Category Archives: invertebrates

Episode 174: MONSTER CEPHALOPODS!

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It’s a bonus monster month in June, because everything is awful and learning about monsters will take our minds off the awfulness. This week let’s learn about some mysterious stories from around the world that feature huge octopus or squid!

Further watching:

River Monsters episode about the Lusca

A colossal squid, up close to that gigantic eyeball:

Blue holes in the ocean and on land:

A giant Pacific octopus swimming:

The popular image of the kraken since the 1750s:

Show transcript:

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

Last week’s mystery bird got me thinking about how far away Halloween feels and how we haven’t really had a lot of monsters or mystery animals lately. So let’s have an extra monster month in June! We’ll start with a topic I’ve touched on in past episodes but haven’t covered in depth, three stories of GIANT OCTOPUS TYPE MONSTERS from around the world.

If you haven’t listened to episode 142, about octopuses, that ran last October, I recommend you listen to it for information about octopus biology and habits. This week we are all about the mysterious and gigantic octopuses.

Let’s jump right in with a monster from Japan, Akkorokamui. Its origins trace back to the folklore of the Ainu, a group of people who in the past mostly lived on Hokkaido, the second largest island in the country. These days they live throughout Japan. The story goes that a monster lives off the coast of Hokkaido, an octopus-like animal that in some stories is said to be 400 feet long, or over 120 meters. It’s supposed to swallow boats and whales whole. But Akkorokamui isn’t just an octopus. It has human features as well and godlike powers of healing. It’s also red, and because it’s so big, when it rises near the surface of the water, the water and even the sky look red too.

Akkorokamui is supposed to originally be from the land. A humongous red spider lived in the mountains, but one day it came down from the mountains and attacked a town, stomping down buildings as the earth shook. The villagers prayed for help, and the god of the sea heard them. He pulled the giant spider into the water where it turned into a giant octopus.

The problem with folktales, as we talked about way back in episode 17, about the Thunderbird, is that they’re not usually meant to be taken at face value. Stories impart many different kinds of information, especially in societies where writing isn’t known or isn’t known by everyone. Folktales can give warnings, record historical events, and entertain listeners, all at once. It’s possible the story of Akkorokamui is this kind of story, possibly one imparting historic information about an earthquake or tsunami that brought down a mountain and destroyed a town. That’s just a guess, though, since I don’t understand Japanese—and even if I did, the Ainu people were historically treated as inferior by the Japanese since their ancestors came from other parts of Asia, so many of their stories were never recorded properly. The Ainu people today have lost some of their historic cultural memories as they assimilated into Japanese society.

So we don’t know if Akkorokamui was once thought of as a real living animal, a spiritual entity, or just a story. There are a few reported sightings of the monster, but they’re all old and light on details. One account from the 19th century is supposedly from a Japanese fisherman who saw a monster with tentacles as big around as a grown man. It was so big that the fisherman at first thought he was just seeing reflected sunset light on the ocean. Then he came closer and realized what he was looking at—and that it was looking back at him from one enormous eye. He estimated it was something like 260 feet long, or 80 meters. Fortunately, instead of swallowing his boat, the monster sank back into the ocean.

Whether or not the folktale Akkorokamui was ever considered to be a real animal, it’s possible that some people who have seen enormous octopuses or squids have called them Akkorokamui. If you’ve listened to episode 74 about the colossal and giant squids, you may remember that both can grow over 40 feet long, or 12 meters, although the giant squid has longer arms while the colossal squid has a longer mantle in proportion to its arms. The two feeding tentacles that squids have are even longer than its arms when extended, which increases the longest measured length to 55 feet, or almost 17 meters. Both squid species are deep-sea animals that are rarely seen near the surface. But both are usually pink or red in color. A squid that big would terrify anyone, especially if they’re fishing in a small boat.

Another octopus-like sea monster is the lusca, this one from Caribbean folklore. The Caribbean Sea is part of the Atlantic Ocean outside of the Gulf of Mexico. Within the Caribbean Sea are thousands of islands, some tiny, some large, including those known collectively as the West Indies. Many reports of the lusca come from the Bahamas, specifically the so-called blue holes that dot many of the islands.

Blue holes are big round sinkholes that connect to the ocean through underground passages. Usually blue holes contain seawater, but some may have a layer of fresh water on top. Some blue holes are underwater while some are on land. The islands of the Bahamas aren’t the only places where blue holes exist. Australia, China, and Egypt all have famous blue holes, for instance, but they’re not uncommon across the world.

Blue holes form in land that contains a lot of limestone. Limestone weathers more easily than other types of rock, and most caves are formed by water percolating through limestone and slowly wearing passages through it. This is how blue holes formed too. During the Pleistocene, when the oceans were substantially lower since so much water was locked up in glaciers, blue holes formed on land, and many of them were later submerged when the sea levels rose. They can be large at the surface, but divers who try to descend into a blue hole soon discover that it pinches closed and turns into twisty passages that eventually reach the ocean, although no diver has been able to navigate so far. Many, many divers have died exploring blue holes.

Andros Island in the Bahamas has 178 blue holes on land and more than 50 in the ocean surrounding the island. It’s also the source of a lot of lusca reports.

So what does the lusca look like? Reports describe a monster that’s sharklike in the front with long octopus-like legs. It’s supposed to be huge, with an armspan of 75 feet, or 23 meters, or even more. The story goes that the tides that rise and fall in the blue holes aren’t due to tides at all but to the lusca breathing in and out.

But people really do occasionally see what they think is a lusca, and sometimes people swimming in a blue hole are dragged under and never seen again. Since blue holes don’t contain currents, it must be an animal living in the water that occasionally grabs a swimmer.

The problem is, there’s very little oxygen in the water deep within a blue hole. Fish and other animals live near the surface, but only bacteria that can thrive in low-oxygen environments live deeper. So even though the blue holes are connected to the ocean, it’s not a passage that most animals could survive. Larger animals wouldn’t be able to squeeze through the narrow openings in the rock anyway.

But maybe they don’t need to. Most blue holes have side passages carved out by freshwater streams flowing into the marine water, which causes a chemical reaction that speeds the dissolving of limestone. Some blue holes on Andros Island have side passages that extend a couple of miles, or several kilometers. It’s possible that some of these side passages also connect to the ocean, and some of them may connect to other blue holes. Most of the blue holes and side passages aren’t mapped since it’s so hard to get equipment through them.

But as far as we know, there is no monster that looks like a shark with octopus-like legs. That has to be a story to scare people, right? Maybe not. The largest octopus known to science is the giant Pacific octopus, which we talked about in episode 142. The largest ever measured had an armspan of 32 feet, or almost 10 meters. It lives in deep water and like all octopuses, it can squeeze its boneless body through quite small openings. When it swims, its arms trail behind it something like a squid’s, and it moves headfirst through the water. A big octopus has a big mantle with openings on both sides for the gills and an aperture above the siphon. The mantle of the octopus could easily be mistaken for the nose of a shark, with a glimpse of the openings assumed to be its partially open mouth. And a large octopus could easily grab a human swimming in a blue hole and drag it to its side passage lair to eat. Big octopuses eat sharks.

The giant Pacific octopus lives in the Pacific, though, not the Atlantic. If the lusca is a huge octopus, it’s probably a species unknown to science, possibly one whose mantle is more pointy in shape, more like a squid’s. That would make it resemble a shark’s snout even more.

Finally, let’s look at a monster many of us are already familiar with, the kraken. Many people think the legend of the kraken was just an exaggerated description of the giant squid. But that’s actually not the case.

The kraken is a Scandinavian monster that dates back to at least the 13th century, when a Norwegian historian wrote about it. That historian, whose name we don’t know, said it was so big that sailors took it for land while it was basking at the surface. The sailors would stop to make camp on what they thought was an island, but when they lit a campfire the kraken submerged and drowned the sailors. It could swallow ships and whales whole.

Nothing about the story mentions squid-like arms until the 1750s when a bishop called Erik Pontoppidan wrote about the kraken. Pontoppidan repeated the story of the kraken appearing island-like and then submerging, but said that it wasn’t the submerging that was so dangerous, it was the whirlpool the kraken caused as it submerged. I’d say that’s just a little bit of hair-splitting, because those sailors were in trouble either way. But Pontoppidan also said that the kraken could pull ships down into the ocean with its arms, which immediately made people think of squid and octopuses of enormous size. The idea of a stupendously large squid or octopus with its arms wrapped around a ship made its way into popular culture and remains there today.

The kraken story was probably inspired by whales, which of course were well known to Scandinavian sailors and fishers. It also might have been inspired by remote islands that are so low in the water that they’re sometimes submerged.

All that aside, could a cephalopod of enormous size actually reach out of deep water and grab the railing or masts of a ship or boat? Actually, it can’t do that, no matter how big or small. Remember that cephalopods have no skeleton, and while their arms are remarkably strong, it takes a whole lot of energy to lift a body part out of the water. We don’t notice this when swimming because our bodies are naturally buoyant especially with our lungs filled with air, and we have bones to give our bodies structure. An octopus spends most of its life supported by the water. When it comes out of the water, it stays very flat to the ground. It can only lift an arm out of the water if it can brace itself against something.

So the dramatic movie scenes where massive kraken arms suddenly shoot out of the water to seize a ship are just fantasy. But an octopus could grab onto the side of a ship with its suction cups and even heave itself onboard that way, potentially capsizing it. So that’s something fun to think about the next time you’re in a boat.

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. If you like the podcast and want to help us out, leave a rating and review on Apple Podcasts or wherever you listen to podcasts. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way.

Thanks for listening!

Episode 169: The Tarantula!

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This week let’s learn about my nemesis (in Animal Crossing: New Horizons, at least), the tarantula!

Further reading:

Tarantulas inspire new structural color with the greatest viewing angle

My character in Animal Crossing (and the shirt I made her–yes, I know tarantulas are arachnids, not insects, but I think the shirt is funny):

Boy who is not afraid of a tarantula:

The Goliath birdeater and a hand. Not photoshopped:

The cobalt blue tarantula:

The Gooty sapphire ornamental:

The Singapore blue tarantula:

The painting by Maria Sibylla Merian that shows a tarantula eating a hummingbird (lower left):

The pinktoe tarantula that Merian painted:

The great horned baboon (not actually a baboon):

Show transcript:

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

Just over two weeks ago I got a Nintendo Switch Lite and I’ve been playing Animal Crossing New Horizons a lot. I’m having a lot of fun with it, so let’s have a slightly Animal Crossing-themed episode and learn about my nemesis in the game, the tarantula.

A tarantula is a spider in the family Theraphosidae, and there are something like twelve hundred species. They live throughout much of the world, including most of the United States, Central and South America, Africa and some nearby parts of southern Europe and the Middle East, most of Asia, and Australia.

The tarantula is a predator, and while it can spin silk it doesn’t build a web to trap insects. It goes out and actively hunts its prey. It uses its silk to make a little nest that it hides in when it’s not hunting. Some species dig a burrow to live in but will line the burrow with silk to keep it from caving in and, let’s be honest, probably to make it more comfortable. The burrow of some species is relatively elaborate, for example those of the genus Brachypelma, which is from the Pacific coast of Mexico. Brachypelma’s burrow has two chambers, one reserved for molting its exoskeleton, one used for everyday activities like eating prey. Brachypelma usually sits at the entrance of its burrow and waits for a small animal to come near, at which point it jumps out and grabs it.

Many species of tarantula live in trees, but because they tend to be large and heavy spiders, falling out of a tree can easily kill a tarantula. But also because they’re large and heavy spiders, they can’t hold onto vertical surfaces the way most spiders do, using what’s called dynamic attachment. Most spiders have thousands of microscopic hairs at the end of their legs that allow it to hold onto surfaces more easily. But no matter what you learned from Spider-Man movies and comics, this doesn’t work very effectively for heavier animals, and many tarantulas are just too heavy. The tarantula does have two or three retractable claws at the end of its legs, but it’s also able to release tiny filaments of silk from its feet if it starts to slip, which anchors it in place.

Like other spiders, the tarantula has eight legs. It also has eight eyes, but the eyes are small and it doesn’t have very good vision. Most tarantulas are also covered with little hairs that make them appear fuzzy. These aren’t true hairs but setae [pronounced see-tee] made of chitin, although they do help keep a tarantula warm. They also help a tarantula sense the world around it with a specialized sense of touch. The setae are sensitive to the tiniest air currents and air vibrations, as well as chemical signatures.

Many species of tarantula have special setae called urticating spines that can be dislodged from the body easily. If a tarantula feels threatened, it will rub a leg against its abdomen, dislodging the urticating spines. The spines are fine and light so they float upward away from the spider on the tiny air currents made by the tarantula’s legs, and right into the face of whatever animal is threatening it. The spines are covered with microscopic barbs that latch onto whatever they touch. If that’s your face or hands, they are going to make your skin itch painfully, and if it happens to be your eyeball you might end up having to go to the eye doctor for an injured cornea. Scientists who study tarantulas usually wear eye protection.

One species of tarantula famous for its urticating spines also happens to be the heaviest spider known, and almost the biggest. It’s the Goliath birdeater, which I’m pretty sure we talked about in the spiders episode in October of 2018. Its leg span can be as much as a foot across, or 30 cm, and it can weigh as much as 6.2 ounces, or 175 grams. It’s brown or golden in color and lives in South America, especially in swampy parts of the Amazon rainforest. It’s nocturnal and mostly eats worms, large insects, other spiders, amphibians like frogs and toads, and occasionally other small animals like lizards and even snakes. And yes, every so often it will catch and eat a bird, but that’s rare. Birds are a lot harder to catch than worms, especially since the Goliath birdeater lives on the ground, not in trees. It’s considered a delicacy in northeastern South America, by the way. People eat it roasted. Apparently it tastes kind of like shrimp.

Most tarantulas from the Americas, known collectively as New World tarantulas, are mostly brown in color. Some have legs striped with rusty red, black, or white, but for the most part they’re all brown. But the Old World tarantulas found in the rest of the world are often more colorful, including many species that are blue. Not that slate gray color sometimes called blue but BRIGHT BLUE. The color isn’t caused by a pigment but by crystalline nanostructures in the exoskeleton, and researchers have recently found that different species of tarantula have evolved similar blue nanostructures independently—at least eight different times. Researchers have been studying the nanostructures and recently managed to replicate it with a nano-3D printer. Eventually they hope that the nanostructure color can replace toxic synthetic dyes for many materials. In addition to not being toxic, nanostructure colors don’t fade.

No one’s sure why so many tarantulas are blue, though. Remember that tarantulas don’t have very good eyesight so they probably don’t depend on color to attract a mate, at least as far as we know.

One blue tarantula is called the cobalt blue tarantula, which lives in the rainforests of southeast Asia. It spends most of its time in deep burrows except when it’s hunting. It has a legspan of about five inches, or 13 cm, and has blue legs and a gray body. Another is the Gooty sapphire ornamental, which is bright blue with a pattern of white on its body and legs. It’s from India, has a legspan of 8 inches, or 20 cm, and is critically threatened due to habitat loss. A third is the Singapore blue, which has a legspan of 9 inches, or 23 cm, and has bright blue legs and a brown or gold body. All these species, and many others, are bred in captivity as pets even though all tarantulas have venom that can cause painful reactions in humans.

Tarantula venom varies from species to species, and as with other venomous animals, researchers have been studying its venom to find potential medical uses, especially painkillers. The venom of some tarantulas targets nerve cells the same way that capsaicin does in hot chili peppers, resulting in a burning sensation. Australian tarantulas produce venom that contains a protein that is effective at killing insects if they eat it, not just if it’s injected, which has led to studies about using the protein to produce more eco-friendly insecticides for crops.

Results of a brand new study, published just a few weeks ago as this episode goes live, finds that the venom of the Chinese bird spider can be adapted to act as a strong pain reliever. It has similar results to morphine and related painkillers without side effects or risk of addiction. It still has to go through a number of clinical trials before it can be made into a drug for doctors to prescribe, but so far the results are promising.

Female tarantulas are usually a little larger than males, although the male may have longer legs. The female usually lays eggs once a year and guards her egg sac for six to eight weeks. She may also guard the babies after they hatch until they leave the nest. Male tarantulas typically don’t live very long compared to females, which can live for several decades in captivity—sometimes up to forty years.

The tarantula molts its exoskeleton periodically as it grows, several times a year for young spiders. Fully grown tarantulas may molt once a year or so. Molting is how a spider replaces lost or injured limbs and how it replaces its urticating spines.

So, in episode 90, about spiders, we talked about a lot of mystery spiders, including giant ones. It’s possible there are larger tarantula species out there than the Goliath birdeater, since new species of tarantula get discovered almost every year. But it’s not likely to be much larger, since as we also discussed in episode 90, the size of a spider or other terrestrial invertebrate is limited by its ability to absorb oxygen.

But there is another mystery associated with tarantulas that doesn’t have to do with their size, although it’s not a mystery that will keep you up at night. There’s a painting of tarantulas by Maria Sibylla Merian, a German artist who lived in the late 17th and early 18th centuries, that shows one tarantula eating a hummingbird. That’s actually how the Goliath birdeater and its close relations got the name birdeater. Merian painted tropical insects and other animals and plants, and unlike many of the artists of her day she was painstaking in her details and was a close observer of nature. She was also a leading entomologist back when that field was in its infancy and women weren’t supposed to do much of anything except have babies. She painted the birdeater tarantula during a trip to Dutch Surinam in South America, sometime between September 1699 and June 1701 when she returned home. It appeared in a book she published in 1705 with the help of her two grown daughters, and her paintings and notes were the first that many people in Europe had ever heard about animals and plants of the Americas. But while Merian’s paintings were meticulous in their details, no one was actually sure which tarantula she had painted.

The problem wasn’t her painting, but confusion about what species of tarantula actually live in northern South America. Carl Linnaeus described the first species of the genus Avicularia in 1758, but the tarantulas he studied, and the ones later assigned to Avicularia, were not actually all related. A few years ago, a team of spider experts in Brazil decided to figure it all out once and for all.

The team studied every specimen collected from the area, both newly collected and old ones in museums around the world. Previously, Avicularia had contained 49 species, but the team changed that to just 12—and three of those 12 were ones new to science. They separated the other species out into three new genera. One of the new species was named after Merian, Avicularia merianae.

The species Merian illustrated is the pinktoe tarantula, Avicularia avicularia, which is brown or black except for the tips of its legs, which are pinkish. Its venom is weak and its legspan is about six inches, or 15 cm. It lives in trees where it ambushes small animals, usually insects, although it will also scavenge already dead animals it finds. Researchers think this is probably the case with Merian’s painting of the tarantula eating a hummingbird, since the pinktoe is too small and weak to kill a hummingbird itself.

Some species of tarantula makes a sort of soft hissing or rattling sound if it feels threatened, called stridulating. Some other spiders and other animals make a similar noise. The tarantula rubs the hairs of its legs together to produce the noise, which sounds like this:

[tarantula stridulating sound]

The tarantula making that sound is called the great horned baboon, which is from Zimbabwe and Mozambique in southern Africa and is not a baboon but a spider. Its legspan is about six inches, or 15 cm, and it’s a very pretty black or gray with a white pattern over most of its body and legs, and a brown or tan pattern on its abdomen. But the most remarkable thing about it is the so-called horn. This is a black horn-like structure that grows from the spider’s carapace. No one is sure what the horn is for. No one except the tarantula, that is.

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. If you like the podcast and want to help us out, leave a rating and review on Apple Podcasts or wherever you listen to podcasts. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way.

Thanks for listening!

Episode 168: The Longest Lived

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This week let’s take a look at some animals (and other living organisms) that live the longest!

This isn’t Methuselah itself (scientists aren’t saying which tree it is, to keep it safe), but it’s a bristlecone pine:

The Jaya Sri Maha Bodhi, a sacred fig tree in Sri Lanka, planted in 288 BCE by a king:

Some trees of the quaking aspen colony called Pando:

Glass sponges (this one’s called the Venus Flower Basket):

Further reading:

Glass sponge as a living climate archive

Show transcript:

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

This week we’re going to look at the world’s longest lived animals and other organisms. We’re straying into plant territory a little bit here, but I think you’ll agree that this is some fascinating information.

The oldest human whose age we can verify was a French woman who lived to be 122 years old, plus 164 days. Her name was Jeanne Calment and she came from a long-lived family. Her brother lived to the age of 97. Jeanne was born in 1875 and didn’t die until 1997. But the sad thing is, she outlived her entire family. She had a daughter who died of a lung disease called pleurisy at only 36 years old—in fact, on her 36th birthday—and her only grandson died in a car wreck in his late 30s. Jeanne remained healthy physically and mentally until nearly the end of her life, although she had always had poor eyesight.

It’s not all that rare for humans to live past the age of 100, but it is rare for anyone to live to age 110 or beyond. But other animals have average lifespans that are much, much longer than that of humans.

In episode 163 we talked about the Greenland shark, which can live for hundreds of years. The oldest Greenland shark examined was possibly as old as 512 years old, and the sharks may live much longer than that. It’s actually the longest-lived vertebrate known.

No one’s sure which terrestrial vertebrate lives the longest, but it’s probably a tortoise. Giant tortoises are famous for their longevity, routinely living beyond age 100 and sometimes more than 200 years old. The difficulty of verifying a tortoise’s age is that to humans, tortoises all look pretty much alike and we don’t always know exactly when a particular tortoise was hatched. Plus, of course, we know even less about tortoises in the wild than we do ones kept in captivity. But probably the oldest known is an Aldabra giant tortoise that may have been 255 years old when it died in 2006. We talked about giant tortoises in episode 95.

But for the really long-lived creatures, we have to look at the plant world. The oldest individual tree whose age we know for certain is a Great Basin bristlecone pine called Methuselah. Methuselah lives in the Inyo National Forest in the White Mountains in California, which of course is on the west coast of North America. In 1957 a core sample was taken from it and other bristlecone pines that grow in what’s called the ancient bristlecone pine forest. Many trees show growth rings in the trunk that make a pattern that’s easy to count, so the tree’s age is easy to determine as long as you have someone who is patient enough to count all the rings. Well, Methuselah was 4,789 years old in 1957. It probably germinated in 2833 BCE. Other trees in the forest were nearly as old, with at least one possibly older, but the sample from that older tree is lost and no one’s sure where the tree the sample came from is.

Another bristlecone pine, called the Prometheus Tree, germinated even earlier than Methuselah, probably in 2880 BCE, but it’s now dead. A grad student cut it down in 1964, possibly by accident—stories vary and no one actually knows why he cut the tree down. The bristlecone pine is now a protected species.

There are other trees estimated to be as old as Methuselah. This includes a yew in North Wales that may be 5,000 years old and is probably at least 4,000 years old, and a cypress in Iran that’s at least 2,000 years old and possibly 5,000 years old. Sequoyahs from western North America, baobabs from Africa, and kauri trees from New Zealand are all documented to live over a thousand years and possibly many thousands of years.

In at least one case, a sacred fig tree in Sri Lanka, we know exactly when the tree was planted. A Buddhist nun brought a branch of the original sacred fig tree, the one that the Buddha was sitting under when he achieved enlightenment, to Sri Lanka and presented it to King Devanampiya Tissa. He planted the branch in the royal park in 288 BCE, where it grew into a tree which remains in the park to this day, more than 2,000 years later. It’s cared for by Buddhists monks and people come from all over Sri Lanka to visit the tree. If this sounds a little too good to be true, the easiest way to grow a sacred fig is to use a cutting from another tree. The cutting will root and grow into a new tree.

Not all trees are individuals. You may not know this and I didn’t either until recently. Some trees grow as colonies. The most well known tree colony is called Pando, made up of quaking aspens that live in Utah in North America. While the individual trees are only around 130 years old on average, Pando itself has been alive for an estimated 80,000 years. Each tree is a male clone and all the trees are connected by a root system that covers 106 acres, or 43 hectares. Because its root system is so huge and deep, Pando is able to survive forest fires that kill all other trees. Pando’s trees die, but afterwards the roots just send up shoots that grow into new trees. Researchers estimate that it’s been 10,000 years since Pando’s trees actually flowered. Unfortunately, Pando is currently threatened by humans stopping the forest fires that otherwise would kill off rival trees, and threatened by grazing livestock that kill off young trees before they can become established.

Pando isn’t the only quaking aspen colony known, though. There are a number of smaller colonies in western North America. Researchers think it’s an adaptation to frequent forest fires and a semi-arid climate that makes it harder for seedlings to grow. Quaking aspens that live in northeastern North America, where the climate is much wetter, grow from seeds instead of forming colonies.

Other species of tree form colonies too, including a spruce tree in Sweden whose root system dates to nearly 10,000 years ago and a pine colony in Tasmania that is about the same age but with individual trees that are themselves 3,000 years old. Not all long-lived plant colonies are trees, though. A colony of sea grass in the Mediterranean may be as much as 200,000 years old although it may be only 12,000 years old, researchers aren’t sure.

I could go on and on about long-lived plants, but let’s get back to the animals. If the Greenland shark is the longest lived vertebrate known, what’s the longest lived invertebrate? Here’s your reminder that a vertebrate is an animal with some form of spine, while an invertebrate has no spine.

Many invertebrates that live in the ocean have long lifespans. Corals of various kinds can live for thousands of years, for instance. The ocean quahog, a type of clam that lives in the North Atlantic Ocean, grows very slowly compared to other clams. It isn’t fully mature until it’s nearly six years old, and populations that live in cold water can live a long time. Sort of like tree rings, the age of a clam can be determined by counting the growth rings on its shell, and a particular clam dredged up from the coast of Iceland in 2006 was discovered to be 507 years old. Its age was double-checked by carbon-14 dating of the shell, which verified that it was indeed just over 500 years old when it was caught and died. Researchers aren’t sure how long the quahog can live, but it’s a safe bet that there are some alive today that are older than 507 years, possibly a lot older.

But the invertebrate that probably lives the longest is the glass sponge. It’s found throughout the world’s oceans, but is especially common in cold waters of the Northern Pacific and Antarctic. It usually grows up to about a foot tall, or 30 cm, although some species grow larger, and is roughly shaped like a vase. Most species are white or pale in color. In some places the sponges fuse together to form reefs, with the largest found so far 65 feet tall, or 20 meters, and nearly four and a half miles long, or 7 km.

The glass sponge is a simple creature with a lattice-like skeleton made of silica covered with porous tissue. It anchors itself to a rock or the ocean floor, frequently in deep water, and as water flows through the openings in its body, it filters microscopic food out. So it basically lives a very slow, very plant-like existence.

One glass sponge, Monorhaphis chuni, anchors itself to the sea floor with a long basal spicule that looks like a stem. This stem can be over nine feet long, or 3 m. It needs to be long because it lives in deep water where there’s a lot of soft sediment at the bottom. In 1986 the skeleton of a dead Monorhaphis was collected from the East China Sea so it could be studied. Since a glass sponge adds layers of skeleton to its basal spicule every year as it grows, you guessed it, the layers can be counted just like tree rings—although it requires an electron microscope to count since the layers are very small. The sponge was determined to be about 11,000 years old when it died. Researchers are able to determine local ocean temperature changes from year to year by studying the rings, just as tree rings give us information about local climate.

Let’s finish with something called an endolith. An endolith isn’t a particular animal or even a group of related animals. An endolith is an organism that lives inside a rock or other rock-like substance, such as coral. Some are fungi, some lichens, some amoebas, some bacteria, and various other organisms, many of them single-celled and all of them very small if not microscopic. Some live in tiny cracks in a rock, some live in porous rocks that have space between grains of mineral, some bore into the rock. Many are considered extremophiles, living in rocks inside Antarctic permafrost, at the tops of the highest mountains, in the abyssal depths of the oceans, and at least two miles, or 3 km, below the earth’s surface.

Various endoliths live on different minerals, including potassium, sulfur, and iron. Some endoliths even eat other endoliths. We don’t know a whole lot about them, but studies of endoliths found in soil deep beneath the ocean’s floor suggest that they grow extremely slowly. Like, from one generation to the next could be as long as 10,000 years, with the oldest endoliths potentially being millions of years old—even as old as the sediment itself, which dates to 100 million years old.

That is way older than Jeanne Calment and all those trees.

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. If you like the podcast and want to help us out, leave a rating and review on Apple Podcasts or wherever you listen to podcasts. We also have a Patreon at patreon.com/strangeanimalspodcast if you’d like to support us that way.

Thanks for listening!

Episode 160: Two Rare Bees

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I feel like I’m coming down with a cold, so here’s a short episode that I can get finished before I start to croak like a bullfrog or a raven. It’s time for some astonishing bees! Thanks to Richard J. for the suggestion!

Wallace’s giant bee compared to an ordinary honeybee:

Osima avosetta makes her nest out of flower petals:

Show transcript:

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

I think I’m coming down with a cold, so to avoid another potential bullfrog and raven episode where I croak to you for fifteen minutes in an increasingly hideous voice, this week we’ll have a short episode that I can get ready to go quickly. Let’s learn about two types of interesting bee!

The first is an insect called Wallace’s giant bee, or the giant mason bee, which was suggested by Richard J. That’s the Richard J who isn’t my brother. Richard sent me an article about Wallace’s giant bee, and it’s amazing.

Wallace’s giant bee (Megachile pluto) is an all-black bee that lives in Indonesia and is the largest species of bee known. The female is larger than the male, which is barely an inch long, or about 2.3 cm. The female’s body is over an inch and a half long, or 4 cm, with a wingspan of about three inches, or 7.5 cm. The female also has huge jaws that she uses to burrow into termite nests, and to keep the termites from evicting her and her sisters, she lines the galleries inside with tree resin. The female gathers the resin from specific types of trees, forms it into large balls, and uses her jaws to carry the ball back to her nest.

The bee was described in 1858 and found in forests on three islands in Indonesia. But palm oil plantations have destroyed so much of the forests that it was thought to be extinct. Then, in 1981, an entomologist found six nests and determined that it was still hanging on—but that was the last anyone saw of it until 2018 when two specimens were listed on eBay. That prompted a scientific expedition.

In January 2019, a small team of scientists searched two of the islands where the bee had once been known to live. They searched every termite nest they could find without luck, but when they were about ready to give up and return home, they searched one last termite nest. It was in a tree about eight feet off the ground, or 2.4 meters. And one of the scientists spotted a giant-bee-sized hole in the nest. He poked around the hole with a blade of grass, and a single female Wallace’s giant bee emerged from the hole.

The scientists caught the bee and observed her for a short time before releasing her so she could return to her nest. The lead scientist, an entomologist named Eli Wyman, said, “She was the most precious thing on the planet to us,” which is exactly how a good entomologist should feel when rediscovering the world’s biggest bee.

Hopefully Wallace’s giant bee will be protected now that more people know how special it is.

Our other interesting bee is named Osima avosetta, and it’s also a type of mason bee. Mason bees use mud, resin, or other materials to make or line their nests. In the case of O. avosetta, she uses flower petals to create nests for her babies. O. avosetta is a solitary bee instead of one that lives in colonies. It lives in southwest Asia and parts of the middle east. The female digs a small hole in the ground and lines it with overlapping flower petals, which she sticks together with mud, then pastes more petals on top of the mud. One hole may have a number of chambers in it, or the bee may make separate nests for each egg. She lays a single egg in each chamber, generally a total of about ten eggs. She makes a mixture of nectar and pollen and leaves it next to the egg, and when all the chambers are full she seals the top of the nest by folding petals over it and covering them with more mud. The mud hardens and protects the eggs from weather and from drying out. When the babies hatch, they eat the nectar and pollen their mother left them. About ten months later they emerge from the nest as fully grown bees.

No one knew about this behavior until around 2009, when two different research teams working in two different countries observed the bee making nests. But the great thing is, the two teams weren’t associated. They only found out later that they’d both observed the same thing on the exact same day. The two teams got together and co-wrote a scientific article about O. avosetta, which is awesome. It seems pretty clear to me that people who like bees are pretty great.

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 159: Sky Animals

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To celebrate my new book, Skyway, this week let’s learn about sky animals! They’re fictitious, but could they really exist? And what animals are really found in the high atmosphere?

You can order a copy of Skyway today on Kindle or other ebook formats! It’s a collection of short stories published by Mannison Press, with the same characters and setting from my novel Skytown (also available)!

Further reading:

“The Horror of the Heights” by Arthur Conan Doyle (and you can even listen to a nice audio version at this link too!)

Charles Fort’s books are online (and in the public domain) if not in an especially readable format

Further Listening:

unlocked Patreon episode The Birds That Never Land

Rüppell’s vulture:

The bar-headed goose:

The common crane:

Bombus impetuosus, an Alpine bumblebee that lives on Mount Everest:

Show transcript:

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

This week we’ve got something a little different. Usually I save the weirder topics for Patreon bonus episodes, and in fact I had originally planned this as a Patreon episode. But I have a new book coming out called Skyway, so in honor of my new book, let’s learn about some sky animals!

Skyway is a collection of short stories about the same characters in my other book Skytown, so if you’ve read Skytown and liked it, you can buy Skyway as of tomorrow, if you’re listening on the day this episode goes live. I’ll put links to both books in the show notes so you can buy a copy if you like. The books have some adult language but are appropriate for teens although they’re not actually young adult books.

Anyway, the reason I say this episode is a little different is because first we’re going to learn about some interesting sky animals that are literary rather than real. Then we’ll learn about some animals that are real, but also interesting—specifically, animals that fly the highest.

Back before airplanes and other flying machines were invented, people literally weren’t sure what was up high in the sky. They thought the sky continued at least to the moon and maybe beyond, with perfectly breathable air and possibly with strange unknown animals floating around up there, too far away to see from the ground.

People weren’t even sure if the sky was safe for land animals. When hot-air balloons big enough to carry weight were invented in the late 18th century, inventors tried an important experiment before letting anyone get in one. In 1783 in France, a sheep, a duck, and a rooster were sent aloft in a balloon to see what effects the trip would have on them. The team behind the flight assumed that the duck would be fine, since ducks can fly quite high, so it was included as a sort of control. They weren’t sure about the rooster, since chickens aren’t very good flyers and never fly very high, and they were most nervous about the sheep, since it was most like a person. The balloon traveled about two miles in ten minutes, or 3 km, and landed safely. All three animals were fine.

After that, people started riding in balloons and it became a huge fad, especially in France. By 1852 balloons were better designed to hold more weight and be easier to control, and that year a woman dressed as the goddess Europa and a bull dressed as Zeus ascended in a balloon over London. But the bull was obviously so frightened by the balloon ride that the people watching the spectacle complained to the police, who charged the man who arranged the balloon ride with animal cruelty. The bull was okay, though, and no one made him get in a balloon again.

After airplanes were invented and became reliable, if not especially safe, the world went nuts about flying all over again. In 1922 Arthur Conan Doyle published a story called “The Horror of the Heights,” about a pilot who flew high into the sky and came across sky animals. You can tell from the story’s title that things did not go well for the main character.

The story is written as though it’s an excerpt from a journal kept by the main character, named Joyce-Armstrong. Early on, Joyce-Armstrong is talking about height records achieved by pilots and that no one has had any trouble that high in the sky. He says,

“The thirty-thousand-foot level has been reached time after time with no discomfort beyond cold and asthma. What does this prove? A visitor might descend upon this planet a thousand times and never see a tiger. Yet tigers exist, and if he chanced to come down into a jungle he might be devoured. There are jungles of the upper air, and there are worse things than tigers which inhabit them.”

After that are some really lovely descriptions of the pilot’s ascent into the sky, trying for both a height record and to see the so-called jungle of the upper air. In the story, he climbs to over 41,000 feet in an open cockpit monoplane without any special equipment. He’s wearing, like, a nice warm hat and wool socks. In actuality, at 40,000 feet, or 12,000 meters, the temperature can be as low as -70 degrees F, or -57 Celsius.

Anyway, Joyce-Armstrong writes in his journal, “Suddenly I was aware of something new. The air in front of me had lost its crystal clearness. It was full of long, ragged wisps of something which I can only compare to very fine cigarette smoke. It hung about in wreaths and coils, turning and twisting slowly in the sunlight. As the monoplane shot through it, I was aware of a faint taste of oil upon my lips, and there was a greasy scum upon the woodwork of the machine. Some infinitely fine organic matter appeared to be suspended in the atmosphere. There was no life there. It was inchoate and diffuse, extending for many square acres and then fringing off into the void. No, it was not life. But might it not be the remains of life? …The thought was in my mind when my eyes looked upwards and I saw the most wonderful vision that ever man has seen. …Conceive a jelly-fish such as sails in our summer seas, bell-shaped and of enormous size—far larger, I should judge, than the dome of St. Paul’s. It was of a light pink colour veined with a delicate green, but the whole huge fabric so tenuous that it was but a fairy outline against the dark blue sky. It pulsated with a delicate and regular rhythm. From it there depended two long, drooping, green tentacles, which swayed slowly backwards and forwards. This gorgeous vision passed gently with noiseless dignity over my head, as light and fragile as a soap-bubble…”

After that, Joyce-Armstrong sees more of the sky jellyfish and some long smoke-like creatures that he calls the serpents of the outer air. And then he’s attacked by a huge purplish creature sort of like a sky octopus with sticky tentacles. He escapes and flies home, writes his journal entry, and says he’s going back to capture one of the smaller sky jellyfish and bring it back to show everyone. And after that, the journal ends except for a terrible addendum scrawled in pencil on the last page. It’s a fun story that you can read for free online, since it’s in the public domain. I’ll put a link in the show notes.

Arthur Conan Doyle is the same author who invented Sherlock Holmes, if the name sounds familiar. But he wasn’t the first one to imagine strange high-altitude sky animals. He was influenced by the writings of a man named Charles Fort. Fort liked to collect the accounts of weird happenings reported in newspaper articles and magazines, and he published his first book in 1919. If you’re a Patreon subscriber you may remember Fort from a bonus episode last October where I talked about a few of his animal-related cases. I’d unlock the episode for anyone to listen to except that I just re-listened to it myself, and at the end I talk about my recent eye surgery in really way too much detail. So I won’t unlock it, but I will say that Fort had a weird writing style that can be hard to follow. He likes to present outlandish theories as though he’s deadly serious, then claim that he’s only joking, then say, “Well, maybe I’m not joking.” His main goal is to make readers think about things that would never have occurred to them.

Fort was especially interested in falls of fish and frogs and other things, which we talked about in episode 140 last October. In his first book he suggested there are places in the sky where items collect, and that occasionally things fall out of those places. He called this the Super-Sargasso Sea, after the Sargasso Sea that’s supposed to be a becalmed area of the ocean where sailing ships get caught because there’s no wind or currents. The Sargasso Sea is a real place in the North Atlantic Ocean that has clear blue water and which is full of a type of seaweed called Sargassum. It’s also full of plastic, unfortunately, since that’s where the North Atlantic garbage patch is.

But Fort described his Super-Sargasso Sea as something between another dimension and an alien world that just brushes up against the earth’s atmosphere. He pointed out that this theory made as much sense as any other explanation for falling frogs and other things, which of course is why he suggested it. He didn’t actually believe it.

This is how Fort describes the super-Sargasso Sea: “I think of a region somewhere above this earth’s surface in which gravitation is inoperative…. I think that things raised from this earth’s surface to that region have been held there until shaken down by storms…. [T]hings raised by this earth’s cyclones: horses and barns and elephants and flies and dodoes, moas, and pterodactyls; leaves from modern trees and leaves of the Carboniferous era…. [F]ishes dried and hard, there a short time; others there long enough to putrefy…. [O]r living fishes, also—ponds of fresh water: oceans of salt water.

“But is it a part of this earth, and does it revolve with and over this earth—

“Or does it flatly overlie this earth…?

“I shall have to accept that, floating in the sky of this earth, there often are fields of ice as extensive as those on the Arctic Ocean—volumes of water in which are many fishes and frogs—tracts of lands covered with caterpillars—

“Aviators of the future. They fly up and up. Then they get out and walk. The fishing’s good: the bait’s right there. … Sometime I shall write a guide book to the Super-Sargasso Sea, for aviators, but just at present there wouldn’t be much call for it.”

That quote is actually cobbled together from pages 90-91, 179, and 182 of my copy of The Complete Books of Charles Fort, because one thing Fort is not good at is a straightforward, clear narrative. Reading his books is like experiencing someone else’s fever dream. But you can definitely see where Conan Doyle got his inspiration for “The Horror of the Heights.”

These days we know a lot more about the sky—or, more technically, about the atmosphere that surrounds the Earth. Researchers have labeled different parts of the atmosphere since the different layers have different properties. The layer closest to the earth, the one that we breathe and live in, is the troposphere. That’s where weather happens, that’s where most clouds are, and that’s where 99% of the water vapor in the entire atmosphere is located. The troposphere extends about 6 miles above the earth, or 10 km, or 33,000 feet. Mount Everest is 29,000 feet high, by the way, or 8,850 meters. Above the troposphere is the stratosphere, which extends to about 31 miles above the earth, or 50 km.

The jet stream, a steady wind that commercial jet planes use to help them cross oceans and continents faster, occurs roughly where the troposphere becomes the stratosphere. Above the jet stream, there’s hardly any turbulence. There are no updrafts, basically no weather, just increasingly thin air. Weather balloons and spy planes ascend into the stratosphere and that’s also where the ozone layer is, but there’s basically not much up that high.

Above the stratosphere is the mesosphere, where the air is too thin for any animal known to breathe, plus the air pressure is only about 1% of the pressure found at sea level. There just aren’t very many air molecules in the mesosphere. This is where meteors typically burn up, and the only vehicles that fly there are rockets. It extends to about 53 miles above the earth, or 85 km, and above that is the thermosphere, the exosphere, and then empty space, although it’s hard to know exactly where the thermosphere and exosphere end and space begins. It’s so far away from the earth’s surface that some satellites orbit within the thermosphere, and that’s where the northern and southern lights are generated as charged particles from the sun bounce against molecules.

But let’s return to the troposphere, our comfortable air-filled home. As far as we know, there aren’t any animals that live exclusively in the air and never land. Even the common swift, which lives almost its entire life in the air, catching insects and sleeping on the wing, has to land to lay eggs and take care of its babies. But what animals fly the highest?

As far as we know, the highest-flying bird is Rüppell’s vulture, an endangered bird that lives in central Africa. It’s been recorded flying as high as 37,000 feet, or 11,300 meters, and we know it was flying at 37,000 feet because, unfortunately, it was sucked into a jet engine and killed. There’s so little oxygen at that height that a human would pass out pretty much instantly, but the vulture’s blood contains a variant type of hemoglobin that is more efficient at carrying oxygen so that it gets more oxygen with every breath. It has a wingspan of 8 ½ feet, or 2.6 meters, and is brown or black with a lighter belly and a white ruff around the neck. Its tongue is spiky to help it pull meat off the bones of the dead animals it eats, but if there’s no meat left on a carcass, it will eat the hide and even bones. The more I learn about vultures, the more I like them.

Any bird that migrates above the Himalayas has to be able to fly incredibly high, since that’s where Mount Everest is and many other mountains that reach nearly into the stratosphere. The bar-headed goose has been recorded flying at 29,000 feet, or 8,800 meters, and in fact, mountaineers climbing Mount Everest have claimed to see and hear the geese flying overhead. The bar-headed goose has the same variant hemoglobin that Rüppell’s vulture has so it absorbs more oxygen with every breath.

The bar-headed goose is pale gray with black and white markings, especially black stripes on its head. It’s not an especially big goose, with a wingspan of about five feet, or 160 cm. It nests in China and Mongolia during the summer, then migrates to India and surrounding areas for the winter, and it generally crosses the Himalayas at night when winds aren’t as high.

The common crane is another high-flying bird, which has been recorded flying at 33,000 feet, or 10,000 meters, above the Himalayas. It’s a large bird with long legs and a wingspan of nearly 8 feet, or 2.4 meters. It’s gray with a red crown on its head and a white streak down its neck, and a tail that’s not so much a tail as just a bunch of floofy feathers stuck to its butt. Supposedly it flies so high to avoid eagles, but it’s a strong bird with a stabby beak that has been observed fighting eagles that attack it. It nests in Russia and Scandinavia but flies to many different wintering sites across Europe, Africa, and Asia.

So those are the three highest-flying birds known, but what about insects? How high can an insect fly?

Most insects can’t fly if the air is too cold, typically if it’s below 50 degrees Fahrenheit, or 10 degrees Celsius. Since the air is that cold just a few thousand feet above ground, that means most insects don’t fly very high, especially small ones. But not all of them.

Because insects are so small and lightweight, they’re often carried by the wind even if they aren’t technically flying, an activity called kiting. In 1961 during a study of insect migrations, an insect trap installed on an airplane caught a single winged termite at 19,000 feet, or 5.8 kilometers above sea level. An insect trap on a weather balloon collected a small spider at 16,000 feet, or 5 km. If you’re wondering how the spider got in the air in the first place, many small spider species travel to new habitats by ballooning, which in this case has nothing to do with a balloon. The spider lifts its abdomen until it feels a breeze, and then it spins a short piece of silk. The breeze lifts the silk and therefore the spider and carries it sometimes long distances.

Some bumblebee species live and fly just fine at high altitudes. The bumblebee Bombus impetuosus lives on Mount Everest, although not at its very top because nothing grows that high. It lives at around 10,600 feet, or 3,250 meters, and studies of how it flies show that it actually beats its wings in a different way from other bumblebees in order to fly at high altitudes where the air is thin.

So maybe there aren’t weird jellyfish-like creatures floating around in the stratosphere, but there are certainly other animals that occasionally reach incredible heights. So I guess the only thing the fictional pilot Joyce-Armstrong really had to worry about was freezing to death.

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 155: Extreme Sexual Dimorphism

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Many animals have differences between males and females, but some species have EXTREME differences!

The elephant seal male and female are very different sizes:

The huia female (bottom) had a beak very different from the male (top):

The eclectus parrot male (left) looks totally different from the female (right):

The triplewart seadevil, an anglerfish. On the drawing, you can see the male labeled in very small letters:

The female argonaut, also called the paper nautilus, makes a delicate see-through shell:

The male argonaut has no shell and is much smaller than the female (photo by Ryo Minemizu):

Lamprologus callipterus males are much larger than females:

The female green spoonworm. Male not pictured because he’s only a few millimeters long:

Show transcript:

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

I still have a lot of listener suggestions to get to, and don’t worry, I’ve got them all on the list. But I have other topics I want to cover first, like this week’s subject of extreme sexual dimorphism!

Sexual dimorphism is when the male of a species looks much different from the female. Not all animals show sexual dimorphism and most that do have relatively small differences. A lot of male birds are more brightly colored than females, for instance. The peacock is probably the most spectacular example, with the males having a brightly colored, iridescent fan of a tail to show off for the hens, which are mostly brown and gray, although they do have iridescent green neck feathers too.

But eclectus parrot males and females don’t even look like the same bird. The male is mostly green while the female is mostly red and purple. In fact, the first scientists to see them thought they were different species.

Males of some species are larger than females, while females of some species are larger than males. In the case of the elephant seal, the males are much larger than females. We talked about the northern elephant seal briefly last week, but only how big the male is. A male southern elephant seal can grow up to 20 feet long, or 6 meters, and can weigh up to 8,800 pounds, or 4,000 kg. The female usually only grows to about half that length and weight. The difference in this case is because males are fiercely territorial and fight each other, so a big male has an advantage over other males and reproduces more often. But the female doesn’t fight, so her smaller size means she doesn’t need to eat as much.

Another major size difference happens in spiders, but in this case the female is far larger than the male in many species. For instance, the body of the female western black widow spider, which lives throughout western North America, is about half an inch in length, or 16 mm, although of course that doesn’t count the legs. But the male is only half this length at most. Not only that, the male is skinny where the female has a large rounded abdomen, and the male is brown with pale markings, while the female is glossy black with a red hourglass marking on her abdomen. Female western widows can be dangerous since their venom is strong enough to kill many animals, although usually their bite is only painful and not deadly to humans and other mammals. But while the male does have venom, he can only inject a tiny amount with a bite so isn’t considered very dangerous in comparison.

The reason many male spiders are so much smaller than females is that the females of some species of spider will eat the male after or even during mating if she’s hungry. The smaller the male is, the less of a meal he would be and the less likely the female will bother to eat him. In the case of the western black widow, the male prefers to mate with females who are in good condition. In other words, he doesn’t want to spend time with a hungry female.

If you remember episode 139, about skunks and other stinky animals, we talked about the woodhoopoe and mentioned the bill differences between males and females. The male woodhoopoe has a longer, more curved bill than the female because males and females eat a slightly different diet of insects so they won’t compete for the same food sources.

But a bird called the huia took beak differences to the extreme. The huia lived in New Zealand, although it officially went extinct in 1907. It was a wattlebird, which gets its name from the brightly colored patch of skin on either side of the face, called wattles. In the case of the huia, the wattles were orange, while the feathers over most of the body were glossy black. It also had a strip of white at the tip of the long tail. The male’s beak was fairly long and pointy, although it also curved down slightly. But the female’s beak was much longer and more slender, curving downward in an arc.

The huia lived in forests in New Zealand, where it ate insects, especially beetle grubs that live in rotting logs. People used to think that a mated pair worked together to get at grubs and other insects. The male would use his shorter, stouter bill to break away pieces of rotting wood until the grub’s tunnel was exposed, and then the female would use her longer, more slender bill to fish the grub out of the tunnel. But actual observations of the huia before it went extinct indicate that it actually didn’t do this. Like the woodhoopoe, males and females preyed on different kinds of insects. The male did break open rotting wood with its beak in a way that’s very different from woodpeckers, though. Instead of hammering at the wood, it would wedge its bill into a crevice of the wood and open its beak, and the muscles and other structures it used to do so were so strong that it could easily break pieces of wood off. This action is known as gaping and other birds do it too, but the huia was probably better at it than any other bird known.

The huia went extinct partly due to habitat loss as European settlers cleared forests to make way for farming, and partly due to overhunting. Museums wanted stuffed huias for display, and the feathers were in demand to decorate hats. And as a result, we don’t have any huias left.

Sometimes the size difference between males and females reaches extreme proportions. We’ve talked about the anglerfish several times in different episodes, and it’s a good example. It’s a deep-sea fish with a bioluminescent lure on its head that it uses to attract prey. Different species grow to different sizes, but let’s just talk about one this time, the triplewart seadevil.

The triplewart seadevil is found throughout much of the world’s oceans, preferably in medium deep water but sometimes in shallow water and sometimes as deep as 13,000 feet, or 4000 meters. The female grows to about a foot long, or 30 cm. It’s black in color, although young fish are brown. Its body is covered with short spines and it has a lure on its head like other anglerfish. The lure is called an illicium, and it’s a highly modified dorsal spine that the fish can move around, including extending and retracting it. At the end of the illicium is a little bulb that contains bioluminescent bacteria. Whatever animals are attracted to the glowing illicium, the fish gulps down with its great big mouth.

But that’s the female triplewart seadevil. The male is tiny, only 30 mm long at the most. The male doesn’t have an illicium; instead, his jaws and teeth are specialized for one thing: to bite onto the female and never let go. When a male finds a female, he chooses a spot on her underside to latch on, and once he does, his mouth and one side of his body actually fuse to the female’s body. Their circulatory and digestive systems fuse too. Before the male finds a female, he has great big eyes, but once he fuses with a female his eyes degenerate because he no longer needs them. He’s fully dependent on the female, and in return she always has a male around to fertilize her eggs. But this attachment is actually pretty rare, because it’s hard for deep-sea fish to find each other.

Another sea creature where the females are much larger and very different from the males is the argonaut, or paper nautilus. The argonaut is an octopus that lives in the open ocean in tropical and subtropical waters. Instead of living on the bottom of the ocean, though, the paper nautilus lives near the surface, and while the female looks superficially similar to a nautilus, it’s only distantly related.

The female argonaut generally grows to about 4 inches long, or 10 cm, although the shell she makes can be up to a foot across, or 30 cm. In contrast, males are barely half an inch long, or 13 mm. The female’s eight arms are long because she uses them to catch prey, with two of her arms being larger than the others. She grabs small animals like sea slugs, crustaceans, and small fish and bites it with her beak, and like other octopuses she can inject venom at that point too. But the male has tiny little short arms except for one, which is slightly larger.

Like other cephalopods, the male uses one of his arms to transfer sperm to the female so she can fertilize her eggs. In most cephalopods that means an actual little packet of sperm that the male places inside the female’s mantle for her to use later. But in the argonaut, the male’s larger modified arm is called a hectocotylus, and it has little grooves that hold sperm. The male inserts the hectocotylus into the female’s mantle, then detaches it and leaves the arm inside her. Then he leaves and regrows the arm, as far as researchers know. We don’t actually know for sure since it’s never been observed, but octopuses do have the ability to regenerate lost arms. The female usually keeps the hectocotylus and sometimes ends up with several.

At that point the female creates a shell by secreting calcite from the tips of her two larger arms. The shell is delicate, papery, and white, and it resembles the shell of the ammonite, which we talked about in episode 86. The female lays her eggs inside the shell, then squeezes inside too, although she can come and go as she likes.

There’s still a lot we don’t know about the argonaut, but we know more than we used to. In the olden days people thought the female used her two larger arms as sails at the surface of the water. Eventually scientists figured out that was wrong, but they were still confused as to why there only seemed to be female argonauts. They didn’t know that the males were so small and so different, and in fact when early researchers found hectocotyluses inside the females, they assumed they were parasitic worms of some kind. Eventually they worked that part out too.

But still, for a very long time researchers thought the argonaut’s shell was just for protecting the eggs, but it turns out that the female uses the shell as a flotation device. She can control how much air the shell contains, which allows her to control how close to the surface she stays. In a 2010 study of argonauts rescued from fishing nets and released into a harbor, if the shell doesn’t contain enough air, the argonaut will jet to the surface and stick the top of its shell above the water. The shell has small openings at this point so air can get in, and once the argonaut decides it’s enough, she seals the holes by covering them with two of her arms. Then she jets downward again until she’s deep enough below the surface that the pressure compresses the air inside the shell and cancels out the weight of the shell. This means the argonaut won’t bob to the surface but she also won’t sink, and instead she can just swim normally by shooting water from her funnel like other octopuses.

A species of cichlid fish from Lake Tanganyika in Africa, Lamprologus callipterus, also differs in size due to a shell, but not like the argonaut. Instead, the male is much larger than the female. The male can be up to five inches long, or nearly 13 cm, while the female is less than two inches long, or 4 ½ cm. The females lay their eggs in shells, but not shells they make. The shells come from snails, so the male needs to be larger so he can pick up and carry a big empty shell. The female, though, still needs to be small enough to fit inside the shell.

A moth called the rusty tussock moth is also sexually dimorphic. Its caterpillar grows around 1 to 1.5 inches long, or 3 to 4 cm, with females being a little larger than male caterpillars but otherwise very similar. But after the caterpillars pupate, they’re much different. The male moth has orangey or reddish-brown wings and a wingspan of about 1.5 inches, or almost 4 cm. The female doesn’t have wings at all. She emerges from her cocoon and perches next to it, and releases pheromones that attract a male. After the female mates, she lays her eggs on her old cocoon and dies, as does the male.

Let’s finish up with an animal you may never have heard of, the green spoonworm. It’s a marine worm that lives throughout much of the Mediterranean and the northeastern Atlantic Ocean. It lives on the sea floor in shallow water, partly buried in gravel and sand. The female grows up to about six inches long, or 15 cm, and sort of looks like a mostly deflated dark green balloon, although it may also look kind of lumpy. It also has a feeding proboscis that it can extend several feet, or about a meter.

As a larva, the green spoonworm floats around in the water, but whether it becomes male or female depends on where it settles. If it lands on the seafloor it transforms into a female and starts secreting a toxin called bonellin. Bonellin is what gives the green spoonworm its dark green color. The bonellin is mostly concentrated in the feeding proboscis and allows the spoonworm to paralyze and kill the tiny animals it eats.

But if the larva happens to land on a female green spoonworm, contact with the bonellin causes it to become a male. And the male is only a few mm long, doesn’t produce bonellin, and can’t even survive on its own. The female sucks the male into her body through the feeding proboscis, but instead of digesting him, he lives inside her and fertilizes her eggs. In return she provides him with all the nutrients he needs. A female may have more than one male living inside her, making sure that her eggs will always be fertilized.

There are lots more animals that show extreme sexual dimorphism, of course, but that at least gives you an idea of how different animals evolve to fit different environmental pressures. Weird as they seem to us, to the animals in question, it’s just normal–and it’s our appearance and how we do things that would seem weird to them. Perspective is everything.

You can find Strange Animals Podcast online at strangeanimalspodcast.blubrry.net. That’s blueberry without any E’s. If you like the podcast and want to help us out, leave a rating and review on Apple Podcasts or whatever platform you listen on. 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 and get twice-monthly bonus episodes.

Thanks for listening!

Episode 147: Snails and the Gooseneck Barnacle

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Thanks to Kim and Richard E. this week for two awesome suggestions! We’re going to learn about land snails and about the gooseneck barnacle!

Some baby snails and a mama snail, or at least an adult snail that is probably ignoring all those babies:

A giant African snail:

Unlocked Patreon episode about giant African snails (and other stuff)

A rare Polynesian tree snail, white-shelled variety:

A grove snail:

Gooseneck barnacles:

A barnacle goose. Not actually related to the gooseneck barnacle:

Show transcript:

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

We’re getting to some more excellent listener suggestions this week, this time about some interesting invertebrates. Thanks to Kim who suggested snails, and to Richard E for suggesting the gooseneck barnacle.

We’ve talked about various snails before, in episodes 27, 57, 81, and 136, but let’s dig in and really learn about them.

Snails are in the class gastropoda, which includes slugs, whether terrestrial, freshwater, or saltwater. Gastropods appear in the fossil record way back in the late Cambrian, almost 500 million years ago. Snails and slugs are so common that no matter where you live, you can probably find one within seconds, if you know where to look.

Snails have shells while slugs don’t, but there’s a third type of gastropod called a semi-slug. It has a shell, but one that’s too small for it to live inside. It’s more of a little armor plate than a snail shell. Slugs also have shells, but they’re vestigial and are actually inside the slug so you can’t see them.

Scientists have long tried to figure out if mollusks developed shells early or if they started out as a wormlike creature that later evolved a shell. A discovery of a 400 million year old mollusk fossil in Wales shows a wormlike body but also a shell—actually seven plate-like shells—which suggests that the shells developed early and that shell-less mollusks later lost them.

The snail has a spiraled shell that it can retract its body into, although not all snails can retract all the way into their shells. Snails that live on land are called terrestrial snails, or just land snails, and those are the ones we’ll talk about today. Land snails have lungs, or rather a single lung, although some land snails have gills instead and live in wet areas, although they’re not technically water snails.

Most land snails eat plant material, which they scrape up using a radula. You may remember from other episodes that the radula is a tongue-like structure studded with tiny chitinous teeth, microscopic ones in this case. Snails are sometimes so numerous that they can cause damage to gardens, so often people buy poison to kill the snails in their yard. But a 2014 study shows that killing snails isn’t very effective. The best way to get rid of snails, or at least minimize the damage they do to gardens, is to pick the snails up and transport them at least 30 yards away, or about 20 meters. Snails have a homing instinct, but distances more than about 20 meters are hard for them to navigate. The snails will probably just make a home where they end up. Also, no throwing them into your neighbor’s garden. That’s cheating.

Most land snails are hermaphrodites, which means the snail fertilizes the eggs of other snails and also produces eggs for other snails to fertilize. Some snails bury their eggs in soil while some hide them in damp leaf litter. The eggs hatch into teeny snails with teeny shells, and as the snail grows, its shell grows too by adding layers at the opening.

Snails need moisture to survive, so a snail secretes mucous that helps it retain moisture. The mucus is also thick enough to protect the snail from sharp objects as it travels around on the flat underside of its body, called a foot. Until recently researchers thought that the mucous also helped the snail move, but it turns out that gastropods move entirely due to muscular motions of the body, which start at the tail and travel in a sort of wave motion to the head. This isn’t the most rapid way to move—a typical snail can only advance about one millimeter per second—but it works for the snail. It can also climb walls and other vertical surfaces since the mucous helps it stick, even if it’s upside-down. The mucus a snail leaves behind in its track is visible until it dries after a few hours, usually called a snail trail or a slime trail.

If a snail’s environment becomes too dry, it will retract itself into its shell and secrete a layer of mucous that hardens, protecting its body from drying out. Later, when the environment is wetter, it softens the mucous and goes about its normal snail activities.

Scientists of all kinds study snails. One recently published study investigated the properties of snail mucous to try to develop an adhesive that can be turned from sticky to non-sticky and back to sticky. Another study from 2011 examined the way snails move to see if that can be adapted to various technologies.

Because snail shells are so common in the fossil record, scientists can measure the oxygen isotopes in shells to learn how dry or wet the environment was during the snail’s life. A recent study of snail shells from the Canary Islands indicates that 50,000 years ago the islands were much wetter than they are now. Also, there were more snails then than now.

The largest living snail known is the giant African snail, which can grow almost a foot long, or 30 cm. It’s native to East Africa but it’s an invasive species in many parts of the world. I actually covered this species of snail in a Patreon episode a few months ago, so I’ll unlock that episode and put a link to it in the show notes if you want to learn more about it. It’s kind of a weird episode and I spend entirely too much time at the end talking about my recent eye surgery, but you’ll learn about the giant African snail and a marine snail called the periwinkle.

New species of snail are discovered all the time, since snails are usually small, often hard to find, and many snails look sort of alike except to the trained eye. In 2012, two species of tiny snails were discovered in a cave in northern Spain. They’re called thorn snails and are less than 2 mm in size. Since they live in caves, like many cave animals they’ve lost pigment and are essentially transparent. More thorn snails new to science were discovered in Panama a few years ago. A snail specimen collected in South America in the 19th century was finally examined a few years ago and described as a new species in 2015. Those are just a few examples; so many snails have been described in the last few decades that it would get boring if I talked about all of them.

Not all snails are brown, of course. Some have lovely shells in different colors, patterns, and shapes. A colorful snail called the Polynesian tree snail, found in Tahiti and a few nearby islands, has been a puzzle to researchers for over a century, since they couldn’t figure out how the snail came to be on the islands. Not only that, but a few of the islands have a variety of the snail with a white shell, which isn’t found on Tahiti. It turns out that the people of the area just liked the white shells, which they used to make jewelry, so they introduced the snails to their islands for a better supply of the shells. The Polynesian tree snail is critically endangered now, but some zoos have started a captive breeding program.

People have eaten snails for thousands of years, and certain species of snail are considered delicacies today. A type of grove snail that lives in Ireland and southern France but not anywhere in between may be evidence that humans brought the snails with them when they first colonized Ireland. Researchers suggest humans arrived in Ireland by boat from southern Europe around 8,000 years ago and brought the snails with them, possibly to farm. They’re actually really pretty snails with a yellow or yellowy-white shell striped with brown.

Another invertebrate humans like to eat is the gooseneck barnacle, also called the goose barnacle. It’s actually a crustacean, and I’m glad I checked because I was honestly certain that it was another mollusk. I think I had it mixed up with certain types of clams with long siphons. But the gooseneck barnacle is a crustacean like last week’s roly poly, but unlike the roly poly, it actually tastes really good—if you can get it.

The gooseneck barnacle attaches itself to rocks and other hard objects in intertidal areas of the Atlantic and Pacific, and it prefers rough water. It can be dangerous to gather. Richard E., who suggested the topic, specifically mentioned the variety known as percebes, which is a delicacy popular around the Iberian peninsula, especially in Portugal and Spain. He mentions that people have died trying to get them, and that his own grandparents have a saying about them, “If you want to get, you have to get your backside wet.”

The gooseneck barnacle attaches itself to an object by its stalk, called a peduncle, which is strong and tough enough to withstand rough waves. At the end of the stalk is the capitulum, which contains the body and is protected with five plates. It extends its legs, which are called cirri and resemble feathers, from an opening in the capitulum, and uses them to filter tiny organisms out of the water that it eats.

Like the land snail and many other invertebrates, the gooseneck barnacle is a hermaphrodite. It mates with the nearest other gooseneck barnacle, and since it literally cements itself to its rock and can’t move afterwards, it’s a good thing that barnacles live in clusters or there wouldn’t be any new ones, since the gooseneck barnacle can’t fertilize its own eggs. The barnacle keeps its fertilized eggs inside its body until they hatch into tiny larvae, which it releases into the water. The larvae live in the sea as plankton for a few months, moulting six times before they metamorphose into cyprid larvae. You may remember that term from the horrifying zombie animals episode last month, but these cyprid larvae are just looking for a nice rock to cement themselves to.

The gooseneck barnacle gets its name from its long stalk, which resembles a goose’s neck, and the protective plates on the capitulum do kinda-sorta look like a goose’s beak from the right angle. Now, back in the olden days people didn’t know that birds migrate. People knew that some birds lived in their area in the winter or summer, but they didn’t know what happened to the birds the rest of the year. Some people believed some birds hibernated, others actually believed they flew to the moon during the winter. In the case of a goose called the barnacle goose, which mostly breeds on remote Arctic islands and then spends the rest of the year in various parts of Europe, in the early medieval days people actually thought it didn’t actually lay eggs or have babies. They thought it and the gooseneck barnacle were the SAME ANIMAL, but that the gooseneck barnacle was a young barnacle goose that was still developing. Therefore, people rationalized, they weren’t actually geese but some sort of fish so could be eaten during Christian fast days when meat wasn’t allowed. This lasted until 1215 when the pope said no, actually, wherever they come from, those things are birds and you can’t eat them on fast days.

The gooseneck barnacle is still causing consternation these days. In 2016, some pieces of driftwood washed up on a few New Zealand beaches, covered with gooseneck barnacles. No one knew what in the heck those things were. A species of gooseneck barnacle is native to the area, but they aren’t usually seen on sandy beaches where people like to swim. A picture of the barnacles caused a lot of speculation as to what they were until scientists and naturalists identified them. Fortunately, though, no one suggested they were baby geese.

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. You can also support the show and get two bonus episodes a month by signing up as a patron at Patreon.com/strangeanimalspodcast.

Thanks for listening!

Episode 146: Three strange animals

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The next few weeks will be all listener suggestions! This week, Dylan and Genevieve of What Are You? Podcast request a strange fish, Kim suggests a strange invertebrate, and Callum suggests a strange bird. Thanks for the great suggestions!

An archerfish, pew pew pew:

A regular roly poly and a spiky yellow woodlouse. Can you spot which is which??

A nightjar. Turn out light pls, is too bright:

A white-winged nightjar showing off his wings:

Show transcript:

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

I’m really, really behind in getting to suggestions, as you will probably know if you have sent in a suggestion and you think I’ve forgotten all about it. So before the end of the year, which is coming up frighteningly fast, I’m going to try to get to a lot of the older suggestions. So this week we’re going to learn about a fish, an invertebrate, and a bird.

We’ll start with the archerfish, suggested by Dylan and Genevieve, who are part of the What Are You? Podcast. If you don’t already listen to What Are You?, I really recommend it. It’s a new animal podcast that’s especially for younger kids. If you like Cool Facts About Animals, you’ll like What Are You? Anyway, Dylan and Genevieve both really like the archerfish, so let’s find out why it’s such a weird and interesting fish.

The archerfish isn’t one fish, it’s a family of fish who all catch insects in an unusual way. Most archerfish species are small, maybe 7 inches at the most, or 18 cm, but the largescale archerfish can sometimes grow up to 16 inches long, or 40 cm. All archerfish live in Asia or Australia, especially southeast Asia. They like rivers and streams, sometimes ponds, and a few species live in mangrove swamps and the mouths of rivers where the water is brackish. That means it’s saltier than ordinary fresh water but not as salty as the ocean.

The reason the archerfish is so weird is the way it catches insects. Think about its name for a minute. Archer-fish. Hmm. An archer is someone who uses a bow and arrow, but obviously the archerfish doesn’t have arms and hands so it can’t shoot tiny arrows at insects. But it can shoot water at insects, and that’s exactly what it does.

The archerfish has really good eyesight, and it learns to compensate for the way light refracts when it passes from air to water. When it sees an insect or other small animal, maybe a spider sitting on a branch above its stream, it rises to the surface but only far enough so that its mouth is above water. Then it forms its tongue and mouth to make a sort of channel for the water to pass through. Then it contracts its gill covers, which shoots a stream of water out of its mouth. But because it shapes it mouth in a really specific way, the stream of water turns into a blob as it flies through the air, like a tiny water bullet. The water hits the spider, which falls from its branch and into the stream, where the archerfish slurps it up.

But the archerfish has to learn how to aim. Young archerfish aren’t very good at it, and they have to practice to shoot accurately and far. They can even learn by watching other archerfish shooting water, which is rare among all animals but practically unheard-of in fish.

Sometimes the archerfish will shoot underwater, sending out a jet of water instead of a bullet. It does this mostly to expose small animals hidden in the silt at the bottom of a pond or stream. And sometimes, of course, if the insect is close enough to the surface of the water, the archerfish will just jump up and grab it.

The archerfish shoots water with a force that’s actually six times stronger than its muscles would allow, and it does this by taking advantage of natural water dynamics. This means it uses a lot less energy to shoot water than if it was only using its muscles, and it gets a better result. It can shoot water up to ten feet away, or three meters, to bring down an insect or other small animal, although of course it prefers closer targets.

Archerfish do well in aquariums, so they’ve been studied by scientists to find out how smart they are. It turns out, they’re pretty darn clever. The archerfish takes into account the size of its target to adjust how strong a blob of water it needs to shoot. It also recognizes individual humans by their facial features. So it’s probably a good thing that they don’t have little arms and hands.

Next, Kim sent me some great suggestions way back in August, and I feel terrible that I’ve taken so long to get to any of them. We’ll look at one of those today, an invertebrate officially called a terrestrial isopod, although you may know it by one of a lot of different names. My preferred name for it is roly poly, but it’s also called a sowbug, a wood louse, a pillbug, a doodlebug, and many others.

You have probably seen roly polies, because they’re really common. The most well-known family are the various species that can actually roll up into a ball when threatened, Armadillidiidae, and someone with a sense of humor came up with that name. They’re native to Europe, but they’ve been introduced all over the world. They’re gray or brown-gray in color, armored on the back with overlapping segments, with seven pairs of little legs underneath and a pair of little antennae.

Roly polies eat decaying plant material and sometimes living plants, especially if the plant is wet. In a pinch, they will also eat dead insects and other decaying matter, but mostly they just want that yummy rotting leaf. As a result, they’re valuable decomposers in the food web. They also need moisture to breathe, so they’re often found in soil, under rocks and leaf litter, and in moss.

But Armadillidiidae isn’t the only family of roly polies. Most roly polies actually can’t roll up at all, so I should start using one of their other names, woodlouse. Technically, woodlice are crustaceans. You know, related to crabs and lobsters. But they are infinitely cuter than other crustaceans. And if you’re curious about whether they taste like lobster, apparently they taste awful, like urine. I don’t even want to think about how anyone knows what a woodlouse tastes like, or how anyone knows what urine tastes like. Yuck. Anyway, they’re descended from marine isopods that ventured out on land over 300 million years ago, but a few species have returned to the water and are aquatic.

All woodlice have segmented, flattened bodies with seven pairs of legs. When a woodlouse molts its exoskeleton, it does it in two stages. It molts the back half first, then the front half a few days later. This means that it’s not as unprotected as other arthropods that shed the whole exoskeleton at once.

There’s another arthropod called a pill millipede that looks a lot like a woodlouse, including being able to roll into a ball. But it’s actually not very closely related to the woodlouse. Pill millipedes have 18 pairs of legs and a smoother appearance.

Almost all woodlice are gray or brown, although a few may have small yellow spots. But one is actually yellow and looks very different from other woodlice. It’s called the spiky yellow woodlouse, which is a perfect description. It’s critically endangered, because it only lives in one part of the world, a volcanic tropical island in the South Atlantic, Saint Helena. It lives in trees, but it’s so threatened by habitat loss and introduced rats and other non-native species of woodlice that a captive breeding program is underway to save it. There may be as few as 100 individuals left in the wild, but fortunately it’s a lot easier to keep in captivity than, say, 100 rhinoceroses.

Let’s finish with a bird. Callum suggested caprimulgiformes, which includes nightjars, potoos, oilbirds, and whippoorwills. We’ve talked about a few of them before in previous episodes, including the oilbird in episode 121 and the Nechisar nightjar in episode 70. I know we’ve talked about the tawny frogmouth somewhere, but I can’t remember which episode. Maybe it was a Patreon episode. But we’ve never looked at most caprimulgiformes, so let’s do that now, because they are weird birds. We’ll focus on the nightjars, which are also sometimes called goatsuckers, not to be confused with the chupacabra, which also means goatsucker. In the olden days people used to think nightjars snuck into barns at night and suckled milk from dairy goats. They don’t, though. Birds can’t digest milk.

Nightjars and their close relatives are nocturnal, although some species are mostly crepuscular, which means they’re most active at dawn and dusk. Like the owl, the nightjar’s feathers are very soft so that it can fly silently. It eats insects, especially moths.

There are three subfamilies of nightjars: the typical nightjars, the eared nightjars, and the nighthawks, with lots of species in each group. They live throughout most of the world and they all look similar. We’ll take one typical nightjar as an example, the European nightjar. It lives throughout most of Europe and part of Asia, although it migrates to Africa for the winter. It’s brown and gray mottled with lighter and darker speckles, which makes it really hard to see when it’s sitting on a branch or on the ground in dead leaves. Its head appears flattened and it has a short, broad bill. Its feet are small. It has large eyes and sees well even in darkness. It grows to about 11 inches long, or 28 cm, with a wingspan of about two feet, or 60 cm.

The female nightjar lays her eggs directly on the ground instead of building a nest. Usually she’ll pick a spot where long grass or other vegetation hangs over to form a little hidden alcove. Since the nightjar is so well camouflaged, it can incubate its eggs on the ground in plain sight and probably won’t be seen. If a predator does approach the nest, the parents will pretend to be injured, so that the predator follows the supposedly injured bird hoping for an easy meal. Once the nightjar has drawn the predator far enough away from the nest, it flies away. Some nightjars can even pretend to be injured while flying.

Some nightjars have beautiful, haunting songs while some are nearly silent. The male chuck will’s widow, which lives in the southeastern United States and much of Mexico, sings at night and also claps his wings to show off for females. His song sounds like this.

[chuck will’s widow song]

Because nightjars are so well camouflaged and mostly nocturnal, they’re hard for birdwatchers and scientists to spot. As a result, there are undoubtedly nightjar species still unknown to science. This is the case with the Nechisar nightjar, which we talked about in episode 70. It’s only known from a single wing found on an otherwise squashed dead bird that was hit by a car. And until 1997, the white-winged nightjar from South America was only known from two museum specimens.

Since the first white-winged nightjar nest was discovered in 1997, researchers have learned a lot about it. It’s only been found in a few places in Brazil, Bolivia, and Paraguay, and it likes open lowlands and savannas. The male has white markings on his wings, and during breeding season he finds a termite mound to stand on, spreads his wings to show them off, and then flies up. As he does, his wings make a distinctive sound. Since most nightjars fly silently like owls, the beating of the male’s wings is intended to attract a female. This is what it sounds like:

[white-winged nightjar wings beating]

Like other nightjars, the white-winged nightjar female lays her eggs directly on the ground. Some researchers think she times the eggs to hatch around the full moon so the parent birds have more light to forage for insects. In years where there’s lots of food, the female may lay eggs in a second nest near the first one and incubate them while the male feeds the babies of the first nest.

Many nightjar species are endangered due to habitat loss, but it’s also killed by cars more often than other birds because of its habit of sitting in the road. That does not strike me as being very smart. Maybe it needs to talk to the archerfish for some advice.

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!

This is what the little nightjar sounds like. It lives in South America:

[little nightjar calls]

Episode 142: Gigantic and Otherwise Octopuses

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Happy birthday to me! For my birthday, we’re all going to learn about octopuses, including a mysterious gigantic octopus (maybe)! Thanks to Wyatt for his question about skeletons and movement that is a SURPRISE SPOOKY SKELETON SEGMENT of the episode, or maybe not that much of a surprise if you read this first.

Further reading:

How octopus arms make decisions

Octopus shows unique hunting, social and sexual behavior

Kraken Rises: New Fossil Evidence Revives Sea Monster Debate

The larger Pacific striped octopus is not especially large, but it is interesting and pretty:

The giant Pacific octopus is the largest species known. It even eats sharks, like this one:

Show transcript:

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

Today happens to be my birthday, and not just any birthday. It’s a significant birthday that ends with a zero. That’s right, I’m TWENTY! Or maybe a little bit older than that. So for my birthday celebration, and one week closer to Halloween, let’s learn about the octopus. The episode was going to be about possible giant octopuses, but as I researched, octopuses in general turned out to be so interesting and weird that that’s what the episode is about. But we will talk about some mystery gigantic octopuses at the very end.

The first thing to know about the octopus is what the correct plural is. Sometimes people say octopi but that’s actually technically incorrect, although it’s not like you’ll be arrested if you say octopi. The correct plural of octopus is octopuses, although octopodes is also correct. No one says octopodes because that sounds weird.

But who cares about that, because we’re talking about awesome creepy weird cephalopods! The octopus lives in the ocean but it can come out of the water and walk around on land if it wants to, although it usually only does so for a matter of minutes. The octopus breathes through gills but it can also absorb a certain amount of oxygen through its skin, as long as its skin stays moist. Generally people don’t see octopuses come out of the water because most octopuses are nocturnal.

Most octopuses spend their time on the ocean floor, crawling around looking for food. When it’s threatened or frightened, though, it swims by sucking water into its body cavity and shooting it back out through a tube called a siphon, which allows it to jet propel itself quickly through the water headfirst with its arms trailing, so that it looks like a squid. But most of the time the octopus doesn’t swim like this, because when it does, the heart that pumps blood through most of the body stops. The octopus has three hearts, but two of them are only auxiliary hearts that move blood to the gills to make sure the blood stays oxygenated.

Octopus blood is blue because it’s copper-based instead of iron-based like the blood of mammals and other vertebrates. This allows it to absorb more oxygen than iron-based blood can. Since many octopuses live in cold water that doesn’t contain very much oxygen, they need all the help they can get.

The octopus also uses its siphon to release ink into the water when it’s threatened. Of course it’s not ink, but it is black and resembles ink. Also, people have used octopus ink to write with so, you know, I guess maybe it is sort of ink. Anyway, when the octopus releases ink, it can choose to mix it with mucus. Without the mucus, the ink makes a cloud of dark water that hides the octopus while it jets away, and it may also interfere with the predator’s sense of smell. With the mucus, the ink forms a blob that looks solid and in fact looks a lot like a dark-colored octopus. This is called a pseudomorph or false body, and the octopus uses it to confuse predators into thinking it’s still right there, when in fact the octopus is jetting away while the predator attacks the false body. Researchers have found that young sea turtles who attack the false body thinking it’s the real octopus later ignore real octopuses instead of trying to eat them.

In addition to their ninja-like ability to disappear behind a smoke screen, or ink screen, the octopus can also change its color and even its texture to blend in with its background. Its skin contains cells with different-colored pigments, and tiny muscles can change both the color and the texture of the cells. Think of it like being able to shiver to give yourself goosebumps whenever you want, but at the same time you can change the color and shape of the goosebumps. An octopus species that lives in shallow water and is active during the day generally can camouflage itself better than a species that lives in deeper water and is nocturnal, and small species are typically better at camouflage than large ones. Some species mimic rocks or algae with six arms and use the other two arms to creep along the ocean floor, inching away from a potential predator without it noticing.

But the octopus doesn’t just use its ability to change colors to hide from predators. It also communicates with other octopuses by changing colors. And some species have a special threat display of bright colors that warns predators away. This is especially true of the blue-ringed octopus that lives in the Pacific and Indian Oceans, which will display bright blue spots if it feels threatened. Since the blue-ringed octopus has the strongest venom of any octopus, if you see this particular threat display, swim away quickly. I don’t know why I’m assuming my listeners include sharks and whales. Actually, the place you’re most likely to encounter a blue-ringed octopus is in a shallow tide pool on the beach, so watch where you step.

You probably already know what an octopus looks like, but I haven’t actually mentioned it yet. The octopus has a bulbous body with two large eyes, eight arms lined on the bottom with suckers, and in the middle of the arms, a mouth with a beak. The beak looks sort of like a parrot’s beak and is made of chitin, a tough material that’s similar to keratin. Inside the mouth, the octopus has a radula, a tongue-like structure studded with tiny tooth-like bumps.

Until about ten years ago, researchers thought that only the blue-ringed octopus was venomous. The blue-ringed octopus is tiny but super venomous. Its venom can kill humans, although that’s extremely rare. But now we’ve learned that all octopuses appear to have venomous saliva, most of it relatively weak, but enough to kill mollusks and other small animals. The octopus eats anything it can catch, for the most part, including crabs, shrimp, small fish, mollusks, and so forth. Its suckers can attach so firmly to a bivalve’s shells that it can pull the shells apart. If it can’t manage this, though, it will cover the shells with its toxic saliva. The toxin dissolves tiny holes in the shell and kills the mollusk, allowing the octopus to open the shells easily and eat the animal inside. It can also inject the toxins into crabs to paralyze them, then uses its beak to bite the shells open without the crab being able to fight back.

The octopus can regrow an arm if it’s bitten off or otherwise lost. Some species will even drop an arm like some lizards can drop their tails in order to distract a predator. In the case of the lizard, its tail thrashes around after it’s detached, while in the case of an octopus arm, the arm continues to crawl away and tries to escape from being hurt. This is creepy to the extreme, especially when you realize the arm acts this way because it contains a sort of brain of its own.

An octopus’s brain doesn’t fully control its arms. In fact, the arms contain about twice the number of neurons that the brain contains, which means they can act autonomously in a lot of ways. Basically, each octopus arm processes information the same way that a brain does, without involving the actual brain. The arms have an excellent sense of touch, naturally, and the suckers have chemical receptors that act as a sense of taste as well. When an arm touches something, the arm decides whether it’s food, or if it’s dangerous, or if it’s in the way, or so forth. Then it decides what it should do about it. The arms use the peripheral nervous system, again not the brain, to make decisions that require arms to work together. The result is that the arms can all work at different tasks, together or separately, while the central brain is processing other information, primarily from its eyes. But also as a result, the octopus doesn’t have a good sense of where its body is in space at all times. You don’t have to see your arms to figure out where they are in relation to your body, but the octopus does.

This is all very different from the way our brains work. Researchers study the octopus to determine how its brain works with the arms to help the octopus navigate its environment. Some researchers point out that the octopus’s intelligence is so different from the intelligence of other animals we’ve studied that it’s as close as we can come to studying intelligent life from another planet.

The main reason why the octopus has such a different nervous system is that it’s an invertebrate. Humans and other mammals, birds, reptiles, and fish are all vertebrates, meaning they have a backbone of some kind. The backbone contains a spinal cord that is the main pathway for the nervous system, connecting the brain with the rest of the body. The brain processes everything that the body does. But invertebrates and vertebrates started evolving separately over half a billion years ago, and while most invertebrates don’t demonstrate a lot of what we would consider intelligence, the octopus does. Instead of a central spinal cord of nerves, the octopus, like other invertebrates, has concentrations of neurons throughout its body, called ganglia. The ganglia form a sort of neural net. This actually means the octopus can process information much more quickly than a human or other vertebrate can.

And the octopus is intelligent, probably as intelligent as parrots, crows, and primates. An octopus can learn to recognize individual humans and solve complex puzzles, can learn from watching another octopus solve a problem, and many species use tools in the wild. Some species of octopus spend the day in dens that they make out of rocks, including a rock door that they close after they go inside. The veined octopus will collect pieces of coconut shells, stack them up, and carry them around. If it’s threatened, or if it just wants to take a nap or rest, it uses the coconut shells as a hiding place.

Octopuses in captivity can cause a lot of trouble because they’re so intelligent. They will dismantle their tanks out of curiosity or just escape. An octopus in an aquarium in Bermuda escaped repeatedly in order to eat the fish and other animals displayed in nearby tanks. A common New Zealand octopus named Inky, kept at the National Aquarium, was famous for causing mischief, and one day in 2016 he managed to move the lid to his enclosure just enough to squeeze out. Then he walked around until he found a small pipe. He squeezed into the pipe, and fortunately for him it was a pipe that led directly outside and into the ocean.

The reason that octopuses can squeeze through such tiny openings is that they have NO BONES. There is not a single bone in the octopus’s body. The only hard part of the body is its beak. As long as the octopus can get its beak through an opening, the rest of the body can squish through too.

And that brings us to a surprise spooky SKELETON SECTION, thanks to a suggestion by Wyatt!

[spooky scary skeletons song!]

Wyatt wants to know how bones work and move, which is a good question and will help us learn about octopuses too. Bones have many purposes, including making blood cells and protecting the brain—that would be the skull part of the skeleton, of course—but mainly bones help your body move. Muscles are attached to bones, and when you contract a muscle, it moves the bone and therefore the rest of that part of your body. Without muscles, your bones couldn’t move; but without bones, your muscles wouldn’t do much. Also, you’d look sort of like a blob because bones provide structure for your body.

But if you need bones to move, how does an octopus move? An octopus has no bones! Do I even know what I’m talking about?

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

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

There are exceptions to the “bones and muscles work together” rule, of course. Your tongue is a muscle. So is an elephant’s trunk, or at least it’s made up of lots and lots of muscles that aren’t attached to bones. Tongues and elephant trunks and worms and things like that all use muscular hydrostatic functioning to move.

The octopus has a lifespan that seems abbreviated compared to other intelligent animals. It typically only lives a year or two and dies soon after it has babies. After the female lays her eggs, she stops eating and instead just takes care of the eggs, which she attaches to a rock or other hard surface. It usually takes several months for the eggs to hatch, and all that time the female protects them and makes sure they have plenty of well-oxygenated water circulating around them. She dies about the time the babies hatch. As for the male, he doesn’t take care of the eggs but after he mates with a female he starts showing signs of old age and usually dies within a few weeks. That’s if the female doesn’t just decide to eat him after mating. Most male octopuses stay as far away as they can from a female while mating, and uses one of his arms to transfer a packet of sperm into her mantle, which she uses to fertilize her eggs.

At least one octopus species has been observed to brood its eggs for four and a half years, guarding them from predators and keeping them clean. Researchers studying life in an area of Monterey Bay called Monterey Canyon, off the coast of western North America, regularly survey animals in the area. In May of 2007 they saw a female octopus on a rocky ledge about 4,600 feet, or 1,400 meters, below the surface. She had distinctive scars so the researchers could identify her, and she didn’t leave her eggs once during the next four and a half years. She also didn’t appear to eat or even be interested in the small crabs and other delicious octopus food within easy reach of her. As the years went by she became thinner and paler. She and her eggs were still there in September of 2011 but when the researchers returned in October, she was gone and her eggs had hatched.

Babies are teensy when they’re first hatched, typically only a few millimeters long. The babies drift with the currents and eat tiny animals like zooplankton as they grow. One exception is the same deep-sea octopus species that spends so long protecting its eggs, Graneledone boreopacifica. Because they develop in the egg for so long, babies of this species are much larger than most baby octopuses and can even hunt for small prey immediately.

Another exception to the usual octopus habit of only reproducing once before dying is the larger Pacific striped octopus, which lives in the eastern Pacific Ocean in warm, shallow water. Not only is it gregarious, instead of mostly solitary like other octopus species, it can reproduce repeatedly without dying. Mated pairs sometimes live and hunt together and even share food. Despite the word “larger” in its name, the larger Pacific striped octopus only grows to about three inches across, or 7 cm. It is striped, though. It’s quite attractive, in fact. And its many differences from other octopus species show just how little we know about octopuses.

So how big can an octopus grow? We don’t actually know. The species that grows the largest is called the giant Pacific octopus, and the biggest one ever measured had an armspan of about 30 feet, or 9 meters.

But there are always rumors and sightings of octopuses of colossal sizes, often referred to as the gigantic octopus or the colossal octopus. In 2002 a fishing trawler brought up the incomplete carcass of a dead octopus near New Zealand, and estimates of its armspan when it was alive are around 32 feet, or 10 meters. In 1928 a man named Robert Todd Aiken reported seeing six octopuses off the coast of Oahu, Hawaii with armspans of nearly 40 feet, or 12.5 meters. In 1950, also off the coast of Oahu, a diver named Madison Rigdon reported seeing an octopus with each arm alone measuring almost 30 feet, or over 9 meters.

But because octopuses are soft-bodied animals that are eaten by so many predators, and because the biggest ones typically live in deeper water, we just don’t know that much about how big they can get. When we do find a big dead octopus, its size is difficult to estimate since cephalopods actually shrink quite quickly after they die.

We only have a few remains of ancient octopuses, mostly body impressions and fossilized beaks. In 2009, paleontologists working in Lebanon reported finding five specimens of fossilized octopus that date to 95 million years ago. The specimens are remarkably well preserved, too, which allows researchers to determine that the octopuses belong to three different species that appear to be unchanged from their modern counterparts. In 2014 the impressions of cephalopod beaks dated to around 80 million years ago were found in Hokkaido, Japan. The impressions were well preserved and paleontologists have determined that all but one belonged to an extinct species related to the vampire squid, that we talked about in episode 11. They estimate its body to have been about two feet across, or 60 cm, without the arms. The other beak impression was from a different species, one related to modern squid.

If you listened to episode 86 about ammonoids and nautiloids, which are related to octopuses, you may remember that some extinct species grew enormous, probably over 19 feet long, or 6 meters. Since those species have shells, we have a lot more fossilized remains.

But we have almost no remains of ancient octopuses, so we have no way of knowing how big some species once grew. The colossal squid was only determined to be a real animal a matter of years ago (and we talked about it and giant squid in episode 74). I wouldn’t be one bit surprised if the colossal octopus was one day found to be a real animal too.

Let’s finish with an ancient cephalopod mystery. The octopus is a messy eater, so sometimes researchers can identify an octopus’s territory by the way it leaves shells lying around. Some species of octopus arrange shells and other items in heaped-up patterns around its den. In 2011 a pair of paleontologists named Mark McMenamin and Dianna Schulte McMenamin examined an unusual pattern of ichthyosaur remains in Nevada and suggested that they might have been arranged by an octopus after eating them. But since the nine ichthyosaurs are 45 feet long, or 14 meters, the octopus would have had to be equally enormous. Dr. McMenamin and other Dr. McMenamin think the octopus might have killed the ichthyosaurs by either breaking their necks or drowning them, or both. In 2013 the team investigating the site found what may be part of a fossilized cephalopod beak, further backing up the theory. Then again, that species of ichthyosaur, Shonisaurus, ate squid and other cephalopods, so it’s possible the beak was actually inside an ichthyosaur stomach when it died and that a giant octopus or other cephalopod had nothing to do with the deaths. Still, it’s fun to think about, and it might be true!

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 141: Zombie Animals

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We’re inching closer to Halloween and it’s getting spookier out there! This week let’s learn about some animals that get zombified for various reasons. This is an icky episode, so you might not want to snack while you’re listening. Thanks to Sylvan for the suggestion about the loxo and mud crabs!

Further reading:

Zombie Crabs!

Ladybird made into ‘zombie’ bodyguard by parasitic wasp

A mud crab held by a dangerous wizard:

A paralyzed ladybug sitting on a parasitic wasp cocoon:

A cat and a rodent:

Show transcript:

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

It’s another week closer to Halloween, so watch out for ghosts and goblins and zombie animals! Zombie animals?! Yes, that’s this week’s topic! Thanks to Sylvan for suggesting the loxo parasite, which we’ll talk about first. Brace yourself, everyone, because it’s about to get icky!

Before we learn about loxo, let’s learn about the mud crab, for reasons that will shortly become clear. Mud crab is the term for a whole lot of small crabs that live in shallow water, mostly in the Atlantic or eastern Pacific Oceans but sometimes in lakes and other fresh water near the ocean, depending on the species. Most are less than an inch long, or under about 30 mm. The largest is called the black-fingered mud crab, which grows to as much as an inch and a half long, or 4 cm. Most mud crabs are scavengers, eating anything they come across, but the black-fingered mud crab will hunt hermit crabs, grabbing their little legs and yanking them right out of their shells. It also uses its strong claws to crack the shells of oysters.

Loxothylacus panopaei is actually a type of barnacle. You know, the little arthropods that fasten themselves to ships and whales and things. But loxo, as it’s called, doesn’t look a bit like those barnacles except in its larval stages. After it hatches, it passes through two larval stages; during the first stage, it molts four times in only two days as it grows rapidly.

Then, during the cyprid larval stage, the microscopic loxo searches for a place to live. The male remains free-swimming but the female cyprid larva is looking for a mud crab. She enters the crab’s body through its gills and waits for it to molt its exoskeleton, during which time she metamorphoses into what’s called a kentrogon, basically a larva with a pointy end. As soon as the crab molts its exoskeleton, the female loxo uses her pointy end, called a stylet, to stab a hole in the crab’s unprotected body. Then she injects parasitic material that actually seems to be the important part of herself, which enters the crab’s blood—called hemolymph in arthropods like crabs. Like most invertebrates, crabs don’t have blood vessels. The hemolymph circulates throughout the inside of the body, coming into direct contact with tissues and organs. This means that once the loxo has infiltrated the hemolymph, she has access to all parts of the crab’s body.

At this stage, the loxo matures into something that isn’t anything like a barnacle, but is an awful lot like something from a horror movie. She grows throughout the crab, forming rootlets that merge with the crab’s body and changes them. Basically, the female loxo becomes part of her crab host. Eventually she controls its nervous system and molds it to her own needs. She even molds the body to her own needs, since if she’s parasitized a male crab she has to widen its body cavity so it can hold her eggs.

The crab stops being able to reproduce and doesn’t want to. It only wants to care for the eggs that the female loxo produces. She extrudes an egg sac so that it hangs beneath the crab’s abdomen, where a male loxo can fertilize it when he swims by. The crab then treats the egg sac as if it contains its own eggs, protecting them and making sure they get plenty of oxygenated water. This is true even for male crabs, which ordinarily don’t take part in protecting their own eggs. The loxo eggs hatch in about a week, and as soon as they do, the female loxo inhabiting the crab starts the process over again. While a mud crab in the wild can live for a few years, once it’s taken over by the loxo parasite it only lives around 45 days.

Most mud crab populations are reasonably resistant to the parasite, but where the loxo has been introduced to areas where it didn’t live before, it can decimate the local mud crab population. This happened in Chesapeake Bay in the 1960s in North America. The local oysters had been so over-fished that they were nearly completely gone, also nearly destroying the local oyster industry. They imported oysters from the Gulf of Mexico to replenish local stocks, but no one realized they were bringing the loxo with those oysters. These days, up to 90% of the Chesapeake Bay mud crabs are infected with the loxo parasite, while only up to 5% of the Gulf of Mexico mud crabs are infected. Researchers at the Chesapeake Bay Parasite Project are working to figure out more about how the loxo infiltrates its host and changes it genetically, and are monitoring infection rates in the wild.

If you think that’s gross, it’s not going to get any better the rest of this episode.

Next let’s learn about another zombie animal, this one a spider. A number of spiders are parasitized by a tiny wasp called Zatypota percontatoria. It lives throughout much of the northern hemisphere and prefers forested areas with plenty of web-building spiders in the family Theridiidae, also known as cobweb spiders.

Cobweb spiders are really common with around 3,000 species that live throughout the world, including the black widow, which by the way is not nearly as dangerous as people think. Some cobweb spiders are kleptoparasites, which means they steal food and other resources from another animal, in this case larger spiders. A kleptoparasite cobweb spider actually lives in the web of a larger spider, and when a small bug gets caught in the web, it steals it. Sometimes the cobweb spider will kill and eat the spider that built the web in the first place too.

But most cobweb spiders are ordinary spiders, and most are quite small, usually only a few millimeters long. Many are marked with pretty patterns in brown, white, black, and other colors. Different species build different kinds of webs, but they all eat small insects.

As for the wasp, it’s about the same size as the spider it’s trying to parasitize, and sometimes smaller. It has long wings, long antennae, and a long abdomen that in the female ends in a sharp ovipositor. The female finds a spider, usually a young spider that’s less able to defend itself, and stabs it in the abdomen with her ovipositor. Then she lays a single egg inside the spider and flies away.

The egg doesn’t bother the spider, although once the egg hatches into a larva it starts to feed on the spider’s hemolymph. Remember, that’s the equivalent of blood in the invertebrate world. At the same time, it’s releasing hormones into the spider that change its habits. Basically the wasp larva controls the spider so that it acts to the benefit of the larva, not itself.

All this takes about a month. When the larva is ready to pupate and metamorphose into an adult wasp, it secretes a final hormone that influences the spider’s behavior. This one causes the spider to spin a strong, cocoon-like web. When the web is finished, the larva bursts out of the spider’s body, killing it, and eats the spider. Then it enters the cocoon and develops into an adult wasp.

Because spiders are good at defending themselves, only about 1% of spiders end up parasitized. I’m sure the spiders think that’s 1% too many. There are other parasitic wasp species in other places, but they all act about the same as Zatypota.

Another wasp, Dinocampus coccinellae, parasitizes ladybugs. Like Zatypota, the female wasp lays one egg in the ladybug’s body. When it hatches, the larva eats the ladybug’s insides while the ladybug continues to go about its ordinary activities. But after several weeks, the larva is ready to pupate. It paralyzes the ladybug, bursts out of its body, and spins a cocoon that the ladybug sits on.

But the ladybug isn’t dead. It protects the cocoon from other insects by twitching and making grasping motions with its legs.

After about a week, the adult wasp emerges from its cocoon and flies away. The ladybug usually dies, but not always. About a quarter of infected ladybugs recover and are fine. Researchers aren’t sure how the wasp larva causes the paralysis. It may release a virus that infects the ladybug or it may have something to do with venom released by the larva.

This wouldn’t be a proper zombie episode if I didn’t talk about that disgusting parasitic fungus that affects certain carpenter ants in the rainforests in Brazil and Thailand. It completely squicks me out so I’m going to explain it very, very quickly.

Fungal spores float through the air and land on an ant, where they stick. They release enzymes that eventually break down the ant’s exoskeleton, allowing the fungus to spread inside the ant’s body. Finally it’s able to control the ant and makes it crawl up the stem of a plant and bite into a leaf vein. The ant is unable to move at this point and eventually dies. The fungus sprouts from inside the ant and grows into stalks, especially from the ant’s head. About a week later it releases spores that go on to infect other ants. Ugh. So glad I’m not an ant.

Ants can sense when one of the colony has contracted the fungus, and will carry the infected ant far away from the colony so it’s less likely to infect others. The ants also groom each other to remove any spores that may have attached. The fungus can completely destroy ant colonies, but it has a parasite of its own, another fungus that stops the first fungus from releasing spores. A related parasitic fungus also infects certain caterpillars.

Look, I’m totally over talking about fungus, so let’s move on.

So is there any chance that a parasite will turn you into a zombie? There’s not, but a behavior-changing parasite does sometimes infect humans. It’s called Toxoplasma gondii, and while its effects on human behavior has been studied extensively, the effects are so minor as to be nearly nonexistent in most cases.

Toxoplasmosis is a disease caused by a single-celled parasite, and it’s one that not only infects humans, it’s really common. I probably have it but I’m not going to think too hard about that. For most people, it never bothers them and never causes any symptoms, or only mild short-term symptoms like a lowgrade cold that takes a few weeks to clear up. But it can be more serious in people with a suppressed or weak immune system, and can cause problems for the baby if its mother gets infected while she’s pregnant.

There are estimates that up to half the people in the world are infected with toxoplasmosis but never know. The reason it’s so common is that the parasite targets cats, and can be spread in cat feces. And, you know, if you scoop out the cat’s litter box you might be exposed. That’s why pregnant women shouldn’t clean up after a cat. Infection can also result from eating undercooked meat from an infected animal, eating unwashed fruit or vegetables, drinking unpasteurized milk, and drinking untreated water.

Any mammal or bird can contract the parasite, but it can only reproduce in a cat’s digestive system. It doesn’t hurt the cat, it just wants to get inside the cat so it can reproduce. And the best way to get inside a cat is to be part of a rodent that a cat eats.

When a rat or other rodent is infected with Toxoplasma gondii, its behavior changes. Suddenly, it starts to like cats. You can probably see where this is going. Not only does it stop avoiding cats, it actually seeks them out. The cat, naturally, can’t believe its luck, kills and eats the rodent, and may become infected.

If you have a pet cat, the best way to reduce the risk of contracting toxoplasmosis is to scoop the litter box daily, then wash your hands. It takes about a day for the parasite to become active after being shed in cat poop, so if you scoop the litter box right away the risk is lower. Researchers are working on vaccines, and they’ve actually already developed a vaccine that’s now used in sheep. If you keep your cat inside, where it’s safer anyway, it’s much less likely to be exposed to the parasite in the first place.

So, take ordinary precautions but don’t worry too much about toxoplasmosis. Unless, of course, you are a rodent.

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!