Episode 295: The Peregrine Falcon



Thanks to Nikita for this week’s suggestion that we learn all about the peregrine falcon!

I’ll be at the Next Chapter Book Fair in Dalton, Georgia on October 1, 2022! Come say hi!

Further listening:

Crossover episode with Arcane Carolinas from ConCarolinas 2022!

Further reading:

Falcons see prey at speed of Formula 1 car

A peregrine falcon in flight:

Baby peregrine falcons. Look at those giant peets! [photos by Robin Duska, taken from this site]

Show transcript:

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

This week we have a suggestion from Nikita, who wants to learn about the peregrine falcon! The peregrine falcon is the fastest animal known, and I thought about trying to talk very fast for this episode, but I decided I make enough mistakes just talking normally.

A quick note before we start. On Saturday, October 1, 2022, I’ll be at the Next Chapter Book Fair and Convention in Dalton, Georgia. If you happen to be in the area, stop by and say hi! I’ll be selling books and I think I’m on a panel too. That’s the last event I have planned for the year and I’m not sure if I’ll be selling books at conventions next year. It’s fun, but it’s also a lot of work. Whatever copies of the Beyond Bigfoot & Nessie book that don’t sell next week, I can offer for sale directly from me. If you want a signed copy of a slightly banged-up paperback that’s been to a lot of conventions, email me and we can work out a price with shipping.

Speaking of conventions, back in June I had a fantastic time at ConCarolinas, and one of the things I did was join the guys from Arcane Carolinas to record an episode of their excellent podcast. Well, they’ve just released that episode and it’s fantastic! I’ll put a link in the show notes in case you don’t already listen to their podcast.

Now, let’s learn about the peregrine falcon!

The peregrine falcon lives throughout the world, with as many as 19 subspecies, although experts disagree about a few of those. It’s about the size of a crow, with females being much bigger than males. Different subspecies have different patterns, but in general the peregrine falcon is dark above and pale below with a darker barred pattern. It has bright yellow around its eyes, and the base of its hooked bill and its feet are yellow.

The peregrine mates for life, and reuses the same nesting site every year. Some populations of peregrine migrate long distances, and sometimes the male will stay year-round near the nesting site while the female migrates. Either way, at the beginning of the breeding season, which is usually around the end of winter, the pair performs courtship flights where the male will pass food to the female while they’re both flying. Sometimes the female turns over to fly upside-down to take food from her mate.

The male typically prepares several potential nesting sites, and the female chooses which one she likes best to lay her eggs. The peregrine doesn’t build a nest, though, just kicks at the dirt to make what’s called a scrape. It’s just a shallow depression in the dirt. The female lays 2 to 5 eggs that hatch in about a month into fuzzy white babies with gigantic talons. Both parents help incubate the eggs and both feed the babies after they hatch.

The peregrine especially likes open areas with cliffs for its nest, and as far as it’s concerned, skyscrapers are just a type of cliff. It’s surprisingly common in cities as a result, not to mention that cities are home to another bird, the pigeon, that the peregrine loves to eat. The peregrine mostly eats birds, especially pigeons, gulls, ducks, and various songbirds, but it will also eat bats and sometimes small animals like squirrels and rats. It mostly hunts at dawn and dusk, but it will hunt at night too and sometimes during the day.

Even though the peregrine isn’t very big compared to many birds of prey like eagles, owls, and hawks, it is an astounding hunter. It has strong feet equipped with sharp talons to grab prey, and its hooked beak is notched to help it bite through the spine of a bird it’s caught to kill it quickly.

But the main reason the peregrine is such an effective hunter is how fast it can fly. It’s pretty fast while just cruising around looking for prey, flying about 30 miles per hour, or 48 km/hour. If it spots a bird it wants to eat, it can easily more than double its speed to chase it. But that’s not all.

The peregrine’s signature move is the stoop. This is a high-speed dive from a height, and the falcon hits its prey with feet extended but clenched into a fist. Stoop speeds have been recorded and are as high as 238 miles per hour, or 383 km/hour. This is the speed of a Formula One race car! So getting hit by a stooping falcon would be like being punched by a small feathery car. BOOM! That’s the end for you.

While the peregrine mostly eats medium-sized birds, it’s been documented to kill birds as large as a sandhill crane or a great horned owl by stooping. During the stoop, the peregrine changes its body shape for maximum aerodynamics, and high-resolution photos taken of a falcon flying in a wind tunnel show that certain feathers pop up in rows to guide air over the body.

If you were riding in a race car going that fast, everything around you would look like a blur. That’s because our eyes and our brains can only capture and process images so fast. But the peregrine falcon can see just fine at those speeds, because its eyes and brain have evolved to capture and process images extremely quickly. The only birds studied with similar visual processing are flycatchers, little songbirds that chase insects to eat. Insects are fast so flycatchers are fast, but the peregrine falcon catches and eats flycatchers.

The peregrine’s speed of visual processing has a side effect when birds are kept in captivity. If the lights in their enclosure flicker at all, the birds will get sick. That’s because what may be only a barely perceptible flicker to us is like a constant strobe light for the peregrine!

The peregrine has been kept as a hunting bird for thousands of years. It’s not domesticated, but young birds are relatively easy to tame and it can be trained to return to the falconer after catching its prey. Peregrines used to be captured from the wild by falconers, and if you’ve read the book My Side of the Mountain by Jean Craighead George, this is one of the things the boy in the book does. That book was published in 1959, though, and around this time the peregrine falcon began to decline in numbers worldwide due to DDT use.

We’ve talked about DDT recently, in episode 277 about rewilding Scotland. DDT is a pesticide that was developed in the 1950s and used extensively to kill insects on crops and gardens. But DDT doesn’t just do its job and evaporate. It stays in the environment and ends up in the bodies of animals, including people. It’s especially bad for birds of prey, and it causes their eggshells to become so thin and weak that the eggs break when the mother tries to keep them warm. The peregrine falcon was one bird that was especially badly affected, especially in North America and parts of Europe, where it almost went extinct. It was placed on the endangered species list and protected, but it wasn’t until scientists realized that DDT was the cause, and DDT use was banned in most parts of the world, that the peregrine’s numbers stopped dropping.

Falconers played a big part in helping the peregrine falcon recover from nearly going extinct. Falconers mostly care deeply about their birds and know how to take care of them. While the peregrine was on the endangered species list, falconers stopped taking birds from the wild and instead bred already captive birds. Then, once DDT was banned in most places, falconers helped with the reintroduction of peregrines into the wild. The peregrine was removed from the U.S. endangered species list in 1999 and from the Canadian list in 2017. But conservationists worldwide still monitor the peregrine falcon to make sure it continues to do well in the wild.

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

Thanks for listening!


Episode 294: Updates 5 and a New Zealand Parrot!



It’s our fifth updates and corrections episode, with some fun information about a New Zealand parrot, suggested by Pranav! Thanks also to Llewelly, Zachary, Nicholas, and Simon who sent in corrections.

Further reading:

Vitiligo

Tyrannosaurus remains hint at three possible distinct species

Study refutes claim that T. rex was three separate species

The reign of the dinosaurs ended in spring

Impact crater may be dinosaur killer’s baby cousin

California mice eat monarch butterflies

‘Hobbit’ human story gets a twist, thanks to thousands of rat bones

Playground aims to distract mischievous kea

The kea showing off the bright colors under its wings:

A kea jungle gym set up to stop the birds from moving traffic cones around for fun:

Show transcript:

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

This is our fifth annual updates episode, where I catch us up on new studies published about various animals we’ve talked about before. This is mostly just whatever happens to catch my eye and isn’t comprehensive by any means. Also, because things have been so busy for me the last few weeks, I decided to just go with what I’d already finished and not try to add more.

We’ll start as usual with corrections, then do some updates, then learn about a parrot from New Zealand, which was a suggestion from Pranav. This part of the episode started as a Patreon episode from 2019, so patrons, I promise your October bonus episode will be brand new and interesting and in-depth!

First, both Llewelly and Zachary pointed out that there are lions living in Asia, not just Africa. It’s called the Asiatic lion and these days, it only lives in a few small areas in India. It’s a protected animal but even though their numbers are increasing, there are probably still no more than 700 Asiatic lions living in the wild.

Next, Nicholas points out that vitiligo isn’t a genetic condition, it’s an autoimmune disorder that can be caused by a number of different diseases and conditions. You still can’t catch it from other people, though. We talked about vitiligo briefly in episode 241, about squirrels. Nicholas included a link, which I’ll put in the show notes for anyone who’s interested in learning more.

For our final correction, Simon questioned whether there really are only six living species of macaw known. This was polite of him, since I was completely wrong about this. In fact, there are six genera of macaws and lots of species, although how many species there are exactly depends on who you ask. Since this mistake made it into the Beyond Bigfoot & Nessie book, I am very irritated at myself, but thank you to Simon for helping me clear this up.

Let’s start our updates with the animal who gets an update every single time, Tyrannosaurus rex. A study published in February 2022 examined the fossilized remains of 37 T. rexes and suggested that there may actually be three distinct species of T. rex instead of just one. The study focused specifically on differences in teeth and leg bones that don’t seem to have anything to do with the individual’s age when it died or whether it was male or female.

However, in July 2022, another study found that all the T. rexes found so far do indeed belong to the same species. This is how science works, because new information is always being discovered and that means we have to reassess the things we thought we knew.

In other dinosaur news, in episode 240 we talked about the last day of the dinosaurs. Results of a study released in February 2022 suggest that the asteroid struck in early spring in the northern hemisphere. The asteroid hit the earth so hard that it rocked the entire continental plate that it struck, which caused massive waves unlike any other waves, since all the water above the continental plate was pushed upwards at once. This pushed all the sediment lying quietly on the bottom of the ocean up into the water, so much of it at once that it actually buried a lot of fish alive. The same thing happened in lakes and every other body of water. The fossil site we talked about in episode 240 is still being studied, the one that appears to date to literally the day of the asteroid impact, and preserved soft tissues in some of the fish have been discovered. Careful analysis of the fish show evidence that they all died in early spring. Researchers suggest that the time of year may have been especially bad for many dinosaurs, who were probably just starting to lay eggs and have babies.

In even more recent last-day-of-the-dinosaurs news, in August 2022 a study was released about a newly discovered crater off the coast of West Africa. Researchers are pretty sure it was from an asteroid impact, although much smaller than the big one that hit what is now Mexico and led to the extinction of all non-avian dinosaurs. They’re also not completely certain when it formed, since it’s deep under the sea floor these days and was only discovered when scientists were examining seismic survey data of the sea floor. But it does seem to have formed about 66 million years ago, and another crater found in Ukraine is also about the same age. In other words, there may have been more than one asteroid that hit earth at the same time, either because a bigger asteroid broke into pieces as it entered earth’s atmosphere, or because smaller asteroids were orbiting the bigger one.

We’ve talked about the monarch butterfly several times, especially in episode 203. The monarch is a beautiful orange and black butterfly that migrates from the United States and Canada into central Mexico for the winter, where it gathers in huge groups. The monarch butterfly caterpillar primarily eats the milkweed plant, which contains toxins that the caterpillar stores in its body. Those toxins remain in the body even after the caterpillar has transformed into a butterfly, meaning the butterflies are toxic too. Birds and other animals learn to recognize the bright orange and black pattern of the butterfly and avoid eating it, because it tastes bad and makes them sick.

But a study from December 2021 determined that one animal does eat monarch butterflies, and a whole lot of them. Many species of mouse that live where monarch butterflies spend the winter, in a few spots in Mexico and California, will eat the butterflies, especially ones that fall to the ground either by accident or because they’re unhealthy and weak. The mice show resistance to the butterfly’s toxins.

Research into the small hominin remains on the island of Flores is ongoing, and the most recent findings shed some light on what might have happened about 60,000 years ago. The so-called Hobbit fossils have all been found at Liang Bua, a giant cave, but lots of other fossils have been found at the same site. A whole lot of those are from various species of rodent, especially rats, ranging in size from mouse-sized to ordinary rat-sized to giant rat sized, over two feet long including the tail, or about 75 cm.

Because we know a lot about the rats that lived on Flores, and in some cases still live there, we can infer a lot about what the area around Liang Bua was like over the centuries. Until about 60,000 years ago, most of the rat remains found were of medium-sized species that like open habitats. That means the area around Liang Bua was probably pretty open. But after about 60,000 years ago, there’s a big shift in what kind of rodents appear in the fossil record. More rats of smaller size moved in, ones that were adapted for life in forests, while the medium-sized rats moved out. That corresponds with other animals disappearing from the fossil record in and around the cave, including a species of Komodo dragon and a subspecies of Stegodon, an elephant relation that exhibited island dwarfism and was about the size of a cow. The Flores little people remains also vanish from the cave during this time, until by 50,000 years ago there are no signs of them.

But that doesn’t mean that H. floresiensis went extinct at that time. Researchers now think that as the land around the cave became more heavily forested, the Flores little people moved to other parts of the island that were more open. We don’t know where yet, and as a result we don’t know when exactly they went extinct. They might even have left the island completely. One neighboring island is Sulawesi, and researchers have found small stone tools on that island that are very similar to those made by H. floresiensis.

Modern humans probably arrived on the island of Flores about 46,000 years ago, and it’s possible that when they did, their small-statured cousins were still around.

We’ll finish with Pranav’s suggestion, a New Zealand parrot called the kea!

The kea is a type of parrot, but it doesn’t look much like a parrot at first glance. Parrots usually have brightly colored feathers but the kea appears more drab initially. It’s olive green with black-laced feathers, but it has bright orange feathers under its wings that show when it flies and the tips of its wings are blue. It’s a big, heavy bird with a wingspan more than three feet across, or one meter, and it has a big hooked beak like other parrots. It lives in the mountains of New Zealand’s South Island, the only parrot that lives in such a cold environment.

The kea is an omnivore but it mostly eats plants and insects. It will eat roadkill, small animals like rabbits, chicks of other species of bird, and trash. For over a century there were rumors that the kea would attack sheep, which led to the New Zealand government paying a bounty for dead keas that wasn’t lifted until 1970. By the time the bounty ended, there were only around 5,000 keas left, and even then the bird wasn’t fully protected until 1986.

So does the kea kill sheep or was that just an excuse to kill birds? Actually, the kea does attack sheep, or at least some keas do. Most of the attacks aren’t fatal, but we definitely know it happens because someone got it on video in 1992.

The keas land on the sheep’s back and pull out hunks of wool, which exposes and injures the skin underneath. Then they use their sharp beaks to dig into the wound and eat the fat from the living sheep. This can result in the sheep dying from infection and shock, naturally, so it’s no wonder sheep farmers disliked the kea. But the sheep is not an animal native to New Zealand while the kea is, plus the kea primarily eats plants—and sheep destroy the plants the kea eats, especially the ones high in vegetable lipids that provide the same high energy food that sheep fat does.

Besides, there’s some tantalizing evidence that the kea used to do the same thing to the moa, a huge flightless bird that lived in New Zealand until it went extinct after humans arrived. Moa bones dating to 4,000 years ago and found in a swamp along with lots of other well-preserved bones show markings on the pelvis that may be from kea beaks.

Like other parrots, the kea is remarkably intelligent and known for its tool use. It’s also infamous for its curiosity and willingness to disassemble things, including cars. I found an article about the kea in New Zealand Geographic that has some awesome stories about the bird, like this one that I’ll quote.

“In September 1983, the Old Pompolona Hut on the Milford Track was destroyed by flood when the pent-up Clinton River broke through its winter avalanche dam. The walking track season was only six weeks away. Planners, builders and helicopter crews worked night and day to complete a new hut complex before the first walkers arrived.

“The local clan of kea took a keen interest in all this frantic activity after a cold and quiet winter. Just what were these people up to? One bird, for whom building materials seemed to hold a particular attraction, began stealing nails. So persistent was the bird’s thievery that an exasperated carpenter chased it (in vain) over the roof of the new main hut. While his back was turned, another kea stole his packet of roll-your-owns, shredding tobacco and papers to the raucous approval of spectator kea perched in nearby trees.

“Weeks later, after the new hut had been completed, the purloined nails were discovered. They had been neatly laid in the gutters of an outbuilding’s iron roof, sorted according to size.”

The kea’s intelligence, tool use, and problem-solving abilities line up with those in corvids like crows and ravens. Studies show that corvids are more successful figuring out tasks that require them to make pecking motions in one way or another while parrots, including the kea, are more successful when the tasks require pulling motions. This makes sense, since parrots have a hooked beak that they use to pull things apart, like rotting logs to get at grubs, while corvids have straight beaks that they use to stab through things to find food.

The kea is also really sociable. Young keas play together, often using items as toys. For instance, from the same article, witnesses at a ski resort watched a kea steal a plastic mug, fly off with it, and start up a game of catch with it with a group of other keas.

The kea even has a particular call it makes to encourage other keas to play. In a recent study, when the call was broadcast to some captive keas over a loudspeaker, the keas immediately started a game of chase. Researchers think the call isn’t so much an invitation to play but is more like laughter which makes other keas want to laugh along, or in this case play.

This is what the play call sounds like:

[kea call]

The kea builds its nests in burrows it digs in the ground, with some burrows 20 feet long, or 6 meters. The nesting chamber is lined with soft plant material. Females lay two to five eggs, which hatch in about three weeks. Despite the parents’ care, more than half of babies don’t survive their first year, mostly due to introduced predators like rats, stoats, and possums. But if a kea survives to grow up, it can live up to 50 years or possibly more.

Young keas, like young adult humans, can cause a lot of mischief that sometimes leads to tragedy. A lot of keas are killed by cars because they find cars and roads interesting. They especially like to move road cones, which of course is also dangerous to humans. One community set up a kea jungle gym well off the road to give keas a safe place to play, and it succeeded so well that other communities have built kea jungle gyms too.

Kea numbers are improving slowly, with an estimated 7,000 individuals alive today. Part of the problem is that keas find humans interesting. They like our things, which they want to steal or destroy, and they like our junk food, which they want to eat. In other words, they’re suspiciously like us. Only they can fly.

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

Thanks for listening!


Episode 293: Bat-Winged Dinosaurs and an Actual Bat



We’ll have a real episode next week but for now, here are two Patreon episodes smashed together into one!

Happy birthday to Speed!

Further reading:

Yi qi Is Neat But Might Not Have Been the Black Screaming Dino-Dragon of Death

Yi qi could probably glide instead of actually flying:

The Dayak fruit bat [photo by Chien C. Lee]:

Show transcript:

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

I’ve finally finished moving, although I’m still in the process of unpacking and finding places for all my stuff. I haven’t had the chance to do any research this week, so this episode is actually two repurposed Patreon episodes, one from June of 2019 and one from May of 2021. They’re both short episodes so I put them together. I apologize to patrons for not getting something new this week, but I think everyone else will find these animals interesting.

But first, we have a birthday shout-out! A great big happy birthday to Speed! I hope this next year is the very best one yet for you!

Please excuse the varying quality of audio.

Listener Simon sent me an article about a recently discovered dinosaur with batlike wings, only the second batwinged dinosaur ever discovered. I thought that would make a really neat episode, so thank you, Simon!

These are really recent discoveries, both from the same area of northeastern China. In 2007 a small fossil found by a farmer was bought by a museum. A paleontologist named Xing Xu thought it looked interesting. Once the fossil had been cleaned and prepared for study, Xing saw just how interesting it was.

The dinosaur was eventually named Yi qi, which means strange wing. It was found in rocks dated to about 163 million years ago. Yi qi was about the size of a pigeon and was covered with feathers. The feathers were probably fluffy rather than the sleek feathers of modern birds. But most unusual was a long bony rod that grew from each wrist, called a styliform element. Yi qi also had very long third fingers on each hand. The long finger was connected to the wrist rod by a patagium, or skin membrane, and another patagium connected the wrist rod to the body. So even though it had feathers on its body, it probably didn’t have feathered wings. Instead, its forelimbs would have somewhat resembled a bat’s wings.

Paleontologists have studied the fossilized feathers with an electron microscope and discovered the structures of pigments that would have given the feathers color. Yi qi was probably mostly black with yellow or brown feathers on the head and arms. It probably also had long tail feathers to help stabilize it in the air.

Ambopteryx longibrachium was only discovered in 2017, also in northeastern China. It also lived around 163 million years ago and looked a lot like Yi qi. The fossil is so detailed it shows an impression of fuzzy feathers and even the contents of the animal’s digestive tract. Its body contained tiny gizzard stones to help it digest plants but also some bone fragments from its last meal, so paleontologists think it was an omnivore. Its hands have styliform elements, although not a wrist rod like Yi qi, and there’s a brownish film preserved across one of its arms that researchers think are remains of a wing membrane.

Paleontologists think the bat-winged dinosaurs were technically gliders. Careful examination of the wrist rods show no evidence that muscles were attached, so the dinosaurs wouldn’t have been able to adjust the wings well enough to actually fly. Modern bats have lots of tiny muscles in their wing membranes to help them fly.

Yi qi’s wrist rod isn’t unique in the animal world. The flying squirrel has styliform rods made of cartilage that project from the wrists, with the patagia attached to them. When a squirrel wants to glide, it extends its arms and legs and also extends the wrist rods, stretching the patagia taut. It can even control its glide to some extent by adjusting the wrist rods.

These two bat-winged dinosaurs were related, but they aren’t direct ancestors to modern-day birds. They’re scansoriopterygids,[scan-soarie-OPterigid] which are related to the group of dinosaurs that gave rise to birds. We only have five scansoriopterygid fossils, all found in the same area of China, but they’re all exceptionally well preserved fossils. Scansoriopterygids all appear to have been good climbers. They probably mostly lived in trees and mostly ate insects and small animals, gliding from branch to branch like modern flying squirrels do.

Researchers suggest the bat-winged dinosaurs might have gone extinct when bird ancestors evolved true flight with feathered wings, outcompeting the bat-winged dinosaurs’ more limited gliding flight. But with so few fossils, it’s impossible to say how successful the bat-winged dinosaurs were. All we know is they are rare in the fossil record and left no descendants.

So were scansoriopterygids related to pterosaurs? Nope. Pterosaurs weren’t even dinosaurs. They were reptiles and the first vertebrates we’ve found that could actually fly instead of just glide. Pterosaurs first appear in the fossil record around 228 million years ago and they all went extinct about 66 million years ago in the Cretaceous-Paleogene extinction event.

When Yi qi’s description was first published in 2015, the media acted as though it was a radical new find that would change the way we looked at dinosaurs forever. Some people even claimed the fossil was a fake, either a deliberate fraud by Xing and the other paleontologists that worked on the specimen, or that Xing and the others actually had a fossil made up of more than one animal with the bones jumbled together, which they had mistaken for a single animal. But this isn’t the case. Yi qi has been studied extensively with all the technology paleontologists have available these days. It’s the fossil of a single animal and it hadn’t been touched up or altered or messed with in any way before it was prepared by an expert. But while it is a radical new finding, it’s not as radical as some articles made it seem.

In 2008, the description was published of another scansoriopterygid called Epidexipteryx. Epidexipteryx appears to be closely related to Yi qi. It doesn’t have a wrist rod, but its arms were long and its fingers were especially elongated. It had forward-pointing teeth in the front of its jaw and probably had long tail feathers. Paleontologists think it was most likely a strong climber that may have spent most of its time in and around trees. But after that publication, paleontologist Andrea Cau published a paper suggesting that Epidexipteryx’s elongated arms and fingers might have been connected with patagia that allowed it to glide short distances. This was before the first paper about Yi qi was published and before Ambopteryx was even discovered. So the idea of a dinosaur with gliding membranes was already out there.

Hopefully, more scansoriopterygid fossils will be found and studied soon, which will give us more knowledge about what these little animals really looked and acted like. I want one as a pet.

Next, let’s go from bat-winged dinosaurs to some actual bats, specifically an unusual feature found in at least one species of bat, and something of a mystery.

As you probably know, only female mammals lactate. That just means that after a mammal gives birth, the mother produces milk for her baby to drink until it’s old enough to eat the same food that its parents do. All mammals do this, from whales to vampire bats, from humans to kangaroos, from mice to lions. The word mammal actually comes from mammary gland, which is the gland that allows a mother animal to produce milk after she has a baby.

Researchers have examined the genes that allow for milk production and determined that the genes probably developed over 200 million years ago in the common ancestor of all mammals alive today. The genes responsible for making egg yolk proteins started to be lost around 70 million years ago, except in monotremes that still lay eggs. Monotremes are platypuses and echidnas, and while they’re mammals, they retain some features that modern mammals have lost, like egg-laying. But even monotreme mothers produce milk.

Once our far-distant mammal ancestors evolved the ability to feed its babies with milk, the babies didn’t need as much yolk in their eggs. Gradually, over millions of generations, mammals lost the ability to produce egg yolks completely. I mean, except for the monotremes. From now on just assume that any time I talk about modern mammals, in this episode at least, I’m excluding monotremes, because they’re weird.

Ancient mammals laid eggs like reptiles and birds do, with a shell protecting the yolk and other fluids inside, that in turn protected and nourished the growing baby. But eventually a mammal mother retained her eggs in the body, which meant they didn’t need an eggshell since they were safely inside her, and because she was able to feed them nutritious, easy to digest milk as soon as they were born, they didn’t need an egg yolk either. So mammals eventually lost the ability to produce eggs at all.

This gets confusing, of course, because we use the same word, “egg,” to refer to the egg that a chicken or turtle lays, and to refer to the cell that a mother animal produces that can develop into a baby if it’s fertilized by sperm. Obviously I’m just talking about the first kind of egg here.

Anyway, milk production is a complex process that can be hard on the mother’s body, since she has to produce enough nutrients to feed all her babies, whether that’s just one human infant or twin fawns or a whole litter of puppies or kittens. Researchers have compared the genes associated with milk production and discovered that it’s pretty standard across all mammals. While the nutrients available in milk vary from species to species, since not every mammal has the same nutritional needs, how the body produces milk is pretty much identical across the board. All female mammals produce milk after they give birth, but only the females.

If that’s the case, though, why do male mammals have nipples? It turns out that nipples are just part of the basic body plan of a mammal. Some researchers think that originally both males and females lactated, but over the generations males lost the ability.

Except in one case. In that species, the females produce milk…and so do the males.

The Dayak fruit bat lives in parts of southeast Asia and is quite rare. It lives in rainforests and mostly eats fruit, especially figs. It has short, gray-brown fur and only weighs a little more than three ounces, or 95 grams. That’s about the same weight as a deck of cards. Its wingspan is about 18 inches across, or 46 cm. It’s a nocturnal bat but it’s also a megabat, which if you remember episode 88 means that it doesn’t have the advanced echolocation ability that microbats have. It may only navigate through the trees using its vision, since it has large eyes, but it may have some form of echolocation ability we don’t know about yet. There’s a whole lot we don’t know about the Dayak fruit bat.

What we do know is that in summer, female Dayak fruit bats give birth to one or two babies. We also know that in summer, when researchers net bats to examine, both males and females have enlarged breasts that produce milk. The bat, by the way, has breasts toward the sides of its body, basically in the armpits of its wings because that’s most convenient for the baby bats to grab hold of.

That’s all we know so far. We don’t know for sure that the males actually nurse their babies. They don’t produce nearly as much milk as females do, only about 1/10th as much. Some researchers think the father bat may take care of his babies while the mother finds food, but that she takes care of them the rest of the time. That’s just speculation, though, because so little is known about the bat.

Sometimes various diseases, genetic issues, or pollutants in the environment will cause a male animal to produce a little milk, but that’s rare. All the male Dayak fruit bats caught in summer were lactating, as were the females. Males and females caught at other times of the year weren’t lactating. Since mammals stop producing milk after their babies no longer need it, that means both males and females are probably producing milk for babies.

There may be one other bat where males lactate, although I can’t find enough information to verify it. The Bismarck masked flying fox, which sounds like an old-timey superhero, is related to the Dayak fruit bat, since they’re both megabats, but they’re not closely related.

The Bismarck masked flying fox lives in Papua New Guinea and eats fruit and other plant material. Like other flying foxes, it probably finds its food by smell and can’t echolocate. We don’t know much about it either, though, and until 2001 researchers thought it was a subspecies of Temminck’s flying fox. If you do a search for it online, every entry you find will mention that the males lactate, but never with any documentation to back up the claim. So that’s a mystery for now, although I’ll keep trying to find out more.

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

Thanks for listening!


Episode 292: The Kunga



This week let’s learn about a mystery that was solved by science!

Happy birthday to Zoe!

Further reading:

Let’s all do the kunga!

The kunga, as depicted in a 4500-year-old mosaic:

The Syrian wild ass as depicted in a 1915 photograph (note the size of the animal compared to the man standing behind it):

Domestic donkeys:

Show transcript:

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

As this episode goes live, I should be on my way home from Dragon Con, ready to finish moving into my new apartment! It’s been an extremely busy week, so we’re just going to have a short episode about a historical mystery that was recently solved by science.

But first, we have another birthday shout-out! Happy birthday to Zoe, and I hope you have the most sparkly and exciting birthday ever, unless you’d rather have a chill and low-key birthday, which is just as good depending on your mood.

This week we’re going to learn about an animal called the kunga, which I learned about on Dr. Karl Shuker’s blog. There’s a link in the show notes if you’d like to read his original post.

The mystery of the kunga goes back thousands of years, to the fertile crescent in the Middle East. We’ve talked about this area before in episode 177, about the sirrush, specifically Mesopotamia. I’ll quote from that episode to give you some background:

“These days the countries of Iraq and Kuwait, parts of Turkey and Syria, and a little sliver of Iran are all within what was once called Mesopotamia. It’s part of what’s sometimes referred to as the Fertile Crescent in the Middle East. The known history of this region goes back five thousand years in written history, but people have lived there much, much longer. Some 50,000 years ago humans migrated from Africa into the area, found it a really nice place to live, and settled there.

“Parts of it are marshy but it’s overall a semi-arid climate, with desert to the north. People developed agriculture in the Fertile Crescent, including irrigation, but many cultures specialized in fishing or nomadic grazing of animals they domesticated, including sheep, goats, and camels. As the centuries passed, the cultures of the area became more and more sophisticated, with big cities, elaborate trade routes, and stupendous artwork.”

The domestic horse wasn’t introduced to this area until about 4,000 years ago, although donkeys were common. The domestic donkey is still around today, of course, and is descended from the African wild ass. Researchers estimate it was domesticated 5- or 6,000 years ago by the ancient nomadic peoples of Nubia, and quickly spread throughout the Middle East and into southern Asia and Europe.

But although horses weren’t known in the Middle East 4,500 years ago, we have artwork that shows an animal that looks like a really big donkey, much larger than the donkeys known at the time. It was called the kunga and was highly prized as a beast of burden since it was larger and stronger than an ordinary donkey. It was also rare, bred only in Syria and exported at high prices. No one outside of Syria knew what kind of animal the kunga really was, but we have writings that suggest it was a hybrid animal of some kind. This explains why its breeding was such a secret and why it couldn’t be bred elsewhere. Many hybrid animals are infertile and can’t have babies.

If the artwork was from later times, we could assume it showed mules, the offspring of a horse and a donkey. But horses definitely weren’t known in the Middle East or nearby areas at this time, so it can’t have been a mule.

The kunga was used as a beast of burden to pull plows and wagons, but the largest individuals were used to pull the chariots of kings. Fortunately, the kunga was so highly prized that it was sometimes sacrificed and buried with important people as part of their grave goods. Archaeologists have found a number of kunga skeletons, together with ceremonial harnesses. Unfortunately, it’s actually difficult to tell the difference between the skeletons of various equids, including horses, donkeys, zebras, and various hybrid offspring like mules. All scientists could determine is that the kunga most closely resembled various species and subspecies of donkey.

In January 2022, the mystery was finally solved. A genetic study of kunga remains was published that determined that the kunga was the offspring of a female domesticated donkey and a male Syrian wild ass.

The Syrian wild ass was native to many parts of western Asia. It was barely more than three feet tall at the shoulder, or about a meter, and while it was admired as a strong, beautiful animal that was sometimes hunted for its meat and skin, it couldn’t be tamed.

Because the Syrian wild ass was a different species of equid from the domesticated donkey, and because it couldn’t be tamed and was hard to catch, breeding kungas would be difficult. Male wild asses had to be captured, probably when young, and kept with female donkeys in hopes that they would mate eventually and offspring would result. Obviously the kunga showed what’s called hybrid vigor, where a hybrid is stronger than either of its parents, but because it was also infertile, the largest and strongest kungas couldn’t be bred together. Each kunga had to be bred from a pairing of wild ass and domestic donkey. No wonder it was expensive!

When the horse was introduced to the Middle East, it took the place of the kunga quickly and before long everyone had forgotten what the kunga even was.

Sadly, we can’t try to breed a kunga today to see what it was really like, because the Syrian wild ass went extinct in 1927. But the endangered Persian wild ass was introduced to parts of the Middle East starting in 2003, including Saudi Arabia, Iran, and Israel, to take the place of its extinct Syrian relation, and its numbers are increasing.

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

Thanks for listening!


Episode 291: The Ediacaran Biota



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

A very happy birthday to Isaac!

Further reading:

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

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

Charnia looks like a leaf or feather:

Kimberella looks like a lost earring:

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

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

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

Trilobozoans look like the Manx flag or a cloverleaf roll:

Cochleatina looked like a snail:

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!


Episode 290: Lobsters!



Thanks to Pranav for this week’s suggestion, lobsters!

Happy birthday to Jake!!

Visit Dr. Oné R. Pagán’s site for links to his podcast and his free book Arrow: The Lucky Planarian! You can also order his other books from your favorite book store. Here’s the direct link to his interview with me!

Further reading:

Don’t Listen to the Buzz: Lobsters Aren’t Actually Immortal

An ordinary lobster:

A blue lobster!

The scampi looks more like a prawn/shrimp than a lobster, but it’s a lobster:

 

The rosy lobsterette is naturally red because it lives in the deep sea:

The deep-sea lobster Dinochelus ausubeli was only discovered in 2007 and described in 2010:

Show transcript:

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

As invertebrate August continues, this week we’re going to talk about lobsters. Thanks to Pranav for the suggestion!

But first, we have a birthday shout-out! A great big happy birthday this week to Jake! I hope your birthday is epic fun!

I’d also like to let you know that Dr. Oné R Pagán interviewed me recently about my book, Beyond Bigfoot & Nessie: Lesser-Known Mystery Animals from Around the World, and you can hear that interview on his podcast, the Baldscientist Podcast. Baldscientist is all one word. I’ll put a link in the show notes. While you’re at it, you should definitely buy his books, including his latest one, Drunk Flies and Stoned Dolphins: A Trip Through the World of Animal Intoxication, which just came out this year and is a lot of fun, as well as being full of interesting science! He also has a free children’s story called Arrow, the Lucky Planarian that you can download and read. It’s completely charming and you’ll learn a lot about planarians, which are also called flatworms, which are invertebrates, so this is all coming together!

This week’s episode isn’t about planarians, though, but about lobsters. I don’t think we’ve ever discussed lobsters on the podcast before, oddly enough, but it’s been on my ideas list for a long time. When Pranav emailed me recently to suggest we do a lobster episode, I realized it was time! Time for lobsters!

The lobster is a crustacean, and while there are plenty of different lobsters in the world, we’re going to focus on the clawed lobsters this time. There are lots of them, all grouped in the family Nephropidae.

The lobster has eight legs that it walks on, and two more legs with pincers. That’s why it’s in the order Decapoda. Deca means ten and poda means feet. Ten feet. Some of which can pinch you if you’re not careful.

The lobster uses its claws to defend itself from potential predators, and uses them to grab and kill small animals. It eats pretty much anything it can find, from fish and squid to sea stars and mollusks, to dead animals and some plant material. But its claws are too big and clumsy to use to eat with, which is why it has much smaller pincers on its next pairs of legs. These pincers are equipped with chemoreceptors that allow the lobster to taste its food before it actually eats it, which is a neat trick.

The lobster uses these small claws to pull its food into smaller pieces and convey it to the mouthparts, which are under its head. Some mouthparts have sensory hairs that can taste food, some have sharp spines that act as teeth to tear food into smaller pieces, and others are small and just flutter to help keep pieces of food from floating away. The stomach is only about an inch away from the mouth, or about 2.5 cm, no matter the size of the lobster. The stomach itself, and the short esophagus leading to the stomach, are lined with chitin spines that act like teeth to grind food up while enzymes break it down to fully digest it. This seems like a really complicated way to eat, but it’s actually not all that different from the way we eat, it’s just that instead of mouthparts and stomach teeth, we do all our grinding up of food in the mouth with just one set of teeth.

The lobster’s body is protected by an exoskeleton made of chitin, but the trouble with exoskeletons is that they don’t grow. The lobster has to shed its exoskeleton every so often and grow a new one that fits better, and until the new exoskeleton has hardened, the lobster is vulnerable and will usually hide. This can take several weeks. When a lobster is young and growing rapidly, it may molt its exoskeleton every few months or even more often, while an adult lobster typically only molts once every year or two.

Molting takes energy, though, and the bigger a lobster is, the more energy it takes to molt. It’s not like taking off a shirt. The lobster has to wriggle carefully out of its exoskeleton through a split between its tail and abdomen, making sure not to hurt its soft body in the process, and it even molts its stomach teeth, more properly called a gastric mill.

It’s a long, difficult process, during which time the lobster is mostly helpless. Some studies indicate that something like 10% of all lobsters actually die during the molting process. A lobster usually eats its shed exoskeleton in order to extract calcium from it, which helps its new exoskeleton harden faster.

Unlike many animals, lobsters keep growing throughout their lives. Since they can live a long time, that means sometimes people catch really big lobsters. The biggest ever reliably measured was an American lobster caught in 1977 off the coast of Nova Scotia, Canada in North America. It weighed 44 lbs, 6 oz, or 20.14 kg and was 3.5 feet long, or 106 cm. A more ordinary weight of a good-sized lobster is about 2 lbs, or 910 grams.

The lobster can definitely live at least 50 years, and some researchers suggest it can live much longer than that. But it’s really hard to tell the age of a lobster. You can’t go by size since individual lobsters grow at different rates depending on how much food they can find and other factors. A study published in September 2021 reports that a DNA test of genetic modifications that lobsters and other animals accumulate during their lives can determine a lobster’s age with a good degree of accuracy. This is important since it will help conservationists learn more about lobster populations, many of which are under increasing pressure from commercial fishing.

There’s a lot of talk online about how the lobster is actually immortal, and that if nothing kills it, it will just live forever. This rumor got started when scientists reported that lobsters express an enzyme called telomerase that repairs damage to DNA sequences at the ends of chromosomes. Most adult animals lose the ability to express telomerase, but the lobster doesn’t.

But lobsters aren’t immortal. A really old lobster stops shedding its exoskeleton, which slowly becomes more and more battered. The exoskeleton is part of the lobster’s body and can contract bacterial infections when it’s injured. Sometimes the infections are bad enough that it fuses the exoskeleton to the body permanently, so if the lobster does eventually get to the point where it can molt, it gets stuck trying to and dies. Sometimes the exoskeleton just rots away, which leads to the lobster’s death.

Still, the telomerase probably helps the lobster live for such a long time. Now that scientists have a way to determine a lobster’s actual age without harming it, hopefully soon we’ll learn more about how old they really get. We might be surprised, who knows?

Most species of lobster are brown, black, or greenish, which helps them hide on the sea floor. When a lobster is cooked by boiling, chemicals in its exoskeleton react with the hot water and turn it bright red. But sometimes—like, once every 10 million lobsters—a live lobster is found that is red. Researchers aren’t sure what causes this coloration.

Sometimes lobsters can be blue too. It’s still rare but not as rare as red coloration, estimated at about one every two million lobsters. While some species of lobster are naturally dark blue or even dark purple, a blue lobster is a really pretty shade of bright blue. It’s caused by a genetic mutation that results in it producing more of a protein that reacts with the pigments in its body, turning it blue. Since blue lobsters are so striking and attractive, lobster fishers usually either throw blue lobsters back or donate them to local aquariums. People sometimes assume blue lobsters are poisonous even though they’re not, so mostly no one wants to eat them anyway.

Lobsters are closely related to crabs and shrimp, and some clawed lobsters look a lot like their close relatives. This includes the scampi, which is the pinkish and silvery-white coloration of a prawn or shrimp, and only grows about 10 inches long at most, or 25 cm. It lives in parts of the northeastern Atlantic and parts of the Mediterranean Sea, where it digs a burrow in the muddy sea floor and spends most of its time hiding. It eats worms, small fish, jellyfish, and anything else it can catch. There are other species of scampi that live in other parts of the world’s oceans too.

Another lobster that looks even more like a shrimp is the rosy lobsterette, which only grows about 5 inches long, or 13 cm, and which is naturally red. This isn’t a rare coloration but an adaptation to its habitat. Unlike most lobsters, which live in shallow coastal waters, the rosy lobsterette lives in much deeper water where there’s very little light. As we’ve talked about before, the wavelength of light that is red can’t penetrate very far into water, so a red animal in the deep sea is basically invisible. A lot of deep-sea animals can’t even perceive the color red. The rosy lobsterette lives in the Gulf of Mexico, around the Caribbean, and in the western Atlantic Ocean.

There are actually quite a few species of lobster that live in the deep sea, with more being discovered every so often. In 2010 a new species of deep-sea lobster was described, Dinochelus ausubeli, which lives near the Philippines in South Asia. It was discovered during the ten-year Census of Marine Life, which sponsored 540 expeditions by thousands of scientists all over the world. It only grows a few inches long, or about 5 cm, and is mostly transparent with some pinkish coloring. It has one really long, thin, spiny claw with a bulbous base, while the other claw is much smaller.

There are a whole lot of other clawed lobster species, some of them known from only a few specimens. The Cape lobster, for instance, lives off the coast of South Africa in rocky areas, and even though it’s been known to science since the late 18th century, we don’t know much about it. It’s small, only growing about 4 inches long, or 10 cm, and ranges in coloration from greenish to yellowish to brown, even sometimes red, and it looks like a miniature version of the European or American lobsters although it’s not very closely related. In 1992 someone found one, which was such a rare occurrence that it was reported in the news. It was only the 14th specimen ever found at the time, although the publicity it received got other people out looking for the little lobster and more have been found since.

In other words, there are undoubtedly lots more species of lobster than we know about, just waiting to be discovered.

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

Thanks for listening!


Episode 289: Weird Worms



This week we learn about some weird worms!

Further reading:

Otherworldly Worms with Three Sexes Discovered in Mono Lake

Bizarre sea worm with regenerative butts named after Godzilla’s monstrous nemesis

Underground giant glows in the dark but is rarely seen

Giant Gippsland earthworm (you can listen to one gurgling through its burrow here too)

Further watching:

A giant Gippsland earthworm

Glowing earthworms (photo by Milton Cormier):

This sea worm’s head is on the left, its many “butts” on the right [photo from article linked to above]:

A North Auckland worm [photo from article linked to above]:

A giant beach worm:

Show transcript:

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

This week we continue Invertebrate August with a topic I almost saved for monster month in October. Let’s learn about some weird worms!

We’ll start with a newly discovered worm that’s very tiny, and we’ll work our way up to larger worms.

Mono Lake in California is a salty inland lake that probably started forming after a massive volcanic eruption about 760,000 years ago. The eruption left behind a crater called a caldera that slowly filled with water from rain and several creeks. But there’s no outlet from the lake—no river or even stream that carries water from the lake down to the ocean. As a result, the water stays where it is and over the centuries a lot of salts and other minerals have dissolved into the lake from the surrounding rocks. The water is three times as salty as the ocean and very alkaline.

No fish live in the lake, but some extremophiles do. There’s a type of algae that often turns the water bright green, brine shrimp that eat the algae, some unusual flies that dive into the water encased in bubbles, birds that visit the lake and eat the brine shrimp and flies, and eight species of worms that have only been discovered recently. All the worms are weird, but one of them is really weird. It hasn’t been described yet so at the moment is just going by the name Auanema, since the research team thinks it probably belongs in that genus.

Auanema is microscopic and lives throughout the lake, which is unusual because the lake contains high levels of arsenic. You know, a DEADLY POISON. But the arsenic and the salt and the other factors that make the lake inhospitable to most life don’t bother the worms.

Auanema produces offspring that can have one of three sexes: hermaphrodites that can self-fertilize, and males and females that need each other to fertilize eggs. Researchers think that the males and females of the species help maintain genetic diversity while the hermaphrodites are able to colonize new environments, since they don’t need a mate to reproduce.

When some of the worms were brought to the laboratory for further study, they did just fine in normal lab conditions, without extreme levels of arsenic and so forth. That’s unusual, because generally extremophiles are so well adapted for their extreme environments that they can’t live anywhere else. But Auanema is just fine in a non-harsh environment. Not only that, but the team tested other species in the Auanema genus that aren’t extremophiles and discovered that even though they don’t live in water high in arsenic, they tolerate arsenic just as well as the newly discovered species.

The team’s plan is to sequence Auanema’s genome to see if they can determine the genetic factors that confer such high resistance to arsenic.

Next, we go up in size from a teensy worm to another newly discovered worm, this one only about 4 inches long at most, or 10 cm. It’s a marine polychaete worm that lives inside sea sponges, although we don’t know yet if it’s parasitizing the sponge or if it confers some benefit to the sponge that makes this a symbiotic relationship. The worm was only discovered in 2019 near Japan and described in early 2022 as Ramisyllis kingghidorahi.

Almost all worms known are shaped, well, like worms. They have a mouth at one end, an anus at the other, and in between they’re basically just a tube. Ramisyllis is one of only three worms known that have branched bodies, which is why they’re called branching sea worms. In this case, Ramisyllis has a single head, which stays in the sponge, but its other end branches into multiple tail ends that occasionally break off and swim away. The tails are specialized structures called stolons. When a stolon breaks off, it swims away and releases the eggs or sperm it contains into the water before dying. The worm then regenerates another stolon in its place.

Ramisyllis’s branches are asymmetrical and the worms found so far can have dozens of branches. Its close relation, a species that lives in sponges off the coast of northern Australia, can have up to 100 branches. Researchers suspect that there are a lot more species of branching sea worms that haven’t been discovered yet.

Next, let’s head back to land to learn about a regular-sized earthworm. There are quite a few species across three different earthworm families that exhibit a particular trait, found in North and South America, Australia and New Zealand, and parts of Africa. A few species have been introduced to parts of Europe too. What’s the trait that links all these earthworms? THEY CAN GLOW IN THE DARK.

Bioluminescent earthworms don’t glow all the time. Most of the time they’re just regular earthworms of various sizes, depending on the species. But if they feel threatened, they exude a special slime that glows blue or green in the dark, or sometimes yellowish like firefly light. The glow is caused by proteins and enzymes in the slime that react chemically with oxygen.

Researchers think that the light may startle predators or even scare them away, since predators that live and hunt underground tend to avoid light. The glow may also signal to predators that the worm could taste bad or contain toxins. The light usually looks dim to human eyes but to an animal with eyes adapted for very low light, it would appear incredibly bright.

One bioluminescent earthworm is called the New Zealand earthworm. It can grow up to a foot long, or 30 cm, although it’s only about 10 mm thick at most, and while it’s mostly pink, it has a purplish streak along the top of its body (like a racing stripe).

Like other earthworms, the New Zealand earthworm spends most of its time burrowing through the soil to find decaying organic matter, mostly plant material, and it burrows quite deep, over 16 feet deep, or 5 meters. If a person tried to dig a hole that deep, without special materials to keep the hole from collapsing, it would fall in and squish the person. Dirt and sand are really heavy. The earthworm has the same problem, which it solves by exuding mucus from its body that sticks to the dirt and hardens, forming a lining that keeps the burrow from collapsing. This is a different kind of mucus than the bioluminescent kind, and all earthworms do this. Not only does the burrow lining keep the worm safe from being squished by cave-ins, it also contains a toxin that kills bacteria in the soil that could harm the worm.

Worms that burrow as deep as the New Zealand earthworm does are called subsoil worms, as opposed to topsoil worms that live closer to the surface. Topsoil contains a lot more organic material than subsoil, but it’s also easier for surface predators to reach. That’s why topsoil worms tend to move pretty fast compared to subsoil worms.

The New Zealand earthworm glows bright orange-yellow if it feels threatened, so bright that the Maori people used the worm as bait when fishing since it’s basically the best fish lure ever.

Another New Zealand earthworm is called the North Auckland worm, and while it looks like a regular earthworm that’s mostly pink or greenish, it’s also extremely large. Like, at least four and a half feet long, or 1.4 meters, and potentially much longer. It typically lives deep underground in undisturbed forests, so there aren’t usually very many people around on the rare occasion when heavy rain forces it to the surface. Since earthworms of all kinds absorb oxygen through the skin, instead of having lungs or gills, they can’t survive for long in water and have to surface if their burrow completely floods.

We don’t actually know that much about the North Auckland worm. Like the New Zealand earthworm, it’s a subsoil worm that mostly eats dead plant roots. Some people report that it glows bright yellow, although this hasn’t been studied and it’s not clear if this is a defensive reaction like in the New Zealand earthworm. It’s possible that people get large individual New Zealand earthworms confused with smaller North Auckland worm individuals. Then again, there’s no reason why both worms can’t bioluminesce.

An even bigger worm is the giant beach worm. It’s a polychaete worm, not an earthworm, and like other polychaete worms, including the branching sea worm we talked about earlier, it has a segmented body with setae that look a little like legs, although they’re just bristles. The giant beach worm’s setae help it move around through and over the sand. It hides in a burrow it digs in the sand between the high and low tide marks, but it comes out to eat dead fish and other animals, seaweed, and anything else it can find. It has strong jaws and usually will poke its head out of its burrow just far enough to grab a piece of food. It has a really good sense of smell but can’t see at all.

There are two species of giant beach worm that live in parts of Australia, especially the eastern and southeastern coasts, where people dig them up to use as fish bait. The largest species can grow up to 8 feet long, or 2.4 meters, and possibly even longer. There are also two species that live in Central and South America, although we don’t know much about them.

Another huge Australian worm is the endangered Giant Gippsland earthworm that lives in Victoria, Australia. It’s also a subsoil worm and is about 8 inches long, or 20 cm…when it’s first hatched. It can grow almost ten feet long, or 3 meters. It’s mostly bluish-gray but you can tell which end is its head because it’s darker in color, almost purple. It lives beneath grasslands, usually near streams, and is so big that if you happen to be in the right place at the right time on a quiet day and listen closely, you might actually hear one of the giant worms moving around underground. When it moves quickly, its body makes a gurgling sound as it passes through the moist soil in its burrow.

The Giant Gippsland earthworm is increasingly endangered due to habitat loss. It also reproduces slowly and takes as much as five years to reach maturity. Conservationists are working to protect it and its remaining habitat in Gippsland. The city of Korumburra used to have a giant worm festival, but it doesn’t look like that’s been held for a while, which is too bad because there aren’t enough giant worm festivals in the world.

To finish us off, let’s learn what the longest worm ever reliably measured is. It was found on a road in South Africa in 1967 and identified as Microchaetus rappi, or the African giant earthworm. It’s mostly dark greenish-brown in color and it looks like an earthworm, because it is an earthworm. On average, this species typically grows around 6 feet long, or 1.8 meters, which is pretty darn big, but this particular individual was 21 feet long, or 6.7 meters. It’s listed in the Guinness Book of World Records as the longest worm ever measured. Beat that, other worms. I don’t think you can.

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

Thanks for listening!


Episode 288: Mystery Invertebrates



Thanks to Joel for suggesting this week’s topic!

Happy birthday to Fern this week!

Further reading:

Small, rare crayfish thought extinct is rediscovered in cave in Huntsville city limits

Hundreds of three-eyed ‘dinosaur shrimp’ emerge after Arizona monsoon

An invertebrate mystery track in South Africa

The case of the mysterious holes in the sea floor

Contemplating the Con Rit

The Shelton Cave crayfish, rediscovered:

The three-eyed “tadpole shrimp” or “dinosaur shrimp,” triops [photo from article linked above]:

A leech track in South Africa [photo from article linked above]:

A track, or at least a series of holes, discovered in the deep seafloor [photos from article linked above]:

Show transcript:

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

Thanks to Joel who suggested we do an episode about mystery invertebrates! It took me a while, but I think you’re really going to like this episode. Some of the mysteries are solved and some are not, but they’re all fun.

Before we get to the mystery animals, though, we have a birthday shout-out! A great big happy birthday to Fern! I hope you have your favorite type of birthday cake or other treat and get to enjoy it with your loved ones.

Our first mystery starts in a cave near Huntsville, Alabama in the southern United States, which is in North America. Shelta Cave is a relatively small cave system, only about 2,500 feet long, or 760 meters. That’s about half a mile. It’s a nature preserve now but in the early 1900s it was used as an underground dance hall with a bar and everything.

Biologist John Cooper studied the cave’s aquatic ecosystem in the 1960s when he was doing his dissertation work. His wife Martha helped him since they were both active cavers. At the time, the cave ecosystem was incredibly diverse, including three species of crayfish. One was called the Shelta Cave crayfish, which was only a few inches long, or about 5 cm, mostly translucent or white since it didn’t have any pigment in its body, and with long, thin pincers.

It was rarer than the cave’s other two crayfish species, and unlike them it had only ever been found in Shelta Cave. From 1963 to 1975, only 115 individuals had been confirmed in repeated studies of the cave’s ecosystem.

Then, in the 1970s, several things happened that caused a serious decline in the diversity of life in the cave.

The first was development of the land around the cave into subdivisions, which meant that more pesticides were used on lawns and flower beds, which made its way into the groundwater that entered the cave. It also meant more people discovering the cave and going in to explore, which was disturbing a population of gray bats who also lived in the cave. To help the bats and keep people out, the park service put a gate over the entrance, but the initial gate’s design wasn’t a very good one. It kept people out but it also made it harder for the bats to go in and out, and eventually the bats gave up and moved out of the cave completely. This really impacted the cave’s ecosystem, since bats bring a lot of nutrients into a cave with their droppings and the occasional bat who dies and falls to the cave floor.

The gate has since been replaced with a much more bat-friendly one, but studies afterwards showed that a lot of the animals found in the cave had become rare. The Shelta Cave crayfish had disappeared completely. One was spotted in 1988 but after that, nothing, and the biologists studying the cave worried that it had gone extinct.

Then, in 2019, a team of scientists and students surveying life in the cave spotted a little white crayfish with long, thin pincers in the water. The team leader dived down and scooped it up with his net to examine more closely. The crayfish turned out to be a female Shelta Cave crayfish with eggs, which made everyone excited, and after taking a tiny tissue sample for DNA testing, and lots of photographs, they released her back into the water. The following year they found a second Shelta Cave crayfish.

The Shelta Cave crayfish is so little known that we don’t even know what it eats or how it survives in the same environment with two larger crayfish species. Biologist Dr. Matthew Niemiller is continuing Dr. Cooper’s initial studies of the cave and will hopefully be able to learn more about the crayfish and its environment.

Next let’s travel from a cool, damp, flooded cave in Alabama to northern Arizona. Arizona is in the western United States and this particular part of the state has desert-like conditions most of the year. Almost a thousand years ago, people built what is now called Wupatki Pueblo, a 100-room building with a ballcourt out front and a big community room. It was basically a really nice apartment building. Wupatki means “tall house” in the Hopi language, and while the pueblo people who built it are long gone, Wupatki is still an important place for the Hopi and other Native American tribes in the area. It’s also a national monument that has been studied and restored by archaeologists and is open to the public.

In late July 2021, torrential rain fell over the area, so much rain that it pooled into a shallow temporary lake around Wupatki, including flooding the ballcourt. The ballcourt is 105 feet across, or 32 meters, and surrounded by a low wall. One day while the ballcourt was still flooded, a tourist came up to the lead ranger, Lauren Carter. The visitor said there were tadpoles in the ballcourt.

There are toads in the area that live in burrows and only come out during the wet season when there’s rain, and Carter thought the tadpoles might be from the toads. She went to investigate, saw what looked like tadpoles swimming around, and scooped one up in her hands to take a closer look. But the tadpoles were definitely not larval toads. In fact, they kind of looked like teensy horseshoe crabs, with a rounded shield over the front of the body and a segmented abdomen and tail sticking out from behind, with two long, thin spines at the very end that are called caudal extensions. It had two pairs of antennae and lots of small legs underneath, some adapted for swimming. The largest of the creatures were about two inches long, or 5 cm.

What on earth were they, and where did they come from? This area is basically a desert. Carter stared at the weird little things and remembered hearing about something similar when she worked at the Petrified Forest National Park, also in Arizona. She looked the animal up and discovered what it was.

It’s called Triops and is in the order Notostraca. Notostracans are small crustaceans shaped sort of like tadpoles, which is why it’s sometimes called the tadpole shrimp, but it’s not a shrimp. It has two eyes on the top of its head visible through its flattened, smooth carapace. Species in the genus Triops also have a so-called third eye between the two ordinary eyes, although it’s a very simple eye that probably only detects light and dark. Many crustaceans have these third eyes in their larval forms but very few retain them into adulthood.

Notostracans have been around for about 365 million years, and haven’t changed much in the last 250 million years. It’s an omnivore that mostly lives on the bottom of freshwater pools and shallow lakes, often temporary ones like the flooded ballcourt, although some species live in brackish water and saline pools, or permanent waterways like peat bogs.

Triops eggs are able to tolerate high temperatures and dry conditions, with the eggs remaining viable for years or even decades in the sediment of dried-up ponds. When enough water collects, the eggs hatch and within 24 hours are miniature versions of the adult Triops. They grow up quickly, lay lots of eggs, and die within a few months or when the water dries up again.

Triops eggs are even sold as aquarium pets, since they’re so unusual looking and are easy to care for. They basically eat anything. They especially like mosquito larvae, so if you see some in your local pond or other waterway, give them a tiny high-five.

In 1996, some workers near Indianapolis, Indiana were servicing a tank full of chemical byproducts from making plastic auto parts when they noticed movement in the toxic goo. They investigated and saw several squid-like creatures swimming around. They were red-brown and about 8 inches long, or 20 cm, including their arms or tentacles, but were only about an inch wide, or 2.5 cm.

The workers managed to capture one and put it in a jar, which they stuck in the break room refrigerator. By the time someone in management arranged to have it examined by a scientist, the jar had been thrown out. If you’ve ever tried to keep food in a break room fridge, you’ll know that there’s always someone who will throw out everything in the fridge that isn’t theirs, no matter whether it’s labeled or brand new or not. I have had my day’s lunch thrown out that had only been in the fridge a few hours. Anyway, when the tank was cleaned out the following year, no one found any creatures in it at all.

This sounds really interesting, but there’s precious little information to go on. The story appeared in a few newspapers but we have no names of the people who reportedly saw the creatures, no follow-up information. It has all the hallmarks of a hoax or urban legend. The creatures’ size also seems quite large for extremophiles in a small, closed environment. What would they find to eat to get so big?

Next let’s talk about some mysterious tracks made by invertebrates, as far as we know. We’ll start with a track on land that was a mystery at first, but was solved. A man in the Kruger National Park in South Africa named Rudi Hulshof came across a weird track in the sandy dirt that he didn’t recognize. It was maybe 10 mm wide and kind of looked like a series of connected rectangles, as though a tiny person was moving a tiny cardboard box by rolling it over and over, but there weren’t any footprints, just the body track.

Curious, Hulshof followed the track to find what had made it, and finally discovered the culprit. It was a leech! Most leeches live in water, whether it’s the ocean, a pond or swamp, a river, or just flooded ground. Most species are parasitic worms that attach to other animals with suckers, then pierce the animal’s skin and suck its blood. The leech stays on the animal until it’s full, then drops off. Some leeches are terrestrial, but it appears that this one was a freshwater leech that had attached to an animal passing through the water, then dropped off onto land. It had crawled as far as it could trying to find a better environment, but when Hulshof found it it was dead, so it had not had a good day.

The leech moves on land by stretching the front of its body forward, then dragging its tail end up in a bunch kind of like a worm (it is a kind of worm), so that’s why its track was so unusual-looking. It’s a good thing Hulshof found the leech before something ate it, or else he’d probably still be wondering what had made that track.

We have photographs of other tracks that are still mysterious. You may have heard about one that’s been in the news lately. This one was found by a deep-sea rover in July 2022, more than a mile and a half deep, or 2500 meters, in the north Atlantic Ocean.

The track may or may not actually be a track, although it looks like one at first glance. It consists of a line of little holes in the seafloor, one after the other, although they’re not all the same distance apart. The rover saw them on two separate dives in different locations, so it wasn’t just one track, but although the scientists operating the rover remotely tried to look into the holes, they couldn’t get a good enough view. It does look like there’s sediment piled up next to the holes, so researchers think something might actually be digging the holes, either digging down from the surface to find food hidden in the sediment, or digging up from inside the sediment to find food in the water. The rover did manage to get a sample of sediment from next to one of the holes and a water sample from just above it, and eventually those samples will be tested for possible environmental DNA that might help solve the mystery.

This wasn’t the first time these holes have been seen in the area, though. An expedition in 2004 saw them and hypothesized that the holes are made by an invertebrate with a feeding appendage of some kind that it uses to dig for food. Not only that, we have similar-looking fossil holes in rocks formed from deep marine sediments millions of years ago.

Other deep-sea tracks have a known cause, and humans are responsible. In the 1970s and 1980s, ships with deep-sea dredging equipment traveled through parts of the Pacific Ocean, testing the ocean floor to see whether the minerals in and beneath the sediment were valuable for mining. A few years ago scientists revisited the same areas to see how the ecosystems impacted by test mining had responded.

The answer is, not well. Even after 40 years or so since the deep-sea mining equipment sampled the sea floor, the marks remain. The deep sea is a fragile ecosystem to start with, and any disturbance takes a long, long time to recover—possibly thousands of years. So while the holes discovered in 2022 were almost certainly made by an animal or animals, they might be quite old.

Let’s finish with a mystery animal we’ve talked about before, but a really long time ago—way back in episode 6. It’s definitely time to revisit it.

In 1883 when he was 18 years old, a Vietnamese man named Tran Van Con had seen the body of an enormous creature washed up on shore at Hongay in Vietnam. Van Con said it was probably 60 feet long, or 18 meters, but less than three wide wide, or 90 cm. It had dark brown plates on its back with long spines sticking out from them to either side, and the segment at its tail end had two more spines pointing straight back. It didn’t have a head, which had presumably already rotted off, or something bit it off before the animal washed ashore. It had been dead for a long time considering the smell. In fact, it smelled so terrible that locals finally towed it out to sea to get rid of it. It sank and that was the last anyone ever saw of it. The locals referred to it as a con rit, which means “millipede,” since the armor plates made it look like the segmented body of an immense millipede.

Lots of people have made suggestions as to what the con rit could be, but nothing really fits. It was the length of a whale, but it doesn’t sound like any kind of whale known. The armored plates supposedly rang like metal when hit with a stick. Even if this was an exaggeration, it probably meant the armor plates were really hard, not just the skin of a dead whale that had hardened in the sun. It also implies that the plates had empty space under them, allowing them to echo when hit. Zoologist Dr. Karl Shuker suggests that the plates might have been the exoskeleton of a crustacean of some kind, which makes a lot more sense than a whale, but the sheer size of the carcass is far larger than any crustacean, or even any arthropod, ever known.

There’s also some doubt that the story is accurate. It might even be a hoax. We only know about the con rit at all because the director of Indochina’s Oceanographic and Fisheries service, Dr. A. Krempf, talked to Tran Van Con about it in 1921. That was 38 years after Van Con said he saw the creature, so he might have misremembered details. Not only that, Krempf translated the story from Vietnamese, and there’s no way of knowing how accurate his translation was.

The con rit is also a monster from Vietnamese folktales, a sort of sea serpent that had lots of feet. It was supposed to attack fishing boats to eat the sailors, until a king caught it and chopped it up into pieces. A local mountain was supposedly formed from its head, and the other pieces of its body turned into the unusual stones found on a nearby island.

There’s always the possibility that Tran Van Con actually told Krempf this folktale, but that Krempf misunderstood and thought he was telling him something he actually witnessed. Then again, there are eight reports from ships in the area between 1893 and 1915 of creatures that might have been a con rit. One account from 1899 was a sighting of a creature estimated as being 135 feet long, or 41 meters, which was rowing itself along at the surface by means of multiple fins along its sides.

Whatever the con rit was, there haven’t been any sightings since 1915. That doesn’t mean there isn’t a population of incredibly long invertebrates living in the deep ocean in southeast Asia. If it does exist, maybe one day a deep-sea rover will spot one. Maybe it dug those little holes, who knows?

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

Thanks for listening!


Episode 287: Sand Crabs, Sea Slugs, and a Mystery Octopus



Sign up for our mailing list! Even though I hardly ever send an email to it!

It’s INVERTEBRATE AUGUST! Thanks to Elizabeth, Richard, and Llewelly for their suggestions this week!

Further reading:

Meet Phylliroe: the sea slug that looks and swims like a fish

Hey, so these sea slugs decapitate themselves and grow new bodies

Found, Then Lost, Then Found Again: Scientists Have Rediscovered the Sand Octopus

A sand crab in the air:

Sand crabs in the water, feeding:

Phylliroe is a sea slug that looks like a fish (pictures from article linked to above):

How I used to draw snails when I was a kid, adding an extra foot because I didn’t understand that the “foot” of a snail/slug is the flat part of the body that touches the ground:

The mysterious sand octopus in mid-swim:

Show transcript:

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

It’s the first week of invertebrate August and we’re heading to the ocean for our first episode! Let’s jump right in with an episode about sand crabs, a couple of sea slugs, and an octopus mystery that was recently solved. Thanks to Elizabeth, my brother Richard, and Llewelly for their suggestions!

We’ll start with Elizabeth’s suggestion. The sand crab is also called the sand bug, the mole crab, or similar names that refer to its habit of burrowing into the sand. It’s common throughout much of the world’s oceans, especially in warm areas, and can be extremely numerous. It’s also sometimes called the sand flea, but it’s not the kind of tiny jumping crustacean that bites, also called the sand flea. This little crustacean is harmless to humans. It doesn’t even have pincers.

The sand crab isn’t a true crab although it is closely related to them. It’s gray-brown and has a tough carapace to protect it when it’s washed around by waves and to help protect it from predators. Females are larger than males and can grow up to an inch and a half long in the largest species, or about 35 mm, and an inch wide, or 25 mm. So it’s longer than it is wide, unlike most crabs, and its carapace is domed sort of like a tiny tortoise shell. Overall, it’s shaped sort of like a streamlined barrel. I saw one site that called it the sand cicada and it is actually about the same size and shape as a cicada, which it isn’t related to at all except that they’re both invertebrates. Some species have little spines on the carapace while others are smooth.

The sand crab lives in the ocean, specifically in the intertidal zone right at the area where waves wash up on the beach. This is called the swash, by the way, which is a great word. The sand crab burrows into the sand tail-first, using its strong rear legs, and during the time that there’s water over the sand, it unfurls its feathery antennae to filter tiny food particles from the water. When the wave goes out, it retracts its antennae and works on staying buried in the sand as the next wave rolls in.

In some species, males are very similar to females, but smaller. In other species, they’re tiny, barely 3 mm long at most, and even as adults they resemble larvae. The male finds a female and grabs hold of her leg, and there he stays. I tried to find out more about this, but it doesn’t look like the humble sand crab gets a lot of attention. If you’re interested in becoming a scientist who studies invertebrates and you want to spend a lot of time on the beach, the sand crab would make a good study buddy.

Lots of fish and birds eat sand crabs, and people do too. In many places they’re considered a delicacy and grilled as a snack. This isn’t surprising since they’re related to other crustaceans people like to eat, like crabs and lobsters.

Next, let’s learn about two strange sea slugs. We’ve talked about sea slugs a few times before, including in episodes 215 and 129, but there are a lot of species, with more being discovered pretty often.

Llewelly sent me a link ages ago about a sea slug that’s related to the sea bunny, which we talked about in the cutest invertebrates episode, 215. It’s called Phylliroe and doesn’t look like a little bunny or a slug. It looks like a fish.

Phylliroe grows a few inches long at most, or 5 cm, and the article Llewelly sent, which I’ve linked to in the show notes, points out that it’s about the size of a goldfish. Its rear end is shaped roughly like a fish tail, which it uses just like a fish tail to propel itself through the water. It’s probable that Phylliroe’s shape doesn’t have anything to do with disguising it, but instead is just the result of convergent evolution. A body streamlined to move through the water with minimal resistance is always going to be fish-shaped, because that’s why fish are shaped the way they are. The fish-like tail is also an efficient way to move through the water relatively quickly.

Phylliroe mostly eats tiny jellyfish, which it grabs with its small foot. It doesn’t need a big flat foot to glide on, since it doesn’t live on the sea floor like some of its relations, so over many, many generations its foot has become smaller and smaller until it’s just a little tiny foot near its mouth. It’s still sticky, though, which means jellies stick to it, which means it’s easier for Phylliroe to eat the jellies.

Phylliroe is mostly see-through, although you can see its digestive system. It also has two so-called horns, called rhinophores, that it probably uses to sense the chemical signature of its prey in the water. If you remember the sea bunny, its rhinophores look like bunny ears. Phylliroe’s look more like thick antennae or barbels. Phylliroe also exhibits bioluminescence, which is not a typical trait for a sea slug.

My brother Richard alerted me to another sea slug a while back, this one referred to as the Deadpool slug. The reason why it’s called the Deadpool slug is lost on me because I haven’t seen that movie or read the comic book, but the sea slug can separate its head from its body when it wants to, and it just grows a new body. The old body eventually dies instead of growing a new head.

The Deadpool slug is one of a type of sea slug that we talked about back in episode 129, about the blurry line between plants and animals. It eats algae and incorporates the algae’s chloroplasts into its body to use. Chloroplasts are what allows a plant to photosynthesize energy from sunlight, and the sea slug absolutely uses them for the same thing. Researchers think the Deadpool slug uses the energy from photosynthesis to regrow its body even though it has no digestive system after it separates its head from its body.

The big question is why the Deadpool slug wants to grow a new body in the first place. It doesn’t seem to be a defensive strategy if the sea slug is attacked. Instead, researchers think it often happens when the body contains too many parasites, specifically a type of tiny parasitic copepod, which is a crustacean. It might also happen after a predator bites a big chunk off the slug. Instead of hauling around a damaged body, the sea slug just jettisons the old body and regrows it.

Let’s finish with a recently solved octopus mystery that goes back almost 200 years. In 1838, the United States launched a scientific expedition throughout the Pacific Ocean and parts of the Atlantic that lasted four years. While it was mostly for exploration and mapping of places seldom or never visited by outsiders, the expedition also brought along a team of scientists and artists to document and study all the animals and plants they found. One of the things they found was an octopus.

The scientists didn’t fish the octopus up themselves. They actually bought several of them at a fish market in Brazil. It was red with little white spots all over it and not very big, although a dead octopus tends to shrink, especially when it’s out of water. The specimens were preserved in a jar of alcohol and brought back to the United States, where in 1852 they were studied by an expert on mollusks, Augustus Addison Gould. Octopuses are in the phylum Mollusca and Gould had examined lots and lots of octopuses. He decided this one was a new species and named it Callistoctopus furvus.

At some point the specimens were either lost or destroyed. Decades passed, then a century, then almost two centuries. Modern scientists thought Gould was probably wrong and that the little red octopus was one known from the Mediterranean Sea, Calistoctopus macropus. It’s red with little white spots, and has a mantle length only about 8 inches long, or 20 cm, although it has long arms and has been measured as almost five feet long, or 1.5 meters, if you include the arms. It lives in shallow water, where it spends a lot of time hunting for small animals that live in coral or in sea grass. It’s sometimes called the grass octopus.

Then a graduate student in Brazil named Manuella Dultra was studying octopuses, and part of her research involved talking to local fishers. They told her about an octopus that lived in shallow water and often buried itself in sand to hide, which is why they called it the sand octopus. They also said it was generally only seen when the wind blew from the east, and was more likely to be out and about during the new moon. Naturally Dultra wanted to find one. She asked the fishers to keep an eye out, and in 2013 she was given a freshly caught specimen.

The biologists at Dultra’s university identified the octopus as C. macropus, the grass octopus. Dultra wasn’t so sure. She noticed a lot of differences that seemed significant, and decided to do more research. She and her team gathered genetic material from specimens the local fishers caught, and sure enough, it was different from the grass octopus.

At the same time, researchers in Mexico had also found a sand octopus that they thought might be C. furvus. When Dultra compared her specimens’ DNA profile with the DNA profile from the Mexican octopus, it matched.

The discovery is still very new and isn’t accepted by all scientists yet, not until more studies are completed. The sand octopus appears to be rare, and once it’s definitely identified as its own species or subspecies and we learn more about it, we can do more to protect it.

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

Thanks for listening!


Episode 286: Chimerism, Mosaicism, and Venus the Cat



Thanks to Vaughn for suggesting this week’s episode topic about Venus the cat and her unusual coat pattern!

Further reading:

Mystery Cats of the World Revisited by Dr. Karl P.N. Shuker

Further listening:

Half-siders and sea monkeys Patreon episode from December 2018 (unlocked episode)

Venus the cat:

“Half-sider” birds can be spectacular:

Half-side chimeras are not just restricted to birds:

Ranger the “black lion” (photo by Peter Adamson, from this site which you should also read). Note the black patch on his right front leg:

Show transcript:

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

This week I had planned to release our updates episode, but I didn’t have time to finish it. The 2022 updates episode will run in September instead, since we’re doing Invertebrate August again this year!

Way back at least a year ago and possibly more, Vaughn suggested we do an episode about “rare two-tone animals like Venus the cat.” I put the suggestion on my list and totally forgot about it until today, when I saw it and thought, “hmm, who’s Venus the cat?”

If you don’t already know, Venus is a beautiful cat whose coloration is mostly what’s called tortoiseshell, meaning she has a mixture of colors on her body, in her case black and orange. But Venus’s face is completely black on one side with a green eye, but orange tabby on the other side with a blue eye. She also has a white bib and white on her paws.

Venus became famous after the family who adopted her as a stray in 2009 posted pictures of her online. Her coloration is so unusual that everyone wondered what caused it. The answer is that we aren’t exactly sure, but veterinarians and experts in cat genetics do have some pretty good ideas.

There are probably several things going on genetically with Venus that resulted in her interesting coloration. Her different-colored eyes are one result. When an animal has different-colored eyes, called heterochromia iridis, there are a number of possible causes, from an injury to one eye to various genetic conditions. Sometimes it’s not complete, meaning one eye may be partly a different color. It even happens in people sometimes, although it’s rare.

In Venus’s case, researchers think her heterochromia may be due to a gene that produces what’s called piebaldism. A piebald animal has white markings when an ordinary animal of the same species doesn’t have any white markings. Some animals who naturally have a white pattern may have the word pie or pied or just bald hidden in their name, such as the magpie and the bald eagle, because it used to mean just an outfit with different contrasting colors. In the story of the pied piper, the piper had on a suit made of different colors.

The white patches of a piebald animal actually don’t have any pigment, and if a white patch is over an eye, the eye may also lack pigment and appear blue. That’s pretty common in piebald or pinto horses or in some dog breeds with white markings. The piebald gene may also affect one or both eyes even if a white patch doesn’t cover the eye, which some researchers think may be the case in Venus. Her left eye is blue even though the left side of her face is orange tabby.

Venus’s unusual facial fur coloration may be due to a condition called chimerism. Chimerism happens long before an animal is born—in fact, it happens within a few hours after an egg cell is fertilized. I’ll do my best to explain it. A lot of the next section comes from a Patreon episode from 2018, and if you want to listen to the original I’ve unlocked it for anyone to listen to and put a link in the show notes.

As soon as an egg cell is fertilized, it starts to divide into more cells, which divide into more cells, which divide into more cells, and on and on. After a while, the groups of cells start to differentiate into parts of the body. Some cells become a heart, others become toes, and so on. Eventually there’s a whole finished baby ready to be born or hatched.

If there are two fertilized egg cells, they develop into two separate babies, which are fraternal twins that don’t necessarily look alike. Occasionally, a fertilized egg cell will split and each of the two resulting cells will start to develop separately. In that case, you get identical twins.

But very rarely, you start with two egg cells that should develop into fraternal twins—but for some reason, in those very first hours when each egg cell has only divided a few times, the egg cells fuse together. The cells continue to divide and develop into not two babies, but one that contains the genetic markers for both twins.

Since the resulting single baby has genes for both twins, sometimes it will show physical traits of both twins. For instance, if one twin’s genetic makeup would have developed into a green budgie, and the other twin’s genetic makeup would have developed into a blue budgie, you get a budgie that’s green on one side and blue on the other. Occasionally one side has the markings and coloration of a male, and the other side has the markings and coloration of a female. An animal with this kind of genetic anomaly is properly called a tetragametic chimera, but it’s often called a half-sider.

This doesn’t just happen in birds. Occasionally someone will come across a butterfly where the pair of wings on one side is colored like a male of that species and the pair of wings on the other side is colored like a female. Occasionally someone will adopt a kitten that’s one color on one side and a totally different color and pattern on the other side.

So I bet now you’re wondering if it happens in humans. Yes, it does! It happens occasionally in everything, including plants. Usually no one knows if a particular animal is a chimera because most of the time it doesn’t show. It’s only when it produces a spectacular coloration difference like in half-siders that anyone takes a second look.

Venus’s facial markings look a lot like those of a half-sider, but the markings on the rest of her body don’t, so she’s probably not a half-sider. That doesn’t mean she isn’t a chimera, since while all half-siders are chimeras, not all chimeras are half-siders. However, she might have a genetic mutation called mosaicism instead.

Mosaicism is similar to chimerism, but instead of being caused by two fertilized egg cells fusing together, it’s caused by a chromosomal mutation in one cell during the embryo’s very early development. The mutation is replicated as that cell divides, and then replicated in the divided cells, and so on, so that when the organism has finished developing into a baby, part of its body contains the mutation while the rest doesn’t. The part of the body with the mutation has a different genetic profile from the rest of the body.

Mosaicism can result in various physical conditions, but for the most part you can’t tell by looking if an organism exhibits mosaicism. But sometimes you can. In 1975 a lion cub was born in Glasgow Zoo in Scotland, and he had a big black patch on his chest and right front leg, with a less dark patch on his left hind leg. Since black lions are rumored to exist but have never been scientifically documented, or even photographed, this was a big deal. When Ranger the lion grew up he was introduced to several different females in hopes that he would sire cubs that also had black patches, or which were even black all over. Unfortunately Ranger seemed to be sterile and none of his mates got pregnant.

Ranger lived to be 22 years old but died before genetic testing became widespread and sophisticated. These days we know a lot more about big cat genetics and researchers are pretty sure Ranger’s black patches resulted from somatic mosaicism, which affected some of his skin cells. Since the right side of Venus’ face is solid black, some researchers think she might have a similar condition.

Whatever the cause or causes of Venus the cat’s coloration, though, one thing is for sure. She’s an absolutely beautiful cat!

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

Thanks for listening!