Areas of eastern and southern Africa are currently in the grip
of a vulture crisis.
Where vultures are being inadvertently poisoned in their thousands.
Seven of Africa's 11 vulture species,
are now listed as endangered or critically endangered
with some having fallen by as much as 97%
within the last 50 years.
But the birds themselves aren't the intended targets
and the consequences have been known to have a devastating impact on humans.
Too understand why we need only to look to India,
where the effects of a near-total vulture extinction
are still being felt today.
So how does killing vultures endanger human life?
Africa is home to at least a quarter of all known species of mammals
and 18% of the human population.
However, this relationship is not always harmonious.
Conflicts between humans and animals
are among the greatest threats to the long-term survival of many species.
Lions and elephants are often targeted by humans,
not for hunting but because of threats to their livestock,
crops and communities.
In Kenya and Tanzania,
the Maasai people have lived a nomadic lifestyle for centuries.
Earning their livelihood from herding and protecting their cows.
But as governments have allocated more land
to game reserves and national parks
and the climate crisis has made weather patterns
increasingly difficult to predict,
the Maasai are now living a more fixed lifestyle.
At the same time as numbers of prey decline,
lions and other predators are finding it harder to find food.
which means we're seeing more cases than ever before
of lions, hyenas and wild dogs eating Maasai livestock.
As a result, the Maasai
and other rural pastoralists across the continent,
try to protect their cattle by poisoning the carcasses of dead livestock
with a pesticide called carbofuran
in order to kill predators who return to feast.
This is an issue that's been growing over the past decade
and the unintentional victims of this poisoning are vultures.
Over a hundred vultures might feed on one poisoned lion carcass,
which means they're dying in swathes.
As of 2015 poisoning accounted for well over half
of all unnatural vulture deaths in Africa.
And we know this can have a fatal impact on humans,
because it's happened before, in India.
In the early 1980s
India had an estimated population of 40 million vultures,
but by 2007 the total population fell by 99%.
The cause was the use of the anti-inflammatory drug diclofenac,
being used to treat cattle.
Because cows are considered sacred in India,
when they die naturally their corpses are left unburied
to be fed on by vultures and other scavengers.
It was eventually found that diclofenac caused kidney failure in vultures.
The drug was banned in 2006,
but not before vulture numbers plummeted
paving the way for feral dogs to surge and become the main scavenger.
It's estimated that the extra 5.5 million feral dogs
were responsible for an additional 47,000 human deaths from rabies.
Though much maligned, the vulture actually performs a great function
as nature's janitor.
By rapidly cleaning up and recycling dead animals.
A vulture can eat nearly a kilo of meat in a minute,
a wake of vultures can strip an entire zebra in 30 minutes.
This speed leaves very little time for bacteria and disease to develop,
which stops rotting carcasses contaminating nearby water and livestock.
Because unlike other scavengers the vulture's stomachs contain an acid
that's 100 times stronger than humans,
which kills deadly diseases like, Anthrax and rabies.
The decline of vultures worldwide
also poses serious environmental risks,
associated with decomposing carcasses releasing greenhouse gases
most of which would be prevented if vultures disposed of them.
It's estimated that the 140 million vultures worldwide
could be preventing up to 60 million tonnes
of CO2 emissions per year.
An amount comparable to the emissions of North Korea.
In recent years there have been increasing arrests
for lion and elephant poisonings.
Zimbabwe has brought in tighter laws to restrict poisoning by elephant poachers,
But in Kenya the government has refused to ban
the easy to access pesticide carbofurane.
A subsequent ban of diclofenac by India and surrounding countries,
as well as the introduction of breeding programmes,
has seen vulture numbers slowly rebound,
which shows a clear path to recovery.
Unless governments step in to protect the delicate balance
of these human and animal ecosystems,
we could lose vultures.
And the true consequences of that
could be much worse than we could ever predict.