Serengeti Rules (2018) - full transcript

So, Bob, we're all ready now.
I'm not. OK.

OK? Yes.

So, where do we start, Bob?

How do you tell people
about what it is you do

and what it is you discovered?

My... my voice
won't be any good, but...

I tell them I've always been excited
about natural history.

That I learned to be an observer
as a child.

And...

...just by being out there,
being vigilant...

...you know something intimately,
one recognises change.



Why is the world we know so well
changing?

One of the greatest gifts
science has to offer

is a way to make sense of our world.

The big names, the names
that are etched into the columns

of museums and buildings.

Newton, Darwin,

they saw the world
in such a different way

than what had come before.

As I researched this story,

I discovered a handful of people
you've never heard of

who went out into the world and saw
things that nobody had seen,

thought things that
nobody had thought.

And what they discovered
will change the way you see nature.

At a time when stories about the
environment are all gloom and doom,



this is an unique story of hope.

And one we'd be very wise to hear.

When I was a child,

I was severely myopic
from who knows what age.

I didn't know that you could see
leaves on a tree from the ground.

I remember my parents and I
were standing at this lake

in New Brunswick

and there was a moose
on the other side of the lake

in full view of my parents,
and I couldn't see it.

And they said, "What?! You can't
see that? What's wrong with you?"

But something happened before I got
glasses, and that was

that I was let loose
with a mask and snorkel.

Hey, Mary, too close.

But, Mum, there's fish in here.

For the first time,
I saw things clearly

because of the refraction
of the water.

There was a lot of beauty,
and it was all sharply-focused.

You can imagine
how beautiful it would be

when you see detail that
you'd never known you could see.

What were pondweeds above the water

were forests of stems
under the water.

And in this little forest,
there would be sunfish.

Then, occasionally,
a big larger predator

like a pickerel or a perch
or a bass goes by.

It was a flashbulb moment,
as they say,

where I just had to be underwater,

looking at life that way
for the rest of my life.

At the time, there were dozens and
dozens of really strong ecologists

working in coral reef biology,

but nobody was doing
underwater ecology in rivers.

And that's a who-cooks-for-you owl.

Who cooks for you?

I actually think it's incredibly
important that we understand

where the world's going,

how we're affecting
its ability to sustain.

I try to go out looking to see
how the world works.

I remember one day, I played hooky.

I was called one evening
by an acquaintance

who told me that a Bachman's warbler
had been seen that day

at a place called Poet Creek,
which is south of Washington,

on the Virginia side
of the Potomac River.

I announced to my parents...
I didn't ask, I announced!

...I was taking the car
at 4:00 the next morning.

I wasn't going to school.

The walk down the little path
that had been described to me

and then... I heard the bird.

The sound was just as it had been
described to me.

"See-see-see-see-seou!"

I knew it was a song
I'd never heard before.

I walked right to it, there it was.

And I watched it
for a couple of hours.

Even then, it was just
a mythical bird.

I don't know
another living human being

who ever saw one of those birds.

It's a memory that's about
to disappear from the area.

I loved being in the forest.

Not see people,
just be in the forest.

I got to know
the good bird-watching spots

over, I'd say a 200-mile radius.

One by one by one, I saw all those
places go under the bulldozer.

I watched the birds just disappear.

It's just nothing like it,
in the way it used to be any more.

That is the disquieting source
of a lot of my motivation.

When I was in university
in the early '60s,

we had already altered
North America so much

that there wasn't any place in it
where nature was operating

in a free-running manner,

the way it had through
evolutionary history.

I began to search for a place
that was not at all disturbed

by human activities.

You have to go to the end
of the Earth to find these places,

there are so few of them left.

That was where I felt I was really
running against the clock.

That, er,
if I didn't get there now,

I could blink my eyes,
and it wouldn't be there any more.

I went to Peru in 1963.

That's when I found Manu.

There was a brand-new national park
about to be opened

in a corner of the country
I'd never been to.

I was stunned. I was...
I just was overcome by it.

I had never seen anything
like this before.

Instead of one spider monkey
in ten years,

I could see ten spider monkeys
in ten minutes.

It was that extremely different.

Out in the forest, I encountered
two or three groups

of white-lipped peccaries a day.

The contrast just left me staggered.

It's real nature
that nobody has tinkered with.

There are not many places
like that any more.

We had to learn about
how nature operates.

That's why I settled down in Manu,
and I've been there ever since.

Ladies and gentlemen,
kindly remain seated...

Everybody has to do something.

I was actually thinking about doing
a lot of things, other than biology.

I was thinking first and foremost
about surviving.

You know, making a living, being
able to make my way in the world.

One of my former professors
at Washington State

was a consultant with
the Atomic Energy Commission,

and they were looking for somebody
to go out to Amchitka Island

and work on sea otters.

I had never worked in the ocean,
I was not a marine biologist.

I knew nothing about the ocean.

And he said, "You know,
I think you'd be perfect for this."

Two weeks later,
I was on my way to Amchitka Island.

There's a sign when you get off
the airplane there,

"Not the end of the world,
but you can see it from here."

I had this feeling
of both excitement

for the beginnings of a new life,
of doing something out there,

and also an incredible sense
of trepidation

over whether I would succeed or not.

Part of the goal was to survey
the otter population.

Another part of my goal
was to document and measure

the composition of
the marine community underwater.

The kelp swaying, all of
the invertebrates, the colour.

It is absolutely one of the most
amazing scenes that I've ever seen.

It is spectacular.

Kelp, to the coastal ecosystem,

is like redwoods
to a redwood forest,

or oaks to an oak forest.

It is an important foundation
for all of the other species.

These animals, to the degree
that there's a place

with my name on it
on the map of ecology,

they are the ones that got me there,
you know.

Without them, I don't know what I...

I mean, I might have gone
some other way, but... Yeah.

They don't know that. Huh!

In 1965, the Serengeti
was not well known.

There were hardly any tourists.

People weren't aware
of the remarkable nature

of that ecosystem, as they are now.

I got a grant from the Royal Society

to pay for me to go out there.

That is where I started my work

on the birds and the migrations
of birds in Serengeti.

All of these species,
all mixed up together.

It was just too good to be true.

I'd longed to be in such a place
ever since I was a small boy.

I realised that it has been
like this

for hundreds of thousands of years.

It was magic,
and I wanted to find out why.

The other scientists had been doing

a count of the populations
of large mammals.

Basically, the first counts
of animals in the Serengeti.

None had been done properly
before that.

They found the populations
of wildebeest,

buffalo and elephant
were all increasing

at a very fast rate.

For a large mammal, they just
don't do that sort of thing.

This is just not
what one normally sees.

Why were they increasing?

They turned to me and said,
"Would you like to study buffalo?

"Can a bird man study buffalo?"

I said, "Of course.
I'll study anything."

When that red shows,
it's ready to fire.

And if I get drug in my face
or something

coming back from the dart
hitting the animal... Mm-hm.

...and I go under, get that, um... one
here with the clear liquid, OK?

And 3ccs, inject that straight

into the person who's got the drug,
if that's me.

There's now a mystery to solve.

I've always said that science
is detective work,

but at the time we started,
nobody knew anything at all.

I didn't want to just describe it.

It's not what we call
stamp collecting.

That is, what lives here,
what are their names and move on.

It was, "Why is it like this?"

And that was very important to me
right at the beginning.

As I worked on the buffalo
over the next three years,

it became apparent to me
that I had to understand

what the wildebeest were doing,

because the wildebeest
had so much impact on the buffalo.

They were consuming the food supply
of the buffalo.

And therefore,
I had to broaden my horizons

and start looking at the wildebeest.

I needed to know the rules
that kept Serengeti together.

When I began writing, my angle in
was through the Serengeti

and the work of Tony Sinclair.

But as I dug further, I discovered
a remarkable band of...

...initially, young scientists,
who went out into the world

and just followed their passion
and their curiosity.

But Jim and Mary and Tony and John,
they don't know each other.

What will eventually tie them
together is one man.

This fellow named Bob Paine.

Bob Paine is a brand-new professor
at the University of Washington.

He's out there following
the tradition.

Observing nature,
measuring, recording.

But Bob's got a more radical idea.

Bob wants to test how things work
by changing nature.

He was exposed early on
to the general idea

that the way the world worked was
that the plants took the sunshine,

turned it into food,

and some animals ate those plants

and then some predators ate
some of those plant-eaters.

That was really the structure
of the world, from the bottom up.

That plants were the foundation
of nature, then the plant-eaters,

and then the things that ate
the plant-eaters.

But Bob wasn't sure that was
really the way things worked.

He thought predators
could be much more important.

They weren't just passengers
riding atop food chains,

they might be drivers.

Bob was really gripped
by the idea of testing

maybe predators do something more
than just simply collect

a little bit of meat
in a food chain.

But how do you test that?

You're not going to empty the ocean
of all the sharks

or take all the lions out of Africa.

How can you test the importance
of predators?

He's got to find some system
that is contained.

Almost like a laboratory.

And when he found Makah Bay
in the Pacific Northwest,

he saw these tide pools
and he thought,

"Aha! This is it."

There it was,
right out in front of me.

It was nirvana.

This magnificent array of organisms.

There were carnivorous gastropods
feeding on barnacles.

There were sea urchins
feeding on algae.

There was a lot of pattern.

Other species there
were chitons and certain snails

and certain kinds of algae.

About 15 species in all.

What was really important was
that there was one major predator.

And the predator in question
is a starfish.

They come in two colours:
purple and orange.

And you'd sort of think,
"Oh, what a lovely starfish".

But inside is the heart
of a fierce predator.

These starfish
are massive consumers.

They eat barnacles,
they love mussels.

This is the lion of the tide pool.

He found his laboratory.

Paine did
one of the simplest experiments

in the history of biology,

which was to remove the starfish

from the rocks in one place
and not at another.

Month after month, he went back
and visited that site,

tossing starfish as he needed.

And very quickly, he saw
the community was changing.

The mussel beds were expanding.

Species disappeared
from the community.

And after several years,
all that was remaining were mussels.

From 15 species...

...it just became a monoculture
of one species.

The starfish has this huge effect.

Without the starfish,
the community essentially collapses

and simplifies to a single species.

So it was the predator
that was responsible

for the diversity in the tide pool.

Instead of being organised
from the bottom up,

the starfish drives the system
from the top down.

Bob discovered a whole new way
of looking at nature.

I was excited.

I knew I'd produced
something remarkable.

I didn't know how far I would go.

Oh, and the leading ecologist
at the time,

a man named Robert MacArthur,
basically said...

"That's terrific. I believe you."

I knew I'd struck gold.

When Bob did his experiments
and removed the starfish

and other species disappeared,

well, that said, "Wait,
the starfish is really important."

But what's also crucial
is that Bob did other experiments

where he removed other components
of the system and nothing happened.

So the clear message
from his experiments

are that some animals
are more important than others.

Those animals,
he called keystone species.

Cos just as the keystone
in a Roman arch,

that when you remove it,
the whole arch collapses,

when you remove
the keystone species,

the whole community collapses.

The existence of other things
in that community

are dependent upon the presence
of these keystone species.

Trying to be a little bit
of a smart ass,

I went back to George Orwell,
Animal Farm.

And I think it's,
"All animals are equal,

"but some are more equal
than others."

It's true.

There are a lot of animals
out there,

but some play major roles,
some don't.

He laid the foundation,
he made the first observations

that were the reference point
for everyone afterwards.

The quest now becomes,
is this a general phenomenon?

Is this a rule of life,

or is this a peculiarity
of a tide pool?

This is what he's got to find out.

But he's not going to figure
this out by himself.

Bob had come to Amchitka Island,

and I met Paine the day
that he got off the plane,

and the instant I met him,
I thought,

"There's no way
I'm going to talk to this guy."

He just scared me to death.

He was very smart,
very... intimidating.

And he said, "You want to sit down
and talk a little bit

"about what you're doing?"

I told him that I was interested
in following this notion

of how the kelp forests
could support so many otters.

He said,
"It sounds pretty dull to me."

"Why don't you think about
these animals as predators?"

It just immediately occurred to me

this was a phenomenally-interesting
natural experiment.

And that was sort of the beginning
of the rest of my life.

When Bob planted the seed of
looking at the effect of otters,

it naturally occurred to me
that the way to do that

would be to go to someplace
where they didn't occur

and compare that
with where they did.

If the otters were having some big
effect, I ought to see it.

If I go to a place where
they don't occur, I ought to see it.

I had to try to find an island
where the otters had disappeared.

What I understood about
the distribution of otters

was that they occurred throughout
all of the islands to the east,

but they weren't on Shemya
at that particular time.

Shemya lit up like a red flag.

It was the obvious place to go.

I stuck my head in the water at
Shemya and I thought, "Oh, my God.

"This is unbelievable."

I'd never seen an urchin barren
before going to Shemya.

From having watched otters
for extensive periods of time,

I knew they ate a lot of urchins,
but it never really occurred to me

until I actually saw a system
where otters were gone,

that the effect was massive.

Kelp forests,
like forests everywhere,

provide habitat for other species.

A place to escape predators,
a place to lay their eggs.

Just like birds,

just like many other species
in terrestrial forests.

The urchins ate all the kelp.

Otters eat urchins,
urchins eat kelp.

You take otters out of the system,
urchins become abundant

and they eat all the kelp.

You can't have a kelp forest

without having sea otters there
to protect them.

I sat there all night long.
I didn't sleep at all that night.

All I did was write.

I think I had some sort of visceral
sense that this was a major deal.

I've never in my life felt
such enthusiasm and excitement

as I felt at that moment.

I'm coming to Oklahoma
pretty inspired by Bob Paine.

I was a student of Bob's in the
'70s, so, under Bob's instruction,

had read the amazing papers
of Jim Estes

that had just come out
a few years earlier.

But to be honest, I was doing
something completely different.

I wanted to see what fish did,
because I like them.

It was really getting a chance
just to watch fish.

As opposed to having to prove
that fish matter,

I just wanted to see
what they were doing.

But you look down into
this particular stream,

and what we saw was
these barren pools

interspersed
with these emerald-green pools.

So, what's going on there?

We did get into wet suits,

and the first pool did happen to be
a green pool.

You could just look through
the waving fronds,

and lurking in the forests
are these big, large-mouth bass.

There weren't many prey
in these bass pools.

They'd cleaned out the prey.

And then you go to the next pool
and it's just about as deep.

It was completely barren and sandy.

And there are these
little thin minnows

that were grazing algae away
down to the bare rock.

We didn't even need to snorkel to
see that there were no bass in it.

I knew it was a Bob Paine/Estes'
situation when I first saw it.

All you have to do is
the experiments that Bob advocated.

We took a green pool,

split the pool into two halves.

We netted out the bass

and then we added minnows
just to one side.

And we sat back and waited.

Doing manipulative experiments,
or even thinking this way,

is not widely practised.

It's important to try to convince
people who are not willing

to entertain another view

that they should have a closer look.

There's this wonderful sense
of beauty, or fascination of nature

and then the fun of doing
a kick-it-and-see experiment.

In five weeks, on the side
where we've added minnows...

...they'd chewed it down.
It was totally barren.

Just takes one bass in a pool
the size of a large room

to either terrorise the minnows
and make them leave,

or eat them up and turn it
from barren to green.

Bass are keystone species,

just in the sense that Jim's
sea otters or Bob's starfish are.

It was pretty obvious
that predators do matter.

This is Bob Paine's
keystone species,

as realised in a little
prairie stream in Oklahoma.

Mary Powers' work in streams,

Paine's work in intertidal

and Jim's work in the environment
of the ocean,

they did seem to work in a wide
range of aquatic environments.

So at that time,
I started daydreaming.

"How could I expand on this?"

What I needed was to do
an experiment, but on land.

That meant finding fragments
of forest without any predators,

but with everything else
still there.

I didn't know of any such place
until I learned about Guri,

and that's... that's where
it all began.

Guri was a huge lake in Venezuela

created by the damming
of the Caroni River.

It produced lots and lots
of islands.

Mostly without any predators.

The top predators,
the mountain lions,

the jaguars, harpy eagles,

they'd already disappeared.

Everything that should have been
there was there,

except for the top predators.

It was the perfect system,

so that you could see
what the response

to removing predators would be.

When I climbed up and walked
into the forest,

it looked like a hurricane
had been through there.

Wow!

There were some islands
that accumulated

extremely high densities
of leafcutter ants.

On the mainland,
leafcutter ants are controlled

by the species of army ant.

Without them, they're 10,000 times
more abundant

than they would be on the mainland.

The foliage had been stripped
off the trees so many times

by this multiplicity
of leafcutter ants...

...all the storage reserves
of the trees have been exhausted.

They'd leafed out
and had been defoliated,

and leafed out again
and been defoliated.

A tree can only withstand that
so many times, and then it dies.

That is absolutely a response
to the absence of predation.

They start out
this beautiful green forest,

and in 20 or 25 years,
be reduced to dead rubble.

Look at that.
Look at all those trees. Mm.

This one has died,
that one has died,

this next one has died.

That one has died.

The overall impression is mortality.

We saw it happen on island
after island.

It was repeated in different ways
with different actors,

but it always got
the same end result.

It's all predation-driven.

You remove predators,

that leads to the deterioration
of the whole system.

What Jim and Mary and John
all confirmed

in really different systems was that
predators were really important.

That's a totally new way
of looking at the world.

It overthrows preconceptions
about the picture we had of nature,

it reveals completely unexpected

hidden connections
between creatures and nature.

But that's just the beginning
of the story.

The first glimpses of the chains
of connections between species.

The real question is,
how big, how deep,

how far do these connections
extend across our planet?

By the early 1990s,
I was of the mind-set

that otters had reached
historical levels

and that they were stable
at those high densities.

If someone had told me at that time

that the system
is going to collapse,

I would have thought,
"This is insane.

"How could that possibly be?"

But I knew that there were
8,000 otters at Amchitka Island

and five years later,
they're almost all gone.

I was just stunned.

It was like going
to a whole different ecosystem.

It's a dense kelp forest
and then, all of a sudden,

there is this abrupt change.

That was the case across
the whole Aleutians.

50,000 miles of coastline.

It was a massive decline.

We're talking about
the loss of tens,

or perhaps even several hundreds
of thousands of otters.

A decline of 95-99%.

And not a single corpse or carcass
to be found anywhere.

I knew they weren't dying
and crawling up on the beach

and starving to death,
or dying from some disease

because we would've found them.

So then the question became,
"What happened to the otters?"

It was such a dramatic event
that I had to try to figure it out.

The most striking thing that we saw
was that there were killer whales

all over the place around
these islands at that time.

I would see a killer whale,
on average,

probably once every three or four
years in the '70s and '80s.

Starting in about 1990, I'd see them
three or four times a day.

Not only did we see killer whales,

but we started seeing them
eating otters.

One day, our field crew was out here
and there was a group of otters

that were hauled out on these rocks
immediately ahead of us.

The observers noticed
off in the distance,

three killer whales
that were coming from the north.

And the killer whales swam up
in tandem, all three of them,

right to about here.

Two of them dove

and once they emerged again
on the far side of these rocks,

the third killer whale
charged the rocks

and created a big wave that washed
the otters off into the water

and the killer whales that were
behind grabbed one or two of them.

That behaviour has been seen
in killer whales with other species.

We began to suspect that killer
whales were the driving force

or the cause of the decline
of sea otters.

Once we came to that conclusion,

that it was declination
by killer whales,

then the next question was,
why did that happen?

What made them do this?

I also was aware that other species
had declined in that system,

and in particular,
Steller sea lions.

It wasn't a big jump in logic
to imagine

that the sea lion populations
had declined for the same reason.

That orcas had simply driven
their numbers downward.

I was in my office one day
and actually plotted the graph,

and I remember sitting there,
looking at this thing, thinking,

"Oh, my God, this is amazing."

It was whaling that started
this whole business.

In the North Pacific Ocean,
where this event occurred,

industrial whaling began
post-World War II.

And it progressed
to the early 1960s.

By the early 1960s,

the great whales in the
North Pacific had been decimated.

Taking the great whales out of
the North Pacific, which are large

and highly nutritious
to a consumer like an orca,

really shocked that system.

That would force the killer whales
into broadening their diet.

It would all fit together.

Whales got stripped out of the
system, killer whales got hungry,

they started feeding
on other things.

First thing they ate was
harbour seals. Cleaned them out.

Next thing they started feeding on

were Steller sea lions.
Cleaned them out.

Went to the otters, cleaned
them out, and that's what we saw.

These effects seemed to sweep
through the system

and impact virtually everything.

From salmon, from sea birds,
from bald eagles.

The whole system collapsed.

That was sort of a revolution
in my scientific thinking

with recognising
that nature is connected

over such vast scales of space
and time in such major ways.

It was very clear what had happened.

The cause was simply
the removal of great whales.

People were the cause.

Holy shit!

A set of dominoes that we set
in motion 60-70 years ago

have come all the way around
and bitten us in the ass.

These systems are hundreds of
thousands, to millions of years old,

and we've come in
and pulled them apart.

These are whole new eyes
for looking at the world

and figuring out what's going on.

Why and how is it changing?
What have we done?

What humans have done is take nature
apart layer after layer.

It's very much like
a thread in a tapestry,

that if we pull a thread,
the whole thing can come unravelled.

There's widespread evidence
that the world is changing.

We're experiencing extinction,

we're experiencing declines.

Even national parks that were
supposed to conserve biodiversity

had lost species.

Why does that matter?

Because it matters beyond
the emotional loss of the species.

If you lose the wrong ones,
if you lose the keystones,

you're going to see
very big changes everywhere.

It was after we understood that

that we coined the word
"downgrading" to describe it.

Much of the world that we see today
has already been downgraded.

Almost any place that we've touched
is downgraded.

For a host of reasons.

And the domino effects are probably
what scares us the most.

We thought we were only removing
these inconvenient, scary animals,

or the large, tasty things
out of the ocean.

But in fact, we're having all
of these strong, indirect effects

on other creatures
and other systems.

There is a risk that we get used to
a downgraded landscape as the norm.

A treeless landscape in Scotland
is not a baseline,

it's a sickness. It's a cancer.

Cancer is the uncontrolled growth of
something that becomes pathological.

Algal blooms on lakes are a cancer.

They're running unchecked.

And they end up suffocating out
other forms of life in the lake.

In West Africa, you have baboons
overwhelming areas

because top predators
like lions and leopards

have been exterminated.

In America,
deer are destroying the forests.

Even national parks are downgraded.

We've only just realised
after 70 years without wolves,

Yellowstone is not
what it's supposed to be.

I know we like Bambi,
but the reality is

elk herds and deer
are running unchecked,

and they've had devastating effects.

It's not normal.

This is what this band
of scientists illuminated.

These hidden interactions,
the stuff that has escaped awry,

the stuff that wasn't obvious to us,
that we didn't suspect at all.

Most of us can't see downgrading,
even if it's right in front of us.

I can see it, I'm not sure
just anybody could see it.

Science can tell us what's happening
when the naked eye can deceive us.

Remember, we found at Guri

that with no predators,
the herbivores increase,

the ants literally
ate down the forest.

We're seeing the same thing here.

It's not ants, it's deer.

But out of control,
they can lead to the same

rather disastrous consequences.

The deer have reached
plague abundance.

And it's the deer
that create this effect,

as if you had taken a hedge clipper

and gone along on the underside
of the branches,

removing everything
between the ground

and what we call a browse line.

If this forest were whole and
natural and reproducing normally,

you wouldn't see me from the camera,
there would be things in between.

But you can look way out there
and there's no obstruction.

The visibility is 100 feet,
or 200 feet.

It should be maybe ten feet,
or 15 feet.

That's the difference,
there's nothing in the middle.

The trees overhead,
a few little plants on the ground,

but the middle is missing.

This forest is clearly
on the downgraded side

because it's a disappearing forest.

These big old trees, they're
the last of their generation.

When those oak trees die off, there
wouldn't be a forest there any more.

The end point
of excessive deer browsing

is not just the loss of the forest,

it's the loss of
the whole forest system.

All the other things
that live with the trees.

I remember a better world, and now
I see things going in a direction

that disturbs me enormously
every day of the week.

I can't stop thinking about it.

Where are we going?
What's the future going to be?

Will there be any nature at all
in the future?

We've broken nature
all over the world.

But this could be
the part of the movie where,

"Oh, my goodness, this is the gloom
and doom you hear ten times a day."

The headlines are all too familiar.

You know, we're doomed,
we screwed it up, we're awful,

nature is going to disappear.

We shouldn't be getting used
to these things.

They're not the way they need to be.

They're not the way they should be.

Downgrading is a fact.

But is it our destiny, or is
our destiny still in our control?

Can a downgraded system be upgraded?

Is that even possible?

When Tony Sinclair started working
in the Serengeti,

he didn't realise it at the time,

even the world's most-famous
national park was badly downgraded,

but it was changing.

We know that 120 years ago,

an epidemic called rinderpest hit
the wild animals of the Serengeti.

Rinderpest is a disease of cattle,
it is not a disease of wildlife.

It's very similar to measles.

It kept the wildebeest
population down

for the better part of 70 years.

That was a definite
form of downgrading.

The 1960s veterinarians
successfully managed to eradicate

rinderpest in most of Africa.

We realised,
because rinderpest had disappeared,

that that was the reason we saw
the populations increasing.

When I first started,
the wildebeest was somewhere

around 250,000 animals.

By the time I'd finished three
years, there was 400,000 of them.

And everybody thought, "Well,
they must have reached their limit."

The next time we looked,
it was 700,000.

Four years later, they had
doubled again to 1.4 million.

We had a world record,
the largest population

of ungulates in the world.

I sent a message to a colleague
of mine what the number was.

He wrote back.

All it said was, in reverse,

"Fan-fucking-tastic."

The meeting in 1982 was our first
opportunity to tell the world

about what was going on.

That's the end of my part,
thank you very much for listening

and thank you
for the contributions...

You know, we'd just broken
the record.

Biggest population in the world,
and that was quite something.

Our next speaker
is Mr Tony Sinclair.

And this was an eye-opener
for all of us.

I'm here to share the success
story of the Serengeti.

I made this presentation
with a lot of enthusiasm.

...1.4 million.

There was a deathly hush.

I wasn't expecting
that reaction at all.

Everybody thought we were
being irresponsible

to allow this to happen.

Surely you can understand this?

We should have been culling
these animals

because they'll overgraze
the place, destroy the habitats

and they were going to cause
a collapse of the system.

But why should humans
have to interfere?

These systems have been in
existence for millions of years

without having humans required
to interfere for them to persist.

We decided we were going to stick
to our guns and we prevailed

upon the park authorities
not to give in to culling

but to wait and see
what was going on.

If we were wrong,
we could be destroying

one of the iconic places on Earth.

I returned, we did another census
and discovered that we had got

the same result as the year before.

1.4 million.

Now, this was the very first time
that had occurred and suggested

that the population
was now levelling out.

But we had to come back
another time, one more time,

and, two years after that,
we came back

and found we got the same answer.

And, at that point, we knew
that the system had levelled out

of its own accord, and there was
no damage to the environment.

It was not collapsing.

And then, to our surprise,
we found that the system

was actually repairing itself.

All of a sudden, things started
to reconnect with each other.

Wildebeest produce dung out
on the short grass plains.

That puts fertiliser into the soil
and that fertilises the grasses.

The grasses then become
highly nutritious.

And, by eating up the grass,
there was less fuel

and therefore less burning.

And that allowed the tree
populations to increase.

Tree populations that probably
hadn't occurred since the 1800's.

Those trees provided more food
for elephants, for giraffes

and for many, many bird species.

And then there are many
more predators because

there's more food for those, too.

All these components were
interconnected and they were all

responding to the wildebeest
population.

The wildebeest in their huge numbers

were determining everything else
inside the park.

I realised that wildebeest
was a keystone.

Bob Paine had always assumed
the keystones had to be a predator,

but we realised that a keystone
could actually be herbivores.

We were seeing a recovery,

an upgrading of the whole ecosystem
for the first time.

Even though wildebeest have been
taking a pounding for 70 years

from this virus, that there was
still the resilience there,

still the capacity there

for the population
when that was lifted... to explode.

And that when it did explode,
the capacity

was still there in the Serengeti

for the Serengeti to change
in profound ways.

More trees, more giraffes,
more songbirds, more butterflies,

more dung beetles, more and more and
more and more across the Serengeti.

Tony's work is marvellous.

I was delighted! Because here
is recovery, here is upgrading.

But it's a long, long process.

It's taken 50 years.

We're almost 60 years down from
Bob Paine's work with the starfish.

I think we're finally arriving
at a much better place,

but it has taken that long.

That's what gave me the idea
for the White Oak conference.

John approached me about getting
a bunch of people together.

The idea was to invite people
that were prominent ecologists

in various major ecosystem
types around the world.

It was only by listening to each
other at White Oak that we realised

we were talking
about the same thing.

That is one of the major...

Whether it was terrestrial
or aquatic,

whether it was arctic or tropical,

it was all working in the same way.

Every person that was there,
there wasn't anyone that argued,

"I don't see this in nature."
Not a single one of them.

The White Oak Group published an
article in Science magazine titled

Trophic Downgrading Of Planet Earth.

Bob Paine was the first one
to show it.

Throw away the starfish,
and the biodiversity collapses.

The starfish is critical.

It may sound strange,
but that is the way nature works.

Everywhere.

There are rules.

No-one can escape it.

If you have to fix something,

you have to know what's broken.

That's what rules provide.

And so our challenge will be
to understand how we can upgrade

systems that have been downgraded
much farther than Serengeti.

What we need to do is put
the starfish equivalent back in.

It's critical that we replace
species that are central

in holding ecosystems together.

Nature could heal itself
if a keystone is released.

It is a place where you can get
an enormous bang for the buck.

We found the rules.

We found the rules, how systems
work, how the world works.

Now you've got discoveries
that connect with one another

and truly change our view
of how the world works.

And now you've got a chance
for scientific revolution.

And what does this mean
for you and me?

It means we can use this knowledge
to upgrade the places around us

and, like in the Serengeti,
the potential is enormous.

I'll show you something
really amazing.

The high plains of Argentina,
where pumas are allowed to return,

the grass grows and creates habitat
for all sorts of creatures.

One picture, a lot of hope.

Wolves have been missing
from Yellowstone for 70 years.

There was no reason for biologists
to be confident.

If you put wolves back in there,
then anything might happen.

But we put wolves back in
and the willows rebound,

the aspen are doing better,

the cottonwoods thrive,

beavers come back.

Oh, my goodness!

This is an incredible photo.

This is an enclosure
that was built in Scotland

that shows you the impact
of the grazers and what Scotland

would look like without them.

Many of the trees in
Yellowstone need wolves.

The trees in Scotland need wolves.

But this isn't about making
the world pretty.

This is about making the world
productive and functional.

And the body of knowledge,
the number of examples, is growing.

For instance, in the Upper Midwest,
there are folks adding keystone fish

back into lakes and flipping them

so that murky green lakes
become clear.

Where the otters are returning
to the Aleutian Islands or anywhere

on the west coast of North America,
the kelp is coming back.

In rice paddies,
spiders are keystones.

So, if you want rice to eat,
protect the spiders.

All over the world,
people are trying to improve things

that were degraded in past decades.

We've seen it's possible
in so many places, in so many ways.

So very modest ambitions
by individuals

driven out there into nature

has paid off in a grand vision
of how the world works.

Humanity, ultimately,
is a driver of everything.

These keystones are really important
to the distribution and abundance

of species, but all of that
is under the control of humanity.

Humans are hyper keystones
in the sense

that they are all-controlling.

They are all influencing
these things.

The behavioural change in humans
that I think is most important

is changing intolerance
to tolerance.

It's not an idea that's really been
part of our history.

We exploited and killed everything
that stood in our way.

We have to get to tolerance,

and then I think
we can make some progress.

I think many of us are seeing
how fast humans are changing

the world, and humans clearly
don't want a destroyed Earth.

But I don't think you get
depressed if you're fighting

with some hope in your heart.

July the 1st, last year, was my 50th
anniversary in the Serengeti.

Oh, my goodness me! What is this?

Happy 50th!

It was nice to see
the younger people

wanting to be there for the oldies.

I want to do... not only thank them,
but to encourage them

that it's now over to them
to keep this up.

What made this group so special
is that each of us has a...

pretty private part of the world.

Some large, some small,

which we understand and love.

By understanding nature,

you make managing
the recovering nature

that much more of a positive
experience for everybody.

Nature is not a very peaceful place.

You know,
the sooner you recognise that,

the better we can understand it,

and, certainly in the longer term,

the better we can manage it.

And perhaps even survive it.

♪ It's a mystery to me

♪ We have a greed

♪ With which we have agreed

♪ You think you have to
want more than you need

♪ Until you have it all

♪ You won't be free

♪ Society

♪ You're a crazy breed

♪ I hope you're not
lonely without me

♪ When you want more
than you have

♪ You think you need

♪ And when you think more
than you want

♪ Your thoughts begin to bleed

♪ I think I need to find
a bigger place

♪ Cos when you have more than you
think, you need more space

♪ Society, you're a crazy breed... ♪