From the Vault: Squirrels, Part 1

We still hear from people like like on a weekly, almost daily basis, anytime there's anything squirrel related. Um, you know that that's what people post. And it's still delightful and I still enjoy squirrels. I'm I'm still writing the squirrel high from having you know, helped research and record these episodes totally. Uh. This episode originally aired August and we hope you enjoy it. Welcome to to Blow your Mind from how Stuffworks dot com. Hey, you welcome to

Stuff to Blow your Mind. My name is Robert Lamb and I'm Joe McCormick. And Robert, I got a question for you. Give me with it. What wild animal do you most associate with American founding icon Benjamin Franklin's Gonna Be the Turkey, had that whole song about it, right in seventeen seventy six. Oh yeah, were you in seventeen seventy six? Did you play Ben Franklin? I played Thomas Jefferson. Okay, community theater performance of it. Yes, that's that's who I was.

But you got to be the boring guy without a sense of humor, yes, but with with bright red hair. That was the main appeal. And U. Ben Franklin was played by a local attorney named Ray Frele Ray Freely, Ray f He did wonderful job. So I'm glad I had the part I had. I was more suited for just red haired and kind of boring. Uh. You know Jimmy Jefferson, Timmy Timmy. Yeah, he is kind of a Timmy and that isn't he? He like he? There are scenes where he plays the violin. Right did you play

the violin? Oh gosh, I don't remember. I remember scenes where I had pretending to write in what paper? Okay, Uh, sorry, we got sidetracked here, But there is a song in there where Benjamin Franklin he suggests that the u S National birds should not be the should not be the eagle, and should not be the dove, but should be the turkey because it is a most majestic bird. And I've found no evidence that Franklin actually suggested that the national

birds should be the turkey. But Franklin was all about some turkeys. Especially it was all about killing turkeys, and especially it was all about killing turkeys with his favorite

technological toys, the Layden jar. Uh. We we've talked before in our episodes about the early days of electricity about that that barbecue Franklin hosted where he wanted to kill turkeys with with electrical shocks and then roast them with an electrical jack and then uh and and I guess I don't know, char their skin with electrical fire from a bottle. It was a rousing affair, I'm sure because Franklin actually ended up electrocuting or not electrocuting, but he

shocked himself very badly. See why isn't this our Thanksgiving tradition should be a big turkey electrocution every year? Wait, a lot of people use electric stoves. I guess that's kind of closed, but it's not quite as a shocking right, you should be getting the jumper cables and going out to the yard with a gobbler. Yeah, no, pardon for you, all right. So if the if the turkey wasn't his favorite animal, what pray tell? Was it? Well? Who knows

if it was actually his favorite animal. But the animal I now most associate with Ben Franklin is the squirrel, because Robert, did you know that Benjamin Franklin carried a squirrel across the ocean to Europe? No? I did not know about this. He had a pet squirrel named Mungo. And yes, this is all true. Benjamin Franklin had a pet squirrel named Mungo that he kept in a cage.

They got killed by a dog named Ranger there. And he wrote a letter to Georgiana Shipley in seventeen seventy two where where he said, I lament with you most sincerely the unfortunate end of poor Mungo. Few squirrels were better accomplished, for he had had a good education, had traveled far and seen much of the world. In other words, I I put it, put him in a cage and carried him. I don't know an oceanic journey. There's some ironies in this story that we can tease out in

the second. In fact, Benjamin Franklin wrote a poem of lament is like an elegy for poor Mango. I wonder if we should do a reading of this poem for Mango. What do you think? Why don't really have a good Benjamin Franklin voice? Neither do I, But I can give it a shot. Alas poor Mungo, happy wort, Thou hatst thou known thy own felicity. Remote from the fierce, bald eagle tyrant of thy native woods, Thou hadst not to fear from his piercing talents, nor from the murdering gun

of the thoughtless sportsman. Safe in his wired castle. Grim all can never could annoy the grim. Balkan, of course, is the which is familiar the cat from Macbeth. I think it is also just a word for a cat.

But yeah, so continues daily worth. Thou fed with choicest viands by the fair hand of an indulgent mistress, but discontented Thou wouldst have more freedom too soon, alas didst thou obtain it, and wandering fell by the merciless fangs of wanton cruel ranger learned hints ye who blindly wish for more liberty, whether subjects, sons, squirrels, or daughters, that apparent restraint maybe real protection, yielding peace plenty and security.

You see how much more decent and proper this broken style, interrupted as it were, with size, is for the occasion than if one were to say, by way of epitaph, here scug lie snug as a bug in a rug. Scug is an antiquated word for squirrel. I bet you

didn't know that one either. I didn't. By you know, I feel like a lot of people by by the time we're done with the special two part exploration of the squirrel, I think some people are going to adopt skug as an appropriate a bit of terminology for these strange furry creatures that for many obviously fill our backyards

in our lives. Robert, I am so excited to talk about squirrels for two whole episodes because I would never have imagined there were two episodes worth of startling squirrel knowledge, and oh boy, is there? Yeah, there is. But before anybody and it thinks I'll skip the squirrels, No, no no, no, no, stick with the squirrels, because some of this information is shocking. It will change the way you see the squirrel. The squirrels are not what they seem. You're right about that,

they are not. Yeah, this is not just gonna be like two episodes of squirrel minutia. This is gonna be episodes that redefine what these animals are and what they are up to in your immediate and ironment. They may shake your faith in the goodness of the world around you, right,

you know. Well, one thing that that I've I've noticed about the squirrel is it, of course, for many of us, the squirrels everywhere, Like like, how often do you see squirrels, Joe, Yeah, you see them more than any non human animal who is not your pet, probably, I mean, depending on where you live. But at least we we do. Yeah, Like with us, they're constantly scaring around our yard and on

our fence. We have a number of bird feeders that we that that my family we like to we're having breakfast or dinner together, we like to watch the birds out there, and of course the squirrels come. You can't keep squirrels away from a bird feeder in the same way you can't keep squirrels out of out of a garden you can try, but they are tenacious. They have an insatiable mammalian quality, a mammalian vitality that the birds

just do not have. Even though we we love birds and we've explored you know, when when you put a bird feeder out, you wonder why the squirrels always seem to take it over, And it does seem to have something to do with their mammalian craftiness. And that's despite the fact that birds are often craftier than we expect. Yeah, I mean it is. I I root for the birds, though when the birds drive the squirrels away, but then the squirrels are just going to get in there and

also have their their meal as well. Um. Another thing that I always noticed about the squirrels is that, yeah, for for many of us, we we barely noticed that notice them anymore, and we're certainly not really we don't get hung up over their cuteness. Though they do have like large kind of cute eyes, yes, and they have big fluffy tails. They're not a chipmunk. A chipmunk is I think, objectively cute, whereas the squirrel is a little larger and a little more grotesque and a little more

like a tree rat. There's a reason the rescue rangers are not squirrels, and they just be less cute that way. But but one thing I noticed is that when you have people who are not accustomed to squirrel suddenly encountering them, tourists from Afar, they'll they're just totally won over by these scurring creatures and they're pointing at them, and then of course they they may give in to the temptation

to feed them. Which means if you go to a place like the Grand Canyon, where you know you have you have tourist from around the world coming to to see this natural um landscape that's just truly inspiring uh scene to behold. People are also gonna encounter the squirrels. They're gonna end up beating the squirrels, even though everyone

tells them not to. And then you have situations like the one my wife and I encountered on a hike into the Grand Canyon where we set down for a second, we're gonna share some some snack mix, and then the squirrel comes and the squirrel starts climbing on us on our bodies to get to the snack mix. Because it's become so accustomed to eating food given to it by humans. Uh. It was just absolutely terrifying, especially when you watch like

the fleet jump off of its nose. It's only a matter of time until they can pull a switchblade on you, exactly. They're like, they're they are tenacious and you should and you feed them at your apparel, especially if they're there. There are lots of drop offs that you could plummet from. And that's not even getting into disease issues. I apologize it was ranting a little bit. Oh no, no, please rant on. I've been ranting about them a bit as my family watches the bird feeder as well, to the

point that my my son told me recently. He's he's six years old, and he he said, actually, Dad, uh, the squirrel is the king of the rats, which, um, well, I disagree with. I think the rats are truly the king of the rats. They've earned that that reputation, and they've earned that crown. Yet at the same time, yes,

squirrels are incredibly good rats in many respects. Well, there are many respects throughout especially mythology, but in human history, where there is some correlation between level of authority and physical altitude and so If the squirrels are in the trees above the rats, that would seem to signal that they are the lords of the rat world, and the rats on the ground below must do their biddings right.

They have the height advantage. The squirrels are the wizards up in their ivory towers, and the rats are the peasants that, you know, thank you Lord, kind of guys who go out and do what they're told. But yet there is an honesty in the rat. We look at the rat, and sometimes we judge the rat too harshly, It's true, But when you look at a rat and you know what the rat does. The squirrel, however, as we will explore in these episodes, the squirrel is not

what it seems. The squirrel has managed to to pull one over on us. So by now you may be going, Okay, what is the secret squirrel knowledge? I've been I want the squirrel noses let me into this religion. So I guess we should pave the way to divulge that knowledge. So let's enter the kingdom of the skugs. So what are what is a good skug? What what is a skug?

At its most basic nature? Squirrels are a family of rodents. Specifically, they comprise the taxonomic family Scura day and that includes ground squirrels, tree squirrels, marmots, chipmunks, flying squirrels, and a few other varieties. This also includes the so called oriental giant squirrels, the black giant squirrel, the Indian giant squirrel, the grizzled giant squirrel that's real grizzled yea, and the likely extinct cream colored giant squirrel. Many additional varieties roamed

in prehistoric times. Uh and plus this family also includes groundhogs and prairie dogs. But when most people refer to squirrels, they're probably gonna be talking about common varieties, most often of the tree squirrel and the ground squirrel. And so these are the varieties we're gonna be talking about most in this episode. And so squirrels are found all over the world. Their native to every continent except Antarctica in Australia. But of course humans tend to take their rodents with

them where they go. So humans introduced squirrels to Australia and now they're everywhere on Earth accept Antarctica. So I think maybe we've been burying the lead. We should not Bury, the lead part one of this two part exploration. One of the main things you're gonna learn is that you have probably been too trusting of squirrels if you were like I was. I used to look out at the squirrels of my yard and think about them like Benjamin

Franklin's Poor Mungo. This this victim, this poor little victim creature that could be eaten by a dog and was a harmless, sweet little herbivore gathering nuts and hiding them and just going about a peaceful life without ever bothering anybody else. But the fact that blew my mind is that squirrels are not, in fact strictly herbivores. Some not

very strictly at all. That's right. And uh, and I have to say, right before we we actually researched this episode, I had this revelate revelation as well through the bird feeders that we put out. Because one of the things we put out, in addition to you know, a few different types of bird seed aimed as particular birds, we also put out meal worms, and these dried, dried out worms like you would feed chickens, and birds generally love

them as well. But then we started noticing that the squirrels would just eat the ever loving hell out of

those meal worms. We fill up this little cup, and you know, squirrel would come and you know, surreptitiously eat one, and you know, grab one, get to a place where it could be on the lookout for hawks or whatnot, and then go down and get another one, and then eventually give up on any pretense of looking out for hawks and just just go face down into a this cup of meal worms and just eat absolutely all of them.

And we were a little stounded because we were, like, I had we had no idea that that that squirrels eat me, But clearly these squirrels really love meal worms. Well you know, I might not have predicted that, but at least meal worms. I look at that, Okay, I'm like, it's a worm. I guess maybe a lot of things might eat a worm, right, right, I don't know. It's it's like that's like the cracked corn of the animal kingdom, right, yeah, it's there, you eat it. It makes sense, all right.

So maybe they're not strictly herbivores, you know, they're they're they're omnivores that will that will eat a worm here and there, but subsequent reading has has revealed that that it goes far beyond meal worms. Uh, they'll eat insects, reptiles, birds, and mammalian flesh if they get a chance. Gray squirrels and eastern chipmunks are noted nest raiders. Gray squirrels will even eat each other. It seems squirrels are also capable

of killing adult birds. Uh, even the cute chipmunk. Again, the objectively cute chipmunk is a natural born killer, as studies have found meat and upwards of chipmunk survey meat in them, not just in their bodies like the valley. Now, that sounds so crazy. That makes me think, wait a minute, are we just dealing with like uh, like urban legend kind of observations here. Like I've read stories that I don't believe about squirrel attacks, like the idea that squirrels

will will take down deer and kill them. That's right. According to a two thousand fourteen Popular Science article, the tufted ground squirrel of Borneo is said to wait on a low branch for passing deer and then jump out onto them and bite the jugular vein, and once the deer is bled to death from this bite, the squirrel disembowels the deer and eats the contents of the stomach as well as the heart and the liver. And I do want to just drive home. This is not this

is far from any kind of a verified observation. This is very much seems to be in the realm of love of urban legends. This account was told by local hunters who find the remains of the squirrel slaughtered deer and then supposed squirrel, supposed alleged squirrel slaughtered deer. And then they also attest to the hearts and livers having been eaten from domestic chickens. Again, uh, fingers pointed at the squirrels. This almost reminds me of like the Coppa legend,

right reaching up through your anus to pull your liver out. Yeah, there, there seems to be a lot of making sense. Are trying to make sense of stranger remains, but by making several leaps uh in uh in your logic here, as opposed to saying, well, it was probably some sort of scavenger that came into that. No, it was probably a

ferocious and strategically vicious squirrel. Now, on the other hand, supposedly these squirrels could I mean, if you happen to put your finger in their mouths, say, they could do some damage. Yeah. In fact, the author of that article, Douglas Main, points out that those those squirrels do pack quite a fierce bite, and that the giant squirrel Ratufa a finnis is known to stalk and prey on birds. Okay, but the idea of a squirrel attacking and taking down

an adult dear, I don't know. I highly skeptical. I don't buy it. It sounds like one of those kind of hunter legends. Yeah, it reminds me a lot of cattle mutilation stories. You know, someone finds again, someone looks at the remains of an animal. There's something kind of weird look going on, and so you jump to uh, totally implausible explanations such as an alien being performed at an autopsy in the middle of a cow field, or squirrels or hunting impacts. But how much could you really

learn in the middle of a cow field. I don't know. It's it seems like as guided research. I would think they would want to remove to some kind of sterile environment where they could control all of the autopsy element I don't know. But but but I don't want to lose the track of the The important revelation here, uh, that we'll get back to, and that is that squirrels

do seem to hunt some of the time. Well, we will definitely look at more evidence of that in a minute, but before we do that, we should look at one other apparent I don't know, rumor legend, the kind of thing, uh, this idea that sometimes squirrels will attack and take down dogs. Yes, I was reading a two thousand five BBC article that reported that that a local Russian media report had indicated that a pack of squirrels bit a stray dog to death in the city of Lazo. So again local Russian media.

But here's here's a gym from the story. Quote A pine code shortage may have led the squirrels to seek other food sources, although scientists are skeptical. So in. In fact, a scientist in the region, one Michael Toof, said that while attacking a bird's nest for protein was reasonable behavior, for to expect of a squirrel chewing a dog to

death was quote absurd. Uh. In a quote that reads like something from a horror movie poster, he said, quote if it really happened, that things must be pretty bad in our forest. I can hear that in the Don la Fontaine voice. Yes, things must be pretty bad in our forest. Wait, that's not Don la Fontaine. Who's that one? I don't know. I don't really know them by name. I'm sorry. I'm sorry to say in a world where squirrels chew dogs to death, Russian media is the only

one brave enough to report. But the thing about these stories is that, yes, I'm I'm not convinced that squirrels are killing dear. I'm not convinced that they are taking down stray dogs. I I also am skeptical of that. I'd wonder though, I mean, maybe if the dog is, like, I don't know, sick and already almost dead, that might be a different kind of thing. I find it hard to believe that a pack of squirrels would actually attack

a dog that could move exactly. Yeah. But if you but the thing is, you start looking around at different papers, particularly Journal of Mammalogy papers, mostly from the twentieth century, You'll find a number of different papers that look at

carnivorous ground squirrels and carnivorous activity among squirrels. Uh with titles such as Carnivorous behavior in the Mexican ground squirrel or Carnivorous ground squirrels on St. Lawrence Island, Alaska, or food habits of the Antelope ground squirrel in Southern Nevada. Also the Franklin ground squirrel and its relationship to nesting ducks.

The relationship is not a friendly one. It's complicated. That paper Carnivorous ground Squirrels on St. Lawrence Island, Alaska has some choice descriptions, and it here commentating on some some

previous research by other investigators. Quote. During his excavations at the old village site of Kakuliak gated a few miles at east to the present village of Savunga, he observed some adult ground squirrels eating the old partially dried and partially frozen lumps of whale and walrus meat, which we excavated at an approximate depth of eight feet under the surface.

What eating whale and walrus meat? So they didn't bring down these whales, They didn't bring down these walruses, but they were more than happy to feast on their like rubbery dried flesh. Also from that paper, there was a part where they were mentioning the work of this previous researcher who reported having seen a ground squirrel quote eat a freshly killed mouse which had been shot by the teacher's son from Savunga. So you go shooting mice in Alaska.

Who knows what's going to happen. All right, let's go ahead and take a break here, and when we come back, we're going to get into my favorite carnivorous squirrel paper that I ran across in our research. Thank alright, we're back.

So before we get into squirrels as predators, I just wanted to mention another paper I looked at about squirrels eating meat, and this was from the Journal of Parasitology from nineteen fifty six by Raws and other authors called the occurrence of larvae of trick and Ella spiralis in Alaska mammals. So this is a paper looking at the prevalence of this parasite of trick and Ella spiralis in

the mammals of Alaska. And trick and Ella spiralis is the nematode worm responsible for trickn nosis, which you may have heard is the you know, the reason that you should not eat pork tartar, though not to demonize a lot of pork is much safer these days than it used to be. So some of those fears are based on older, older ways of doing things and food. But you're not getting tricken noses eating peanuts. That's true even

if you're a squirrel. In fact, so when the researchers found one ground squirrel and four red squirrels infected with trick and ella, which you can only get from eating infected meat, what's going on here? It's clear what's going on. So the ound squirrel that with the ground squirrel, they say, although primarily herbivorous Sit tell Us undulatus, and that's the ground squirrel they were looking at, also consumes mammalian flesh

when available. We have observed this behavior in northeastern Alaska and in the Talkeitna Mountains, where remains of voles were found in stomachs and cheek pouches of these squirrels. Such animals feeding upon carcasses of dogs or Arctic foxes would of course be exposed to infection because the dogs and the foxes can get they can get the worm, their meat gets infected, and then the squirrels go and eat the dead dogs and foxes. That's pretty messed up. The

other one, though, is the red squirrel. How did the red squirrels get them? Quote? We have observed red squirrels feeding upon the flesh of the Snowshoe hair, carrion, and mammalian bones are often found among the food items stored by these animals for winter use. They no doubt eat any warm blooded animal they are able to capture and kill. I don't know why they keep the bones though. Why do they keep the bones? Are they gonna make soup?

What's gonna happen? They're gonna eat those bones, Joe and I know this because because because it's mentioned in in this excellent paper that I came across from. It was in an addition of the Great Basin Naturalist titled Squirrels as Predators by J. R. Callahan. So this is predators now. But previously we've been talking definitely about eating carrion. Right, they'll find a dead animal, they'll find dead insects, whatever,

they'll definitely eat that. But he's certainly to eat to say, a worm or a snail, a creature the size of a squirrel was hardly predation. I mean, if I if I ate a snail, I wouldn't call myself a predator, right, but this is but here you're talking about seeking live prey, killing it, and eating it. That's right. So I'm gonna go through some of the major points of this paper, but it's out there. It's it's obtainable if anyone else

wants to to read it in full. So we pointed out that squirrels are opportunistic predators that are not morphologically specialized for the role. You can see that they don't have like wolf teeth. Yeah, and I think that's one of the reasons it's so shocking. Yeah, they don't look like predators. They don't. They don't look like a little tree dogs or or some sort of a tree cat. You know. Uh it is it surprises us to think

of them chewing on meat. Well, it's interesting how much this emphasizes sometimes the flexibility of the animal existence as opposed to other types of existence, where an animal might not be evolved to specialize as a predator, but given pressures on its survival and existence, it can adapt. So at the time of this publication, he says that not everyone accepted the idea. Frequent squirrel predation though it was already universally accepted that they do eat meat, but they

were they were just not observed praying all that much. Uh. You know, a lot of these reports come down to trying to figure out, you know, were they just scavenging meat, where they just eating something that was already dead, or did they or was it an opportunistic attack, or were they in fact stalking something? How did you get those

foles in your cheek pouches? Exactly? So, he he lists the different prey associated with a whole list of squirrel species, and the prey include the following, uh if but not limited to, birds, frogs, rats, lizards, rabbits, gophers, moles, snakes, fish bowls, ducks, wild turkeys bringing it all back home. Yeah, turtles, crabs, and salaman This is too good. Yeah, squirrels getting wild turkeys, rabbits, salamanders,

this is a whole buffet. Yeah. And he said that it wasn't entirely sure if tree squirrels were attacking live prey for meat per se, or for calcium and or phosphorus from the bones, but there were there there were also reports of him eating bone and antler or ignoring meat in favor of joints. Joints, so like they're trying to get like cartilage and ligaments and stuff. Interesting, Yeah,

he said. He points out to getting back to the morphology versus a behavior, says that one of the behaviors entree squirrel seems to be insinuation predation, which is largely utilized by invertebrates. Yeah, and so insinuation predation would refer to a predator lulling a prey animal into a false sense of security by appearing harmless and getting itself into an attack position or in close proximity without indicating that it's any kind of threat. The squirrels are not what

they say. It's true. There they are little spies in filtrating your safe zones just to get into your nest and steal your your wild turkey chicks or something. Now we'll get to the specifics of this in a second, but we're just talking about them eating bone and antler or ligaments. Other times they have been observed to focus on quote, brains of viscera and the flesh of the head. What the squirrels eating brains? Yes, this can't be real.

It is real. It is very real. Brains. So we seem to see far are more squirrel meat eating and predation in colder climates, and it's and it's far more rare among tropical species. And uh. Callahan lists some possible reasons for this. So calcium and other nutrients can be obtained from certain tropical tree barks. And then uh, and in these cases too, we see these same squirrels turning to predation when they are cage when they now have

access to those tree barks. Oh, I see carnivores and the tropics may also suffer more from stomach nematodes while colder climates demand more fat. And then there's also this, this sort of opportunistic predation might be a learned behavior that spreads through local populations of squirrels. Oh no, that's

interesting now. For example, in our recent episodes about urban evolution, we talked about how apparently learned behaviors can spread throughout populations of birds that live in an urban environment, say like the example of um birds that learned how to open milk bottle tops that were being left on people's doorsteps, right, Um, And then the spread throughout the populations. And so you have to assume if birds can learn in that kind

of way. Squirrels probably can too, except in this case instead of opening milk bottle tops would be what opening a vole skull to get the brains. Indeed, now there are key reasons though to eat live meat, because ultimately that's what we're talking about, praying to obtain live meat rather than depending on just scavenged and uh, you know,

meat and the flesh of the dead. So, for one thing, reproductive females may need the protein and or certain minerals more than the rest, and there are reports of lactating female specifically engaging in this sort of predation behavior. They might not be able to get the necessary calcium, phosphorus, sodium,

and nitrogen from seeds alone. Another hypothesis, which is weirdly reflected in that story of the Russian dog eating score earls, is that they may turn to meet to make up for seasonal depletion, such as during summer, or indeed some other reason for a lack of seeds. Okay, well, that would sort of fit the story, but we're not saying that makes it likely that they actually did take down an adult. I don't know, yeah, but that is a

that's a grain of truth there um. But going back to that Russian um naturalist, he said, yeah, things would have to be pretty bad in the forest for this to happen in a world. So, so we've been talking about how squirrels definitely will eat things that are dead anyway, Sometimes they'll eat carrion. Why why go to predation? Why must you go beyond just eating the dead that you find. Why do you have to do all these risks and spend all this energy trying to kill something that's alive.

That It's a great question one I had in One and one Callahan addressed because he points out that, yes, carrion certainly packs the nutrients uh, and it's it's also not capable of fight or flight. You don't have to worry about it fighting back, but cheaper date, right, But

it also suffers from nutrient content depletion. On top of that, other better predators and seasoned scavengers may beat you to the best parts of the you know, say that the dead you know rat plus those specialized scavengers, well they're probably better at dealing with the added bacteria and uh and you know what else sucks about carry on? It might not be there when you need it. So in our you know, sort of our you know, our urban

forest environments, uh, you know, or even our rural environments. Uh, squirrels can sometimes be seen feasting on roadkill, which Callahan points out is an artificial situation. It is very much a product of human technology. Do we have these dangerous roads uh? For animals? Animals get squished on them, and then squirrels are able to find meat there. And of course a lot of the meat is squirrel meat because they run out in front of our vehicles all the time.

So do they do they cannibalized carrion squirrel carryon? Yes? But okay, I'm just thinking about the body of a squirrel. I mean, as we were talking about earlier, as a squirrel is not has not been shaped by evolution as an effective predator, right that its body just is not a powerful killing machine. So how how does it get

this done? Well, you know, some of these these prey animals that it goes after essentially quasi prey, like frogs for example, those are and those are easy to explain, Like, there's a frog, it's not getting away from this larger squirrel. The squirrel can eat it. But then they're the animals that are going to put up a fight or run from the squirrel potentially, and that's where we see the birds, the rodents, and the rabbits particular, like these are all

going to be more challenging prey. So many researchers believe that true predation by squirrels must be just a rare occurrence, only done in the case of emergency, but growing evidence, Scallahan said, supported the idea that predation is a normal part of their behavior, though they are still opportunistic not

fundamental predators. So he's going, so you've got the idea that it's very rare, like it only happens on these bizarre, freak occasions, and then you've got the idea that they're evolved as fundamental predators and that's just part of their normal life. And he's going somewhere in between, right, yeah, he said, like, yeah, I mean he's saying that, for instance, you know, rating a nest when you can get a chance,

that's one thing. If you kill a competitor and then you're like, well I might as well eat part of them, get a little energy boost, That's that's another thing. But but here we're talking about something far more sinister. And

I do have to warn everybody out there. If you want to retain your previous false sense of security around squirrels, uh and there's sort of cartoon innocence, then you should probably stop listening right now because you cannot unhear the hypothesis that I am about to share with you, laid Amy Robert alright, so he points Callahan points out that it's a waste of energy to avoid a creature that doesn't threaten you. It's not surprising to see birds behave

defensively towards squirrels. Their hunger is likely seasonal. They're known retinest rators. But in other contexts, birds and other potential prey just ignore squirrels. And we see this all the time, you know, especially if you watch your bird feeder. But Callahan presents an interesting view on this and on the

stalking behavior occasionally observed in tree squirrels. This is not uh nest robbing behavior, but is linked to infrequent attempts at larger prey attempts, mind you, and often aborted attempts mere caricatures of stalking the Callahan finds rather conspicuous. He argues that it's possible that the effect of obvious. Repeated stalking is to habituate potential prey. In other words, it

is conditioning prey animals to disregard their attacks. WHOA, so this would not be something we're saying that the squirrels are doing consciously, but they've somehow instinctually learned to like to to sort of feign attacks all the time to get it to our potential prey animals. Larger prey animals are like, oh, whatever, it's just squirrels being squirrels. Oh yeah,

I mean they're not. They're not doing in a conscious sense the same way that we would do our humans would stalk something, but but they're doing it in the via their evolved behavior anyway. Callahan writes, if most squirrels acting like predators do not follow through, then prey should learn not to respond. This behavior is analogous to the hoarding of nuts in that the squirrel is hoarding prey confidence. Later, when normal food items are in short supply, the squirrel

can exploit this conditioning In the longer term. Selection for such behavior potentially represents an entry point to a new feeding niche, particularly in marginal habitats where tree squirrels may be more likely to resort to predation. In other words, beware the squirrels. I am never going to be able to see squirrels the same after this episode. Now, on the other hand, we don't like to demonize any type of animal here, and of course predation as part of

an Sure, we don't want to demonize predation. But this is shocking. I was not prepared for this. Squirrels, squirrels eating dead things, killing things and eating them that I don't know, my mind was not ready. Yeah, I I have to to say much the same. Again, we do we do say, we do warn everyone, do not mistreat squirrels, do not do not hurt the squirrels. Let the squirrels be. They will let you be. Squirrels are not going to

actually hunt you. Um, they're not going to attack your dog, right, Yeah, it's it's gonna be fine. Yeah, you're not really in danger from the squirrels. But I do have to say it made me rethink the meal worm thing, Like I feel I feel extra good about those squirrels eating the meal worms because I'm thinking I'm probably saving some bird eggs. Maybe I'm not. Maybe that's just just I'm just convincing myself this because I hate the idea of squirrels eating

eating bird eggs. But if they need meat, then let me give them meat in the form of meal worms. That's all I'm saying. Well, you could I don't want to make you feel bad. You could also be art officially inflating local squirrel populations such that if you ever stop feeding them, there will be a massacre in the oaks. That's right, the trees will rain blood from above. Well, let's hope it doesn't come to that. Speaking of that, though, has there ever been a squirrel horror movie? I've never

I've never heard of one. Well, you know, I looked around on this question, and there is a two thousand fourteen horror movie called Squirrels. But it sounds like it looks like it might be a little bit in the shark Nado territory, where it's a little bit too self aware to be my kind of horror film. But the better horror movie mascot for this episode would probably be uh Tromy the radioactive squirrel from Class of Newcomb High to Subhumanoid Meltdown. Uh. He's also in the third film.

You know, I never made it to the Class of Newcomb High. Sequels. How do they hold up? I have not seen the sequels either, but I I had to look up a clip of this, uh, this radioactive giant squirrel rampaging and knocking over cooling tower. Is that it is worth checking out. But you'll definitely want to see class of Newcomb High one first, you know, for you know it's concurity and check continuity of the of the saga. Alright, on that note, we're gonna take one more break and

then we'll be right back. Thank Alright, we're back. So we've been talking about opportunistic carry and eating and predation in squirrels, but I wanted to mention another less dramatical, less violent way, but still kind of weird and shocking way, that squirrels are opportunistic feeders. So let's let's turn our eye to the red squirrel. We mentioned red squirrels earlier. In some cases where red squirrels might be eating some dead animals, might be eating dead dogs or dead foxes

or something like that. But the red squirrel tammy Ascius Hudsonicus. Like other squirrels, they often tried to survive through winter by building up stores of food items that are called mast and mast is just all the edible fruits of the trees of the forest. It's acorns, pine cones, nuts, and so forth. And in the summer and fall, squirrels collect mast and store it in these caches to eat throughout the winter. And trying to survive by storing food

for the winter is sometimes a dangerous strategy. You can have an unexpectedly warm winter that can cause your food stores to spoil, or cases can sometimes be discovered by other animals. They're vulnerable to theft and opportunistic scavenging, and maybe most importantly, not every warm season offers the same kind of harvest. Trees in the forest actually tend to produce greater and lesser quantities of massed on multi year cycles.

So if you're a red squirrel and it's an off year where the harvests provided by the forest were very low or something else happened, what can you do? What happens if your supplies run low while it's still winter and you need some calories. Oh, I guess you can hope the tourists come by and feed you snack bars. But that's probably not a good uh, not something you can bank on, right, You can't bank on tourists. You can't bank on vole brains. You might not be to

come come across any of those. So what the red squirrel does, it's it's so. The red squirrel is common throughout the United States and Canada, and it has this cool survival technique. In a book called winter World, The Ingenuity of Animal Survival UH, the University of Vermont biologist and nature writer Burned Heinrich has written about this strategy

and what they do is they make tree candy. The red squirrel will find a sugar maple tree and it will make incisions in the bark of the tree with its front teeth, and this allows sap to drain out from the inside of the tree. And then after the sap runs out, its water content evaporates and it dries in the sun. And this leaves a sweet sugary residue on the outside of the tree that the squirrel can return and lick like a maple syrup lollipop to get some sugar in its system. There are lots of videos

of this happening. Some of the videos seem to show squirrels looking trees other than maples. I'm not sure, but uh that yeah, they're licking trees and it's pretty sick. It looks weird. Well, I don't know. This sounds like a refreshing dose of just cute behavior after the the brain eating and then the stalking that we just got through, So I'm all for them eating maple candy of their own construction. I wish I could have seen this without having read about it first, so I could just wonder,

what's going on? Did you see them biting holes in trees and then coming back and just licking tree trunks to death? But I guess maybe we should get back into more violent territories. Okay, So you mentioned earlier you gave this list of animals from that paper that squirrels will sometimes prey on or get into battle with, And one of the animals you mentioned was the snake the serpent.

So I want to talk about one particular squirrel snake relationship that is not so rare or infrequent or alleged, but instead is a well known evolutionary war spanning millions of years that has given birth to some amazing squirrel martial arts and battle tactics. So the squirreling question is the common California ground squirrel ODO sperma Phyllis b ch a. And it's found throughout the western region of North America, including California, Oregon, Washington, and the Baja Peninsula of Mexico.

And this utterly mundane squirrel faces a plenty of natural predators, including rattlesnakes like the northern Pacific rattlesnakes Croatalys viridus oreganus. By some accounts, the squirrels make up about seventy percent of the western rattlesnakes diets. And for years now, scientists, especially at the University of California Davis, have been discovering more and more of these ingenious, highly adapted anti predation techniques that the squirrels used to their advantage in the

Great War against the serpents of the West. All right, well, what are these techniques? Well, some are pretty straightforward. For example, research has found that adult ground squirrels inhabiting areas with greater rattlesnake populations have evolved a greater natural resistance to

rattlesnake venom. And you can see this is an evolved trade because meanwhile, squirrels in areas with few or no rattlesnakes have lost this resistance tends to go away, but sometimes California ground squirrels tend to go on offense against rattlesnakes, displaying aggressive behavior and harassing the snakes to keep them away from their young. Sometimes they'll go by petal and they whip their tails back and forth in the air, and this display that's known as flagging, and they'll kick

sand at the snake and so forth. And sometimes this aggressive display can discourage or scare off a predatory rattler. And sometimes the squirrels even attack the snake and bite it. There are videos of this you can look up as well. Or it's just like a standoff between a squirrel and a snake, and the squirrel is the attacker keeps biting the snake on the spine. Oh wow, so not even not just going after you know, another omnivore, herbivore, but

going after a predatory reptile. Here. Yeah, and you might think, wait a minute, how could a squirrel win in a standoff with a snake. Wouldn't that be suicide? It depends on the circumstances of the confrontation. Sometimes yes, but remember that the adult ground squirrels in the snake heavy regions tend to have this resistance to snake venom. And also the adult squirrels are generally not prime prey for the snakes.

Juvenile squirrels are are the much more vulnerable ones. They're the ones the snakes want, and snakes are less likely to try to prey on adults because they can put up more of a fight. More than that, some snakes are simply much more dangerous than others. For example, in a paper by Sways, good Row and Owings called anti Predator Responses of California ground Squirrels to Rattlesnakes and rattling sounds, the roles of sex, reproductive parody, and offspring age and

Assessment and decision Making Rules from two thousand three. Uh. Specifically, they found that quote larger, warmer snakes are more dangerous than smaller, colder snakes. Uh. So that might be kind of useful, But then again, how do you know what kind of snake you're dealing with. You can't look at a snake and say, well, that's snake is warmer than the other one. Apparently, what the squirrels do is they

listen to the rattle. So if you rear up on two legs, and you dance around aggressively and flag your tail and generally harass a rattle snake. It'll probably be rattling at you. Right, And if you listen to the sonic characteristics of the rattle, you can actually tell the difference between the rattle sound produced by big, warm, killer snakes and the rattle sound produced by small, cold, less

threatening snakes. Oh, it's it's It gives you a clue, or gives a squirrel a clue as to how how fast this snake would be if it starts uh coming after them. Yeah, And so they investigated this by they had a little study where they would playback rattle sounds from different types of snakes, and sure enough, squirrels treated rattle sounds from bigger, warmer snakes as a greater threat,

and we're less likely to approach the playback speaker. It almost feels like something out of sun Zoo, right, you know, kind of like provoke and observe, get your enemy to reveal their strength through the sound of their rattle, and you judge how to engage, and they can tell from

that sound how strong their enemy is. It also, this also is is very reminiscent of that stalking behavior we previously discussed, you know, just sort of be there, be a little obnoxious in your presence, and then use that intel to your advantage. Yeah, but some of their other tactics the same, squirrel It just gets brilliant. So I want to talk about rattlesnake baths. Oh yeah, I think I read about this in Good magazine. This is a

This is for for for for your skin tone. Right right, you melt fifty rattlesnakes and get into the bathtub with your special pumice stone. No, no, no, no no, this this is for squirrels, not for humans. So rattlesnakes generally have poor vision, and one of the key senses they rely on for hunting is scent. So snakes can smell with their nostrils, but they have a much more keen sense of smell not through their nostrils, but through a region in the roof of their mouth called the Jacobson's organs.

This is where the flicking to h and connects with the roof of their mouth exactly right. So when you see a snake flicking out its forked tongue, that snake is sniffing the air. The flicks of the tongue collect information which are volatile scent carrying compounds in the air, and they bring those compounds back into the mouth to mix with oral fluids and then get taken through ducts in the roof of the mouth to the Jacobson's organ.

Side note, there's apparently some amount of controversy about whether humans have a functioning Jacobson's organ, Like, it looks like we've got some kind of tiny analogous structure, probably nonfunctional, and that might be worth a deeper look someday. Um. But anyway, Snakes use this smelling apparatus to locate prey by smell. So if you're a squirrel that this snake would like to eat, what do you do? You can run, you can hide, but you can't stop emitting volatile compounds.

You're always going to be putting up these molecules that this relentless predator can tract through the air. So the California ground squirrel has this wonderful adapted behavior. It takes a snake bath. Snakes periodically have to shed their skin in order to allow their bodies to grow and remove external parasites. And when one of these squirrels comes across a snakeskin discarded in the on the ground, it begins

to set to work. So first it takes bites out of the skin and choose it up into a snakeskin mushball in its mouth, and then it spits the mushball out on itself and smears the snakeskin poultice around in its fur. And then it keeps doing this until it smells more of snake than of squirrel. And these animals have also been seen smearing snakeskin mush under their young

to protect them as well. If a snakeskin is not available, sometimes they will pick up the snake scent by rubbing themselves in the soil from places where rattlesnakes have been resting, and apparently the North American rock squirrel has been observed doing the same thing. Clever girl. One last crazy anti snake adaptation. In addition to their sense of smell, rattlesnakes use heat sensing organs right called pit organs in their faces. Is to hunt down by detecting body warmth. So the

snake lives in a world of smell and heat. And if the squirrels have a smell based defense, do they also have a heat based defense. You bet you that this is true. Researchers, including Airin s Runda's, discovered in the two thousands that California ground squirrels threatened by rattlesnakes turn their tails into this weird kind of beacon of

heat energy. It's a whipping heat element. So Rundas claimed at an animal behavior conference in Mexico in two thousand four that the squirrels apparently do this by getting the fur on their tails to stand straight up, which allows more of the underlying skin to be exposed to the air and dilates the blood vessels under the skin, causing the skin to broadcast more heat in the form of infrared radiation. And further research on these initial observations involved

creating a robot squirrel. Did you ever think science would take us here, Robert robot squirrel? No, I have to have to say, it seems like they're you would expect robot mice, you would expect robot snake. And I've seen both of these, but I've never contemplated the robot squirrel. Well, I like the swimming robots. You know that there are a lot of good robot animals out there, But I've never heard of robot squirrel before this, but sometimes you

gotta tweak different independent variables. Sometimes you need to make a robot squirrel. So that's what they did. Uh. And I want to mention one study from Proceedings of the National Academy of Sciences in two thousand seven. This is rund Us owings Yoshi Chin and Giannini called ground squirrels

use infrared signal to deter rattle snake predation. So in animal trials, Rundus and co authors found that quote, California ground squirrels add an infrared component to their snake directed tail flagging signals when confronting infrared sensitive rattle snakes, but tail but tail flag without augmenting infrared emission when confronting infrared insensitive gopher snakes. So this means they can tell

the difference between different kinds of potential predators. Uh, the kind that that since heat got a hot tail and the kind that do not sense heat got a cold tail. And here's where the robot squirrel comes in. They built a robot squirrel that could whip its tail with or without tail heating at the same time. And what they found was quote, when the infrared component was added to

the tail flagging display of the Robotics Squirrels. Rattlesnakes exhibited a greater shift from predatory to defensive behavior than during controlled trials in which tail flagging included no infrared component. So when you go at a heat sensitive snake with a hot tail wagging around in the air for some reason,

the snake is more likely to back down. And so to answer that question, research with rattlers in with this robot which is of course known as the robo squirrel that's been ongoing more recently, but there there is video of the robot squirrel online. We've referred you to several video type searches. You can look up robo squirrel and it's worth seeing. It's it's pretty good. It's like on a rack, so it'll like rack forward towards the snake

and then its tail will whip back and forth. And if they hate it up, the rattler just kind of sits there. But if they don't, when the squirrel tries to retreat, the snake will lunge at it. Yes, do check out that video if you get a chance. I gotta say I am in general quite impressed with the

California ground squirrel. It's a machine, yes, it the non robot version as a machine, it is um and generally here at the end of this episode, I I am just really impressed by the abilities and the viciousness that we find in the Kingdom of the scugs, the these these the squirrels, these tree rats that we we've just so often taken uh for granted. You know, one thing I wanted to return to, if you don't mind, is I've been shocked by the behavior of squirrels that we

learned about in this episode. But I'm also shocked by Benjamin Franklin because his his elegy for for Mungo the scug uh is a very anti freedom and prosecurity. Did you notice that vein in it? I didn't really pick up on that, now, I guess I was just more focused on the cage squirrel without really thinking about the

political implications. Well, he says again, learn hints ye who blindly wish more liberty, whether subjects, sons, squirrels, or daughters, that apparent restraint maybe real protection, yielding peace plenty and security. That seems to really go against that Benjamin Franklin quote where he says those who would give up essential liberty to purchase a little temporary safety. Deserve neither liberty nor safety. That's one of the you know, one of those great

American pro freedom quotes. But I looked that up to see what's the deal with did he really mean that? Weirdly enough, unfortunately, that's one of those quotes where the warped out of context misunderstanding of the quote is actually a lot more profound and good than the original meaning. The original meaning of that quote hinges a lot more on the idea of quote a little temporary safety. He was like writing against people who were putting in place

sort of temporary inadequate security measures. Yeah. Interesting, I like the misunderstood version better. Yeah. Yeah, I think it is a more pleasant thought for sure. All right, Well, there you have it, uh, first part of our two part exploration of just general squirrel weirdness and savagery. We hope you've enjoyed this introduction reintroduction to the world of the scugs, and I hope that you will tune in next time

as we continue. Let us leave you with one more thought at the end, though, do not take this as license to mistreat squirrels just because they may carry in. Just because they may want to vole brain now and then, that doesn't make them the bad guys of the animal kingdom. We encourage you instead to look on them with all and wonder. Yeah. I think actually the squirrels are more entertaining to me now because I know what they're really about.

I know what they're up to. All right, Well, you can check out all the other episodes of Stuff to Blow Your Mind at Stuff to Blow your Mind dot com. That is the mothership. That is where you will find uh all those epi sodes. You'll find links out to our very social media accounts at the top of the page. You'll also find our store button. Yes, you can go

to our store. You can buy t shirts, stickers, coffee mugs, tope bags, you name it, featuring our brand new, swanky logo, a few variations of that logo, some without any text at all. You can do what I like to do and just have some sort of perplexing glyph, uh you know, on your your sticker or your your shirt, and just let other people ask you about it or figure it out on their own. And we're gonna be adding more

designs as as the days go on. We just recently added one that was a reference to a movie Robert and I talked about wishing existed in our black Holes episode The Sphere Catastrophe. Yes, you're sort of what nineteen would you say, sixties fifties? Sixties? Yeah, nineteen sixties horror movie about a black hole, French horror movie. Well, now you can see what that poster might look like on this uh this T shirt or sticker or note bag or bad a throw pillow, you you name it, you

can it on anything. There's also a bicameral mind shirt on there that some folks are really digging. March up, yeah, merch up, and it's a great way to support the show. Another way to support the show without spending a dime is to simply rate and review us wherever you have the ability to do so. So true, huge thanks as always to our wonderful audio producers Alex Williams and try Harrison.

If you would like to get in touch with us to let us know feedback on this episode or any other, or to suggest a topic for the future, or just to say hi, you can email us at blow the Mind at how stuff works dot com for more on this and thousands of other topics is it, how stuff works? Dot com, we git, dator report, Propa