The vulture has a pretty bad reputation.
Forever chilling...
like a villain.
"Very funny."
A most evil character.
"So I'm up here in the mountains of Bulgaria,
where these guys are the central characters of the story.
And they're the good guys –
but they're carrying a pretty heavy burden on their wings."
"You just move the vultures and
everybody benefits from that."
Around the world, groups are bringing vultures back.
As well as other wildlife from lynxes to beavers –
even Eurasian wolves.
And the goal is for them to play a
key role in mitigating the climate crisis.
"But how are a few birds supposed to make such a big change?
And what does that have to do with the climate?"
We're living through what's being called the sixth mass extinction,
where up to 150 species are going extinct every day.
And this loss of biodiversity is already threatening parts of our own existence.
From insufficient pollinators to help us grow food
to losing fish that keep water clean.
"Around the world many groups are trying
to reverse this and up on that mountain
one of the biggest such projects is underway."
I'm in the Vrachanski Balkan Nature Park in
western Bulgaria, accompanying a group of bird handlers.
They're working on a potentially
game-changing concept called rewilding.
Here, it involves releasing vultures into the skies.
The idea is for this to have a knock-on effect on
the whole ecosystem.
We'll get to how that could all work in a minute.
But first, meet THE vulture-man in these parts.
Hristo Peshev, who's doing a PhD on these infamous birds.
"So how many birds are like actually in this area now?"
"Because the birds move constantly between different range
reduction areas between different colonies,
you can never say but maybe around 100."
"Oh yeah? Out of these like 100 vultures how many
have you released?"
"All the birds that usually live in the area, most of them,
are released by us."
The project began in 2016.
Today, 13 young vultures are sitting in an aviary
at the top of the mountain, waiting to be released.
"I mean, they're some of the biggest birds in Europe
but up close, they're massive."
"Where have they come from?"
"These are native Spanish birds
because they need to adapt, they need to
meet the other birds in the area, they need
to know the area. So they are watching.
They are brought here and now they start to think of this place
like their home."
There are four species of vultures in Bulgaria,
but the Cinereous vulture and the Griffon vulture
are in the aviary today.
They're all scavengers meaning they feed on the bodies of dead animals.
The vultures in the Balkan ecosystem go together like bread and butter.
The extensive grasslands, wildlife, shepherds
and vultures evolved together here
over thousands of years, supporting each other.
Every time a wild animal or sheep or cow died, the vultures stepped in.
Hristo's grand-uncle described what it was like in the 1930s.
"He told me that when there was a dead cow,
the whole sky became black from vultures.
They covered the cow. And his grand children –
when before we started this reintroduction –
had never seen a vulture.
Because things changed. When Bulgaria was under the
communist regime in the second half of the century,
the state encouraged putting poison in dead sheep,
so that wolves and other predators that
ate them would be wiped out and the shepherds
would be protected.
But when vultures tried to feed on the carcasses
of the poisoned animals, they became the accidental victims.
And then a double-whammy.
Later in the century, the industrialization of sheep farming
meant that the once open grazing sheep, moved indoors –
and died indoors –
and vultures lost access to a large part of their food supply.
These are still huge challenges for the birds –
along with hunting.
Their population went down
from possibly hundreds of thousands of vultures in the 1900s,
to one breeding pair of Griffon vultures
and zero Cinereous vultures later in the century.
So now the team is trying to bring them back.
But it's risky. Not every bird released will survive
in the face of so many challenges.
Hristo first picks up a female Cinereous vulture.
A bag over the head keeps her calm,
and a tag helps him keep a track of her progress.
But to understand the cascading effect vultures
can have on the ecosystem here,
we've really got to understand what an ecosystem even is – and how it functions.
"Ecosystem comes from the Greek word Oikos,
which means household."
Henrike Schulte to Bühne studies
conservation science in the Zoological Society of London.
So I brought her in to help me out.
"And I think in ancient Greece that would include like, you
know, the main family and it would
include like servants and slaves,
and it includes the animals and includes
the houses, like the physical structures."
Think of it like a network of living species of plants
and animals and non-living structural
components like soil, the nutrients in it, water and air.
Each has a role to play.
Let's talk about grasslands.
"So there are some basic principles like
plants and grass support animals that eat them – like herbivores.
They graze, trample, and poop, which stimulates the growth of newer, healthier grass.
"And it also helps support other species
like insects and reptiles.
But you can't just have herbivores because then they would eat up all the grass.
So you need carnivores that
check the population of the herbivores."
Ecosystems are very complex but generally,
when there are a lot of species playing their parts
and they all have resources, we call that ecosystem healthy.
Energy, nutrients, and water are passed through the system
and these cycles determine how much carbon is absorbed,
how much it rains, and the local weather over the long term.
AKA: they help determine the climate.
"Since the last ice age, roughly speaking, there's been this
suite of species around and they've always sort of vaguely
interacted with the same neighbors.
Species develop ways of coping with drought and they
develop ways of coping with like diseases
and stuff like that. So and that doesn't mean that...
there might not be like local extinctions but sort
of on the whole like things could sort of –
because, you know, if you don't develop ways of coping with
like climatic extremes and stuff,
you're no longer going to be here."
A large number of relationships
between diverse species help keep the entire
ecosystem from the living to the non-living
and the climate, stable healthy and resilient.
But as human habitations expand and change habitats,
many of these relationships are breaking down.
Sometimes that's still okay and the ecosystems cope
resiliently – but not always.
"Let's imagine our ecosystem is like a friendship group
and it's five people and all of those five people
have like the same kind of level relationship to
all other people.
And now let's imagine that one of those people goes on holiday,
for like eight weeks. Probably the social activity of that
friendship group is not gonna alter much
because yes, one person has left, but actually
there's a lot of other interaction that happens.
And now imagine like the same friendship group of five people
but there's one person who's like maintaining all the friendships,
and the other four people don't really like each other –
because that happens. And if that person goes on holiday,
there's going to be zero games nights
like in that friendship group."
That one friend could be the tiger in a forest ecosystem that
keeps the deer in check.
Or our heroes the vultures.
They're like the local recycling department.
It's very important they exist to clear up rot
which stops the spread of disease.
And more importantly for the ecosystem:
as the birds break down
organic matter, they send nutrients back into the soil
that keeps everything healthy.
Here, in the Bulgarian grasslands, the decline of
the vulture has meant that diseases can spread faster
and the grassland itself has become weaker.
As soil degrades, grass is affected
and this effect knocks on to other living
and non-living components in the biosphere.
And this is the big problem globally.
Weaker grasslands and broken cycles impact the climate.
Along with forests, croplands and wetlands,
grasslands in the EU absorbed 263 million tons of carbon dioxide equivalent per year.
That's around four and a half times the total annual emissions of Bulgaria in 2019.
The EU is looking to restore more land to raise that number to over 310 million tons by 2030.
Globally, UNEP has called for restoring land the size of Canada over that period.
So each release is important.
"So what do you hope will happen to this bird?"
"I hope that will be as usual. We'll just release it,
stay two, three days around
knowing the surroundings and then meet the other birds on the cliffs
and start to live in this area."
I step away so the bird can have its space to fly free –
it's the moment we've been waiting for!
A bit underwhelming, but she's off.
Apart from vultures in Bulgaria,
over 70 countries around the world are now bringing back wildlife,
including bison to woodlands, beavers to rivers
and elephants to grasslands.
Rewilding, as opposed to conserving a species within a fenced national park,
or planting trees in a small area,
is seen as a low-cost and far-reaching method to restore entire habitats and beyond.
With the tracker, Hristo watches as the birds visit Romania, Ukraine and even Moscow,
potentially setting up new colonies there and cleaning up what needs cleaning.
Having more wildlife around also has other social benefits, like ecotourism
as well as just admiring the aesthetic beauty.
But it's been controversial because it can and has gone very wrong.
Like it did in a project in the Netherlands.
Horses and deer were released. But without predators,
they ended up overgrazing shrubs and trees.
Wild birds declined and the ecosystem deteriorated.
Not to mention most grazers starved to death or had to be shot.
In other instances, species have been introduced, intentionally and otherwise,
which outcompeted and ended up killing local species.
The translocation of the desert tortoise in the US,
caused further declines in population,
as they had insufficient support systems.
To ensure their survival the team here have set up vulture restaurants around the country,
for the now free vultures to visit when they need to,
as well as for those still in aviaries.
A Michelin star menu for them, and zero stars from me.
Hristo and I picked up a cow and a sheep that died of natural causes at two nearby farms.
"It's a nice final resting place for the cow."
"Of course. Eaten by the vultures and bring to the heavens."
I guess this is why everybody thinks these guys are creepy.
The restaurants are a temporary solution.
The team hopes that farmers will set up
their own feeding sites.
Partner projects are also introducing red deer into mountains here.
So vultures will have enough to eat without human intervention someday.
"We don't know what will happen in 100 years,
200 years. One way is total destruction,
cataclysm, global warming. And the other way is we change,
and we start to live with nature and if
they disappear now, there is no opportunity for
the future generation to have nature. They will have nothing.
We are the people that helping for them to survive a
little bit more to reach this goal."
There are now over 300 vultures in Bulgaria
and last year, the first wild vulture chick was
born in 50 years in these mountains.
But equally, dozens have ended up being poisoned or died from starvation,
exhausted from flying around searching for food.
"Somewhere up on those cliffs, new birds
are slowly settling into their new home
and older ones are probably mating or even having offspring.
Or it could all be going completely wrong.
So the question is, is all of this effort worth it in the end?"
Rewilding doesn't guarantee the survival of the species or the systems.
But it is a chance to transform entire landscapes and help the climate stay resilient.
"I never imagined that I would be standing in a
field of carcasses where vultures feast.
But if you want to join us in more weird and really interesting places,
come back and watch every Friday."