Tag Archives: mice

Episode 294: Updates 5 and a New Zealand Parrot!



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

Further reading:

Vitiligo

Tyrannosaurus remains hint at three possible distinct species

Study refutes claim that T. rex was three separate species

The reign of the dinosaurs ended in spring

Impact crater may be dinosaur killer’s baby cousin

California mice eat monarch butterflies

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

Playground aims to distract mischievous kea

The kea showing off the bright colors under its wings:

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

Show transcript:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

This is what the play call sounds like:

[kea call]

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

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

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

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

Thanks for listening!


Episode 268: Rediscovered Animals!



My little cat Gracie got lost but she’s home! Let’s learn about some other rediscovered animals this week!

A very happy birthday to Seamus! I hope you have the best birthday ever!

Further listening:

The Casual Birder Podcast (where you can hear me talk about birding in Belize!)

Further reading:

Bornean Rajah Scops Owl Rediscovered After 125 Years

Shock find brings extinct mouse back from the dead

Rediscovery of the ‘extinct’ Pinatubo volcano mouse

Gracie, home at last! She’s so SKINNY after a whole week being lost but she’s eating lots now:

The Bornean Rajah scops owl (photo from article linked above):

The djoongari is the same as the supposedly extinct Gould’s mouse (photo from article linked above):

The Pinatubo volcano mouse:

Show transcript:

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

While I was researching animals discovered in 2021, I came across some rediscoveries. I thought that would make a fun episode, so here are three animals that were thought to be extinct but were found again!

A couple of quick things before we get started, though.

First, happy birthday to Seamus! I hope you have a brilliant birthday and that it involves family, friends, or at least your favorite kind of cake, but hopefully all three.

Next, a few weeks ago I appeared on the Casual Birder Podcast talking in depth about my trip to Belize and some of the birds I saw there. I’ll put a link in the show notes. It’s a great podcast that I really recommend if you’re interested in birding at all, and the host has such a lovely calming voice I also recommend it if you just like to have a pleasant voice in the background while you do other stuff.

Finally, thanks for the well wishes from last week, when I let our emergency episode run. I’m actually fine, but my little cat Gracie got frightened while I was bringing her into the house from a vet visit, and she ran away. That was on Friday, March 11 and I spent all night looking for her, but then we had a late-season snowstorm come through and dump six inches of snow on my town, which made me even more frantic. At dawn on Saturday I put on my boots and heavy coat and spent all day searching for Gracie, and on Sunday I was still searching for her. I didn’t have time to work on a new episode. In fact, I searched every day as much as possible all week long, until I was certain she was gone forever. I couldn’t bring myself to work on this episode because rediscovered animals just seemed like a cruel joke when my little cat was gone. I was almost done with a different episode when on Saturday night, March 19, 2022, eight full days after Gracie had disappeared, I got a phone call. Someone had seen a little gray cat under their shed, over half a mile from my house! I rushed over and THERE WAS GRACIE! I found her! She is home!

So I’ve been researching rediscovered animals with Gracie purring in my lap, in between her going to her bowl to eat. She’s lost a lot of weight but other than that she seems healthy, and she’s very happy to be home.

The person who found Gracie first noticed her around their birdfeeder, so we’ll start with a rediscovered bird.

There are two subspecies of Rajah scops owl that are only found on two islands in southeast Asia, Borneo and Sumatra. The subspecies that lives in Sumatra is fairly common throughout the mountains on that island, where it lives in the lower branches of trees in higher elevations. It’s a tiny owl that only weighs about 4 ounces, or 100 grams. As the article I link to in the show notes points out, that’s about the weight of four AA batteries.

The subspecies that lives on Borneo, though, was always much rarer and had a much smaller range. In fact, no one had seen one since 1892 and researchers thought it was probably extinct. There’s another owl that lives in the mountains of Borneo, the mountain scops owl, that’s fairly common.

In May of 2016, a team of scientists started a 10-year study of birds that lived on Mount Kinabalu in the country of Malaysia in northern Borneo. One team member, Keegan Tranquillo, was checking bird nests that very same month and noticed an owl that didn’t look like the mountain scops owl. It was larger and its plumage was different.

Tranquillo contacted ecologist and bird expert Andy Boyce, who came out to take a look. When he saw the owl, Boyce was excited at first but then filled with anxiety. He knew the owl must be incredibly rare and would be in great danger of going extinct if conservation efforts weren’t put into place. Many areas of Borneo are under pressure from logging, mining, and palm oil plantations, which is leading to habitat loss all over the island.

Not only that, the more Boyce looked at the owl, the more he noticed differences from the Sumatran subspecies of Rajah scops owl. He suspected it might not be a subspecies but a completely separate species. That made it even more important to protect the owl and study it.

The owl’s rediscovery was announced in May 2021. Studies of the owl are ongoing but hopefully will soon result in more information about it and its habitat.

Next, let’s talk about a rodent, since Gracie likes to play with toy mice. This rediscovery came from Australia, where a study of extinct Australian rodents and their living relations found something surprising. It’s the opposite of the owl we just talked about, that might end up being a separate species of its own.

The mouse in question was once called Gould’s mouse. It used to be common throughout Australia, where it’s a native mammal, but it was declared extinct in 1990 after no one had seen it since the 1840s. Researchers suspected it had gone extinct after colonizers brought cats to Australia, although diseases and competition from introduced species of mice and rats also had a big impact.

Meanwhile, another native mouse, called the djoongari or Shark Bay mouse, was driven nearly to extinction. Fortunately, the djoongari survived on a few islands off western Australia. Conservation efforts in 2003 introduced it to more islands, where it spread and did well. It’s a social mouse that lives in family groups in a burrow it digs under bushes. It lines the burrow with dry grass to make it warmer and more comfortable.

The djoongari is a large mouse, up to 4.5 inches long not counting the tail, or 11.5 centimeters. The tail is a little longer than the head and body combined. It has long, shaggy fur that’s a mixture of dark and light brown with a paler belly and feet, and it has a tuft of dark fur at the end of its tail like a tiny lion.

In early 2021, the researchers studying native rodent DNA realized that the living djoongari and the extinct Gould’s mouse had the exact same genetic profile! They were the same animal! That means Gould’s mouse didn’t go extinct, although technically it didn’t exist in the first place.

That doesn’t mean the djoongari is perfectly safe, of course. Its range is still extremely restricted and it’s vulnerable to the same factors that nearly drove it to extinction in the first place. But at least it’s still around and can be protected.

We’ll finish with another mouse. In 1991, a volcano in the Philippines erupted. The volcano was called Mount Pinatubo on the island of Luzon, and the eruption was enormous. It was ten times stronger than the eruption of Mount St. Helens in 1980. Lava and ash filled valleys up to 600 feet deep, or 183 meters. More than 800 people died from the eruption itself and the devastation afterwards, during landslides caused by all the ash every time it rained.

In addition to the awful situation for people, animals were affected too. Most of the forests near the volcano were completely destroyed. Scientists thought the Pinatubo volcano mouse had probably gone extinct since it only lived on that one volcanic mountain, which had just blown up. Surveys of the area a few years after the eruption didn’t turn up signs of any of the mice.

The Pinatubo volcano mouse was only described in 1962 from a single specimen collected in 1956. It was a large mouse, almost the size of a rat, with long hind legs for jumping and climbing and a tail much longer than the length of its head and body together. It mostly ate earthworms and other small animals, but not a lot was known about it.

More than 20 years after the eruption, a team of scientists surveyed the animals living on the mountain. The conditions were difficult for the team to navigate, since there was still a lot of ash and erosion in the area that made the steep slopes unstable. The lush forests were gone, replaced by grass and bamboo, shrubs, a few trees, and other plants. They didn’t expect to find a lot of animals, although they thought they’d find introduced species of rats and mice that had moved into the disturbed areas from other parts of the island.

But to their surprise, they found 17 species of mammal on the mountain. Eight were bats, there were wild pigs and deer, and the rest were rodents. And the rodents were mostly native species, not introduced ones—including the Pinatubo volcano mouse!

Researchers theorize that a mouse that lives on an active volcano as its only habitat must have evolved to weather occasional eruptions. The mice were actually most numerous in the places that had been the most destroyed. The term for a species that thrives in environments that have seen widespread natural destruction is “disturbance specialist,” and that’s just what these mice are.

It just goes to show that no matter how bad things may be, there is life. And where there’s life, there’s hope. And probably mice.

Now, if you will excuse me, I have to go make a chocolate cake to take to the person who found Gracie.

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

Thanks for listening!


Episode 251: Modern Mimics and HIREC



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This week let’s look at some animals that have evolved rapidly to adapt to human-caused environmental pressures. Thanks to Otto and Pranav for their suggestions!

Further reading:

Long-term changes of plumage between urban and rural populations of white-crowned sparrows (Zonotrichia leucophrys)

A light-colored peppered moth (left) and darker-colored peppered moths (right):

Soot is hard to clean off buildings and other items (image from this page):

A white-crowned sparrow in the California countryside:

A (deceased museum specimen being photographed) white-crowned sparrow from the city of San Francisco, CA (taken from the study linked above):

A decorator crab that has attached bits of plastic and other trash to its body (image from this page):

The hermit crab sometimes uses trash instead of shells to hide in:

Show transcript:

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

This week we have two listener suggestions. Otto suggested we learn about camouflage that mimics modern things, and Pranav suggested animals that show rapid evolution due to humans.

We’ve talked about animals that use camouflage in lots of episodes, especially episode 191, Masters of Disguise. If you want to learn more about camouflage itself, that’s a good one to listen to. In addition, rapid evolution due to humans is a hot area of research right now. It even has its own scientific term, human-induced rapid evolutionary change, often shortened to the acronym HIREC.

Let’s start this episode with the story of a humble moth, because it’s a classic example of both HIREC and modern camouflage.

The peppered moth lives throughout much of the northern hemisphere. Its wingspan is a little over 2 inches across, or about 6 centimeters, and its caterpillar looks just like a little twig. Not only that, the caterpillar can change its coloring to match the twigs of the tree it’s on. But it’s not the caterpillars we’re talking about today.

The peppered moth gets its name from the coloring of its wings, which are white with black speckles, like pepper spilled on a plate. The pattern of speckles is unique to each individual, with some moths having more pepper speckles than others. Some moths have so many speckles that they look gray. But in the 19th century, geneticists studying moths in England noticed that the peppered moth seemed to be changing color as a species. Specifically, some of the peppered moths were completely black.

Black peppered moths had never been documented before 1811. They were still rare in the mid-19th century, but by 1900 almost all of the peppered moths in cities in England were black. Scientists noticed this and tried to figure out what was going on.

Pollution is what was going on. The industrial revolution was in full swing, but all those factories and trains and even ordinary houses were burning coal. Burning coal results in soot that’s carried on smoke and settles on everything. If you have a coal fire in your house, your walls and furniture are going to end up dark with soot. My aunt and uncle renovated a house from the late 19th century and had a lot of trouble cleaning soot from the walls and woodwork, even the old curtains that had been in the house. Similarly, when I lived briefly near Pittsburgh, Pennsylvania, there were still a lot of brick and stone buildings that were black from soot, but one beautiful old church had recently been cleaned and it turned out that the stone it was built from was pale gray, not black.

It wasn’t coal soot getting on the moths, though. It was coal soot on the trees where the moths spent most of their time. Most tree trunks are gray, but with all that coal soot in the air, the trees were coated with it and were much darker gray or even black. A light-colored moth that settled on a black tree branch showed up to predators, but a black moth on the same branch was camouflaged. The black moths survived more often to lay eggs while the white or gray moths didn’t, passing on the genetic likelihood that their babies would grow up to be dark-colored instead of light-colored.

It wasn’t just peppered moths that this happened to, either. More than 100 species of moth were documented to be dark gray or black during this time when they were ordinarily much lighter in color. Scientists call this industrial melanism.

Soot is made up of tiny particles that work their way into the crevices of wood and stone and everything else they come in contact with. You can’t just wipe or rinse it off. It’s acidic too and will kill plants, especially lichens that grow on trees, and it even eats away at stone and brick. It’s dangerous to breathe because the tiny particles lodge in your lungs and eventually stop you from being able to absorb oxygen as efficiently. If you’ve heard of the infamous London smog from the olden days, a big contributor to the smog was coal smoke. In 1952 a five-day smog event in London killed an estimated 12,000 people. That led directly to the Clean Air Act of 1956, and these days London doesn’t have that kind of deadly smog anymore.

Once factories and homes switched to electricity, natural gas, or other alternatives to burning coal, and trains switched to diesel fuel, trees stopped being coated with soot. Older trees that had survived were still dark, but young ones grew up with normal colored trunks and branches. Gradually, the black moths became less and less numerous compared to light-colored moths.

Cities in general result in rapid evolution of animals, including how they camouflage themselves. A study published in May of 2021 found that some birds living in cities are developing different colored feathers. Specifically, white-crowned sparrows living in San Francisco, California have much duller, darker feathers on their backs than white-crowned sparrows living outside of the city. Other studies have found that birds in cities sing much louder and at a higher pitch than birds in the countryside, since they have to compete with traffic and other noise.

A Swiss study on the effects of light on ermine moths indicated that while moths who developed from caterpillars collected from the countryside showed a normal attraction to light, moths from caterpillars collected in the city ignored the light. Since moths often die when they collide with electric lights, the city moths who survived to lay eggs were the ones who didn’t fly into a hot lightbulb.

Another study compared the genomes of white-footed mice that live in various parks in New York City with white-footed mice that live in state parks well outside of the city. The mice in city parks showed a lot less genetic diversity, naturally, since those mice are isolated populations. Mice can’t take cabs to visit mice in other parks, much less leave the city for a vacation. But the city mice showed another surprising difference. Their digestive systems have adapted to a much different diet than their country cousins. Some researchers suggest that the city mice may eat more junk food, which people throw away and the mice find, while other researchers think it’s just a difference in the kinds of insects and plants available in city parks for the mice to eat. Either way, it’s a distinct genetic difference that shows how the city mice are evolving to adapt to their urban environments.

Another example is a type of reptile called the crested anole. It’s related to the iguana and is native to the Americas. There are lots of species and subspecies of anole, many of which live on islands and show distinct adaptations to various habitats. The crested anole lives in Puerto Rico and on some nearby islands and grows up to 3 inches long, or 7.5 cm, not counting its long tail. The male is more brightly colored than the female, usually green or brown with darker spots. It’s not related to the chameleon but it is able to change color. It eats small animals, including insects, worms, even other anoles. Anoles are really interesting animals that deserve their own episode one day, so let’s just talk about how the crested anole that lives in cities has adapted to urban life.

One thing the crested anole is known for is its ability to climb right up tree trunks and even perch head-down in a tree. Its toe pads have microscopic scales and hairs that help them adhere to smooth surfaces, something like a gecko’s toes. But there’s a big difference in a tree trunk, no matter how smooth it is, and a pane of glass. Anoles in cities can climb up and down windows and painted walls. Researchers examined the toe pads of city crested anoles and compared them to the toe pads of crested anoles who lived in the countryside. They found that the city anoles had larger toes with more scales, and they even had longer legs. The research team also raced anoles along various surfaces and filmed them in slow motion to study how they were able to maneuver, which sounds like a great day at work.

The crested anoles have only lived in cities for a few decades, so their differences from country anoles evolved very quickly. But not all species of anole can adapt as well and as rapidly as the crested anoles have. Other city anole species don’t show differences from their country cousins.

Human-induced rapid evolutionary change isn’t restricted to cities. Trophy hunters who target the biggest animals with the biggest horns or antlers and leave smaller individuals alone have resulted in only smaller males with smaller horns or antlers surviving to breed. Many populations of bighorn sheep now actually only have small horns. Similarly, elephants have been killed for their tusks for long enough that many elephants are being born without tusks, because tuskless elephants are the ones that survive to breed. Entire populations of some fish species are smaller overall after many generations of being caught with nets, because only the individuals who are small enough to escape the nets survive to breed.

I tried hard to find more examples of animals that camouflage themselves to blend in to human-made items like roads. I’m sure this is happening throughout much of the world, but I couldn’t find any scientific studies about it. If any of you are thinking of going into biology, that might be an interesting field of study. But I did find one other example.

Self-decoration is a type of camouflage I don’t think we’ve talked about before. It’s where an animal decorates its body with items that help it blend in with its surroundings. Some caterpillars will stick little bits of lichen or other plant pieces to their bodies to help them hide, and some invertebrates of various kinds actually pile their own poop on their back as a disguise.

A group of crabs called decorator crabs will stick plants, sponges, and other items to their backs, and different species have preferences as to what items they use. Some species prefer stinging or toxic decorations, such as certain sea anemones which they basically pick up and plant on their backs. Researchers think the sea anemones actually benefit from being used as camouflage, because crabs are messy eaters and the anemones can catch and eat pieces of food that float away from the crab’s mouthparts. A decorator crab’s carapace is often rough in texture with tiny hooks to help things stick to it like Velcro.

Some decorator crabs don’t seek out particular decorations but just make use of whatever small items they find in their local environment. In the past few decades, scientists, divers, and other people who find crabs interesting have noticed more and more decorator crabs using little pieces of trash as decoration. This includes fragments of plastic and pieces of fishing nets.

This is similar to what’s happening with hermit crabs, which we talked about in episode 182. In many places hermit crabs are using trash like bottle caps instead of shells since there’s so much trash on beaches these days. This is your reminder to pick up any trash you find on the beach, but be careful not to cut yourself and also make sure you’re picking up actual trash and not a camouflaged crab.

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

Thanks for listening!


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

Thanks for listening!


Episode 054: Regenerating Animals



This week we’re going to learn about animals that can regenerate parts of their body. What animals can do it, how does it work, and can humans figure out how to make it work for us too?

Thanks to Maxwell of the awesome Relic: The Lost Treasure podcast for suggesting this week’s topic!

The planarian, not exciting to look at but you can get a lot of them easily:

A starfish leg growing a new starfish, or possibly a slightly gross magic wand. Ping! You’ve been turned into a magical starfish:

The adorable axolotl:

The almost as adorable African spiny mouse:

A hydra. Not really very adorable except possibly to other hydras but kind of pretty:

Show transcript:

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

This week’s episode was going to be about lungfish, but I had to postpone it because I ran across some conflicting information about a mystery lungfish, which required me to order a book that probably won’t arrive for a week or two. So when I tweeted about needing a new topic quick, Maxwell of the Relic: The Lost Treasure podcast suggested animals that can regenerate parts of their bodies.

We’ve touched on regenerative abilities before in one or two episodes. Some lizards can drop their tail if threatened, which then regrows later—but a lizard can only do that once. The fish-scaled gecko from episode 20 can lose its scales and regenerate them repeatedly. But other animals can regenerate not just bits and pieces, but entire organs and even their brains. The sea lamprey can even regenerate spinal cord cells. You better believe researchers are trying to figure out how regeneration works and if it can be adapted for human application.

A lot of worms can regenerate lost pieces, including earthworms. Whenever I’m gardening and accidentally cut an earthworm in half with the shovel, I reassure myself that the worm will regenerate the end I cut off. Some species can even grow back from both cut pieces, effectively turning one earthworm into two, depending on where it is severed, although that’s rare. Some species of worm can only regrow the tail, but some can regrow the head. And some, of course, can’t regrow anything. Leeches are a type of worm but they can’t regenerate at all.

Planarians are flatworms. Some species live in water, some in damp areas on land, but they can all regenerate. If you cut a planarian in two, each half will regenerate into a new planarian. If you cut a planarian in three, you’ll get three planarians. Cut one into four, you get four planarians, and so on and on. Researchers with a lot of time and patience have determined that you can cut a planarian into as many as 277 pieces and you will get 277 planarians after a few weeks. But I guess if you cut a planarian into 278 or more pieces, some of the extra pieces won’t do anything.

Starfish are well-known to regenerate lost or injured legs, and may even drop a leg to escape from predators the way some lizards drop their tails. Some species of starfish can regrow an entire starfish from a single limb. That’s oddly creepy. I don’t know why I find it so creepy. I don’t find the planarians creepy. It’s like if I was run over by a motorboat that chopped my arms and legs off, and instead of dying I not only regrew my arms and legs, my severed arms and legs each grew a new me. I don’t think I’d like that. Although I’m not going to get in the water so I doubt I’ll be run over by a motorboat, and also if I was, sharks would probably eat me before we could see if any parts regrew.

Many starfish relations, such as sea urchins and sea cucumbers, can also regenerate body parts. When the sea cucumber is threatened, it can and will eject its internal organs. They’re sticky and full of toxins, which deters predators, and the sea cucumber just regenerates them.

Most crustaceans, such as crabs and krill, can regenerate legs. So can spiders, which may drop legs to escape from predators. That’s called autotomy, by the way, when an animal detaches a body part to escape from a predator. Spiders molt their exoskeletons every so often as they grow, and lost limbs grow back after molting. Sometimes it takes a few molts for the leg to be the same size as the other legs. Spiders can also regenerate other lost or damaged parts, including mouthparts and spinnerets.

Salamanders and newts can regenerate limbs, tail, some organs, jaws, even parts of their eyes. Frogs and other amphibians can’t. Likewise, some fish can regenerate injured tissue, such as the zebrafish which can regrow fins and eye retinas, and some species of sharks that can regenerate skin tissue, while others can’t. The axolotl, which is an adorable rare salamander found in Mexico, can regrow just about any part of its body, including its spinal cord and up to half of its brain.

So what about mammals? Do any mammals have regenerative capabilities? As a matter of fact, yes. The African spiny mouse is the big regenerator among mammals. It’s actually more closely related to gerbils, and it has stiff guard hairs all over its body that stick out and make it look fuzzy but which act as spines to help ward off predators. But if a predator attacks anyway, three species of the spiny mouse can autotomically drop off part of its skin, which later grows back. Some species of spiny mouse are kept as pets, even though they don’t do very well in captivity. The pet species don’t have regeneration abilities, incidentally. However, they do have delicate tails that are easily injured, which they then lose, and the tail does not grow back.

Those three species of African spiny mouse can also regenerate ear tissue. If a spiny mouse’s ear is damaged, even if it has a hole as big as four mm across, it can regenerate the ear as good as new rather than heal it with scar tissue. A number of mammals can regenerate small injuries to ear cartilage under the right circumstances, including cats. Rabbits can also regrow damaged ear tissue, and have some other regenerative abilities too.

It’s all well and good to point out that a whole lot of animals can regenerate lost or damaged body parts. But how does it work? And more to the point, why can’t humans do it?

Technically, humans and other animals are regenerating certain cells all the time, especially skin cells and blood cells. Small cuts and scrapes heal up without scarring and we don’t think about it at all. Fingertips will grow back after injury and the liver can regenerate. The endometrium, which is the lining of the uterus, is partially reabsorbed into the body and partially expelled from the body every month during menstruation, then regrows. Toenails and fingernails regrow after injury. We just don’t think about all these things because they seem normal to us, whereas we can’t regrow a whole finger if it’s been chopped off, for instance.

I won’t go too deeply into how regeneration works, mostly because it’s complicated and I don’t want to screw it up too badly. There are also different types of regenerative abilities with different processes. Basically, though, as an example, when a salamander loses a leg, the cells surrounding the wound dedifferentiate, basically turning from regular skin cells or what have you into stem cells that can grow into anything the body needs. These cells form what’s called a blastema, which is just the fancy name for a bundle of dedifferentiated cells. Then the blastemal cells start differentiating again, this time into the cells needed to regrow the leg, just as stem cells grew legs when the salamander was developing in its egg.

It sounds pretty simple, put like that. I mean, that’s how we all develop in the first place, from a fertilized egg into a person who can make podcasts and eat cupcakes. The main problem is figuring out how to get human cells to dedifferentiate into a blastema. Because it’s not just injuries that could be helped if scientists figure this out, it’s all sorts of problems. People who have lost their sight due to retinal diseases could regrow new retinas. People born with birth defects could have the nonstandard parts regrown so that they work the way they’re supposed to.

Researchers are working hard to figure all this out. Stem cell research is a big part of regenerative research. Unfortunately, at some point the rumor started that all stem cells come from babies, specifically embryonic stem cells. When a human egg is fertilized, after a couple of days a blastocyst is formed from the cells, which is similar to a blastema but made of cells that have never differentiated into anything else. They’re brand new cells with the capacity to make a brand new human. Naturally, people are squiffy about taking cells that might make a baby and using them for something else. But amniotic fluid, the fluid that surrounds the baby as it’s growing in its mother, also contains stem cells, and they can be harvested without hurting the baby or the mother. You can also get stem cells from the umbilical cord right after a baby is born, and the umbilical cord is just cut off and thrown away anyway so you might as well give it a little extra use. But most stem cells used in research and treatment these days come from bone marrow, lipid cells in fat tissue, and blood, all of which can be extracted without harming the person. They’re not as powerful as embryonic and amniotic stem cells, but they have the benefit of being from the patient’s own body, so no immunosuppression is required to make sure the body accepts them in stem cell treatment.

That was a lot of confusing medical information, so let’s talk about one more animal that can regenerate, the hydra. We’ve talked about the hydra before in the jellyfish episode, which for a long time was our most popular episode. It’s now our second-most downloaded episode, with our first episode inexplicably in the top spot. The hydra is a freshwater animal related to jellies that can regenerate so completely it’s essentially immortal.

The hydra is related to the so-called immortal jellyfish we talked about in episode 19. It can regenerate just about any injury, and like the planarian it can regenerate into more than one copy of itself if it’s cut up into tiny pieces. It’s only a few millimeters long but its tiny body is full of stem cells, and as long as stem cells are present in the body part that was cut off, an entirely new hydra can grow from it. Because of its amazing regenerative abilities, some admittedly controversial studies suggest the hydra doesn’t age. That’s a neat trick, if you can manage it.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on Apple Podcasts or whatever platform you listen on. We also have a Patreon if you’d like to support us that way.

Thanks for listening!


Episode 039: The Devil’s Footprints



Happy Halloween, everyone! This week’s episode is about a spooky occurrence in 1855, where people in Devon woke to find small hoofprints all over the place, even on roofs. Join us in an attempt to figure out just what animal might have made the devil’s footprints!

The footprints as drawn by the Rev. Ellacombe from newspaper accounts:

The h*ckin adorable wood mouse:

Link to lots of pictures of jumping wood mice omg

Wood mouse prints from jumping, from Leutscher via Dash (see further reading, below):

Mystery print from 2009:

Further reading:

The Devil’s Hoofmarks: Source Material on the Great Devon Mystery of 1855 edited by Mike Dash

HALLOWEEN BONUS AW YISS! I’ve unlocked the following Patreon bonus episodes so everyone can listen. You should be able to open them in your browser without needing a Patreon login:

Animals That Glow

The Beast of Busco

Weird Teeth

Carnivorous Plants

Also thank you for buying a lot of copies of my book Skytown:

Amazon USA

Amazon UK

Show transcript:

Welcome to Strange Animals Podcast Halloween episode for 2017. I’m your host, Kate Shaw. This is the best time of the year if you like candy, ghost stories, monsters, wearing spooky costumes, and buying all the bat decorations in Target. I have so many bat decorations. I’ve stopped taking them down after Halloween and my room looks like a bat cave.

Before we get started, a quick heads-up that I’ve unlocked a few of the older Patreon bonus episodes so that anyone can listen to them. They won’t show up in your feed but I have links to the specific episodes in this week’s show notes so you can go listen to them in your browser if you’re interested. You don’t even need a Patreon login. I hope you enjoy them as an extra Halloween treat.

Another reminder that I have a novel available through Fox Spirit Books. It’s called Skytown and it’s a fun steampunk adventure story. I’ll put a link in the shownotes if you want to learn more.

Oh, and if you want a Strange Animals Podcast sticker, just send me your mailing address at strangeanimalspodcast@gmail.com and I’ll mail you one!

Now, on with the spooky Halloween episode!

This week’s episode is something that has baffled me since I read about it as a kid. It’s baffled everyone for more than 150 years. I’ll tell you now that while I make one suggestion that seems plausible to me, it’s by no means a perfect match for the creature that made…the devil’s footprints.

/reverb reverb reverb

The winter of 1855 was especially bitter in England. Around Devon, the rivers froze solid and temperatures stayed below freezing almost every day and night from January to March. On the night of February 8 it snowed, but towards dawn a brief thaw turned the falling snow to rain before the temperature dropped again and a frost fell. When residents of Devon woke on the morning of February 9, they found some 4” of snow on the ground, or 10 cm. They also found small hoofprints everywhere.

These weren’t ordinary hoofprints. A donkey or pony hadn’t gotten loose during the night and wandered around. Some of the prints did look like a donkey’s, but some appeared cloven, more like a large goat’s hoof. And the stride was short, only about 8” between most prints, or a little over 20 cm, sometimes about double that. Besides, the prints appeared in places where a donkey couldn’t possibly have left prints: on rooftops, inside gardens with tall walls and locked gates. Even a nimble goat couldn’t have managed that without someone hearing a goat bounding around. Sometimes a line of prints would walk right up to an obstacle, like a haystack or hedge, and continue on the other side as though the obstacle didn’t exist. Tracks began or ended abruptly as though the animal had dropped from or flown into the sky.

And there were untold thousands of the prints. Some villages had prints in almost every yard. They appeared in churchyards among gravestones, in gardens and on doorsteps, in fields and roads. They meandered from place to place or sometimes continued in a straight line. And they appeared to be made not by a four-footed animal but by something walking on its hind legs, placing one hoof nearly in front of the other.

People tracked some of the prints for miles without coming across any clue as to what had made them. A few forward thinkers made sketches of the prints and jotted down notes. By February 13, reports of the strange footprints had made it into the local newspapers.

Beyond the often maddeningly vague newspaper accounts, most of what we know about the hoofprints comes from the Reverend H.T. Ellacombe, who was vicar of the parish of Clyst St George from 1850 to 1885. He collected letters and sketches and made his own notes about the event, since some of the prints appeared in his own rectory grounds. Local historian Major Antony Gibbs discovered Ellacombe’s bundle of notes and letters in 1952, tucked away in a church office gathering dust.

But a series of letters published in 1855 by the Illustrated London News has been more influential than Ellacombe’s information. The letters were written by someone who signed himself “South Devon,” and we know from Ellacombe that South Devon was a 19-year-old local man whom Ellacombe called “young D’Urban.”

William D’Urban’s letters were exciting, to say the least. If you’ve heard anything about the devil’s footprints before, it was probably mostly details from D’Urban’s account. According to him, all the prints were identical in size, the stride likewise did not vary, and the prints were one unbroken trail at least 40 miles and as much as 100 miles in length, or 64 to 160 kilometers. This has sometimes been garbled in later retellings as a perfectly straight trail 100 miles long. D’Urban was also the one who claimed the prints continued from one side of the River Exe to the other side, two miles distant. It’s not clear if the river was frozen at this point, although it was frozen so solid by late February that an enterprising stove manufacturer ran pipes from the gas main onto the river ice and cooked an entire dinner for 30 on it while people skated all around him and probably tripped over the gas pipes. Moreover, the river is an estuary of the sea so has tides, and at low tide it’s barely a few hundred yards wide in some areas, or say 200 meters, and barely four feet deep, or about 1.2 meters.

Even at the time, D’Urban’s account was refuted by other locals, whose letters responding to South Devon’s letters were printed in follow-up issues of the paper. Apparently newspapers back then were like really slow social media. People wrote letters in response to other letters they’d seen in the newspaper, and other people wrote letters in response to those letters. Old timey people really needed Facebook. And cameras, because we don’t have very many sketches of the footprints and the ones we do have aren’t very detailed.

So what did the tracks really look like? As far as we know, most of the tracks were about 4 inches long, or 10 cm, and 2.75 inches across, or 7 cm. They did vary in size and shape from place to place, which argues that more than one animal made them and that hoaxers weren’t involved, since hoaxers would leave identical prints. I’ll put Ellacombe’s drawings of the prints, which he copied from newspaper reports, in the show notes to give you an idea of what they looked like. When you hear the word hoofprint it’s easy to think of a crisp, well-marked round hoof, maybe even with a horseshoe, but these prints were kind of wobbly in shape—not unexpected since they were all somewhat distorted by the night’s thaw and refreeze.

One of the people who wrote in to denounce some of D’Urban’s details was a Reverend G.M. Musgrave, vicar of Exmouth, and one of the things Musgrave also mentions is that he himself had suggested to his parishioners that the tracks were made by kangaroos escaped from a private menagerie. But, he admits, he didn’t actually believe this, he was only trying to stop his parishioners from believing that the devil had walked through their town.

The devil only started getting blamed for the footprints once it was clear no one really knew what had caused them. Lots of animals were suggested as culprits, most of which were about as likely as Musgrave’s kangaroos. Among the suggestions were badgers, rats or mice, hares, wolves, cats, monkeys, toads, or various birds. One anonymous letter-writer said that a friend had examined the tracks, noted that some of them showed claw marks, and suggested the animal might be an otter—mostly as a way to explain how the trail passed under low branches without disturbing them and through a six-inch, or 15 cm, pipe.

Other suggestions were even more outlandish, like the runaway balloon trailing a rope theory. Or the complex and largely irrational theory proposed in 1973 that seven Romany tribes conspired to lay the tracks in one night using stilts made from stepladders, in an attempt to scare some other tribes away. Or the 1972 theory that UFOs were measuring…something…with lasers and the tracks were left as a result, by lasers. Measuring things.

Leaving aside the theories that are clearly farfetched, like animals escaped from menageries and UFOs, and going with the assumption that whatever left the tracks was likely a real animal native to England, what might have left the devil’s footprints? I’m going out on a limb and suggesting maybe it wasn’t the devil.

Badgers, otters, and wolves leave tracks much too large to fit the bill. Toads are cold-blooded and would not be active in the snow. Birds do not leave miles of prints in snow at night, not even owls hunting mice on the ground, as they sometimes do. The tracks of deer would probably be recognized no matter how distorted the melting snow might have made them, and there are no reports of dew claw marks that deer prints show.

What about cats? Cats leave small neat footprints in snow with prints nearly in front of each other. With the brief thaw, feral cats might be out hunting for mice and other animals around houses and gardens, exactly where many prints were found. Cats can climb well, and a small cat might be able to accomplish some of the astonishing feats reported, like getting through dense hedges or larger pipes. And we do have a witness whose report is interesting. A tenant of Aller Farm in Dawlish, the only person we know to have been outside during the night in question, said that his cat had left tracks in the snow, and that the thaw and rain melted them, after which they froze again into small hoof-like shapes. So it’s possible that at least some of the prints were made by cats.

Rats sometimes hop through snow on all four feet, leaving deeper impressions that do look remarkably like the hoofprints seen. Rats can also get through quite small spaces and climb well. The main drawbacks of this theory are that hopping rats leave clear tail prints and rats don’t hop for miles. Rats also usually leave prints larger than the ones found. But again, it’s possible that at least some of the prints were made by rats.

Finally, what about mice? When I was a kid, this argument seemed ridiculously weak. I had pet mice. I knew there was no way a mouse could leave a horseshoe shaped print in the snow. But I was only familiar with pet white mice and house mice. There’s a type of mouse common throughout Europe that I think might be our culprit. Let’s find out why, and learn about the wood mouse.

The wood mouse, also called the long-tailed field mouse, is as adorable as the otter but won’t kill you. It’s a cute little rodent with a long tail, sandy-brown or orangey fur, white or gray belly and legs, and big ears. Not counting its tail, it’s about 6 to 15 cm long, or 2 ½ to 6 inches long, and its tail can be as long as its body. It mostly eats seeds and nuts, although it will also eat roots, shoots, berries and other fruit, moss, fungi, snails, and insects when seeds aren’t available.

Like many rodents, it discovered a long time ago that humans are useful nuisances, so it frequently lives around houses and barns, although not usually in houses. It generally lives in burrows it digs in fields, gardens, or among the roots of trees, although sometimes it will make its nest in birdhouses, hollow logs, or in thick vegetation. The nesting chamber of a mouse’s burrow is lined with leaves, grass, and moss, and it may also dig chambers where it stores extra food.

In warm weather wood mice aren’t very social, but in winter they will sleep in pairs or groups to stay warm. They don’t hibernate, but in especially cold weather they become torpid. They’re nocturnal animals, good climbers, jumpers, and swimmers.

While it forages, a wood mouse will pick up small items like leaves and twigs and place them in conspicuous locations to mark certain areas. As far as researchers know, wood mice and humans are the only animals to mark trails with items, known as way-marking. A mouse’s typical winter territory is around 2000 square meters, or half an acre.

All this is interesting, but why do I think the devil’s footprints were mostly made by wood mice? Well, wood mice flee from predators by hopping on all four legs. They’re built like tiny kangaroos, with long hind legs and comparatively short forelegs. I had a hard time finding information about wood mice jumping, just references to their ability to jump sometimes quite long distances. Then I found an awesome site by a photographer with lots of action shots of the wood mice around their garden. I’ll put a link in the show notes. Unfortunately the page hasn’t been updated for a while, but it’s full of photos of mice in mid-leap. The photographer puts food out and apparently sets up cameras that react to movement—like mini trail cams. It’s clear just from these shots that wood mice can and do jump a lot.

Unlike a rat, a jumping wood mouse doesn’t leave much of a tail mark in snow. It can also keep up this hopping gait for a long time, which it would do since it’s a more efficient way to travel through snow taller than the animal is high. It jumps with its feet together so the print it leaves behind roughly resembles a V shape where the two sides of the V don’t connect. Any amount of thawing and refreezing can turn that print into a cloven hoof print or a donkey-like hoof print.

Moreover, mice can get through extremely small holes and pipes, can burrow straight through haystacks, can hop across roofs without making noise. Where people reported finding prints that vanish in the middle of open fields, the mouse could have disappeared into a burrow, been picked off by an owl, or just stopped hopping and started walking, leaving footprints so small and shallow they likely didn’t survive the thaw.

But why were there so many prints on this particular night? Remember, the winter had been harsh but that particular night there was a brief thaw. It’s very possible that even slightly warmer weather would bring hungry mice out in droves to forage. The unusual weather conditions distorting otherwise barely noticeable tracks into hoofprints, and human nature, did the rest.

But if that’s the case, why haven’t people reported seeing the same mysterious prints at other times? Actually, they have, both before and after 1855.

The earliest account anyone has found in the papers was an 1840 report in the London Times of strange prints in Scotland. Other accounts date from the 1850s, 1890, the 1920s, the 1950s, and so on until 2009.

Some of these accounts are of much larger prints, some don’t match up with the hoofprints seen in 1855, but some sound similar. In 1957, for instance, when Lynda Hanson in Hull was a child, a line of cloven hoofprints 4” long and 12” apart appeared in her family’s garden in about an inch of snow that had fallen overnight. They vanished in the middle of the garden. Ms. Hanson notes that the family dog didn’t bark. He probably would have barked at the devil. Just saying.

Another interesting report comes from a sighting in late 1962 or early 1963. Zoologist Alfred Leutscher, writing in the April 20, 1965 edition of Animals and expanding on a talk he gave to the Zoological Society of London about the sighting, explains some tracks he found in Epping Forest. I’ll quote from his description. “It was during a search for snow tracks in Epping Forest, in the severe winter of 1962-3, that I came across dozens of trails of the wood mouse, each consisting of small ‘V-shaped’ marks regularly spaced out and conforming to the measurements which were given a hundred years ago. When I found them I was totally unaware of their significance.”

There are problems with this, of course. While the account says the tracks were identical to those reported in 1855, they’re described as V-shaped rather than hooflike. I have no doubt Leutscher’s prints were from wood mice, but whether they were the same type of thing seen in 1855 in Devon, we can’t know for sure since the reports from the 1855 sighting are so unclear.

Like I said, while the wood mouse is a good candidate for what caused the devil’s footprints, it’s not perfect. Why would mice be hopping around on snow-covered roofs, for instance? But nothing else fits the evidence we have as well as the wood mouse does.

In 2009, Jill Wade of North Devon woke up to snow and found a line of hoof-like prints across her garden. A zoologist who examined the prints suggested they might be those of a rabbit or hare, although since the prints were only 5” long, or 12.5 cm, that would have to be a little baby bunny. But the great thing in this case is we have photographs. Good ones. I’ll put one in the show notes. It definitely looks like a hoofprint—and it also looks like little animal legs made it.

One interesting thing. The wide part of a wood mouse’s print, the one that would make the rear of a hoofprint, is actually at the animal’s front. So anyone following the devil’s tracks in 1855 was following them backwards. Assuming the culprit really was a horde of hungry wood mice, and not the actual devil.

You can find Strange Animals Podcast online at strangeanimalspodcast.com. We’re on Twitter at strangebeasties and have a facebook page at facebook.com/strangeanimalspodcast. If you have questions, comments, or suggestions for future episodes, email us at strangeanimalspodcast@gmail.com. If you like the podcast and want to help us out, leave us a rating and review on iTunes or whatever platform you listen on. We also have a Patreon if you’d like to support us that way. Rewards include stickers and twice-monthly bonus episodes.

Thanks for listening, and Happy Halloween!

 


Episode 008: The Loneliest Whale and Other Strange Recordings



This week’s episode is a collection of strange animal sounds, some unknown, others identified. We start with “the loneliest whale.”

A blue whale. Not the loneliest whale, as far as anyone knows.

A tarsier:

This fox can see into your soul and does not like you:

Show transcript:

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

One of the great things about making my own podcast is that I’m the one who gets to decide what topics to cover. I love podcasts about unexplained sounds captured on audio, so this week’s episode is just that.

With one or two exceptions, I’ve tried to keep to sounds that are definitely or probably made by animals. I’ve also tried to dig a little deeper to explore some sounds that I haven’t heard covered in other podcasts. I waded through a million pop-up ads so you don’t have to.

First, let’s talk about a whale you’ve probably heard of. It’s frequently called the loneliest whale. The story goes that this whale is lonely because its voice is too high to be heard or understood by other whales. It calls but never gets a response.

But that’s actually not the case. Its voice is higher than other blue whales, fin whales, and humpback whales, but they can certainly hear it, and for all we know, they answer. Since the individual whale hasn’t actually been spotted, we don’t know if it travels alone or with other whales.

The loneliest whale was first detected in 1989 by the US Navy listening for submarines in the North Pacific, then again in 1990 and 1991. At that time the recordings were classified due to the cold war, but in 1992, some were partially declassified, and word about the whale got out. The calls vary but are similar to blue whale calls. The main difference is the voice’s pitch. The loneliest whale calls at 52 hertz. That’s slightly higher than the lowest notes on a piano or tuba. Blue whale songs are typically around 10 to 40 hertz. The whale’s voice has deepened over the years to around 49 hertz, suggesting that it has matured.

Suggestions as to why this whale has a different call include the possibility that the whale is deaf, that it’s malformed in some way, or that it’s a hybrid of two different species of whale. Fin whales and blue whales do interbreed occasionally, but no one has successfully recorded a hybrid’s calls.

Whale researchers think the recordings seem to be of one individual whale, but in 2010, sensors off the coast of California picked up lonely whale type calls that might have been made by more than one whale at the same time. One suggestion is that blue and fin whale hybrids might be common enough that they band together. This seems a little far-fetched to me, but I’m not a whale expert.

The loneliest whale’s migratory patterns suggest it’s a blue whale. So do its call patterns, if not its actual voice, but no one has recorded the whale’s song since 2004.

A documentary called “52: The Search for the Loneliest Whale” is currently in production. There aren’t any dates listed on the official site, 52thesearch.com, but it’s supposed to be released some time this year, 2017. [Note from 2020: it doesn’t appear that this has ever been released.] The film’s expedition has concluded, although we don’t know yet whether the scientific and film teams actually identified the loneliest whale or recorded it.

Here is the call of the loneliest whale. This recording has been sped up 10x to make it easier to hear. The original recording is barely more than a rumble, depending on how good your hearing is and how good your speakers are.

[whale call]

And just for fun, here’s a recording of an ordinary blue whale, also sped up:

[another whale call]

Now let’s go from the largest mammal alive to one of the largest land mammals alive, the elephant. In 1984, biologist Katy Payne, a pioneer in the field of bioacoutics, was at a zoo in Portland, Oregon to give a talk about whale songs. While she was there, she visited the elephant exhibit and noticed that every so often she felt what she called a throbbing in the air. She got some recording equipment and came back to the zoo, recorded the elephants, and sped up her recording. Sure enough, the elephants were making sounds below 20 hertz.

She pursued the finding with wild elephants in Africa. It turns out that elephants communicate not only with the familiar trumpets and squeaks, but in infrasound—that is, sounds below the lower limits of human hearing.

Infrasound can travel a long distance, especially useful in forested areas with limited visibility, and at dusk and dawn when atmospheric conditions help propagate the sound waves so they can travel as far as six miles away [9.6 km]. Females in estrus make a special call to bull elephants, for instance, attracting potential mates from a long way away.

Here’s a recording of elephant rumbles—again, sped up so we can hear it:

[elephant sounds]

Other animals communicate in infrasound, generally large animals like rhinos, hippos, giraffes, and of course whales. Many more communicate in ultrasounds, sounds above the top hearing range of humans, about 20 kilohertz. Bat radar navigation and sonar navigation sounds made by many species of dolphins and toothed whales register in the ultrasonic range, as do many insect calls. But there are other much more surprising animals that communicate in ultrasound.

The Philippine tarsier is a tiny primate only about five inches tall [13 cm], a big-eyed nocturnal fluffball with long fingers. Researchers studying the tarsiers wondered why the animals frequently opened their mouths as though to make calls but produced no sound. Sure enough, they’re communicating at ranges far too high for humans to detect—higher, in fact, than has been discovered for any terrestrial mammal.

The Philippine tarsier most often communicates at 70 kHz and can hear sounds up to 90 kHz. Researchers think the tarsier uses its ultrasonic hearing to track insects, and communicates in frequencies too high for predators to hear. Here’s a tarsier call, slowed down so we can hear it. I’ll keep it short because it’s super annoying.

[tarsier call]

Another animal that uses ultrasound is the cat. Domestic cats can hear sounds up to 85 kHz. Some kitten calls fall in the ultrasonic range, so the mother cat can hear her babies but many predators can’t. Cats have evolved to hear such high sounds because many rodents communicate in ultrasound. Male mice, for instance, sing like birds to attract mates. Here’s an example, slowed down so we can hear it:

[mouse singing]

But so far these are all known animals, or in the case of the loneliest whale, probably known. What about truly mysterious sounds?

Probably the most famous mystery sound is the bloop. It was recorded by NOAA in 1997 off the tip of South America. It’s an incredibly loud sound, much louder than the loudest animal ever recorded, the blue whale, and for a long time, people speculated that it might be an enormous unknown animal. Unfortunately, or maybe fortunately because no one wants to awaken Cthulhu, NOAA has identified the bloop as the sound of an icequake. That is, massive iceburgs breaking apart. Here’s a clip of the bloop, sped up so we can hear it:

[the bloop]

Another solved mystery sound has been dubbed “bioduck,” since it sounds sort of like a robotic duck. It’s been recorded since the 1960s, when it was first reported by submarine operators in the southern ocean off the Antarctic. It’s common, heard almost year-round near Antarctica and Australia, and was not from any known human-made source. Then, in 2013, whale researchers attached suction-cup tags to two Antarctic minke whales. While the tags remained in place, they recorded not only where the whales went, but the sounds they made. And to the research team’s astonishment, both whales made bioduck calls. This finding is important, not just because it cleared up a longstanding mystery, but because it tells us a lot about the Antarctic minke whale that wasn’t known. Researchers thought the whales only lived in Antarctic waters part of the year. Now they know that some whales remain year-round while some migrate near Australia. They can also make better estimates of whale populations now that they can identify this distinctive call.

The Antarctic minke whale is a baleen whale that grows to around 40 feet [12 m], but usually much smaller. It’s gray with white belly and mostly eats krill. This is what they sound like:

[minke whale call]

In our sea monster episode a couple of weeks ago, I shared another baleen whale call, this one from an unidentified species. It’s been dubbed the bio-twang and has been recorded in the Mariana trench in the western Pacific year-round in 2014 and 2015. Researchers suspect the dwarf minke whale, but they don’t know yet.

[mystery whale call]

To get out of the water for a moment, in 2012 a supposed bigfoot recorded started going around the internet. It was supposedly recorded on a cell phone in the Umatilla Indian Reservation near Pendleton, Oregon. It’s more likely to be nothing more exotic than a red fox.

Here’s the unknown scream:

[creepy animal sound]

And here’s a recording of a red fox:

[equally creepy red fox sound]

To me the sounds are very similar. If you want to know how I know the red fox scream is actually a red fox screaming, google “red fox scream.” The first hit is a YouTube clip of a fox screaming. I pulled the audio from that one.

In 2014, an unknown animal was recorded in Lake Champlain in Vermont. Dennis Hall, who claimed to have spotted the lake monster known as Champ in 1985, and Katy Elizabeth, who runs an organization known as Champ Search, made the recording and thought it might be from a beluga whale.

But while Lake Champlain is connected to the ocean, a whale would have a hard time reaching the lake due to canals, and would most likely have been spotted either on its way to the lake or once it arrived. Certainly it would have been spotted once it died from trying to live in fresh water.

Other recordings of clicking and squeaking sounds like those of beluga whales have been recorded in the lake in the past, including by a Discovery Channel team researching Champ. In 2013, Dr. Lance Barret Lennard from the Vancouver Aquarium Marine Science Center, and an expert on whale acoustics, examined some of the echolocation patterns. He determined that not only are the recordings not of beluga whales, they’re not from any kind of whale. They’re probably not mammalian in origin.

Some turtles have been found to produce underwater signals that may be a form of echolocation, and many fish make clicking and drumming sounds. But we don’t know what’s making the sounds recorded in Lake Champlain.

Here’s the 2014 recording:

[Lake Champlain sounds]

Finally, here’s a sound that’s not mysterious, I just really like it. It’s the song of the veery, an attractive but rather plain thrush. I’ve heard it in person while hiking at high elevations in the Smoky Mountains, and it’s completely ethereal.

If you listen closely, you can hear that the veery is actually making two sounds at the same time. The avian vocal mechanism, called a syrinx, is much different from a mammal’s larynx, and allows a bird to product more than one tone at a time.

[veery call]

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

Thanks for listening!