(wind)
(music)
[Narrator] Here in the Texas Hill Country, biologists
are keeping track of a Texas treasure.
[Jeff Forman] I stop in my tracks every time I hear one.
(bird sings)
[Jeff] There’s that bird right there.
Good looking little guy.
(bird sings)
[Narrator] The black-capped vireo, a migratory songbird,
is on the rise in these parts.
[Jeff] The species typically have a set of spectacles,
a little white eye-line.
The male has a distinct very tuxedo black cap on his head.
[Narrator] For a long time, the black-cap was considered
an endangered species.
But over the past 30 years this little bird has made a big comeback.
(bird sings)
[Narrator] Black-capped vireos winter on the Pacific
coast in Mexico, but every spring they migrate to parts of Texas to build nests and raise
their young.
(birds screeching)
[Jeff] Healthy nesting habitat is very much required
for the vireo’s sustainability.
[Narrator] Here at the Kerr Wildlife Management Area
in the Texas hill country, vireos can find plenty of prime nesting sites thanks to decades
of conservation work.
[Jeff] They really like these low shrubs with spaces
in between.
They can fly in and around and catch insects.
(boots crunching grass)
[Jeff] What great habitat!
This is typical hill country vireo nesting habitat.
They like a fork in the tree in a horizontal position similar to this.
They’ll start building their nest here out of spiderwebs.
(bird chirps)
[Narrator] Historically vireos thrived in the scattered
shrubs and open grassland that stretched across Central Texas.
But with European settlement, things changed.
[somber music]
[Jeff] What was happening here in the hill country,
cattle grazing…
(cow moos)
…sheep and goat production…
(goat bleats)
…sometimes the populations of those livestock weren’t kept in check.
They just ate the homes out from under the vireo.
(fire crackles)
[Narrator] The suppression of fire also prevented the
rejuvenation of low growing brush that they prefer for nesting.
And a booming deer population put more stress on the overgrazed landscape.
Habitat loss devastated vireo populations and in 1987 biologists put the vireo on the
endangered species list.
[Bill Armstrong] Well the vireo is important the same as deer
are important same as all these little animals are important because if they’re healthy,
then the land is healthy, and if the land is healthy we’re healthy.
And if the land isn’t healthy we’re not going to be healthy.
[Narrator] Wildlife biologist Bill Armstrong spent over
30 years on the Kerr.
He had a hand in the research that led to restoring healthy vireo nesting habitat in
the hill country.
(chainsaw buzzes)
[Bill Armstrong] We started a cedar-control program.
(fire crackles)
[Bill] We started fire to control that cedar.
We were beginning to experiment with what they call rotational grazing systems with
cattle.
(cows mooing)
[Bill] A rotational grazing system is nothing more
than an organized way to graze animals.
We also decided to reduce the deer herd by half.
(bird chirps)
[Bill] The key to what we were doing is we were beginning
to build the kinds of habitats that the bird liked.
(bird chirps)
[Bill] We started out with about 27 birds on the
area.
And as we began to build the kinds of habitat that the birds liked, we increased from 27
birds to well over 400 in about a ten-year period of time.
(bird chirps)
[Narrator] But vireos still faced another threat: the
brown-headed cowbird.
(bird twitters)
[Ryan Reitz] Brown-headed cowbirds are a native bird.
(bisons grunting)
[Ryan] Likely evolved with grazing bison.
Because they were on the move continually with grazing herds, they chose to lay their
eggs in other native songbird nests.
(bird twitters)
[Jeff] Every one of those birds was reared in a songbird
nest.
It’s parents don’t build nests.
It’s parents don’t raise their young.
Some other species cared for that little bird and probably neglected it’s own.
(Wings flapping)
[Narrator] In addition to land management, cowbird trapping
is also used to protect the vireo.
(Latch squeaks)
[Ryan] We time that during nesting season.
(Wings flapping)
[Ryan] We use live cowbirds.
They’re fed, they’re watered, they’re kept healthy and used to attract other cowbirds
into that trap.
[Ryan] The goal here is not to eliminate brown-headed
cowbirds on the landscape.
The goal is to reduce parasitism rates.
Reducing that level of parasitism rate is the key to increasing the abundance of black-capped
vireos.
(Birds chirping)
[Narrator] In 2018, all this hard work paid off.
(uplifting music)
[Ryan] Black-capped vireos were delisted April 2018.
The population reached a level of recovery.
Over 15,000 birds currently estimated of the ranges we survey birds.
(Bird sings)
[Jeff] We know they need continued protection.
In fact there’s a post-delisting monitoring plan we will all be a part of here.
[Jeff] It’s a treat to see something that’s endangered
or was endangered.
It’s made a comeback.
It’s special.
(Bird sings)
[Bill] To see something you started with getting
off on its own.
I think it’s great.
(Cicadas chirping)