Experts work to re-establish bighorn sheep population in Big Bend
New observation deck to open at Big Bend Ranch State Park this spring.
Five years after 49 bighorn sheep burst from trailers and charged up scrub-covered hillsides at Big Bend Ranch State Park, experts say their population is holding steady, despite challenges from drought, predators and unfamiliar terrain.
Desert bighorn sheep, with their thick, gnarled gray horns, once roamed the rugged mountains of northern Mexico and Far West Texas. Unregulated hunting and disease carried by domestic and exotic livestock obliterated their numbers. By 1960, they were gone.
Conservation groups and private ranch owners have worked for decades to bring them back. Wildlife experts consider them a flagship species, helping to drive cross-border wildlife conservation efforts, as well as an indication of the area’s environmental health.
“I firmly believe they belong out here,” said biologist Froylán Hernández, head of the Texas Parks and Wildlife Department’s Desert Bighorn Sheep Program in Alpine. “They formed part of the ecological niche, and there was a void once they were gone. They need to be back here to be part of a functioning ecosystem.”
Bighorn sheep like steep, rocky slopes with minimal vegetation; that’s why Big Bend Ranch State Park, which is crisscrossed with rugged canyons and bristles with cactus, was chosen as a release site. Biologists hope the animals here will intermingle with other groups in northern Mexico, creating genetic diversity and more robust herds.
The repopulation effort hasn’t been easy. Bighorn sheep must compete with non-native species such as burros and aoudads, or Barbary sheep, an African import, for resources such as food and water. Aoudads carry diseases that threaten the bighorn. Bighorn sheep are also a favorite meal of the area’s mountain lions.
In all, 209 bighorn have been released at the park since 2010.
The first batch came from Elephant Mountain Wildlife Management Area near Alpine. Trappers in a helicopters used net guns to capture animals on the run. Blindfolded and hobbled, the animals rode in mesh slings to a staging area, where veterinarians and wildlife biologists checked their health and fitted them with radio-tracking collars. From there, they rode by truck to the state park.
“Obviously every animal we release we’d like to see again, but that’s not always the case,” Hernández said. “We expect some losses, and initially those losses were pretty heavy.”
The relocations took place at the height of a yearslong drought. Predators killed some of the bighorn. Others ventured 30 or 40 miles away, crossing into Mexico. Some returned; others recolonized in new areas.
But recent surveys show the population may be taking root. Researchers observed 56 bighorn at the park in a 2013 survey and 51 a year later. In 2015, though, they counted 95. They know even more bighorn roam the mountains, because the radio tracking collars that a few of the animals still wear show them zigzagging through the desert.
“We probably only see 60 percent of animals that are out there,” said Hernández, who says the park and surrounding mountains can support a population of about 300 bighorn.
Some of the animals now living at the park came from the original release, but the group is growing naturally, too. In 2013 and 2014, more than 70 percent of the female sheep produced lambs. That number dropped to about 50 percent in 2015, but for bighorn sheep in the wild, that’s still a good number.
“The last three years have been very productive,” Hernández said. “That’s kind of what we expected — for those numbers to gradually start to increase.”
The relocation effort costs about $1,000 per animal, and is funded mainly through donations to the Texas Bighorn Society and other nonprofit organizations, along with sales of bighorn sheep hunting permits. The permits typically sell for $70,000 or more, leading some to criticize the sport as exclusively for the rich. Texas Parks and Wildlife also conducts a drawing for a single permit each year; entry into that lottery costs $10.
Public hunting of the sheep might eventually take place in Big Bend Ranch State Park, but parks and wildlife officials say that’s not the primary goal of the restoration project.
Now that the sheep are settling in, park officials hope to lure another species — animal-loving human tourists wanting to catch a glimpse of the herd. In April, crews will build an observation deck, complete with a telescope, to make that a little easier. The observation deck will go in at the top of a mesa, near a new “guzzler,” a man-made water collection device where the animals can drink. A few dry camping sites for RVs will be located nearby.
“They are such beautiful, majestic animals, and the park is a great place for people to be able to see them,” said Kathy Boone, director of the Texas Bighorn Society, which contributed about $10,000 in private donations to build the platform, which will be located on parkland along RM 170 about 20 miles west of Lajitas. If it proves popular, they’ll add interpretive signage.
Still, it’ll take some luck for park visitors to catch a glimpse of the wily bighorns.
“They move very early in morning and are pretty skittish,” says Nathan Gold, complex superintendent of Big Bend Ranch State Park, Fort Leaton State Historic Site and Barton Warnock Visitor Center.
Gold hopes visitors lucky enough to see a bighorn will realize the species belongs here.
“What we do is try to restore the landscape and flora and fauna to what it was naturally,” he said. “It’s just the right thing to do for Texans and future generations, so they can understand the land as it’s supposed to be.”
About desert bighorn sheep