nowledge there is no proof that cattle grazing has direct impacts on the health or well-being of desert tortoises, according to Mr. Slone. To help find out, a new 220-acre research center has been established outside town here to study the basic biological requirements of desert tortoises.
The center was established in a negotiated settlement with developers in 1990. The developers had sued the BLM in 1990 after the tortoise's listing halted construction in several major expansion projects.
A 400,000-acre tortoise preserve was also established on BLM lands that year through a short-term habitat-conservation plan with Clark County, Las Vegas, and the city of Henderson. The purpose is to set aside public lands for tortoises in exchange for the continued development of the Las Vegas valley. Cattle affect habitat
"In five years, we will better be able to demonstrate the effects [on tortoises] of grazing," says Slone. Besides eating plants that tortoises need, cattle trample the soil, affecting its ability to hold moisture for vegetation. They also impact the burrowing habits of tortoises, who sleep underground eight months of the year.
Beyond that, conservationists call tortoises an "indicator" species, holding that if the animal is having a hard time surviving for some reason, other animals are as well. "It may be there will be no effect, and we can all go back to business as usual," says Slone.
But ranchers say they cannot pick up the pieces after a half decade and start again. "I will go belly up," says Kelly Jensen, whose family has ranched here for three generations. Because desert conditions are far rougher than range, prairie, or farm conditions, calves must spend time learning survival in the environment from their mothers. "You just can't take any old cattle and put them in the desert and expect them to survive," says rancher Jensen.
Part of the dispute between ranchers and BLM officials concerns the reasons for dwindling tortoise populations in the West.
Having shown that tortoise populations have dropped 90 percent in the last 50 years - and in some areas of the Mojave declining 50 percent in seven years - environmentalists were able to get the tortoise emergency status on the federal list of endangered species in 1989. The emergency listing became permanent on April 2, 1990.
Estimates were once as high as 1,000 tortoises per square mile in certain areas. Environmentalists hold that only 60,000 remain while opponents say the number may be as high as 1 million.
Several organizations hold that the dramatic losses in tortoises are due to a respiratory disease, exacerbated in part by the release of captive tortoises into the wild. Growing coalitions of so-called "wise-users miners, ranchers, bikers, and off-road vehicle users - oppose the move as a bureaucratic smokescreen to prohibit legitimate use of public lands.
"This action is unfair and not founded on scientific evidence," says Mr. Connelley. He says studies have shown that the tortoise numbers reached their height in the 1960s when livestock numbers were at their height because tortoises thrive on cow manure. Users of public land in Western states have been buffeted in recent years by legislation introduced by US Rep. Michael Synar (D) of Oklahoma to charge grazing rates on federal lands commensurate with that by private lessees.
"This is one more attempt to turn the planet into a national park," Connelley says. "If we keep putting restrictions on our ability to produce, we are going to find ourselves more and more dependent on foreign sources." Some compromise
Slone says the BLM is trying to negotiate with some ranchers to help them shift grazing patterns to parcels where the tortoise is not so threatened. Of approximately 7,800 cattle affected in the decision, less than 1,000 have no other grazing alternatives, he says. Several ranchers have been granted one-year grace periods.
And the BLM has already been criticized by some environmental groups for not going far enough, soon enough. "We are trying to reduce the impact on tortoises in such a way as to minimiz