Weed-Eating Sheep Find a Home on the Range

The hills sloping down toward Lake Avery in the Oak Ridge State Wildlife Area outside this northwest Colorado hamlet are lushly carpeted this summer with western wheat grass, Idaho fescue and other native grasses.

These hillsides, which provide critically needed winter range for elk and deer, were not always so healthy. Just a few years ago, they were awash in leafy spurge, a noxious weed that made its way to America from Europe and has no natural predators on this side of the Atlantic.

Leafy spurge has now infested more than 3 million acres in the West--part of a broad invasion of western range land by nonnative weed species that is alarming land managers throughout the region and costing livestock producers tens of millions of dollars annually.

Isolated patches of spurge can still be found above Lake Avery. But by using sheep to intensively graze the infested portions of the 14,000-acre wildlife area in early summer, state officials have turned the tide against a stubborn, aggressive weed that sends roots 20 feet below the surface, can render pasture land nearly useless for cattle and horses and can devalue ranches to virtual worthlessness.

“We’ve contained it, and I believe we can eradicate it,” said Bob Griffin, a wildlife property technician with the state agency that manages Oak Ridge.

The victory at the Oak Ridge Wildlife Area is being repeated elsewhere in the West as ranchers and land managers discover they can use sheep, and in some cases goats, to control spurge and some other noxious plant invaders. Unlike cattle, which become ill if they eat spurge, sheep will, with a little encouragement, graze happily on it and thrive on its 20% protein content.

In a region where sheep are still reviled by cattlemen as despoilers of the public range and competitors for precious forage, there is considerable irony in the use of sheep to reclaim land for cattle.

“Some of these cow outfits wouldn’t have sheep on them no matter what,” observed sheep rancher John Paugh of Bozeman, Mont. “But there’s a market because there is no other economically sound way to control spurge. When you get large acreages of it, there is no other way available.”

Paugh, who runs about 2,200 lambs and ewes on spurge-infested range land near the Shields River in southwest Montana, said it is a good deal for him and for the cattle ranchers who rent him the land. He feeds his sheep for about half what it would cost to rent grass pasture, and his sheep are able to control the spurge for about one-third the $25 an acre cost of using herbicides.

For sheep ranchers, an economically beleaguered fraternity whose ranks have declined by 17% since 1993 because of pressure from cheaper imports, the loss of federal wool subsidies and other factors, a difference of a few cents per acre of forage can be critical.

Although both wool and lamb prices have rebounded recently, the 1990s have been tough for America’s sheep producers, according to Peter Orwick, executive director of the American Sheep Industry Assn. Average wool prices, which hit $1.40 per pound in the 1980s, went as low as 51 cents a pound three years ago, he said. And between 1991 and 1994, lamb meat sold for 50 cents a pound or less, compared with $1.50 today.

“On the lamb side, the biggest factor we face is imports,” Orwick said. “Imports have gone from 7% of consumption in 1993 to over 20% today.”

Pat Sturgeon, 57, a second-generation sheep rancher who for the past half-dozen years has contracted with the state of Colorado to graze his 900 head on the Oak Ridge Wildlife Area from late May to early July, has his own sheep-ranching economics index.

“In 1970, I could buy a new pickup with 100 lambs,” Sturgeon said as he showed off his flock to a visitor. “Now it takes 250 lambs. We don’t drive new pickups anymore.”

Being able to graze his sheep relatively cheaply on state land for 45 days early in the season before federal grazing allotments open up “gives us an advantage,” Sturgeon said. Under his contract with the state, he pays about $2 a month per head for grazing the wildlife area. That is several times higher than his cost later in the summer to graze on federal land, but it is still cheaper than what he would pay for private land.

“I need pasture in the spring,” he said. “It lines me up to get on my national forest permit later.”

Just how much of a dent sheep and goats can make in the leafy spurge problem is subject to considerable debate.

George Beck, a professor of weed science at Colorado State University who has been experimenting with sheep, both alone and in tandem with flea beetles on test plots outside Denver, said they are effective against spurge but not a silver bullet.

“It’s not the answer, because spurge is such a troublesome plant,” he said. “You’ll never get perfect control, but they are a valuable part of it.”

Don Smurthwaite, a Bureau of Land Management official in Boise, Idaho, is more enthusiastic. The federal agency this year imported 240 Angora goats from the Navajo Indian reservation in Arizona to help control spurge on 2,000 acres near Pocatello, and Smurthwaite said the experiment has “exceeded our wildest expectations.”

“It’s like inviting the high school football team to a pizza parlor,” he said. “They just demolished it.”