Nature's Apothecary: Monarchs, Milkweed, and the Art of Self-Medication with Dr. Jaap de Roode

Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Andrew MacIntosh (00:00):
After the tune , a conversation with Dr Yap
Darud of Emory University on themonarchs of the insect world
and the meditative behaviorsthat help them fight disease.
Conservation, behavior,primatology, typically primates,
become the monkey.

(00:34):
Hey everyone and welcome to thePrimateCast.
I'm your host, andrew McIntosh,now of the Wilder Institute
Calgary Zoo, and for thispodcast, it's my job to chat
with experts in primatology,wildlife science and beyond and
share their stories with you.
Today, we're definitely goingbeyond, as we'll be exploring
the magical world of monarchbutterflies and the behaviors

(00:54):
that animals perform to keepthemselves healthy.
Yap DeRude is Samuel CandlerDobbs Professor of Biology at
Emory University, and he's alsothe author of the forthcoming
book Doctors by Nature how Ants,apes and Other Animals Heal
Themselves, due out fromPrinceton University Press on
March 4th.
Now, in spring of 2023, whiledoing some research for his book

(01:17):
, yap was in Japan visiting MikeHuffman, my close friend and
mentor and one of the world'sforemost experts in animal
medicative behavior.
The three of us took theopportunity to sit down together
in the studio and record awonderful conversation about
monarch butterflies, the worldof parasites and how their clash
has led to one of the mostastounding discoveries in animal
science that these beautifulinsects, and pretty much any

(01:39):
other species that we've everbothered to look at, are able to
medicate to fight offinfectious disease.
Yap paints a vivid picture ofthis timeless struggle between
host and any other species thatwe've ever bothered to look at
are able to medicate to fightoff infectious disease.
Yap paints a vivid picture ofthis timeless struggle between
host and parasite.
He's a wonderful sciencecommunicator and has a knack for
making tough ideas accessiblewhile maintaining rigorous
scientific rhetoric throughout.
Now, since Mike made hisdiscovery of self-medicating

(02:00):
chimpanzees back in the late1980s the field of animal
self-medication.
Self-medicating chimpanzees backin the late 1980s the field of
animal self-medication, or justanimal medication, since they
can sometimes medicate not justthemselves but others, as Yap
likes to remind us.
This field has exploded toinclude a dizzying array of
species, and that's where Yapand his monarchs come in and why
you'll want to stick aroundwith us for this conversation.
So let's get right into it.

(02:22):
Here's my conversation, helpedalong by a healthy dose of sage
wisdom and bad puns from MikeHuffman, with Dr Yap Darude.
Yap Darude, thanks for joiningthe Primatecast, and let me
start by asking you what you'redoing here in Japan.

Jaap de Roode (02:36):
I am here to visit Mike Huffman and to talk
about all things animalself-medication.
Mike and I have beencorresponding for a while and a
lot of my own work, which is onbutterflies and medication,
really is based on thegroundbreaking studies that Mike
did on chimpanzees back in theday, and currently I'm also
writing a popular science bookon the topic, and so really

(02:59):
benefiting from my conversationswith Mike, who's really the
expert in the field.

Cool.
So we're definitely going toget to a lot of the
self-medication in animals a bitlater on.
I want to maybe back up alittle bit, if we can, and just
maybe we can talk about how yougot to where you are.
So now you're at EmoryUniversity, mainly working with
butterflies, and you have agreenhouse that you do a lot of
cool experiments with, whichwe'll get to as well.

(03:23):
But what was the kind ofpathway for you to get here and
get interested inself-medication?
What is your background?

So my background is really in parasitology.
I was studying populationbiology in the Netherlands and
from there deciding to do a PhD,choosing between a lot of
different topics.
I was at a conference aboutmolecular ecology and there was
one really inspiring talk onparasites and the professor was

(03:50):
talking about competitionbetween different strains of
malaria parasites within thebloodstream of mice, and to me
that was really interestingbecause I hadn't really thought
about parasites sharing a hostas an ecosystem where they
compete.
Like animals in the savannahcompete for grass or trees,
these parasites are competingfor red blood cells.
So I spoke to him and thenstarted doing an internship in

(04:14):
his lab for seven months andliked it so much that I then did
a phd in his lab after that toreally study these malaria
parasites in mice.

So around that time Mike and I maybe we can
Mike can come in as well laterbut have been involved in groups
in Japan working in malaria aswell and malaria that can be
shared, for example, betweenhuman and non-human primates.
But at the time when youstarted I'm wondering how much
consideration was given to theecology of malaria parasitism.

(04:45):
It seems like that obviouslywork comes out of kind of the
medical field mainly, but yourtake, right from the beginning
it sounds like, was more theecology.

Yeah, so ecology and evolution were really my
background and so I reallylooked at the ecology within the
host, right?
So really seeing the host as anecosystem in which you have
competition for resources, inwhich you have shared enemies,
which is the immune system, andso you can really think of this
as different animals in a in aforest that compete for grass or

(05:15):
trees and are attacked bypredators, right and so, which
is different from the kind ofecology when you think about
malaria parasites that may jumpfrom non-human species to humans
, right, that's a completelydifferent aspect of ecology,
where you look at the ecosystemwhich have different hosts,
where parasites jump betweenthem, and that certainly was

(05:36):
that's that's been a field Ithink that has grown a lot over
the last few decades veryinteresting, but my interests
originally were really aboutthinking about ecology within
the host yeah, I remember in themust be I don't know if it was
the late 1980s or 90s there wasthis movie that came out,
starring dennis quaid and martinshort, called uh, inner space,
and that's right.

I remember thinking, yeah, there's a lot of
, there's a lot of ecolite.
There was kind of a predator inthere.
It was like this kind of crazyguy in a suit that was trying to
, you know, destroy their shipand right, but uh oh yeah, that
was a great, great film.
Yeah, it's a good fun, right?
Yeah, but so you have thesemice, uh, during your studies
there, which are in a lab, sobasically nobody would think
about those laboratory mice asbeing in any kind of an

(06:17):
interesting ecosystem settingbut what's?
happening within them.
Um, is is obviously ondifferent scales, but so what?
What were the kind of, whatwere the kind of major insights
that you found?
And how did you kind of come tothose thinking about mice as
ecosystems?

Yes, I was really interested in two major
questions.
One of them was to understandwhy parasites are virulent.
So when we think about how wedefine, parasites are organisms
that do damage, may causedisease or kill their hosts, but
they don't give any benefits.
But oftentimes people don'treally ask why they do that,
right?
And when you ask that question,oftentimes the answer is well,

(06:54):
give them enough time andthey'll be benign, right.
So oftentimes you may think ofa parasite jumping between
species that arrives in a newspecies and the kind of
conventional wisdom is thatbecause they depend on those
hosts, they're going to be nice,they're not going to do damage
or kill them.
But from an evolutionary pointof view that doesn't make any
sense because everything isabout fitness and for parasites

(07:16):
that means getting as muchtransmission as you can.
You know, go, you're in thishost, you need to get to another
host.
How do you do that?
How do you optimize that?
In this host you need to get toanother host.
How do you do that?
How do you optimize that?
And so theory at the time wasthat virulence evolves.
So the damage to the hostevolves because it's an
unavoidable product ofmaximizing the transmission
between hosts and one of thefactors that could drive that

(07:39):
virulence higher is competitionwithin hosts.
So because then you have yetanother thing to worry about.
If you think from theperspective of a parasite, it's
not just about how you maximizeyour transmission, but how do
you maximize your transmissionmore than your competitors?
And so then you get selectionfor faster growth rates, higher
transmission, and therefore,because you grow faster, you

(08:00):
produce more offspring, you killmore red blood cells, you do
more damage, so you cause moredisease.
After you produce moreoffspring, you kill more red
blood cells, you do more damage,so you cause more disease.
So that was the theory that Iwas testing using the mice and
the parasites, and that involvedboth mice and it involved
mosquitoes as well.
And then the other thing that Iwas interested in was drug
resistance and really thinkingabout drug-resistant parasites.

(08:20):
They first evolve throughmutations, right, you get
mutations.
That gives drug resistance tothis parasite, and then the
question is what will happen?
So it happens in a host, butthen it's competing with
parasites that are not resistant.
So how does that competitionshape that evolution and the
spread of drug resistance?
And then we found that thesensitive parasites can actually

(08:42):
suppress the resistantparasites, so that competition
can also in some ways bebeneficial.

Yeah, so can you.
I mean just to maybe kind ofbreak it down.
It doesn't have to be in yoursystem, in any kind of system.
When we think about because thatis a very common idea that
parasites should evolve tobecome less fearful, to kind of
support their existence and andand, in a way, evade the immune
system, I suppose, um, but Ithink I've also uh, you know,

(09:11):
this is kind of our field aswell and come across various
examples maybe of how it reallydepends on the system that
you're looking at as well.
Absolutely so do you have anygood examples of, maybe for
listeners, if you think abouthow transmission can drive
parasites to be more virulentwhat might be an example of that
.

So I think some really obvious examples are
parasites that need their hoststo die right To get transmission
, and so there are a lot ofparasites that have multiple
host species within their lifecycle.
And so, for example, when youthink about parasites that
infect snails and the snailshave to be eaten by birds so
they can make it to the birds,and obviously making sure that

(09:50):
snail gets eaten is is importantfor the parasite, but that
means that snail is gone right.
So I think that's a really goodexample you also think about
maybe something closer to homefor people is rabies virus.
You think about rab.
How does rabies spread fromhost to host?
It is really through this kindof aggression where an infected
individual starts biting anotherindividual and in order to get

(10:14):
that done, the parasite I referto viruses as parasites as well
is that that virus needs toinfect the brain and really
causing a lot of inflammationand a lot of disease.
But really with the, you knowthe function of changing the
behavior, so there's moreregression, there's more
production of saliva andtherefore there's a higher

(10:35):
chance of biting someone elseand getting transmitted, and you
know, but all of that causes somuch damage that it also kills
the host in the process.

Michael Huffman (10:45):
What about the case of natural reservoirs?
I'm thinking of Ebola, forexample.
It can run through a populationof animals really quickly, or
humans and decimate them, but itgets along quite well with the
reservoir species or the carrierthat's not affected.
The reservoir species or thecarrier that's not affected how

(11:07):
does that deal with the ideathat parasites should be
compatible with their host andshouldn't be in the argument
that you just gave?

Yeah, I think it really depends on the exact
combination of the host and theparasite how much virulence
there is going to be, and soreservoir species often harbor
parasites and viruses with alonger co-evolved relationship,
and in some cases that canreally lead to a more benign
relationship.
And then, yes, you often seethat the species will jump, a

(11:39):
virus or another parasite willjump to humans or another animal
and cause a lot more damage,and so I think that's where that
conventional wisdom came from.
We should often see that, andyou can even see it with the
COVID-19 pandemic right, we haveseen that the virus was a lot
more virulent to start with, andit's become less virulent over

(12:01):
time.
At least you know, that's mostof what the science says.
Of course there's also morevaccination, which reduces the
virulence too, but you often seethat viruses or other parasites
evolve less resistance.
But it doesn't have to be thatway.
So it really depends on how theparasites maximize their
transmission, and that can meanthat they're going to be very
non-virulent or they can behighly virulent.

Yeah.
So in the case of Ebola, whereis it happiest?
In a host that it doesn't causeproblems, or in humans or
gorillas, where it runs througha population and it disappears?

I would think it's probably happiest if
viruses can be happy at all.
You know I'd say it's happiestin a population where, where you
may not even notice, it's therebecause it's it.
If it, if it can infect moreand more individuals in a
population, it has a higherfitness and oftentimes what you
see with viruses like ebola isthat they burn themselves out

(12:57):
right, they jump to humans andtheir mortality rates can be so
high that they essentially killbefore they can transmit.

Yeah, I don't think we in the primate cast are
going to get into the questionof whether viruses will be happy
or unhappy in their currentsituations.
But you know, thinking aboutthe ecosystems, you know we've
also looked at throughliterature search in primates.
You know, looked at through aliterature search in primates.

(13:28):
You know, as certain parasiteshave longer and longer kind of
co-evolutionary histories withtheir hosts, those kind of
specializations can also affecthow the host will interact with
other agents and parasiticorganisms in the environment,
and we've noticed that,according to the published
literature, on a global scale,the primates that are more
threatened tend to be those thathave fewer parasites or less
prevalent parasite infections.

(13:49):
But it's different depending onwhether you think of host
specialists, parasites orgeneralists.
And the scary thing there isthat, you know, as host
populations are in decline,maybe specialist parasite
prevalence is on the decline aswell, because they depend so
much on those single hosts.
It's really the generalists,you know, the ones that can hop
from species to species, thatmay cause by far the most damage

(14:10):
, and then that also wouldinfluence the virulence argument
.

Yeah, yeah.
I also think the argument issomewhat driven by
misunderstanding what parasitesand viruses do in wild
populations.
It's not that long ago thatpeople thought that malaria
parasites or SIV viruses didn'tcause any disease in the apes
the wild apes, right and thenhumans get it and we get sick.

(14:35):
But you know, when you actuallystudy them, you find, yes,
there are all sorts of diseasesymptoms.
So I think that's another thing.
So it's easy to say well, youknow, they're just infecting
those chimpanzees or gorillasand they're totally fine.
And now we get them, we getsick.
And I think that's just amisunderstanding.
That hasn't been studiedproperly until recently.

Yeah, super interesting the more we learn
right about how some parasiteshave the capacity to modify the
behavior of their hosts in a waythat may lead to their
destruction, to complete thelife cycle of those parasites
that have complex life cyclesand involve multiple host

(15:14):
species.
And then this also kind ofinvokes the question of the
general relationships that wesee between parasites and their
hosts.
And I think this we can usethis as a kind of segue into the
self-medication, because you'vewritten about self-medication
as, or questioningself-medication as, parasite
manipulation or host defense,and so maybe before we get into

(15:39):
the host defense side of it,let's talk a little bit about
parasite manipulation, and wecan also use that to maybe
transfer into butterflies.
Yeah, so can you expand alittle bit on what you've seen
in your work and how certainparasites may be linked to
manipulation of host behavior?

Yeah, so maybe I can talk a little bit about how
I got to butterflies Great andthen start thinking about how I
started approaching that.
But I mentioned that I studiedmalaria parasites in mice and,
as you pointed out, they weremice in the laboratory and you
know.
So you can think of it as anecosystem within.
But a mouse in a cage in abasement of a scientific

(16:19):
building doesn't, you know,shout ecosystem or nature at you
, right.
So, and so I actually,throughout my PhD, I was kind of
frustrated with the artificialnature of that research and I
wanted to get to study a systemthat is a natural system.
I also wanted to study a systemthat was a little bit simpler,

(16:40):
that had a less complex lifecycle.
Malaria parasites have themammal as a host and the
mosquitoes, and they have to getthrough both of them, and I
wanted to have a parasite thatjust has one host makes it makes
it easier to study.
I wanted to be able to study itin the wild as well as in the
lab, and I found parasites ofmonarch butterflies.
They're protozoan parasites,actually not that distantly

(17:02):
related from malaria parasitesand it.
When I first learned about them, I was really wowed by it
because I thought this is reallyexciting.
These are parasites in in abutterfly species that I knew
from a spectacular migrationthey undertake every year, but I
had never heard of theseparasites before and I thought,
wow, this is a really goodopportunity to start thinking

(17:24):
about these parasites in a wildpopulation yeah and um, and you
know and it's interesting toobecause I started with the
question of what makes parasitesvirulent so I took that
question to the butterflies andso that's really the first
project I did trying tounderstand if that selection for
transmission can select forvirulence and I found that with

(17:45):
a lot of experiments I didtrying to understand if that
selection for transmission canselect for virulence and I found
that with a lot of experimentsI did, and then the idea of
behavior and medication reallycame later and that was really
when I started thinking aboutthe relationship between the
host and the parasite and thehost plants that the monarchs
use, because monarchs arebutterflies, so the adult

(18:05):
butterflies can drink nectarfrom any flower.
The caterpillars are specializedand they're specialized on
milkweeds and from theliterature we knew that the
milkweeds have really excitingchemicals called cardenolides.
They're toxins.
If we have too many of them wedie.
In the right dose we can usethem as heart medicine.
But the monarch butterflies candeal with these toxins very

(18:26):
easily and the literature alsotold us that the monarchs can
use the toxins to protectthemselves against predators and
in fact they advertise theirtoxicity.
So what they do is they feed onthe milkweeds, take the toxins
out of the milkweeds, put it intheir own tissue and then
advertise using their black andwhite and orange to predators

(18:46):
that they're bad tasting I Iwanted to ask you actually, um
when?

so the?
That's a nice an example ofapple semitism you have this
warning coloration in themonarch butterflies and they are
toxic to potential predators.
But I was curious in thecontext of signaling that
toxicity, do you notice whetherthe caterpillars that intake
more or less of the toxin fromthe plant actually have

(19:16):
variation in the colorationsthat they have?
So is there a correlationbetween the degree of toxicity,
for example, in the caterpillar,and then the coloration of the
adult butterfly?

there is some variation in the coloration, but
as far as I know and as far aswe have looked at it, there is
very little effect of theparticular toxicity levels
driving that color variation.

so I think it's, in some ways, the color
variation is very much justthose specific colors that tell
predators to stay away, becausenormally when we think of, for
example, signaling forreproductive purposes if you
think of birds, there's thishandicap principle, which has
been challenged, but in any casethe animals that are in worse

(20:03):
physical condition don't seem toproduce the same kind of
strength of signal.
So I was just curious if thatwas also true for these monarchs
.

No, I don't think so, so are there
butterflies that don't havethose signals, that are also
ingesting toxic plants?
Is there a system where thereis no link between what the
insect is eating?

I think pretty much all the butterflies that
sequester toxins from theirplants are advertising that
toxicity.

And, overall, what percent of the species
sequestered do you know?

That's a great question.

I don't know Sorry.

Someone out there can google it and write
into the primate cast they're,you know, as an aside, the
viceroy butterfly, which I'msure you're familiar with.

Oh, it's a mimic of the monarch but it is not
toxic so okay, so it actually is, and so yeah, it used to be
believed that the viceroy mimicsthe, the monarch, but the
viceroy, which, as caterpillars,feed on willow trees, they're
also toxic.
So it's actually a interestingmalarian mimicry where both are
model and both mimic the other.

(21:10):
Um that I will say the mimicryis extremely successful because
if you google a picture of amonarch on the internet, a lot
of the pictures you get areviceroys and I I have seen so
many articles published inpopular science magazines and
also an advertisement campaignswhere people instead of a

(21:31):
monarch show a viceroys.
Always there.
I've been actually to mexico,to the overwintering sites, and
they have a lot of littlesouvenir shops.
When you go up to theoverwintering sites, where
there's literally tens ofmillions of monarchs, they sell
t-shirts made in china and oneyear about half of the t-shirts
show vice rose, not monarchsyeah, buyer, beware right I will

(21:55):
say one more thing about theorange coloration, because I
think when you started thispodcast earlier, you said
we're're going to talk aboutmonarchs, but not the ones with
the little crowns.
Now, the name monarch actuallycomes from the Dutch monarch, so
the Dutch royal family.
I'm from the Netherlands myself, so I find this a fun fact.
But the Dutch royal familyactually comes from France, and

(22:16):
so we have William of Orange,the founding father of the
Netherlands, and so their coloris orange, and so when you see
our soccer team play, it's inthe orange color.
So the story is that when theDutch made it to the Americas
and saw this big, majestic,beautiful butterfly, that's
where the monarch name comesfrom.

Great, I had no idea where the name came from
.
I thought you were going totell me they do wear little
crowns when they're flyingaround, they don't?
Only migrating butterfliesmaybe.
That would create too muchresistance in the air.
We've diversed a little bitfrom the main, but so yeah.
So, coming back to this idea ofand I want to talk more about

(22:59):
monarchs, maybe afterwards.
Since we were talking aboutinfectious disease and
parasitism and behavior.
I think it's a good place tokind of transition into
self-medication and to do that Ijust want to read.
So you published a paper in2013 about self-medication in
animals.
This was a review, and thefirst line in the abstract reads

(23:20):
the concept of anti-parasiteself-medication in animals
typically invokes images seekingout sorryokes, images of
chimpanzees seeking outmedicinal herbs to treat their
diseases.
And before I ask you, yap, tocomment on that and where we go
after that, I want to ask Mike,if you wouldn't mind, where is

(23:40):
Yap coming from when he mentionsthat?
So can you describe a littlebit about why people might think
of chimpanzees first?

Well, I think the first global attention, or
at least in the popular press,about self-medication was
started from some early workwith chimpanzees.
For better or worse that got alot of attention and it kind of
went off in a strange directionin the beginning.

(24:06):
But I think most peopleassociate self-medication with
only large brain primates andtend to ignore that that should
happen in every species on theplanet.

So just, I mean, I know we've had you on
the podcast before and we'vetalked about self-medication,
we've talked about yourobservations of chimpanzees, but
maybe in the context of thisconversation now you could just
recount what like the majordiscoveries that you made with
chimpanzees and self-medication.

Well, in the beginning I didn't go in to this
topic on purpose.
It happened quiteserendipitously.
I was following chimps.
I was following a group ofchimps in which there were
several old individuals andyoung adults that I had picked
as targets.
I was actually looking at therole of old-aged individuals in

(25:00):
chimpanzee society because itwas at a time in the history of
research on that population thatwe had old-aged individuals.
We actually knew about how oldthey were.
They were in their mid to high50s and I was just starting my
work with chimps, so that was atopic that seemed ripe for the
picking.
Others were studyingself-medication and they were

(25:22):
talking about a behavior calledleaf swallowing.
But there wasn't a lot ofinformation about that behavior
yet and they were making a lotof claims about it, so I I
wasn't that interested in theidea, because it already is.
A lot of question marks werecoming up about the case being

(25:42):
made for leaf swallowing and thepeople involved in that were
also working at the same studysite.
But I happened to come acrosssomething that was different
from that.
That seemed like a strongercase for self-medication.
So I followed up over a coupleof days to see what would happen

(26:03):
to that individual thatingested a plant that my local
counterparts said was animportant medicine for them, and
so I began to try and figureout if that animal was indeed
sick, and then what happenedafter ingesting the plants, and
how similar was it actually towhat humans were using the plant

(26:24):
for?
And then that kind of it.
Just you know, it seemed like Iwas at the right place at the
right time and I had to try andfigure out what was going on.
So then I got interested andthen I went back to leaf
swallowing, to that firstbehavior and using the paradigm
that I established, and began tosee that in fact there was

(26:45):
something there, but it wasn'tat all what people thought in
the beginning.
So that at the time you knowchimps, of course chimps, but
nothing else can possibly beself-medicating Right.

And.

I didn't buy that from the beginning.
I didn't think chimps weredoing it because they were
necessarily smart, but becausethey're social learners and
there's a lot of observationallearning apparent in whatever
they do.
That's what I reported on first.
But there was work going on atKilt University with insects and

(27:24):
talking about sequesteringtoxic compounds and stuff.
So it seemed likely that itwould happen in many different
attacks.
And the more I thought about it, I said any species that isn't
self-medicating isn't aroundtoday.
Because they couldn't defendthemselves and then work like
what Yap has done.

(27:44):
It just really everything cameinto full circle and people
really started actively lookingand thanks to folks like Yap who
are looking at the insects andare able to come at it from a
different direction and kind ofdispel some of these ideas that
you have to be a large brainanimal to do something is so
much like us.
But yep and I have had thisconversation the humans are.

(28:08):
We're not special at all.
We're just an accumulation ofevery other animal that's that's
evolved before us yeah, so it'sa.

I mean I know that you also had your moments
there.
There's some resistance to theideas, but maybe we can come
back to how broadly understoodthis field now is.
But yeah, I want to turn backto you.
So you know, in the in maybe inMike's origin of this stuff and
observations in Tanzania wasstill challenging to push the

(28:37):
idea that apes might be capableof this.
Yet it's somehow easier for usultimately as a society to
accept that those kinds ofanimals as you mentioned, large
brain can are capable of thingslike that.
But kind of linking back towhat I asked earlier about how
in some cases people might seethat as more of in insects
especially a manipulation oftheir behavior rather than
something that they do indefense against parasites, so

(29:00):
maybe you can maybe step in thenand talk about what
specifically you found with themonarch butterflies.

Yeah, Well, I think what Mike said is very
nice, that he kind of stumbledupon it, right, and it's not
something he was planning tostudy.
It was the same for me I didn'tat all plan to study medication
in monarch butterflies, didn'tat all plan to study medication
in monarch butterflies.
But, like I said before, I wasstudying these, these parasites
of monarchs, trying tounderstand why they're causing

(29:26):
disease to the monarchs, which,by the way, means means that the
monarchs cannot come out oftheir pupal case.
They don't fly as well, theydon't mate as well.
So there's a lot of reallynegative consequences of this
infection.
But and we talked about thedifferent host plants and how
they use the chemicals toprotect themselves against
predators Now, as someone whostudies parasites, you then

(29:47):
think well, you know, predatorsare important, but parasites are
more important than some ofthese you know infectious
diseases everywhere.
And so really starting to think,also based on other studies
that were done in other systems,such as different moths, that
that could benefit from thechemicals and other plants to
kill viruses.

(30:08):
And so really the question was,these chemicals that protect
the monarchs against predators,do they also act against
parasites?
So that was the first study,and to rear monarch butterflies
and different plant species,infect them with, with very
controlled doses of parasites.
And this is that we found outthat some species of milkweed
are medicinal.
They really reduce theinfection of the parasite.

(30:31):
So it was very much a findingthat that, you know, started
just by studying the monarchbutterflies and starting to
think I never, you know theyears before that studying the
monarch butterflies and startingto think I never, you know the
years before that, I would neverhave predicted that it's
something I would study.
But once we saw that thesemilkweeds have such a big impact
on how sick the monarchs become, how infected they become, to

(30:52):
me it was a natural question toask.
Well, we know that otheranimals can medicate chimpanzees
and there was evidence forother species at the time too.
So maybe monarchs can do it too.
There definitely was resistancebecause when we wrote our paper
up to show that these milkweedscan reduce parasite infection.
In the discussion of the paperwe speculated that maybe

(31:14):
monarchs can take advantage ofthis, so when they're infected,
maybe they can preferentiallyuse the milkweeds that have more
toxins and are more medicinal,and one of the reviewers that
looked at our paper said that'sjust nonsense, there is no way
monarchs can do that, and theeditor told us to remove it from
the paper, and so we did not,happily, but we did, and then it

(31:35):
was a good motivator to saylet's show them they're wrong.
And so at that point I actuallygot a faculty position at Emory
University, where I'm now, andso one of the first studies we
did was put the idea to the test.
And so we did two types ofstudies.
The first one was to find outif caterpillars can
self-medicate.
So we infect caterpillars wehave, you know, we offer them

(31:59):
choices between diets, and it'snatural diets.
We grow all the plants in thegreenhouse.
We let them choose, foundabsolutely nothing interesting.
These caterpillars just eatwhatever comes in their way.
As long as it's milkweed, theydon't really care which species
it is.
But then we're really thinkingabout the adult butterflies.
Because when you think aboutcaterpillars, how do they end

(32:22):
end up on a plant?
It's because their mother laidan egg on that plant.
So it's the mother that reallydecides what that caterpillar is
going to eat, and I will saymonarch butterflies.
They don't really move thatmuch when they're caterpillars,
so it's the mother.
They put an egg on a plant.
That caterpillar is basicallystuck there.
That's where it's gonna haveits caterpillar life.
So then the question was can themothers make a decision?
So what we did then was anexperiment where we had mothers

(32:46):
that were either infected withparasites or uninfected.
We mated them with males andthen we set up big flight cages
in the greenhouse at theuniversity and in each cage we
put a medicinal plant, anon-medicinal plant, let the
butterfly fly around for twohours, let her lay eggs and then
simply count the number of eggs.
It's kind of cool that you can,you know, just counting that.

(33:07):
That was our data and we foundvery, very strong preference for
the medicinal plant by infectedbutterflies.

So how many milkweed or how many different
species of plant do you have inthe experiment?

So in this experiment we just had the two,
two, yeah.
So one medicinal plant, onenon-medicinal plant.
We chose the plant specificallybecause they differ in the
medicinal properties but arevery similar otherwise.
Right.
So they look the same, they'rethe same height, they have the
same nutritional properties, sothe same amount of carbohydrates
nutritional properties.

(33:41):
So the same amount ofcarbohydrates.
Yeah, it's because you know youlook at these preferences and
you want to make sure that thatwhat the preference is based on
is that factor that you'reinterested in.
In this case, that was thesecondary chemicals that were
associated with the medicinaleffects so in nature.

Then what is the I'm trying to?
I don't really know anythingabout milkweed, so is that all
within the the same genus thatyou have milkweeds, or are there
multiple genera?

It's mostly in one genus, asclepias, which is
named after the Greek god ofhealing, asclepius, which is a
very fun fact as well, and somost of them are within the
genus.
And in North America, where Ido my studies, mostly most of
the monarchs use anywhere up to30 different species of milkweed

(34:27):
, but you find oftentimes youfind different species of
milkweeds near each other.
But also it's important thatthese females can fly long
distances so they can easilymove between different patches
of milkweed.
And the monarchs are selective.
I've always been impressed.
I may be hanging out in amilkweed patch, a butterfly
comes along, she circles theplants, lands on it and then

(34:50):
oftentimes flies away withoutlaying an egg.
So they're super, superselective.
It's really intriguing and so,yeah, I think in nature they
definitely have theseopportunities to make these
choices.
And and you know, I, I think II'm still intrigued by it,
because what I find excitingabout it is that these, these
adult butterflies, already haveparasites, and what the

(35:10):
parasites do is they form sporeson the abdomen of the butterfly
.
So this female, this mother, isalready infected, because she
became infected as a caterpillar, because the caterpillars eat
up the spores that the mothersdeposit on the eggs and the
milkweed.
Then the parasites go into thegut.
From there they go into thetissues, from there they go to
the abdomen of the butterfly andthey just wait there for the

(35:32):
mother to to lay an egg and thenthey get dropped onto the eggs
and and the milkweed.
So what that means is that theinfected mother she's already
infected.
She cannot get rid of theseparasites.
She can also not stop thespread, because that's just a
mechanical thing.
When she lays an egg, some ofthese parasites just fall off
and get stuck to that egg or tothe milkweed.
So really the only thing shecan do is choose a plant that

(35:55):
will reduce the chance ofinfection and reduce the disease
symptoms for her offspring.
So it's really, you know,mother knows best.
That is how I like to describeit, she makes the decisions for
her offspring, which is cool.

It's very interesting.
I noticed earlier when I wastalking about self-medication,
you made the very clear point ofcalling it medication and I
think that's because of thisright that you have
intergenerational Absolutely.

You picked up on that.
So that's really what I'mtrying to call it medication, to
make it a little bit moreinclusive.
We see this with the monarchbutterflies, but we also see it
with other species such as antsand bees.
They incorporate resin thatthey get from trees into their
nest and they're not medicatingthemselves with that, they're
medicating the rest of thecolony with it.

I guess this also applies to, maybe, bird
parents that will fumigate theirnests with different absolutely
, absolutely, even, even there'sexamples recently of chimps
treating others wounds andthings, that that whole story
isn't really clear yet.

but it's really exciting because it's a
habitual behavior and it's oneeither applying a potentially
meditative substance to a woundor even selecting the substance
and passing it on to anotherindividual, who then treats
another individual, or theycould even treat themselves.

(37:14):
But it's just, the more we look, the more we realize we really
don't understand yet Sure.

And it's also interesting to think with chimps
.
I mean it's maybe for us,because we're so similar to them
, it would be easier to imaginehow they might detect the threat
of parasites and the need tokind of act or counteract.
So that would be in atherapeutic sense.
There's also this idea thatanimals can preempt or prevent
the acquisition of parasitesthrough those kind of behaviors,

(37:43):
but with the monarchs.
What is our currentunderstanding of how those
mothers might detect thesituation, how infected they
might be and which milkweedsthey should target because of
that?

It's a really wonderful question and it's
something we don't really havean answer to yet.
That it's a really wonderfulquestion and it's something we
don't really have an answer toyet, but it's very exciting is
that there is anothercaterpillar species that we
understand much better, and thisis research done by by other
people in the field, and theyhave looked at woolly bear
caterpillars that often getinfected with parasitoid flies.
These are, you know, we cancall them the kind of the aliens
of the natural world right sothese fly lay flies lay eggs on

(38:20):
the caterpillar.
The maggots eat their way intothe to the caterpillar and then
grow and then eat their way out,and so it's really like the
alien movie in some ways.
But research had shown thatwhen these caterpillars eat more
alkaloids in their food, thatit reduces infection and it can
actually kill these parasitoidflies.

(38:41):
And then the researchers didexperiments to show that when
they're infected they eat moreof those alkaloids, so they
choose food that has more ofthese chemicals.
And what is very intriguingabout the system is that these
caterpillars have four differenttaste receptors in their mouth
and one of them is specificallydetecting the alkaloids.

(39:03):
And doing some very carefulexperiments with tiny little
surgery and and electrodes theycould show that when the
caterpillars are infected theyhave the.
These taste receptors for thosespecific chemicals were firing
at much higher rates.
So in a way they developed a, ataste for this medicine.
So I think similar things maybe going on in the monarchs.

(39:25):
I already told you thatmonarchs often land on a plant
and then they fly away or theylay an egg.
So first they see the plant,they smell the plant, but a lot
of it is based on taste.
So they can taste the plantwith their feet, with their
abdomen, with their antennae,and then oftentimes you see them
go away.
So I think that the way I thinkabout it is that disinfection

(39:48):
changes their whole physiologyand so they just become more
sensitive to particularchemicals and probably more
attractive to the plants thatare more medicinal.
Right, you know, and it's nicebecause I can walk into the
greenhouse.
I always tell my students youcan blindfold me, take me to the
greenhouse and I will pick outthe medicinal plants for you,
because I can smell them and soyou?

(40:09):
you know, if I can do it, I'msure a monarch can do it better
than me.

Incredible this is the exact same mechanism
that I've read about withchinese medicine humans doing it
to humans being their, theirtaste, perceptions or cravings
or aversion when they get better.
It's going on and we're tryingto understand that in and other
animal models.
I think.
To think that even that samemechanism is going on with the

(40:34):
insects is tells us how old thisbehavior sure really is.

Yeah, tells us how old this behavior really is
.
Yeah, and what so?
Oe?
I don't remember the actualscientific nomenclature of that
parasite, but what kind ofdamage does it do to the adult
monarch?

Yeah, so the full name is Ophryocystis
electroschera and that's whymost people call it OE.
It's a real mouthful.
Yeah, so it's like I saidearlier.
So it infects the tissues andthen, as the caterpillar, molds
multiple times and then goesthrough the metamorphosis to
form from the pupae to the adult.

(41:10):
The parasites move towardbasically what becomes the
scales and the skin of thebutterfly, and so they form
there and that means that thescales cannot form.
So you basically have littleholes all through the skin of
the butterfly and so they formthere and that means that the
scales cannot form.
So you basically have littleholes all through the the skin
of the butterfly.
So they lose a lot of liquids,they're they're really
dehydrating and so, with veryheavy infections imagine you

(41:31):
have millions of those littlelesions on your body.
The butterflies get stuck to thepupal case.
That means they will never comeout as a, as an adult butterfly
.
They will never fly, never mate, they don't survive.
Um, the ones that do come outdon't live as long, and I think
that also has to do with the,the loss of water.
I think they also have damagedtissues, so they just don't do

(41:52):
as well.
They don't fly as well, whichis really important for a
butterfly that needs to fly upto 4 000 kilometers to
overwinter, so that's a that's abig thing.
And they don't mate as well.

So in fact, the butterflies are just not very
successful at at mating andreproducing yeah, so when, when
the larvae start eating themilkweed, they already have some
of these parasites on them,does it kill the parasites
themselves or does it preventspread?

(42:26):
Or what's the level of action?
Or is it multiple layers?

We don't really know the level of action yet.
All we know is that when themedicinal milkweed and the
parasites are ingested at thesame time, that is when the
medicinal milkweeds have aneffect.
If the monarch is alreadyinfected and you feed it
medicinal milkweed, it no longerhas an effect.
So I think the plants reallyhave a way to stop the parasites
from infecting the caterpillarin the first place.

(42:53):
Whether that's a direct toxiceffect or whether it's through
the microbiome, that's actuallysomething we're investigating
right now.
But really kind of preventingthe parasites from going in is
really important.

Is there some kind of a fumigative effect of
laying eggs on a plant like that, in addition to the effect of
it ingestion by the larvae?

That's a really good question.
I haven't really thought aboutit.
I think one way you could testthat is to put the parasites on
those plants, take them offagain and see how mobile are
they?
Well, they're uh, they don'tmove themselves, but we we can
pick them up.
They're about 40 micrometerslong, so you can have a little
glass capillary, make a littletool and they will stick to it.

So they don't move around on the whole.

No, no, no, no, they're just sitting there.

Passively ingested by the catterpower when
it moves around.

Yeah, they're passive, they just get stuck
there and that's it.
But we can move them.
We could do that.
Yeah, it's a good idea.

There we go.
Yeah, you, it's a good idea.
There we go, yeah.

You heard it right here folks Generating
ideas on the private cast, yeah,Look forward to seeing that
Before we go on.
You were talking about thealien.
You gave that image and itstuck in my mind.
We had Sigourney Weaver, whodealt with the aliens in the
insect world.

(44:20):
Are we talking about SigourneyWeev, who dealt with the aliens
in the insect world?
Are we talking about Sigourney?

Weevil, here we go.

Sorry.

I don't even have an answer to that.

You're not supposed to.

I could try and describe Yap's face right
now, but I think we can move on.

It assumes people know what weevils are.

They're not monarchs.

They're a little beetle yeah.

Yeah.
So I I'm curious and I want tocome back to this later when we
maybe close the interview aboutyour the book that you're
working on and you don't have togive too many spoilers.
But I want to ask you, andespecially since we have Mike in
the studio with us, has therebeen anything related to to to
medication in the animal kingdomthat you've been researching
that kind of blew your mind whenyou, when you read about it or

(45:05):
or tickled you in some way?

maybe you could just kind of relate one or two
stories about that yeah, I thinkit's, it's all blowing my mind,
you know, I I think it's justso intriguing and I think I'm
still coming to grips myselfthat animals can do this.
And you know, I think, likemike and I both said earlier,
you know, when you make thesediscoveries, there's always this
kind of initial resistance andit's something I have heard from

(45:29):
everyone who has been studyingself-medication or medication
and species, um, you know,anywhere from birds to
chimpanzees, to ants, to beeskind of this initial idea of
there is no way.
So I think we're still and Ithink that's the Western
scientific tradition, where welike to think we're extremely
special and so and we think of,you know, some animals being

(45:51):
smarter than others.
So, yeah, we can live with thefact that chimpanzees can do it.
Insects cannot.
So some really amazing, amazingstories.
One of my favorite stories isthat of finches and sparrows in
mexico city, and I went tomexico city last summer, in june
, to meet researchers there whohad been studying these birds,

(46:13):
what they noticed, that and andother thing they they didn't
mean to study medication inthese birds.
They wanted to look aturbanization and see how birds
adapt to urbanization.
So when they building theirnests, what do you find in those
nests?
Do they use natural materialsor do they put plastic in, or
you know other things that thatpeople made?
And what they found is that thebirds put cigarette butts in

(46:36):
their nests, and what they foundis this kind of white, fluffy
material.
They didn't know what it wasuntil it rained and they could
smell the smoke and they said,okay, so these birds are picking
up these cigarette butts,pulling them apart, putting the
little fibers in their nests.
Why are they doing this?
And so they started with thisbeautiful correlational study,
finding that nests that had moreof these cigarette butts had

(46:59):
fewer parasites.
And so we talk aboutectoparasites, which is lice and
mites and ticks.
And then you know, so that gavethe idea oh, maybe these birds
are putting these cigarettebutts in their nests as a as a
medication, as a fumigation inthis case.
And then they followed up witha beautiful experiment where
they said, okay, well, we wantto actually test this idea.

(47:20):
So they made artificial nests,artificial linings for nests,
and then they either added liveticks that suck the blood of the
birds, or they added ticks thatwere killed, or they added
nothing as a control, and theyfound that the birds with the
live ticks, collected a lot morecigarette butts and also found

(47:40):
that those chicks were doingbetter.
They grew better.
So it's a really intriguingexample, right, because it takes
you full circle the idea thatanimals cannot do this, and you
know.
And then you find that animalscan do it and in some ways we're
even helping them by, you know,littering these cigarette butts
.

We should take a moment to intervene, though,
and say that the primate cast inno way, shape or form, supports
cigarette smoking Absolutely.

Yeah, I think the cigarette industry.
But what it showed to us, Ithink, is that there is this,
these abilities that theseanimals have to find these
medicines in nature, and theyhave some some mechanisms by
which they can recognize them.
But I did ask that questionbecause, you know, there, for
example, at emory university,where I work, there are no

(48:30):
cigarette butts because we havea cigarette ban on campus, so
our birds could never do this.
So I I asked, kind of ingestfun, you know what, if you going
to take care of thesecigarettes and make people stop
smoking, is that bad for thebirds, right?
But the researchers said no,because they're so adaptable.
What they can do instead, andwhat a lot of birds do, is use

(48:51):
aromatic plants, and so they canfind tobacco plants, they can
find other plants that have thesame function as their cigarette
butts.
It just so happens these birdsthat live on a university campus
in Mexico City they're, youknow, surrounded by these butts,
so they only have to fly 10meters to get their medicine
rather than fly 100 meters.

So they'll do that.
So, if anything, this is stillreinforcing the idea that we
should take better care ofnature so that the animals can
sort it out themselves.

Yeah, because you know, the cigarette are not not
harmless either for the birds.
So they actually have somedefects in their blood cells.

So it's it's not you know, we all know
smoking is bad.

It's also bad for birds yeah so yeah, I, I agree
with you.
It reinforces the idea that youknow it.
This is a cool example, butwouldn't it be nicer if the
birds could just use the plantsif they were still available, or
we can replant them and makesure they can use those?
So yeah, but yeah, that wholething has blown, blown me away.
I think it's such a wonderfulexample what, mike?

what about?
I mean, you've been in thisgame for quite a while and
you've seen a lot and you'veyou've been an advocate for a
lot of different ideas that thatfolks around the world have had
about self, aboutself-medication and medication
in animals, and so, um, maybeI'll ask the same question to
you, like what kind of over theyears, apart from your original
observations of of chashkachimpanzee, but what has kind of

(50:06):
most surprised you as we'vegone forward and learned more
about this area?

I think what amazes me most is how some
behaviors repeat themselves inso distant taxa.
Snow geese, grizzly bears,japanese monkeys, gibbons,

(50:31):
chimpanzees, bonobos, gorillas,cats, dogs are all swallowing
leaves or grass and they're allexpelling parasites.
Obviously, it's not somethingthat's only found amongst chimps
, you know.
It's just the fact that thesesimple strategies have been

(50:57):
reinvented or have just beenmaintained all across the
evolution of animals.
It's amazing, and it's alsonest fumigation Animals that
build burrows and stay in thesame place for a long time.
They're doing the same thing,and Yap brought this up.

(51:26):
I forgot what Yap brought up,but what I lost, my train of
thought, but the fact that, well, okay, in Mexico City it's
easier to get cigarette butts orthe filters from the cigarette
and pull that out and put thatin the nest.
But those birds in Mexico Cityare identifying, in the same way

(51:48):
that birds in France or thebirds in Africa and North
America are, to certain smellsand certain things that that
tickle their brain, tickle theirinstincts to to add in into the
nest when they're facing acertain problem.
They know that this willrelieve symptoms.
They may not know the speciesof tick that are in their nest,

(52:10):
but they know what theconsequences of having something
like that in there.
And that mechanism is in therefrom humans all the way down to
monarch butterflies, and I thinkthat alone should convince
anyone that, no matter whatspecies we're thinking about,
they're all self-medicating.

(52:32):
If you just think of it as avery simple predator-prey system
, they don't have to be lions,they don't have to be something
really big and loud for us tohave to avoid them.
They can be inside of us, theycan be on our mothers and we're
getting them when we're born.
Um, it's a very simple, verybasic principle and, and

(52:57):
hopefully more, if we can getpeople to think of it from that
perspective, we'll have a lotless problem publishing papers
and I think in the end, everyonewill will accept that this is
so.
You know, it happens a lot inscience.
I think this is so simple.
Why didn't we think of itearlier?
Or, of course, this yeah, ofcourse that's what's going on

(53:19):
and I think we're almost therefrom my perspective.

I mean it looks like you gained a lot of
traction.
So and I do like the point youmake I mean the grasses, for
example, that those leafswallowers are using would be
different everywhere that youfind them, yet the concept is
kind of the same.

And the principle of the leaf is very
similar.
It's not just the behavior, butit's the leaves that they're
selecting, and it's all for aspecific function.

Yeah, super interesting.
And I think all three of ussitting at this table can agree
that parasites are far moreimportant and interesting than
predators.
Yes, so I appreciate you.
You mentioned that earlier.

Yeah, I, I was gonna say you earlier asked you
know things you have found thatare really interesting or
tickling.
You know your, your interestand you know I.
I think one thing that wehaven't mentioned yet is just
the, the applications that wecan get from that would be my
very next question okay, perfect.
So you know it's I.
I'm really a basic biologist, Ilove nature and I just love

(54:21):
understanding these things.
But at the same time it's alsoso interesting to learn how much
humans in the past have alreadylearned from animal medication.
And you know, I think one thingthat we haven't emphasized yet
is that the things that Mike hasdiscovered, the things that I
have discovered, the things thata lot of us have discovered,
are really rediscoveries.
And when you look at thetraditional knowledge and

(54:44):
traditional healers, they haveoften looked at animals and,
like Mike said earlier, earlier,you know, really understanding
what the chimpanzee was doing,based also on the knowledge of
the.
The traditional healer that wasworking with mike and guiding
him through the forest reallytells you that we have lost some
knowledge that we are nowregaining.

(55:04):
But when you go back and youlook at it and you find out that
people have looked at animals,learned from them and created
medicines.
There's even some indicationsthat the drug aspirin, which
comes from the bark of willowtrees, that has its origin with
bears.
Bears have been a really goodexample for humans all over the

(55:26):
Northern Hemisphere as a masterof medicine.
A lot of shamans would dress upor behave like bears, get in
trance-like states to be likebears and dream of bears and
bears.
What they do is, after theycome out of hibernation, they're
completely.
You know.
They have been in hibernationfor months.
They're stiff, they're in pain.
First thing they do is eat thebark of willow trees and get all

(55:50):
that salicylic acid that is ananti-inflammatory, and so and
that's just one example, and Ithink there's plenty of other
examples where we already havelearned from animals, without
some of us in the Westremembering it but also opening
up new avenues, you know,finding out about new drugs that
we may still discover bylooking at animals, which I

(56:11):
think is a really interestingpossibility.

Yeah, I think you made a.
You gave a.

it's on your website, but you gave a six
minute TED talk about this, andI think you closed your talk by
making a prediction, which wasthat one day we'll be using
medicine discovered bybutterflies and yeah, you know,
I think maybe we already are,without us knowing it, and I
think a lot of medicines that weuse, even today, a lot of the

(56:38):
drug discovery is based onplants and a lot of the initial
indications.
There's a whole field ofethnobotany where scientists
talk to traditional healers andlearn from their knowledge, but
the question is, where does thatknowledge come from?
I wouldn't be surprised if alot of that knowledge came from
animals, maybe even somebutterflies.

I might do.
I've often been asked when Igive talks like this is there a
plant out there that is now usedas medicine by the research
with chimps?
And I always used to giveexamples.
Well, bernonye is a very goodexample, but it's not something
you can buy across the counterin a Western pharmacy or in a

(57:20):
drugstore.
But I started thinking more andmore and I said the question
should actually be redirectedback to those people.
Tell me a medicine that wasn'tderived from plants, that
animals weren't using beforepeople were on this planet.
So everything we use basicallyis derived from nature.
So that means from the animalsand from the plants.

(57:43):
But to specifically think ofthis medicine coming from
butterflies.
I think would really be cooland it would maybe bring us all
a little bit closer together onthe planet not just humans, but
everyone.

Yeah, so I, there's so many transitions I
wanted to kind of make from thatlast little bit that you said.
So this is going to come up asa little bit awkward, but two
things I think we can close out,uh, after that.
But there's two things I wantedto I wanted to talk about while
you're here in the studio, yeah, and the first one is monarchs,
uh, and migrations, because Ithink that topic itself is, when

(58:21):
people think of monarchbutterflies, apart from the the
visually striking orange, uh,coloration they have the
migration is another, anotherhuge thing that comes to
people's mind.
And then maybe we can just closewith something that's very
related to what you just talkedabout, which is the messaging
behind self, not just medicationbut just in general science
messaging.
And you know, I wanted to catchyour thoughts a little bit on

(58:44):
the process of writing a bookfor those in the audience who
may be interested in thatprocess.
We all love reading popularscience books.
It's a great way to kind ofengage with the material, and so
, if you don't mind, maybe wecan just close with those two
things.
So first, monarchs.
So you've been studyingmonarchs now for a couple of
decades I suppose.

Since 2005.

Getting up there and what is so you came at
it from this idea of beinginterested in parasites,
infectious disease and ecology,but what has really struck you
about studying monarchs and thenmaybe we can get into the
migration?

I think the thing that surprised me the most was
how little we know about monarchbutterflies.
Little we know about monarchbutterflies you know for, such
as popular species.
You you google butterfly on theinternet or you see any
advertisement campaign.
Even I was in the netherlands afew summers ago, rented a bike
at a shop and theiradvertisement featured a monarch

(59:41):
butterfly.
That makes no sense.
There are no monarchs in thenetherlands there is there.
There is a history with ourroyal family, but I I thought
you know, for such a popularspecies we know a lot more than
than we do, and it's stillintriguing to me.
One of the the major questionsis their migration.
How do they know where they'regoing?
Or, to rephrase that, do theyknow where they're going?

(01:00:04):
I mean, that in itself is areally interesting question.
So monarchs that are are born ascaterpillars toward the end of
the year, so the end of thesummer, in southern Canada, the
northern United States.
They do not develop intobutterflies that are going to
breed and produce morecaterpillars.
They're developing into migrantbutterflies and so when they're

(01:00:26):
adults they just start flyingsouth and then after some time
they make it to overwinteringsites in central Mexico, high up
in the mountains, in particulartrees.
From year to year they go tothe same places, but every
butterfly only makes the journeyonce, and in fact most
butterflies never make thejourney, because what happens in
the spring is the butterfliesgo north, they lay eggs and it's

(01:00:48):
the next generation that goesfurther north and then yet
another generation that makes itall the way to canada.
So it's only one in three orfour generations of monarchs
that migrate.
They only migrate once, so theyhave no way of learning from
others.
There are no, you know, olderbutterflies there to guide the
way, so it is completely innate.
They, they fly south, they endup there and the question is do

(01:01:10):
they need to know?
Do they know where they'regoing, or are they just flying
south and the landscape bringsthem there?
That's something we don't knowand it's it's really intriguing,
um, that you know, for aspecies so well studied.
That's something we didn't know, and so that's still something
that a lot of people are workingon.
We are working on that questionright now.
I think it's a very difficultquestion to tackle, but, yeah,

(01:01:33):
most surprising thing to me wasthat there's so much we still
need to understand.

Andrew MacIntosh (01:01:38):
Yeah, that's really and also important.
So, especially with climatechange, I know that for monarch
butterfly monitoring there's bigcitizen science projects where
people report, basically whenthey arrive and we we have
really great data.
Because of that it's beautiful,yeah, but so what and I think
I've read that you've writtenthis OE parasite as well it

(01:01:59):
seems to be increasing.

Jaap de Roode (01:02:01):
Yes Over time.

And I'm wondering you said earlier in
this interview that that has animpact on migration so what is
the kind of current status then,from your perspective, of
considering climate change,considering just habitat?
I mean environmental change too, and urbanization yeah, lots of
everything.
And now the parasite story lotsof challenges so parasite

(01:02:23):
prevalence has increased.

So until about 20 years ago, maybe one in a
hundred butterflies wereinfected with this parasite in
North America.
Now it's about one in 10.
So that's a lot.
Now, given that the parasitereduces their ability to fly, it
really kills a lot of monarchsduring that migration.
And that's actually interestingbecause in some ways this
migration really gets rid ofthese parasites.

(01:02:46):
So it's in a way a treatment,because the most infected
butterflies do not make it.
So you get rid of a lot ofparasites from year to year, and
so the population starts kindof at a low level of parasitism
again the next year.
But on the other hand, for anindividual monarch butterfly
that's infected, that butterflyis not going to make it to
Mexico.
It's not going to survive, it'snot going to reproduce, right.

(01:03:08):
So when we see this increase inparasite prevalence, it's
really detrimental to themigration, and so we did a
calculation in a recent papersuggesting that tens of millions
of monarchs die of thisparasite on their way to Mexico
every year.
So that's a big deal.
At the same time, yeah, climatechange is going on, and so
there is a lot more milkweedgrowing in the United States now

(01:03:30):
that doesn't die back in thewinter.
That means that monarchs canreproduce throughout the year
and that increases that parasiteprevalence as well.

So you have sedentary populations.
That's right, yeah, yeah.

So yeah, and so you know the things we can do
about that.
You know, like you said earlier, there are a lot of citizen
scientists that work on monarchs.
And actually brings me back toanother thing you asked you know
what has surprised you aboutmonarchs?
I think it is so amazing thatmillions of people rally around
an insect.
I mean, you know, and I'm stillI'm still in Proveco to monarch

(01:04:06):
butterfly festivals.
People dress up like monarchs,thousands of people come to
these festivals, people lovebutterflies and I think it's
great because you know that's aninsect and generally people
like fluffy animals, but notthese insects.
So I think that's great and thatalso means we can use them as a
rallying species.
I like to call them theambassador of the insect world.

(01:04:27):
People rally around monarchs,not the average weevil or
cockroach or whatever, but byprotecting monarchs we can
protect all the other insectwildlife too.
So I think you know recreatinghabitat you mentioned
urbanization earlier.
So building pollinator gardensthat include plants that
monarchs can use, but nativeones that die back in the winter

(01:04:49):
, those are the things that wethink are important.

I think I read recently an article about this
in the us, where insects don'thave any kind of status, of
conservation status, for example, so there's really no body that
can work towards supportingtheir most, yeah, most, state
legislatures don't have, or orstate constitutions have defined
butterflies as animals andtherefore they're um, they're

(01:05:14):
hard to to regulate allegedly,yeah, yeah and I know that you
also work on bees.
We're not going to get into thatbecause that's a whole other
topic maybe we'll save it foraround two of the podcast yeah
but uh uh, also very importantthat we we change our ideas
about these organisms to do moreto protect them Bees obviously
being incredibly important forour food security.

And also monsters at medication.

Yes, so maybe last thing then I just want to
talk a little bit about sciencecommunication.
You noted earlier in thisinterview that when you were
doing more journalistic work,you also have a background in
science writing, I believe, andnow you're working on this book.

Michael Huffman (01:05:56):
So can you maybe talk a?

little bit for anyone out there who is maybe a
young academic or it might beinterested in science
communication.
How does that work for you?
I mean, do you recommend peopletry and get some kinds of
certification in science writing?
Has that helped you a lot?
And then, how did you come tothe idea of writing a book about
medication?

So definitely having done science, journalism.
So I started during myundergraduate degree.
I actually took a course in itand then I did a lot of
freelancing.
I did a full-time year offreelancing and then even during
my PhD I still wrote, maybeonce a month wrote an article.
I think it's incredibly useful.
I think it really helped me getmy scientific papers written.

(01:06:39):
Just the idea of I just need toget this done you know, working
with deadlines in the popularpress, you cannot sit around
forever thinking about youropening sentence, you just have
to get it done.
So getting that familiaritywith writing was super helpful.
I think the best compliment Iever got was when I wrote a
thesis chapter draft and one ofthe professors on my committee

(01:07:02):
said that it was too easy tofollow.
It read like a journalisticarticle.
I said, well, good, that meansthat it was easy to read.
So I think it's very, veryuseful and it was fun.
But it's also helped withscience and you know, within our
scientific fields we also haveto popularize right.
Yes we talk to experts in thefield, but no one is as expert

(01:07:24):
as we are on the specific thingswe do.
So when we give a talk or make aposter, write a paper, we still
have to try to convey themessage in the best possible way
, and so writing the book now isreally my way of going back to
my initial passion for sciencewriting.
You know, getting into thescientific career, I I still
wrote scientific popular sciencearticles during my ph, but then

(01:07:48):
, since then, the research tookover and the teaching took over
and the research administration,and so this was for me.
I had a half year sabbatical atEmory and I said this is the
time to go back to that andwrite something very exciting.
And you know, by that time Ihad developed a strong interest
in the topic and, always talkingabout it, never found anyone

(01:08:10):
that didn't find it interesting.
So I thought it's a great topicfor a popular science book
where we can talk about thiscool nature but also talk about,
but we can learn from it andmaybe create yet another
rallying cry to conserve nature,save our planet.
You know, even even the thoughtof replacing part of your green
front lawn with some wildplants, pollinator plants,

(01:08:34):
medicinal plants, you knowproviding medication
opportunities not just for theinsects in your garden but for
your pets, your cats and yourdogs, right, and then maybe for
our future drug discovery.
I think it's a, it's a reallycool idea yeah, do you have.

So you mentioned um writing for, for
for the media.
You have deadlines and soyou're basically doing it all
the time since your phd.
You hadn't done it very much,but did you try.
Do you journal, for example, ordid you try to find ways to
keep the practice up in thatinterim?

no nothing no, I mean, you write so much in this
job.
I I find it, I found it hard touh to keep on doing that right,
yeah so spend a lot more timewriting papers, grants and edit
student papers and everythingand that's also fulfilling.
Yeah but I was ready to, to goback to the more kind of

(01:09:25):
creative writing, right and uh,starting with that sense of
wonder, yeah and being lessrestricted by the the formats of
a scientific journal right wasthere any um like leading up to
this, this decision to take iton?

were there any uh books that you yourself just
really enjoyed and kind ofwanted to model yours after that
you can think of at the moment?

I.
I've always loved readingpopular science books.
I think one of my friends fromthe Netherlands he was a postdoc
in the lab where I was anundergraduate student.
His name is Menno Schildhuisen.
He has written multiple popularscience books and the book that
kind of inspired me, I think,is a book called Darwin Comes to
Town where he talks about howspecies are adapting to

(01:10:10):
urbanization and urban life andit's a combination of really
talking about the science butfeaturing the people who do the
science in that book.
And I think that's somethingI'm trying to do as well,
because I like to show peoplethat science is a human
enterprise and different peopledo it differently and people are

(01:10:32):
driven by these different ideas.
So I'm trying to feature thepeople and the places as much as
the science, and I think thatwas inspired by that book.

Great.
Well, we're definitely happythat you were able to, you know,
follow through on that and comehere and visit Mike and Inuyama
and have a chance to talk withyou here for the PrimateCast
aptitude.
Thank you very much for joiningme on the primate cast.
Thank you so much, mike.
My pleasure.
Great to have you in the studioas well always my pleasure.

All Episodes

Episode Transcript

Popular Podcasts

Stuff You Should Know

Dateline NBC

On Purpose with Jay Shetty

.css-15opob5{left:0;position:absolute;top:0.8rem;} All Episodes

.css-14f5ked{margin:0;word-break:break-word;display:-webkit-box;-webkit-box-orient:vertical;box-orient:vertical;-webkit-line-clamp:2;overflow:hidden;}Nature's Apothecary: Monarchs, Milkweed, and the Art of Self-Medication with Dr. Jaap de Roode

Episode Transcript

Popular Podcasts

.css-r6mb8g{margin:0;word-break:break-word;display:-webkit-box;-webkit-box-orient:vertical;box-orient:vertical;-webkit-line-clamp:1;overflow:hidden;}Stuff You Should Know

Dateline NBC

On Purpose with Jay Shetty

All Episodes

Nature's Apothecary: Monarchs, Milkweed, and the Art of Self-Medication with Dr. Jaap de Roode

Stuff You Should Know