April 21, 2023 • 23 mins
Amazing Wildlife highlights a tiny species from the Southwest hub, one of San Diego Zoo Wildlife Alliance's eight areas of conservation focus. Allison Gregor, a researcher for the organization, speaks with Rick and Marco about a unique rodent that weighs about as much as three pennies: the Pacific pocket mouse! They discuss where this granivore can be found, how its diet determines its biology, the threats facing this species, its surprising life expectancy, and more!
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Episode Transcript
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Speaker 1 (00:04):
Hi, I'm Rick Schwartz and I'm Marco went.
Speaker 2 (00:07):
Welcome to Amazing Wildlife, where we explore unique stories of
wildlife from around the world and uncover fascinating animal facts.
This podcast is a production of iHeartRadio and San Diego
Zoo Wildlife Alliance, in international nonprofit conservation organization which oversees
the San Diego Zoo and Safari Park. Last episode, we
mentioned that we were going to spend some more time
(00:28):
this season exploring the conservation hubs of the San Diego
Zoo Wildlife Alliance and as a reminder, a conservation hub
represents a region of focus for our conservation efforts. These
efforts include working with other zoos and conservation organizations, sharing
knowledge with international communities, and building collaborative partnerships that have
a lasting impact on the survival and well being of
(00:49):
all life on Earth.
Speaker 3 (00:51):
And with our hubs being all over the world, from
the African forest to the savannahs, or the Pacific Islands
to Amazonia, I love that we also have one right
here in our own backyard, the south West Hub.
Speaker 1 (01:05):
Ah.
Speaker 2 (01:06):
Yes to go to the Southwest Hub. Let's see that
hub includes species like the burrowing owl, the desert tortoise
and the mountain yellow legged frog, just to name a few.
Speaker 3 (01:14):
Yeah, you know, it's funny now that you listen like that,
it reminds me of all the different types of ecosystems
in one hub. In the Southwest Hub, we have the
pocket mice that live next to the ocean, the burrowing
owls in the grasslands and desert tortoises in the desert,
and the high altitude mountain yellow leaked frogs.
Speaker 1 (01:35):
Oh.
Speaker 3 (01:35):
My favorite conservation story the California condor.
Speaker 2 (01:39):
You can't forget the condo.
Speaker 3 (01:40):
You can't, especially online. Being the bird guy, gotta highlight
that one. And it's great because they cover all different
ecosystems there.
Speaker 2 (01:47):
Yeah, you bring up a good point. Conservational hubs, like
any region or ecosystem, can have a lot of similar
or different things in them.
Speaker 1 (01:54):
Exactly.
Speaker 3 (01:54):
I mean, for now, I want to stick with the
Southwest Hub just for a little minute, or honestly for
the whole episode.
Speaker 1 (02:01):
Okay, thank you.
Speaker 3 (02:02):
In the last episode, we learned that the environment changes
how some lions live, like being solitary or living alone
instead of being a pride. And we also learned that
the same environment made for the male lines without Manes.
Speaker 2 (02:16):
Yeah, it's true, we did find that out, But what
does that have to do exactly with the Southwest sub Well.
Speaker 3 (02:21):
The species I'm thinking of hasn't necessarily changed due to
the environment it lives in, but the environment it lives
in would change quite a bit without the species.
Speaker 2 (02:32):
Hmmm. All right, so now you have me interested. Which
species are you thinking of?
Speaker 3 (02:36):
Well, you know it would be a little too easy
to tell you, buddy, So I want to see if
you and the listeners can figure out what species we're
going to be talking about if I give you just
a little bit of clues.
Speaker 2 (02:46):
Oh, well, this to be easy. I know a lot
about animals, so I'm always up for a game. Give
me those clues, buddy.
Speaker 1 (02:50):
All right, all right, here we go. Okay, here are
the clues.
Speaker 3 (02:54):
Three pennies graniv ore, toper and soil drology.
Speaker 2 (03:00):
Wait wait, wait, wait wait wait, three pennies torper or
toper in soil hydrology. I know what torpor is, but
I'm not sure about granted or honestly, and how exactly
does three pennies fit into anything in conservation?
Speaker 3 (03:17):
I know, I know it sounds a little wild, but
maybe one more clue will help Guinness Book of World Records.
Speaker 2 (03:25):
Seriously, Marco, that's supposed to help.
Speaker 1 (03:27):
Okay, okaygo.
Speaker 3 (03:29):
I think it will all make sense soon enough when
I tell you I had a really interesting discussion with
one of our behavior researchers.
Speaker 2 (03:37):
Oh okay, well, I'll be listening carefully for those hints,
especially three pennies in Guinness Book a World Record, because
I still don't see how that fits.
Speaker 1 (03:45):
But okay, let's do this. I feel I feel it.
Trust me, it will all come together for you.
Speaker 4 (03:50):
I am Alison Gregor, and I am a researcher with
the San Diego Zoo Wildlife Alliance. I'm very fortunate that
I get to research all sorts of things. My background
is in animal behavior and animal learning, which is common
across many species. I have the pleasure right now of
working with the Pacific pocket mouse team and then also
with the Hawaiian bird team as well, so across several
(04:13):
of our different hubs that.
Speaker 5 (04:14):
We have here.
Speaker 4 (04:15):
But yeah, it means that primarily I get to help
prepare the animals in our care for life in the wild.
Speaker 2 (04:21):
Aha, she said, Pacific pocket mouse and Hawaiian birds and Marco,
because you said you want to talk about the south
West Hub. I'm pretty sure this is going to be
about the Pacific pocket mouse.
Speaker 1 (04:32):
Very clever, very clever. I need to catch that now.
I know you know a thing or.
Speaker 3 (04:37):
Two about them, But Allison, can you tell us, for
anyone listening today that might not be familiar with them,
what is a Pacific pocket mouse?
Speaker 5 (04:45):
That's a great question.
Speaker 4 (04:46):
Most people hear the word mouse and think they know
what they are working with, but actually, the Pacific pocket
mouse is a unique species that's only found in a
small stretch of coast along southern California. They are dry
adapted species and part of the Heteromyad family, and that
means that they have little fur lined cheek pouches that
(05:07):
they use to store and move around seeds. And the
reason why they have those is that because they need
to conserve water. If they were to carry their seeds
in their mouth, they would lose the water from their
saliva when they carry the seeds around.
Speaker 5 (05:21):
So they've evolved.
Speaker 4 (05:22):
They're so dry adaptive they have even involved these little
pouches to help carry their seeds around.
Speaker 2 (05:27):
Huh. Well, that's a cool adaptation. But that makes me
wonder are there any other mice that have an adaptation
like that or is it just a Pacific pocket mouse?
Speaker 4 (05:36):
So any rodents in the Heteromyad family, and that involves
kangaroo rats and a variety of different pocket mice. But
we're lucky here that in our backyard in southern California,
we have the Pacific pocket mouse, and they are found
within four to six kilometers of the coastline. They specialize
in these fine grain sandy soils that are found in
coastal sage scrub habitat and along coastal.
Speaker 5 (05:58):
Dunes, and they here.
Speaker 4 (06:00):
They are unique to our area and are found nowhere else.
Speaker 3 (06:05):
Allison, speaking of unique to our area, I know that
the Pacific pocket mouse is also unique because they are
considered to be one of the smallest mice species here
in North America.
Speaker 1 (06:14):
But how big are they?
Speaker 4 (06:16):
To put it in terms that people might understand it,
they're the weight of about three pennies.
Speaker 2 (06:20):
Ah, there, it is three pennies. That was one of
your hints, Marco.
Speaker 1 (06:25):
Yep, nice cats, Reick.
Speaker 3 (06:26):
And for those of you listening, you can feel just
how little these mice.
Speaker 1 (06:30):
Way.
Speaker 3 (06:30):
All you gotta do is go get three pennies, hold
them in your hand.
Speaker 2 (06:33):
Doesn't weigh much Okay, hold on a second, MARKO, I'm
gonna google this. I like numbers. Let's see how much
just three pennies weigh?
Speaker 1 (06:40):
Oh yeah, okay, what'd you find out?
Speaker 2 (06:42):
Hold on here, this is all right. Let's see US
Treasury website says a penny weighs two point five grams,
So let's see times three. That's about seven point five grams.
Speaker 1 (06:52):
That is so teem, Oh my gosh, so small.
Speaker 3 (06:55):
And oh remind us Allison, where exactly do these little
teeny tiny mice live?
Speaker 4 (07:00):
From the coast up to four to six kilometers depending
on where those soils stop. So they need a very
special type of soil because they dig burrows, and when
they're not out foraging or trying to find mates, they
spend their time down in their burrows, especially over wintertime
when there is much less food availability for them. They
specialize on native seeds from forbes and grasses. But in
(07:23):
the winter times, when you know, in California you don't
have all of the seeds all year round. We have
a seasonal climate here, and so they spend longer periods
underground in their burrows in what we call torpor, which
is like hibernation. Light They don't go down into a
den for months at a time, but they will slow
their metabolic rate and be down for several days, maybe
(07:45):
come up, down for several days, come back up. So
they go through a really interesting physiological change during the
wintertime which helps them be adapted to the landscape that
we have here.
Speaker 2 (07:57):
Aha swarper a state of inactivity that is like short
bouts of many hibernation. That was another one of your clues.
Speaker 1 (08:03):
M Well done, buddy, Alison.
Speaker 3 (08:06):
Earlier when I was giving Rick hints about this episode,
he said he was familiar with what toper is, but
I know some of our listeners may not be as
familiar with it. Can you explain what the mice do
during toper?
Speaker 4 (08:18):
So during that torpor period when they slow their metabolic rate,
they also lower their internal body temperature as well, and
we don't actually know that much about what those patterns
look like in the wild. That's some of the research
that we're doing here with our conservation breeding population to
try and understand what is natural torpor and how is
that impacted by some of human activities. For instance, if
(08:40):
there's sound that might wake them up from their torpor
and then they have to come out of their sleepy
state and go back in rather than being able to
stay asleep. So within our the population that we care
for here, one of our big goals is to try
and understand as much about them as we can so
that we can better support them both in our conservation
efforts and in the wild And so that is one
(09:02):
element of what we're studying.
Speaker 2 (09:04):
Wow, that is really interesting because we often think of
how our use of land as humans takes away space
for wildlife. But the understanding that the sounds and noises
we make can also impact neighboring wild spaces, like waking
an animal out of torpor is something we rarely think of.
Speaker 3 (09:21):
Yeah, right, it's super interesting, isn't it. And with the
Pacific pocket mouse living only in coastal areas and areas
that humans like to build their homes. Also, what does
their current range to look like versus what it looked
like in the past.
Speaker 4 (09:34):
So previously they had had that sweet spot of the
right types of soils and native vegetations across their entire
native range. So that was from about El Segundo Dunes
in Los Angeles County down to the border with Mexico,
and they had that whole area that's also where we
like to build our homes. We like to be able
to have views of the coast, and that's where there's
(09:56):
been a lot of development, so there are very few
patches of habitat left for them. We work with many
partners to try and find the remnants of habitat that
are left and restore actively restore them where possible so
that we can start to put together.
Speaker 5 (10:14):
The remaining population.
Speaker 4 (10:15):
So actually, for twenty years they were undiscovered in the wild,
thought to be completely extinct, and then three tiny remnant
populations were found, so the three little postage stamps along
their whole previous native range, and so once they were rediscovered,
that's when we with the many other partners, started the
planning process of bringing them back and trying to figure
(10:38):
out where can we put populations of pocket mice once
we were able to breed them, and there was a
lot to learn in order to be able to breed
them in human care and figure out how to set
them up for life in the wild. So we're still
along that journey. It's a long journey, but we now
have a fourth population that we've been reintroducing to in
the Laguna Coast Wilderness Park.
Speaker 3 (11:00):
That is most excellent news to go from three small populations,
so now having a fourth population out there is most
definitely a positive trend.
Speaker 2 (11:09):
Yeah right, that is a trend.
Speaker 1 (11:11):
I hope we continue to see Allison.
Speaker 3 (11:13):
I know Rick likes being outdoors as much as I do,
and with both of us living here in southern California,
what are the chances of ever seeing a Pacific pocket
mouse in the wild.
Speaker 4 (11:22):
The one place that's open to the public where there
are a Pacific pocket mice is Dana Point. There's a
small nature reserve on Data Point right along the coast
there that does actually have pocket mice. You're not likely
to see them though, because they're nocturnal, and I believe
the reserve is closed at night, but you will be
in their mist and you will see a habitat that
(11:43):
is impacted by their presence as well. Even if you
don't see them there, they are having an effect.
Speaker 5 (11:48):
The burrows that they create.
Speaker 4 (11:50):
Increase the soil hydrology, so help plants there get water flow.
They also the seeds that they move around, they cache them.
That means they hide them for later, both in their
home burrow and scattered throughout their territory.
Speaker 2 (12:04):
Wait, wait, wait wait, I do want to ask more
about the seed caching you mentioned, but there was another
one of Marco's hints in there, soil hydrology. Alison, you
mentioned of their burrows help with soil hydrology. What exactly is.
Speaker 4 (12:15):
That soil hydrology? So that's the movement of water under
the soil. If you have burrows for the water to
go into, then that brings water further down than it
would be if there weren't any holes on the surface.
Speaker 2 (12:26):
Ah okay, well, I appreciate you clarifying that. I don't
think soil hydrology is really something we think about too often,
but it is interesting how these little mouse's burrows play
such an important role in how water can get into
the soil more effectively and thus allowing the plants to thrive.
Speaker 1 (12:41):
Yeah, exactly.
Speaker 3 (12:42):
I mean it makes me wonder what other little things
that Pacific pock mouse does that are also important for
the ecosystem, and what other things might be challenging for
them in the wild. Hey, Allison, we know as human
populations grow, land development can impact different species in different ways,
like you mentioned looking into noise pollution interfering with toper.
What other challenges are the Pacific pocket mice facing.
Speaker 4 (13:05):
Yeah, that's a very important point. So in addition to
human development, there's been an incredible spread of non native
grasses throughout southern California. I mean, it's happened in many
places in the US and worldwide. But it changes the
habitat to the point where they don't have the bare
ground that they need to signal to each other. They
use their own scent to plot out their territories and
(13:27):
communicate that way, and they don't have the ground.
Speaker 5 (13:29):
That they need for their burrows.
Speaker 4 (13:31):
The non native grasses also hold a lot of fuel
for fires. So we know that fires are a natural
part of the ecosystem here, but because of human impacts,
they are occurring with a lot more frequency and much
higher intensity. So all of that fuel that's held by
the non native grasses burns hotter, which means that it
decimates the ecosystem in a way that would have maybe
(13:53):
been a slow, low fire going through every few decades
now happens at a much faster timeframe and much more tensely,
So that's a major threat to them. Also, close by
to their habitats, they are affected by light pollution, and
this has been shown in many other small mammals, any
nocturnal animal, light pollution is likely to play a disruptive role,
(14:15):
and we don't yet know the effect of sound. That's
one of the things that we are considering. But we
think that they could be vulnerable during their periods of torpor,
because that's when they are trying to sleep.
Speaker 2 (14:26):
Now, Allison, you mentioned that the invasive plants were part
of the problem. These are plants that aren't native to
the ecosystem but start growing there, impacting the Pacific pocket
mouse as food sources, and prior to that you had
mentioned they stash their seeds for later. Do they only
eat seeds or do they eat the other parts of
the plants as well.
Speaker 4 (14:45):
The Pacific pocket mouse is a granovore. They feed primarily
on seeds and that has determined a lot of their
whole biology and their way of being as well.
Speaker 5 (14:55):
So they collect seeds.
Speaker 4 (14:57):
To be able to have them at times when there
aren't se eats available. They hide seeds in the landscape
and in this way, by being a gran of ore,
they help spread the seeds around as well, which can
have a benefit to the plants too.
Speaker 1 (15:12):
Hey, Rick, did you catch that one? Yep?
Speaker 2 (15:14):
Granivre? Another one of your hints from earlier, just going
to check the list here. Let's see three pennies torpor
soil hydrology or understanding how water gets into the soil,
and now granivre an animal that eats seeds for its
primary food source.
Speaker 4 (15:29):
They eat nothing else and they don't even take standing water.
Speaker 2 (15:33):
So where do they get their water from?
Speaker 5 (15:36):
They get their water from their seeds.
Speaker 1 (15:39):
Gay in descente how interesting.
Speaker 5 (15:41):
So that's how dry adapted they are.
Speaker 4 (15:44):
It is likely that they might on occasion take a
little bit of vegetation, or they might have an insect
here and there, but they are primarily granivores, which means
that they are specialized and adapted to eat seeds, both
physiologically that's why they have furlined seed pouches so they
can fill them with seeds and move them around, but
(16:04):
also likely cognitively as well, so they learn where and
how to hide their seeds so that they have them
to be able to survive the winter. So they are
absolutely tied to seeds.
Speaker 3 (16:16):
I love that they hide their seeds for later, like
some bird.
Speaker 1 (16:19):
Species that I love.
Speaker 2 (16:20):
It's right, Marco, and I want to ask you, Allison,
where do they hide their seeds?
Speaker 4 (16:25):
They create little burrows and they hide their caches of seeds,
and by doing so that helps spread seeds native seeds.
They don't necessarily find them all, so to speak. And
so they are helping the ecosystem continue. And they might
seem like a very small player, but they're an important
part of that puzzle.
Speaker 2 (16:41):
Okay, I hate to admit it, but I can relate
to forgetting about food that I have stashed. I mean,
in my case, food that I've stashed in the back
of the fridge.
Speaker 1 (16:48):
But yeah, totally.
Speaker 3 (16:50):
But the food stash you forget about turns moldy and stinky.
Right at least when the Pacific pocket most or gets
its food stash, the forgotten sash of seeds just grows
into more plants and helps the ecosystem.
Speaker 2 (17:02):
Yeah, you're not wrong there. My leftovers are not seeds
helping the ecosystem.
Speaker 1 (17:06):
Yeah, I bet.
Speaker 3 (17:06):
I mean, I know, my leftover at the metallists are
definitely not helping plants to grow.
Speaker 1 (17:10):
But okay, okay, we're getting a little side tracked here.
Speaker 3 (17:12):
Obviously, the Pacific pocket mouse is an important part of
the ecosystem. They live in Allison and the whole team
working on the Pacific pocket mouse conservation are doing great
work to build the population back up. Is this a
species that lives for a long time.
Speaker 4 (17:27):
So in the wild, the Pacific pocket mouse do not
live very long at all, two to three years maximum
and many don't live longer than that. They are the
type of species that is a live, fast, die young
type species.
Speaker 5 (17:39):
It's true.
Speaker 4 (17:39):
You can have some species that take a long time
to mature and they take a long time to reproduce,
and that's a long lifestyle. Their life history is much
more compact. A pocket mouse that is born in the
early part of the season can go on to reproduce
that same year, so there can be grand offspring of
one of the mice that we release, oh wow.
Speaker 5 (18:01):
Within the same year if we time it right.
Speaker 4 (18:03):
And so because of that, and because they are the
smallest enamel in their ecosystem, there are a lot of
things that eat them, and so there are a lot
of threats out there, natural ones, but means that they
do not have long life spans. What we've been able
to do in human care is expand that life span
due to the wonderful veterinary team we have here and
(18:24):
those are also our welfare teams. That are really thinking
about how we give them the best life possible.
Speaker 5 (18:30):
And we now have.
Speaker 4 (18:32):
The world's oldest mouse and human care, not just world's
oldest pocket mouse, but world's oldest mouse ever in human care.
And his name is Patrick Stewart and he is over
nine and a half years old and still going. So
we were very lucky to have some recognition from the
Guinness Book because it's something that our teams have been
(18:54):
working on for a long time to be able to
sit back and realize what they have accomplished with that,
and he really is the flag bear for all of
the wonderful care and the species that we have here.
Speaker 2 (19:03):
Hold up, wait, did you just say Guinness Book. That
was one of your hints, MARKO. Guin us Book a world.
Speaker 1 (19:09):
Record, Yeah, yeah, totally was just a few months ago.
Speaker 3 (19:12):
Pacific pocket mouse Patrick Stewart was awarded for his longevity
at nine years, two hundred and nine days in February,
making him officially recognized by the Guinness Book of World
Records as the oldest living mouse under human care.
Speaker 1 (19:28):
Snaps for Patrick.
Speaker 2 (19:29):
Stewart and now finally all of your hents, even threepennies
and Guinness Book of World records. If it all makes sense.
Speaker 3 (19:38):
I'm really stoked you forget it all out, friend, and
right as we were wrapping up this episode, but before that,
I want to ask Allison if there's anything we didn't
cover that she'd like to add.
Speaker 5 (19:49):
That's a good question.
Speaker 4 (19:50):
I think it's very easy to look at.
Speaker 5 (19:54):
A mouse and think why do I care?
Speaker 4 (19:56):
But really, the more you learn about pocket mice, there
are so many unique features to them that make them
really incredible. And that's the case with many of these
less charismatic species that may not be the poster child
for a lot of our efforts, but.
Speaker 5 (20:11):
They really are incredible in their own way.
Speaker 4 (20:13):
I'd say a lot of our ongoing work really tries
to both better understand them as a species but reveal
more of these things that make them truly what they are.
Speaker 3 (20:22):
What is it that you like most about the Pacific
pocket mouse.
Speaker 4 (20:26):
I think they are just an incredible example of a
very well adapted species, and every species is adapted to
its specific environment.
Speaker 5 (20:36):
But the more we learn about how tied they are.
Speaker 4 (20:38):
To this ecosystem, it's just been incredible and a journey
for me really to see those connections and really see
them as part of the ecosystem and how they weave
into that big picture.
Speaker 5 (20:48):
Yeah, that's been great, Machisie.
Speaker 3 (20:51):
Let's get asked us, Alison. You've given us great insight
to these mighty little.
Speaker 2 (20:55):
Nice Yes, Alison, thank you so much, amazing insight. Indeed,
we are so fortunate to have been able to learn
so much in Marco. Although your hints didn't help me
going into this episode, I appreciate discovering it along the
way what they were for.
Speaker 3 (21:09):
Thank you friend, Thank you friend, Thank you for playing
back the way.
Speaker 1 (21:11):
I'm glad that you enjoyed it.
Speaker 3 (21:13):
And honestly, I learned a few things myself, like I
had no idea that they don't drink water and just
get the hydration they need from the seeds that they eat.
Speaker 2 (21:21):
Yeah, you know. And speaking of that hydration, the whole
part about how their tunnels and burrows help with soil
hydration so the plants can thrive really highlighted how important
these little mice are to their ecosystem exactly.
Speaker 3 (21:34):
We sometimes only see how wildlife lives off of the
plants and their habits at but the more we learn,
the more we see how each species is an important part.
Speaker 1 (21:42):
Of the whole ecosystem. In this case of the Pacific.
Speaker 6 (21:45):
Pocket mouse, not only do their burrows help water reach
deeper into the soil, but their seed sashes that go
uneaten help disperse the seeds and create new growth for
native plants.
Speaker 2 (21:56):
Truly a little mouse that matters.
Speaker 1 (21:59):
Love it, they really really are.
Speaker 3 (22:01):
I know I learned a few things, and I hope
everyone listening today did too.
Speaker 2 (22:05):
I know I will forever remember the only weigh as
much as three pennies.
Speaker 1 (22:09):
I know mixed me.
Speaker 3 (22:09):
Want to go find three pennies. Maybe I'm gonna check
my couch and find out the feel of it, right,
how little that actually weighs?
Speaker 2 (22:16):
Exactly? Me too, I was thinking of the same, like,
where can I find three pennies? Who has coins anymore?
I'm gonna find them. I'm gonna find three pennies. I'
gonna carry him around some little pocket mouths. It's so cool,
all right? Everyone, be sure to subscribe and tune into
our next episode, in which we uncover some curious facts
about one of South America's well known reptiles.
Speaker 1 (22:37):
Marco Lent and I'm Rick Schwartz.
Speaker 2 (22:39):
Thanks for listening for more information about the San Diego
Zoo and San Diego Zoo Safari Park. Go to SDZWA
dot org. Amazing Wildlife is a production of iHeartRadio. Our
supervising producer is Nikia Swinton and our sound designer and
editor is Sierra Spreen. For more shows from iHeartRadio, check
out the iHeartRadio app, Apple Podcasts, or wherever you listen
(23:02):
to your favorite shows.
Hi, I'm Rick Schwartz and I'm Marco went.
Speaker 2 (00:07):
Welcome to Amazing Wildlife, where we explore unique stories of
wildlife from around the world and uncover fascinating animal facts.
This podcast is a production of iHeartRadio and San Diego
Zoo Wildlife Alliance, in international nonprofit conservation organization which oversees
the San Diego Zoo and Safari Park. Last episode, we
mentioned that we were going to spend some more time
(00:28):
this season exploring the conservation hubs of the San Diego
Zoo Wildlife Alliance and as a reminder, a conservation hub
represents a region of focus for our conservation efforts. These
efforts include working with other zoos and conservation organizations, sharing
knowledge with international communities, and building collaborative partnerships that have
a lasting impact on the survival and well being of
(00:49):
all life on Earth.
Speaker 3 (00:51):
And with our hubs being all over the world, from
the African forest to the savannahs, or the Pacific Islands
to Amazonia, I love that we also have one right
here in our own backyard, the south West Hub.
Speaker 1 (01:05):
Ah.
Speaker 2 (01:06):
Yes to go to the Southwest Hub. Let's see that
hub includes species like the burrowing owl, the desert tortoise
and the mountain yellow legged frog, just to name a few.
Speaker 3 (01:14):
Yeah, you know, it's funny now that you listen like that,
it reminds me of all the different types of ecosystems
in one hub. In the Southwest Hub, we have the
pocket mice that live next to the ocean, the burrowing
owls in the grasslands and desert tortoises in the desert,
and the high altitude mountain yellow leaked frogs.
Speaker 1 (01:35):
Oh.
Speaker 3 (01:35):
My favorite conservation story the California condor.
Speaker 2 (01:39):
You can't forget the condo.
Speaker 3 (01:40):
You can't, especially online. Being the bird guy, gotta highlight
that one. And it's great because they cover all different
ecosystems there.
Speaker 2 (01:47):
Yeah, you bring up a good point. Conservational hubs, like
any region or ecosystem, can have a lot of similar
or different things in them.
Speaker 1 (01:54):
Exactly.
Speaker 3 (01:54):
I mean, for now, I want to stick with the
Southwest Hub just for a little minute, or honestly for
the whole episode.
Speaker 1 (02:01):
Okay, thank you.
Speaker 3 (02:02):
In the last episode, we learned that the environment changes
how some lions live, like being solitary or living alone
instead of being a pride. And we also learned that
the same environment made for the male lines without Manes.
Speaker 2 (02:16):
Yeah, it's true, we did find that out, But what
does that have to do exactly with the Southwest sub Well.
Speaker 3 (02:21):
The species I'm thinking of hasn't necessarily changed due to
the environment it lives in, but the environment it lives
in would change quite a bit without the species.
Speaker 2 (02:32):
Hmmm. All right, so now you have me interested. Which
species are you thinking of?
Speaker 3 (02:36):
Well, you know it would be a little too easy
to tell you, buddy, So I want to see if
you and the listeners can figure out what species we're
going to be talking about if I give you just
a little bit of clues.
Speaker 2 (02:46):
Oh, well, this to be easy. I know a lot
about animals, so I'm always up for a game. Give
me those clues, buddy.
Speaker 1 (02:50):
All right, all right, here we go. Okay, here are
the clues.
Speaker 3 (02:54):
Three pennies graniv ore, toper and soil drology.
Speaker 2 (03:00):
Wait wait, wait, wait wait wait, three pennies torper or
toper in soil hydrology. I know what torpor is, but
I'm not sure about granted or honestly, and how exactly
does three pennies fit into anything in conservation?
Speaker 3 (03:17):
I know, I know it sounds a little wild, but
maybe one more clue will help Guinness Book of World Records.
Speaker 2 (03:25):
Seriously, Marco, that's supposed to help.
Speaker 1 (03:27):
Okay, okaygo.
Speaker 3 (03:29):
I think it will all make sense soon enough when
I tell you I had a really interesting discussion with
one of our behavior researchers.
Speaker 2 (03:37):
Oh okay, well, I'll be listening carefully for those hints,
especially three pennies in Guinness Book a World Record, because
I still don't see how that fits.
Speaker 1 (03:45):
But okay, let's do this. I feel I feel it.
Trust me, it will all come together for you.
Speaker 4 (03:50):
I am Alison Gregor, and I am a researcher with
the San Diego Zoo Wildlife Alliance. I'm very fortunate that
I get to research all sorts of things. My background
is in animal behavior and animal learning, which is common
across many species. I have the pleasure right now of
working with the Pacific pocket mouse team and then also
with the Hawaiian bird team as well, so across several
(04:13):
of our different hubs that.
Speaker 5 (04:14):
We have here.
Speaker 4 (04:15):
But yeah, it means that primarily I get to help
prepare the animals in our care for life in the wild.
Speaker 2 (04:21):
Aha, she said, Pacific pocket mouse and Hawaiian birds and Marco,
because you said you want to talk about the south
West Hub. I'm pretty sure this is going to be
about the Pacific pocket mouse.
Speaker 1 (04:32):
Very clever, very clever. I need to catch that now.
I know you know a thing or.
Speaker 3 (04:37):
Two about them, But Allison, can you tell us, for
anyone listening today that might not be familiar with them,
what is a Pacific pocket mouse?
Speaker 5 (04:45):
That's a great question.
Speaker 4 (04:46):
Most people hear the word mouse and think they know
what they are working with, but actually, the Pacific pocket
mouse is a unique species that's only found in a
small stretch of coast along southern California. They are dry
adapted species and part of the Heteromyad family, and that
means that they have little fur lined cheek pouches that
(05:07):
they use to store and move around seeds. And the
reason why they have those is that because they need
to conserve water. If they were to carry their seeds
in their mouth, they would lose the water from their
saliva when they carry the seeds around.
Speaker 5 (05:21):
So they've evolved.
Speaker 4 (05:22):
They're so dry adaptive they have even involved these little
pouches to help carry their seeds around.
Speaker 2 (05:27):
Huh. Well, that's a cool adaptation. But that makes me
wonder are there any other mice that have an adaptation
like that or is it just a Pacific pocket mouse?
Speaker 4 (05:36):
So any rodents in the Heteromyad family, and that involves
kangaroo rats and a variety of different pocket mice. But
we're lucky here that in our backyard in southern California,
we have the Pacific pocket mouse, and they are found
within four to six kilometers of the coastline. They specialize
in these fine grain sandy soils that are found in
coastal sage scrub habitat and along coastal.
Speaker 5 (05:58):
Dunes, and they here.
Speaker 4 (06:00):
They are unique to our area and are found nowhere else.
Speaker 3 (06:05):
Allison, speaking of unique to our area, I know that
the Pacific pocket mouse is also unique because they are
considered to be one of the smallest mice species here
in North America.
Speaker 1 (06:14):
But how big are they?
Speaker 4 (06:16):
To put it in terms that people might understand it,
they're the weight of about three pennies.
Speaker 2 (06:20):
Ah, there, it is three pennies. That was one of
your hints, Marco.
Speaker 1 (06:25):
Yep, nice cats, Reick.
Speaker 3 (06:26):
And for those of you listening, you can feel just
how little these mice.
Speaker 1 (06:30):
Way.
Speaker 3 (06:30):
All you gotta do is go get three pennies, hold
them in your hand.
Speaker 2 (06:33):
Doesn't weigh much Okay, hold on a second, MARKO, I'm
gonna google this. I like numbers. Let's see how much
just three pennies weigh?
Speaker 1 (06:40):
Oh yeah, okay, what'd you find out?
Speaker 2 (06:42):
Hold on here, this is all right. Let's see US
Treasury website says a penny weighs two point five grams,
So let's see times three. That's about seven point five grams.
Speaker 1 (06:52):
That is so teem, Oh my gosh, so small.
Speaker 3 (06:55):
And oh remind us Allison, where exactly do these little
teeny tiny mice live?
Speaker 4 (07:00):
From the coast up to four to six kilometers depending
on where those soils stop. So they need a very
special type of soil because they dig burrows, and when
they're not out foraging or trying to find mates, they
spend their time down in their burrows, especially over wintertime
when there is much less food availability for them. They
specialize on native seeds from forbes and grasses. But in
(07:23):
the winter times, when you know, in California you don't
have all of the seeds all year round. We have
a seasonal climate here, and so they spend longer periods
underground in their burrows in what we call torpor, which
is like hibernation. Light They don't go down into a
den for months at a time, but they will slow
their metabolic rate and be down for several days, maybe
(07:45):
come up, down for several days, come back up. So
they go through a really interesting physiological change during the
wintertime which helps them be adapted to the landscape that
we have here.
Speaker 2 (07:57):
Aha swarper a state of inactivity that is like short
bouts of many hibernation. That was another one of your clues.
Speaker 1 (08:03):
M Well done, buddy, Alison.
Speaker 3 (08:06):
Earlier when I was giving Rick hints about this episode,
he said he was familiar with what toper is, but
I know some of our listeners may not be as
familiar with it. Can you explain what the mice do
during toper?
Speaker 4 (08:18):
So during that torpor period when they slow their metabolic rate,
they also lower their internal body temperature as well, and
we don't actually know that much about what those patterns
look like in the wild. That's some of the research
that we're doing here with our conservation breeding population to
try and understand what is natural torpor and how is
that impacted by some of human activities. For instance, if
(08:40):
there's sound that might wake them up from their torpor
and then they have to come out of their sleepy
state and go back in rather than being able to
stay asleep. So within our the population that we care
for here, one of our big goals is to try
and understand as much about them as we can so
that we can better support them both in our conservation
efforts and in the wild And so that is one
(09:02):
element of what we're studying.
Speaker 2 (09:04):
Wow, that is really interesting because we often think of
how our use of land as humans takes away space
for wildlife. But the understanding that the sounds and noises
we make can also impact neighboring wild spaces, like waking
an animal out of torpor is something we rarely think of.
Speaker 3 (09:21):
Yeah, right, it's super interesting, isn't it. And with the
Pacific pocket mouse living only in coastal areas and areas
that humans like to build their homes. Also, what does
their current range to look like versus what it looked
like in the past.
Speaker 4 (09:34):
So previously they had had that sweet spot of the
right types of soils and native vegetations across their entire
native range. So that was from about El Segundo Dunes
in Los Angeles County down to the border with Mexico,
and they had that whole area that's also where we
like to build our homes. We like to be able
to have views of the coast, and that's where there's
(09:56):
been a lot of development, so there are very few
patches of habitat left for them. We work with many
partners to try and find the remnants of habitat that
are left and restore actively restore them where possible so
that we can start to put together.
Speaker 5 (10:14):
The remaining population.
Speaker 4 (10:15):
So actually, for twenty years they were undiscovered in the wild,
thought to be completely extinct, and then three tiny remnant
populations were found, so the three little postage stamps along
their whole previous native range, and so once they were rediscovered,
that's when we with the many other partners, started the
planning process of bringing them back and trying to figure
(10:38):
out where can we put populations of pocket mice once
we were able to breed them, and there was a
lot to learn in order to be able to breed
them in human care and figure out how to set
them up for life in the wild. So we're still
along that journey. It's a long journey, but we now
have a fourth population that we've been reintroducing to in
the Laguna Coast Wilderness Park.
Speaker 3 (11:00):
That is most excellent news to go from three small populations,
so now having a fourth population out there is most
definitely a positive trend.
Speaker 2 (11:09):
Yeah right, that is a trend.
Speaker 1 (11:11):
I hope we continue to see Allison.
Speaker 3 (11:13):
I know Rick likes being outdoors as much as I do,
and with both of us living here in southern California,
what are the chances of ever seeing a Pacific pocket
mouse in the wild.
Speaker 4 (11:22):
The one place that's open to the public where there
are a Pacific pocket mice is Dana Point. There's a
small nature reserve on Data Point right along the coast
there that does actually have pocket mice. You're not likely
to see them though, because they're nocturnal, and I believe
the reserve is closed at night, but you will be
in their mist and you will see a habitat that
(11:43):
is impacted by their presence as well. Even if you
don't see them there, they are having an effect.
Speaker 5 (11:48):
The burrows that they create.
Speaker 4 (11:50):
Increase the soil hydrology, so help plants there get water flow.
They also the seeds that they move around, they cache them.
That means they hide them for later, both in their
home burrow and scattered throughout their territory.
Speaker 2 (12:04):
Wait, wait, wait wait, I do want to ask more
about the seed caching you mentioned, but there was another
one of Marco's hints in there, soil hydrology. Alison, you
mentioned of their burrows help with soil hydrology. What exactly is.
Speaker 4 (12:15):
That soil hydrology? So that's the movement of water under
the soil. If you have burrows for the water to
go into, then that brings water further down than it
would be if there weren't any holes on the surface.
Speaker 2 (12:26):
Ah okay, well, I appreciate you clarifying that. I don't
think soil hydrology is really something we think about too often,
but it is interesting how these little mouse's burrows play
such an important role in how water can get into
the soil more effectively and thus allowing the plants to thrive.
Speaker 1 (12:41):
Yeah, exactly.
Speaker 3 (12:42):
I mean it makes me wonder what other little things
that Pacific pock mouse does that are also important for
the ecosystem, and what other things might be challenging for
them in the wild. Hey, Allison, we know as human
populations grow, land development can impact different species in different ways,
like you mentioned looking into noise pollution interfering with toper.
What other challenges are the Pacific pocket mice facing.
Speaker 4 (13:05):
Yeah, that's a very important point. So in addition to
human development, there's been an incredible spread of non native
grasses throughout southern California. I mean, it's happened in many
places in the US and worldwide. But it changes the
habitat to the point where they don't have the bare
ground that they need to signal to each other. They
use their own scent to plot out their territories and
(13:27):
communicate that way, and they don't have the ground.
Speaker 5 (13:29):
That they need for their burrows.
Speaker 4 (13:31):
The non native grasses also hold a lot of fuel
for fires. So we know that fires are a natural
part of the ecosystem here, but because of human impacts,
they are occurring with a lot more frequency and much
higher intensity. So all of that fuel that's held by
the non native grasses burns hotter, which means that it
decimates the ecosystem in a way that would have maybe
(13:53):
been a slow, low fire going through every few decades
now happens at a much faster timeframe and much more tensely,
So that's a major threat to them. Also, close by
to their habitats, they are affected by light pollution, and
this has been shown in many other small mammals, any
nocturnal animal, light pollution is likely to play a disruptive role,
(14:15):
and we don't yet know the effect of sound. That's
one of the things that we are considering. But we
think that they could be vulnerable during their periods of torpor,
because that's when they are trying to sleep.
Speaker 2 (14:26):
Now, Allison, you mentioned that the invasive plants were part
of the problem. These are plants that aren't native to
the ecosystem but start growing there, impacting the Pacific pocket
mouse as food sources, and prior to that you had
mentioned they stash their seeds for later. Do they only
eat seeds or do they eat the other parts of
the plants as well.
Speaker 4 (14:45):
The Pacific pocket mouse is a granovore. They feed primarily
on seeds and that has determined a lot of their
whole biology and their way of being as well.
Speaker 5 (14:55):
So they collect seeds.
Speaker 4 (14:57):
To be able to have them at times when there
aren't se eats available. They hide seeds in the landscape
and in this way, by being a gran of ore,
they help spread the seeds around as well, which can
have a benefit to the plants too.
Speaker 1 (15:12):
Hey, Rick, did you catch that one? Yep?
Speaker 2 (15:14):
Granivre? Another one of your hints from earlier, just going
to check the list here. Let's see three pennies torpor
soil hydrology or understanding how water gets into the soil,
and now granivre an animal that eats seeds for its
primary food source.
Speaker 4 (15:29):
They eat nothing else and they don't even take standing water.
Speaker 2 (15:33):
So where do they get their water from?
Speaker 5 (15:36):
They get their water from their seeds.
Speaker 1 (15:39):
Gay in descente how interesting.
Speaker 5 (15:41):
So that's how dry adapted they are.
Speaker 4 (15:44):
It is likely that they might on occasion take a
little bit of vegetation, or they might have an insect
here and there, but they are primarily granivores, which means
that they are specialized and adapted to eat seeds, both
physiologically that's why they have furlined seed pouches so they
can fill them with seeds and move them around, but
(16:04):
also likely cognitively as well, so they learn where and
how to hide their seeds so that they have them
to be able to survive the winter. So they are
absolutely tied to seeds.
Speaker 3 (16:16):
I love that they hide their seeds for later, like
some bird.
Speaker 1 (16:19):
Species that I love.
Speaker 2 (16:20):
It's right, Marco, and I want to ask you, Allison,
where do they hide their seeds?
Speaker 4 (16:25):
They create little burrows and they hide their caches of seeds,
and by doing so that helps spread seeds native seeds.
They don't necessarily find them all, so to speak. And
so they are helping the ecosystem continue. And they might
seem like a very small player, but they're an important
part of that puzzle.
Speaker 2 (16:41):
Okay, I hate to admit it, but I can relate
to forgetting about food that I have stashed. I mean,
in my case, food that I've stashed in the back
of the fridge.
Speaker 1 (16:48):
But yeah, totally.
Speaker 3 (16:50):
But the food stash you forget about turns moldy and stinky.
Right at least when the Pacific pocket most or gets
its food stash, the forgotten sash of seeds just grows
into more plants and helps the ecosystem.
Speaker 2 (17:02):
Yeah, you're not wrong there. My leftovers are not seeds
helping the ecosystem.
Speaker 1 (17:06):
Yeah, I bet.
Speaker 3 (17:06):
I mean, I know, my leftover at the metallists are
definitely not helping plants to grow.
Speaker 1 (17:10):
But okay, okay, we're getting a little side tracked here.
Speaker 3 (17:12):
Obviously, the Pacific pocket mouse is an important part of
the ecosystem. They live in Allison and the whole team
working on the Pacific pocket mouse conservation are doing great
work to build the population back up. Is this a
species that lives for a long time.
Speaker 4 (17:27):
So in the wild, the Pacific pocket mouse do not
live very long at all, two to three years maximum
and many don't live longer than that. They are the
type of species that is a live, fast, die young
type species.
Speaker 5 (17:39):
It's true.
Speaker 4 (17:39):
You can have some species that take a long time
to mature and they take a long time to reproduce,
and that's a long lifestyle. Their life history is much
more compact. A pocket mouse that is born in the
early part of the season can go on to reproduce
that same year, so there can be grand offspring of
one of the mice that we release, oh wow.
Speaker 5 (18:01):
Within the same year if we time it right.
Speaker 4 (18:03):
And so because of that, and because they are the
smallest enamel in their ecosystem, there are a lot of
things that eat them, and so there are a lot
of threats out there, natural ones, but means that they
do not have long life spans. What we've been able
to do in human care is expand that life span
due to the wonderful veterinary team we have here and
(18:24):
those are also our welfare teams. That are really thinking
about how we give them the best life possible.
Speaker 5 (18:30):
And we now have.
Speaker 4 (18:32):
The world's oldest mouse and human care, not just world's
oldest pocket mouse, but world's oldest mouse ever in human care.
And his name is Patrick Stewart and he is over
nine and a half years old and still going. So
we were very lucky to have some recognition from the
Guinness Book because it's something that our teams have been
(18:54):
working on for a long time to be able to
sit back and realize what they have accomplished with that,
and he really is the flag bear for all of
the wonderful care and the species that we have here.
Speaker 2 (19:03):
Hold up, wait, did you just say Guinness Book. That
was one of your hints, MARKO. Guin us Book a world.
Speaker 1 (19:09):
Record, Yeah, yeah, totally was just a few months ago.
Speaker 3 (19:12):
Pacific pocket mouse Patrick Stewart was awarded for his longevity
at nine years, two hundred and nine days in February,
making him officially recognized by the Guinness Book of World
Records as the oldest living mouse under human care.
Speaker 1 (19:28):
Snaps for Patrick.
Speaker 2 (19:29):
Stewart and now finally all of your hents, even threepennies
and Guinness Book of World records. If it all makes sense.
Speaker 3 (19:38):
I'm really stoked you forget it all out, friend, and
right as we were wrapping up this episode, but before that,
I want to ask Allison if there's anything we didn't
cover that she'd like to add.
Speaker 5 (19:49):
That's a good question.
Speaker 4 (19:50):
I think it's very easy to look at.
Speaker 5 (19:54):
A mouse and think why do I care?
Speaker 4 (19:56):
But really, the more you learn about pocket mice, there
are so many unique features to them that make them
really incredible. And that's the case with many of these
less charismatic species that may not be the poster child
for a lot of our efforts, but.
Speaker 5 (20:11):
They really are incredible in their own way.
Speaker 4 (20:13):
I'd say a lot of our ongoing work really tries
to both better understand them as a species but reveal
more of these things that make them truly what they are.
Speaker 3 (20:22):
What is it that you like most about the Pacific
pocket mouse.
Speaker 4 (20:26):
I think they are just an incredible example of a
very well adapted species, and every species is adapted to
its specific environment.
Speaker 5 (20:36):
But the more we learn about how tied they are.
Speaker 4 (20:38):
To this ecosystem, it's just been incredible and a journey
for me really to see those connections and really see
them as part of the ecosystem and how they weave
into that big picture.
Speaker 5 (20:48):
Yeah, that's been great, Machisie.
Speaker 3 (20:51):
Let's get asked us, Alison. You've given us great insight
to these mighty little.
Speaker 2 (20:55):
Nice Yes, Alison, thank you so much, amazing insight. Indeed,
we are so fortunate to have been able to learn
so much in Marco. Although your hints didn't help me
going into this episode, I appreciate discovering it along the
way what they were for.
Speaker 3 (21:09):
Thank you friend, Thank you friend, Thank you for playing
back the way.
Speaker 1 (21:11):
I'm glad that you enjoyed it.
Speaker 3 (21:13):
And honestly, I learned a few things myself, like I
had no idea that they don't drink water and just
get the hydration they need from the seeds that they eat.
Speaker 2 (21:21):
Yeah, you know. And speaking of that hydration, the whole
part about how their tunnels and burrows help with soil
hydration so the plants can thrive really highlighted how important
these little mice are to their ecosystem exactly.
Speaker 3 (21:34):
We sometimes only see how wildlife lives off of the
plants and their habits at but the more we learn,
the more we see how each species is an important part.
Speaker 1 (21:42):
Of the whole ecosystem. In this case of the Pacific.
Speaker 6 (21:45):
Pocket mouse, not only do their burrows help water reach
deeper into the soil, but their seed sashes that go
uneaten help disperse the seeds and create new growth for
native plants.
Speaker 2 (21:56):
Truly a little mouse that matters.
Speaker 1 (21:59):
Love it, they really really are.
Speaker 3 (22:01):
I know I learned a few things, and I hope
everyone listening today did too.
Speaker 2 (22:05):
I know I will forever remember the only weigh as
much as three pennies.
Speaker 1 (22:09):
I know mixed me.
Speaker 3 (22:09):
Want to go find three pennies. Maybe I'm gonna check
my couch and find out the feel of it, right,
how little that actually weighs?
Speaker 2 (22:16):
Exactly? Me too, I was thinking of the same, like,
where can I find three pennies? Who has coins anymore?
I'm gonna find them. I'm gonna find three pennies. I'
gonna carry him around some little pocket mouths. It's so cool,
all right? Everyone, be sure to subscribe and tune into
our next episode, in which we uncover some curious facts
about one of South America's well known reptiles.
Speaker 1 (22:37):
Marco Lent and I'm Rick Schwartz.
Speaker 2 (22:39):
Thanks for listening for more information about the San Diego
Zoo and San Diego Zoo Safari Park. Go to SDZWA
dot org. Amazing Wildlife is a production of iHeartRadio. Our
supervising producer is Nikia Swinton and our sound designer and
editor is Sierra Spreen. For more shows from iHeartRadio, check
out the iHeartRadio app, Apple Podcasts, or wherever you listen
(23:02):
to your favorite shows.
Hosts And Creators
Rick Schwartz
Marco Wendt
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