NARRATOR: Texas is home to some amazing bats.
There are more than 30 species here.
[bats calling]
While different and unique,
these flying mammals face all kinds of threats.
[traffic rumbles]
- NATE: We're at the McNeil Bridge in Round Rock,
this is an I-35 bridge north of Austin.
[somber music]
This is one of the largest urban bat colonies in the state.
NARRATOR: A winter storm has hit this
Mexican free-tailed bat colony especially hard
and biologist, Nate Fuller is here to see how they're doing.
- We're trying to understand
what the impact of the cold storm was.
I wouldn't hesitate to say that there are
probably 10,000 dead bats in the area
of this entire bridge.
[somber music]
Are you okay?
Oh, you poor thing.
Some of the early migrants have come back
because we've had such a warm winter
and this cold event caught them off guard.
[somber music]
They can't go out and forage,
these bats are probably rather dehydrated,
they're definitely starving
and so we think what's happening here,
we've got a pretty big die-off
related to a lack of food and water,
rather than direct effects of the freeze.
[somber music]
NARRATOR: Nate's job is to keep an eye
on the bat populations around the state.
In East Texas, inside some culverts,
the rare tri-colored bat faces another challenge.
Biologists are worried about a deadly fungal disease
called White Nose Syndrome.
- White Nose Syndrome is all over North America right now
and it is knocking on the door
of lots of sensitive bat populations in Texas.
If the fungus gets here to these sites in East Texas,
we expect that the populations of tri-color bats
will be wiped out by the disease.
NARRATOR: To fight the fungus,
they came up with a fungicide-spraying --
- Here you go.
NARRATOR: Culvert-crawling contraction.
- Push the wheels out.
- And I can turn it on,
and turn it back off.
So we have a custom-built remote control
that allows us to remotely turn on and off
our dispersal device,
which we're gonna push into the culvert
and we're gonna turn on remotely
which will then disperse the chemicals
that should kill the fungus
or at least suppress it from growing.
- So we spent a lot of time trying to figure out
how to make this work.
We had early ideas
of running tubing down the culvert with vents on it
so it would spray the whole way
and couldn't figure out how that would work
and we had all kinds of crazy ideas
and finally we came on this idea of a cart
and it seems to work pretty well.
[cart rattling]
- This is a species that's one of the hardest hit
by White Nose Syndrome.
Within two years of the White Nose fungus
entering a culvert or a cave system,
you can see up to a 99% decline in the population.
[cart rattling]
- NATE: So the goal here is to protect
these very sensitive species of bat from the disease
before it gets here.
[tarp flapping]
[dramatic music]
[water dripping]
- KYLE: So what we're attempting here
is a type of fumigation.
This method we developed is a way
that we can treat all of the bats at once.
We can keep the bats where they are inside of the culvert
and we can disperse these chemicals in the air
so we can treat at the colony level.
[machine whirring]
It's looking good.
Two minutes, 20 seconds left.
- NATE: The compound that we're spraying inside this roost
doesn't affect the bats at all.
It is strictly a fungicide.
It kills the fungus and it prevents the
fungus from growing.
The bats are fine.
The bats will survive this treatment just fine.
The fungus will not
and thus won't cause White Nose Syndrome in the future.
[tarp flapping]
- JONAH: The plan right now is to slow down the impact
of the disease
and give the bats some time to pass around resistance
or some sort of tolerance to the fungus.
- Our hope is that by keeping these populations healthy,
we can provide a remnant population
that will be protected from White Nose Syndrome
for years to come
and maybe at some point, be the source of re-population
for the rest of the region.
NARRATOR: There's also a glimmer of hope
back underneath that bridge.
- Come on,
come on.
These guys went through a challenge,
but it looks like a good number of them made it through.
[dramatic music]
I really think that, you know,
most of the population is still down south,
so I'm hoping that when those come back,
this is gonna be a big, vibrant colony again.
[dramatic music]
♪ ♪