Monthly Archives: April 2017

Episode 012: The Wyvern, the Basilisk, and the Cockatrice



This week we range across the world to solve (sort of) the mystery of the wyvern, the basilisk, the cockatrice, and crowing snakes! Thanks to listener Richard E. for suggesting this week’s topic!

From left to right, or whatever since the three have been confused since at least the middle ages: the basilisk, the cockatrice, and the wyvern:

The king cobra, or maybe the basilisk:

The Egyptian mongoose/ichneumon, or maybe the cockatrice:

Basilisk!

Further reading:

Extraordinary Animals Revisited by Karl P.N. Shuker

Gode Cookery: The Cockentrice – A Ryal Mete

Show transcript:

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

This week’s episode was inspired by listener Richard E., who suggested the wyvern as a topic. He even attached some photos of wyverns in architecture around Leicester, England. I forgot to ask him if he lives in Leicester or just visits the city, but I looked at the photos and was struck by how much the wyvern resembles the cockatrice. Next thing I knew, I was scouring the internet for audio files of howling snakes. It all makes sense by the end.

Before we jump in, I’d like to apologize to a guy named Mike W. who is from Leicester. Mike, if by some crazy coincidence you’re listening, I am so, so sorry for the way I treated you in London in 1996. I was a jerk in my 20s, to put it mildly. You were such a great guy and I have felt awful ever since.

Okay, my oversharing out of the way, let’s talk about wyverns.

The word wyvern is related to the word viper, and originally that’s what it meant, but by the 17th century the word had lost its original meaning and was attached to a heraldic animal instead. The wyvern has been popular in heraldry since the middle ages.

In video games, the wyvern is usually a two-legged dragon with wings. In heraldry, it’s less dragonlike and more snakey, but it almost always has one pair of legs and one pair of wings. Frequently it wears a crown or has some sort of crest, and quite often its head looks a lot like a rooster’s.

The heraldic wyvern doesn’t seem to have ever been considered a real animal, but the cockatrice was. The cockatrice is usually depicted as a snakelike animal with a one pair of legs, one pair of wings, and a rooster-like head. You see the connection. But here’s the really confusing thing. The words cockatrice and basilisk were used more or less interchangeably as early as the 14th century. In fact, in the King James Version of the Bible, Isaiah 14 Verse 29 mentions a cockatrice, while the same verse in the English Revised Version uses the word basilisk instead.

Those two words don’t even sound alike. And if like me you grew up playing Dungeons & Dragons and reading books like Walter Wangerin Jr.’s The Book of the Dun Cow, you think of the cockatrice and the basilisk as totally different animals.

I’m going to talk about the basilisk first. Then I’ll come back to the cockatrice.

The basilisk has an old, old pedigree. A lot of online sources claim that Pliny the Elder was the first to describe the basilisk in his natural history in about 79 CE, but it was already a well-known animal by then. We know because the Roman poet Lucan, who died in 65 CE, makes reference to the basilisk twice in his epic poem Pharsalia in a way that implies his audience was completely with the animal’s supposed abilities.

The basilisk was supposed to be deadly—so deadly, in fact, that if a man on horseback speared a basilisk, the venom would run up the spear and kill not only the rider, but the horse too. That’s one of the stories Lucan references in his poem. Pliny also includes it in his natural history.

All the basilisk had to do was look at you and you’d die or be turned to stone. Birds flying in sight of a basilisk, no matter how high above it they were, would die in midair. The ground around a basilisk’s home was blighted, every plant dead and even the rocks shattered.

So what did the basilisk look like? Pliny describes it this way. I’ve taken this quote from a site called “The Medieval Bestiary,” which has a much clearer translation than Wikipedia’s and other sites that seem to have copied Wikipedia.

“It is no more than twelve inches long [30 cm] and has white markings on its head that look like a diadem. Unlike other snakes, which flee its hiss, it moves forward with its middle raised high.”

In other words, the basilisk was a snake, and not even a big snake. And according to Pliny, the weasel was capable of killing the basilisk. “The serpent is thrown into a hole where a weasel lives and the stench of the weasel kills the basilisk at the same time as the basilisk kills the weasel.”

In other words, someone would pick up a basilisk—which was supposed to be deadly to touch—and toss it down into a weasel’s burrow, and the weasel and the basilisk would both end up dead. Pliny, did you even think about what you were writing?

But back up just a little and the story starts to make more sense. We all saw “Rikki Tikki Tavi” as kids, right? The mongoose does look like a weasel. It’s also resistant to the king cobra’s venom and will prey on it and other snakes. The king cobra has an expandable hood with light-colored false eye spots on it. Its venom is so potent that it can kill a human in half an hour, and one of the final symptoms is paralysis, which may account for reports of the basilisk turning people to stone. King cobras can’t spit their venom, but many other cobras can. And most importantly, the weird notion that the basilisk moves forward with its middle raised high maybe explained by the king cobra’s habit of rearing up when threatened. It can still move forward when its front is raised.

But the king cobra is a big snake. Its average length is about twelve feet [3.7 m] and it can grow as long as 18 feet [5.5 meters]. Pliny describes a snake only a foot long [30 cm]. It’s possible Pliny just wrote the length wrong, conflated the cobra with some smaller snake, or scribes made a mistake copying the original writing. But the idea that the basilisk is actually a cobra seems cemented not by Pliny but by Lucan. Let me quote from book nine of Pharsalia, verses 849 to 853:

“There upreared his regal head

And frighted from his track with sibilant terror

All the subjects swam

Baneful, ere darts his poison. Basilisk.

In sands deserted king.”

A hissing poisonous crowned animal that rears up? It sounds like a king cobra to me. And the fact that stories about the basilisk mention its terrible hissing makes it even more likely.

The king cobra’s hiss sounds more like a growl. It has low-frequency resonance chambers in its windpipe that enhance and deepen the sound of its hiss. Here’s a clip of one, and I would not want to hear this coming from a snake the length of a truck:

[scary hissing]

At some point, though, the basilisk became a more lizard-like animal in western culture and took on rooster-like characteristics. The Venerable Bede, an English monk who lived from about the year 672 to 735, was the first to write down the story of the basilisk as many of us know it today. He said the basilisk was born from an egg laid by an old rooster. Hens do occasionally change sex and take on male characteristics, such as growing a pronounced crest and wattles, long tail feathers, and crowing. Sometimes they stop laying eggs but sometimes they don’t.

Incidentally, the other chickens take all this in stride and do not make a big deal about where the new rooster can go to the bathroom.

Other details got added to the basilisk story over the centuries. Sometimes the egg is described as round and leathery, which is true of many reptile eggs, and sometimes a toad is supposed to brood the egg until it hatches. Sometimes the rooster has to lay the egg at a certain time of year or moon phase. Whatever the circumstances surrounding the egg being laid, the animal that hatches from it is supposed to be a deadly serpent or lizard.

These are all details not described by Pliny. My guess is that the story of a rooster’s egg hatching into a deadly reptile was already a folktale in England when Pliny wrote his Natural History. The stories got conflated, probably by scholars who thought they described the same animal. That might also explain why the word cockatrice got grafted onto the rooster-egg legend. Let’s go back to learn about the cockatrice to figure out how.

The word cockatrice comes from a medieval Latin word that was a translation of the Greek word ichneumon from our old friend Pliny’s Natural History. It’s the same name used for the mongoose, although it can also mean otter. According to Pliny, the ichneumon will fight a snake by first covering itself with several coats of mud and letting it dry to form armor. Pliny also describes the ichneumon as waiting for a crocodile to open its jaws for the little tooth-cleaning birds to enter. When the crocodile falls asleep during the bird’s ministrations, the ichneumon runs down its throat and eats the croc’s intestines, killing it.

So the word that inspired the cockatrice wasn’t a snake at all. It was something that killed snakes and crocodiles. The confusion seems to be etymological. Ichneumon means something like “tracker” from a Greek word I can’t spell, track or footstep. Translated into Latin, it becomes cockatrix [probably spelled wrong] for the word for “tread.” Cockatrice is the corruption of cockatrix. But a cockatrice to English-speaking ears no longer sounds like any kind of snake-killing mammal. It sounds like the word cock, a rooster, combined with a slithery-sounding ending. So it’s very possible the confusion came from the word change mixed with confused tellings of the basilisk story. And when you consider that Chaucer referred to the basilisk as a basilicock, it’s easy to see that English speakers, at least, have been confusing the words and monsters for many centuries.

So it seems we’ve solved this mystery once and for all. The basilisk was a king cobra, the cockatrice was a mongoose, the wyvern was a fanciful heraldic animal, and we’re done.

But wait. Not so fast.

There are widely spread stories of snakes with combs and wattles that can crow like roosters. But those stories aren’t from England. They’re from Africa, with related stories in the West Indies.

The story goes that there’s a snake in east and central Africa that can grow up to twenty feet long [6 meters]. It’s dark brown or gray but has a scarlet face with a red crest that projects forward. Males also have a pair of face wattles and can crow, while females cluck like hens. Supposedly they have deadly venom and will lunge down from trees to attack humans who pass beneath.

At this point I got a little frantic and started trying to find out more about snake sounds. I didn’t think snakes could do anything but hiss, but it turns out that snake vocalizations are a lot more interesting than that.

In addition to the cobra’s deep hiss, bull snakes grunt. That’s how they get their name; they sound a little like cows. And at least one snake makes a sound no one would expect. That’s the Bornean cave racer, Orthriophis taeniurus grabowskyi, native to Sumatra and Borneo. It’s a lovely slender blue snake, not poisonous, also called the beauty ratsnake, and can grow some six feet long [1.8 m]. Some subspecies are kept as pets, but not grabowskyi as far as I know.

The snake has been known to science for a long time, but in 1980, a scientific exploration of the Melinau cave system in Borneo heard an eerie hoarse yowling in the dark, something like a cat. After the scientists no doubt wet their pants, they spotted a beauty ratsnake coiled on the cave floor. It was clearly making the sound.

I tried so hard to find audio of this snake. I really, really wanted to share it. But I’ve had no luck so we’ll just have to imagine it.

Most snakes don’t have vocal cords. That’s the name given to folds of tissue above the larynx. Snakes do have a larynx, and the bull snake, also called the pine snake or gopher snake, and native to the southeastern United States as far north as New Jersey, has a single vocal cord and a well-developed glottis flap. They’re noisy little guys for snakes. They grunt, hiss, and rattle their tails against dead leaves to scare potential predators away. Here’s a sample:

[hissing snake]

There are also stories from all around the world, from every region where snakes live, about snakes mimicking prey to draw it near. The stories come from people from every walk of life who are in position to observe nature closely: farmers, hutners, fishers, explorers—but unfortunately not any scientists. Not yet, anyway. Here’s one of the many examples given in Karl Shuker’s excellent book Extraordinary Animals Revisited, an excerpt I’ve chosen for reasons that will shortly become clear. It’s from an African report from 1856.

“The story of the cockatrice, so common in many parts of the world, is also found among the Demares. But instead of crowing, or rather chuckling like a fowl when going to roost, they say it bleats like a lamb. On its head like the guinea fowl it has a horny protuberance of a reddish color.”

It’s entirely possible that many snakes make sounds that mimic other animals, although whether they do it to lure prey near or whether it’s just a coincidence is another thing. But what about the whole issue about snakes not being able to hear airborne sounds? When I was a kid, I remember reading many books that said snakes can’t hear, they can only detect vibrations from the ground through their jaw bones.

Well, that’s not actually true. Snakes can hear sounds quite well, although their range of hearing is limited compared to mammals. In fact, a survey published in 2003 by the Quarterly Review of Biology confirms that snakes are more sensitive to airborne sounds than they are to ground-borne sounds. So it’s not that ridiculous to imagine a snake that makes sounds people might interpret as crowing or clucking.

But what about the wattles? A lot of snakes have head decorations, including many species of horned vipers that have modified scales above the eyes that really do look like horns. The rhinoceros viper has two or three horns on its nose. I couldn’t find any snakes with wattle-like frills, but it’s not out of the range of possibility. Plus, sometimes snakes don’t fully shed their skins and end up with bits and pieces of old skin left behind, which can stick out from the body.

Whether the African crowing snake legends have anything to do with the European legends of basilisks hatched from rooster eggs, I have no idea. The stories are different enough that I’m inclined to think they’re not related. Then again, reports of crowing snakes might have influenced the basilisk legend.

Incidentally, there’s a real-life lizard given the name basilisk, also called the Jesus lizard because it runs on water to escape predators. It lives in tropic rain forests in Central and South America and can run as fast as seven miles per hour [11 km/hr] on its hind legs, and when it reaches water it just keeps going. It’s big webbed feet and its speed keep it from sinking immediately.

The name ichneumon has been given to a few modern animals too: a type of mongoose that ancient Egyptians believed ate crocodile eggs, and various types of flies and wasps that parasitize caterpillars.

I was hoping that the cockatrice and wyvern would have lent their names to modern real animals too, but I couldn’t find any. But I did find something almost as good. In the middle ages there was a fancy dish called a cockatrice. I found this at a site called “Gode Cookery dot com” where good is spelled g-o-d-e. The site has it listed under cockentrice, with an N. I’ll put a link in the show notes.

Here’s a sample recipe, which the site took a book published in 1888 titled “Two Fifteenth Century Cookery-Books.”

“Take a capon, scald it, drain it clean, then cut it in half at the waist. Take a pig, scald it, drain it as the capon, and also cut it in half at the waist. Take needle and thread and sew the front part of the capon to the back part of the pig, and the front part of the pig to the back part of the capon, and then stuff it as you would stuff a pig. Put it on a spit and roast it, and when it is done, gild it on the outside with egg yolks, ginger, saffron, and parsley juice, and then serve it forth for a royal meat.”

A capon, incidentally, can mean either a castrated rooster or an old rooster. Either way, roast cockatrice sounds better than turducken, and way better than being the guy who has to throw the basilisk into the weasel den.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. We also have a Patreon if you’d like to support us that way.

Thanks for listening!


Episode 011: The Vampire Squid and the Vampire Bat



This week we’re going all goth in April for the vampire squid and the vampire bat. They’re so awesome I want to die.

The vampire squid looking all menacing even though it’s barely a foot long.

“I love you, vampire bat!!” “I love you too, Kate.”

Thanks for listening! We now have a Patreon if you’d like to subscribe! Rewards include patron-only episodes and stickers!

Show transcript:

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

I thought about waiting to run this episode in October, but that’s a really long way away. So we’ll have Halloween in April and talk about the vampire squid and the vampire bat.

The vampire squid has one of the coolest Latin names going, Vampyroteuthis infernalis, which means “vampire squid from hell.” It’s a deep-sea squid and until recently, not a lot was known about it. It was discovered in 1903 and originally classified as an octopus. Its body is about six inches long [15 cm], with another six inches or so of tentacles, which are connected with webbing called a cloak. Actually I’m not sure if scientists refer to this as a cloak, but if you’ve called your animal the vampire squid from hell, you can’t complain if podcasters, for instance, refer to web-connected octopus legs as a cloak.

So is it an octopus or a squid? It’s both, in a way. The vampire squid is the last surviving member of its own order, Vampyromorphida, which shares similarities with both.

The vampire squid’s color varies from deep red to velvety black. The inside of its cloak is black and the parts of its legs inside the cloak are studded with spines. Its beak is white. Basically the only thing this little guy needs to be the world’s ultimate goth is a collection of Morrissey albums.

It lives in the lightless depths of the ocean below 3,000 feet [914 meters]. There’s not a lot of oxygen down there so there aren’t very many predators. The vampire squid doesn’t need oxygen because it’s a vampire—or at least it can live and breathe just fine with oxygen saturations as little as 3%. Its metabolic rate is the lowest of any cephalopod.

The vampire squid doesn’t move a lot. It drifts gently, aided in buoyance because its gelatinous tissues are roughly the same density as seawater. Adults have two small fins sticking out from their mantle, which they flap to propel them through the water.

If something threatens a vampire squid, it brings its legs up to expose the spiny insides of its cloak and hide its body. If something really threatens a vampire squid, even though it doesn’t have ink sacs, it can eject a cloud of bioluminescent mucus, and can flash its photophores in a dazzling display of lights. These photophores are concentrated on the outside tips of its arms. If the end of an arm is bitten off, the vampire squid can regenerate it.

So we have a creepy-looking, if small, cephalopod that lives in the deep, deep sea called a vampire squid. WHAT. DOES. IT. EAT?

I hate to disappoint you, but the vampire squid eats crap. In fact, it eats the crap of animals that eat crap. There’s not a lot of food in the ocean depths. Mostly there’s just a constant rain of fish poop, algae, bits of scales and jellyfish, and other waste. Lots of little creatures live on this stuff and their poop joins the rain of barely-food that makes it down to the abyssal depths where the vampire squid waits.

The squid had two retractable filaments—not the same thing as the two feeding tentacles true squids have, but used for feeding. The filaments are extremely long, much longer than the vampire squid itself. It extends the filaments, organic detritus falls from above and sticks to them, and the vampire squid rolls the detritus up with mucus from its arm tentacles into little sticky balls and pops the balls into its mouth.

That’s not very goth. Or it might be incredibly goth, actually.

Most cephalopods only spawn once before they die. A 2015 paper in Current Biology reports that the vampire squid appears to go through multiple spawning phases throughout its life. It may live for a long time too, but we don’t know for sure. There’s still a lot we don’t know about the vampire squid.

Because squids and octopuses are soft bodied, we rarely find them in the fossil record. In 1982, though, a beautifully preserved octopus body impression was found in France in rocks dating to 165 million years ago. And guess what kind of octopus it turned out to be! Yes, it’s related to the vampire squid.

If the vampire squid is the kind of pensive goth who listens to The Smiths and reads Poe in cemeteries, the vampire bat is out clubbing with its friends, blasting Combichrist, and spending its allowance in thrift shops. There are three species of vampire bat, but they’re different enough from each other that each belongs to its own genus. They’re native to the Americas, especially tropical and subtropical environments, although they haven’t been found any further north than Mexico. And yes, vampire bats do actually feed on blood. It’s all they eat.

Vampire bats are small, active, and lightweight. They’re only about 3 ½ inches long [9cm] with a 7-inch wingspan [18 cm], and weigh less than two ounces [57 grams]. They live in colonies that consist of big family groups: a small number of males and many more females and their babies. Males without a colony hang out together and probably never clean up their apartments.

Vampire bats belong to the leaf-nosed bat family, and like other leaf-nosed bats they sleep during the day and hunt at night. But the vampire bat doesn’t actually have a nose leaf. That’s a structure that aids with echolocation, and vampire bats don’t need the high level echolocation ability that insect-eating bats do. They get by with a reduced ability to echolocate, but they have another highly developed sense that no other mammal has: thermoreception. They use it to determine the best place to bite their prey. The warmer, the better. That’s where the blood is.

The vampire bat also has good eyesight, a good sense of smell, and hearing that’s attuned to the sound of breathing. A bat frequently remembers the sound of an individual animal’s breathing, and returns to it to feed night after night. What vampire bats don’t have is a very good sense of taste. They don’t really need it. In fact, they don’t have the kind of bad food avoidance that every other mammal has. In a study where vampire bats were given blood with a compound that tasted bad and made them throw up, the next time they were offered the bad-tasting blood, they ate it anyway.

Most bats are clumsy on the ground. They’re built for flying and for hanging from perches. But vampire bats are agile. They crawl around and even run and jump with no problems.

Two species of vampire bat prey mainly on birds, while the third—the common vampire bat—feeds on mammals. Bird blood has a much higher fat content than mammal blood, which is higher in protein. But results of a study released in January 2017 found that hairy-legged vampire bats, which usually prey on large wild birds, had started feeding on domestic chickens as their wild prey became scarcer—and then they started feeding on human blood.

A vampire bat doesn’t suck blood. It makes a small incision with extremely sharp fangs and laps up the blood with its grooved tongue. It may even trim hair from the bite site first with its teeth. Its saliva contains an anti-coagulate called draculin that keeps the blood flowing. The bat doesn’t eat much, because let’s face it, it’s just a little guy. In order to hold more blood, as soon as it starts to feed its digestion goes into overdrive. Within some two minutes after it starts to eat, the bat is ready to urinate in order to get rid of the extra fluid so it can hold more blood. A feeding session may last about 20 minutes if the bat isn’t disturbed, and the bat may drink about an ounce of blood in all.

A vampire bat needs to eat at least every two days or it will starve. A bat that hasn’t found prey in two nights will beg for food from its colony mates, which often regurgitate a little blood for the hungry bat to eat. New mother bats may be fed this way by her colony for as much as two weeks after she’s given birth so that she doesn’t have to hunt. Baby vampire bats drink their mother’s milk just like any other mammal.

If a mother bat doesn’t return from hunting, other colony members will take care of her baby so it won’t die. Colony members groom each other and are generally very social. Even the male bats that aren’t part of the colony are allowed to roost nearby. Nobody fights over territory. These are nice little guys.

Vampire bats do sometimes carry rabies, but it’s pretty rare compared to infection rates in dogs. They are more dangerous to livestock than to humans. Attempts to kill off vampire bat colonies to stop the spread of rabies actually has the opposite effect, since bats from a disturbed colony will seek out another colony to join.

Vampire bats have considerable resistance to rabies and frequently recover from the disease, after which they’re immune to reinfection, and there’s some preliminary evidence to suggest that native human populations in areas where vampire bats are common may also have developed some resistance to rabies. Researchers hope that this finding will lead to better treatment of rabies in the same way that the draculin anticoagulant in vampire bat saliva led to advances in blood-thinning medications.

I like to imagine a vampire bat hanging out with a vampire squid. The bat would sip blood from a tiny wineglass and fidget with its jewelry while it tries to conversation. The squid would just stare at the bat. Then it would eat a globule of crap. The bat would pee on itself and the whole evening would just be a bust. Also, one of them would drown but if I can imagine a tiny wineglass I can imagine a tiny bat-sized bathysphere or something. Never mind.

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

Thanks for listening!


Episode 010: Electric Animals



This week’s episode is about electric animals! There are so many of them that I could only touch on the highlights.

We start with the electric eel. It’s not actually an eel but it is most definitely electric. This one has just read some disturbing fanfic:

The oriental hornet is a living solar panel:

The platypus’s bill is packed with electricity sensors. I couldn’t make this stuff up if I tried:

Amphisbaenids are not electric AS FAR AS WE KNOW. Bzzt.

Thanks for listening! We now have a Patreon if you’d like to subscribe! Rewards include patron-only episodes and stickers!

Show transcript:

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

This week we’re looking at electric animals! You’ve probably heard of the electric eel, but you may not know there are a lot of fish, insects, and even a few mammals that can sense or generate electric impulses. This is a re-record of the original episode with some updated information.

All animals generate electric fields in their nerves and the contracting of muscles. Animals that can sense these fields are called electroreceptive. An electroreceptive animal can find hidden prey without using its other senses.

To take that a step further, many electroreceptive animals can also generate weak electrical fields, usually less than a single volt—small electrical pulses or a sort of wave, depending on the species, that can give them information about their environment. Like a dolphin using echolocation, a fish using electro-location can sense where potential prey is, where predators, plants, and rocks are, and can even communicate with other fish of its same species. Of course, those same electric pulses can also attract electroreceptive predators. It’s hard being a fish.

But in some cases, the animal can generate an electric shock so strong it can stun or kill other animals. The most famous is the electric eel, so let’s start with that one.

The electric eel isn’t actually an eel. It’s a type of knife-fish related to carp and catfish. Some other species of knife-fish generate electric fields, but the electric eel is the only one that uses it as a weapon.

The electric eel is a weird fish even without the electric part. It can grow over eight feet long, or 2.5 m, lives in freshwater in South America, and gets most of its oxygen by breathing air at the surface of the water instead of through its gills. It has to surface for air about every ten minutes or it will drown. That’s a weird habit for a fish, but it makes sense when you consider that many electric eels live in shallow streams or floodplains with a tendency to dry up between rains. Oh, and electric eels frequently swim backwards.

A male electric eel makes a foam nest for females with his spit, and the female lays her eggs in it—as many as 17,000 eggs, although 1,200 is more common. The male defends the nest and hatchlings until the rainy season starts and the young electric eels can swim off on their own.

The electric eel has rows of some 6,000 specialized cells, called electrocytes, that act like batteries to store energy. When all the electrocytes discharge at the same time, the resulting shock can be as much as 860 volts, although it’s only delivered at about one amp. I have no idea what that means because I don’t understand electricity.

Since the electrocytes are all found in the animal’s tail, and electric eels are mostly tail, the fish will sometimes curl up and hold its prey against its tail to increase the shock it receives. This honestly sounds like something a villain from a superhero movie would do. The electric eel will also sometimes leap out of the water to shock an animal it perceives as a threat.

You do not want to be in the water when an electric eel discharges. It probably won’t kill you unless you have a heart problem, but it could stun you long enough that you drown. And if more than one electric eel discharges at the same time, the danger increases. There’s a River Monsters episode about electric eels that shows a whole bunch of them in water so shallow that they’re barely covered. Walking through that pond would probably be deadly. I also really love that show.

How does the electric eel not shock itself? Well, it probably does. All of its vital organs are in the front fifth of its body, and well insulated by thick skin and a layer of fat. But its discharges are extremely fast. Think taser, not sticking a fork in a wall socket, which by the way is something you should not do. The charge naturally travels away from its tail and into the nearest object, usually its prey.

There are three known species of electric eel, all of which live in the Amazon basin in South America. Two of the three species were only identified in 2019 after DNA studies of 107 specimens. One of the new species, Electrophorus voltai, can discharge up to 860 volts of electricity, higher than the well-known E. electricus. Researchers think E. voltai has evolved to generate higher jolts because it lives in the highlands of the Brazilian Shield, where the water is clear and doesn’t conduct electricity as well as the mineral-rich water in other electric eel habitats.

One last thing about the electric eel. It can shock people who touch it up to eight hours after it dies.

Most electric animals are fish since water conducts electricity well. Some other notable electric fish are the stargazer, a venomous bottom-dwelling ocean fish that generates shocks from modified eye muscles; the paddlefish; the electric catfish; and of course sharks.

Sharks are the kings of electroreceptive animals. Some sharks can sense voltage fluctuations of ten millionths of a volt. Sharks only sense electricity; they can’t generate it. But some of their cousins, the electric rays, can generate an electric shock equivalent to dropping a toaster in a bathtub, which by the way is another thing you shouldn’t do although why would you even have a toaster in the bathroom?

Scientists are only just discovering electric use in insects. It’s probably more widely spread than we suspect, and it’s used in ways that are very different from fish. The oriental hornet, for instance, converts sunlight into energy like a tiny flying solar panel. Researchers think the hornet uses that extra energy for digging its underground nests.

Flying insects generate a positive charge from the movement of air molecules, which is basically what static electricity is. It also happens to moving vehicles, and which is why you should touch the metal of your car to discharge any static electricity before pumping gasoline so you don’t spark a fire. This episode is full of safety tips. In the case of bees, this static charge helps pollen adhere to their bodies. You know, like tiny yellow socks stuck to a shirt you’ve just taken out of the dryer. When a bee lands on a flower, its charge also temporarily changes the electrical status of the flower. Other bees can sense this change and don’t visit the flower since its nectar has already been taken.

Spiderwebs are statoelectrically charged too, which actually draws insects into the web, along with pollen and other tiny air particles. This helps clean the air really effectively, in fact, so if you have allergies you should thank spiders for helping keep the pollen levels down. The webs only become electrically charged because the spider combs and pulls at the thread during the spinning process.

Only three living mammals are known to be electroreceptive. The South American Guiana dolphin has a row of electroreceptors along its beak, visible dots called vibrissal crypts. They’re basically pores where whiskers would have grown, except that marine mammals no longer grow whiskers. The vibrissal crypts are surrounded by nerve endings and contain some specialized cells and proteins. Researchers think the dolphins use electroreception to find fish and other prey animals in murky water when the animals are so close that echolocation isn’t very effective. A lot of toothed whales, including other dolphins, show these dots, and it’s possible that the Guiana dolphin isn’t the only species that is electroreceptive.

The platypus and its cousin the echidna are the other two electric-sensing mammals. These two are both such odd animals that they’re getting their own episode one day—and that episode is # 45! They are weird way beyond being the mammals that lay eggs deal. So I’ll just mention that their bills are packed with electroreceptors. The platypus in particular uses electroreception as its primary means of finding prey in the mud at the bottom of ponds.

There are undoubtedly more animals out there that make use of electrical fields in one way or another. One possible addition to the list, if it exists at all, is called the Mongolian death worm.

Nomadic tribes in the Gobi Desert describe a sausage-like worm over a foot long, or 30 cm, and the thickness of a man’s arm. Its smooth skin is dark red and it has no visible features, not even a mouth, which makes it hard to tell which end is the head and which is the tail. It squirms or rolls to move. It spends most of its life hidden in the sand, but in June and July it emerges, usually after rain, and can kill people and animals at a distance.

In his book The Search for the Last Undiscovered Animals, zoologist Karl Shuker discusses the death worm at length, including the possibility that it might be able to give electric shocks under the right conditions. Among the reports he recounts are some that sound very interesting in this regard, including that of a visiting geologist poking an iron rod into the sand, who dropped dead with no warning. A death worm emerged from the place where the geologist had been prodding the sand. I’m going to add “don’t poke an iron rod into the sand of the Gobi Desert” to my list of warnings.

The Gobi is a cold desert and has bitter winters, but it’s still a desert, which means it’s arid, which means the death worm probably isn’t a type of earthworm or amphibian—nothing that needs a lot of moisture to stay alive. On the other hand, two types of earthworms have recently been discovered in the Gobi, and there are a few amphibians, especially frogs, that have evolved to live in areas that don’t receive much rain. In episode 156, about some animals of Mongolia, we talk about the Mongolian death worm again if you want to know a little more. Some parts of the Gobi get more moisture than others and may be where the death worm lives.

Shuker suggests it might be a kind of amphisbaenid. Amphisbaenids are legless lizards that look more like worms than snakes. They move more like worms than snakes too, and spend a lot of their lives burrowing in search of worms or insects. No known species of amphisbaenid can generate electric shocks, but then again, only one of the over 2,000 known species of catfish generates electricity.

It’s not completely out of the realm of possibility that electrogenesis might develop in a reptile, assuming that’s what the death worm is. Sand isn’t a good conductor of electricity, but wet sand is. The death worm might ordinarily use weak electrical pulses to stun its small prey, but if it emerges after rain because its tunnels are temporarily flooded, it might feel vulnerable above ground and be more likely to discharge electrically as a warning when approached.

Of course, as always, until we have a body—until we know for sure that the Mongolian death worm is a real animal and not a folktale, we can’t do more than speculate. But it is interesting to think about.

As far as I can find, no living reptiles or birds show any electrical abilities akin to those in fish and other aquatic animals. But electroreceptors in fish were only discovered in the 1950s. There’s a lot we still don’t know. Always another mystery to solve!

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

Thanks for listening!


Episode 009: The Ivory-Billed Woodpecker



This week we take a look at (and listen to) the ivory-billed woodpecker and its close relative, the imperial woodpecker. Is it alive? Is it extinct? How can one innocent bird be the source of so much drama?

A pair of ivory-billed woodpeckers. Photo taken in 1935:

Frames from the alleged ivory-billed woodpecker video taken in 2004. Not super clear there, guys.

left to right: imperial woodpecker, ivory-billed woodpecker, and pileated woodpecker:

A pair of stuffed imperial woodpeckers:

A still from the 1958 video of a female imperial woodpecker. She’s so cute! Her crest bobs around as she moves.