The vanishing bighorn
On a clear, pine-scented summer night, two wildlife biologists and a pair of volunteers bang and bounce down a steep, rocky road, dragging from the pickup’s bumper a big conveyor belt-like flap (think carwash).
Working for hours by headlights on a 26-mile route through the Sheep Mountain Wilderness, they comb the terrain, laying the groundwork for one phase in a long-term investigation. What’s killing the bighorn sheep in L.A.’s backyard? High on the list of suspected predators: bobcats, coyotes, feral and stray dogs and mountain lions.
A target of research in the San Gabriel Mountains for decades, the bighorn sheep has plummeted in number, from 740 in 1980 to just 60 at last count. Biologists also blame the loss of open, or “escape,” habitat on the rugged slopes. Although they are keen-sighted and expert rock climbers, naturally equipped with spongy footpads, Nelson bighorn sheep cannot escape what they cannot see lurking in thick brush.
Part of the study involves capturing and radio-collaring, at a cost of $12,000 each, from 25 to 40 sheep to track their movements and mortality, as well as collaring mountain lions. Solitary animals, the cats can range up to 100 miles.
“We are collaring the cougars so that we don’t have to kill them,” said Steve Torres, a senior biologist for the California Department of Fish and Game, which is heading the $4.9-million restoration study. “But we will take all steps necessary to save the severely threatened bighorn sheep.”
On the morning after the “drag,” department wildlife biologists Rebecca Barboza and Chanelle Davis tie on bandannas to cover their mouths and pull on helmets. Hopping astride ATVs, they buzz along the edge of the road, retracing the pickup’s route into the backcountry behind Mt. Baldy. Here and there, fresh tracks dot the dirt. Fox. Deer. Coyote. But no signs of either bighorn or mountain lion.
Determining which species share habitat is key to understanding why deer flourish, for example, while sheep struggle to survive.
A few months after cataloging the animal tracks, Davis takes another ride, this time in a helicopter over the Cucamonga Wilderness, an area adjacent to the Sheep Mountain Wilderness that was incinerated in the recent wildfires. Wildlife officials had planned to do controlled burns there to restore open habitat for the bighorn. Now it may not have to.
“They’re all there!” Davis cheered as she picked up the last of six signals of radio-collared sheep in the area. All had survived the inferno. And Torres is confident the species will thrive again if the habitat completes rehab.
The restoration program needs volunteers to assist with such tasks as examining dirt roads and hiking trails for tracks. Biologists offer training in detecting tracks and other signs of deer, bighorn and mountain lion. To enroll as a volunteer or report bighorn sightings in the San Gabriel Mountains, go to www.NelsonBighorn.com.
