Bighorns Being Fenced Out to Save Their Lives

The largest herd of bighorn sheep in the Rancho Mirage desert highlands may perch not above some rocky point but on the city’s supply of stationery, which features a stylized ram.

Chosen by Rancho Mirage as its official symbol nearly three decades ago, the bighorn’s fortunes have faltered as the city’s population swelled.

Struck by cars, drowned in swimming pools, poisoned by pesticides and exotic plants, the animal’s plight puts it on the federal endangered species list. In an effort to save the remaining herd from further harm, city officials are building a 3 1/2-mile, $1.2-million fence to separate the sheep from civilization.

“The one way to keep this from hurting the sheep, short of the federal government coming in and telling us we can’t develop . . . vacant land, is to build a barrier that will take care of the problem,” said Patrick Pratt, Rancho Mirage’s city manager.

That barrier, an 8-foot-high mesh fence, will border the flatlands along California 111 and scale the Santa Rosa Mountains’ steep peaks. It will measure about 3 1/2 miles as the crow flies, but about eight to 10 miles as the sheep scrambles. An initial stretch, built in 1999, proved to be inadequate after the sheep learned they could skirt the barrier by walking to its end.

Work on the second phase, which reaches from the western city limits to a flood-control channel in the east, began in December and is expected to take about four months. The city is paying about $880,000 of the cost; private donations total more than $300,000.

A third phase will be built partly by a developer who is required to erect the fence by an agreement with the city that provides building rights in exchange.

“We’ve had letters to the editor in the local paper and comments during City Council meetings questioning our commitment to this fence,” Pratt said. “But that’s the way of the world. Not everyone agrees on everything.”

Local and federal wildlife experts do agree on the need to help the region’s sheep. About 1,200 bighorn roamed the Peninsular range, which includes the Santa Rosa and San Jacinto mountains, in 1973 when Rancho Mirage incorporated. By the mid-1990s, the number had plummeted to 276 before rebounding a bit to 400 sheep today.

Two local herds--the Santa Rosa population, which numbers 45, and the San Jacinto population, which includes 29, have continued to lose ground as development has closed in on the foothills and mountains. Because ewes produce just one lamb a year, the species’ well-being depends on the herds’ success in rearing their young.

“We began a lamb mortality study that showed us most of the deaths were taking place in the urban areas,” said Jim DeForge, founder and director of the Bighorn Institute in Palm Desert. “It became clear that we would have to separate the sheep from the developed areas if they were to survive.”

Bighorn sheep became established in North America after crossing the Bering land bridge from Eurasia during the late Pleistocene Epoch, according to the U.S. Environmental Protection Agency. Sheep in the Peninsular range roam from the San Jacinto Mountains near Palm Springs and the Santa Rosas near Rancho Mirage to the Volcan Tres Virgenes Mountains near Santa Rosalia, in Mexico’s Baja California.

They prefer altitudes ranging from 300 to 4,000 feet, where annual rainfall seldom tops 4 inches and temperatures climb to 104 degrees.

In 1971, the California Fish and Game Commission listed the species as “rare.” In March 1998, the sheep were placed on the endangered species list. By building the bighorn fence, biologists say, Rancho Mirage is taking an important step in protecting them.

“This fence will remove one of the greatest sources of mortality to the sheep,” said Kevin Brennan, a wildlife biologist with the state Department of Fish and Game. “The lawns and landscaping of the city are attractive to the sheep, but they also can be fatal.”

One of the biggest lures--lush lawns--has been deadly. Sheep can ingest a parasite in the grass that, if it doesn’t kill them, can weaken them so much that they become vulnerable to predators, Brennan said. Simply wandering among buildings and shrubbery can make them an easy target for the bobcats and mountain lions that hunt in the Santa Rosa foothills.

Scientists say the sheep, whose grazing keeps growth down and helps spread native plants via seeds that get caught in their long coats, are an integral part of the mountain ecosystem. Rancho Mirage officials believe it is their duty to help save their city emblem.

“We are lucky enough to have the funds to do this,” Pratt said. “Our city founders saw fit to make the bighorn a symbol of the city, and it would seem odd for us to turn our backs on them.”