May 14, 2024 • 50 mins
In this episode of Stuff to Blow Your Mind, Robert chats with evolutionary biologist and historian of science Lee Alan Dugatkin about his new book “The Well-Connected Animal: Social Networks and the Wondrous Complexity of Animal Societies.” You'll learn about the complex social networks of vampire bats, dolphins, bees and more.
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Speaker 1 (00:03):
Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 2 (00:13):
Hey, welcome to Stuff to Blow Your Mind. My name
is Robert Lamb. Today I have an interview episode for you.
I recently spoke with Lee Alan Dugatkin, a professor of
evolution and behavior at the University of Louisville in Kentucky.
He is the author of the new book The Well
Connected Animal Social Networks and the Wondrous Complexity of Animal Societies.
(00:37):
This book comes out this Thursday, so wherever you get
your books, in whatever formats, you can probably go ahead
and pre order it. If not, grab it on Thursday.
It's a delightful read. And this was a delightful chat.
I really enjoyed talking with Lee. Let's go ahead and
jump right into the interview.
Speaker 3 (00:59):
Hi.
Speaker 2 (00:59):
Lee, welcome to the show.
Speaker 3 (01:00):
Thank you for having me. I've been looking forward to it.
Speaker 2 (01:03):
So you're an evolutionary biologist, an historian of science, and
an animal behaviorist. How do these classifications triangulate on your
work and how did you get involved in your field?
Speaker 3 (01:13):
Yeah, so I got involved in a sort of circuitous way.
I really didn't know what I wanted to do, even
when I was in college. I happened upon the study
of animal behavior and evolution, and a friend of mine
mentioned a book he was reading, and before I knew it,
(01:33):
I was in graduate school studying evolution and behavior and
non humans because I just fell in love with the
topic and I thought it was sort of the ultimate
kinds of questions one could ask about life on the planet.
And so early on a lot of my work was
experimental work with animals. I looked at the evolution of
(01:53):
cooperation and the evolution of aggression and so on for
many many years in my laboratory. And then about fifteen
years ago or so, after I had been doing this
for a couple of decades, I started getting much more
interested in the history of the subjects that I was
(02:13):
working on. So it turns out that all of the
people early on who were studying the evolution of cooperation
were really fascinating characters in and of themselves, how they
came about it, the environment, and the kind of social
atmosphere in which they developed their ideas. And I began
to become much more interested in that aspect of the work.
Speaker 2 (02:36):
And so.
Speaker 3 (02:39):
All these areas dovetail in the sense that I still
do work on studying evolution and animal behavior. But I
also have had this component of it's worth stopping for
a minute and realizing that, you know, in the late
eighteen hundreds or something like that, here's how these ideas
came about. Here are the people who did it, and
(03:00):
here's the kind of social environment in which it happened.
And I think it makes the study of science itself
much richer to do it that way.
Speaker 2 (03:08):
The new book is The Well Connected Animals, Social Networks
and the Wondrous Complexity of Animal Societies. Could you walk
us through what a social network is and say sociology
and anthropology and how and when the concept enters into
contemplation of non human animals.
Speaker 3 (03:25):
Sure, And you know, I should say that there are
many many different definitions of social networks, depending on exactly
what discipline you're interested in and how mathematical you want
to get for me, and I think from I think
this is a reasonable general definition. Is a social network
(03:46):
is just a group of individuals through which information travels,
And it may travel directly and it may travel indirectly.
And it's also a group of individuals who somehow are
other affect one another in a real way. And again
that could happen either directly by your interaction with Steve,
(04:10):
or it could happen indirectly because you interact with Steve,
and Steve interacts with Nancy, and so Nancy is affected
by what you have done to Steve. And so generally
it's this information flow and effect on others in your network.
That's that for me, is the key to social networks.
(04:34):
You know, humans are in all sorts of social networks,
Facebook and that sort of thing, but we're also embedded
in them in almost everything we do in life. Are
our families or one kind of social network? Are the
people we work with or another, our friends or another,
and so on, and they all overlap. Now, in terms
(04:55):
of the history of the subject, I mean, anthropologists and
particularly sociologists have been interested in this in humans for
quite some time. It was, you know, in the nineteen
forties and nineteen fifties where people first began to get
(05:15):
serious about trying to understand the details of what we
now would refer to as social networks how they work
in humans. And that involved a lot of mathematics in
terms of understanding what it means if I interact with you,
(05:37):
and you interact with somebody else and that somebody else
is affected by me, and who is Who are the
key individuals in the social network, the ones that have
the most impact, and are there cliques where certain individuals
tend to interact with each other more? And that really
began to flourish, I would say, in the nineteen forties
(05:59):
and fifties in anthropology and sociology what we now refer
to as a social network. I think that language became
much more common in the late nineteen hundreds and into
the early two thousands. Now when it comes to studying
(06:21):
social networks and non humans, we can trace it back
quite far in the sense that even in Darwindnesday and
a little bit later, so the late eighteen hundreds, people
were beginning to think that the same kind of social
tools that can be used to study human behavior can
(06:44):
be used to study animal behavior. And so there are
people who were basically arguing that animal societies were structured
very much like human societies. And even though the word
social network wasn't around, the idea idea that we could
study non humans like we study humans was there. It
(07:05):
really began to flourish more again around the same time
as early work in humans did. That is, in this
case maybe the nineteen fifties and nineteen sixties when primatologists
people who study monkeys and apes, began to think in
terms of social networks. They began to realize that information
(07:29):
was flowing through these non human groups, again mostly primates,
in a way that was similar to the way it
flows through human groups. And it really mattered in a
group of chimpanzees, if one chimpanzee groomed the other and
got bugs and parasites off it back, it really mattered
(07:50):
who they groomed and who that individual groomed, and how
that kind of grooming social network developed. So it first
started with non human primates, which kind of makes sense
because there are closest evolutionary relatives, and then it began
to branch out in the nineteen eighties and nineteen nineties
(08:12):
when people began to study it in all sorts of organisms.
In fact, the two classic studies early on were done
in dolphins and in birds. So it's been around in
a serious way in the animal behavior literature for on
the order of twenty to thirty years. Now.
Speaker 2 (08:32):
Okay, so the roots go back a bit deeper, but
it's really taken off in recent decades.
Speaker 3 (08:38):
Absolutely, absolutely in fact, right now, the study of social
networks in non humans is probably is one of the
most active areas in the entire field. I mean, anytime
you open up a journal on behavior and non humans,
you're likely to find an article about social networks. And
those networks are important in almost every context for non humans.
(09:00):
There are networks about feeding, there are mating networks, there
are traveling networks, there are cooperation networks, there are power networks.
Everywhere you look. Now that we've started to actually explore
it in depth, we're finding it. And this is sort
of what happens in animal behavior a lot. We tend
to think of things initially as strictly human, and then
(09:22):
when we begin to probe deeper, we see similar sorts
of things in non humans, and once we begin to look,
we begin to see it everywhere.
Speaker 2 (09:30):
And to be clear, with humans, we're talking about multiple
social networks being in place for a given individual or
a given group. But the same is true of these
various animal examples as well. Right, We're not talking about
just like the social network of the macaque. We're talking
about like the multiple interconnected social networks.
Speaker 3 (09:49):
Right, absolutely, So it might be that you're studying networks
in the sense of who's going around feeding with who,
and who's sharing food with who. But in that same species,
you might be looking at who's being aggressive towards who,
and who's traveling together, and who's being nice to who,
(10:11):
and all of those are overlapping networks in the same
sense as in humans.
Speaker 2 (10:16):
Now, is there still any kind of like pushback from
I guess human exceptionalists that argue that animals can't non
human animals can't or don't demonstrate this kind of complexity.
Speaker 3 (10:28):
Well, not within I would say the scientific community. There
really isn't much of that pushback anymore. Initially there was
when people first began studying social networks and non humans.
Many people in who were animal behaviorists were leery that
the notion was that animals are complex and their societies
(10:51):
are complex. They're but they're not social network complex. That was,
you know, even in the early two thousands, They're There
was still some of that. I interviewed a bunch of
people for this book, and I had stories of people
telling me that in the early two thousands, when they
(11:11):
would put in grant applications to study social networks and
non humans, they would get this kind of pushback that was,
you know, it can't be this complex. You're you're, you're,
you're making it more complex than it needs to be,
and we're not ready to kind of give you money
to do this. But the more that people were able
to do it on their own, the more that it
(11:33):
became part and parcel of what people were looking for,
the less less the pushback. I mean, you're going to
get pushback from outside the scientific community, from people who
who just want to live in a world of human
exceptionalism that tends to fall apart eventually. I mean, you know,
(11:53):
we used to think that was true about tool use
in in in in animals, that you know, only humans
could use tools. Then we find that animals can use
tools only humans have culture. Well no, it turns out
animals have culture, only humans have social networks. No, in fact,
non humans have social networks. So the pushback is nowadays
(12:14):
not as bad as it used to be.
Speaker 2 (12:15):
I like that you mentioned the tool use. You know,
this is one of those areas where when we think
of toolse do some in animals that a lot of
people instantly think of. Examples involving say like chimpanzees or
or certain you know, birds come to mind. Especially when
we think of culturally transmitted tool use, we may think
of the chimpanzee example, but you discuss examples involving dolphins
(12:38):
and whales, can you describe the tools they seem to
be using.
Speaker 3 (12:43):
Sure. So there's this wonderful study on bottomnosed dolphins. It's
been going on in Australia in a place called Shark
Bay for the last thirty or forty years, and so
they know literally thousands of dolphins that are swimming around
in Shark Bay individually, and we've learned a tremendous amount
(13:05):
about how sort of culture, how complex they are socially.
But it wasn't until the last couple of decades that
this idea that tool use in dolphins was going on.
And in dolphins the tool is actually another living organism.
(13:26):
So basically what they do is they put a sponge
on the end of their their rostrum, their their their
face where where where their mouth is. They they put
this sponge over that when they're looking for food. And
the reason that they do that is that oftentimes they're
(13:48):
probing the bottom of the bay that's very rocky and
gravelly and it and it hurts to pound down on there.
And what they're doing is they're trying to find fish
that are hiding under the gravel and sand. So if
you stick soft sponge on top of your mouth, then
probing down there allows you much more flexibility and a
(14:10):
lot less pain. And it turns out that dolphins are
very particular about the sponges that they use. Once they
find one that works, they keep it for a long time.
So they'll go around probing on the bottom for food
and if they find a fish that's hidden, they drop
the sponge and they go and they catch that fish.
(14:30):
Then they come back and they look for the sponge
they had before it because if it worked once, it's
likely to work again. They pick it up, they put
it back well, they put it back onto their face,
and then they go looking for more things at sort
(14:50):
of hiding in the bottom of the sand. And they
learn this. They learn how to sponge from their mothers.
So if you watch calves, dolphin calves, they're basically learning
the technique of how to find a good sponge, put
it on, and hunt with it. And so the actual
learning is through mother child interaction. It's not genetic, but
(15:18):
it's rather they learn from their parents. Now in terms
of the networking. It's actually complex. So basically, when they
have these sponges on, they're hunting alone, and so you
wouldn't think that this sponging had anything to do with
social networks, but in fact it does. And the reason
(15:42):
that it does is dolphins often carry these sponges around
when they're not hunting because, as I say, if they
find a good sponge, they like it. Dolphins know who
else are spongers. Not everyone's a sponger, only a small
subset of them actually use these two tools. And so
what the researchers did was they started trying to understand
(16:06):
whether or not individuals who did use these sponge tools
hung out with each other when they actually weren't going
around looking for food, and it turns out they were.
There are these cliques of dolphins that use the sponge
tools that hang out with each other when they're not
actually down on the bottom looking for food. And the
(16:29):
reason we think they do this is if you hang
out with other spongers, you're likely to get information about
where the good places to sponge are, and so you
network with them so that you can take these sponges
and use them in the best possible locations, and the
(16:51):
sponges are really great tools. The ganet man who ran
this study, she and her colleagues actually thought, you know,
we should see if sponging really works. It kind of
looks like it works when you watch the dolphins. They
put sponges on their hands, and they went around under
the water using the sponges on their hands the way
(17:13):
dolphins use them on their snouts. And it turns out
you really do kick up a lot of prey items
things to eat when you use these sponges. And so
networking allowed us to kind of understand this cultural tool
use in a much more general way, not just this
(17:34):
dolphin does it or that dolphin does it, but that
they hang around together if they do it, and they
get all sorts of information from each other when they
do this.
Speaker 2 (17:43):
Wow, that's incredible.
Speaker 3 (17:44):
Yeah, no, it's a wonderful long term study of an
incredibly complex organism. I mean, dolphins. Everybody loves dolphins. Their
sociality is over the top in terms of the sorts
of things we typically see in nature.
Speaker 2 (18:10):
Now, in the book, you divide the chapters up by
specific networks and needs. You know, you alluded to this earlier,
you know, food reproduction, power, safety, travel, communication, health, and culture.
What areas were you either most surprised about or do
you think will be most surprising to readers in these chapters?
You know, because I feel like for a lot of
(18:30):
general readers, you know, we can easily think of non
human animals engaging in some level of like food reproduction
or power dynamics. You know, we've seen enough documentaries or
engage with enough animal content. But communication and health don't
always instantly come to mind, I imagine, not with like
the number of species that are covered in the book.
Speaker 3 (18:51):
Sure, yeah, so communication is a great one in terms
of the kinds of things that might surprise readers. There
is wonderful work that's been done on communication in chimpanzees,
for example. So in chimpanzees, when they're communicating with each other,
(19:15):
they can communicate in all sorts of different ways, and
some of those ways are much more visual, and some
of them are much more physical and tactile that involve touching.
And it turns out that again, social network thinking allows
us to probe really deep into these communication networks that
(19:42):
exist in chimpanzees. And so, for example, there's this population
of chimpanzees called the sun so population that's been studied
for a very long time, and it turns out that
when you look at the kind of gestural communication it
goes on in these chimpanzees, you see something very different
(20:05):
when individuals are interacting with friends in their social networks
rather than with others who they don't know quite as well.
So if you look at communication between chimpanzees who know
each other well and who have done things like cooperative
(20:25):
hunting together, they tend to use visual communication. And this
kind of visual communication. Other people have found that this
kind of really lowers their heart rates and reduces the
amount of stress that the chimpanzee itself feels. The individual
(20:48):
who's the recipient of the communication calms down, they have
a lower heart rate. This is when communication goes on
between friends. But when communication is going on between individuals
who don't know each other as well, maybe haven't interacted
as much in the past, then you tend to see
a different kind of communication. You tend to see it
(21:09):
being very physical and tactile, with them touching each other.
And the researchers who did this work, Anna and Sam
Roberts have argued that visual communication works perfectly well between
friends because you know each other and there's a large
level of trust that's already in place. But when you
don't know each other very well, visual communication doesn't work
(21:33):
as well because it's not as clear, it's.
Speaker 4 (21:35):
Not as as salient as auditory and tactile communication, where
you're really up front, right in the face of the
individual touching them.
Speaker 3 (21:47):
Then they can really understand what it is that you're
trying to communicate. And that's important because chimpanzee networks break
up and they come back together, and so when you're
interacting with individuals that you don't know very well, you
really want to make sure that your communication is clear.
And these kind of auditory and physical communication gestures are
(22:11):
much better at that. And so you see it among
individuals who don't know each other very well.
Speaker 2 (22:16):
Fascinating.
Speaker 3 (22:17):
But here's the thing, you know, so chimpanzees are our
closest living relatives and they have very large brains, right,
But you can go and find communication networks and honeybees
and a former student of mine has been studying that
in a research field station outside of London where they
(22:38):
have these experimental honeybee hives, and so in honeybees, the
primary way that they communicate is actually by something known
as the waggle dance. So here the bees are trying
to communicate to one another where a new food source is.
And the way that they typically do this is, if
(22:59):
you've a new food source and you go back to
the honeybee hive, you do this particular kind of dance
known as the waggle dance, and the waggle dance basically
involves moving very very quickly and shaking your abdomen as
you're moving through the hive. And we know from prior
(23:20):
work that this gives various types of information to others
in the hive about where the food source is. For example,
how long you dance gives information about how far away
the hive is, and there's a really nice translation. Every
tenth of a second of dancing translates into the food
being this many feet away from the hive. They also
(23:43):
dance at a certain angle, and the angle they dance at,
believe it or not, is the angle between the sun,
the hive and where the food is. So they're communicating
all of this information through the dance. Now, in terms
of working, it turns out that there were other ways
(24:03):
to communicate information about new food sources. They can communicate
this information when they transfer food from themselves to another
individual in the hive. They can also communicate information about
the food when they basically take their antennas and connect
(24:24):
to the antennas of another bee in the hive. This
also gives them information. So what has been done in
terms of the networking is people have asked, well, they
can get this information in all these different ways, how
do they do it? When do they decide if they're
going to transfer the information by dancing or moving food
(24:46):
from one mouth to another or touching antenna. So what
researchers did with they set up this experiment where they
had these hives that were placed out in a field
and they knew where the hives were, and they controlled
how much food was going into the hives. And what
they found was and so I should say, they marked
(25:08):
all of their bees, thousands of them, so they knew
who these bees were. And it turns out when you
look at communication networks and the bees, you find this
wonderfully complex system in place. If the sun is out there,
they use dancing to communicate because they can transfer information
(25:30):
about food using the angle of the sun compared to
the hive and the food source. But in London there
are many many days when it's not sunny, and when
it's not sunny, the communication network focuses on the transfer
of food or the touching of antenna. So they have
(25:50):
these kind of multiple communication networks and if one of
them is down because the sun isn't out, then they
move to a second kind of communication network. And so
what this tells us is that you know, you can
have a brain the size of a honeybee or the
brain the size of a chimpanzee, and you can still
(26:12):
get complex communication networks in non humans. You were also
asking about disease. I think for me this was one
of the more surprising components of social networks and animals,
the way that they relate to disease transmission. And here
(26:34):
what's kind of cool is that in almost all of
the other behaviors that we're talking about, feeding and communication
and cooperation, really it's individuals, animals and the network that
are the key. But when cut when it comes to disease,
what's basically going on is the disease is hitchhiking on
(26:56):
the social networks that the animals have in place. So
the animals don't want to transfer disease from one individual
to another, but the social networks are in place in
terms of, for example, aggression and power struggles. What that
means is diseases can use those networks to move from
(27:18):
one individual to another. And I think my favorite example
of this is this bizarre disease that has been studied
in Tasmanian devils. And if you can't picture a Tasmanian
devil in your head, think back to the Bugs Bunny cartoons,
because there was this wonderful caricature of a Tasmanian devil
(27:42):
in there. And in Tasmanian devils they have this thing
called facial tumor disease. And this is one of the
very rare instances that we know of in which cancer
is transmitted from one individual to another. The sort of
worst case scenario when we think about human cancers would
(28:05):
be if we could actually transmit cancer from one individual
to another. It doesn't happen, but in certain species, like
Tasmanian devils, it does. And what happens is if they
are infected with this cancer and they bite somebody really hard, right,
they can transmit that cancer to the other individual. So
(28:30):
here's where social networks come into play. Tasmanian Devils fight,
and they fight a lot, particularly during mating season. Males
will fight intensely to gain access to mates. Sometimes when
they fight, if you have facial tumor disease and you
bite somebody else, you can transfer that disease to that individual. Again,
(28:54):
the tumor is actually hitchhiking on the power show network
structure that's in place in the Tasmanian Devils. And so
it's not surprising, for example, that males transmit this disease
much more often to one another than females. And that's
because males fight a lot during mating season, and it's
(29:19):
only through bites that this disease can be transmitted. It's
more complex, and what we're discovering are strange things like
even though males are more likely to transmit the disease,
females also get facial tumor disease, and they tend to
get it from males who are defending them. But in
(29:42):
the context of courtships, sometimes it gets a little too
rough and you get some biting and females can get
infected with this disease. Now, what's weird is if you
look at female Tasmanian Devils. Usually it's individuals are in
the weakest health state that are most susceptible to getting disease.
(30:05):
But in the Tasmanian Devils, it's the healthiest females who
end up getting this cancerous disease by being bitten by males.
Why well, if you do a social network analysis, what
you find is the healthiest females are the ones that
the males prefer as mates. That means they're the ones
(30:28):
that are most likely to get bitten even unintentionally by
males during courtship. And so they the healthiest ones, end
up being most likely to get the cancer, which is
something that we can possibly have really understood without a
social network analysis.
Speaker 2 (30:47):
Wow, that's incredible. Yeah, I was going to ask about
the Tasmanian devil example. That one definitely stood out to
me when I was reading. Another one was the vampire bats.
Speaker 3 (30:56):
Oh. Yes, vampire bats are wonderful. They're a textbook example
of social behavior and in this case, cooperation. So let
me just tell you a little bit about what goes
(31:17):
on in the world of vampires. So, vampire bats do
in fact suck blood, right, but they don't suck human blood.
They suck the blood of cows and other kind of
domesticated species. And it turns out that if you're a
vampire bat, or if you're just a bat in general,
it's a really expensive way of living for a mammal. Right,
(31:40):
so bats are mammals, and most mammals don't fly, but
if you fly, it's energetically extremely expensive. And what people
have found is if a vampire bat doesn't get a
blood meal about every two days, it can starve to death. Now,
what the vampire bats do is they have this social
(32:04):
network in place where they transfer blood from one back
to the other. So if you take a camera and
you go inside a vampire bat roost, what you will
find sometimes is that one bat will come up to
another bat and it'll start licking its face in a
(32:24):
very kind of stereotypical manner. What that bat is doing
is it's trying to get the other bat to regurgitate
some of the blood that it has in its gut
so that the solicitor, the one that's licking the face,
can actually survive long enough to go out and get
its own blood meal. So it's hungry, it's starving. It
goes up to a bat that has a really distended
(32:47):
big gut, which means it has lots of blood. It
licks its face trying to get that bat to regurgitate
some of the blood to it. They will do that
for one another, but only when they know that it's
a trustworthy partner. So if one bat goes up to
another and tries to get blood regurgitated, the only way
(33:09):
it'll work is if in the past that blood that
bat who's hungry who needs the blood, has helped and
given blood to the bat that it's now asking for
blood from. So they're basically keeping track of who gave
them blood in the past when they were hungry, and
if that bat now comes up and tries to get
(33:30):
some blood you to recurgitate some blood, then you're much
more likely to do it. So that's the basic structure
that's in place in these vampire bat roots. Networking comes
into place because it turns out again that it really
matters not just sort of who gave you blood when
(33:50):
you were hungry, but also who you go at with
and look for blood when there's an nice night out
there to go out and fly and look for an
unsuspecting cow. So what researchers have done is they have
placed little what are known as pit tags on these bats.
(34:15):
And so basically all a pit tag is is this little, tiny,
one ounce less than one ounce device if they put
on a bat, and it allows them to track every
bat in the roost when the bat goes out and
looks for food. And the way it works is they
have all of these receivers that have been placed out
in the fields with the cows, and so you can
(34:36):
know where the bats are because the little things they
have on their bat are transmit are transmitting information to
these receivers that are in the field, so you know
everything about what the bats are doing. What's more, these
little pit tags that the bats have on their back
talk to each other. That is, if two vampire bats
(34:59):
come close enough to one another, these little pit tags
light up and you know that vampire Bat one and
vampire Bat two are on the back of a cow
together sucking blood. Now, these things are not easy to
set up, but after you have this system in place,
you can test all sorts of incredible things, like is
(35:21):
it the case that this kind of network of blood
sharing that goes on inside the roost translates into who's
hanging out with who? When they're actually going out and
looking for blood. That's a really hard thing to do
because you never know when bats are going to leave
their roost and they fly and they're really hard to follow.
But when you have these tags and these transmitters and
(35:44):
responders in the field, you can do this and lo
and behold. Basically, the network of blood sharing that goes
on inside the roost is a very good predictor of
who will be found on the back of the same
cow sucking blood when they go out. They go out,
The bats go out and start flying independently, but they
(36:05):
find their favorite partners one way or another, and they
end up tending to be found on the back of
some unsuspecting count in the field. And we can only
know how complex all of this is when we realize
that it's all embedded in these social networks that the
(36:26):
bats have built around blood sharing.
Speaker 2 (36:28):
Wow, that's incredible. And the technology that goes into these studies.
I was just floored by numerous examples in the book.
Speaker 3 (36:35):
Yeah, I mean, so the study of social networks and
animals has just absolutely exploded in part because of these
technological advances. So you have these talking sensors like I
just mentioned, to you where when the animals come close enough,
they both sensors light up and you know they're to
gather wherever they are. That's one thing. Then basically in
(37:00):
other studies, what they do, what individuals do, is they
attach the equivalent of kind of a GPS device to
the back of an animal and they can track it
then over really long distances. And my favorite example here
is white stork behavior. So white storks are these beautiful animals, right,
(37:24):
but they migrate thousands of miles in the winter, and
we know almost nothing about the details of their migration
because it's really hard to follow birds that are flying
a thousand feet above the ground and traveling thousands of miles.
But if you put GPS transponders on their back, then
(37:47):
you have the possibility of doing this. So people who
have worked with these white storks, Andrea Flack is a
researcher at the Max Planck Institute, So she put all
of she put these GPS trackers on the backs of
these white storks, and she basically would follow them as
(38:08):
they were making them migration. As I'm making them migration,
they kind of come down every night to rest, and
she would kind of try and track them for hundreds
of miles if she could on her own, and so
she was trying to follow them, but at the same time,
she could know what the birds were doing when they
were a thousand feet above the ground because the GPS
(38:32):
devices were so sensitive that she could know where a
bird was in the flock as they were flying these
thousands of miles. And it turns out that what that
allowed her to do was built a social network of
the flock as it was flying these south thousands of miles.
(38:53):
And what she found was that in this network, this
travel network, there were certain white storks that were the leaders.
They were the ones that were determining when the flock
would move this way or that way. So if you
look at a bird of flocks, a flock of birds
like geese, you can tell there are certain leaders that
(39:16):
are the ones that are determining the movement of the flock.
But you can't do that with white storks when they're
that far above the ground unless you have these GPS devices.
So there are these leaders and followers in the white
stalk travel networks, and it really matters. The leaders are
very very good at finding up drafts. So when you're
(39:39):
flying as a bird, what you want is to expend
as little energy as you can, and there are these updrafts,
these winds that come that allow you to fly at
very low energy levels. The leaders are tremendously good at
finding these, and in fact, what they were able to
do with the researcher were able to do was demonstrate
(40:02):
not just that there were leaders and followers in these flocks,
but that the leaders were actually able to migrate further
than the followers because they were so good at finding
these updrafts. So it really mattered who was a leader
and a follower in these networks. And this kind of
study would have been unthinkable twenty years ago. I mean,
(40:25):
without the technology, you simply cannot do this sort of thing.
You can move from flying one thousand meters above the
ground to swimming many many feet below the water and
find the same thing. And there's this wonderful study done
on manta rays in the South Pacific where they've done
(40:49):
exactly this. They've tagged them so they can study what
the manta rays are doing. And in addition to that,
they fly these drones over groups of mantar rays that
are swimming close to the water surface. The drones then
videotape the interactions between the manta rays. And the manta
(41:11):
rays have these sort of very unique color and patterns
that allow the researchers to know who's who. So you
can study them by the drones watching them from above,
and the little pit tags and various other GPS like
devices under the water. They'll let you know where they
(41:33):
are all the time, which means you can build social
networks you can look at In the case of the
manta rays, they look at who's a key hub in
a social network. So a key hub is an individual
through which a lot of information travels. So if you
think about Facebook, for example, key hubs are like public
(41:57):
figures where if you want to sort of track the
way that information flows, these individuals really matter. Well, it
turns out in manta rays there are key hubs as well,
individuals through which information travels. In this case, it turns
out that juvenile manta rays are the hubs in social
networks associated with feeding. They're the ones that are the
(42:21):
key to understanding how individuals swim around looking for food underwater. Again,
without the technology, these are just pipe dreams, but now
they are going on. All these kind of studies are
going on all the time in non humens.
Speaker 2 (42:38):
It's also fascinating. And again we've only been able to
really touch on some of the examples from the book.
The book is loaded with excellent examples and fascinating tibots
about the methodology and technology that goes into studying them.
(42:59):
In the word of the book, you write that quote,
it's time to scratch off another item from the what
makes humans unique? List? So I thought I was just wondering.
You know, obviously the book is primarily about what we're
learning about these non human animals and their social networks.
But do you think to any degree you were able
to like turn some of these revelations around to better
(43:19):
understand like what human social networks are? You have only
just to remind us that we're not special.
Speaker 3 (43:27):
Yeah, so I think at the most general level, it
does remind us that we're not special. And yet another way,
so we talked about tools and culture were things that
we used to think we were unique, and we're not.
We're not unique in social networks. But in terms of
like perhaps the lessons that we can learn by studying
social networks and non humans, I think there is some
(43:49):
you know, you always have to be careful when you
do this sort of thing. But let me give you
just one example that I think helps in terms of
what we might learn. So there's this great study that
was done on Reese's macaque monkeys and their social networks
on this little island in Puerto Rico. And I won't
(44:12):
get into the details of the social network study per se,
but basically the thing about this study was that they
had been studying these macaques on the island for a
very long time. They knew a lot about their social networks.
Then Hurricane Maria came through and absolutely devastated the island
(44:33):
where these mecacus lived. And obviously it also decimated Puerto
Rico and had all sorts of impacts on our own species,
but it basically destroyed the island that they lived on,
the mecacs lived on, and what that allowed the researchers
to do was study how social networks respond to disasters.
(44:57):
This kind of study was also done in in mice,
how they respond to catastrophic events, social networks respond to
catastrophic events. I think that the more information we get
that on that from non humans, the more we might
be able to understand ways that we might expect social
(45:20):
networks to respond to natural disasters in our own species.
One thing that I think studies and animal behavior allow
us to do is this, If really your primary interest,
and it's perfectly reasonable, would be social networks and non humans,
and you're not all that interested in social networks and
(45:42):
non humans, here's a reason you might want to rethink that.
If you think about this at the species level, we
have a species count of one if we only focus
on humans. But if these social networks are as complex
as they appear to be in non humans, that means
(46:04):
that we have this treasure chest of information about how
social networks work. How does a what does it mean
to be a hub in a social network? How much
does it matter what your friends do versus what your
friends of friends do. It turns out friends of friends
really matter not in non human social networks. How do
(46:26):
these things work? At a most general level, we're if
we only think about humans, our sample sizes one species.
But if we think about it in dolphins and humpback
whales and and manter rays and honey bees and chimpanzees
and so many other species, then all of a sudden,
maybe we can pick up some patterns about social networks
(46:48):
that we wouldn't have picked up otherwise, and so I
think that that's potentially a very powerful implication of studying
this in non humans.
Speaker 2 (46:57):
Yeah, absolutely fascinating. I have one last question that relates
to an earlier book that you wrote was two thousand
and nine, Mister Jefferson and the Giant Moose, Natural History
in Early America. I was not familiar with the history
referenced in the title, as if nothing else, is just
a teaser for listeners who might be interested, Could you
(47:19):
just briefly tell us why Thomas Jefferson was obsessed with
a giant moose?
Speaker 3 (47:25):
Sure? What had happened was the world's leading naturalists in France,
a guy by the name of Count Bufon, had written
this giant encyclopedia of natural history, and one of the
things that he did in an encyclopedia was promote this
idea called the degeneration hypothesis. And what this natural historian
(47:48):
said was that all life in the New World, particularly
in America, was degenerate compared to life other places, that
all the animals in in the United States or even
before that, the colonies were weak, feeble, and diminished compared
to species in other places in the world, and Jefferson
(48:12):
became obsessed in demonstrating to Count Buffon why he was wrong.
In fact, the longest chapter in the book, the only
book that Jefferson ever wrote, The Notes on the State
of Virginia, is all about proving how wrong this degeneracy
hypothesis is. And one of the key pieces of information
(48:33):
that he wanted Buffon to see was our moose, which
was it's massive right. So Jefferson wanted to send Buffon
a giant moose to show him how wrong he was
about this theory of American degeneracy. And so he spent
an extraordinary amount of time and effort getting this moose
(48:54):
and then shipping it over to Buffon. And so that's
where the moose in the title comes from.
Speaker 2 (48:59):
Fascinating. I'm going to I'm gonna have to put this
on my to read list. I was instantly fascinated.
Speaker 3 (49:04):
Oh, thank you, Yeah, I mean, it was a tremendously
fun project.
Speaker 2 (49:07):
Well, Lee, thanks again for coming on the show. The
new book, The Well Connected Animals, Social Networks and the
Wondrous Complexity of Animal Societies is out this week, so
encourage all of our listeners to go check that out.
Speaker 3 (49:20):
Thank you so much for having me. I enjoyed you
very much.
Speaker 2 (49:24):
Thanks once more to Lee Alan Dugatkin for taking time
out of his day to chat with me about the
new book. That new book, again is The Well Connected
Animal Social Networks and the Wondrous Complexity of Animal Societies.
It is out this Thursday, so go grab yourself a copy.
Thanks as always to the excellent JJ Possway for producing
(49:47):
this episode and if you would like to get in
touch with Joe or myself, if you have suggestions for
future episodes of Stuff to Blow Your Mind, If you
have interview suggestions you'd like us to consider, write and
we would love to hear from you. You can email us
at contact at stuff to blow your Mind dot com.
Speaker 1 (50:12):
Stuff to Blow Your Mind is production of iHeartRadio. For
more podcasts from my heart Radio, visit the iHeartRadio app,
Apple Podcasts, or wherever you listen to your favorite shows.
Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 2 (00:13):
Hey, welcome to Stuff to Blow Your Mind. My name
is Robert Lamb. Today I have an interview episode for you.
I recently spoke with Lee Alan Dugatkin, a professor of
evolution and behavior at the University of Louisville in Kentucky.
He is the author of the new book The Well
Connected Animal Social Networks and the Wondrous Complexity of Animal Societies.
(00:37):
This book comes out this Thursday, so wherever you get
your books, in whatever formats, you can probably go ahead
and pre order it. If not, grab it on Thursday.
It's a delightful read. And this was a delightful chat.
I really enjoyed talking with Lee. Let's go ahead and
jump right into the interview.
Speaker 3 (00:59):
Hi.
Speaker 2 (00:59):
Lee, welcome to the show.
Speaker 3 (01:00):
Thank you for having me. I've been looking forward to it.
Speaker 2 (01:03):
So you're an evolutionary biologist, an historian of science, and
an animal behaviorist. How do these classifications triangulate on your
work and how did you get involved in your field?
Speaker 3 (01:13):
Yeah, so I got involved in a sort of circuitous way.
I really didn't know what I wanted to do, even
when I was in college. I happened upon the study
of animal behavior and evolution, and a friend of mine
mentioned a book he was reading, and before I knew it,
(01:33):
I was in graduate school studying evolution and behavior and
non humans because I just fell in love with the
topic and I thought it was sort of the ultimate
kinds of questions one could ask about life on the planet.
And so early on a lot of my work was
experimental work with animals. I looked at the evolution of
(01:53):
cooperation and the evolution of aggression and so on for
many many years in my laboratory. And then about fifteen
years ago or so, after I had been doing this
for a couple of decades, I started getting much more
interested in the history of the subjects that I was
(02:13):
working on. So it turns out that all of the
people early on who were studying the evolution of cooperation
were really fascinating characters in and of themselves, how they
came about it, the environment, and the kind of social
atmosphere in which they developed their ideas. And I began
to become much more interested in that aspect of the work.
Speaker 2 (02:36):
And so.
Speaker 3 (02:39):
All these areas dovetail in the sense that I still
do work on studying evolution and animal behavior. But I
also have had this component of it's worth stopping for
a minute and realizing that, you know, in the late
eighteen hundreds or something like that, here's how these ideas
came about. Here are the people who did it, and
(03:00):
here's the kind of social environment in which it happened.
And I think it makes the study of science itself
much richer to do it that way.
Speaker 2 (03:08):
The new book is The Well Connected Animals, Social Networks
and the Wondrous Complexity of Animal Societies. Could you walk
us through what a social network is and say sociology
and anthropology and how and when the concept enters into
contemplation of non human animals.
Speaker 3 (03:25):
Sure, And you know, I should say that there are
many many different definitions of social networks, depending on exactly
what discipline you're interested in and how mathematical you want
to get for me, and I think from I think
this is a reasonable general definition. Is a social network
(03:46):
is just a group of individuals through which information travels,
And it may travel directly and it may travel indirectly.
And it's also a group of individuals who somehow are
other affect one another in a real way. And again
that could happen either directly by your interaction with Steve,
(04:10):
or it could happen indirectly because you interact with Steve,
and Steve interacts with Nancy, and so Nancy is affected
by what you have done to Steve. And so generally
it's this information flow and effect on others in your network.
That's that for me, is the key to social networks.
(04:34):
You know, humans are in all sorts of social networks,
Facebook and that sort of thing, but we're also embedded
in them in almost everything we do in life. Are
our families or one kind of social network? Are the
people we work with or another, our friends or another,
and so on, and they all overlap. Now, in terms
(04:55):
of the history of the subject, I mean, anthropologists and
particularly sociologists have been interested in this in humans for
quite some time. It was, you know, in the nineteen
forties and nineteen fifties where people first began to get
(05:15):
serious about trying to understand the details of what we
now would refer to as social networks how they work
in humans. And that involved a lot of mathematics in
terms of understanding what it means if I interact with you,
(05:37):
and you interact with somebody else and that somebody else
is affected by me, and who is Who are the
key individuals in the social network, the ones that have
the most impact, and are there cliques where certain individuals
tend to interact with each other more? And that really
began to flourish, I would say, in the nineteen forties
(05:59):
and fifties in anthropology and sociology what we now refer
to as a social network. I think that language became
much more common in the late nineteen hundreds and into
the early two thousands. Now when it comes to studying
(06:21):
social networks and non humans, we can trace it back
quite far in the sense that even in Darwindnesday and
a little bit later, so the late eighteen hundreds, people
were beginning to think that the same kind of social
tools that can be used to study human behavior can
(06:44):
be used to study animal behavior. And so there are
people who were basically arguing that animal societies were structured
very much like human societies. And even though the word
social network wasn't around, the idea idea that we could
study non humans like we study humans was there. It
(07:05):
really began to flourish more again around the same time
as early work in humans did. That is, in this
case maybe the nineteen fifties and nineteen sixties when primatologists
people who study monkeys and apes, began to think in
terms of social networks. They began to realize that information
(07:29):
was flowing through these non human groups, again mostly primates,
in a way that was similar to the way it
flows through human groups. And it really mattered in a
group of chimpanzees, if one chimpanzee groomed the other and
got bugs and parasites off it back, it really mattered
(07:50):
who they groomed and who that individual groomed, and how
that kind of grooming social network developed. So it first
started with non human primates, which kind of makes sense
because there are closest evolutionary relatives, and then it began
to branch out in the nineteen eighties and nineteen nineties
(08:12):
when people began to study it in all sorts of organisms.
In fact, the two classic studies early on were done
in dolphins and in birds. So it's been around in
a serious way in the animal behavior literature for on
the order of twenty to thirty years. Now.
Speaker 2 (08:32):
Okay, so the roots go back a bit deeper, but
it's really taken off in recent decades.
Speaker 3 (08:38):
Absolutely, absolutely in fact, right now, the study of social
networks in non humans is probably is one of the
most active areas in the entire field. I mean, anytime
you open up a journal on behavior and non humans,
you're likely to find an article about social networks. And
those networks are important in almost every context for non humans.
(09:00):
There are networks about feeding, there are mating networks, there
are traveling networks, there are cooperation networks, there are power networks.
Everywhere you look. Now that we've started to actually explore
it in depth, we're finding it. And this is sort
of what happens in animal behavior a lot. We tend
to think of things initially as strictly human, and then
(09:22):
when we begin to probe deeper, we see similar sorts
of things in non humans, and once we begin to look,
we begin to see it everywhere.
Speaker 2 (09:30):
And to be clear, with humans, we're talking about multiple
social networks being in place for a given individual or
a given group. But the same is true of these
various animal examples as well. Right, We're not talking about
just like the social network of the macaque. We're talking
about like the multiple interconnected social networks.
Speaker 3 (09:49):
Right, absolutely, So it might be that you're studying networks
in the sense of who's going around feeding with who,
and who's sharing food with who. But in that same species,
you might be looking at who's being aggressive towards who,
and who's traveling together, and who's being nice to who,
(10:11):
and all of those are overlapping networks in the same
sense as in humans.
Speaker 2 (10:16):
Now, is there still any kind of like pushback from
I guess human exceptionalists that argue that animals can't non
human animals can't or don't demonstrate this kind of complexity.
Speaker 3 (10:28):
Well, not within I would say the scientific community. There
really isn't much of that pushback anymore. Initially there was
when people first began studying social networks and non humans.
Many people in who were animal behaviorists were leery that
the notion was that animals are complex and their societies
(10:51):
are complex. They're but they're not social network complex. That was,
you know, even in the early two thousands, They're There
was still some of that. I interviewed a bunch of
people for this book, and I had stories of people
telling me that in the early two thousands, when they
(11:11):
would put in grant applications to study social networks and
non humans, they would get this kind of pushback that was,
you know, it can't be this complex. You're you're, you're,
you're making it more complex than it needs to be,
and we're not ready to kind of give you money
to do this. But the more that people were able
to do it on their own, the more that it
(11:33):
became part and parcel of what people were looking for,
the less less the pushback. I mean, you're going to
get pushback from outside the scientific community, from people who
who just want to live in a world of human
exceptionalism that tends to fall apart eventually. I mean, you know,
(11:53):
we used to think that was true about tool use
in in in in animals, that you know, only humans
could use tools. Then we find that animals can use
tools only humans have culture. Well no, it turns out
animals have culture, only humans have social networks. No, in fact,
non humans have social networks. So the pushback is nowadays
(12:14):
not as bad as it used to be.
Speaker 2 (12:15):
I like that you mentioned the tool use. You know,
this is one of those areas where when we think
of toolse do some in animals that a lot of
people instantly think of. Examples involving say like chimpanzees or
or certain you know, birds come to mind. Especially when
we think of culturally transmitted tool use, we may think
of the chimpanzee example, but you discuss examples involving dolphins
(12:38):
and whales, can you describe the tools they seem to
be using.
Speaker 3 (12:43):
Sure. So there's this wonderful study on bottomnosed dolphins. It's
been going on in Australia in a place called Shark
Bay for the last thirty or forty years, and so
they know literally thousands of dolphins that are swimming around
in Shark Bay individually, and we've learned a tremendous amount
(13:05):
about how sort of culture, how complex they are socially.
But it wasn't until the last couple of decades that
this idea that tool use in dolphins was going on.
And in dolphins the tool is actually another living organism.
(13:26):
So basically what they do is they put a sponge
on the end of their their rostrum, their their their
face where where where their mouth is. They they put
this sponge over that when they're looking for food. And
the reason that they do that is that oftentimes they're
(13:48):
probing the bottom of the bay that's very rocky and
gravelly and it and it hurts to pound down on there.
And what they're doing is they're trying to find fish
that are hiding under the gravel and sand. So if
you stick soft sponge on top of your mouth, then
probing down there allows you much more flexibility and a
(14:10):
lot less pain. And it turns out that dolphins are
very particular about the sponges that they use. Once they
find one that works, they keep it for a long time.
So they'll go around probing on the bottom for food
and if they find a fish that's hidden, they drop
the sponge and they go and they catch that fish.
(14:30):
Then they come back and they look for the sponge
they had before it because if it worked once, it's
likely to work again. They pick it up, they put
it back well, they put it back onto their face,
and then they go looking for more things at sort
(14:50):
of hiding in the bottom of the sand. And they
learn this. They learn how to sponge from their mothers.
So if you watch calves, dolphin calves, they're basically learning
the technique of how to find a good sponge, put
it on, and hunt with it. And so the actual
learning is through mother child interaction. It's not genetic, but
(15:18):
it's rather they learn from their parents. Now in terms
of the networking. It's actually complex. So basically, when they
have these sponges on, they're hunting alone, and so you
wouldn't think that this sponging had anything to do with
social networks, but in fact it does. And the reason
(15:42):
that it does is dolphins often carry these sponges around
when they're not hunting because, as I say, if they
find a good sponge, they like it. Dolphins know who
else are spongers. Not everyone's a sponger, only a small
subset of them actually use these two tools. And so
what the researchers did was they started trying to understand
(16:06):
whether or not individuals who did use these sponge tools
hung out with each other when they actually weren't going
around looking for food, and it turns out they were.
There are these cliques of dolphins that use the sponge
tools that hang out with each other when they're not
actually down on the bottom looking for food. And the
(16:29):
reason we think they do this is if you hang
out with other spongers, you're likely to get information about
where the good places to sponge are, and so you
network with them so that you can take these sponges
and use them in the best possible locations, and the
(16:51):
sponges are really great tools. The ganet man who ran
this study, she and her colleagues actually thought, you know,
we should see if sponging really works. It kind of
looks like it works when you watch the dolphins. They
put sponges on their hands, and they went around under
the water using the sponges on their hands the way
(17:13):
dolphins use them on their snouts. And it turns out
you really do kick up a lot of prey items
things to eat when you use these sponges. And so
networking allowed us to kind of understand this cultural tool
use in a much more general way, not just this
(17:34):
dolphin does it or that dolphin does it, but that
they hang around together if they do it, and they
get all sorts of information from each other when they
do this.
Speaker 2 (17:43):
Wow, that's incredible.
Speaker 3 (17:44):
Yeah, no, it's a wonderful long term study of an
incredibly complex organism. I mean, dolphins. Everybody loves dolphins. Their
sociality is over the top in terms of the sorts
of things we typically see in nature.
Speaker 2 (18:10):
Now, in the book, you divide the chapters up by
specific networks and needs. You know, you alluded to this earlier,
you know, food reproduction, power, safety, travel, communication, health, and culture.
What areas were you either most surprised about or do
you think will be most surprising to readers in these chapters?
You know, because I feel like for a lot of
(18:30):
general readers, you know, we can easily think of non
human animals engaging in some level of like food reproduction
or power dynamics. You know, we've seen enough documentaries or
engage with enough animal content. But communication and health don't
always instantly come to mind, I imagine, not with like
the number of species that are covered in the book.
Speaker 3 (18:51):
Sure, yeah, so communication is a great one in terms
of the kinds of things that might surprise readers. There
is wonderful work that's been done on communication in chimpanzees,
for example. So in chimpanzees, when they're communicating with each other,
(19:15):
they can communicate in all sorts of different ways, and
some of those ways are much more visual, and some
of them are much more physical and tactile that involve touching.
And it turns out that again, social network thinking allows
us to probe really deep into these communication networks that
(19:42):
exist in chimpanzees. And so, for example, there's this population
of chimpanzees called the sun so population that's been studied
for a very long time, and it turns out that
when you look at the kind of gestural communication it
goes on in these chimpanzees, you see something very different
(20:05):
when individuals are interacting with friends in their social networks
rather than with others who they don't know quite as well.
So if you look at communication between chimpanzees who know
each other well and who have done things like cooperative
(20:25):
hunting together, they tend to use visual communication. And this
kind of visual communication. Other people have found that this
kind of really lowers their heart rates and reduces the
amount of stress that the chimpanzee itself feels. The individual
(20:48):
who's the recipient of the communication calms down, they have
a lower heart rate. This is when communication goes on
between friends. But when communication is going on between individuals
who don't know each other as well, maybe haven't interacted
as much in the past, then you tend to see
a different kind of communication. You tend to see it
(21:09):
being very physical and tactile, with them touching each other.
And the researchers who did this work, Anna and Sam
Roberts have argued that visual communication works perfectly well between
friends because you know each other and there's a large
level of trust that's already in place. But when you
don't know each other very well, visual communication doesn't work
(21:33):
as well because it's not as clear, it's.
Speaker 4 (21:35):
Not as as salient as auditory and tactile communication, where
you're really up front, right in the face of the
individual touching them.
Speaker 3 (21:47):
Then they can really understand what it is that you're
trying to communicate. And that's important because chimpanzee networks break
up and they come back together, and so when you're
interacting with individuals that you don't know very well, you
really want to make sure that your communication is clear.
And these kind of auditory and physical communication gestures are
(22:11):
much better at that. And so you see it among
individuals who don't know each other very well.
Speaker 2 (22:16):
Fascinating.
Speaker 3 (22:17):
But here's the thing, you know, so chimpanzees are our
closest living relatives and they have very large brains, right,
But you can go and find communication networks and honeybees
and a former student of mine has been studying that
in a research field station outside of London where they
(22:38):
have these experimental honeybee hives, and so in honeybees, the
primary way that they communicate is actually by something known
as the waggle dance. So here the bees are trying
to communicate to one another where a new food source is.
And the way that they typically do this is, if
(22:59):
you've a new food source and you go back to
the honeybee hive, you do this particular kind of dance
known as the waggle dance, and the waggle dance basically
involves moving very very quickly and shaking your abdomen as
you're moving through the hive. And we know from prior
(23:20):
work that this gives various types of information to others
in the hive about where the food source is. For example,
how long you dance gives information about how far away
the hive is, and there's a really nice translation. Every
tenth of a second of dancing translates into the food
being this many feet away from the hive. They also
(23:43):
dance at a certain angle, and the angle they dance at,
believe it or not, is the angle between the sun,
the hive and where the food is. So they're communicating
all of this information through the dance. Now, in terms
of working, it turns out that there were other ways
(24:03):
to communicate information about new food sources. They can communicate
this information when they transfer food from themselves to another
individual in the hive. They can also communicate information about
the food when they basically take their antennas and connect
(24:24):
to the antennas of another bee in the hive. This
also gives them information. So what has been done in
terms of the networking is people have asked, well, they
can get this information in all these different ways, how
do they do it? When do they decide if they're
going to transfer the information by dancing or moving food
(24:46):
from one mouth to another or touching antenna. So what
researchers did with they set up this experiment where they
had these hives that were placed out in a field
and they knew where the hives were, and they controlled
how much food was going into the hives. And what
they found was and so I should say, they marked
(25:08):
all of their bees, thousands of them, so they knew
who these bees were. And it turns out when you
look at communication networks and the bees, you find this
wonderfully complex system in place. If the sun is out there,
they use dancing to communicate because they can transfer information
(25:30):
about food using the angle of the sun compared to
the hive and the food source. But in London there
are many many days when it's not sunny, and when
it's not sunny, the communication network focuses on the transfer
of food or the touching of antenna. So they have
(25:50):
these kind of multiple communication networks and if one of
them is down because the sun isn't out, then they
move to a second kind of communication network. And so
what this tells us is that you know, you can
have a brain the size of a honeybee or the
brain the size of a chimpanzee, and you can still
(26:12):
get complex communication networks in non humans. You were also
asking about disease. I think for me this was one
of the more surprising components of social networks and animals,
the way that they relate to disease transmission. And here
(26:34):
what's kind of cool is that in almost all of
the other behaviors that we're talking about, feeding and communication
and cooperation, really it's individuals, animals and the network that
are the key. But when cut when it comes to disease,
what's basically going on is the disease is hitchhiking on
(26:56):
the social networks that the animals have in place. So
the animals don't want to transfer disease from one individual
to another, but the social networks are in place in
terms of, for example, aggression and power struggles. What that
means is diseases can use those networks to move from
(27:18):
one individual to another. And I think my favorite example
of this is this bizarre disease that has been studied
in Tasmanian devils. And if you can't picture a Tasmanian
devil in your head, think back to the Bugs Bunny cartoons,
because there was this wonderful caricature of a Tasmanian devil
(27:42):
in there. And in Tasmanian devils they have this thing
called facial tumor disease. And this is one of the
very rare instances that we know of in which cancer
is transmitted from one individual to another. The sort of
worst case scenario when we think about human cancers would
(28:05):
be if we could actually transmit cancer from one individual
to another. It doesn't happen, but in certain species, like
Tasmanian devils, it does. And what happens is if they
are infected with this cancer and they bite somebody really hard, right,
they can transmit that cancer to the other individual. So
(28:30):
here's where social networks come into play. Tasmanian Devils fight,
and they fight a lot, particularly during mating season. Males
will fight intensely to gain access to mates. Sometimes when
they fight, if you have facial tumor disease and you
bite somebody else, you can transfer that disease to that individual. Again,
(28:54):
the tumor is actually hitchhiking on the power show network
structure that's in place in the Tasmanian Devils. And so
it's not surprising, for example, that males transmit this disease
much more often to one another than females. And that's
because males fight a lot during mating season, and it's
(29:19):
only through bites that this disease can be transmitted. It's
more complex, and what we're discovering are strange things like
even though males are more likely to transmit the disease,
females also get facial tumor disease, and they tend to
get it from males who are defending them. But in
(29:42):
the context of courtships, sometimes it gets a little too
rough and you get some biting and females can get
infected with this disease. Now, what's weird is if you
look at female Tasmanian Devils. Usually it's individuals are in
the weakest health state that are most susceptible to getting disease.
(30:05):
But in the Tasmanian Devils, it's the healthiest females who
end up getting this cancerous disease by being bitten by males.
Why well, if you do a social network analysis, what
you find is the healthiest females are the ones that
the males prefer as mates. That means they're the ones
(30:28):
that are most likely to get bitten even unintentionally by
males during courtship. And so they the healthiest ones, end
up being most likely to get the cancer, which is
something that we can possibly have really understood without a
social network analysis.
Speaker 2 (30:47):
Wow, that's incredible. Yeah, I was going to ask about
the Tasmanian devil example. That one definitely stood out to
me when I was reading. Another one was the vampire bats.
Speaker 3 (30:56):
Oh. Yes, vampire bats are wonderful. They're a textbook example
of social behavior and in this case, cooperation. So let
me just tell you a little bit about what goes
(31:17):
on in the world of vampires. So, vampire bats do
in fact suck blood, right, but they don't suck human blood.
They suck the blood of cows and other kind of
domesticated species. And it turns out that if you're a
vampire bat, or if you're just a bat in general,
it's a really expensive way of living for a mammal. Right,
(31:40):
so bats are mammals, and most mammals don't fly, but
if you fly, it's energetically extremely expensive. And what people
have found is if a vampire bat doesn't get a
blood meal about every two days, it can starve to death. Now,
what the vampire bats do is they have this social
(32:04):
network in place where they transfer blood from one back
to the other. So if you take a camera and
you go inside a vampire bat roost, what you will
find sometimes is that one bat will come up to
another bat and it'll start licking its face in a
(32:24):
very kind of stereotypical manner. What that bat is doing
is it's trying to get the other bat to regurgitate
some of the blood that it has in its gut
so that the solicitor, the one that's licking the face,
can actually survive long enough to go out and get
its own blood meal. So it's hungry, it's starving. It
goes up to a bat that has a really distended
(32:47):
big gut, which means it has lots of blood. It
licks its face trying to get that bat to regurgitate
some of the blood to it. They will do that
for one another, but only when they know that it's
a trustworthy partner. So if one bat goes up to
another and tries to get blood regurgitated, the only way
(33:09):
it'll work is if in the past that blood that
bat who's hungry who needs the blood, has helped and
given blood to the bat that it's now asking for
blood from. So they're basically keeping track of who gave
them blood in the past when they were hungry, and
if that bat now comes up and tries to get
(33:30):
some blood you to recurgitate some blood, then you're much
more likely to do it. So that's the basic structure
that's in place in these vampire bat roots. Networking comes
into place because it turns out again that it really
matters not just sort of who gave you blood when
(33:50):
you were hungry, but also who you go at with
and look for blood when there's an nice night out
there to go out and fly and look for an
unsuspecting cow. So what researchers have done is they have
placed little what are known as pit tags on these bats.
(34:15):
And so basically all a pit tag is is this little, tiny,
one ounce less than one ounce device if they put
on a bat, and it allows them to track every
bat in the roost when the bat goes out and
looks for food. And the way it works is they
have all of these receivers that have been placed out
in the fields with the cows, and so you can
(34:36):
know where the bats are because the little things they
have on their bat are transmit are transmitting information to
these receivers that are in the field, so you know
everything about what the bats are doing. What's more, these
little pit tags that the bats have on their back
talk to each other. That is, if two vampire bats
(34:59):
come close enough to one another, these little pit tags
light up and you know that vampire Bat one and
vampire Bat two are on the back of a cow
together sucking blood. Now, these things are not easy to
set up, but after you have this system in place,
you can test all sorts of incredible things, like is
(35:21):
it the case that this kind of network of blood
sharing that goes on inside the roost translates into who's
hanging out with who? When they're actually going out and
looking for blood. That's a really hard thing to do
because you never know when bats are going to leave
their roost and they fly and they're really hard to follow.
But when you have these tags and these transmitters and
(35:44):
responders in the field, you can do this and lo
and behold. Basically, the network of blood sharing that goes
on inside the roost is a very good predictor of
who will be found on the back of the same
cow sucking blood when they go out. They go out,
The bats go out and start flying independently, but they
(36:05):
find their favorite partners one way or another, and they
end up tending to be found on the back of
some unsuspecting count in the field. And we can only
know how complex all of this is when we realize
that it's all embedded in these social networks that the
(36:26):
bats have built around blood sharing.
Speaker 2 (36:28):
Wow, that's incredible. And the technology that goes into these studies.
I was just floored by numerous examples in the book.
Speaker 3 (36:35):
Yeah, I mean, so the study of social networks and
animals has just absolutely exploded in part because of these
technological advances. So you have these talking sensors like I
just mentioned, to you where when the animals come close enough,
they both sensors light up and you know they're to
gather wherever they are. That's one thing. Then basically in
(37:00):
other studies, what they do, what individuals do, is they
attach the equivalent of kind of a GPS device to
the back of an animal and they can track it
then over really long distances. And my favorite example here
is white stork behavior. So white storks are these beautiful animals, right,
(37:24):
but they migrate thousands of miles in the winter, and
we know almost nothing about the details of their migration
because it's really hard to follow birds that are flying
a thousand feet above the ground and traveling thousands of miles.
But if you put GPS transponders on their back, then
(37:47):
you have the possibility of doing this. So people who
have worked with these white storks, Andrea Flack is a
researcher at the Max Planck Institute, So she put all
of she put these GPS trackers on the backs of
these white storks, and she basically would follow them as
(38:08):
they were making them migration. As I'm making them migration,
they kind of come down every night to rest, and
she would kind of try and track them for hundreds
of miles if she could on her own, and so
she was trying to follow them, but at the same time,
she could know what the birds were doing when they
were a thousand feet above the ground because the GPS
(38:32):
devices were so sensitive that she could know where a
bird was in the flock as they were flying these
thousands of miles. And it turns out that what that
allowed her to do was built a social network of
the flock as it was flying these south thousands of miles.
(38:53):
And what she found was that in this network, this
travel network, there were certain white storks that were the leaders.
They were the ones that were determining when the flock
would move this way or that way. So if you
look at a bird of flocks, a flock of birds
like geese, you can tell there are certain leaders that
(39:16):
are the ones that are determining the movement of the flock.
But you can't do that with white storks when they're
that far above the ground unless you have these GPS devices.
So there are these leaders and followers in the white
stalk travel networks, and it really matters. The leaders are
very very good at finding up drafts. So when you're
(39:39):
flying as a bird, what you want is to expend
as little energy as you can, and there are these updrafts,
these winds that come that allow you to fly at
very low energy levels. The leaders are tremendously good at
finding these, and in fact, what they were able to
do with the researcher were able to do was demonstrate
(40:02):
not just that there were leaders and followers in these flocks,
but that the leaders were actually able to migrate further
than the followers because they were so good at finding
these updrafts. So it really mattered who was a leader
and a follower in these networks. And this kind of
study would have been unthinkable twenty years ago. I mean,
(40:25):
without the technology, you simply cannot do this sort of thing.
You can move from flying one thousand meters above the
ground to swimming many many feet below the water and
find the same thing. And there's this wonderful study done
on manta rays in the South Pacific where they've done
(40:49):
exactly this. They've tagged them so they can study what
the manta rays are doing. And in addition to that,
they fly these drones over groups of mantar rays that
are swimming close to the water surface. The drones then
videotape the interactions between the manta rays. And the manta
(41:11):
rays have these sort of very unique color and patterns
that allow the researchers to know who's who. So you
can study them by the drones watching them from above,
and the little pit tags and various other GPS like
devices under the water. They'll let you know where they
(41:33):
are all the time, which means you can build social
networks you can look at In the case of the
manta rays, they look at who's a key hub in
a social network. So a key hub is an individual
through which a lot of information travels. So if you
think about Facebook, for example, key hubs are like public
(41:57):
figures where if you want to sort of track the
way that information flows, these individuals really matter. Well, it
turns out in manta rays there are key hubs as well,
individuals through which information travels. In this case, it turns
out that juvenile manta rays are the hubs in social
networks associated with feeding. They're the ones that are the
(42:21):
key to understanding how individuals swim around looking for food underwater. Again,
without the technology, these are just pipe dreams, but now
they are going on. All these kind of studies are
going on all the time in non humens.
Speaker 2 (42:38):
It's also fascinating. And again we've only been able to
really touch on some of the examples from the book.
The book is loaded with excellent examples and fascinating tibots
about the methodology and technology that goes into studying them.
(42:59):
In the word of the book, you write that quote,
it's time to scratch off another item from the what
makes humans unique? List? So I thought I was just wondering.
You know, obviously the book is primarily about what we're
learning about these non human animals and their social networks.
But do you think to any degree you were able
to like turn some of these revelations around to better
(43:19):
understand like what human social networks are? You have only
just to remind us that we're not special.
Speaker 3 (43:27):
Yeah, so I think at the most general level, it
does remind us that we're not special. And yet another way,
so we talked about tools and culture were things that
we used to think we were unique, and we're not.
We're not unique in social networks. But in terms of
like perhaps the lessons that we can learn by studying
social networks and non humans, I think there is some
(43:49):
you know, you always have to be careful when you
do this sort of thing. But let me give you
just one example that I think helps in terms of
what we might learn. So there's this great study that
was done on Reese's macaque monkeys and their social networks
on this little island in Puerto Rico. And I won't
(44:12):
get into the details of the social network study per se,
but basically the thing about this study was that they
had been studying these macaques on the island for a
very long time. They knew a lot about their social networks.
Then Hurricane Maria came through and absolutely devastated the island
(44:33):
where these mecacus lived. And obviously it also decimated Puerto
Rico and had all sorts of impacts on our own species,
but it basically destroyed the island that they lived on,
the mecacs lived on, and what that allowed the researchers
to do was study how social networks respond to disasters.
(44:57):
This kind of study was also done in in mice,
how they respond to catastrophic events, social networks respond to
catastrophic events. I think that the more information we get
that on that from non humans, the more we might
be able to understand ways that we might expect social
(45:20):
networks to respond to natural disasters in our own species.
One thing that I think studies and animal behavior allow
us to do is this, If really your primary interest,
and it's perfectly reasonable, would be social networks and non humans,
and you're not all that interested in social networks and
(45:42):
non humans, here's a reason you might want to rethink that.
If you think about this at the species level, we
have a species count of one if we only focus
on humans. But if these social networks are as complex
as they appear to be in non humans, that means
(46:04):
that we have this treasure chest of information about how
social networks work. How does a what does it mean
to be a hub in a social network? How much
does it matter what your friends do versus what your
friends of friends do. It turns out friends of friends
really matter not in non human social networks. How do
(46:26):
these things work? At a most general level, we're if
we only think about humans, our sample sizes one species.
But if we think about it in dolphins and humpback
whales and and manter rays and honey bees and chimpanzees
and so many other species, then all of a sudden,
maybe we can pick up some patterns about social networks
(46:48):
that we wouldn't have picked up otherwise, and so I
think that that's potentially a very powerful implication of studying
this in non humans.
Speaker 2 (46:57):
Yeah, absolutely fascinating. I have one last question that relates
to an earlier book that you wrote was two thousand
and nine, Mister Jefferson and the Giant Moose, Natural History
in Early America. I was not familiar with the history
referenced in the title, as if nothing else, is just
a teaser for listeners who might be interested, Could you
(47:19):
just briefly tell us why Thomas Jefferson was obsessed with
a giant moose?
Speaker 3 (47:25):
Sure? What had happened was the world's leading naturalists in France,
a guy by the name of Count Bufon, had written
this giant encyclopedia of natural history, and one of the
things that he did in an encyclopedia was promote this
idea called the degeneration hypothesis. And what this natural historian
(47:48):
said was that all life in the New World, particularly
in America, was degenerate compared to life other places, that
all the animals in in the United States or even
before that, the colonies were weak, feeble, and diminished compared
to species in other places in the world, and Jefferson
(48:12):
became obsessed in demonstrating to Count Buffon why he was wrong.
In fact, the longest chapter in the book, the only
book that Jefferson ever wrote, The Notes on the State
of Virginia, is all about proving how wrong this degeneracy
hypothesis is. And one of the key pieces of information
(48:33):
that he wanted Buffon to see was our moose, which
was it's massive right. So Jefferson wanted to send Buffon
a giant moose to show him how wrong he was
about this theory of American degeneracy. And so he spent
an extraordinary amount of time and effort getting this moose
(48:54):
and then shipping it over to Buffon. And so that's
where the moose in the title comes from.
Speaker 2 (48:59):
Fascinating. I'm going to I'm gonna have to put this
on my to read list. I was instantly fascinated.
Speaker 3 (49:04):
Oh, thank you, Yeah, I mean, it was a tremendously
fun project.
Speaker 2 (49:07):
Well, Lee, thanks again for coming on the show. The
new book, The Well Connected Animals, Social Networks and the
Wondrous Complexity of Animal Societies is out this week, so
encourage all of our listeners to go check that out.
Speaker 3 (49:20):
Thank you so much for having me. I enjoyed you
very much.
Speaker 2 (49:24):
Thanks once more to Lee Alan Dugatkin for taking time
out of his day to chat with me about the
new book. That new book, again is The Well Connected
Animal Social Networks and the Wondrous Complexity of Animal Societies.
It is out this Thursday, so go grab yourself a copy.
Thanks as always to the excellent JJ Possway for producing
(49:47):
this episode and if you would like to get in
touch with Joe or myself, if you have suggestions for
future episodes of Stuff to Blow Your Mind, If you
have interview suggestions you'd like us to consider, write and
we would love to hear from you. You can email us
at contact at stuff to blow your Mind dot com.
Speaker 1 (50:12):
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