The Surprising Species That Everything Else Depends On | IN OUR NATURE (2)
and lots of eyes. The wildebeests migrate, but their predators
don't. So that helps them get eaten less and moving gives wildebeests access to more food
than if they stayed in one place. Migration is why this population is so big, but even
a place as vast as the Serengeti, it's not infinite. Okay. So when there's plenty to
eat, you know, when the rainy season is happening, well, the bone marrow of those wildebeests
is nice and fatty, but in the dry season, when there isn't as much to eat, bone marrow
gets kind of gross. And when scientists looked at the bones of most dead wildebeests, it
was pretty nasty inside. So they think that most wildebeests starved to death. Okay.
But some of them do get eaten by lions, hyenas predators.
Yes. Some lions are definitely having lunch, but predators are not what keeps this population
from growing. It's how much food there is to eat during the dry season. They aren't
regulated from the top down. They're regulated from the bottom up, scientists call this kind
of population limit the carrying capacity. It's basically how much life and ecosystem.
So The grass is regulating the wildebeests and
the wildebeests are regulating everything else.
Yeah. Yeah. And if there's too many wildebeests one year, then more of them die, and if the
numbers get too low, next year, there's extra food to go around the numbers come back up.
It's like a boom and bust economy. Yeah, exactly. And what is so amazing to me
is that this ecosystem is regulating itself. We're going to be telling a lot more stories
from this place. I don't think you can really appreciate the Serengeti without understanding
why it exists. And if the species at the middle of everything disappears, if their migration
is disrupted by climate change or other human development, would this whole place collapse
with them? I mean, Serengeti has rebounded once before, but without the wildebeests,
could it do it again? You know, there are so many aspects of this
story that remind me of the history of bison in north America, bison, bison, are like the
national mammal. Right? Right. Yeah. So bison are these Pleistocene giants that have been
in North America for over a hundred thousand years. But as settlers arrived between the
1700s in the 1900s, the US Army sanctioned these huge eradication programs targeting
the bison, but also in an effort to eradicate the people here, millions of these bison were
slaughtered many for just their coats or their skulls. And the population went from an estimated
30 to 60 million individuals to just a few hundred in the course of a couple of centuries.
That must've had some impact on the ecosystem. Yeah. It's hard to find a comparison and cows
graze too, but bison graze differently. They love grasses and they pass on most of the
other shrubs. So that increases biodiversity by providing food and shelter
for all the other animals. They create these huge wallows in these pits, compact soil.
So they're, microhabitats for resilient plants, bison even impact other soil and plant processes
through the ingestion and expulsion of their waste. Love a good poop story. Yeah. Good old species
feces note for you. Anyway, I can totally see where 30 million bison pooping would leave
a distinct ecological mark, a skid mark. Right. So anyway, there's a lot of different
groups that are trying to reintroduce bison to their historic ranges. But here's the bigger
question that I have, are these restoration efforts more about healing, a landscape and
ecosystem or about healing people? I thought we were talking about the biology and like,
you know, animals. Right. I mean, but we don't live in a vacuum,
Joe. It's about both. Okay. You're right. You're right. So prairie's used to be the
biggest ecosystems in north America. They covered 170 million acres, 20
times bigger than the Serengeti. That is wow. Right. But by now prairie's have been so heavily
cultivated and developed. They're one of the most endangered ecosystems in the world, but
there happens to be one not far from where I am, outside of Chicago.
So we are standing in this green field, which is the site of a prairie restoration project
between the 1930s and 70s. This area looked nothing like this. We went to Midewin National
Tall Grass Prairie. Today, it's the only federally protected tall grass prairie in the United
States. But before it was a prairie, it was something else entirely. We are going to see
a war ammunition storage bunker. What is this doing out here? Well, before
Midewin was taken over by the US forest service, it was an army property. And it was used during
the middle part of the 1900s to manufacture and store military ordinance. They produced
them onsite and then they stored them in buildings like this.
Whoa. Wow. It is just like a giant cement tube. Yeah.
Sounds like a shotgun in there. That's so cool. And there used to be like 400 of these
bunkers. They stored over a billion pounds of TNT. It was a huge operation.
So what happened, once they took the bombs and the explosives out of the bunkers? What
did they do? So that is when the real work began. They
transferred the land from the Army to the US Forest Service in the 90s, but it was pretty
polluted and overgrown. So they had to start pulling the invasive species and reintroducing
native plants, but they were still missing one key element. We're talking about bison,
right? I mean, the bison are the real environmental engineers here. They are the prairie's Keystone
species, Ding, ding, ding, ding, ding, ding, ding.
Many of the plants and grasses, the birds and the insects that once called this area
home can't return until the bison do too. But it's all part of a big experiment at Midewin,
trying to understand these plant animal interactions and the model organism was not
easy to find. So we got word earlier today that the herd
of bison is somewhere in the area. Emily, I was told there would be bison in
this episode. We just got a call that someone has spotted
them over this Ridge. There are bison out there.
Yep. You can see them there. They're kind of just below the horizon there with those
trees. Oh yeah. I can see them. They're pretty far
out there. They are far out. Can you ask them to come a little closer? Uh, I could ask him,
uh, they, they do what they want though. That's fair.
Okay. So you take this incredibly polluted place and you get rid of the invasive species,
bring back the bison and you get prairie. I mean, that's part of it, but you have to
remember that bison didn't live here in isolation. They lived here alongside people for tens
of thousands of years. People that relied on the bison for every part of their livelihood,
for food and shelter, ceremonial objects, weapons. The removal of bison was a direct
assault on the people. The people who played a major role in the ecosystem to today, there's
a huge effort on part of indigenous nations to reintroduce bison to tribal land. And one
of those groups is the Intertribal Buffalo Council. The Intertribal Buffalo Council actually
was originated in 1992, a group of people out of native American fish and wildlife services
decided why are we not doing something to return Buffalo to our tribes?
That's Arnell Abold. She's the executive director of the ITBC. And talking to her, you really
get a sense of how passionately she feels about this project.
We look at all of our tribes as individuals, but together we're force, you know, to be
reckoned with. There's so much heartbeat to it. And there's so much soul to it, you know,
and there's just that real connection to the Buffalo. But you know, our core has always
been returning the Buffalo to tribal lands. And in some ways they're helping with the
literal health of their kids. Diabetes is such a big disease on all of our
reservations and Buffalo meat, bison meat is one of the most healthy alternatives you
can eat. And that kind of puts it back, you know, back into our hands a little bit. If
we can do that What have been some of your proudest achievements. When we bring
new herds onto tribal land, if you can heal the Buffalo, the land and the people and make
that circular connection, imagine the changes that can happen. Maybe they can't happen today,
but we're seeing positive changes across Indian country, no matter what, maybe it's just adding
three Buffalo onto their lands. That's a change that's positive that gives that community
something to find a little hope in. It was actually super touching. Not only it
restoring the bison is helping the ecosystem. It's actually helping so many other things
as well. Yeah. And you know, it was cool. We were invited
to go see the bison on the Pine Ridge reservation in South Dakota. But unlike our visit to Midewin,
this, this was really different. The Oglala Sioux that manage the herd in pine Ridge
hold a Buffalo dance ceremony once a year, where they sing, they do dances and they honor
their spiritual connection to the bison. But when they heard that we were coming, they
offered to hold a special Buffalo ceremony just for us as a way of welcoming our visit
to the herd. And it was one of the coolest, most touching things that I've ever been in.
It's really meaningful because these are first relatives come out. They're nervous. Look
at the ground. They're going to come in afraid. They don't know what kind of energy that we
carry. Including us in the ceremony. It was a way
of demonstrating that we're bringing good vibes. And then Robert Goodman, the biologist
for Oglala Sioux Parks and Recreation took us out to see the herd. There they are.
Yeah. I think I even see like a little baby bison out there. How many bison did you say
you had here? Today? Probably around a thousand.
So when you imagine sort of the historic numbers of like, you know, estimates of 30 million
Buffalo on the landscape, do you have some kind of idea for like the impact those numbers
would have had? I don't know. It's hard to wrap your mind
around herds that are majored in square miles. Instead of numbers, Buffalo are kind of known
as a Keystone species. They really do impact a lot of other animals like the prairie dogs.
They graze down the grass and that takes away cover for the predators of the prairie dog.
So they like it. And then the prairie dogs actually, where they've cropped it off, they've
produced different types of plants that the Buffalo liked to graze, so it kind of works
back and forth. Antelope are known to rely on Buffalo too. In the winter time when it's
snow is really deep, they can't push the snow out in forage as well as the Buffalo. So they'll
follow right in Buffalo tracks and grays behind them. And you know, just about all of the
species that you think of when you think of prairie species are related to the Buffalo
or rely on the Buffalo. Robert told me that the Buffalo will distribute
seeds of native plants that get caught in their shaggy coats. And even the hoof prints
that they leave behind holds water for prairie birds. So it's easy to see that with the removal
of bison, everything gets out of whack. I mean, that's amazing to think about, but these
are, these are relationships, ecological relationships that have existed for hundreds of thousands
of years. I mean, these things have evolved together. They've really, um, become to rely
