Squirrels, Part 1: The Bloody Beast

You might think you know squirrels, but what do you REALLY know about these woodland tree rodents? In this special two-part episode of Stuff to Blow Your Mind, Robert Lamb and Joe McCormick discuss their appetite for meat, their alleged acts of savagery and various other facts that will make you reconsider the skugg and respect its kingdom. Up first, let’s talk about their bloody diet...

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Episode Transcript

Speaker 1 (00:03):
Welcome to Stuff to Blow your Mind from how Stuff
Works 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

(00:23):
American founding icon Benjamin Franklin's Gonna Be the Turkey had
that whole song about it right in 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

(00:45):
and U. Ben Franklin was played by a local attorney
named Ray Freely. Ray Freely y 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 Timmy Jefferson, Timmy Timmy. Yeah, he is kind

(01:06):
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 was had pretending to write in
Wada paper. Okay, oh, sorry, we got sidetracked here, but
there is a song in there where Benjamin Franklin he
suggests that the U. S National bird should not be
the should not be the eagle, and should not be
the dove, but should be the turkey because it is

(01:28):
a most majestic bird. And I found no evidence that
Franklin actually suggested that the national birds should be the turkey.
But Franklin was all about some turkeys, especially was all
about killing turkeys, and especially it was all about killing
turkeys with his favorite technological toys, the ladon jar. Uh.
We we've talked before in our episodes about the early
days of electricity about that that barbecue Franklin hosted where

(01:51):
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

(02:12):
our Thanksgiving tradition? Should a big, 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. No pardon for you,
all right? So if the if the turkey wasn't his
favorite animal, uh what pray tell? Was it? Well? Who

(02:33):
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

(02:54):
pet squirrel named Mungo that he kept in a cage.
They got killed by a dog named Ranger. 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

(03:15):
and seen much of the world. In other words, I
I put it, put him in a cage, and carried
him on a 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. It is like an elegy for poor Mungo.
I wonder if we should do a reading of this
poem for Mango. What do you think, Well, I don't

(03:36):
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 hatst not to fear from his piercing talents, nor
from the murdering gun of the thoughtless sportsman, Safe in

(03:59):
his why aired castle, Grimalkin never could annoy thee Grimalkin,
of course, is the which is familiar the cat from Macbeth.
I think 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

(04:23):
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.

(04:43):
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. But you didn't
know that one either. I didn't, But you know, I

(05:04):
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 obvious fill our backyards in our lives. Robert,
I am so excited to talk about squirrels for two

(05:26):
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,

(05:51):
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 environment. 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

(06:11):
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 my family. We like to when we're having

(06:32):
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

(06:53):
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 I 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

(07:14):
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 notice them,
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. Chipmunk is I think,

(07:36):
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 one over body scurring

(07:59):
creatures and their 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 tours
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

(08:21):
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

(08:42):
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 are. They are tenacious, and you should
and you feed them at your peril, 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

(09:04):
it was ranting a little bit. I no, 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,

(09:24):
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

(09:46):
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 bidding. That's right,
they have the height advantage. The squirrels are the wizards
up in their ivory towers, and the rats are the peasants,
the 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,

(10:08):
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 nosis.

(10:28):
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

(10:52):
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, and the likely
extinct cream colored giant squirrel. Many additional varieties roamed in
prehistoric times. Uh and plus this family also includes groundhogs

(11:13):
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

(11:34):
them where they go. So humans introduced squirrels to Australia,
and now they're everywhere on Earth except 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

(11:55):
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

(12:16):
is that squirrels are not, in fact strictly herbivores. Some
not very strictly at all. That's right, and uh and
I 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

(12:37):
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 feel up
this little cup, and you know, squirrel would come and

(12:58):
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

(13:21):
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 I don't know, it's it's like that's
like the cracked corn of the animal kingdom. Right, Yeah,

(13:42):
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

(14:03):
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

(14:24):
in them, not just in their bodies like they are.
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.

(14:45):
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
s world disembowels the deer and eats the contents of
the stomach as well as the heart and the liver.

(15:06):
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 squirrels supposed alleged squirrel slaughtered deer.
And then they also attest to the hearts and livers

(15:28):
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

(15:51):
in your logic here, as opposed to saying, well, it
was probably some sort of scavenger that came and did that. No,
it was probably a ferocious and strategically ishous 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

(16:13):
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

(16:35):
me a lot of 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 an autopsy in the middle of a
cow field, or squirrels or hunting impacts. But how much

(16:56):
could you really learn in the middle of a cow field.
I don't know. It's it's like 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 will get back to, and that is that squirrels
do seem to hunt some of the time. Well, we

(17:19):
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

(17:42):
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 to Yanov said

(18:06):
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, 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,

(18:30):
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 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

(18:53):
I also am skeptical of that. I'd wonder though, I mean,
maybe if the dog is, like, I don't know, sick
and all ready almost dead, that might be a different
kind of thing. I find it hard to believe that
like 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

(19:13):
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

(19:34):
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

(19:56):
previous research by other investigators. During his excavations at the
old village site of Kakuliak, located 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

(20:17):
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

(20:37):
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 thank you,

(20:58):
thank 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

(21:21):
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 trickin 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. But

(21:44):
you're not getting trickin 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, m what's going on here? It's clear what's
going on. So the ground squirrel, that with the ground squirrel,

(22:05):
they say, although primarily herbivorous S 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 Talqitna 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

(22:29):
would of course be exposed to infection because the dogs
and the foxes can get the 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 do
the red squirrels get them quote we have observed red
squirrels feeding upon the flesh of the Snowshoe, hair, carrion,

(22:51):
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

(23:14):
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,

(23:35):
they'll definitely eat that. But he's certainly to eat to say,
a worm or a snail for 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,

(23:56):
but it's out there. It's it's obtainable if anyone else
wants to to read it in full. Uh. So, he
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 little

(24:16):
tree dogs or or some sort of a tree cat,
you know. Uh, it is, so 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

(24:38):
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. You know,
a lot of these reports come down to trying to

(25:00):
figure out, you know, were they just scavenging meat, were
they just eating something that was already dead, or did
they or was it an opportunistic attack, or they in
fact stalking something? How did you get those voles 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,

(25:27):
fish bowls, ducks, wild turkeys bringing it all back home. Yeah, turtles, crabs,
and salaman This is too good. 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

(25:48):
phosphorus from the bones, but there were there There were
also reports of them eating bone and antler or ignoring
meat in favor of joints. Joints, so like they're trying
to get like cardial edge and ligaments and stuff. Interesting. Yeah,
he's 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

(26:12):
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

(26:34):
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,
viscera and the flesh of the head. What squirrels eating brains? Yes,

(26:57):
this can't be real. It is real. It is very real. Brains.
So we seem to see far 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,

(27:21):
and in these cases too, we see these same squirrels
turning to predation when their cage, when they no longer
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

(27:45):
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 bird words that live in an urban environment. Say,
like the example of um, the birds that learned how

(28:05):
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,

(28:26):
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 in 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

(28:51):
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 squirrels, 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,

(29:13):
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. 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

(29:33):
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,

(29:55):
carrion certainly packs the nutrients. Uh, and it's it's also
not equable 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

(30:15):
the best parts of the you know, say that the
dead uh, 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

(30:36):
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

(30:59):
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 cannibalize carrying 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

(31:19):
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

(31:41):
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. So they are
still opportunistic, not fundamental predators. Okay, so he's going, so

(32:05):
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

(32:27):
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 a 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 unhearu the hypothesis

(32:50):
that I am about to share with you, lad Onmi Robert,
all right, 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,

(33:13):
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

(33:33):
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. So this would not
be something we're saying that the squirrels are doing consciously,

(33:53):
But they've somehow instinctually learned to like to to sort
of feign at acts 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 they but they are doing it in

(34:14):
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,

(34:35):
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

(34:56):
be able to see squirrels the same after this episode.
Now the other hand, we don't like to demonize any
type of animal here, and of course predation is part
of nature. 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 have

(35:19):
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 dogs. Yeah,
it's it's gonna be fine. Yeah, you're not really in
danger from the squirrels. But I do have to say.

(35:40):
It's 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 work.

(36:00):
That's all I'm saying. Well, you could I don't want
to make you feel bad. You could also be artificially
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

(36:21):
around on this question, and there is a two thousand
fourteen horror movie called Squirrels. But it sounds 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 The
better horror movie mascot for this episode would probably be uh,
tromy the radioactive squirrel from Class of Newcomb High to

(36:46):
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 radio active giant squirrel rampaging
and knocking over cooling towers. It it is worth checking out.

(37:06):
But you'll definitely want to see Class of Newcomb High
one first, you know, for you know, it's compurity and
continuity 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

(37:27):
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 squirrels Tammy Ascurus hudsonicus, like other squirrels, they

(37:52):
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

(38:12):
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 caches
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

(38:33):
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.

(38:54):
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 con right. You can't bank
on tourists. You can't bank on vole brains. You might
not be able 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

(39:14):
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

(39:35):
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

(39:56):
videos seem to show squirrels looking trees other than maple's.
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

(40:18):
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

(40:38):
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

(40:59):
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

(41:20):
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

(41:41):
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 of all, a greater natural resistance to

(42:02):
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

(42:24):
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

(42:45):
a snake and the squirrel is the attacker keeps biting
the snake on the spine. 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

(43:06):
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

(43:28):
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 Rattle Snakes and
rattling sounds the roles of sex, reproductive parody, and offspring
age and Assessment and decision Making Rules from two thousand

(43:48):
three UH Specifically, they found that quote larger, warmer snakes
are more dangerous than smaller, colder snakes. H 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 snake
is warmer than the other one. Apparently, what the squirrels
do is they listen to the rattle. So if you

(44:11):
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,

(44:34):
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

(44:54):
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. You 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

(45:15):
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,

(45:38):
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

(45:59):
a region in the roof of their mouth called the
Jacobson's organ. This is where the flicking tongue then connects
with the roof of their mouth. Yeah, 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

(46:20):
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, that might be worth a deeper look someday. Um.

(46:41):
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

(47:04):
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 snake skin 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

(47:26):
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

(47:49):
have been resting, and apparently the North American rock squirrel
has been observed doing the same thing. 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 to hunt down by detecting body warmth. So
the snake lives in a world of smell and heat.

(48:10):
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 Rundas, discovered
in the two thousands that California ground squirrels threatened by
rattle snakes turn their tails into this weird kind of
beacon of heat energy. It's a whipping heat element. So

(48:30):
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

(48:53):
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 snakes, and I've
seen both of these, but I've never contemplated the robot squirrel. Well,
I I like the swimming robots. You know that there
are a lot of good robot animals out there, but

(49:13):
I'd 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 Rundus owings Yoshi Chin and Giannini called ground squirrels
use infrared signal to deter rattle snake predation. So in

(49:36):
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

(49:57):
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 since 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

(50:19):
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

(50:41):
to answer that question, research with rattlers and 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 act, so it'll like rack forward towards the snake

(51:03):
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's the non
robot version is a machine. It is um and generally

(51:26):
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

(51:46):
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 very ant high freedom and pro security.
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

(52:10):
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.

(52:34):
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

(52:56):
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

(53:19):
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,

(53:42):
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 com
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(54:02):
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(54:44):
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