Desert Bighorns on the Rise
Nearly a century ago, wildlife biologists estimated there were about 500 desert bighorn sheep in Texas. About fifty years later, there were none. Today there are 500 of these majestic animals in the state once again.
Texas Parks and Wildlife biologists recently completed their annual desert bighorn sheep counts and report populations have finally reached a satisfactory level after years of restoration efforts.
"I honestly believe we're at 1905 numbers, when the original biological survey was conducted in Texas," said Clay Brewer, bighorn program leader for TPW. "It's been a slow process, but we're making some great strides."
The desert bighorn sheep was once prominent in the remote mountains of West Texas, with populations of more than 1,500 animals in the late 1800s. Due largely to unregulated hunting, bighorn numbers dwindled to about 500, according to the survey conducted by Vernon Bailey.
Protective measures for bighorn sheep began as early as 1903 with the enactment of a hunting prohibition; however, changing land use caused numbers to decline to an estimated 35 sheep by 1945. The last reported sighting of a native bighorn sheep occurred in October 1958 on the Sierra Diablo Wildlife Management Area. Biologists believe the last native Texas bighorns were gone by the early 1960s.
Efforts to restore bighorns in Texas began in 1954 with the development of a cooperative agreement among state and federal wildlife agencies and private conservation groups. Since then, 410 bighorn sheep have been relocated to seven mountain ranges in Texas. Of these, 146 sheep were moved from other states and Mexico. In addition, 264 in-state desert bighorns were relocated between 1971 and 1997.
Through landowner and Texas Bighorn Society support, remote mountains in the Trans Pecos have been enhanced to meet the basic needs of the desert bighorn, including construction of 36 man-made water guzzlers. These capture the area's limited rainfall to provide year-round water sources for sheep and other wildlife.
The Texas Bighorn Society recently installed a satellite Web camera and a weather monitoring system near one of these "drinkers" atop Elephant Mountain and is downloading images and data three times daily to its Web site (here). "This setup gives us the opportunity to show people what's out there," explains the society's David Wetzel. "The odds of most people ever seeing a bighorn in the wild are pretty slim. Beyond that, we think there's some really valid biological information that can be gathered."
Because bighorn sheep habitat resources are limited, biologists are exploring options that could allow these animals to get the most out of what's available. Reopening travel corridors closed off to sheep for decades by ranchers who manage livestock is one such prospect.
A fence manipulation test project, funded through a grant from the National Fish and Wildlife Foundation, in cooperation with private landowners, TPW, Parks and Wildlife Foundation of Texas Inc. and the Texas Bighorn Society, is scheduled to begin in January in the Sierra Diablo Mountains.
"The rims along the Sierra Diablo run north and south and the fences run perpendicular, which creates a barrier that sheep will not cross," says Brewer. "Fences restrict the potential for movement between available resources; sheep can get around them, but they may have to come down out of escape cover to do so.
"Some of those fences have been there since the '30s and are in some really remote places," he said. "We've got landowners willing to help where it's compatible with their land use practices. We'll be raising the bottom strand on these fences high enough off the ground that sheep can go underneath."
If the project is successful, Brewer adds, it could become a model for wildlife management on a larger scale -- possibly helping in the recovery of pronghorn antelope, too.
In addition to the Sierra Diablo project, hunter funded initiatives such as the Big Time Texas Hunts and the Sport Fish and Wildlife Restoration federal aid program have provided money for ongoing TPW research and management efforts. One such project is a radio telemetry tracking study that is allowing biologists to follow sheep at Elephant Mountain and Black Gap Wildlife Management Areas.
In December 2000, helicopter capture crews located and trapped the elusive bighorn sheep along the rims and canyons that make up the Elephant Mountain WMA. Wildlife biologists fitted the sheep with radio tracking collars and transplanted the captured animals to suitable sheep habitat two hours away at the Black Gap WMA. Black Gap is located adjacent to the Rio Grande River just northeast of Big Bend National Park.
Information from these projects will help researchers identify future stocking sites and enhance the prospects of a healthy future for bighorns in Texas.