In the largest desert bighorn sheep relocation operation in Texas Parks and Wildlife history, 95 of the high country animals have been trapped this month in the mountains north of Van Horn and released some 190 miles away on Big Bend Ranch State Park.
Seventy-six ewes and 19 rams were captured by helicopter on several private ranches and a TPWD Wildlife Management Area, in the Beach, Sierra Diablo and Baylor mountain ranges of Culberson County and transported by trailer to the 300,000-acre state park in Presidio County.
The wildlife restoration operation began Dec. 12 at the civic center in Van Horn with a briefing for the 60 TPWD personnel and volunteers with the Texas Bighorn Society and Sul Ross University and continued through Dec. 17. The sheep were released about 20 miles west of Lajitas on FM 170, the river road, near Panther Canyon.
Last year, 46 bighorns (12 rams and 34 ewes) were captured by helicopter at Elephant Mountain Wildlife Management Area and moved to Big Bend Ranch State Park on Dec. 21-22, 2010. Of those sheep, the first to be introduced to the state park, more than 30 are known to be alive.
"If most sheep survive, we may now have close to a sustainable population on the state park," said Alpine-based Billy Tarrant, TPWD Wildlife Division district leader.
The restoration of bighorn sheep in Texas has been a conservation success story.
"Back in the 1800s, we believe the Trans-Pecos supported around 3,000 bighorn sheep," says Froylan Hernandez, TPWD's bighorn sheep program leader. "But by the 1960s, unregulated hunting and disease introduced through domestic sheep had made the bighorn extinct in Texas."
The last indigenous bighorn was sighted in the Sierra Diablo Mountains in October 1958, he said.
"Today, thanks to restocking that began more than 50 years ago, we estimate the herd has increased to half its historic size and half its historic range."
TPWD's goal is to get the Texas herd back to approximately 3,000, with colonies in most of the 16 mountain ranges with unoccupied critical habitat that sheep once inhabited. Bighorns can now be found in eight of those ranges, Hernandez said.
According to Hernandez, the removal of surplus sheep from the Baylor, Beach and Sierra Diablo Mountains will benefit the remaining herd in those three ranges, estimated at 800 animals, by reducing browsing pressure. In addition to supplementing the existing bighorn population in Big Bend Ranch State Park, the development of a robust herd in other areas also will allow future restocking efforts.
During the just-completed operation, TPWD used a private helicopter service to capture the sheep. When the pilot spotted a desirable sheep, a crew member used a gun that fired weighted nets to entangle the animal. Two "muggers" then jumped out of the low-hovering helicopter to blindfold and hobble the sheep, which was then placed a sling.
Once that was done, the helicopter took the sheep to a staging area where ground crews carried the animal to a check-in station where veterinarians took biological samples and wildlife biologists fitted some of the sheep with radio tracking collars. Then they were carefully loaded into trailers for the trip to Big Bend Ranch.
"Bighorn sheep are a flagship species," Hernandez said. "Managing them well benefits all other species which share their habitat."
On the Net:
More information: http://www.tpwd.state.tx.us/landwater/land/habitats/trans_pecos/big_game/desertbighornsheep/