Category Archives: birds

Episode 173: The Mystery of the Forest Raven

We have a fun mystery bird this week, the forest raven! Was it a real bird??? (hint: yes, but not a raven)

The “forest raven” illustration from Swiss naturalist Conrad Gessner’s Historiae Animalium, published in 1555:

Scans of the original pages about the forest raven. It’s written in Latin:

The Northern bald ibis. Wacky hair!

Flying bald ibises:

Further viewing:

This Weird Bird May Have Been the First Protected Species

Show transcript:

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

It’s high time we had a mystery animal episode, so this week we’re going to learn about a mystery bird, one with a satisfying conclusion.

The story starts almost 470 years ago, when a scholar and physician named Conrad Gessner, who lived in Switzerland, published a book called Historia animalium. The book wasn’t like the medieval bestiaries of previous centuries, in which fantastical and real animals were listed together and half the information consisted of local superstitions. Gessner was an early naturalist, a scientist long before the term was in general use. Historia animalium consisted of five volumes with a total of more than 4,500 pages, and in it Gessner attempted to describe every single animal in the world, drawing from classical sources such as Pliny the Elder and Aristotle as well as his own observations and study.

The book contained animals that had only recently been discovered by Europeans at the time, including animals from the Americas and the East Indies. It also included a few entries which no one today believes ever existed, like the fish-like sea monk and sea bishop. Those and similar monsters were probably added by Gessner’s publishers against his will or maybe just without him knowing, since he was seriously ill by the time the volume on fish was published. For the most part, the book was as scholarly as was possible in the mid-16th century and was lavishly illustrated too.

Volume three, about birds, was published in 1555, and it included an entry for a bird Gessner called the waldrapp, or forest raven. But the illustration didn’t look anything like a raven. The bird has a relatively long neck, a crest of feathers on the back of its head, and a really long bill that ends in a little hook. Gessner wrote that the bird was found in Switzerland and was good to eat.

In fact, I spent an entire morning finding the original scanned pages of a copy of the forest raven entry, typing them as well as I could and modernizing the spelling where I knew how, and using Google translate from Latin to English. The results were…not entirely coherent. Then, after I’d done all that, I continued my research, and that included watching a short BBC film about the bird–which included part of the translation! So I transcribed it. Here’s a translation cobbled together from the BBC’s translation and other parts of the passage that me and Google translate could figure out:

“The bird is generally called by our people the Waldrapp, or forest raven, because it lives in uninhabited woods where it nests in high cliffs or old ruined towers in castles. Men sometimes rob the nests by hanging from ropes. It acquires a bald head in its age. It is the size of a hen, quite black from a distance, but if you look at it close, especially in the sun, you will consider it mixed with green. The Swiss forest raven has the body of a crane, long legs, and a thick red bill, slightly curved and six inches long. Its legs and feet are longer than those of a chicken. Its tail is short, it has long feathers at the back of its head, and the bill is red. The bill is suited for poking in the ground to extract worms and beetles which hide themselves in such places. It flies very high and lays two or three eggs. The young ones are also praised as an article of food and are considered a great delicacy, for they have lovely flesh and soft bones. Those who rob the nests of young take care to leave one chick so the parents will return the following year.”

All that sounds like a perfectly ordinary bird, although not a raven. But what was it? That’s the problem. No one knew, and eventually scholars decided that Gessner must have included a bird that didn’t exist.

But it did sound like one particular bird, just not one related in any way to the raven and not one that lived in Switzerland or other parts of Europe. That’s the northern bald ibis, which was once common across the Middle East and northern Africa.

Here’s a description of the Northern bald ibis. Let’s see how it matches up with Gessner’s forest raven.

The Northern bald ibis is a fairly large bird, about a foot long, or 31 cm, with a wingspan of four and a half feet, or 135 cm. That’s about the size of a goose. It has black feathers that shine with iridescent colors in sunlight, including bronze, violet, and green. It has long, dull red legs and a long, curved bill that’s also reddish. Its head is the same shade of dull red and has no feathers, but it does have a crest of long feathers on the back of its head and neck. It nests on cliff ledges and prefers to hunt for food in areas where the grass or other vegetation is short, such as pastures, fallow fields, semi-arid steppes, and golf courses, often ten miles or more from the cliffs where it nests, or 15 km. It eats insects and other small invertebrates, but it especially likes lizards and beetles. It probes into soft, sandy soil with its bill to find most of its food. The birds live in small flocks and often fly in a V formation.

The northern bald ibis mates for life. The male finds a good nesting site and tidies it up, then waits to see if he can attract a female. The female inspects the site and the male to decide if she likes them, and if she does, the pair build a nest of twigs lined with grass, and the female lays two to four eggs.

Oh, and the northern bald ibis is sometimes also called the waldrapp, just as Gessner reported.

All this information certainly sounds like the same bird Gessner described. But the northern bald ibis doesn’t live in Switzerland or other parts of Europe. It’s only known from the Middle East and northern Africa. Right?

That’s what people after Gessner thought, until 1941. That’s when a team of scientists excavating ancient sites in Switzerland found the bones of what turned out to be northern bald ibises—but the bones weren’t fossilized. They were only a few hundred years old. More remains, both fossil and subfossil, have since been found in France, Germany, Austria, and Spain, and the bird probably lived in even more areas.

It turns out that the northern bald ibis was once common in many parts of Europe, especially around the Alps. It was considered a sacred bird in ancient Egypt, and was supposed to be one of the birds released by Noah during the great flood to help him find land, so was venerated by people of different faiths in the Middle East. But in Europe, it was just considered good to eat. The Archibishop Leonard of Salzburg called for its protection in the Swiss Alps as long ago as 1504, but by the early 17th century, only a matter of decades after Gessner’s book was published, the bird was extinct in Europe. It didn’t take long for Europeans to forget it even existed.

Unfortunately, the northern bald ibis is still endangered due to hunting, habitat loss, and poisoning from pesticides. It’s also sometimes electrocuted when it lands on electricity pylons that aren’t insulated for birds, although efforts are underway to make pylons bird-safe in many areas. A successful captive breeding program has been in place since the late 1970s, though, and that’s a good thing, since the last migratory population went extinct in 1989 and the remaining non-migratory colonies declined to only a few hundred individuals.

The breeding program has gone so well that birds started being reintroduced in some areas of their former range in about 2003, including Spain, Germany, Austria, and Italy. Tagging of the remaining wild birds has also revealed that a small population still migrates from the Middle East to Africa to winter in central Ethiopia. In some areas, conservationists have added nesting platforms to the existing cliffs so that more birds can nest safely. Hopefully their numbers will continue to climb.

I’ll finish with a final piece of trivia about the northern bald ibis that I think you’ll like. It’s a member of the pelican family. Have a nice day.

You can find Strange Animals Podcast online at That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at If you like the podcast and want to help us out, leave a rating and review on Apple Podcasts or wherever you listen to podcasts. We also have a Patreon at if you’d like to support us that way.

Thanks for listening!

Episode 171: The Animals of St. Kilda

Thanks to Emma for the suggestion! Let’s learn about some animals that live on the St. Kilda islands off the coast of Scotland!

St. Kilda:

Soay rams (kept on farms, not the feral sheep):

A small flock of Soay sheep (these are from a farm too):

A Boreray ram (on a farm):

A Boreray ewe with her babies (also on a farm, or at least I think so):

The St. Kilda wren (not a sheep):

The St. Kilda field mouse (also not a sheep) is the size of a hamster:

Show transcript:

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

This week’s episode is a suggestion from Emma, who long ago told me about the interesting history and unique animals of the island of St. Kilda in Scotland. I’ve been meaning to cover it ever since, so finally I’m getting around to it after only two years or so.

Emma says, “It’s an amazing little island and sort of a reverse of the usual ‘humans cause extinction’ story. The humans on the island went ‘extinct’, being evacuated from the island partly because increased mainland human contact was bringing illnesses they couldn’t fight without hospitals. Two lots of rad ancient sheep and some unique wrens and mice are happily living there to this day.”

St. Kilda is not one but a group of islands off the coast of Scotland, but the largest island and the only one where people once lived is called Hirta. In 1930, everyone who still lived there moved to the mainland, but by that time hardly anyone remained on St. Kilda anyway. The island probably never had more than a few hundred people in residence at any given time. In 1957 St Kilda was designated as a nature reserve and in 1986 as a World Heritage Site.

Since then, as Emma says, the animals of the islands have mostly been left alone. This includes two breeds of sheep that were left behind on two of the smaller islands when the last residents moved away.

One of these sheep breeds is the Soay, which originally lived on a tiny island called Soay, which actually means “sheep island.” The island of Soay is only about 250 acres in size, or 100 hectares, but that’s not the only place they used to be found. The breed has lived in northern Europe for probably 4,000 years, and was a popular sheep in Britain for centuries. When all the people moved away, 107 sheep living on Soay were moved to Hirta. The sheep on Hirta are feral and receive no care from humans, but they also have basically no predators on the island. They have been studied since 1955 by a small team of scientists and conservationists.

The Soay is a primitive breed of sheep that closely resembles its wild ancestor, the Asiatic mouflon. It’s brown, usually with lighter markings on the face and rump, and the rams often grow a short mane of hair in addition to wool. Rams have dark brown horns and ewes often grow smaller horns too. It also has a short tail. In late spring, Soay sheep shed their fleece naturally instead of needing to be shorn. This is the case with many primitive sheep breeds. Its wool is considered high quality and sought after by handcrafters.

Also like many primitive breeds, the Soay doesn’t have much of a flocking instinct. Soay sheep have been exported from the islands and are kept on farms in many areas for their wool, but if a sheep dog tries to herd a flock of Soay, the poor dog is going to be so frustrated. Soay scatter instead of flocking together. It can also be an aggressive sheep, especially the rams, but it’s also a small breed, with even a big ram rarely heavier than 70 lbs, or 32 kg. And these days, the feral Soay sheep are actually getting smaller overall and have been for the last twenty years. The research team that studies the sheep thinks it’s because climate change has led to shorter, warmer winters, which allows more of the sheep to survive, including smaller sheep that would ordinarily have trouble in cold weather. The smaller sheep breed and their offspring are more likely to be small too, and after twenty years of this the breed overall is smaller than it used to be.

While the Soay used to be a popular breed throughout much of Europe, it’s an at-risk rare breed these days. There are fewer than 1500 breeding ewes registered on farms, in addition to the feral flock on Hirta.

The other breed of St. Kilda sheep is called the Boreray, and it’s also a feral sheep on one of the St. Kilda islands. In this case it lives on the island of Boreray. It’s even rarer than the Soay sheep, the rarest sheep breed in the UK. In 1999 there were only 84 individuals known, but a conservation effort by the Rare Breeds Survival Trust has increased the number to nearly 900 breeding ewes as of 2018.

The Boreray is a little smaller than the Soay and shares characteristics with that breed, including a short tail and its fleece shedding naturally in late spring. It’s usually gray or white, although sometimes brown, often with a speckled black face. Its wool is much coarser than the Soay’s and was traditionally used to make tweed fabric or carpets.

But sheep are domesticated animals, feral or not. What about some of the other animals of St. Kilda?

The St. Kilda wren is a subspecies of Eurasian wren that’s found nowhere else in the world. Like other wrens it’s a tiny songbird, brown and gray with a short tail. It was only recognized as a separate subspecies in 1884, and as happened a lot in those days, museum collectors killed so many of them to stuff and mount that the bird nearly went extinct. Fortunately, early conservationists realized the danger in time, and a special Act of Parliament in 1904 protected the bird. After all the people were evacuated from Hirta, a small team of scientists studied the wren. In 1931 68 nesting pairs were counted, and in 2002 230 breeding pairs were counted. That’s still a low population, but since the wren has almost no predators on St. Kilda, that’s a decent number for such a small habitat.

The St. Kilda wren eats insects, spiders, and other small invertebrates. The male builds the nest out of dead grass and other plants, moss, and seabird feathers.

This is what the St. Kilda wren sounds like:

[St Kilda wren singing]

Another animal found nowhere else in the world is the St. Kilda field mouse, a subspecies of wood mouse. There used to be another mouse subspecies found only on St. Kilda, the St. Kilda house mouse. Both mice were described in 1899, and both are larger than mainland mice. But because the house mouse is dependent on humans, once everyone evacuated the islands the St. Kilda house mouse went extinct within two years.

But the field mouse was fine, and is common throughout the island of Hirta and at least one other island. It actually moved into the abandoned buildings after the house mice went extinct, since houses are full of little nooks and crannies that mice can use as homes. Researchers think the mouse may have been on the islands for something like a thousand years, arriving with Viking settlers.

The St. Kilda field mouse is twice as large and heavy as mainland mice, probably because it basically has no predators. It’s an omnivore like most other mice, and eats seeds, moss, insects and other small animals, and even scavenges meat from dead sheep and birds.

Many sea birds nest on St. Kilda, including Atlantic puffins and northern gannets. The grey seal started breeding on Hirta after everyone left. But except for the sheep, the mice, and the gray seals coming ashore during breeding season, there are no other mammals living on St. Kilda. There are also no trees, no bees, and a limited number of plants and animals, all due to how remote the islands are. They’re 41 miles, or 66 km, away from the Outer Hebrides, a series of much larger islands off the Scottish coast.

Humans have probably lived on Hirta for two thousand years, maybe longer, and have visited the St. Kilda islands as long as 5,000 years ago. But now that the people are gone, the mice and sheep and birds are free to live their quiet lives. As long as they don’t mind a few curious scientists keeping an eye on them.

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

Thanks for listening!

Episode 161: Strange Bird Sounds 2

I still have a cold, so let’s let some birds do part of the talking in this episode about more weird bird calls!

Further reading:

Listen to the Loudest Bird Ever Recorded

Further listening/watching:

A video of the screaming piha. You need to see this.

The yellow-bellied sapsucker is a real bird, and an adorable one too:

The mute swan is not actually mute:

The white bellbird is the loudest bird ever recorded (photo by Anselmo d’Affonseca):

The screaming piha is hilariously loud. Left, sitting like a normal bird. Right, screaming:

Show transcript:

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

I still have this rotten cold, although I’m getting over it. As you can hear, my voice is pretty messed up, so for this episode I’ll let birds do some of the talking for me. Yes, it’s another weird bird calls episode!

We’ll start with this cute little call:

[yellow-bellied sapsucker call]

That’s not a dog’s squeaky toy, it’s a yellow-bellied sapsucker. Yes, that’s a real bird. It’s a type of woodpecker that lives in much of eastern and northern North America, breeding in Canada and spending winters in the eastern United States and Mexico. I get them in my yard sometimes. The sapsucker will also drum on dead trees and other items to make a loud sound to communicate with other sapsuckers.

It mostly eats tree sap, but it also eats berries, small insects, and fruit. To get the tree sap, it drills small holes in tree bark, usually in neat rows, and licks up the sap that oozes from the holes. If you ever see a tree with rows of little holes in the bark, that was done by a sapsucker. It can sometimes even kill trees this way, but for the most part it doesn’t hurt the tree unless the tree is already dying.

Males and females both forage for insects to feed their babies. They usually dip the insects in tree sap before feeding them to the chicks. Yummy!

Next up is this little grunty call:

[mute swan call]

Maybe it’s not exciting or loud, but it’s made by a bird you wouldn’t expect to hear, the mute swan. I mean, the word mute is right there in its name but it’s not mute at all. The mute swan is a big white waterfowl from Eurasia, although it’s been introduced to other parts of the world since it’s so pretty. Its legs are black with an orange and black bill, and it has a long neck that it uses to reach plants that are deeper underwater than ducks and most geese can get at. Its wingspan can be seven and a half feet across, or 2.4 meters. It’s more closely related to the black swan of Australia and the black-necked swan of South America than it is to other swan species from Eurasia.

Mute swans get their name not because they can’t make sounds, obviously, but because they’re not as noisy as other swan species. Not only does it make the little grunting sounds we just heard, it will sometimes hiss aggressively if a person or animal gets too close to its nest. Also, swans can give you such a wallop with their wings that they could knock you out stone cold, so it’s best to just watch them from a distance and not get too close. When mute swans fly, their wings make a distinctive thrumming sound that helps them stay in contact with other mute swans. This is what their wingbeats sound like:

[mute swans flying]

That sounds more like a UFO than a bird, just saying.

Next is a weird metallic call that doesn’t sound like a noise a bird could make either. It sounds like an industrial machine of some kind:

[white bellbird call]

That’s the sound the male white bellbird gives to attract a female. It also happens to be the loudest bird call ever recorded. In late 2018, an ornithologist from Brazil teamed up with a bioacoustician from the United States. They traveled into the mountainous forests of the Brazilian Amazon to record both the white bellbird and our next bird, which I’ll get to in a minute.

The male white bellbird is white with a black bill with a long wattle hanging from it. The female is green streaked with brown. It’s about the size of a pigeon but the male is as loud as a piledriver hammering rock. The male sits on an exposed perch to call, usually the top of a tree. If a female is interested, she’ll join him. The male will turn his back on the female, then turn around quickly to face her during the call, which adds an extra level of drama to an already dramatic call. These birds are the rock stars of the bird world.

The white bellbird eats fruit, some of it rather large, so the bird can open its beak really wide. This makes its beak act as the bell of an instrument like a trumpet, which helps increase the volume of its call. It also has a robust syrinx and unusually strong abdominal muscles. Its call can reach 125 decibels, which is louder than a firetruck’s siren, a rock band, and even a thunderclap.

Let’s finish with another extremely loud bird:

[screaming piha call]

That’s the male screaming piha, which is related to the white bellbird and lives in the same areas in South America. It’s a drab-looking bird, plain grayish in color, and it looks like a type of thrush. It’s a little bit bigger than an American robin. But drab as it is, keep in mind the bird has “screaming” right in its name. It’s almost as loud as the white bellbird.

The screaming piha eats fruit and insects, and it especially likes figs, which it often swallows whole. I like figs too but I chew them. Also, I don’t scream to attract a mate. The male usually perches in a tree and starts with a couple of relatively ordinary-sounding notes. But when he does the actual screaming part, he tips backwards on his perch, pulls his head back into his shoulders, so to speak, opens his beak wide to show how orange it is inside, and SCREAMS. It’s hilarious to watch. I’ve linked to a video in the show notes and you really do owe it to yourself to give it a watch.

The male gives these calls to attract a female, but it’s also useful to define his territory to other males. During mating season the males gather in a group called a lek to show off for females, and then pairs return to the male’s territory to build a nest. We don’t know a whole lot about the bird’s nesting behavior, but they appear to only lay one egg. Fortunately the screaming piha is a common bird that’s doing well, because if you’ve watched that video of one screaming you’ll agree that it’s probably the funniest bird ever and we definitely need them in the world.

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

Thanks for listening!

Episode 159: Sky Animals

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

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

Further reading:

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

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

Further Listening:

unlocked Patreon episode The Birds That Never Land

Rüppell’s vulture:

The bar-headed goose:

The common crane:

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

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

“Or does it flatly overlie this earth…?

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for listening!


Episode 155: Extreme Sexual Dimorphism

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

The elephant seal male and female are very different sizes:

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

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

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

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

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

Lamprologus callipterus males are much larger than females:

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

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

You can find Strange Animals Podcast online at That’s blueberry without any E’s. If you like the podcast and want to help us out, leave a rating and review on Apple Podcasts or whatever platform you listen on. If you have questions, comments, or suggestions for future episodes, email us at We also have a Patreon if you’d like to support us and get twice-monthly bonus episodes.

Thanks for listening!

Episode 146: Three strange animals

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

An archerfish, pew pew pew:

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

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

A white-winged nightjar showing off his wings:

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[chuck will’s widow song]

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

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

[white-winged nightjar wings beating]

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

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

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

Thanks for listening!

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

[little nightjar calls]

Episode 144: Strange Bird Sounds

This week we’re going to learn not about strange birds, but about strange sounds some birds make. Thanks to Sam for the suggestion, and thanks to Llewelly and Leo for suggesting two of the birds we feature today!

Further watching:

Greater prairie chicken courtship display

A bittern, weird swamp bird:

An American woodcock, adorable:

Ocellated turkey, beautiful and goofy:

Greater prairie chicken:

Show transcript:

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

Halloween is over and we’re all just about sick of candy, or maybe that’s just me. Either way, if you live in the northern hemisphere we’re heading into winter, but if you live in the southern hemisphere spring is in full swing! And spring means birdsong! Thanks to Sam for the suggestion that we do a whole episode about interesting bird calls, and thanks to Llewelly and Leo for some excellent bird suggestions.

But we can’t cover all the weird bird calls out there in one episode. I think I’ll make this a recurring topic, and every so often we’ll get a weird birdsong episode. This time we’ll learn about a few birds of North America, although one is from Central America. Let’s start with this unusual sound.

[Bittern call]

That’s the call of the male American bittern, a type of heron that lives throughout most of North America. It’s brown with paler streaks that help camouflage it in the reeds and water grasses where it spends most of its time. It likes freshwater marshes and other wetlands with lots of tall plants to hide in. When the bittern feels threatened, it stands still, points its long bill upwards with its neck stretched out, and sways slightly to imitate the reeds around it. But it still does this even if it’s standing out in the open, because while it’s a neat bird, it maybe is not exactly a genius.

The bittern eats fish, crustaceans, insects, and other small animals. Like many birds, whatever parts of its food it can’t digest, like fish scales and dragonfly wings, form into pellets in its digestive tract that it regurgitates later. Males sometimes fight over territories by flying upwards in a spiral, both birds trying to stab each other with their bills.

The male is the one that makes the weird call we just heard. He gulps air to inflate his esophagus, which is the inside part of the throat, and uses the air to make his call. This is more similar to the way frogs call than birds. He also clacks his bill. He only makes this call during breeding season, which is in the spring and summer.

Next, let’s listen to the call of another North American bird, the American woodcock:

[American woodcock sound]

The American woodcock is a relatively small bird with short legs, basically no tail, large black eyes, and a long pointy bill. It’s considered a game bird although I’m not sure why, since people don’t seem to eat it. It’s brown with black and lighter brown markings which camouflage it perfectly among dead leaves, and it looks like a shore bird because it’s actually closely related to shore birds like sandpipers. It lives in woodlands and pastures throughout eastern North America. It uses its long bill to probe the ground for earthworms, and the tip of the upper half of the bill, properly called a mandible, is flexible so the woodcock can grab a worm without actually opening its beak. It also eats small insects and other invertebrates, and seeds. It’s mostly active at dawn and dusk, and it migrates at night.

In spring, the male woodcock attracts females by a flight display called sky dancing. He spirals upward, then down again, chirping melodically while the wind through three specialized primary feathers in his wings make a twittering sound, which is what we just heard.

Next is this bird, which was suggested by Llewelly.

[ocellated turkey call]

That’s the ocellated turkey, also called the green peacock. It mostly only lives in a small area of Mexico called the Yucatan Peninsula. It’s a type of wild turkey and at first glance it looks and acts like an ordinary turkey. But when the male fans his tail as a display to females, the tail feathers have colorful eyespot patterns like a peacock’s tail.

The ocellated turkey has a bluish head bare of feathers, with a red wattle on its face. Its body feathers are black, copper, green, and white, which makes it even prettier than an ordinary turkey. I know people think turkeys are ugly, but wild ones are actually quite attractive birds. Both males and females have eyespots on the tail feathers.

The ocellated turkey is smaller than the wild turkey, which it’s related to. It’s also related to chickens, pheasants, partridges, and peacocks, more properly called peafowl. Like most of these other birds, it can fly but prefers to walk or run on its sturdy legs.

It eats seeds and other plant parts, insects, and other small animals. Most of the year, males form small bachelor flocks while females form larger flocks together with their half-grown babies. In breeding season, though, males will fight each other, although mostly they just want to impress hen turkeys with their elaborate display dances and gobbling calls, which we just heard.

The ocellated turkey is related to another bird with an interesting call, this one from the Midwestern area of North America, the greater prairie chicken. Thanks to Leo who suggested this one ages ago! This is what the greater prairie chicken sounds like:

[greater prairie chicken calls]

It’s about the size of an actual chicken with a short tail, rounded wings, and mostly brown and black feathers. The male has big round patches on either side of the neck that are bare of feathers. The skin on this patch is a yellowy-orange, as is the male’s comb. During mating season, the male inflates the neck patch to show off for females and performs a display dance.

The display takes place in groups where both males and females come together on what are called booming grounds. A male inflates his neck pouches, raises his tail to show a white patch of feathers, raises long black feathers on his neck to look like horns, and lowers his head. Then he stamps the ground, leaps in the air, makes cackling and loud cooing sounds, rushes at other males, and basically tries to impress as many females as he can. It’s actually really funny to watch. I’ll try to find a good video of it and link to it from the show notes.

There used to be a subspecies of greater prairie chicken called the heath hen that lived in the eastern United States, but it went extinct in 1932 from overhunting. It actually pretty much went extinct by 1870, maybe as early as 1840, with only a small population remaining on the island of Martha’s Vineyard. The Martha’s Vineyard birds were protected in 1908 and started to rebound from only 70 birds to nearly 2,000, but a combination of inbreeding, poultry disease, a fire that destroyed most of the nests in 1916, and several unusually severe winters sent the population plummeting again. In 1927, only 13 birds remained, and 11 of them were males. The next year only males remained, and by 1932 the very last male was seen all alone on the booming grounds. He died soon afterwards, and that was the end of the heath hen.

Modern conservationists have considered introducing greater prairie chickens to Martha’s Vineyard, since the heath hen was important to the local ecosystem. There’s even been speculation that the heath hen might be a good candidate for de-extinction, with genetic material collected from museum specimens and edited into the closely related greater prairie chicken genome.

We’ll finish up with a chirping song that some of you may recognize. See if you can figure it out.


Did you get that one? It was a trick question, because that’s not a bird! It’s a CHEETAH! And now you have a hint about what next week’s episode is about.

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

Thanks for listening!

Episode 139: Skunks and Other Stinkers

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 That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 138: City Animals

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 That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at We also have a Patreon if you’d like to support us that way.

Thanks for listening!

Episode 136: Smallest of the Small

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 That’s blueberry without any E’s. If you have questions, comments, or suggestions for future episodes, email us at We also have a Patreon if you’d like to support us that way.

Thanks for listening!