’s sometimes kept in large aquariums, and is sometimes called the vampire tetra or the vampire fish because it has a pair of long fangs that it uses to stab other fish with before eating them. Its fangs stick up from its lower jaw, though, so if it’s a vampire fish, it’s an upside-down vampire.

As for the other payara, it’s related to the first kind and is also found in South America, but it’s even larger. It can grow a little over 3 feet long, or 3.3 meters. Its teeth are also large and sharp, including two big fangs sticking up from its lower jaw. In a big individual, its fangs may be 4 inches long, or 10 cm. This is not a fish you want to get bitten by! You are probably not in any danger of being bitten by this payara, though, unless you happen to spend a lot of your time swimming along the bottom of rivers in the Amazon.

Quite a while ago, Ryder suggested we learn about the pipe cichlid. I tried to find more about it and I think it’s actually a fish called the pike cichlid. Pike cichlids are popular freshwater aquarium fish that are native to tropical and subtropical parts of eastern South America, and there are about 45 species known so far. They’re typically quite small, with most species only growing a few inches long, or around 8 cm, although some species are more than twice that length. The pike part of their name comes from their shape, like a teeny-tiny pike, a predatory fish that can grow up to 5 feet long, or 1.5 meters. Pike and pike cichlids aren’t related, but pike cichlids are predatory. It’s just that instead of eating other fish, ducks, frogs, and even reptiles and mammals that end up in the water, the pike cichlid mostly eats insects.

Elizabeth wanted to learn about the blue groper, a fish found around Australia and nowhere else in the world. It lives around reefs and rocky areas near the coast, where it can find plenty of starfish, urchins, crustaceans, and other small animals to eat. It can grow almost six feet long, or 1.75 meters, and its teeth are peg-shaped to help it pick mollusks and other animals off of rocks before crushing them.

It’s called the blue groper because males are a beautiful blue color, while females are brown or reddish-brown and young fish are green. All young blue gropers are female, and as they grow up some change to become males while most remain females. The fish grow very slowly and can live to be at least 70 years old, so the fish don’t even reach maturity until they’re 15 or 20 years old. When a fish is around 30 or 35 years old, it will change gender again, this time becoming a male. But if the male of a group dies, the group’s dominant female will change into a male and turn blue. This is common in the family of fish that the blue groper belongs to, Labridae, also called wrasses.

Let’s finish with a suggestion from Nora, the oarfish. The giant oarfish and Russell’s oarfish can both grow at least 26 feet long, or 8 meters, and possibly much longer. Most of its length is tail, which often shows damage from being bitten. Since its organs are all close to the front of its body, and it doesn’t need its tail for swimming, if a predator takes a bite out of its tail, the fish is going to be fine. The oarfish can even detach pieces of its tail if it needs to, the same way some lizards can, to distract a potential predator. Like those lizards, the tail doesn’t grow back.

The oarfish is silvery in color with a red crest on its head and a mane-like fin down its back, although it’s actually an elongated dorsal fin. It has extremely long pelvic fins too.

The giant oarfish has a short, blunt snout and no teeth because it filters krill and other tiny animals from the water. It doesn’t have scales. Instead, its skin is soft with a delicate layer called ganoine that gives it a shimmery, almost metallic appearance. The long filaments of the crest on its head and its pelvic fins are also delicate. But although it’s long and slender like an eel, it actually swims vertically with its head pointing up and its tail down. We’re not sure why, although one theory is that this minimizes its profile to predators looking up from below. It can swim quickly straight up and down to avoid predators that mostly just swim forward.

We know so little about the oarfish, and what we know is so strange, that it’s the next best thing to a sea serpent. The first living giant oarfish was only filmed in 2001. Most oarfish are only seen when they’re dead or dying. It seems to live throughout the world’s oceans, except for the Arctic and Antarctic, and is a deep-sea fish but may migrate closer to the surface at night to find more food.

A Japanese legend says the oarfish predicts earthquakes. If an oarfish is seen near the surface or washes up on a beach, an earthquake is supposed to be imminent. That seems to be a coincidence, though.

The oarfish looks like a sea serpent, and some people think it might have given rise to some sea serpent sightings. This may or may not be the case, but it’s certainly a mysterious fish.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, corrections, or suggestions, email us at strangeanimalspodcast@gmail.com.

Thanks for listening!

Episode 462: Cryptic Coloration

Thanks to Måns, Sam, Owen and Askel for this week’s suggestions!

Further reading:

Shingleback Lizard

What controls the colour of the common mānuka stick insect?

The mossy leaf-tailed gecko has skin flaps that hide its shadow. There’s a lizard in this photo, I swear! [photo by Charles J. Sharp – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=92125100]:

A shingleback lizard, pretending it has two heads:

The beautiful wood nymph is a beautiful moth but also it looks like a bird poop:

The Indian stick insect (photo by Ryan K Perry, found on this page):

The buff tip moth mimics a broken-off stick. This person has a whole handful of them:

A cuttlefish can change colors quickly [photo by Σ64 – Own work, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=77733806]:

Show transcript:

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

This week we’re going to talk about a few types of camouflage, a suggestion by Måns, and we’ll also talk about some camouflaged animals suggested by Sam, Owen and Aksel, Dylan, and Nina.

There are lots of types of camouflage, not all of it visual in nature. Back in episode 191 we talked about some toxic moths that generate high-pitched clicks that bats hear, recognize, and avoid. Naturally, some non-toxic moths also generate the same sounds to mimic the toxic moths.

Måns specifically suggested cryptic coloration, also called crypsis. It’s a type of camouflage that allows an animal to blend into their surroundings, which can involve multiple methods.

Some animals have cryptic coloration mainly along the edges of the body, to defeat a skill many predators use called edge detection. A lot of amphibians and reptiles have patches surrounded by an outline, with dark patches having a darker outline and light patches having a lighter outline. This acts as disruptive camouflage, hiding the outline of an animal’s body as it moves around. Some animals take this camouflage even further, with a way to hide their own shadow.

This is the case with the mossy leaf-tailed gecko, which is native to the forests of eastern Madagascar. It can grow up to 8 inches long, or 20 cm, not counting its tail, and it’s nocturnal. Its tail is flat and broad, sort of shaped like a leaf, but it doesn’t disguise itself as a leaf.

The mossy leaf-tailed gecko has a complicated gray and brown pattern that looks like tree bark, and it can change its coloration a little bit to help it blend in even more. At night it’s well hidden in tree branches as it climbs around looking for insects, but in the day it needs to hide really well to avoid becoming some other animal’s snack while it’s sleeping.

It does this by finding a comfortable branch and flattening its body and tail against it so that it just looks like another part of the branch. But to make it even more hidden, it has a flap of skin along its sides that wraps even farther around the branch. Not only do these skin flaps hide its edges, it hides its shadow, since the flaps are really flat and there’s no curved edge of a lizard belly pressed against a branch that a predator might notice.

The most common kind of cryptic coloration is called countershading, and it’s so common that you might not even have noticed it although you see it almost every time you see a fish, amphibian, reptile, and many birds and mammals. Countershading is an animal that’s darker on top and lighter underneath, like a brown mouse with a white belly. It’s even found in some insects and other invertebrates.

Countershading is another way to hide a shadow. If a dolphin, for instance, was gray all over, its underside would look darker because of shadows, since sunlight shines down from the sky and makes shadows underneath the body. That would make its body shape look rounder, meaning it stands out more and a predator would notice it more easily. But most dolphins are pale gray or even white underneath. There’s still a shadow, but it’s no longer darker than the rest of the body. The lighter colored underside makes the shadow paler, and as a result, from a distance the dolphin looks almost the same shade all over, which makes it appear flat and the edges of its body harder to see. We even know that some dinosaurs were countershaded, with lighter colored bellies.

Countershading is so common in animals that it’s almost impossible to pick one example. Dylan suggested we learn about the shingleback lizard, an amazing animal found in many parts of Australia. It’s also called the stumpy-tailed lizard, the bobtail lizard, or the two-headed lizard. All three of those names refer to the animal’s tail, which is short and fat and actually looks like a second head. This is an example of automimicry, similar to animals that have markings that look like eyes. The lizard is brown with darker and lighter speckles and it sometimes has yellow spots too. Its belly is pale with dark spots. Its scales are large and overlap each other, and its eyes are tiny, like little black beads. It grows about a foot long, or 30 cm.

The shingleback lives in arid and desert areas, and its tough skin and overlapping scales help reduce water loss. It eats snails, insects, flowers, and other small animals and plants. When threatened, it will open its mouth wide and stick out its large, dark blue tongue. It is an impressively blue, impressively big tongue, and the inside of the shingleback’s mouth is bright pink, so the lizard has a chance to escape while its predator is startled and wondering if the lizard is dangerous. The shingleback can give a painful bite, although it’s not venomous.

The shingleback mates for life, and the female gives birth to two or three live young every year instead of laying eggs. In many reptiles that give birth to live young, the eggs basically remain in the mother’s body until they hatch, and then she gives birth. But in the shingleback’s case, her babies develop in placentas in a process very similar in many ways to placental mammals. The babies eat the placenta after they’re born, giving them a quick first meal, and they’re born ready to take care of themselves.

Sam suggested we talk about animals that can be confused with inanimate objects, which is a type of camouflage referred to as mimicry. Mimicry of all kinds is a really common type of camouflage, like all those harmless insects that have yellow and black stripes to mimic bees and wasps that can sting.

My favorite inanimate object mimic is a moth we talked about in episode 191, the beautiful wood nymph of eastern North America. It has a wingspan of 1.8 inches, or 4.6 cm, and it is indeed a beautiful little moth. Its front wings are mostly white with brown along the edges and a few brown and yellow spots, while the rear wings are a soft yellow-brown with a narrow brown edge. It has furry legs that are white with black tips. But when the moth folds its wings to rest, suddenly those pretty markings make it look exactly like a bird dropping. It even stretches out its front legs so they resemble a little splatter on the edge of the poop.

If you think about it, it makes sense that a tiny animal like an insect would want to resemble something common in its environment that’s also not eaten by very many other animals. For instance, a stick.

Owen and Aksel wanted to learn more about the walking stick, since it’s been a long time since we talked about it, episode 93. Walking stick insects are also called stick insects or phasmids. When I was a kid I was terrified of the whole idea of a stick insect, although I don’t know why. I think I thought one day I’d climb a tree and discover that some of those sticks were not actually part of the tree. I guess I spent a lot of time climbing trees, but I never actually saw a walking stick insect. Maybe that’s because they were so well camouflaged that I thought they were sticks!

Walking sticks live in trees and bushes, naturally, especially in warm areas, but they’re found on every continent except Antarctica. They’re long, thin insects with long, thin legs and they really do look like sticks. Some are green, some are brown or gray, and many have little patterns, projections, and ridges that make them look even more like real sticks. They’re closely related to another type of phasmid called a leaf insect, which as you may have already guessed, mimics a leaf. All phasmids eat leaves and other plant material and most are nocturnal.

Some phasmids can even change colors to help blend in with their background. The Indian stick insect, which is indeed found in southern India although it’s been introduced in many other parts of the world and is considered invasive in some places, grows up to about 4 inches long, or 10 cm. It’s usually brown, but it can change its color in response to light levels by moving pigment granules in its cuticle that absorb and scatter light. The Indian stick insect has many other ways to hide in plain sight. If it feels threatened, it will stretch out with its rear legs folded flat against its body and its front pair of legs stretched forward to make it look even longer. It will stay perfectly stiff even if someone picks it up, but if it thinks it’s in danger, it will spread its front legs to show a patch of red at the base of the legs. This can startle or frighten a potential predator long enough to let the stick insect get away.

One interesting thing about the Indian stick insect is that almost all individuals are females. Females don’t need to mate with a male to reproduce. The female’s babies are little clones of herself, and she drops an egg every so often onto the ground. It looks like a tiny seed, and ants think it’s a seed and will collect it and take it back to the nest to be stored for later. The egg is then protected until it hatches, when the larval insect leaves the ant nest and finds a tree or bush to hide in.

The buff tip moth also looks like a twig or branch when its wings are folded, but not in the same way the walking stick insect does. It looks like a broken-off branch instead. It’s a fairly large moth with a wingspan more than 2 and a half inches across, or 7 cm, and its wings are mostly gray with a rounded buff patch at the end. The end of its abdomen is buff too, so that it looks like the inside part of a tree branch, that’s paler than the bark. It lives throughout much of Europe and Asia, and different populations look slightly different because they’ve evolved to resemble the branches of different species of tree.

Let’s finish with Nina’s suggestion, about an animal that can change colors really fast to blend in with its background. That’s the cuttlefish, and Nina wanted to know how it changes colors so fast, and while we’re at it, why octopuses are so flexible.

The cuttlefish is a cephalopod, closely related to octopuses and squid, but is quite small in comparison. It has eight arms and two feeding tentacles, just like the squid, but its arms are really small in comparison to its mantle. There are over 100 species known so far, most of which are small enough to fit in the palm of your hand. But unlike the squid or the octopus, the cuttlefish has an internal structure called the cuttlebone. It’s not a bone at all but a modified shell, which is your reminder that cephalopods are mollusks and are distantly related to clams, snails, and many other animals that have shells. The cuttlebone helps the cuttlefish stay buoyant without effort, and it also incidentally makes the body a little more structured than its squid and octopus cousins.

Octopuses are flexible because they have no bones. Basically the only hard structure in an octopus is its beak. A cephalopod’s mouth is in the middle of its arms, so it’s usually hidden from view. Way back in episode 142 we talked about how octopus muscles work, so let’s revisit that briefly. In animals with bones, muscles are attached to the bones. But octopuses don’t have bones.

The octopus’s muscles are structured differently than muscles in animals with bones. Our muscles are made up of fibers that contract in one direction. Let’s say you pick up something heavy. To do so, you contract the fibers in some muscles to shorten them, which makes the bone they’re attached to move. Then, when you push a heavy door closed, you contract other muscles and at the same time you relax the muscles you used to pick up something heavy. This pulls the arm bone in the other direction.

But in the octopus, the fibers in its muscles run in three directions. When one set of fibers contracts, the other two tighten against each other and form a hard surface for the contracted fibers to move. So they’re muscles that also sort of act like bones. It’s called a muscular hydrostat, and it actually can result in muscle movements much more precise than muscle movements where a bone is involved.

So, if you combine the octopus’s strong, precise muscle movements with its general lack of hard structures, you get a very flexible animal. Basically an octopus can squish itself through extremely small openings, as long as its beak will fit through. This can make it really hard to keep an octopus in captivity, because in addition to being flexible and squishy, the octopus is also really intelligent. It can survive for short periods of time out of the water, and it can figure out how to open its enclosure and get out to explore, or just escape.

But, back to the cuttlefish, which is small and needs to hide from predators. Like other cephalopods, the cuttlefish can change color and pattern in less than a second, and can even change the texture of its skin if it wants to look bumpy like the rocks around it.

Cephalopods have specialized cells called chromatophores in their skin. A chromatophore consists of a sac filled with pigment and a nerve, and each chromatophore is surrounded by tiny muscles. When a cuttlefish wants to change colors, its nervous system activates the tiny muscles around the correct chromatophores. That is, some chromatophores contain yellow pigment, some contain red or brown. Because the color change is controlled by the nervous system and muscles, it happens incredibly quickly, in just milliseconds.

But that’s not all, because the cuttlefish also has other cells called iridophores and leucophores. Iridophores are layers of extremely thin cells that can reflect light of certain wavelengths, which results in iridescent patches of color on the skin. While the cuttlefish can control these reflections, it takes a little longer, several seconds or sometimes several minutes.

Like other cephalopods, the cuttlefish uses its ability to change color and pattern in order to hide from predators. It also uses these abilities to communicate with other cuttlefish, because it’s a social animal. It will also sometimes frighten potential predators away with a bright, sudden display of color changing.

The most amazing thing of all is that cuttlefish can’t see colors. They have no color receptors in their eyes. But they accurately change color to match their background, even though they can’t see the color, and they can even do so if it’s almost completely dark. While scientists have some theories as to how the cuttlefish manages this, we don’t yet know how they do it for sure. So it is still a mystery!

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, corrections, or suggestions, email us at strangeanimalspodcast@gmail.com.

Thanks for listening!

Episode 459: Strange Little Dolphins

Thanks to Alexandra, Jayson, and Eilee for their suggestions this week!

Further reading:

Scientists have discovered an ancient whale species. It may have looked like a mash-up of ‘a seal and a Pokémon’

The nomenclatural status of the Alula whale

Field Guide of Whales and Dolphins [1971]

The little Benguela dolphin [photo taken from this site]:

The spinner dolphin almost looks like it has racing stripes [photo by Alexander Vasenin – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=25108509]:

The Alula whale, which may or may not exist:

Show transcript:

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

This week let’s learn about some whales and dolphins, including an ancient whale and a mystery whale, all of them really small. Thanks to Alexandra, Eilee, and Jayson for their suggestions!

Let’s start with an ancient whale, suggested by Jayson. The genus Janjucetus has been known since its first species was described in 2006, after a teenage surfer in Australia discovered the fossils in the late 1990s. It grew to about 11 feet long, or 3.5 meters, and lived about 25 million years ago. So far it’s only been found around Australia. But much more recently, just a few months ago as this episode goes live, a new species was described. That’s Janjucetus dullardi, also found in Australia along the same beach where the first Janjucetus species was found, and dating to around the same time period.

We don’t know a lot about the newly described whale, since it’s only known from some teeth and partial skull. Scientists think the individual was a juvenile and estimate it was only around 6 feet long when it died, or 2.8 meters. Small as it was, it would have been a formidable hunter when it was alive. Its broad snout was shaped sort of like a shark’s and it had strong, sharp teeth and large eyes.

Because it was an early whale, it wouldn’t have looked much like the whales alive today. It might even have had tiny vestigial back legs. Its eyes were huge in proportion to its head, about the size of tennis balls, and it probably relied on its eyesight to hunt prey because it couldn’t echolocate.

Its serrated teeth and strong jaws indicate that it might have hunted large animals, but some scientists suggest it could also filter feed the same way a crabeater seal does. Modern crabeater seals have similar teeth as Janjucetus, as do a few other seals. The projections on its teeth interlock when the seal closes its mouth, so to filter feed the seal takes a big mouthful of water, closes its teeth, and uses its tongue to force water out through its teeth. Amphipods and other tiny animals get caught against the teeth and the seal swallows them.

If Janjucetus did filter feed, it probably also hunted larger animals. Otherwise its jaws wouldn’t have been so strong or its teeth so deeply rooted. But Janjucetus wasn’t related to modern toothed whales. While it wasn’t a direct ancestor of modern baleen whales, it was part of the baleen whale’s family tree. Baleen whales, also called mysticetes, have baleen plates made of keratin instead of teeth. After the whale fills its mouth with water, it closes its jaws, pushes 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’s just like the crabeater seal, but really specialized and way bigger.

Whether or not Janjucetus could and did filter feed doesn’t really matter, because the fact that it’s an ancestral relation of modern baleen whales but it had teeth helps us understand more about modern whales.

Next, Eilee wanted to learn about the Benguela [BEN-gull-uh] dolphin, also called Heaviside’s dolphin. It lives only off the southwestern coast of Africa, and it’s really small, only a little over 5 and a half feet long at the most, or 1.7 meters. It’s dark gray with white markings, with a blunt head that’s almost cone-shaped and a triangular dorsal fin.

The Benguela dolphin is named for its ecosystem. The Benguela current flows northward along the coast, bringing cold, nutrient-rich water up from the depths, which attracts lots of animals. The dolphin lives in relatively shallow water and mainly eats fish and octopuses that it finds on or near the sea floor.

The Benguela dolphin lives in social groups and sometimes hangs out with other species of dolphin. It doesn’t travel very far throughout the year, barely more than 50 miles, or 80 km. When it hunts for food, it uses very high-pitched navigation clicks that orcas can’t hear, but when it’s in safe areas, socializing without any predators around, it communicates and navigates with lower-pitched sounds. Sharks also sometimes attack it and sometimes humans will catch and eat one, but for the most part, it lives a pretty stress-free life just hanging out with its friends and eating little fish. And that’s basically all we know about this little dolphin.

Alexandra wanted to hear about the spinner dolphin, which is common in warmer waters throughout the world. It’s called the spinner dolphin because it likes to leap into the air, spinning around as it does like an American football, which is pretty spectacular. No one except the spinner dolphin is completely sure why it spins, but scientists speculate it serves more than one purpose. The activity takes a lot of energy, so it might be a way to signal to other dolphins that it’s really strong and fit. The big splash when it lands on its side may be a way to communicate with other dolphins. The action might also help dislodge parasites like remora fish that really do attach themselves to bigger, faster animals to hitch rides and incidentally steal food.

Whatever the reason, the spinner dolphin is one of the most acrobatic dolphins in the world. It not only spins, but it jumps around, flips, slaps its tail on the water, and basically acts like a kid on the first swimming pool visit of the summer. Like most dolphins and whales, it’s a social animal, hanging out with friends, family, and sometimes other dolphin species. It eats small animals like fish, squid, and crustaceans, and at least some populations are nocturnal so they can hunt animals that migrate to shallower water at night.

The spinner dolphin is actually pretty small, growing to not quite 7 feet long at most, or 2.4 meters. It’s mainly dark gray on top, lighter gray on the sides, and pale gray or white on its belly.

Let’s finish with our mystery whale or dolphin, called the Alula whale because it was sighted near the town of Alula, Somalia at some time prior to the early 1970s. In 1971 a Dutch sea captain reported that he had seen these whales on multiple occasions, in the Gulf of Aden and the Indian Ocean. But although it’s a distinctive-sounding whale or dolphin, its existence hasn’t been verified.

Captain Willem Mörzer Bruyns, whose name I have mispronounced, described the Alula whale as being similar in size and shape to the orca or pilot whale, with a tall dorsal fin and rounded forehead. It was sepia brown all over, though, except for white scars all over its body that were shaped sort of like stars. He reported seeing small groups of these whales, anywhere from 4 to 8 of them, traveling together on at least four occasions. He estimated the whales were up to 24 feet long, or 7.2 meters.

There’s quite a bit of confusion about this mystery whale spread across the internet. Some sites I looked at mentioned a book written by Mörzer Bruyns called Field Guide of Whales and Dolphins, published in 1971, but quoted a different book, A World Guide to Whales, Dolphins, and Porpoises published in 1981 by Donald S. Heintzelman.

Let me quote the relevant paragraphs from the 1971 book, the original:

“At first encounter a school of 4 approached the ship head on and seeing the dorsal fins the author thought they were [orcas]. When they passed the ship at a distance of less than 50 yards just under the surface in the flat calm, clear sea, it was obvious that this was a different species. … These dolphins were seen in the area during crossings in April, May, June and September, usually swimming just under the surface with the dorsal fin above the water. One duty officer reported he observed them chasing a school of smaller dolphins, who tried to escape. There is, however, a possibility that both species were chasing the same prey.”

If you go to Wikipedia to read about the Alula whale, as of mid-November 2025, it states that the dorsal fin was about 6 and a half feet tall, or 2 meters. But Mörzer Bruyns reported that the dorsal fin was 2 feet tall, or about 60 cm. That’s an important difference. Orcas, AKA killer whales even though they’re actually big dolphins, are distinctively patterned with black and white, and a male orca can have a dorsal fin up to 6 feet tall, or 1.8 meters, while a female’s is typically less than half that height. The pilot whale is also a dolphin, despite its name, but it has a relatively small dorsal fin and is black, dark gray, or sometimes brown. Some researchers suggest that Mörzer Bruyns misidentified pilot whales as something mysterious, but the details he provided don’t really match up.

There are a lot of little-known whales alive today, some only discovered in the last few decades. It’s possible that the Alula whale really is a very rare small whale or dolphin. It’s not clear from his report, but it sounds like Mörzer Bruyns saw the whales on several occasions in the same year. If so, maybe the Alula whale doesn’t actually live in that part of the ocean most of the time, and Mörzer Bruyns saw the same small group several times that just happened to have traveled to the Indian Ocean that year. Maybe no one else has seen them because they’re all living in some remote part of the ocean where humans seldom travel. Hopefully someone will spot one soon.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 458: The Tasmanian Tiger and Friends

Thanks to Viki, Erin, Weller, and Stella for their suggestions this week!

Further reading:

Tasmanian tiger pups found to be extraordinary similar to wolf pups

The thylacine could open its jaws really wide:

A sugar glider, gliding [photo from this page]:

A happy quokka and a happy person:

A swimming platypus:

Show transcript:

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

This week we’re going to learn about some marsupial mammals suggested by Erin, Weller, and Stella, and a bonus non-marsupial from Australia suggested by Viki.

Marsupials are mammals that give birth to babies that aren’t fully formed yet, and the babies then finish developing in the mother’s pouch. Not all female marsupials actually have a pouch, although most do. Marsupials are extremely common in Australia, but they’re also found in other places around the world.

Let’s start with Weller’s suggestion, the Tasmanian tiger. We’ve talked about it before, but not recently. We talked about it in our very first episode, in fact! Despite its name, it isn’t related to the tiger at all. Tigers are placental mammals, and the Tasmanian tiger is a marsupial. It’s also called the thylacine to make things less confusing.

The thylacine was declared extinct after the last known individual died in captivity in 1936, but sightings have continued ever since. It’s not likely that a population is still around these days, but the thylacine is such a great animal that people hold out hope that it has survived and will one day be rediscovered.

It got the name Tasmanian tiger because when European colonizers arrived in Tasmania, they saw a striped animal the size of a big dog, about two feet high at the shoulder, or 61 cm, and over six feet long if you included the long tail, or 1.8 meters. It was yellowish-brown with black stripes on the back half of its body and down its tail, with a doglike head and rounded ears.

The thylacine was a nocturnal marsupial native to mainland Australia and the Australian island of Tasmania, but around 4,000 years ago, climate change caused more and longer droughts in eastern Australia and the thylacine population there went extinct. By 3,000 years ago, all the mainland thylacines had gone extinct, leaving just the Tasmanian population. The Tasmanian thylacines underwent a population crash around the same time that the mainland Australia populations went extinct—but the Tasmanian population had recovered and was actually increasing when Europeans showed up and started shooting them.

The thylacine mostly ate small animals like ducks, water rats, and bandicoots. Its skull was very similar in shape to the wolf, which it wasn’t related to at all, but its muzzle was longer and its jaws were comparatively much weaker. Its jaws could open incredibly wide, which usually indicates an animal that attacks prey much larger than it is, but studies of the thylacine’s jaws and teeth show that they weren’t strong enough for the stresses of attacking large animals.

Next, Stella wanted to learn about the sugar glider, and I was surprised that we haven’t talked about it before. It’s a nocturnal marsupial native to the forests of New Guinea and parts of Australia, with various subspecies kept as exotic pets in some parts of the world. It’s called a glider because of the animal’s ability to glide. It has a flap of skin between its front and back legs, called a patagium, and when it stretches its legs out, the patagia tighten and act as a parachute. This is similar to other gliding animals, like the flying squirrel.

The sugar glider resembles a rodent, but it isn’t. It’s actually a type of possum. It lives in trees and has a partially prehensile tail that helps it climb around more easily, and of course it can glide from tree to tree. It’s an omnivore that eats insects, spiders, and other small animals, along with plant material, mainly sap. It will gnaw little holes in a tree to get at the sap or gum that oozes out. It will also eat fruit, nectar, pollen, and seeds, but most of the time it prefers to hang around flowers and wait for insects to approach. Then it grabs and eats the insect without having to chase it.

The sugar glider is gray with black and white markings, big eyes that allow it to see well in darkness, rounded ears, and a really long, thick, furry tail. It’s a social animal that lives in family groups in small territories. Both males and females help take care of the joeys when they’re out of the mother’s pouch, mainly by helping them stay warm when it’s cold.

Our last marsupial of this episode is Erin’s suggestion, the quokka. It’s about the size of a domestic cat, related to wallabies and kangaroos. It’s shaped roughly like a chonky little wallaby but with a smaller tail and with rounded ears, and it’s grey-brown in color.

The quokka is considered incredibly cute because of the way its muzzle and mouth are shaped, which makes it look like it’s smiling. If you take a picture of a quokka’s face, it looks like it has a happy smile and that, of course, makes the people who look at it happy too.

This has caused some problems, unfortunately. People who want to take selfies with a quokka sometimes forget that they’re wild animals. While quokkas aren’t very aggressive and are curious animals who aren’t usually afraid of people, they can and will bite when frightened. Touching a quokka or giving it food or drink is strictly prohibited, since it’s a protected animal.

The quokka is most active at night. It sleeps during most of the day, usually hidden in a type of prickly plant that helps keep predators from bothering it. It gets most of its water needs from the plants it eats, and while it mostly hops around like a teensy kangaroo, it can also climb trees.

Let’s finish with our non-marsupial animal. Viki wanted to learn about the platypus, which we haven’t really talked about since way back in episode 45. It’s native to Australia and is very weird-looking, so it’s easy to think it’s another marsupial, but the platypus is even weirder than that. It’s not a marsupial and it’s not a placental mammal. Instead, it’s an extremely rare third type of mammal called a monotreme.

There are only two kinds of monotremes alive today, the echidna and the platypus. Monotremes retain a lot of traits that are considered primitive in mammals. Instead of giving birth to live babies, a monotreme mother lays eggs. The eggs have soft, leathery shells, but when they hatch, the babies look like marsupial newborns.

The platypus is sometimes called the duck-billed platypus, because its snout does kind of look like a duck’s bill, but instead of being hard, the snout is soft and rubbery, and it’s packed with electroreceptors that allow the platypus to sense the tiny electrical fields generated by muscle contractions in its prey. I bet that was not what you expected from what looks like a small beaver with a duck bill!

The platypus grows not quite two feet long, or 50 cm, and has short, dense, brown fur. It spends a lot of its time in the water, and has a flattened tail that acts as a rudder when it swims, along with its hind feet. It propels itself through the water with its front feet, which are large and have webbed toes. It lives in eastern Australia along rivers and streams, and digs a short burrow in the riverbank to sleep in. The female digs a deeper burrow before she lays her eggs, and she makes them a nest out of leaves.

Baby platypuses are called puggles, and while the mother doesn’t have a pouch, she keeps her babies warm by tucking them against her tummy with her tail. Monotremes don’t have teats, but they do produce milk from what are called milk patches. The puggles lick the milk up. Until scientists figured out that monotremes have these milk patches, in 1824, they thought monotremes weren’t mammals at all but something more closely related to reptiles.

Monotremes were much more common throughout the world until about 60 to 70 million years ago, when marsupials started outcompeting them. Marsupials don’t spend much time in water, though, because if they did their joeys would drown. The platypus and echidna both survived to the present day because they’re adapted for the water. The platypus mainly navigates in the water using its electrolocation abilities, and eats worms, fish, insects, crustaceans, and anything else it can catch.

It’s easy to think, “Oh, that mammal is so primitive, it must not have evolved much since the common ancestor of mammals, birds, and reptiles was alive 315 million years ago,” but of course that’s not the case. It’s just that the monotremes that survived did just fine with the basic structures they evolved a long time ago, and they’re still going strong today.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 457: Parrots!

Thanks to Fleur, Yuzu, and Richard from NC for their suggestions this week!

Further reading:

World’s rarest parrot, extinct in wild, hatches at zoo

Kakapo recovery

This Parrot Stood 3 Feet Tall and Ruled the Roost in New Zealand Forests 19 Million Years Ago

The magnificent palm cockatoo:

The gigantic kakapo:

Show transcript:

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

This week we have a bird episode, specifically some interesting parrots. Thanks to Fleur, Yuzu, and Richard from NC for their suggestions!

Parrots are intelligent, social birds that are mostly found in tropical and subtropical parts of the world, but not always. Most parrots eat plant material exclusively, especially seeds, nuts, and fruit, but some species will eat insects and other small animals when they get the chance. Most parrots are brightly colored, but again, not always. And, unfortunately, most parrot species are endangered to some degree due to habitat loss, hunting for their feathers and for the pet trade, and introduced predators like cats and rats.

All parrots have a curved beak that the bird uses to open nuts and seeds, but which also acts as a tool or even a third foot when it’s climbing around in trees. All parrots have strong clawed feet that they also use to climb around and perch in trees, and to handle food and tools.

Let’s start with Yuzu’s suggestions, the cockatoo and the parakeet. A parakeet is a small parrot, but it’s a term that refers to a lot of various types of small parrots. This includes an extinct bird called the Carolina parakeet.

It was small parrot that was common throughout a big part of the United States. It had a yellow and orange head and a green body with some yellow markings, and was about the size of a mourning dove or a passenger pigeon. Its story of extinction mirrors that of the passenger pigeon in many ways. The Carolina parakeet lived in forests and swamps in big, noisy flocks and ate fruit and seeds, but when European settlers moved in, turning forests into farmland and shooting birds that were considered pests, its numbers started to decline. In addition, the bird was frequently captured for sale in the pet trade and hunted for its feathers, which were used to decorate hats.

By 1860 the Carolina parakeet was rare anywhere except the swamps of central Florida, and by 1904 it was extinct in the wild. The last captive bird died in the Cincinnati Zoo in 1918, which was not only the same zoo where the last passenger pigeon died in 1914, it was the same cage. It was declared extinct in 1939.

The parakeet Yuzu is probably referencing is the budgie, or budgerigar. It’s the one that’s extremely common as a pet, and it’s native to Australia. In the wild it’s green and yellow with black markings, but the domestic version, which has been bred in captivity since the 1850s, can be all sorts of colors and patterns, including various shades of blue, yellow all over, white, and piebald, meaning the bird has patches of white on its body.

The budgie can learn to repeat words and various sounds, especially if it’s a young bird. I had two parakeets as a kid, named Dandelion and Sky so you can guess their colors, and neither learned to talk although I really tried to teach them. Some birds just aren’t interested in mimicry, while others won’t stop, especially if they get attention when they speak.

In the wild, budgies live in flocks that will travel long distances to find food and water. The birds mostly eat grass seeds, especially spinifex, but will sometimes eat wheat, especially in areas where farmland has destroyed much of their wild food. They’re social birds that are sometimes called lovebirds, although that’s the name of a different type of bird too, because they will preen and feed their mates.

Like many birds, the parakeet can see ultraviolet light, and their feathers glow in UV light. This makes them even more attractive to potential mates, as if the parakeet wasn’t beautiful enough to start with.

Yuzu also asked about the cockatoo. There are 21 species of cockatoo, also native to Australia and other nearby places, including Indonesia and New Guinea. It’s much larger than the budgie and most species have a crest of some kind. It lives in flocks and eats various types of plant material, including flowers and roots, but it will also eat insects. The cockatoo isn’t as brightly colored as many parrots, and is usually black, white, or gray, often with patches of color on the crest, cheeks, or tail.

The pink cockatoo is white with pale salmon pink markings on the body, and brighter pink and yellow on its crest. The sulphur-crested cockatoo is white with pale yellow on the undersides of the wings and tail, and a bright yellow crest. We talked about the palm cockatoo in episode 23 because not only does it look like it should be a drummer of the Muppet Animal variety, since it’s black with red cheeks and a big messy crest, it does actually use sticks and nuts to drum against tree branches, to attract a mate.

Richard from NC suggested we learn about Spix’s macaw, also called the blue macaw, because it’s considered one of the world’s rarest parrots. In fact, it was declared extinct in the wild in 2019. It only survives at all because of intensive conservation efforts, including a captive breeding program spread over multiple zoos.

The blue macaw is native to one small part of Brazil in South America, although it used to be much more common several hundred years ago. It’s blue with a gray-blue head. It’s such a beautiful parrot that it was driven to extinction by people trapping the birds to sell as pets, even though that had been outlawed by Brazil, although its numbers had been falling for centuries due to habitat loss. It relied on a particular species of tree called the tree of gold, because its flowers are bright yellow. The blue macaw nested in these trees, and its seedpods were one of its main foods. As groves made up of the tree of gold were chopped down to make way for farmland and towns, the bird became more and more rare.

Luckily, even though the blue macaw doesn’t breed very quickly in captivity, by 2022 there were enough healthy young birds to release twenty into the wild. Just a few weeks ago as this episode goes live, another egg has hatched in captivity in a bird conservation center in Belgium, after the previous hundred eggs were infertile and never hatched.

Next, Fleur wanted to learn more about the kakapo, a flightless, nocturnal parrot that lives only in New Zealand. We talked about it in episode 313, but it’s definitely time to revisit it.

The kakapo is the largest living parrot. It has green feathers with speckled markings, blue-gray feet, and discs of feathers around its eyes that make its face look a little like an owl’s face. That’s why it’s sometimes called the owl parrot. Males are almost twice the size of females on average. It can grow over two feet long, or 64 cm, and can weigh as much as 9 lbs, or about 4 kg. That’s way too heavy for it to fly, but its legs are short but strong and it will jog for long distances to find food. It can also climb really well, right up into the very tops of trees. It uses its strong legs and its large curved bill to climb. Then, to get down from the treetop more efficiently, the kakapo will spread its wings and parachute down, although its wings aren’t big enough or strong enough for it to actually fly. A big heavy male sort of falls in a controlled plummet while a small female will land more gracefully.

The kakapo evolved on New Zealand where it had almost no predators. A few types of eagle hunted it during the day, which is why it evolved to be mostly nocturnal. Its only real predator at night was one type of owl. As a result, the kakapo was one of the most common birds throughout New Zealand when humans arrived.

But by the end of the 19th century, the kakapo was becoming increasingly rare everywhere. By 1970, scientists worried that the kakapo was already extinct. Fortunately, a few of the birds survived in remote areas. Several islands were chosen as refuges, and all the kakapos scientists could find were relocated to the islands, 65 birds in total. While the kakapo is doing a lot better now than it has in decades, it’s still critically endangered. The current population is 237 individuals according to New Zealand’s Department of Conservation.

The kakapo may be the largest living parrot, but it’s not the largest parrot that ever lived. That would be the giant parrot. It’s known only from a few fossils dated to between 16 and 19 million years ago, but from those fossils scientists estimate that the giant parrot grew around 3 feet tall, or almost a meter, and possibly weighed almost twice what the kakapo weighs. It’s the largest parrot that ever lived as far as we know, and it was probably related to the kakapo.

We don’t know a lot about the giant parrot because only two fossils have been found, both of them leg bones and probably from the same individual. They bones are so big that scientists initially thought they belonged to an eagle. Hopefully soon more fossils will come to light so we can learn more about the giant parrot. For all we know, those leg bones belonged to a young parrot that wasn’t fully grown yet. Maybe the adults were even bigger than we think!

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 452: Rare Wallabies and Two Hoofed Beasts

Thanks to Brody, Oz, and Sam for their suggestions this week!

Further reading:

Chasing gold

Two spectacled hare-wallabies hanging out under a spinifex bush [picture from this site]:

A regular swamp wallaby [photo by jjron – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=4022233]:

The glorious golden swamp wallaby [photo by Jack Evershed, taken from the first article linked above]:

The takin can also be golden:

The gaur is so incredibly big! It’s so big, honestly, it’s just ridiculous:

Show transcript:

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

This week we have suggestions from Oz, Sam, and Brody, with some interesting mammals!

Let’s start with Brody’s suggestion, the wallaby! It’s been a while since we talked about the wallaby, which is an adorable marsupial closely related to the kangaroo. It’s native to Australia and New Guinea, part of the family Macropodidae.

One thing everyone knows about kangaroos, which is also true for wallabies, is that they hop instead of running. Their hind legs are extremely strong with big feet, and in fact the word Macropodidae means big feet. The animal hops by leaning forward and jumping, with its big hind feet leaving the ground at about the same time, and landing at the same time too before it bounces again. Its big tail helps it balance.

We talked about the wallaby last in episode 390, so let’s learn about some species of wallaby that we didn’t talk about then. For example, the spectacled hare-wallaby. It’s a small species that’s common in northern Australia and parts of Papua New Guinea. It’s active at night and is mostly solitary, so unless you’re wandering around at night you might not have seen one. It’s called the spectacled hare-wallaby because it has orange-colored fur around its eyes so that it looks sort of like it’s wearing glasses. The rest of its fur is brown, gray, and golden. Its ears are small and its tail and hind legs are very long, with short little front legs. It’s very cute.

The spectacled hare-wallaby prefers sandy or stony areas, like dunes and shrubland, where it can find lots of plants to eat but can easily hop away if it spots a predator. It’s smaller than a domestic cat, but it can travel incredibly fast when it wants to.

If you live along the eastern part of Australia, you might have seen the swamp wallaby, also called the black wallaby because it’s mostly dark gray or gray-brown in color, often with a white tip to the tail. It’s stocky and much larger than the spectacled hare-wallaby, almost three feet tall, or 85 cm, when it’s sitting up. It doesn’t just live in swamps but also likes forests and other areas with lots of places to hide. Unlike the spectacled hare-wallaby, it’s not that fast and can’t always outrun potential predators, but it’s good at hiding because its fur is so dark.

Most wallabies are grazers, meaning they mainly eat grass, but the swamp wallaby is a browser. Instead of having grinding teeth to break down grass, its teeth are sharper for cutting through plant material like bushes, shrubs, and ferns. The swamp wallaby will even use its front legs to pull branches into reach so it can eat the leaves.

Wallabies are marsupials, meaning the babies are born extremely early by our standards, crawl into the mother’s pouch and clamp onto a teat, and continue to develop in the pouch. Wallabies usually only have one baby at a time, but the mother swamp wallaby has two babies in its pouch almost all its adult life. The swamp wallaby has two uteruses, and a few days before the first baby is ready to be born, the female comes into estrus again, meaning she’s ready to mate. By the time her first baby is born, she’s already pregnant with her second baby. When the second baby is born, the first baby is old enough that’s it doesn’t spend all the time in the pouch—but by then, she’s already pregnant with her third baby. By the time the third baby is born, the first baby is grown up and on its own, the second baby is old enough that it isn’t in the pouch all the time, and—you guessed it—the mother is already pregnant with baby four. It sounds exhausting, but it works well for the swamp wallaby.

As I mentioned, the swamp wallaby is also called the black wallaby, but there’s a rare color variation that’s called a golden swamp wallaby. It’s still a swamp wallaby but its fur is golden yellow and it has a white face. The coloration is due to a mutation in coat color, but golden swamp wallabies seem to be perfectly safe in the few areas where they’re found, so it doesn’t seem to be a detriment. Some scientists suspect the color morph is helpful in open forests with sandier soil, which is exactly where the golden swamp wallabies are found.

Speaking of golden animals, let’s talk next about the takin, suggested by Sam. We talked about the golden takin back in episode 218, which is a subspecies of takin. The takin is closely related to sheep and mountain goats, but it looks more like a small musk ox.

The takin lives in the eastern Himalaya Mountains, and is a strong, stocky animal with a lot of adaptations to intense cold. It has a thick coat that grows even thicker in winter, with a soft, dense undercoat to trap heat next to the body. It also has large sinus cavities that warm the air it breathes before it reaches the lungs, which means it has a big snoot. Its skin is oily, which acts as a water repellent during rain and snowstorms. In spring it migrates to high elevations, but when winter starts it migrates back down to lower elevations where it’s not quite as cold.

It will eat just about any plant material it can reach, including tree bark, tough evergreen leaves, and bamboo. It sometimes shares the same bamboo forests where pandas live. It will even sometimes push over small trees so it can eat the leaves. It visits salt licks regularly, and some researchers think it needs the minerals available at salt licks to help neutralize the toxins found in many plants it eats.

Both male and female takins have horns, which grow sideways and back from the forehead in a crescent and can be almost three feet long, or 90 cm. It can stand over four feet tall at its humped shoulder, or around 1.4 m. Its fur is mainly golden-brown with gray and white patches.

A full-grown takin is big enough and strong enough that it doesn’t have many predators. If a bear or wolf threatens it, it can run fast if it needs to or hide in dense underbrush. But it’s just a little tiny baby compared to our last animal this week, suggested by Oz: the gaur. [pronounced gow-ur]

We’ve only mentioned the gaur once on the podcast, way back in episode 58, when I mispronounced it “gar.” It’s the largest living bovid, also called the Indian bison, although it doesn’t just live in India. It’s native to southeast Asia, but it’s increasingly rare due to habitat loss and poaching, even though it’s a protected animal.

The gaur looks kind of like a domestic cow, but much larger. It’s dark brown and its lower legs are white, as is its nose. It has a fairly short tail and long curving horns that are mostly pale but black at the tips, and its ears are large. Females are lighter in color than males and calves are a pale sandy-brown.

How big is the gaur? A big bull can grow over seven feet high at the shoulder, or 2.2 meters, and it’s even a bit taller if you measure it at the muscular hump just behind the shoulder. It’s an incredibly heavy animal too, with only elephants, rhinos, hippos, and giraffes being heavier than a big bull. A bull can weigh over 3,300 lbs, or 1,500 kg. It’s so massive and muscular that bulls in particular look like they just got back from the gym and they’re flexing to show off.

The gaur is a bovid, but it doesn’t eat very much grass. Like the swamp wallaby, it’s a browser. It’s mainly found in forests, where it eats leaves, flowers, fruit, and even the bark of some trees, and it lives in herds of about a dozen animals each led by a wise old cow.

Almost the only predator that can kill a full-grown gaur is a tiger, and naturally the gaur does not like tigers at all as a result. If a herd spots a tiger, they form a ring around the calves to protect them, and if the tiger tries to approach, the adult gaurs attack and try to drive the tiger away. Sometimes the gaurs can even kill the tiger. At night the adult gaurs make a ring around the calves this same way, so that if a tiger or other predator approaches in the night, the adults are ready to defend their babies as soon as they wake up. Personally, if I were a tiger I think I wouldn’t bother trying to kill a gaur.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 447: So Many Legs!

Thanks to Mila for suggesting one of our topics today!

Further reading:

The mystery of the ‘missing’ giant millipede

Never-before-seen head of prehistoric, car-size ‘millipede’ solves evolutionary mystery

A centipede compared to a millipede:

Show transcript:

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

Let’s finish invertebrate August this year with two arthropods. One is a suggestion from Mila and the other is a scientific mystery that was solved by a recent discovery, at least partially.

Mila suggested we learn about centipedes, and the last time we talked about those animals was in episode 100. That’s because centipedes are supposed to have 100 legs.

But do centipedes actually have 100 legs? They don’t. Different species of centipede have different numbers of legs, from only 30 to something like 300. Like other arthropods, the centipede has to molt its exoskeleton to grow larger. When it does, some species grow more segments and legs. Others hatch with all the segments and legs they’ll ever have.

A centipede’s body is flattened and made up of segments, a different number of segments depending on the centipede’s species, but at least 15. Each segment has a pair of legs except for the last two, which have no legs. The first segment’s legs project forward and end in sharp claws with venom glands. These legs are called forcipules, and they actually look like pincers. No other animal has forcipules, only centipedes. The centipede uses its forcipules to capture and hold prey, and to defend itself from potential predators. A centipede pinch can be painful but not dangerous unless you’re also allergic to bees, in which case you might have an allergic reaction to a big centipede’s venom. Small centipedes can’t pinch hard enough to break a human’s skin.

A centipede’s last pair of legs points backwards and sometimes look like tail stingers, but they’re just modified legs that act as sensory antennae. Each pair of a centipede’s legs is a little longer than the pair in front of it, which helps keep the legs from bumping into each other when the centipede walks.

The centipede lives throughout the world, even in the Arctic and in deserts, but it needs a moist environment so it won’t dry out. It likes rotten wood, leaf litter, soil, especially soil under stones, and basements. Some centipedes have no eyes at all, many have eyes that can only sense light and dark, and some have relatively sophisticated compound eyes. Most centipedes are nocturnal.

The largest centipedes alive today belong to the genus Scolopendra. This genus includes the Amazonian giant centipede, which can grow over a foot long, or 30 cm. It’s reddish or black with yellow bands on the legs, and lives in parts of South America and the Caribbean. It eats insects, spiders–including tarantulas, frogs and other amphibians, small snakes and lizards, birds, and small mammals like mice. It’s even been known to catch bats in midair by hanging down from cave ceilings and grabbing the bat as it flies by.

Some people think that the Amazonian giant centipede is the longest in the world, but this isn’t actually the case. Its close relation, the Galapagos centipede, can grow 17 inches long, or 43 cm, and is black with red legs.

But if you think that’s big, wait until you hear about the other animal we’re discussing today. It’s called Arthropleura and it lived in what is now Europe and North America between about 344 and 292 million years ago.

Before we talk about it, though, we need to learn a little about the millipede. Millipedes are related to centipedes and share a lot of physical characteristics, like a segmented body and a lot of legs. The word millipede means one thousand feet, but millipedes can have anywhere from 36 to 1,306 legs. That is a lot of legs. It’s probably too many legs. The millipede with 1,306 legs is Eumillipes persephone, found in western Australia and only described in 2021. It lives deep underground in forested areas, where it probably eats fungus that grows on tree roots. It’s long and thin with short legs and no eyes. It’s only about 1 mm in diameter, but can grow nearly 4 inches long, or almost 10 cm.

Millipedes mostly eat decaying plant material and are generally chunkier-looking than centipedes. They have two pairs of legs per segment instead of just one, with the legs attached on the underside of the segment instead of on the sides. A millipede usually has short, strong antennae that it uses to poke around in soil and decaying leaves. It can’t pinch, sting, or bite, although some species can secrete a toxic liquid that also smells terrible. Mostly if it feels threatened, a millipede will curl up and hope the potential predator will leave it alone.

The biggest millipede alive today is probably the giant African millipede, which can grow over 13 inches long, or almost 34 cm, but because millipedes are common throughout the world and are often hard for scientists to find, there may very well be much larger millipedes out there that we just don’t know about.

As an example, in 1897 scientists discovered a new species of giant millipede in Madagascar and named it Spirostreptus sculptus. One specimen found was almost 11 inches long, or over 27 cm. But after that, no scientist saw the millipede again—until 2023, when a scientific expedition looking for lost species rediscovered it, along with 20 other species of animal. It turns out that the millipede isn’t even uncommon in the area, so the local people probably knew all about it.

But Arthropleura was way bigger than any millipede or centipede alive today. It could grow at least 8 ½ feet long, or 2.6 meters, and possibly longer. It probably weighed over 100 lbs, or 45 kg. We have plenty of fossilized specimens, but not one of them has an intact head. Then scientists discovered two beautifully preserved juvenile specimens in France, and CT scans in 2024 revealed that both specimens had nearly complete heads.

The big question about Arthropleura was whether it was more closely related to millipedes or centipedes, or if it was something very different. Without a head to study, no one could answer that question with any confidence, although a lot of scientists had definite opinions one way or another. Studies of the head scans determined that Arthropleura was indeed more closely related to modern millipedes—but naturally, since it lived so long ago, it also had a lot of traits more common in centipedes today. It also had something not found in either animal, eyes on little stalks.

There are still lots of mysteries surrounding Arthropleura. For instance, what did it eat? Because of its size, scientists initially thought it might be a predator. Now that we know it was more closely related to the millipede than the centipede, scientists think it might have eaten like a millipede too. That would mean it mostly ate decaying vegetation, but we don’t know for sure. We also don’t know if it could swim or not. We have a lot of Arthropleura tracks that seem to be made along the water’s edge, so some scientists hypothesize that it could swim or at least spent part of its time in the water. Other scientists point out that Arthropleura didn’t have gills or any other way to absorb oxygen while in the water, so it was more likely to be fully terrestrial. The first set of scientists sometimes comes back and argues that we don’t actually know how Arthropleura breathed or even why it was able to grow so large, and maybe it really did have gills. A third group of scientists then has to come in and say, hey, everyone calm down, maybe the next specimen we find will show evidence of both lungs and gills, and it spent part of its time on land and part in shallow water, so there’s no need to argue. And then they all go for pizza and remember that they really love arthropods, and isn’t Arthropleura the coolest arthropod of all?

At least, I think that’s how it works among scientists. And Arthropleura is really cool.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 446: Termites

Thanks to Yonatan and Eilee for this week’s suggestion!

Further reading:

Replanted rainforests may benefit from termite transplants

A vast 4,000-year-old spatial pattern of termite mounds

A family of termites has been traversing the world’s oceans for millions of years

Worker termites [photo from this site]:

Show transcript:

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

This week we have a topic I’ve been wanting to cover for a while, suggested by both Yonatan and Eilee. It’s the termite episode!

We talk a lot about animals that eat termites, and in many cases termite-eating animals also eat ants. I’ve always assumed that termites and ants are closely related, but they’re not. Termites are actually closely related to cockroaches, which are both in the order Blattodea, but it’s been 150 million years since they shared a common ancestor. They share another trait too, in that no one wants either insect infesting their house.

Like most cockroach species, though, most termite species don’t want anything to do with humans. They live in the wild, not in your house, and they’re incredibly common throughout most of the world. That’s why so many animals eat termites almost exclusively. There are just so many termites to eat!

There are around 3,000 species of termite and about a third of them live in Africa, with another 400 or so in South America, 400 or so in Asia, and 400 or so in Australia. The rest live in other parts of the world, but they need warm weather to survive so they’re not very common in cold areas like northern Europe.

A termite colony consists of a queen, soldiers, and workers, which sounds very similar to ants, but there are some major differences. Worker termites take care of the nest and babies, find and process food so the other termites can eat it, and store the processed food. They also take care of the queen. Unlike ants and bees, worker termites aren’t only female and aren’t always sterile. Soldiers are bigger and stronger than workers, with much bigger heads and jaws so they can fight off potential predators. In some species, the soldiers have such big jaws that they can’t actually eat without help. Worker termites feed them. Finally, the queen is the largest individual in the colony, usually considerably larger than workers, but unlike queen bees and ants, she has a mate who stays with her throughout her life, called a king. Some termite queens can live to be as much as 50 years old, and she and the king spend almost their entire lives underground in a nesting chamber.

The larger the colony, the more likely it is that the colony has more than one queen. The main queen is usually the one that started the colony along with her king, and when it was new they did all the work—taking care of the eggs and babies, foraging for food, and building the nest itself. As the first workers grew up, they took on more of those tasks, including expanding the nest.

Workers are small and their bodies have little to no pigment, so that they appear white. Some people call them white ants, but of course they’re not ants. Workers have to stay in a humid environment like the nest or their bodies dry out. Workers and soldiers don’t have eyes, although they can probably sense light and dark, and instead they navigate using their antennae, which can sense humidity and vibrations, and chemoreceptors that sense pheromones released by other termites.

Termites have another caste that’s not as common, usually referred to as reproductives. These are future kings and queens, and they’re larger and stronger than workers. They also have eyes and wings. When outside conditions are right, usually when the weather is warm and humid, the reproductive termites leave the nest and fly away. Males and females pair off and search for a new nesting site to start their own colony.

Termites mainly eat dead plant material, including plant material that most other animals can’t digest. A termite’s gut contains microbes that are found nowhere else in the world, which allow the termite to digest cellulose found in plants, especially wood. Baby termites aren’t born with these microbes, but they gain them from worker termites when the babies are fed or groomed.

In some areas termites will eat the wood used to build houses, which is why people don’t like them, but termites are actually important to the ecosystems where they live, recycling nutrients and helping break down fallen trees so other plants can grow. They also host nitrogen-fixing bacteria, which are important to plant life.

A recent study in Australia determined that termites are really important for rainforest health. In some parts of Australia, conservation groups have started planting rainforest trees to restore deforested areas. Decomposers like termites are slower to populate these areas, with one site that was studied 12 years after planting showing limited termite activity. That means it takes longer for fallen branches, logs, and stumps to decay, which means it takes longer for the nutrients in those items and others to be available for other plants to use.

The problem seems to be that the new forests don’t have very many dead trees yet, so the termites don’t have a lot to eat. The team is considering bringing in fallen logs from more established forests so the termites have food and can establish colonies more easily.

Some species of termite in Africa, Australia, and South America build mounds, and those mounds can be huge. A mound is built above ground out of soil and termite dung, held together with termite saliva. It’s full of tunnels and shafts that allow the termites to move around inside and which bring air into the main part of the nest, which is mostly below ground. Different species build differently-shaped mounds, including some that are completely round.

Some termite mounds can be twice the height of a tall person, and extremely big around. The biggest measured had a diameter of almost 100 feet around, or 30 meters. But in at least one place on earth, in northeastern Brazil, there’s a network of interconnected termite mounds that is as big as Great Britain.

The complex consists of about 200 million mounds, each of them about 8 feet tall, or 2.5 meters, and about 30 feet across, or 9 meters. They’re just huge piles of soil excavated from underground, and tests have determined that the mounds range in age from 690 years old to at least 3,820 years old and are connected by tunnels–but the nests under the mounds are still in use!

Not all termite species build mounds or even live underground. A group called drywood termites live in wood and usually have much smaller colonies than other termites. They probably split off from other termites about 100 million years ago, and a 2022 genetic study determined that they probably originated in South America. But drywood termites have spread to many other parts of the world, and scientists think it’s because their homes float. They estimate that over the last 50 million years, drywood termites have actually floated across entire oceans at least 40 times. When their floating log homes washed ashore, the termites colonized the new land and adapted to local conditions.

A lot of people worry that termites will damage their homes, but in many parts of the world, people eat termites. The termites are fried or roasted until they’re nicely crunchy, and they’re supposed to have a nut-like flavor. They’re also high in protein and important fats. So the next time you worry about your house, you can shout at any potential termites that if they’re around, you might just eat them as a snack.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 442: Trees and Megafauna

Further reading:

The Trees That Miss the Mammoths

The disappearance of mastodons still threatens the native forests of South America

Study reveals ancient link between mammoth dung and pumpkin pie

A mammoth, probably about to eat something:

The Osage orange fruit looks like a little green brain:

Show transcript:

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

Way back at the end of 2017, I found an article called “The Trees That Miss the Mammoths,” and made a Patreon episode about it. In episode 320, about elephants, which released in March of 2023, I cited a similar article connecting mammoths and other plants. Now there’s even more evidence that extinct megafauna and living plants are connected, so let’s have a full episode all about it.

Let’s start with the Kentucky coffeetree, which currently only survives in cultivation and in wetlands in parts of North America. It grows up to 70 feet high, or 21 meters, and produces leathery seed pods so tough that most animals literally can’t chew through them to get to the seeds. Its seed coating is so thick that water can’t penetrate it unless it’s been abraded considerably. Researchers are pretty sure the seed pods were eaten by mastodons and mammoths. Once the seeds traveled through a mammoth’s digestive system, they were nicely abraded and ready to sprout in a pile of dung.

There are five species of coffeetree, and the Kentucky coffeetree is the only one found in North America. The others are native to Asia, but a close relation grows in parts of Africa. It has similar tough seeds, which are eaten and spread by elephants.

The African forest elephant is incredibly important as a seed disperser. At least 14 species of tree need the elephant to eat their fruit in order for the seeds to sprout at all. If the forest elephant goes extinct, the trees will too.

When the North American mammoths went extinct, something similar happened. Mammoths and other megafauna co-evolved with many plants and trees to disperse their seeds, and in return the animals got to eat some yummy fruit. But when the mammoths went extinct, many plant seeds couldn’t germinate since there were no mammoths to eat the fruit and poop out the seeds. Some of these plants survive but have declined severely, like the Osage orange.

The Osage orange grows about 50 or 60 feet tall, or 15 to 18 meters, and produces big yellowish-green fruits that look like round greenish brains. Although it’s related to the mulberry, you wouldn’t be able to guess that from the fruit. The fruit drops from the tree and usually just sits there and rots. Some animals will eat it, especially cattle, but it’s not highly sought after by anything. Not anymore. In 1804, when the tree was first described by Europeans, it only grew in a few small areas in and near Texas. The tree mostly survives today because the plant can clone itself by sending up fresh sprouts from old roots.

But 10,000 years ago, the tree grew throughout North America, as far north as Ontario, Canada, and there were seven different species instead of just the one we have today. 10,000 years ago is about the time that much of the megafauna of North and South America went extinct, including mammoths, mastodons, giant ground sloths, elephant-like animals called gomphotheres, camels, and many, many others.

The osage orange tree’s thorns are too widely spaced to deter deer, but would have made a mammoth think twice before grabbing at the branches with its trunk. The thorns also grow much higher than deer can browse. Trees that bear thorns generally don’t grow them in the upper branches. There’s no point in wasting energy growing thorns where nothing is going to eat the leaves anyway. If there are thorns beyond reach of existing browsers, the tree must have evolved when something with a taller reach liked to eat its leaves.

The term “evolutionary anachronism” is used to describe aspects of a plant, like the Osage orange’s thorns and fruit, that evolved due to pressures of animals that are now extinct. Scientists have observed evolutionary anachronism plants throughout the world. For instance, the lady apple tree, which grows in northern Australia and parts of New Guinea. It can grow up to 66 feet tall, or 20 meters, and produces an edible red fruit with a single large seed. It’s a common tree these days, probably because the Aboriginal people ate the fruit, but before that, a bird called genyornis was probably the main seed disperser of the lady apple.

In episode 217 we talked about the genyornis, a flightless Australian bird that went extinct around 50,000 years ago but possibly more recently. It grew around 7 feet tall, or over 2 meters, and recent studies suggest it ate a lot of water plants. It would have probably eaten the lady apple fruit whenever it could, most likely swallowing the fruits whole and pooping the big seeds out later.

Way back in episode 19 we talked about a tree on the island of Mauritius that relied on the dodo’s digestive system to abrade its seeds so they could sprout. It turns out that study was flawed and the seeds don’t need to be abraded to sprout. They just need an animal to eat the flesh off the seed, either by just eating the fruit and leaving the seed behind, or by swallowing the entire fruit and pooping the seed out later, and that could have been done by any number of animals. The dodo probably did eat the fruits, but so did a lot of other animals that have also gone extinct on Mauritius.

In June of 2025, a study was published showing that the gomphothere Notiomastodon, which lived in South America until about 10,000 years ago, definitely ate fruit. Notiomastodon was an elephant relation that could probably grow almost ten feet tall, or 3 meters. It probably lived in family groups like modern elephants and probably looked a lot like a modern elephant, at least if you’re not an elephant expert or an elephant yourself. The 2025 study examined a lot of notiomastodon teeth, and it discovered evidence that the animals ate a lot of fruit. This means it would have been an important seed disperser, just like the African forest elephant that we talked about earlier.

Another plant that nearly went extinct after the mammoth did is a surprising one. Wild ancestors of modern North American squash plants relied on mammoths to disperse their seeds and create the type of habitat where the plants thrived. Mammoths probably behaved a lot like modern elephants, pulling down tree limbs to eat and sometimes pushing entire trees over. This disturbed land is what wild squash plants loved, and if you’ve ever prepared a pumpkin or squash you’ll know that it’s full of seeds. The wild ancestors of these modern cultivated plants didn’t have delicious fruits, though, at least not to human taste buds. The fruit contained toxins that made them bitter, which kept small animals from eating them. Small animals would chew up the seeds instead of swallowing them whole, which is not what the plants needed. But mammoths weren’t bothered by the toxins and in fact probably couldn’t even taste the bitterness. They thought these wild squash were delicious and they ate a lot of them.

After the mammoth went extinct, the wild squash lost its main seed disperser. As forests grew thicker after mammoths weren’t around to keep the trees open, the squash also lost a lot of its preferred habitat. The main reason why we have pumpkins and summer squash is because of our ancient ancestors. They bred for squash that weren’t bitter, and they planted them and cared for the plants. So even though the main cause of the mammoth’s extinction was probably overhunting by ancient humans, at least we got pumpkin pies out of the whole situation. However, I personally would prefer to have both pumpkin pie and mammoths.

You can find Strange Animals Podcast at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us for as little as one dollar a month and get monthly bonus episodes.

Thanks for listening!

Episode 439: The Missing Echidna

Thanks to Cara for suggesting we talk about the long-beaked echidna this week!

Further reading:

Found at last: bizarre, egg-laying mammal finally rediscovered after 60 years

A short-beaked echidna:

The rediscovered Attenborough’s long-beaked echidna:

Show transcript:

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

This week we’re going to learn about an animal suggested by Cara, the echidna, also called the spiny anteater. It’s a type of mammal, but it’s very different from almost all the mammals alive today. We talked about the echidna briefly in episode 45, but this week we’re going to learn more about it, especially one that was thought to be extinct but was recently rediscovered.

Cara specifically suggested we learn about the long-beaked echidna, which lives only in New Guinea. The short-beaked echidna lives in New Guinea and Australia. The names short and long beaked make it sound like the echidna is a bird, but the beak is actually just a snout. It just looks beak-like from a distance and is covered with tough skin, sort of like the platypus’s snout is sometimes called a duck-bill.

In June and July of 2023, an expedition made up of scientists and local experts from various parts of Indonesia, as well as from the University of Oxford in England, discovered and rediscovered a lot of small animals in the Cyclops Mountains. They even discovered an entire cave system that no one but some local people had known about, and they discovered it when one of the expedition members stepped on a mossy spot in the forest and fell straight through down into the cave. But one animal they were really hoping to see hadn’t made an appearance and they worried it was actually extinct. That one was Attenborough’s long-beaked echidna, a type of mammal known as a monotreme.

There are three big groups of mammals. The biggest is the placental mammal group, which includes humans, dogs, cats, mice, bats, horses, whales, giraffes, and so on. A female placental mammal grows her babies inside her body in the uterus, each baby wrapped in a fluid-filled sac called a placenta. Placental mammals are pretty well developed when they’re born.

The second type is the marsupial mammal group, which includes possums, kangaroos, koalas, wombats, sugar gliders, and so on. A female marsupial has two uteruses, and while her babies initially grow inside her, they’re born very early. A baby marsupial, called a joey, is just a little pink squidge about the size of a bean that’s not anywhere near done growing, but it’s not completely helpless. It has relatively well developed front legs so it can crawl up its mother’s fur and find a teat. Some species of marsupial have a pouch around its teats, like possums and kangaroos, but other species don’t. Once the baby finds a teat, it clamps on and stays there for weeks or months while it continues to grow.

The third and rarest type of mammal these days is the monotreme group, and monotremes lay eggs. But their eggs aren’t like bird eggs, they’re more like reptile eggs, with a soft, leathery shell. The female monotreme keeps her eggs inside her body until it’s almost time for them to hatch. The babies are small squidge beans like marsupial newborns, and I’m delighted to report that they’re called puggles. There are only two monotremes left alive in the world today, the platypus and the echidna. The echidna has a pouch and after a mother echidna lays her single egg, she tucks it in the pouch.

Monotremes show a number of physical traits that are considered primitive. Some of the traits, like the bones that make up their shoulders and the placement of their legs, are shared with reptiles but not found in most modern mammals. Other traits are shared with birds. The word monotreme means “one opening,” and that opening, called a cloaca, is used for reproductive and excretory systems instead of those systems using separate openings.

It wasn’t until 1824 that scientists figured out that monotreme moms produce milk. They don’t have teats, so the puggles lick the milk up from what are known as milk patches. Before then a lot of scientists argued that monotremes weren’t mammals at all and should either be classified with the reptiles or as their own class, the prototheria.

It’s easy to think, “Oh, that mammal is so primitive, it must not have evolved much since the common ancestor of mammals, birds, and reptiles was alive 315 million years ago,” but of course that’s not the case. It’s just that the monotremes that survived did just fine with the basic structures they evolved a long time ago. There were no evolutionary pressures to develop different shoulder bones or stop laying eggs. Other structures have evolved considerably.

Monotremes aren’t closely related to any of the other mammals alive today, either marsupial or placental mammals. The last shared ancestor lived at least 163 million years ago and possibly much earlier, maybe even 220 million years ago. The first dinosaurs lived around 230 million years ago, so we are talking a very long time ago.

The echidna is relatively closely related to the platypus and its ancestors probably looked and acted a lot like a platypus, including being largely aquatic. The echidna is adapted to life on land, even though it can swim quite well. It looks superficially like a big hedgehog since it’s covered in spines as well as hair, and if it feels threatened it will curl up into a ball like a hedgehog with its spines sticking out. It’s also a strong digger and will often dig a shallow hole very quickly when threatened, so that a potential predator encounters basically a bunch of spines sticking up out of the dirt. But unlike a hedgehog, which is usually small enough to fit in an adult human’s hand, the echidna can grow over 20 inches long, or 52 cm, and a big male can weigh as much as 13 lbs, or 6 kg.

The echidna has a long, skinny snout with a pair of nostrils at the end. The snout is bare of fur and the echidna pokes it into the ground and leaf litter to find the worms and other small invertebrates it eats. Not only does it have a good sense of smell to locate food, its snout also contains electroreceptors that allow it to sense the tiny muscle movements of its prey. The short-beaked echidna mostly eats termites and ants, while the long-beaked echidna mostly eats earthworms. The echidna doesn’t have teeth and its mouth is tiny, but it has a long sticky tongue to lick up the animals it eats. The long-beaked echidna’s tongue has tiny spines on it, sort of like a cat’s tongue has tiny spines that help it groom its fur, but the spines on the echidna’s tongue help it stab worms and insect larvae and drag them into its mouth.

Attenborough’s long-beaked echidna is a subspecies that was only discovered by scientists in 1961. It’s only known from a single specimen, and it hadn’t been seen since. In 2007 a scientific expedition found signs that an echidna was still living in the Cyclops Mountains, namely nose-pokes in the dirt where an echidna had been looking for food, but despite lots of searching for the animal, no one had seen it. Since the echidna is nocturnal and spends most of the day sleeping in its burrow, it’s hard to spot even under the best conditions.

The 2023 expedition used over 80 trail cameras to try and find the echidna. The trail cams were set up for four weeks and not a single one recorded a single echidna—until the very last day, and even then it was almost the very last video on the memory card. It’s just a short little video of an echidna just walking along on its way to do echidna stuff, but it made a big difference for the scientists.

Now that we know that Attenborough’s long-beaked echidna isn’t extinct, scientists can work with local people to help protect it and its habitat.

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