Jane: This is But Why: a Podcast for Curious Kids from Vermont.
Public I'm Jane Lindholm. On this show, we gather all kinds
of questions from all kinds of kids from all kinds of places,
and then we gather a few of the questions and present them to
someone who might at least have some of the answers. Today,
we've gathered questions about one specific type of animal, and
we're going all the way from Vermont to San Diego to get
those answers for you. The animals we're going to learn
more about today are lizards. Here in Vermont, where I live,
we only have one type of lizard. In fact, there's only one type
of Lizard that lives in all of New England, the region Vermont
is part of. It's called the Five lined Skink, and it's endangered
here in Vermont. It's only found in two towns here, and I've
never seen one. I love lizards. That probably comes as no
surprise to those of you who have listened to a lot of
episodes. I think I say I love the animals we're about to talk
about in every animal episode we make. But since we don't have
many lizards in my neck of the woods, I took advantage of a
recent work trip to California and made a beeline for a place
that has lots of lizards, like thousands of them. But here's
the rub, the lizards in the place I visited are not alive. I
went to a museum with a research facility where they study
reptiles and amphibians and they preserve specimens of each
species so they can study them even after those individual
animals are dead. Let's go there right now.
Adam: This is the vault. So this is the deepest part of the whole
museum. We're about three floors underground right now, and the
room is sort of divided into two halves. So the half off to the
left here, this is all of the wet, preserved invertebrate
collections, and then everything on the right hand side of the
room facing me, these are all the reptile and amphibian
specimens that I manage as the Collection Manager of
Herpetology here at the Natural History Museum.
Jane: So to give kids a little bit more of a sense, when you
say the specimens you manage, we are talking not about live
animals.
Adam: We are not so we're talking about all animals that
were once alive but which are now dead and preserved. So these
are not replicas. These are all real animals that were once
alive. And you can sort of think of a collection like this as a
library, where, instead of books in my library, we have preserved
specimens. And so just like a book, you can open up every
specimen in every jar in this room, and you can read it like a
book. You can look at what that specimen was eating before it
died. You can look at what kinds of parasites it might have
inside its body or on its body, like ticks or parasitic worms.
And we can track change across space and change across time. So
there's so many different things that we can learn from dead
animals that help us to better protect and understand how to
conserve them in the wild. And so it's a really powerful
resource. It's, I tell people, it's sort of like drowning in
chocolate for me to be in this room.
Jane: It's a little bit weird to say drowning in chocolate when
you're also talking about like dissecting animals and seeing
what they ate and what ticks they have on their body.
Okay, yeah, I still think it's weird to associate chocolate
with preserved reptile specimens in jars of alcohol. But who am I
to yuck, someone else's yum? And this, someone else we're talking
to here is Adam Clause. His official title is collections
manager of herpetology at the San Diego Natural History
Museum. But sometimes it's hard to understand what someone does
just from their title. So I asked Adam to explain what his
job actually is.
Adam: So I get to basically be a kid as an adult. So when I was
about the age of many of you who are listening right now I was
catching lizards in my backyard in Southern California, and I
was marking them with different dots of colored paint so I could
tell which one was which and how many are in my in my yard. And
so I kind of get to do that all the way to today as an adult, I
get to go out outdoors, outside in wild places, and sometimes in
suburban areas. And I get to catch lizards. I get to catch
snakes. I get to learn about them, and then I get to share
that information with everybody through scientific publications.
So writing down what I see, interpreting what I see, and
then sharing those results, what I'm learning with the world.
Jane: In addition to going out and looking for wild animals,
Adam also keeps track of all those specimens we were looking
at when I visited the museum. You heard him mention that we
were deep in the bottom of the museum. It's a big, climate
controlled room that has almost 80,000 specimens or preserved
animals. The specimens are stored in jars that are filled
with liquid, usually a kind of alcohol, that preserves the
animals so they don't decay or deteriorate. They're mostly in
jars with white lids that kept reminding me of pickle jars,
some small pickle jars and some other really, really big pickle
jars, except instead of pickles, the jars were full of
rattlesnakes and turtles and other things that were
definitely not pickles. Most of the animals in the collection
come from the local area, Southern California and the Baja
Peninsula of Mexico. They have over 1,700 different species of
reptiles and amphibians in the collection.
Adam: And by reptiles and amphibians, just to be clear, we
mean things like crocodilians, snakes, lizards, turtles. We
have one tuatara and then for amphibians, those are the three
main groups, are salamanders and newts, frogs and toads. And then
the really weird group that almost nobody's ever heard of.
They look like giant earthworms, but they're not earthworms,
they're amphibians, and these are called the caecilians, and
they are strictly tropical, so we don't have any in our region
or any in the US, but we have a few specimens in the collection.
Jane: Before we got to the questions, I was there to ask
Adam about, all of your lizard questions, I asked him if he
could show us something in the collection.
Adam: How about we open up a tank? Yeah. And so in the room,
as we mentioned, most of the specimens are kept in jars, but
glass jars usually don't get manufactured much larger than
one gallon in size. So if we have specimens like really big
iguanas or really big snakes that just don't fit inside a
gallon jar, we have to have another way of storing them. And
our solution is these steel tanks that we fill with fluid
and we store the animals in there. So I'm going to open up
one of these tanks right now.
Jane: This is tank 10, and it says on top of it, iguanids,
yes.
Adam: So these are like iguanas. And then we have a Gila monster.
And then, weirdly enough, we have a few Galapagos, tortoise
feet, just the feet, not the shell, just the feet.
Jane: Wow. The smell is really distinct when you open it up,
yep. So it smells, if you're an adult, kind of like sherry,
Adam: Sure. So it's actually the exact same chemical that you
know adults drink in their alcoholic beverages. It's
ethanol or ethyl alcohol. So it's not toxic, per se, but the
way it preserves the animals is it just makes a solution, a
mixture of ethanol and water that bacteria and fungi cannot
live in. So if a bacterial cell were to get dropped into this
fluid, all the water would get sucked out of it and it would
die.
Jane: So if I coughed into it, it wouldn't damage anything.
Adam: It wouldn't damage anything at all. Yeah.
Jane: So what do you do with these iguanas that are preserved
in here? They're very it's very cool looking. They're sort of,
some of them are preserved where they're sort of curved around
their own tails.
Adam: So we can do all manner of things. People can study the
genetics. We can look at their DNA. We can look at how their
coloration varies between males and females. We can look at how
coloration might vary in certain parts of their distribution
versus others. We can cut them open if we wanted, and see what
they were eating. We can cut them open and see what kinds of
parasitic worms might be living in their bodies, and sometimes
those can be brand new species that nobody's ever described or
given a name to. We can do so many things. It's almost an
unlimited number of questions. And what's really fascinating
about collections like these is that they're super long term. So
these, a lot of these specimens are decades old. Some of the
specimens in our collection are more than 150 years old. And so
what that means is these specimens could be potentially
used for things in the future that we don't even have any
idea, that we could even ask these questions now.
Jane: I'm glad you showed me the iguanas, because what we're here
to talk to you specifically about today are lizards. And
iguanas are a kind of lizard. So can we share some of the
questions from kids that we got about lizards?
Adam: Yeah, let's do that.
Jane: Maybe you can explain, since we were talking about
reptiles and amphibians, what lizards are?
Adam: Sure! So lizards are vertebrates, so they have
backbones, just like we do vertebral columns, and they're
also characterized by usually having very scaly skin, and so
that helps them to avoid drying out, so the scales help keep the
moisture inside their bodies. And so a lot of reptiles like
lizards, they can live in really, really hot, dry places
like deserts, because of how the skin keeps all their water in
their bodies.
Jane: So lizards are reptiles, not amphibians. That's correct.
Some lizards look a lot like salamanders, but salamanders are
amphibians, so and salamanders have scales, right? Or do the
skin not have scales?
Adam: That gets back to what defines a lizard, so those
scales are the big differentiator. So salamanders
are going to have smooth, sort of wet skin, or at least moist
skin, somewhat similar to ours, versus a lizard is always going
to have scales on its skin. That's the big separating, or
the big that's the big differentiator between those two
groups.
Quentin: Hi. My name is Quentin, and I am six and a half years
old, and I live in Alaska, Anchorage, and my question is,
why do lizards have scales?
Rowan: Hi, my name is Rowan. I am six years old. I live in
Houston, Texas, and my question is, why do lizards have scales?
Finn: My name's Finn and I'm five years old, and I live in
Raleigh, North Carolina. I want to know why do lizards have
scales.
My name is Artis. I live in Torquay, Australia, and my and
I'm six, almost seven. And my question is, why do lizards have
scales?
Jane: Can you go a little deeper into the scales of lizards?
Adam: Yeah, so it really helps them to live in a lot of
different habitats that would otherwise be very difficult for
them to live in. The deserts, as I mentioned, are one of the
prime examples. Deserts are very hard places for animals to live
in, because they're so dry and because they're so hot, and so
when you have a protective layer of armoring over your skin, like
scales, which is what lizards do have, that opens up a whole
realm of possibilities for places on the earth that they
can live in and maybe avoid competition from other species
that don't necessarily have those protections on their skin,
and so that gives them the ability to live in places with
less competition.
Jane: You also mentioned the scales help them keep moisture
in. How do scales do that?
Adam: So you can think of scales as sort of they're very similar
to your fingernails, so they're hard, they're impermeable to
water, and so water doesn't travel through the scale the way
it does through your skin. And so that's basically how it
works. It's like a barrier. That's a good way to think of
it.
Evelyn: I'm from Quebec, Canada, and my name is Evelyn. I'm six
years old, and why are lizard cold blooded? And why are people
not cold blooded too?
Adam: This is a really, really great question, and I'm glad
that you asked this one so it's actually not true. Technically,
that lizards are cold blooded. The way it works is the big
differentiator between lizards and say, humans, is that we
maintain our body temperature, and hence our blood temperature
at a really consistent temperature, and we do that
which part of the reason we do that is to make sure that all of
our organs are at the sort of the same optimal conditions for
operating.
Jane: So if I go sledding in Vermont and it's one degree
Fahrenheit, my body temperature is still staying around 98 and
then if I come here to San Diego and I hike up the hills at 80
degree weather, my body temperature is still right
around 98 degrees.
Adam: That's right. But if you were a lizard and you went from
the Arctic to the deserts, your blood temperature and your body
temperature would mimic whatever the surrounding temperatures
are. So sometimes that means that lizards blood temperatures
are quite cold, and other times it can mean that their blood
temperature is quite a bit warmer than ours. So on average,
yes, their blood tends to be a little bit colder than ours, but
it can also be quite a bit warmer than ours. So it's just
their blood is not it's not at a fixed temperature the way humans
and mammals are their blood temperature varies according to
the environment.
Jane: I thought that's what cold blooded was. So why do you say
they're not technically cold blooded? But it's this is like
science that goes against what I was taught as a kid.
Adam: So it depends on what you mean by cold, right? If cold
means colder than human blood, then it's not true, because
there are many lizards, in many contexts that can have blood
temperatures well over 100 degrees. And so that's it's hard
to argue that that's cold blood in that particular context. It's
just that their blood temperature it varies. It's not
consistent.
Jane: I see so it's almost like it's just that a bad name for
the way we regulate our temperature, or the way they
regulate their temperature.
Adam: That's right, it's kind of an over-simplification of what
they do.
Jane: Got it. Phew. I was gonna have to review my whole, you
know, world view here. If that was not the case, we have
another question from Grayson.
Greyson: I'm Greyson. I'm five years old. I live in Pittsburgh,
Pennsylvania. My question is, do chameleons sleep or hibernate?
Because in the Wildcat how I saw them awake at night.
Jane: So Grayson wonders, do chameleons sleep or hibernate?
How do lizards think about those two things, which are quite
different.
Adam: They are quite different. So hibernation is typically
something that a lizard is going to do if it lives in a really
seasonal environment, where, if it gets really cold during the
winter and much warmer during the summers, during the winter,
the lizard might cease or stop most of its activity. Its blood
temperature will get quite cold, and it won't really be running
its metabolism anymore. So. Won't need to feed. It won't
need to eat, and they'll just sort of let go into a long
sleep, roughly analogous to what like a bear does during the
winter, right? But if you're a lizard that lives in a more warm
or a more stable environment, you can be active all year
round, and you never really have to hibernate. Sleeping is a
different matter. So sleeping is something that pretty much every
vertebrate needs to do at some point on a daily cycle. And
lizards are no different. So all lizards have to sleep, similar
to the way humans have to sleep.
Jane: So specific then to chameleons. Yes, they sleep, and
are chameleons hibernators.
Adam: Most chameleons live in pretty warm climate. I think
most chameleons, it's safe to say, do not hibernate, but there
might be some that do. I'm not sure. The other thing to keep in
mind is that some lizard species are fully nocturnal, so they're
sleeping during the day and being out and about, foraging
and looking for food and looking for mates at night. So that's
the other important thing to remember when we're talking
about lizards sleeping, is they don't all sleep at night. Some
of them sleep during the day.
Jane: I looked this up Grayson, and it appears that chameleons
are generally not known to be nocturnal, but I've seen the
Wild Kratts episode you're talking about, and there is that
chameleon in the dark. That episode, though, also features
another animal, a type of lemur known as an aye aye, and that
animal is nocturnal, so maybe the Wild Kratts took some
artistic liberties to make the episode work.
Julian: I'm I'm Julian, I'm five. I'm from Houston, Texas,
and my question is, why do lizards can stick their tongue
out to their eye, and we can't.
Agatha: My name is Agatha. I'm a six year old, and I live in
California. My question is, why do lizards and snakes and other
reptiles stick their tongues out very often?
Jane: Tell us about lizard tongues?
Adam: Yeah, so there's a couple things going on there. So first
of all, only a few lizard species can actually lick their
eyes. Most lizards, in fact, cannot, any more than most
humans cannot lick their eyes, right? But a lot of Geckos can.
And part of the reason why they do this, I'm generalizing a
little bit here, but part of the reason is that a lot of geckos
have a thin, transparent scale that covers their eyes, and so
they don't have eyelids, and so to clean their eyes, to clean
the scale that covers their eyes, they don't have eyelids to
do it. So they've co opted their tongue to do the work for them.
So it's basically they're cleaning their eyes. Is the
reason why they lick them.
Is that eye scale different from a nictitating membrane that some
animals have that can come down and protect their eye, but is
different from an eyelid.
It's very different in the sense that the scale is not related to
an eyelid structure at all. It's it's a scale just like any other
scale on the animal's body, except it's transparent.
Jane: So they can see through it.
Adam: They can see through it. Yeah. And that's also the case
for snakes. Every snake has the same, the same type of eye. They
have a transparent scale covering the eye, and this is
why some people don't like snakes when they see them,
because they think they have this rigid, unblinking stare,
right? It's because they literally can't blink. They
don't have eyelids.
Jane: So when a snake is about to shed its skin, sometimes its
eye looks cloudy. And is that because it's it's sort of
separating all of its scales from its body?
Adam: Exactly so, because the scale over the eye is just like
any other scale, it gets shed when the snake sheds its skin,
and during that process, a very thin layer of moisture gets
produced between the new skin and the old skin. And when
you're looking at the eye, you're basically looking at that
cloudy moisture separating the two scales, and it's only once
the old scale gets left off that the transparency comes back.
Jane: But lizards don't shed, or do they?
Adam: They absolutely shed. All lizards shed their skin, just
like snakes do.
Jane: So you might see a lizard with a foggy eye too.
Adam: If it's one of the lizards that doesn't have eyelids,
that's a possibility.
Jane: Okay, so back to their eyes, so and their tongues is
where we were really supposed to be going. So some of them can
lick their eyes, but most can't. So what do they use their
tongues for?
Adam: So they use it for similar things that we use it for, for
sort of manipulating food and moving food around within their
mouths. Other species or groups like chameleons, for instance,
have highly adapted tongues where they're shooting the
tongue way outside the mouth, and the tongues are very sticky,
and they glom on to a prey item, like a cricket that they want to
eat, and then the tongue pulls that cricket back into the
mouth. That's sort of an extreme case. And then another purpose
for the tongue is that a lot of lizards use it to sense smells
in their environment. So they're using their nose similar to the
way we use our nose, but the tongue is sort of the secondary
sensory mechanism where they're detecting smells by sticking
their tongue out and tasting the air or tasting the ground, as
the case may be. So multi- purpose tongues for a lot of
animals.
Jane: Do lizards have forked tongues?
Adam: Some do and some do not. So it depends on the group of
lizard. So you can imagine a Komodo dragon, for instance,
they have very deeply forked tongues. But your Bearded
Dragon, which you might have as a pet at home, they have just a
tiny, tiny little fork at the tip of the tongue, but it
basically looks like your tongue, unless you're looking
really closely.
Jane: Do you know how many kinds of lizards there are?
Adam: There are over 7,000 described species of lizards,
and there are more being described every day. And so
that's something that I do as part of my work as a scientist.
So I've participated in the description of three new lizard
species in my life, and we're working on a couple more right
Jane: That's so exciting. What does it feel like to find a new
now.
lizard that hasn't been as you as you say, described before,
that, you know, human. That doesn't mean that that humans
didn't know about it before, but it hasn't been put into the
scientific record. What is it like to do that?
Adam: It feels really cool. It's a real thrill. So one of my
childhood dreams was to do this when I was the age of many of
you listening right now, I wanted to describe new species
when I was a boy, and so when I turned 30, I was finally able to
do that.
Jane: What did you name them? Did you get the naming rights?
Adam: Absolutely. So we were part of a team, so it wasn't
just me. And so the team agreed for this particular lizard. We
wanted to call it the Sierra Morena arboreal alligator
lizard. So it's kind of a mouthful, but they're very cool
lizards that live up in the forest canopy, and that's part
of the reason why this one went undiscovered for so long, is
because they're really out of sight of where most humans are
when they're walking in the forest.
Jane: What about its scientific name?
Adam: Scientific name is abronia marinica.
Grace: My name is Grace, and I'm five years old, and I live in
Tempe, Arizona, and my question is, how do lizards stick to
things?
Nicholas: Hi, my name is Nicholas. I live in Halifax. I'm
six years old, and my question is, how do lizards attach to
walls?
Adam: So it's a little bit complicated, and I will just say
that it's not the same type of sticking that is like when you
think about stickiness, like if it's a post it note or tape,
it's not that way on the lizard's feet, they don't have
technically sticky toes. What they do have is toes that have
these really big patches on the underside of the toes that have
all these teeny, teeny, tiny hairs. And those hairs increase
the surface area of those toe pads, they're often called. And
so when they touch a surface, they have all this surface area
from the toe that's contacting whatever it is that they're
touching. And there's these very strange forces that only apply
in really small distances, and they're called Van der Waals
forces. It's a very complicated name, and basically these Van
der Waals forces are what allow geckos to stick, quote, unquote,
stick their feet to the walls.
Jane: So they don't have suction cups.
Adam: They do not have suction cups. A lot of, some frogs do,
and they frogs use a suction cup action. But with lizards, it's a
very different style of stickiness.
Jane: And not all lizards can stick to walls.
Adam: Goodness, no. There's actually only a small subset of
lizards that can stick to walls. Most lizards cannot climb walls
like that.
Jane: Coming up. You may have heard that lizards can lose
their tails and then grow new ones. Is that true? Stay with
us.
This is But Why. I'm Jane Lindholm, and today we're
learning all about lizards with Adam Clause, who manages the
reptile and amphibian collection at the San Diego Natural History
Museum. We did the interview down in the basement of the
museum, where 80,000 specimens are preserved in jars full of
liquid for scientists to be able to study and learn from them.
Adam has been answering all kinds of lizard questions you've
sent us. So let's get to some more.
Lizards are famous for being one of the kinds of animals that
sometimes loses their tail and can grow it back. And we have a
lot of kids who are wondering how they do that.
Rahan: Hi, I'm Rahan. I live in Jakarta, Indonesia. I'm six
years old, and my question is, how do lizards grow their tails
back?
Luis: Hi, my name is Luis. I am 11, and I live in Fort Collins,
Colorado. And my question is, how do lizards tails grow back?
Lenka: Hello. My name is Lenka. I'm seven years old. I live in
the Czech Republic, and my question is, when lizard's tail
falls off why does a new one grow?
Thomas: My name is Thomas. I'm four years old. I live in
Pennsylvania, Harmony and my question is, why do lizards lose
their tails?
Adam: So not all lizards can, can break their tails, or at
least not intentionally, but many lizards can, and they do it
as a defense mechanism, as a way to escape a predator. So you can
imagine, if you know a dog or a cat were to attack a lizard.
Bird and just grab it by its tail, the lizard would want to
sort of separate itself from the tail, which is somewhat
disposable, right? It can live without its tail, and then it
can use that mechanism to sort of escape while the dog or the
cat or whatever it is that attacked, it is focused on the
tail. And so most lizards that can lose their tails in that
way, on each on each bone of the tail, each vertebra, there's
actually a crack, and that crack serves as the point where that
tail will break if you squeeze it or grab it really tightly. So
they're adapted to lose their tails. It doesn't really hurt
them. They bleed very little when this happens. And in fact,
the muscles at the tip of the tail where the break happens,
they all clench down and prevent a lot of blood loss. So it's not
great for the lizard, but they've adapted to where it's
not this, this, this potentially lethal event in their lives. And
then they regrow their tails because a lot of lizards use
their tails for things like balance when they run or balance
when they're climbing, they'll often use it as sort of a device
or a way for males to signal their health to females. And so
having a full tail is really important to some lizards for
reproduction. And so the way they regrow it is they don't
regrow the bone. They can never regrow the bone, but what they
can grow is like a little cartilaginous rod that grows out
and has a little bit of muscle and soft tissue around the edges
and scales on the outside for the skin, but the regrown tail
never ever looks exactly like the original. So you can always
tell when a lizard has broken off its tail if you look really
closely, because the scales aren't the right size, the
scales aren't the right color, and there's no bone inside. So
if you X ray a lizard, you can know for sure if a tail is
regenerated, because the bones will just stop and then it's
just cartilage from then on.
Jane: Cartilaginous is one of my favorite words. It's such a good
Adam: Yeah, that's right. That's exactly right.
word. And if you if you want to think about what is cartilage
versus what is bone, you can feel in your nose, the part that
wiggles, but is a little bit hard that's cartilage. Or you
have cartilage in the top of your ears, and you can kind of
bend it, but it still gives your your body part, that structure.
Talia: Hi. Mine is Talia. I'm six years old. I live in Marina,
California. My question is, why do lizards have different teeth
than humans?
Adam: So it's mostly related to their diet. So if you have an
herbivorous lizard, it's going to have teeth that are going to
be slightly different, for shearing off and then chewing up
leaves or vegetation, versus a lizard that might be feeding on
insects and it needs to sort of capture its prey and hold on to
it with much larger, sharper teeth. So it really all depends
on what you're eating. Humans sort of have a mixture of teeth,
right? We have a couple sharp teeth in our mouth, and then
towards the back we have our molars, which are better for
grinding food. And so we're well adapted to sort of eat both meat
and plants. But most lizards don't do that, sort of that
breadth of what they can eat. They sort of specialize on one
type of prey or another, and so their teeth just reflect that
that diet.
Jane: Are some lizards carnivores?
Adam: Most lizards are. There's very few lizards that don't eat
any meat, per se.
Jane: Yeah. All right, so here's one that we always have to
answer for every animal, because it's just, I don't know, I think
it fascinates us.
Maeve: Hi, my name is Maeve.
Adult: How old are you?
Maeve: Six years old.
Adult: Where do you live?
Maeve: Massachusetts.
My question is do lizards poop or pee, or do they have a
combined?
Iris: My name is Iris, and four years old, and I live in Rupert,
and my question is, why do lizards poop?
Adam: All lizards poop and pee. I can say that unequivocally, no
exceptions. The weird thing about their pee is that most
lizards do not pee a fluid the way we do their pee is actually
a solid, sort of chalky white or whitish yellow substance that's
called uric acid. And so they do that to help reduce the amount
of water that they lose from their bodies. And so this is
particularly common in lizards that live in hot, dry places,
because pee creates a lot of water, and water is really
valuable if you're in the desert, so you don't want to
lose a lot of your body's water by peeing. And so what lizards
do instead is they concentrate their urine down to this chalky
white substance, and that's how they get rid of their nitrogen
waste, instead of using water to dilute the nitrogen waste and
expel it from the body. Poop is just kind of poop. It's the
waste materials, or the materials that an animal can't
digest in its in its stomach or in its intestine, and so it's
just pooped out as waste.
What color is tha?
Typically brown, but it can depend. Yeah, it can depend.
Jane: When I got here to San Diego from Vermont, and I knew I
was going to come and talk to you, I was on a mission to see a
lizard as quickly as possible, and I landed at night, so I
didn't have a chance at night, because we talked about how
they're not going to necessarily be out as much in the in the
night, when it's cooler, and then in the morning, I went for
a walk, and I saw a Western fence lizard. Tell me about
those.
Adam: So they're really great lizards. I think you may have
heard me talk about earlier, the lizards that I was catching in
my backyard as a kid growing up. That was the lizard. So they're
often sometimes called Blue bellies, because on the
underside of their bellies, the males, in particular, the boys,
they will have these bright blue patches, and they use those to
signal both to other male lizards, hey, this is my
territory, stay away, as well as to signal to female lizards.
Hey, I might make a good mate. I'm really healthy and vigorous.
And so what they do is this really distinctive display that
we call the push up display. So they will sort of push their
belly out so that it's sort of flattened. And then they will
literally do push ups from their front legs to show off their
bellies to any other lizards that happen to be standing by.
Jane: Well, that lizard was either not a male or not
impressed by me. It did not do any push ups.
Adam: Sometimes they'll even do push ups at people, if they sort
of feel threatened and they're like, Get away from me. This is
my territory. They'll push up at you. They're very, very spunky.
Jane: What are some other cool lizards that are native to this
area in the southwest, Southern California and Mexico? The Baja
Peninsula.
Adam: There's so many. It's Southern California and the Baja
Peninsula are some of the best places to be a lizard biologist,
because there's so many different types. One of the most
famous one is a lizard that some of you may have heard of. It's
called the chuckwalla. So this is the second largest lizard
species in California. They're about the size of a bearded
dragon, and similar to a bearded dragon, they're sort of plump,
right? They have a big belly. They're strict herbivores, so
they're only eating plant material, and they like to live
in rocks, specifically like rock crevices. And so when
chuckwalla's feel threatened, they will enter a rock crevice,
and they'll wedge themselves as deeply as they can, and then
they'll gulp air into their lungs, and they'll blow up their
body like a balloon with air in their lungs. And by wedging
themselves in with that air pressure, it's impossible to
pull them out unless you do what the first peoples or the Native
Americans would have done, because these are such large
lizards, they have really meaty legs, so there's a lot of
dietary value in a lizard like that. So they would take
chuckwalla sticks, basically a sharpened stick, and they would
pop the chuck wallahs like balloons, and then pull them out
from the rocks. Yeah. So that's one.
Jane: Good technique.
Adam: It is a good technique. It worked. It worked. And you can
find them in the deserts of Southern California, as well as
in parts of Arizona, Southern Utah. So they're pretty
widespread. Another really popular lizards, or type of
lizard, is the banded gecko. So these are much smaller lizards,
unlike the chuckwalla, which are active during the day, the
banded geckos are mostly active at night. And if you go and
drive slowly on desert roads in the spring and summertime, you
can find these geckos crossing the roads, walking along. And
they're also pretty special, because if they feel threatened,
they can squeak, they can actually vocalize. Very few
lizards can do this, but banded geckos are one of them.
Jane: Geckos are kind of famous for their vocalizations, right?
Adam: Yeah, a lot of geckos can squeak. Yeah.
Geckos are very cool, but so are a lot of other kinds of lizards.
We're going to end today's episode here because it's
already getting really long, but we're going to come back with a
bonus episode next week where we can get really specific about
some extra cool kinds of lizards, and your questions
about them, like, how do chameleons change color? What's
a Komodo dragon, and how did it get that name? What's the
smallest lizard in the world? And have you ever heard of a
tuatara, looks just like a lizard, but is it? Adam Clause,
who manages the reptile and amphibian collection at the San
Diego Natural History Museum, will be back to answer even more
of your questions in that bonus episode. As you know, you can
ask us a question on just about anything. Have your adult help
you record you asking the question. They can use one of
the free voice apps that comes on a smartphone. And if you
aren't able to talk, or you don't want to share your voice,
you can have your adult type out your question, then send it to
questions@butwhykids.org. We really wish we could answer all
of your brilliant and thought provoking queries, but we do
listen to them, and sometimes, like in this episode, we come
back to them months or even years after you've sent them.
It's hard not to get them answered right away. I know, but
did you know we have more than 20,000 questions we are trying
as hard as we can to get to as many as we can. But Why is made
at Vermont Public and distributed by PRX. Our
producers are Sarah Baik, Melody Bodette and me,Jane Lindholm,
Joey Palumbo is our video producer, and Luke Reynolds
wrote and performed our theme music. If you like our show,
please give us a review or a like on whatever platform you
use to listen to us. We'll be back in one week with an all new
episode. Until then, stay curious.