Bats have a scary reputation
even though most of them are actually harmless
But there is one species that causes big problems:
The common vampire bat.
In Latin America, vampire bats are destroying lives and livelihoods
They prey on pigs
on calves
on children
and sometimes, sick bats carry rabies
It's a horrifying disease - once someone exhibits
symptoms it's too late to save them.
Ranchers want the government to exterminate vampire bats.
which raises a question:
Should humans completely wipe out this deadly species?
♫ GOOD QUESTION ♫
To try and wrap my head around this problem
I headed down to a major battleground in the human vs. vampire bat war.
Panama
This country is bat paradise
"The entirety of the United States has about 47 species of bats"
"And Panama, which is much smaller, has 120 species of bats"
This is May Dixon - she's something of a walking bat encyclopedia
And she told me there's a lot of confusion about bats.
"A really huge one is that people think that all bats are vampires"
And that couldn't be further from the truth.
The vast majority of bats don't drink blood and don't actually harm anyone.
To prove it, May insisted I meet some.
"So what kind is this?"
"I'll tell you in a moment I can't tell yet"
"So this is a Jamaican fruit bat"
"You want to feed it?" "I can try"
"Wow ... thirsty!"
You wouldn't want to kill these bats, and not just because they're cute
Bats are the secret heroes of the jungle
"See ya later"
You've got fruit eaters like the Jamaican fruit bat
that spread seeds and replant the forest
Bats with long tongues that drink nectar and
pollinate flowers
"Including agave - which is important because
without it we wouldn't have tequila"
Bats who use echolocation to catch bugs
the bugs that bite us and eat our crops
We met lots of amazing and useful bats - but ...
"None of those are vampire bats, no not one"
And that's the species I'm really interested in
Luckily for me, May works with a guy who keeps a vampire bat colony in a big shed
Yep, that's a bucket of cow blood
"So each night, each bat is taking about a tablespoon of blood"
"which is no that much"
"but when you have 36 bats it adds up"
"I often think of vampire bats as kind of the super bat."
They're stealthy mammal finding, blood drinking little ninjas
Their noses have these infrared heat sensors so they can detect warm veins beneath the skin
"They have low frequency hearing"
It's like they're specially evolved to hear the breathing of big animals
"They have these canines for cutting away hair and feathers
And their front biting teeth are so sharp - prey don't feel a thing,
And unlike most bats ...
... they can run.
These guys are great at what they do but as far as we know
they don't play any important role
The jungle would be just fine without them
Now, for thousands of years, vampire bats did their thing and weren't much of a problem
There weren't that many of them, and there were enough peccaries, tapirs and capybara
to satisfy their thirst for blood.
Then, everything changed.
In 1493, Columbus brought a new blood source across the sea
Cattle!
Colonists destroyed jungles and replaced them with pastures.
The herds multiplied - and vampire bat populations shot up with them.
And that's when they started causing problems for ranchers.
This is still still going on today This map shows where trees have disappeared
in just the last 15 years
In many of these places ranchers are trying
to make a living on the very edge of vampire bat territory
The town of Pueblo Nuevo is a perfect example
... so decided to pay it a visit
Here, life revolves around softball, fishing, and most important - the vampire bat's favorite food.
Where are the bats?
They're waiting for sundown in the hills just outside of town.
A guide named Austin Garrido agrees to take me into the bat caves
"They're this view into an alien world."
There are so many kinds of bats here but the vampire bats shrink away from our head lamps
We have to use infrared light to get a good look at them
Every night, when darkness falls, the vampires leave their caves to search for blood.
Rabies costs farmers in Latin America $30 million dollars a year and kill dozens of people.
They explained the Panamanian government actually does try to poison the vampire bats here and there
They spread a toxic paste on the back of a bat
and when that bat returns to its roost
the poison spreads through the whole colony
But here's the thing - nearby bats just come in to take their place.
And new research suggests that all this may just increase the spread of rabies.
Now in an ideal world - you'd find a way to just get rid of the rabies virus itself
But that would take a hugely expensive vaccination program - you'd have to get all the people,
cows, pigs, even the bats!
So as far as the ranchers and the government are concerned
The best thing to do is just keep on killing vampire bats
Try and drive them to extinction!
Which brings me back to our question.
Back in town, I asked Gerry what we would lose if we did wipe out vampire bats.
"When I give talks to the public one of the most common questions I get is
'How are vampire bats useful to us?'
"And I tell this story about the anti-coagulant
"that vampire bats have in their saliva"
It's like a drug that keeps the blood of their prey from clotting
"It's a better chemical anti-coagulant for treating stroke than anything weve synthesized
"But that's not really a honest answer of how I feel
"My feeling is that vampire bats are inherently valuable
"I seem to vaguely recall thinking that vampire bats were ugly
"but now their faces just look like a person's face to me."
He says they behave like people.
When one bat is starving, another one comes to feed it
They wrap each other in these weird hugs - mothers and daughters, brothers and sisters,
and even bats who aren't related to each other, but have what scientists call
"enduring cooperative social bonds"
in other words
FRIENDS
It's those friendships that make that poison spread so quickly through a colony
The bats love to cuddle.
And that makes this question about what to do with them really difficult.
The way that I think of it is sort of analogous to how we relate to wolves now
Wolves were a problem for farmers and ranchers just like vampire bats
and for long stretches of time people just wanted to eradicate wolves
But now we see wolves as these beautiful, charismatic, intelligent animals that we can relate to
I don't think we have that kind of relationship with vampire bats
But I think if people new all the things that I know about vampire bats
You would look at them differently -
As beautiful intelligent animals