Category Archives: animals

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!

Episode 140: Rains of Fish and Frogs (and other things)

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We’re starting off October (you know, MONSTER MONTH) with accounts of animals that fall from the sky like rain, mostly fish and frogs! Is this a real thing that actually happens, and if so, what causes it?

Further reading:

Raining Frogs

Recent observations of “mystery star jelly” in Scotland appear to confirm one origin as spawn jelly from frogs or toads

Not a real photo of an octopus falling in a storm:

This photo is probably real, two shrimp/prawns on a windshield in the same storm as above (in 2018):

A photo of people picking up fish in the street but I have no idea where it was taken:

An arctic lamprey found in someone’s yard:

Some of the stuff called star jelly, star rot, or star snot:

A walking catfish:

Show transcript:

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

It’s finally October, and that means monsters and other spooky stuff! I have lots of fun episodes planned this month, but first, an important announcement!

A few weeks ago I got a message from someone on Podbean, and I feel terrible because I can’t reply or even see the whole message or who it’s from! Podbean does not like me. I get an email with the first couple of lines of the message but when I click through and log in to Podbean to see the whole message and respond, Podbean goes, “Message? What message? You don’t have any messages.” So please, person who messaged me with a suggestion I can’t see, I’d love it if you email me at strangeanimalspodcast@gmail.com! And if anyone else has ever messaged me somewhere but never received a reply, email is the best way to get hold of me. I always reply, so if you don’t get an answer it means I never saw your message and you should totally send it again. Thanks!

So, back to the October fun! Let’s start off the month right with a strange phenomenon that’s been reported for untold centuries all over the world. Do fish and frogs and other animals actually sometimes fall from the sky like rain?

It seems pretty certain that while this is a rare event, and not all reports are of animals that actually fell from the sky, it does sometimes happen. In fact, lots of weird stuff falls from the sky from time to time. For instance, after a heavy rain over Punta Gorda, Florida at the end of August 1969, the streets were full of golf balls, dozens of them if not hundreds. But there wasn’t a golf course near the town.

Sometimes colored rain falls instead of ordinary clear water. This happens because raindrops form around tiny specks of dust or pollen in the air. When the dust is colored, the rain will be too. Red rains come from dust blown into the atmosphere from the Sahara while yellow rain results from dust from the Gobi Desert. Volcanic eruptions, soot, and other pollutants in the air can cause black rain. And a red rain that fell in Kerala, India in July 2001 was analyzed and the color found to be due to fungal spores. Snow is occasionally colored too, just like rain.

But sometimes frogs, fish, or other small animals do apparently fall from the sky, with or without rain. Here’s a typical report of a rain of frogs. It comes from the book The Unexplained by zoologist Karl Shuker, whose honesty and scholarship I trust. Not only that, it’s something that happened to his own grandmother, Gertrude Timmins. In 1902, Gertrude was only eight years old. She and her mother were walking across a field in the West Midlands in England when it started to rain. They opened their umbrellas, but a moment later Gertrude noticed that amid the regular pattering of rain on an umbrella there were some heavier thumps. Then she noticed that the thumps were caused by small frogs falling onto her umbrella and bouncing off onto the ground. Gertrude was frightened at first, naturally, because that’s just a weird thing to happen to anyone. But her mother told her not to be scared, it was just a rain of frogs.

Remember, Gertrude and her mother were walking across a field. There weren’t any trees or buildings around that the frogs might have fallen from. So where did they come from?

The main hypothesis is that the animals are picked up by a water spout or small tornado and carried on the wind until they’re dropped elsewhere, miles away. When I was a kid I thought this was a dumb suggestion. If a dissipating water spout dropped everything it had picked up out of a pond, why do people just report one kind of frog falling from the sky or one kind of fish? Where’s the algae, water plants, turtles, mud, and other stuff presumably also picked up and carried out of a pond?

The answer may be pretty simple. When the wind velocity is high, the tornado or water spout can carry heavy objects, but as the wind slows and loses energy, it starts to drop the heaviest items. But the wind is still moving, so as it moves across the land and slowly loses more and more energy, it drops the heaviest items first, then the next heaviest items, then the next heaviest, and so on.

It might not even be a tornado or water spout. A powerful updraft, which is often associated with storms, can lift light items like sticks, leaves, and pool toys and drop them miles away. Small frogs often weigh no more than a penny does and during breeding season can be incredibly common in a small area, hopping everywhere. It’s reasonable to assume that sometimes these little frogs get lifted from one area by a strong updraft and dropped elsewhere, astonishing anyone who happens to see it. If you doubt the strength of an updraft, keep in mind that storms can also generate downdrafts and they can be so powerful they destroy or uproot trees.

No one has witnessed frogs or other animals get sucked up into the air and dropped elsewhere, so we don’t know if it actually happens this way. But the animals are obviously getting into the air somehow.

Frogs aren’t the only animals witnessed to fall from the sky. Fish are actually probably the most common animals that fall with rain. It doesn’t even have to be raining.

On October 23, 1947 fish fell over Marksville, Louisiana in the United States. A biologist was having breakfast with his wife in a local restaurant when the server said that fish were falling from the sky. Naturally he went to look. He identified the fish as several different freshwater species common in the area, including two species of sunfish, a type of bass, and a few others, all ranging from 2 to 9 inches long, or 5 to 23 cm. It was a foggy but calm morning with no reports of tornados or strong winds in the area.

It’s possible that a small waterspout formed over one of the many nearby lakes, sucked up whatever fish happened to be in the wrong place at the wrong time, and deposited them a few miles away. Waterspouts form the same way tornados do except that it happens over water. The inside of a waterspout, like the inside of a tornado, is a low-pressure tunnel inside a high-pressure cone of air. It acts like a vacuum cleaner, sucking up water as it moves, and anything that’s in the water near the surface gets sucked up too.

There are two types of waterspouts. Tornadic waterspouts are tornados that happen to touch down over water instead of land. They can be dangerous and are usually reported in the local news and weather if they’re spotted. But fair-weather waterspouts aren’t associated with storms, although they do form ahead of developing storm systems. They’re typically smaller, much less dangerous, and much less likely to be reported to the news. So it’s possible that the 1947 fish fall was the result of a fair-weather waterspout.

This phenomenon isn’t something that used to happen in the olden days and doesn’t happen now. In June of 2009, there were tadpole rains in parts of Japan on two different days in slightly different areas. One man saw over a hundred dead tadpoles on car windshields in one parking lot after a rain shower.

On June 13, 2018, shrimp and possibly other sea creatures fell on the coastal city of Qingdao [zhing-daugh], China during a storm. The media reported it as a “seafood rain” since people posted photos of octopus, squid, starfish, mollusks, and shrimp that they claimed had fallen during the storm. Some of the photos are hoaxes, especially the ones of octopuses flying through the air, but at least some of them are real. Some people speculate that the source of the animals may have actually been a market stall, but since the city is on the coast of the Yellow Sea and the storm’s winds were measured at 77 mph, or 125 km per hour, it’s just as likely that the animals were lifted into the air from shallow water as from a market stall.

Sometimes we can figure out what the cause is of falling animals. In 2015 the Alaska Department of Fish and Game received four separate calls from people who’d found arctic lampreys on their property, including the parking lot of a store and someone’s front yard. If you remember from waaaaay back in episode 3, where we talked about the sea lamprey, lampreys are jawless fish with suckerlike mouths. They latch onto a fish and use their rasping teeth to parasitize it. The arctic lamprey grows to about a foot long on average, or 30 cm, but occasionally one will grow twice that long. It lives in cold freshwater lakes and rivers in the arctic, although it’s found as far south as Japan. An investigation revealed that all four lampreys found on land had cut marks and bruises in a specific pattern, which indicated that they’d been picked up in the beak of a seagull and then dropped, probably by accident when the lamprey wriggled too much. In 2015 there were an unusually high number of arctic lampreys in the Chera River, near where the four lampreys were reported on land.

A substance often referred to as star jelly or star rot has been seen in various parts of the world for centuries, usually connected in folklore with comets and shooting stars. In late 2008 through February 2009 the BBC’s Scotland Outdoors website collected photos and accounts of star jelly people had encountered in Scotland and other places. People reported finding lumps of the usually clear or white, jelly-like substance in their gardens, on walkways, on fence posts, stumps lawns, on the side of the road, in pastures, on rocks, and so on. One person found a lump of it on his tractor, another on a 3rd floor balcony.

Even hundreds of years ago some people suspected star jelly had something to do with frogs. At least some of it looks like the jelly-like matrix that surrounds the eggs of many frog and toad species. This is backed up by the presence of small black eggs in some star jelly that look like frog eggs. But it’s clearly not exactly frog spawn and is often found in places where a frog would never lay its eggs, even if it could for instance get up onto a third floor apartment balcony.

Many samples of star jelly have been examined by scientists and found to be the spawn jelly of frogs and toads, which is produced by the female to surround the eggs and keep them damp. As the female lays her eggs, each one is coated with a layer of spawn jelly, which absorbs water in the environment and increases in volume. Sometimes when a predator tears a frog or toad into pieces to eat it, the reproductive tract is torn open and its contents falls to the ground. When the spawn jelly is exposed to the air, it starts to absorb moisture from whatever it’s touching. This will make it swell up and become much more noticeable to people, especially if it’s rained and the spawn jelly has absorbed a lot of water.

Often an animal will eat a frog or toad, then later regurgitate the less digestible parts. This includes spawn jelly and some parts of the reproductive tract, specifically the oviducts since they contain the spawn jelly. Sometimes eggs are mixed in too. Star jelly has been examined and tested frequently, although most DNA testing has been inconclusive since samples are contaminated with bacteria. But a 2015 DNA test determined that the star jelly was from a frog. The test also found traces of magpie DNA, so we can probably guess what ate the frog.

Some star jelly doesn’t have anything to do with amphibians, though. Instead, some are slime molds or a type of freshwater algae-like bacteria known as nostoc. Neither slime molds nor nostoc fall from the sky but they can appear suddenly, so people may assume that’s what happened. Many birds that eat frogs and toads will eat them in midair, and may also regurgitate the indigestible portions while flying, so at least some star jelly does fall from the sky.

Sometimes people assume an animal has fallen from the sky when it actually hasn’t. For instance, the walking catfish will wriggle across dry land to find water when its pond dries up. It can grow up to 1 ½ feet long, or half a meter, and is usually grayish-brown with little white spots. Its skin is covered with mucus that helps keep it from drying out when it’s out of water. It’s native to parts of Southeast Asia, but it’s been introduced to other places, including southern Florida. In places where it’s not native, people may not be familiar with its ability to breathe air and move around out of the water, so when they see the walking catfish on land they may assume it fell from the sky.

The walking catfish is an invasive species in many areas. It’s an omnivore and can tolerate all kinds of habitats, including stagnant water where other fish can’t survive, since it can breathe air. Fish farmers in areas where the walking catfish lives have to put fences up around their ponds to keep walking catfish out. And if you see one, don’t pick it up. Its fins have spines that help stiffen them so it can use them to move more effectively on land, but that make them sharp.

We obviously don’t know everything about animals that fall from the sky, so let’s finish with a real mystery. It’s called the Kentucky Meat Shower and it happened on March 3, 1876 in a tiny community called Olympia Springs, Kentucky.

Olympia Springs is east of Lexington, Kentucky, in the southeastern United States. These days it’s in the Daniel Boone National Forest and just outside of the Olympia State Forest, so there’s not much in the area except wilderness. This was probably also the case in 1876 except that in 1876 there probably wasn’t a Dairy Queen restaurant a ten minute drive away. Wikipedia says it happened in a community named Rankin in the same county, but most other sources say Olympia Springs. Either way, it was an isolated, remote area at the time.

On this particular day, a woman only identified as Mrs. Crouch was in the yard, making soap. It was a perfectly clear day, not a cloud in the sky, when suddenly it started raining meat. She said it fell like big snowflakes all around her, but presumably not as pretty as snow, and lasted for several minutes. It was fresh meat, looked like beef or other red meat, and the pieces were irregularly shaped and gristly. Some were as big as 4 inches across, or 10 cm, but most about half that size. The meat landed all around, including on fences, in an area estimated to be about 100 yards across and 50 yards wide, or 91 by 46 meters.

Mrs. Crouch and her husband were understandably shaken by this event, and records don’t report whether the soap got finished that day but I suspect not. The next morning, the meat was still lying around, but it had dried out overnight and was starting to spoil. A couple of men stopped by and actually tasted it—ugh, I hope they at least cooked it first—and said they thought it might be venison or mutton. That’s meat from deer and sheep, respectively.

Samples of the meat were sent to various experts who examined it. Keep in mind that this was 1876 so they couldn’t do much more than look at it under an old-timey microscope. Two samples were identified as lung tissue, two as cartilage, and three as muscle.

As soon as the story hit the newspapers, people were quick to offer solutions that didn’t actually fit the reported facts. One person suggested that it was just nostoc that hadn’t actually fallen from the sky, it had been on the ground all along but that rain had made it swell up, which is something nostoc does. Never mind that nostoc is a slimy bacteria that looks nothing like meat—remember, it’s sometimes identified as star jelly—and that it wasn’t raining at the time and that Mrs. Crouch actually saw it fall and that pieces of it were found draped over fences. Plus, nostoc doesn’t taste like venison or mutton. Plus, samples were identified as actual meat.

The main suggestion is that some vultures were flying overhead and had disgorged some meat they had eaten, which had been caught by the wind and fell across a wide area. But while even nowadays people claim that is what must have happened, it has one big flaw. Vultures don’t disgorge meat while they’re flying. They disgorge it as a way to deter predators approaching their nest, and they may disgorge if a predator approaches while they’re feeding so they can get into the air quickly, but not while flying. Not only that, but any meat disgorged by a vulture would smell and taste horrible, since it would have already been rotting before the vulture ate it, and it would then be coated with caustic vulture digestive juices.

So what might have caused the Kentucky Meat Shower? If it wasn’t a newspaper hoax, which were really common in the late 19th century, it might have been the result of some poor animal that was swept up by a tornado, torn apart, and the smallest pieces dropped over the Crouch’s farm after the winds had dissipated. Presumably the heavier pieces, like bones, fell earlier and probably landed in the forest where no one saw them fall. I looked for a weather report for Kentucky for that day, but couldn’t find one. Eastern Kentucky is not too far north from where I live in East Tennessee, so I can verify that March can be a very warm month with unsettled weather. It wouldn’t be at all unusual to have a storm strong enough to generate a small but powerful tornado in March, although this usually happens at night after a hot day.

I don’t know if I believe the Kentucky Meat Shower really happened or if it was a hoax. But either way, we can stop blaming vultures.

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 139: Skunks and Other Stinkers

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This week we’re commemorating my HOUSE getting SKUNKED by a SKUNK and it was STINKY

The skunk, stinky but adorkable, especially when it’s eating yellow jackets:

The stink badger looks like a shaved skunk with a bobbed tail:

The zorilla wants to be your stinky friend:

A woodhoopoe, most magnificent:

A Eurasian hoopoe, looking snazzy:

Show transcript:

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

This week we’re going to learn about some animals that are infamous for their stinkiness. This wasn’t the topic I had planned on for this week, but last week my house got skunked. That is, a skunk sprayed an animal very close to my house, which means I woke up at 4:45am gagging from the smell of point-blank skunk odor. And this was with the windows closed and the air conditioning going. It was so bad I thought I would throw up, so I yanked on my clothes, grabbed my purse, and fled the house at 5:30am. I went to work early—don’t worry, I got coffee on the way—and spent the whole day smelling skunk faintly where the smell clung to my hair and, oddly, my phone case. Also I spent the whole day complaining to my coworkers.

Fortunately, when I got home the smell had dissipated somewhat, so I opened all the windows and doors and by the next morning it was mostly gone. But it got me wondering why skunk spray smells so, so bad and how many other stinky animals are out there.

The skunk is native to North and South America, although there are two species of related animals that live in some of the islands of the Malay Archipelago, called stink badgers. No seriously, that’s really what they’re called. Skunks and stink badgers are related to actual badgers and to weasels, but not closely.

The stink badger is black or dark brown with a white stripe that runs from its head down the back of its neck and along its spine, and finishes at its little short tuft of a tail. The skunk is black or dark brown with one or two white stripes or white spots, depending on the species, which continues down its long fluffy tail. In all cases, though, these stinky animals are vividly patterned with dark fur and bright white markings as a warning to other animals. Do not get too close or there’s a world of stink coming your way. Also, I can verify from my own experience that the white markings of a skunk make it much easier to see in the darkness and therefore avoid. Since the skunk is crepuscular, meaning it’s most active around dusk and dawn, that’s important. The stink badger is more nocturnal than the skunk.

Both the skunk and the stink badger have relatively short legs with sharp claws. Both are relatively small, about the size of a cat. Both are also good diggers and spend the daytime asleep in their burrows. In winter the skunk doesn’t hibernate but it does stay in its burrow more, spending most of its time asleep. This is the best way to deal with winter cold, if you ask me.

Female skunks share a den in the winter but males are usually solitary. This means the females retain a higher amount of body fat when the weather warms up, since they didn’t need to burn that fat to keep themselves warm. Researchers think this helps the females stay in better condition for a spring pregnancy. Meanwhile, males are skinnier at the beginning of the winter but by staying alone they’re less likely to contract disease or parasites.

Mating season for skunks is in spring and babies are born in early summer. They mostly stay in the burrow for about two months, then start accompanying their mother when she goes out foraging. The mother is really protective of her babies and will spray any animal that approaches.

Although the skunk can hear and smell well, it has poor vision. That’s why so many are killed by cars. The skunk’s biggest predator is the great horned owl, because owls don’t have much of a sense of smell and don’t care about being sprayed.

The skunk and the stink badger are both omnivorous and will dig up grubs and earthworms, will sometimes eat carrion, and also eat frogs, crustaceans, and other small animals, leaves and other plant parts, especially berries and nuts, and insects. The skunk especially likes bees. It has thick fur that helps protect it from stings, and will eat all the bees it can catch.

The skunk also eats other stinging insects, including the dreaded yellow jacket. That’s a type of wasp that’s common where I live, with incredibly painful stings. A few years ago I noticed a yellow jacket nest in the ground behind my garage, and that night when the yellow jackets were asleep I carefully trimmed the long grass around the nest opening to see how extensive it was. Then I made a mental note to get some yellow jacket poison the following day. When I went back out to deal with the nest the next night, it was gone. A skunk had discovered it, probably because I’d exposed it by trimming back the grass, and had dug the whole nest up to eat the yellow jackets. There wasn’t a single one left. Ever since I have been lowkey fond of skunks, although I do wish they wouldn’t spray so close to my house.

So what is skunk spray and why is it so stinky? The skunk has two anal glands that contain an oily liquid made up of sulfurous chemical compounds. If a skunk feels threatened, it will raise its tail and fluff it out as a warning. It may also hiss, stomp its feet, and pretend to charge its potential attacker. The skunk doesn’t actually want to spray if it can avoid it, though. Its anal glands only hold enough of the oil to spray a few times, and when the skunk runs out it can’t spray again for almost two weeks. But if its warnings don’t work, it will use muscles to contract the glands and spray the oily liquid more than ten feet, or 3 meters.

If you’ve only ever smelled skunk spray in the distance, you may not think it’s so bad. But the smell is horrific up close, strong enough to induce vomiting, and it can cause irritation to the skin or even temporary blindness if it gets in the eyes. And the skunk is really accurate when spraying, aiming at the face. Not only that, because it’s an oil, the spray clings to skin, hair, or fur, and it won’t just wash off. It can literally take weeks to wear off normally. If your clothes get sprayed, or your dog’s collar, the smell will never come out and you will have to throw the clothes away.

Domestic dogs get sprayed by skunks a lot. Some dogs just never learn. I once had a cat who was sprayed by a skunk too. You may have heard that you can remove the smell by washing your pet in tomato juice, but this actually doesn’t work. I asked a veterinarian how to clean up my cat, and this is what she told me. This worked great, by the way.

Mix hydrogen peroxide about half and half with warm water and add about a spoonful of dishwashing liquid. Rub the mixture into the fur thoroughly, making sure to work it in well right down to the skin. If you can tell where the spray is, concentrate on that part. Do your best not to get the mixture into your pet’s eyes, and make sure to use good warm water. Part of the reason animals hate getting bathed is because they get cold really easily once their fur is wet, so using really warm water helps. Then rinse your pet thoroughly, making sure to get all the soap out so they won’t get itchy. You may need to mix up another batch of the hydrogen peroxide, water, and soap and give the stinkiest areas another wash. After you’ve rinsed your pet thoroughly, wrap them up in a towel and gently squeeze as much of the water out of the fur as you can. Then make sure you have a dry towel to put in your pet’s bed or basket or wherever it wants to hide after its horrible bath.

In July of 2019 a research team published a report about a type of fungus that makes a chemical called pericosine A that neutralizes noxious chemicals. The researchers tested pericosine on skunk spray and discovered that it neutralized the smell harmlessly. So it’s probably just a matter of time before pericosine is marketed to veterinarians to help pet owners. Let’s hope so.

Even skunks don’t like to be sprayed, incidentally. Males fight each other during mating season and will sometimes spray each other. A skunk reacts like any other animal when it gets sprayed.

The zorilla is another stinky animal related to the skunk, although it lives in parts of Africa. It’s brown with white markings and is sometimes called the striped polecat or African skunk. It’s about the same size as a skunk or stink badger and looks and acts very similar, although it’s a carnivore and much more social than the skunk. It’s also related to the honey badger, which we talked about in episode 62. If you remember, the honey badger is also black with a broad white or silvery stripe down its back, and it can invert its anal sacs and discharge a stinky oil, although it doesn’t spray like a skunk.

It’s not really surprising that all these animals are related, since most members of the weasel family, known as mustelids, have anal scent glands that produce a strong odor. Most species just use the glands to mark their territory, though.

But are there animals who spray like skunks but aren’t related to the skunk? Many animals have anal glands for marking territory, and if threatened some animals will empty the anal glands as a form as defense. The king ratsnake will sometimes do this, as will the lesser anteater, the opossum, and others.

But there’s another animal that actually sprays a smelly substance for defense, and it’s not one you’d expect. It’s a bird called the hoopoe, along with its relative the woodhoopoe.

The woodhoopoe lives in woods, savannah, and rainforests of Africa. It looks something like a cuckoo, with a very long tail marked with white spots. It’s mostly a metallic black in color, although some species have markings in other colors. Males have longer, more curved bills than females because they eat larger insects that live in bark and rotten wood while females eat smaller insects that live mostly on leaves. In this way, mated pairs don’t compete with each other for food.

The hoopoe lives across Eurasia and parts of Africa, and while it’s related to the woodhoopoe, it looks very different. It has a long crest that it can raise and lower like a crown, and it’s a pretty tan or brown color with black and white markings. Both males and females have long, slightly curved bills that they use to catch insects and other small animals.

Female hoopoes and woodhoopoes are picky about nesting spots. The female likes to nest in dead trees in rotting wood, or sometimes in a gap in a rock wall. The female incubates her eggs alone. But animals find dead trees and crumbling walls easy to climb, so to protect her nest the female can spray a foul-smelling liquid from the gland that most birds just use to secrete preening oil. This is the case for the female hoopoe and woodhoopoe too most of the time, but after she lays her eggs the gland becomes weaponized. Not only that, when the babies hatch, they develop the same gland. The female rubs the stinky oil on her babies and on the nest to deter predators, and researchers think it may also deter parasites. If an animal approaches the nest anyway, the female can spray the oil at it. And if the female is off catching food for her babies, the babies will hiss, peck, and squirt liquid poop at the predator. At that point, most predators probably just decide to go hunt something else. After they clean up.

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 138: City Animals

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This week we’re going to learn about some animals that have made their homes in cities alongside humans. Thanks to Corianne who suggested this amazing topic!

Further reading:

The BBC’s Urban Fox FAQ

Toronto vs. Raccoons

The urban fox has a favorite coffee shop and knows where to find parking downtown:

The urban raccoon’s apartment is really small but it’s in a great location:

The urban (rock) pigeon can walk to work in good weather:

Show transcript:

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

This week we’re going to look at animals that live in cities. This is a great suggestion by Corianne, who especially suggested the pigeon. But pigeons aren’t the only animals that live in cities alongside people. In fact, in 2018 a large-scale camera trap study of animals in Washington DC and Raleigh, NC concluded that just as many mammal species live in cities as live in the countryside. That’s only mammals, though. There aren’t as many species of other animals in cities.

Different animals hang out in cities in different parts of the world. In parts of Africa and Asia, local monkeys have moved into cities and cause mischief by stealing food from markets and tourists. Gulls are also thieves of food, sometimes getting so bold as to snatch a sandwich from a person’s hands while they’re eating it, even in cities nowhere near the ocean. City parks attract squirrels and deer, decorative fountains and ponds attract geese and ducks as well as alligators, peregrine falcons move in to feast on pigeons, rats, and other small animals, and some cities have to deal with the occasional bear or leopard, wild boars, even penguins. But today we’re going to focus on three really common city dwellers, both because they’re interesting and because there are so many misconceptions out there about them.

We’ll start with urban foxes. We talked about foxes in episode 106, but while urban foxes are plain old red foxes and not a separate species or subspecies, they’ve adapted to city life easily since they’re omnivores and agile animals that can climb obstacles like fences.

Many cities throughout the world have urban foxes, but they’re especially common in the UK. They eat out of trash cans for some of their diet, but they also hunt rats and other small animals that live in cities too, along with earthworms, insects, and even plants. They especially like fruit and acorns. When a fox finds some food, it will often run off with it and bury it somewhere, then come back later to eat it.

Because an urban fox doesn’t have to worry about predators as much as ordinary countryside foxes do, it can grow larger on average than its country cousins. But it’s also in more danger of being hit by cars or infected with diseases common to dogs and other canids, like mange and distemper.

Urban foxes have a bad reputation for biting, attacking pets, and in general being a nuisance. But the fox is just being a fox and doing the best it can. In many parts of the world, the red fox’s natural habitat is fragmented more every year as cities grow larger and farmland and woodland is turned into houses. Besides, foxes have been reported in cities for a long time—over a century in London, England, where foxes are relatively common. They especially like areas with parks, or where people have gardens or lawns.

The biggest problem with urban foxes is people who treat them like they’re dogs. They’re wild animals, so while it’s okay to leave food out for them, don’t try to touch one or get too close to it. Foxes who get too used to people can become aggressive. Foxes usually don’t bother animals as large as cats, either, and they avoid dogs, but don’t leave small pets like guinea pigs or rabbits outside, especially at night, because that is just asking for trouble.

The urban fox doesn’t always live only in the city, though. One fox, nicknamed Fleet, was tagged by researchers in 2014 and tracked to see where he spent his time. To their surprise, Fleet lived up to his name and traveled from the city of Hove into the countryside across England. In 21 days he traveled 195 miles, or 314 km, and probably went farther but his GPS tracker stopped working so we don’t know how far.

This is what a fox sounds like:

[fox sound]

In the UK, foxes are frequent city animals, but in North America it’s much more common for raccoons to fill the same ecological niche. The raccoon is native to North and Central America although it’s been introduced in parts of Europe as a fur animal and briefly to Japan as a pet. The raccoon makes a really bad pet, by the way. It’s not domesticated and will tear your house up.

The raccoon is mostly gray or gray-brown with some lighter areas of fur, black rings on its bushy tail, and black markings over its eyes. It grows a little over two feet long, or around 70 cm, not counting its tail. Its legs are relatively short and it scurries instead of really running, although it can swim well. The raccoon is a great climber and can even climb down trees headfirst by turning its hind feet so that they point backwards, which gives it a better grip. It has sharp claws too, and dexterous hands although they don’t have opposable thumbs. The raccoon’s front paws have as many sensory receptors as human hands, which means it can learn a lot by just touching something. Like, for instance, how to unlock a trash bin.

The raccoon is well-known for getting into trash no matter what kind of bin it’s in. This is because raccoons are remarkably intelligent. By now you probably know that intelligence and social complexity are linked, but raccoons have a much different society than other intelligent animals. Groups of related females generally occupy the same territory and come together to eat and rest, while males usually live in small groups that are mostly separate from females.

Like the fox, the raccoon is an omnivore. It eats insects and worms, fruit and nuts as well as other plant material, bird and reptile eggs, frogs, fish, crustaceans, and other small animals. Raccoons in captivity are known to wash their food by dipping it in water, but this behavior hasn’t actually been documented in wild raccoons. Some researchers think the raccoons aren’t actually trying to clean the food, but are mimicking the motion of catching food in water, while others suggest the raccoons are stimulating the nerve endings in their hands with water to learn more about the food they’re touching.

Raccoons prefer open forests near water, since they like to catch fish and frogs. But they will eat pretty much anything, which means they raid trash bins. For years, the city of Toronto in Canada had trouble with raccoons getting into people’s trash bins. The bins were designed to be picked up and emptied by city trucks, but the raccoons had learned to break the locks. In 2015 the city redesigned the bins to be raccoon resistant, and in 2016 after extensive testing the new bins were distributed to residents. Before long the raccoons had figured out how to open them.

Researchers think that the daily puzzles urban raccoons solve to find food actually make them smarter. Since they’re pretty smart to start with, that’s kind of scary.

Like urban foxes, urban raccoons can get too used to humans. They’re rarely dangerous to people or pets, but they can cause a real mess if they get into your house and will bite if they feel threatened.

This is what a raccoon sounds like:

[raccoon sound]

We’ll finish with the ubiquitous city bird, the pigeon. It’s properly called the rock pigeon or rock dove and is native to parts of Eurasia and Africa. But these days it’s spread throughout much of the world, especially in cities.

Most people are familiar with the pigeon. It’s usually gray or brownish-gray with a white patch on its rump and two broad stripes of black on its wings. Both males and females have iridescent feathers on the neck that shine green and purple in sunlight, but the iridescence in males is much more pronounced. Pigeons with other markings are either feral domesticated pigeons or have feral domesticated pigeons in their ancestry. The domesticated pigeon was actually developed from the rock pigeon and it’s probable that most city pigeons are actually mostly feral domesticated pigeons.

The pigeon is a fairly large bird, up to 15 inches long, or 37 cm, with a wingspan over two feet, or 72 cm. It mostly eats seeds and other plant material, but will also eat small insects. City pigeons will eat bread and other foods too, but they would be happier with whole grains. Like many other birds, the pigeon stores food in its crop after swallowing it, which allows it to eat more food than it would otherwise be able to hold. The crop is a chamber at the bottom of the esophagus.

Not only do pigeons have a crop, which not all birds have, pigeon parents produce a food called crop milk or pigeon milk that they feed to babies. It’s not milk at all, of course, but the nutrient-rich lining of the crop that it sheds and regurgitates to feed its babies, which are called squabs. Both parents produce crop milk, which sort of looks like cottage cheese. The babies can’t digest anything except crop milk for the first week of life, so the parents may actually not eat anything during the first days after the eggs hatch to make sure there aren’t any seeds mixed in with the crop milk. After a few days the parents mix in food that’s been softened in the crop.

Pigeons and doves are almost the only birds that produce crop milk. The flamingo and the male emperor penguin do too, even though they aren’t related to pigeons. But that’s it, as far as we know. So if anyone asks you what the flamingo, the emperor penguin, and the pigeon have in common, now you know. Also, they’re all birds.

Pigeons live in flocks, although the flock may break up into smaller groups or pairs during part of the day. At night the birds usually roost together except for pairs who have eggs or babies in a nest. Pigeons mate for life and both parents take care of the eggs and squabs. Flock leaders find food and lead the rest of the birds to it, whether the food comes from plants growing in a park or from a person scattering birdseed.

Pigeons are actually clean animals when they have access to water. They like to bathe and preen to keep their feathers clean. If you’ve ever watched a typical bird drink water, maybe at a puddle or a birdbath, you might have noticed that the bird dips some water into its beak, then tilts its head back so the water runs down its throat. This is because most birds can’t actually swallow water the way most mammals can. I mean, if you had to you could drink water while you were upside down, although you might choke or get it in your sinuses. But some of the water at least would get into your stomach. Birds couldn’t. Except for the pigeon, which can actually drink like a mammal, keeping its head down as it swallows. The pigeon and its close relatives are the only birds known who can do this.

No one thinks of pigeons as especially smart birds, but guess what. They’re actually pretty bright. Pigeons can easily memorize images, even hundreds of them, and retain those memories for years. They not only recognize individual humans, they can learn to understand what human expressions mean. They also have keen vision and can differentiate between very similar items or pictures, which leads to pigeons being trained to do something unexpected. Wait for it. You’re not going to believe this. Pigeons can learn to identify malignant breast tissue in mammograms at least as well as humans can. Researchers train birds to identify the differences in mammogram slides, then use four birds in a team. The team can be 99% accurate in identifying malignancies that need to be treated. So pigeons can save human lives!

Not only that, but researchers can find sources of lead pollution by taking blood samples from sick or dead pigeons found in cities. Since city pigeons generally have small territories that only encompass a few blocks, researchers can measure the level of lead found in birds and know roughly where the lead exposure occurred. That helps the city find and clean up sources of lead pollution.

Pigeons are actually quite healthy birds, despite their reputation as diseased. They’re surprisingly resistant to a lot of bird diseases, including bird flu. Many people think of pigeons as dirty scavengers, but like other urban animals, they’re just living out their lives in an environment humans made. And if they’re scavengers, just think about where that food is coming from. People are dropping it on the ground, that’s where. Maybe people are the dirty ones, throwing food around. Pigeons are just cleaning it up for us.

This is what a pigeon sounds like:

[pigeon sound]

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 137: The Orca, Jolly Terror of the Seas

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Thanks to Pranav for this week’s topic, the orca or killer whale!

Further reading:

https://www.nationalgeographic.com/animals/2019/07/killer-whales-orcas-eat-great-white-sharks/

Save Our Seas Magazine (I took the Jaws art below from here too)

An orca:

Orcas got teeth:

Starboard and Port amiright:

Show transcript:

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

This week let’s return to the sea for a topic suggested by Pranav, the orca. That’s the same animal that’s sometimes called the killer whale. While it is a cetacean, it’s more closely related to dolphins than whales and is actually considered a dolphin although it’s much bigger than other dolphin species.

The orca grows up to 26 feet long, or 8 meters, and is mostly black with bright white patches. The male has a large dorsal fin that can be 6 feet tall, or 1.8 meters, while females have much shorter dorsal fins that tend to curve backwards more than males’ do. Some orcas have lighter coloring, gray instead of black or with gray patches within the black.

The orca lives throughout the world’s oceans although it especially likes cold water. It eats fish, penguins and other birds, sea turtles, seals and sea lions, and pretty much anything else it can catch.

Everything about the orca is designed for strength and predatory skill. It has good vision, hearing, sense of touch, and echolocation abilities. It’s also extremely social, living in pairs or groups and frequently hunting cooperatively.

Some populations of orca live in the same area their whole lives, traveling along the same coastline as they hunt fish. These are called resident orcas and they’re closely studied since researchers can tell individuals apart by their unique markings, so can keep track of what individuals are doing.

Other populations are called transient because they travel much more widely. Transient and resident orcas avoid each other, so they may be separate species or subspecies, although researchers haven’t determined whether this is the case yet. There’s even a newly discovered population of orcas found off the tip of South America that may be a new species. Researchers are analyzing DNA samples taken from the South American orcas with little darts. Fishers had reported seeing odd-looking small orcas in the area for over a decade, but recent photos taken by tourists gave researchers a better idea of what they were looking for. The new orcas have rounder heads and different spotting patterns than other orca populations.

Transient orcas eat more mammals than resident orcas do. Resident orcas mostly eat fish. They have clever ways of catching certain fish, too. A pod of orcas can herd herring and some other fish species by releasing bubbles from their blowholes, which frighten the fish away. A group of orcas releasing bubbles in tandem can make the school of fish form a big ball for protection. Then each orca slaps the ball with its tail. This stuns or even kills some of the fish, which the orca then eats easily. Pretty clever. An orca may also stun larger fish by smacking it with its powerful tail flukes.

But the orca is also good at catching seals and sea lions. Some orcas learn to beach themselves safely when chasing seals, since the seal will often try to escape onto land. Another hunting technique is called wave-hunting, where a group of orcas swim in a way that causes waves to slop over an ice floe. Any animal or bird resting on the ice floe is washed into the water.

Because transient orcas mostly hunt mammals that can hear the orcas’ echolocation clicks and other vocalizations, they tend to stay silent while hunting so they don’t alert their prey. Resident orcas don’t have to worry about noise as much, since most of the fish they eat either can’t hear or their calls or don’t react to them. Resident orcas are much more vocal than transient orcas as a result.

But all orcas have calls they use socially. These are calls that help members of the pod stay in contact, help them coordinate hunting activities, and identify themselves to members of other pods. A pod is usually made up of several family groups, usually ones that are related in some way. You know, like the orca equivalent of an extended family—you and your mom and siblings, maybe your dad, and your mom’s sister and her babies, and so on. Each pod has its own dialect, with their own calls not heard in other pods.

Orcas are also incredibly intelligent and show social traits that match those of humans and chimpanzees, like playfulness, cooperation, and protectiveness. Their social structure is also complex and similar in many ways to those of humans and other great apes. As you may remember from episode 134 about the magpie, complex social structures lead to intelligence in individuals. Individual orcas have what’s known as signature whistles, a unique vocalization that only applies to that one orca. In other words, orcas have names. Researchers have also identified signature whistles in other dolphin species.

Because orcas are so large, so social, so intelligent, and travel such enormous distances every day—up to 50 miles, or 80 km—it doesn’t make any sense to keep them in captivity. But there are a lot of orcas in captivity. In the last decade or so people have started to realize that maybe this is not good for the orcas. Captive orcas develop mental and physical problems that they don’t have in the wild, including bad teeth. A 2017 study of captive orcas found that all of them had tooth problems and more than 65% of them had teeth so worn that the tooth pulp was exposed. That’s the sensitive part of your tooth, so you can imagine the agony this must cause the orca. It’s so bad that over 61% of the orcas studied had had the pulp removed from some of their teeth, which at least stops the pain but which leaves the orca more prone to infection and disease, plus weakens the tooth and can lead to it cracking. Such awful tooth problems mostly result from the orca chewing on concrete and steel in its tank, and this kind of chewing is due to extreme anxiety and other mental problems due to captivity. It’s not seen in orcas in the wild at all. So no, there shouldn’t be any orcas in captivity, or any other cetaceans, unless it’s for rehabilitation purposes with the goal of releasing the orca back into the wild after it’s healthy again.

The orca can live to be at least 90 years old, possibly older. Females especially live much longer than males overall. Female orcas lose the ability to have babies after about age 40 and enter a stage of life called menopause. Humans do this too, and studies show that it’s for the same reasons. Older females help younger females care for their children, and they’re also group leaders who teach younger orcas where to find food and how to catch it.

The orca is an apex predator, meaning there is nothing in the wild that hunts and eats it. Even the great white shark. On average the orca is larger than the great white, and it has an advantage because it hunts cooperatively. Where there are orcas around, there are usually not any great white sharks. This is partly because the two species eat the same thing and the orca out-competes the shark, but it’s also because the orca can and will eat great white sharks.

Some orcas have figured out that they can turn a shark upside down and keep it there in order to hypnotize it. This is called tonic immobility and researchers aren’t entirely sure why it happens, but the shark remains immobile until it wears off after a few minutes. It doesn’t work in all shark species or for every shark, but it makes the shark a lot easier for the orca to kill since it can’t fight back. In 1997 witnesses saw an orca hold a great white upside down for 15 minutes, trying to hypnotize it. It didn’t work, but since sharks have to keep moving to breathe, since they can’t pump water through their gills otherwise, the shark in question actually suffocated and the orca ate it.

But a pair of orcas have taken predation of great white sharks to a whole new level.

The phenomenon was first spotted in 1997 off the coast of San Francisco in western North America. People in a whale-watching tour saw two orcas attack a great white shark and eat its liver. Just its liver. They knew exactly where the liver was and aimed for it during the attack. A great white’s liver is huge and full of yummy fat.

Later that year, researchers studying elephant seals in the area noticed that all the great white sharks that usually preyed on seal colonies had vanished. They’d actually moved out of the area instead of staying to eat the seals. Studies of tagged great whites determined that they avoided orcas to the point of migrating away from feeding sites entirely if orcas were around.

Twenty years later, a marine biologist in South Africa named Alison Kock studied a pair of orcas named Starboard and Port who were attacking sharks the same way and eating their livers. Initially they targeted sevengill sharks, which can grow up to ten feet long, or 3 meters. But all the sevengill sharks fled and in 2017 the carcasses of great white sharks started to wash ashore with their livers eaten. Dr. Kock was pretty sure Starboard and Port were the culprits. When she studied the dead sharks, she recognized tooth marks from orcas.

Remember how earlier I said there were two types of orcas known, the residential and the transient groups? Plus the newly discovered group? Well, there’s actually a fourth group called the offshore orca. These are populations of orcas that live farther away from shore than most other groups. They travel widely and are the only orcas known in the wild to have teeth that are worn down flat almost like the captive orcas. Researchers think the offshore orcas specialize in hunting sharks and their relatives, and that the tooth wear comes from the sharks’ rough skin. Unlike the captive sharks, the tooth wear doesn’t affect the orcas’ overall health. Studies of offshore orcas have determined that more than 93% of their diet is made up of sharks.

Starboard and Port are now mostly after the bronze whaler shark, which grows up to 11 feet long, or 3.3 meters. No shark is safe.

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 136: Smallest of the Small

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Last week we learned about the smallest species of animals not typically thought of as small, like snakes and cetaceans. This week let’s look at some of the tiniest animals in the world, the smallest of the small!

Further watching:

A short video about jerboas. Really interesting and well-made!

A button quail:

Baby button quails are the size of BEES:

Kinglets are teeny birds even when grown up. Left, the golden-crowned kinglet. Right, the goldcrest. These birds MAY BE RELATED, you think?

The pale-billed flowerpecker, also teeny and with a cute name:

Moving on from birds, the pygmy jerboa is one of the smallest rodents in the world:

The Etruscan pygmy shrew is even tinier, probably the smallest known mammal alive today. Shown here with friend/lunch:

The Western pygmy blue butterfly is probably the smallest butterfly known:

But the pygmy sorrel moth is even smaller. Right: red marks left behind on a sorrel leaf eaten by its larvae:

One of the world’s teeniest frogs:

Show transcript:

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

Last week we learned about the smallest species of animals that aren’t typically thought of as small. But this week let’s learn about the smallest of the small animals. It’s like saying they’re the cutest of the cute animals. We’ll start with the bigger ones and get smaller and smaller as we go.

Let’s start with a bird. The smallest bird is the bee hummingbird, which we’ve talked about before. But there’s another bird that’s really small, the button quail. It’s about the size of a sparrow.

The button quail isn’t actually a quail, but it looks like one due to convergent evolution. There are a number of species in parts of Asia and Africa and throughout Australia. It generally lives in grasslands and is actually more closely related to shore and ocean birds like sandpipers and gulls than to actual quails, but it’s not very closely related to any other living birds. It can fly but it mostly doesn’t. Instead it depends on its coloring to hide it in the grass where it lives. It’s mostly brown with darker and lighter speckled markings, relatively large feet, and a little stubby nothing of a tail. It mostly eats seeds and other plant parts as well as insects and other invertebrates.

The button quail is especially interesting because the female is more brightly colored than the male, although not by much. In some species the female may have bright white markings, in some their speckled markings are crisper than the males. The female is the one who calls to attract a male and who defends her territory from other females. The female even has a special bulb in her throat that she can inflate with air to make a loud booming call.

The male incubates the eggs and takes care of the chicks when they hatch. Baby button quails are fuzzy and active like domestic chicken babies but they’re only about the size of a bumblebee. In many species, as soon as the female has laid her eggs, she leaves them and the male and goes on to attract another male for her next clutch of eggs.

People sometimes keep button quails as pets, specifically a species called the painted buttonquail or the Chinese painted quail. It’s about five inches long, or 12 cm. The female has black and white stripes on her face and throat. The birds can become quite tame and can live several years.

Button quails make a lot of different noises. This is what a button quail sounds like:

[button quail calls]

One of the smallest birds in the world that isn’t a hummingbird is the kinglet, with several species that live in North America and Eurasia. The goldcrest is a type of kinglet and the smallest European bird. It’s only 3.3 inches long, or 8.5 cm, although some individuals are larger. It looks a lot like the North American bird the golden-crowned kinglet, which is just a shade smaller at 3.1 inches, or 8 cm. Both species have a golden patch on the top of the head. The male also has an orangey spot in the middle of the golden patch. Both live in coniferous forests and eat insects and spiders.

Because kinglets are so small and active, they can starve to death quickly—in only an hour in some cases. Females lay up to 12 eggs at a time. TWELVE EGGS. That is a lot of eggs. The nest is too small to hold a dozen eggs in one layer so they end up in a pile. The female keeps all of them warm by pushing her legs down into the pile of eggs. Since her legs have a lot of blood vessels near the surface, they’re much warmer than most birds’ legs.

When the babies hatch, they stay in a pile. The ones on the top of the pile get fed first, naturally, but then they burrow down into the pile and push their siblings up toward the top. They’re not just being nice, though, since birds in the bottom of the pile stay warmer.

This is what a golden-crowned kinglet sounds like:

[bird call]

The pale-billed flowerpecker is even smaller than the kinglets and are among the smallest birds in Asia. It lives in parts of India and nearby areas and mostly eats berries, although it also eats flower nectar. It grows to only 3 inches long, or 8 cm, and is plain brownish-green in color with a short tail and shiny black eyes. It lives in forests but often visits gardens. It doesn’t lay a dozen eggs at a time, just an ordinary two or three.

This is what a pale-billed flowerpecker sounds like. These are some teeny sounds from teeny birds:

[bird call]

There are several rodents that are considered the smallest rodent, but we’re only going to learn about one of them today, the pygmy jerboa. On average it’s only 1.7 inches long, or 4.4 cm, not counting its extremely long tail.

The pygmy jerboa lives in the deserts of Pakistan and possibly in nearby areas too. It has very long hind legs and very short front legs so it hops like a tiny kangaroo, using its long tail as a way to balance and maneuver at high speeds. Its tail is twice as long as its body. Its large hind feet and the end of its tail are very furry to give it more surface area so it can easily maneuver through loose sand.

It mostly eats seeds and leaves, and it gets all the moisture it needs from the food it eats. It’s nocturnal and spends its days in the burrow it usually digs under bushes. Like many other tiny animals, when it rests it slows its metabolism drastically so it won’t starve to death while it’s asleep. Life is rough for tiny animals.

We don’t know a whole lot about the pygmy jerboa except that it’s endangered due to habitat loss, so let’s move on to an even smaller mammal.

The Etruscan shrew grows to about 1.6 inches long, or 4 cm, on average, not counting its short tail. The tail is about a third of the length of its body. It lives in southern Europe, parts of Asia, parts of the Arabian Peninsula, and northern Africa and prefers warm, moist climates. It’s the same size and weight as the bumblebee bat we talked about last week, so it’s one of the smallest mammals known.

The Etruscan pygmy shrew is pale brown with a lighter colored belly, a long nose, and short whiskers around its mouth that it uses to help it find its prey. It’s incredibly active and makes clicking noises almost constantly, as a way to alert other shrews that it’s there and is willing to defend its territory. It makes its nest among rocks and in the abandoned burrows of other animals.

Like the kinglets and other highly active, tiny animals, it has to eat a lot to keep its metabolism going—up to twice its own weight in food every day. It can also enter a torpid state where it reduces its body temperature and metabolism the same way the pygmy jerboa does, in order to not starve while it sleeps. But the Etruscan shrew doesn’t rest very often.

It mostly eats insects and other invertebrates like earthworms, but it will eat anything it can kill. This includes lizards, small rodents, and frogs. It especially likes grasshoppers and crickets, which are often as large as it is. In order to kill prey its own size, the shrew is incredibly fast. If you remember episode 82 where we talked about the star-nosed mole, the Etruscan shrew primarily hunts by touch and can react in barely 25 milliseconds when it touches something it wants to eat. It takes something like 300 milliseconds for a human to blink their eyes, if that gives you an idea of how fast the shrew is. It can touch a cricket and kill it in less time than it takes to blink.

So that’s as small as mammals get, as far as we know. What’s the smallest amphibian?

Well, it’s really, really small. The smallest known frog is only 7.7 mm long. Paedophryne amauensis isn’t just the smallest frog, it’s the smallest vertebrate known. It was only discovered in 2009 in Papua New Guinea.

It sounds like an insect and lives in the damp leaf litter on the forest floor, and it’s dark brown and black in color to blend in with dead leaves, so it was hard to find. Researchers only found it by using sensitive microphones to triangulate on its call, then quickly scooping up lots of leaf litter and stuffing it into plastic bags so anything living in the leaves couldn’t escape. Its eggs hatch into tiny froglets instead of tadpoles.

The tiniest frog is just about the same length as the tiniest fish, the stout infantfish that lives in a few coral reefs near Australia, including the Great Barrier Reef. It also grows 7.7 mm long on average, although females are typically longer and it can grow as much as 10 mm long. But the smallest known fish is the male of an anglerfish species that only grow 6.2 mm long. This doesn’t really count, though, since females grow up to two inches long, or 50 mm. Like other deep-sea anglerfish species, when a male of Photocorynus spiniceps finds a female, he bites her and stays there. Eventually his mouth actually fuses to her body and he lives the rest of his life as a sort of parasitic extension of the female. He supplies her with sperm to fertilize her eggs before she lays them, and she supplies him with nutrition and oxygen since he’s basically part of her body at that point. A female can have more than one male fused to her.

So, we seem to have reached the smallest vertebrates. What about the smallest insects and other invertebrates?

Butterflies are generally pretty small, but the smallest butterfly known is really, really small. The Western pygmy blue butterfly only has a wingspan of 20 mm at most but usually more like 12 mm across. That’s less than an inch. It lives in western North America and parts of the middle east, and has even been found on Hawaii. Its wings are a pretty coppery brown color with rows of black and white spots. It likes deserts and waste places where you wouldn’t expect to find anything as delicate as a tiny butterfly. Its caterpillars eat various types of weed plants.

That is pretty much it. There’s not much to this tiny butterfly. The real mystery is why it’s called the western pygmy blue when it’s not actually blue.

Compared to the smallest moth known, the western pygmy blue butterfly is a giant. The smallest moth is the pygmy sorrel moth and its wingspan is barely four millimeters. Its wings shade from silvery with a metallic bronze tint to purply with a white stripe, and gray along the ends. It’s really pretty but so tiny that it’s hard to spot. It lives in much of Europe and its larvae leave distinctive spiral shapes on sorrel leaves as it eats.

We’ll come back to insects in a minute or two, but let’s look at a few snails first. The smallest land snail is the Borneo snail. Its shell is only .7 of a mm high. It was only discovered in 2015. We don’t know a lot of about it yet, but it probably eats bacterial film growing on limestone in caves. So far researchers haven’t even found a living Borneo snail, though, just its shells.

The smallest water snail is even smaller than the Borneo snail. It’s from North America and its shell is only half a millimeter across at the most. Some individuals are only .3 mm across. Ammonicera minortalis lives in shallow water off the coast of southern Florida and around Cuba and other islands in that area. And that’s pretty much all we know about it. It’s a lot easier to study bigger animals just because they’re easier to find.

Small as that is, on average the smallest beetle is smaller than the smallest snail. It’s a type of featherwing beetle only described in 1999, and on average it’s .338 mm long. So far it’s only been found in Central America and it eats fungus. It’s yellowish-brown in color but that doesn’t really matter because it’s so small that you need a magnifying glass to really see it.

Once you start dividing millimeters, you’re getting into ridiculously tiny territory. But the smallest insect is a type of wasp known as a fairyfly. Kikiki huna is so small it’s measured in micrometers, sometimes called microns, and is smaller than some single-celled organisms. It’s only 150 micrometers long, which is shorter than an ordinary piece of printer paper is thick. It’s been found on Hawaii, Costa Rica, and Trinidad but it probably lives in other places but just hasn’t been found yet. Some researchers suspect that it’s as small as a flying animal can become without losing the ability to fly under its own power instead of just floating on the wind.

At this point anything smaller than Kikiki huna and its close relatives are made up largely of bacteria, which are frankly not as cute or as interesting as, say, button quail. So let’s finish with what may be the very smallest living organism ever found. Or it may not be. Because researchers are literally not even sure if the nanobe is even alive.

In 1996 researchers found what looked like filiments growing among rock samples collected from wells off the Australian coast. Some of them were only 20 nanometers in diameter. To put that into perspective, a nanometer is one billionth of a meter. That’s billion with a B. It’s one thousandth of a micrometer. A nanobe is a tenth of the size of the smallest known bacteria.

The researchers weren’t sure what they’d found so they did a lot of tests. They thought they might have discovered a new kind of crystal, but when they stained the nanobes with a type of dye that binds to DNA, the results indicated the nanobes might be living organisms. But no DNA has been successfully recovered from nanobes.

There’s still a lot of research to be done to determine what they are and if they’re actually alive, though. The main problem is that nanobes appear to be too small to contain all the things that living organisms need. But they do resemble fungi in some ways, just much, much smaller. If nanobes are alive, they’re extremely different from any living animal ever known and presumably live and reproduce in ways completely unlike all other life.

But here’s an interesting note. In 1996 researchers found structures inside a meteorite from Mars that look a lot like nanobes.

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 135: Smallest of the Large

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This week we’re looking at some very small animals–but not animals that we think of as small. Join us for a horrendously cute episode!

Further reading:

The Echinoblog

Further listening:

Animals to the Max episode #75: The Sea Panda (vaquita)

Varmints! episode #49: Hippos

Further watching:

An adorable baby pygmy hippo

The Barbados threadsnake will protecc your fingertip:

Parvulastra will decorate your thumbnail:

Berthe’s mouse lemur will defend this twig:

The bumblebee bat will eat any bugs that come near your finger:

The vaquita, tiny critically endangered porpoise:

The long-tailed planigale is going to steal this ring and wear it as a belt:

He höwl:

A pygmy hippo and its mother will sample this grass:

This Virgin Islands dwarf gecko will spend this dime if it can just pick it up:

Show transcript:

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

I talk a lot about biggest animals on this podcast, so maybe it’s time to look at the very smallest animals. I don’t mean algae or bacteria or things like that, I mean the smallest species of animals that aren’t usually considered especially small.

We’ll start with the smolest snek, the Barbados threadsnake. It only lives on a few islands in the Caribbean, notably Barbados. The very largest individual ever measured was only 4.09 inches long, or 10.4 cm, but most are under four inches long. But it’s an extremely thin snake, not much thicker than a spaghetti noodle.

The Barbados threadsnake mostly eats termites and ant larvae. It spends most of its time in leaf litter or under rocks, hunting for food. The female only lays one single egg, but the baby is relatively large, about half the mother’s length when it hatches.

That’s so cute. Why are small things so cute?

Remember the starfish episode where we talked about the largest starfish? Well, what’s the smallest starfish? That would be Parvulastra parvivipara, which is smaller than a fingernail decoration sticker. It grows to about ten millimeters across and is orangey-yellow in color. It lives on the coast of Tasmania in rock pools between low and high tide, called intertidal rock pools.

If you remember the Mangrove killifish from a few episodes ago, you’ll remember how killifish females are hermaphrodites that produce both eggs and sperm, and usually self-fertilize their eggs to produce tiny clones of themselves. Well, Parvulastra does that too, although like the killifish it probably doesn’t always self-fertilize its eggs. But then it does something interesting for a starfish. Instead of releasing its eggs into the water to develop by themselves, Parvulastra keeps the eggs inside its body. And instead of the eggs hatching into larvae, they hatch into impossibly tiny miniature baby starfish, which the parent keeps inside its body until the baby is big enough to survive safely on its own.

But what do the baby starfish eat while they’re still inside the mother? Well, they eat their SIBLINGS. The larger babies eat the smaller ones, and eventually leave through one of the openings in the parent’s body wall, called gonopores. Researchers theorize that one of the reasons the babies leave the parent is to escape being eaten by its siblings. And yes, occasionally a baby grows so big that it won’t fit through the gonopores. So it just goes on living inside the parent.

Next, let’s look at the smallest primate. The primate order includes humans, apes, monkeys, and a lot of other animals, including lemurs. And the very smallest one is Berthe’s mouse lemur. Its body is only 3.6 inches long on average, or 9.2 cm, with a tail that more than doubles its length. Its fur is yellowish and brownish-red.

Berthe’s mouse lemur was only discovered in 1992. It lives in one tiny area of western Madagascar, where it lives in trees, which means it’s vulnerable to the deforestation going on all over Madagascar and is considered endangered.

It mostly eats insects, but also fruit, flowers, and small animals of various kinds. Its habitat overlaps with another small primate, the gray mouse lemur, but they avoid each other. Madagascar has 24 known mouse lemur species and they all seem to get along well by avoiding each other and eating slightly different diets. Researchers discover new species all the time, including three in 2016.

Last October we had an episode about bats, specifically macrobats that have wingspans as broad as eagles’. But the smallest bat is called the bumblebee bat. It’s also called Kitti’s hog-nosed bat, but bumblebee bat is way cuter. It’s a microbat that lives in western Thailand and southeast Myanmar, and like other microbats it uses echolocation to find and catch flying insects. Its body is only about an inch long, or maybe 30 millimeters, although it has a respectable wingspan of about 6 ½ inches, or 17 cm. It’s reddish-brown in color with a little pig-like snoot, and it only weighs two grams. That’s just a tad more than a single Pringle chip weighs.

Because the bumblebee bat is so rare and lives in such remote areas, we don’t know a whole lot about it. It was only discovered in 1974 and is increasingly endangered due to habitat loss, since it’s only been found in 35 caves in Thailand and 8 in Myanmar, and those are often disturbed by people entering them. The land around the caves is burned every year to clear brush for farming, which affects the bats too.

The bumblebee bat roosts in caves during the day and most of the night, only flying out at dawn and dusk to catch insects. It rarely flies more than about a kilometer from its cave, or a little over half a mile, but it does migrate from one cave to another seasonally. Females give birth to one tiny baby a year. Oh my gosh, tiny baby bats.

So what about whales and dolphins? You know, some of the biggest animals in Earth’s history? Well, the vaquita is a species of porpoise that lives in the Gulf of California, and it only grows about four and a half feet long, or 1.4 meters. Like other porpoises, it uses echolocation to navigate and catch its prey. It eats small fish, squid, crustaceans, and other small animals.

The vaquita is usually solitary and spends very little time at the surface of the water, so it’s hard to spot and not a lot is known about it. It mostly lives in shallow water and it especially likes lagoons with murky water, properly called turbid water, since it attracts more small animals.

Unfortunately, the vaquita is critically endangered, mostly because it often gets trapped in illegal gillnets and drowns. The gillnets are set to catch a different critically endangered animal, a fish called the totoaba. The totoaba is larger than the vaquita and is caught for its swim bladder, which is considered a delicacy in China and is exported on the black market. The vaquita’s total population may be no more than ten animals at this point, fifteen at the most, and the illegal gillnets are still drowning them, so it may be extinct within a few years. A captive breeding plan was tried in 2017, but porpoises don’t do well in captivity and the individuals the group caught all died. Hope isn’t lost, though, because vaquita females are still having healthy babies, and there are conservation groups patrolling the part of the Gulf of California where they live to remove gill nets and chase off fishing boats trying to set more of the nets.

If you want to learn a little more about the vaquita and how to help it, episode 75 of Corbin Maxey’s excellent podcast Animals to the Max is an interview with a vaquita expert. I’ll put a link in the show notes.

Next, let’s talk about an animal that is not in danger of extinction. Please! The long-tailed planigale is doing just fine, a common marsupial from Australia. So, if it’s a marsupial, it must be pretty big—like kangaroos and wallabies. Right? Nope, the long-tailed planigale is the size of a mouse, which it somewhat resembles. It even has a long tail that’s bare of fur. It grows to 2 ½ inches long not counting its tail, or 6.5 cm. It’s brown with longer hind legs than forelegs so it often sits up like a tiny squirrel. Its nose is pointed and it has little round mouse-like ears. But it has a weird skull.

The long-tailed planigale’s skull is flattened—in fact, it’s no more than 4 mm top to bottom. This helps it squeeze into cracks in the dry ground, where it hunts insects and other small animals, and hides from predators.

The pygmy hippopotamus is a real animal, which I did not know until recently. It grows about half the height of the common hippo and only weighs about a quarter as much. It’s just over three feet tall at the shoulder, or 100 cm. It’s black or brown in color and spends most of its time in shallow water, usually rivers. It’s sometimes seen resting in burrows along river banks, but no one’s sure if it digs these burrows or makes use of burrows dug by other animals. It comes out of the water at night to find food. Its nostrils and eyes are smaller than the common hippo’s.

Unlike the common hippo, the pygmy hippo lives in deep forests and as a result, mostly eats ferns, fruit, and various leaves. Common hippos eat more grass and water plants. The pygmy hippo seems to be less aggressive than the common hippo, but it also shares some behaviors with its larger cousins. For instance, the pooping thing. If you haven’t listened to the Varmints! Episode about hippos, you owe it to yourself to do so because it’s hilarious. I’ll put a link in the show notes to that one too. While the hippo poops, it wags its little tail really fast to spread the poop out across a larger distance.

Also like the common hippo, the pygmy hippo secretes a reddish substance that looks like blood. It’s actually called hipposudoric acid, which researchers thinks acts as a sunscreen and an antiseptic. Hippos have delicate skin with almost no hair, so its skin dries out and cracks when it’s out of water too long.

The pygmy hippo is endangered in the wild due to habitat loss and poaching, but fortunately it breeds successfully in zoos and lives a long time, up to about 55 years in captivity. For some reason females are much more likely to be born in captivity, so when a male baby is born it’s a big deal for the captive breeding program. I’ll put a link in the show notes to a video where you can watch a baby pygmy hippo named Sapo and his mother. He’s adorable.

Finally, let’s finish where we started, with another reptile. The smallest lizard is a gecko, although there are a lot of small geckos out there and it’s a toss-up which one is actually smallest on average. Let’s go with the Virgin Islands dwarf gecko, which lives on three of the British Virgin Islands. It’s closely related to the other contender for smallest reptile, the dwarf sphaero from Puerto Rico, which is a nearby island, but while that gecko is just a shade shorter on average, it’s much heavier.

The Virgin Islands dwarf gecko is only 18 mm long not counting its tail, and it weighs .15 grams. A paperclip weighs more than this gecko. It’s brown with darker speckles and a yellow stripe behind the eyes. Females are usually slightly larger than males. Like other geckos, it can lose its tail once and regrow a little stump of a tail.

The Virgin Islands dwarf gecko lives in dry forests and especially likes rocky hills, where it spends a lot of its time hunting for tiny animals under rocks. We don’t know a whole lot about it, but it does seem to be rare and only lives in a few places, so it’s considered endangered. In 2011 some rich guy decided he was going to release a bunch of lemurs from Madagascar onto Moskito Island, one of the islands where the dwarf gecko lives. Every conservationist ever told him oh NO you don’t, rich man, what is your problem? Those lemurs will destroy the island’s delicate ecosystem, drive the dwarf gecko and many other species to extinction, and then die because the habitat is all wrong for lemurs. So Mr. Rich Man said fine, whatever, I’ll take my lemurs and go home. And he did, and the dwarf gecko was saved.

Look, if you have so much money that you’re making plans to move lemurs halfway across the world because you think it’s a good idea, I can help take some of that money off your hands.

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 134: The Magpie

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Thanks to Emma for this week’s suggestion about the magpie! We’ll learn all about the magpie and also about the mirror test for intelligence and self-awareness.

The black-billed magpie of North America (left) is almost identical in appearance to the Eurasian magpie (right):

Not all magpies are black and white. This green magpie is embarrassed by its goth cousins:

The beautiful and altruistic azure-winged magpie:

Chimps pass the mirror test. So do magpies:

The Australian magpie, or as Emma calls it, MURDERBIRD:

Show transcript:

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

This week let’s learn about the magpie, a frighteningly intelligent bird. Thanks to Emma for the suggestion!

The magpie is a member of the corvid family, so it’s related to crows, ravens, jackdaws, jays, rooks, and a few other kinds of birds. Most magpies are native to Europe and Asia, but there are a couple of species found in western North America. There are also two species found in Australia, but we’ll come back to those later on. People think of magpies as black and white, but some Asian species are green or blue. They look like parrots at first glance.

The most well-known magpie is the Eurasian or common magpie. Its body and shoulders are bright white and its head, tail, wings, beak, and legs are a glossy black. It has a very long tail for its size, a little longer than its body, and its wingspan is about two feet across, or 62 cm. It looks so much like the black-billed magpie of western North America that for a long time people thought the two birds were the same species.

Like most corvid species, the magpie is omnivorous. It will eat plant material like acorns and seeds, insects and other invertebrates, the eggs and babies of other birds, and roadkill and other carrion. It will also hunt small animals in groups. It mates for life and is intensely social.

The big thing about the magpie is how intelligent it is. It’s a social bird with a complex society, tool use, excellent memory, and evidence of emotions usually only attributed to mammals, like grief. An experiment with a group of Azure-winged magpies, a species that lives in Asia, shows something called prosocial behavior, which is incredibly rare except in humans and some other primates. Prosocial behavior is also called altruism. In the experiment, a magpie could operate a seesaw to deliver food to other members of its flock, but it wouldn’t get any food itself. All the magpies tested in this way made sure their bird buddies got the food. When access to the food was blocked for the other birds, the bird operating the seesaw didn’t operate it.

The magpie also passes what’s called the mirror test. The mirror test is when a researcher temporary places a colored dot on an animal’s body in a place where it can’t see it, usually the face. Then a mirror is introduced into the animal’s enclosure. If an animal sees the dot in the reflection and investigates its own body to try to examine or remove the dot, the researcher concludes that the animal understands that the reflection is itself, not another animal.

This sounds simple because most humans pass the mirror test when we’re still just toddlers. But most animals don’t. Obviously researchers haven’t been able to try the test with every single animal in the world, but even so, the results they’ve found have been surprising. Great apes pass the test, bottlenose dolphins and orcas have passed, and the European magpie has passed the test. Cleaner wrasse fish also passed the test.

You know what else passed the mirror test? Ants.

The mirror test is supposed to be a test of self-awareness, but that’s not necessarily what it’s showing. Dogs fail the mirror test but pass other tests that more clearly indicate self-awareness. But in dogs, the sense of smell is much more important than sight. Humans don’t even usually think of smell since we’re more attuned to sight and hearing, so we’ve constructed a flawed test without realizing it.

Gorillas also don’t always pass the mirror test, but researchers think this may be because in gorilla society, it’s an act of aggression to look into another gorilla’s eyes. So the gorilla looking in the mirror may literally not see the dot that was painted on its forehead while it was asleep, since it automatically avoids looking at another gorilla’s face, even its own reflection. As far as I can find, no one has tried painting the dot on bottom of the gorilla’s foot or something instead of its face.

Parrots, monkeys, lesser apes, and octopuses don’t pass the test, but all these animals express intelligence in many other ways. Not only that, but some animals that don’t technically pass the test because they don’t give any attention to the dot painted on them will use the mirror for other purposes, like looking at parts of the body they can’t ordinarily see. Asian elephants do poorly on the mirror test, but do well in other tests that measure self-awareness.

Also, most of the animals given the mirror test have never looked in a mirror before. Maybe they don’t realize that dot wasn’t always on their cheek. Or maybe they just don’t care if they’ve got a dot on their face.

That brings us to a final criticism of the mirror test. Some animals live in environments where they’re likely to see reflections. An animal that frequently sees its own reflection in still water when it drinks is more likely to understand that this is a reflection of itself. An animal that has never seen its own reflection won’t necessarily understand what it is. Even humans have this trouble. People who have been blind since birth but who regain vision later in life often don’t know what a reflection is at first. This doesn’t mean they’re stupid or not self-aware, it’s just something new that they have to learn.

But it’s still interesting that magpies pass the mirror test. Okay, let’s move on.

There are a lot of folklore traditions and superstitions about magpies. In Britain, seeing a single magpie is sometimes said to be bad luck, a sign of bad weather to come, or even an omen of death. Seeing two magpies is good luck or a good omen. In parts of Asia all magpies are considered lucky. The nursery rhyme “one for sorrow, two for joy” is originally about magpies, although as a kid I learned it about crows since I live in a part of the world where we don’t have magpies. The rhyme varies, but the version I learned is “one for sorrow, two for joy, three for a girl, four for a boy, five for silver, six for gold, and seven’s a secret that’s never been told.”

Magpies are supposed to be attracted to shiny objects and are thought of as thieves. There’s a whole opera about this, Rossini’s La Gazza Ladra, about a girl who’s accused of stealing a silver spoon. The girl is convicted and condemned to death, but just in time the spoon is discovered in a magpie’s nest and the girl is pardoned. You’ve probably heard the overture to this opera without knowing it, since it appears in a lot of movies.

But do magpies really steal shiny things like jewelry, coins, and silver spoons? Results of a study of wild common magpies indicate that they don’t. A few of the magpies investigated the shiny objects, but none took any and most birds were wary of getting too close to items they’d never seen before.

Many people think magpies are pests who chase off or kill other songbirds, steal things, and are basically taking over the world. That’s actually not the case. The magpie is an important part of its ecosystem, and areas with plenty of magpies actually have healthier populations of other songbirds. The black-billed magpie of North America will hang around herds of cattle, cleaning the animals of ticks and other insects.

Let’s return now to the Australian magpies I mentioned earlier. The black magpie is mostly black with white on its wings. It’s actually not closely related to the magpie at all but is a species of treepie. Other treepies are found in southeast Asia. Treepies are corvids, but they’re not closely related to magpies although they look similar.

The Australian magpie also looks similar to the common magpie, but it’s not a corvid, although its family is distantly related to the corvid family. It’s mostly black with white markings and a heavy silvery-white bill with a black tip. It lives in Australia, southern New Guinea, and has been introduced to New Zealand, where it’s an invasive pest that displaces native birds. It’s about the size of the common magpie, but more heavily built with a shorter tail. It mostly eats insects and other invertebrates, but it is omnivorous. Researchers have noticed that some Australian magpies dunk insects in water before eating them, a practice seen in many species of birds. It doesn’t just dip the insect in the water, though, it thrashes it around. Researchers theorize that this helps rid certain insects of toxins and therefore improves the taste.

If someone gets too close to an Australian magpie’s nest, it will divebomb them, especially the male. It may also peck at the face, sometimes causing injuries. Sometimes people will paint eyes on the back of a hat to try and fool a magpie into attacking the painted face instead of their actual face, although this generally doesn’t work. The magpie especially attacks people who are moving fast, like joggers and bicyclists, so some bike helmets have spikes on them to stop magpies from diving at them. But since a magpie will also sometimes land on the ground in front of a person, then fly up and attack their face from that angle, it doesn’t really matter what kind of hat you wear. It’s probably safest to avoid magpies who are nesting. The babies will be grown and flown away soon enough and then you can have your public park back.

Australian magpies also chase off predatory birds, mobbing them the same way crows and other birds mob hawks.

The Australian magpie is also an intelligent bird. Researchers think intelligence in birds and animals of all kinds is linked to sociability, and Australian magpies are just as social as their far-distant Eurasian and North American cousins. Magpies who grow up in larger groups score higher on tests of intelligence than magpies from smaller groups. The larger a group, the more complex the social interactions required of an individual bird, which drives cognitive development.

The Australian magpie has an amazing singing voice and can mimic other birds and animals. It even sometimes imitates human speech. A magpie may sing constantly for over an hour at a time, and pairs often call together. These duets actually indicate to other birds that the pair is working together to defend their territory, so maybe if you hear it it’s time to put on the bike helmet with spikes.

This is what an Australian magpie sounds like:

[magpie call]

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 133: The mangrove killifish and the unicorn pig

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This week’s (short) episode is about two animals that should have been in the strangest small fish and weird pigs episodes, respectively. I left them out by accident but they’re so interesting that they deserve an episode all to themselves anyway. Thanks to Adam for suggesting the mangrove killifish!

Further reading:

25 Years in the Mud: How a Quirky Little Fish Changed My Life

The mangrove killifish just looks normal:

Not a unicorn pig (okay yes technically a unicorn pig):

Unicorn pig skull:

Show transcript:

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

A few weeks ago we had an episode about strange small fish. Shortly after that episode released, I was going through my disorganized ideas and suggestions file and realized I’d left out one of the best weird small fish ever, a suggestion by Adam. I also discovered I’d missed an extinct pig I’d planned to include in the recent weird pigs episode. So let’s play catch up in a short episode and learn about both this week.

The fish Adam suggests is called the mangrove killifish, also called the mangrove rivulus, which lives in parts of Florida and Mexico, down to Central and South America. It’s technically a marine fish, meaning it lives in salt-water, but it also likes brackish water, that’s less salty than the ocean, and occasionally it even lives in freshwater. It especially likes mangrove swamps. It grows up to 3 inches long, or 7.5 cm and is a mottled brown in color with an eye spot on its tail. It doesn’t look like anything special.

But the mangrove killifish has a lot in common with amphibians, especially the lungless salamanders. Many types of salamander absorb air through the skin instead of through lungs or gills. The mangrove killifish does this too. It often lives in abandoned crab holes, which may not have very high quality water. But that’s okay, because it can absorb air through its skin and can live out of the water for well over a month as long as its skin stays damp. It’s sometimes found in places where you wouldn’t expect to find a fish, like the inside of rotting logs or buried in damp dead leaves.

So how does the killifish get into the rotting logs or the leaf litter or the crab burrows that aren’t connected to waterways? It actually uses its tail to flip itself out of the water and onto land, and then it continues to flip here and there until it finds a place where it wants to live for a while. It can direct this jumping, not just flop around like most fish out of water, and can jump several times its own length.

A lot of times when the tide goes out, fish get trapped in crab holes, dimples in the sand or mud, and other shallow water. That’s okay if the tide comes back in far enough to re-submerge the holes, but if the water doesn’t quite reach, it’s not long before fish start to suffocate as all the oxygen in the water is used up. But the killifish doesn’t have that problem. It just flips itself out of the water. It can also leave the water if it gets too hot.

The killifish is also territorial in water, which requires a lot of energy. When it’s out of the water, or in a little temporary pool or a crab burrow where it doesn’t have to worry about other killifish, it can relax. On the other hand, it loses a lot of weight while it’s out of the water since it doesn’t eat as much. So there are trade-offs.

Even the killifish’s eggs can survive out of water. The fish usually lays its eggs in shallow water, sometimes even on land that’s just near water. The eggs continue to develop just fine, in or out of water, but they delay hatching until they’re submerged.

And that leads us to the most astonishing thing about the mangrove killifish. In most populations, almost all killifish are females, and most of the time they don’t need a male fish to fertilize their eggs. Females produce eggs but they also produce sperm that fertilize the eggs before they’re even laid. The eggs hatch into genetic duplicates of the parent—clones, basically. The term for an organism that produces both eggs and sperm is hermaphrodite, and while it’s common in some invertebrates, the killifish is the only known vertebrate hermaphrodite. Vertebrate, of course, is an animal with a backbone.

But while most killifish are females, there are occasionally males. Male killifish are orangey in color. When a male is around, females suppress their ability to self-fertilize eggs and they lay the eggs for the male to fertilize, just like any other fish. This helps keep the species genetically diverse and able to adapt to external pressures like increased numbers of parasites.

Next, let’s talk about the unicorn pig. Or pigicorn, if you like. It’s called Kubanochoerus [koo-ban-oh-ko-rus] and there were several species. It was related to modern pigs and lived throughout most of Eurasia and parts of Africa around 10 million years ago.

It was big, up to four feet tall at the shoulder, or 1.2 meters, and had tusks like other pigs. It probably looked a lot like a wild boar. But its skull is longer than modern pig skulls and it had horns. Three horns, specifically. Two of the horns were small and grew above the eyes, while a bigger horn grew forward from its forehead. The forehead horn wasn’t very long and was probably blunt. Researchers used to think males used these forehead horns to fight each other, but females had them too so they may also have been used for defense from predators.

That is literally all I can find out about this fascinating animal. I can’t even speculate about the horns since literally no other pig has horns, at least that I can find. Presumably the warty protrusions that many modern pig species have are similar to the horns that Kubanochoerus had. The eyebrow horns might have had the same purpose as the facial protrusions on warthogs and other pigs, as a way to protect the eyes when the pigs fight. The forehead horn, though…well, that’s just weird. It probably wasn’t covered with keratin, but we don’t know. My own guess is that it was something more like an ossicone and was covered with skin and hair. But again, we don’t know. Not until we invent a working time machine and go back to look at one.

That’s it, a very short episode. I’m actually in Dublin, Ireland right now attending WorldCon, so while I’m here I will keep an eye out for leprechauns, fairies, and pigicorns, just in case.

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!