Tortoises to Go on ‘Threatened’ List : Environment: The U.S. government action will free funds for research and protection of the desert species. Builders and off-road enthusiasts face new curbs.

The U.S. Fish and Wildlife Service, concerned that the lumbering desert tortoise may be inching toward extinction, plans to add the Mojave Desert population of the reptile to the nation’s list of threatened species, it was announced Wednesday.

In a prepared statement, Secretary of the Interior Manuel Lujan Jr. called the tortoise “a symbol of the desert Southwest” and pledged to “make every feasible effort” to save the species.

The action, which makes permanent an earlier emergency ruling, will free up funds for scientific research and protection of the tortoise and is expected to spark further restrictions on new housing construction, off-road vehicle racing, sheep and cattle grazing and even military maneuvers in the desert.

While the listing as threatened falls short of the “endangered” status wildlife organizations have sought for the tortoise, spokesmen for those groups nonetheless predicted the move would help reverse the critter’s decline.

Indeed, they conceded that the protections afforded to an endangered species--defined as one on the verge of extinction--differ little from those granted a threatened species, one viewed as likely to become endangered in the near future.

“The significance of the listing is in its recognition that this species is in trouble,” said Michael Bean of the Environmental Defense Fund, one of three groups that have pressed for federal protection of the tortoise since 1984. “The tortoise is merely one indication that the entire Mojave Desert is under tremendous stress.”

Environmentalists were disappointed, however, that the listing excluded tortoises in the Sonoran Desert of Arizona. That population is separated from the Mojave Desert animals by the Colorado River, and federal officials said they lack sufficient data to determine whether the Sonoran tortoises merit similar protection.

Opponents of the listing called it a premature step that would severely restrict commercial and recreational use of the desert.

“We question their data and we question the reasoning behind this,” said Dana Bell, a district official for the American Motorcyclists Assn. “This animal has been hurt by drought, and its population has changed. But no, I don’t believe it’s threatened.”

The tortoise, the official state reptile of California and Nevada, can live for 50 years and grows a shell up to 12 inches long. Once abundant in the deserts of California, Nevada, Utah and Arizona, the reptile has declined at a rate of 10% or more annually in the west Mojave in recent years. An estimated 60,000 tortoises remain in California.

Sheep and cattle that graze in the desert reduce the native plants upon which tortoises feed, and off-road vehicles crush the slow-moving animals or collapse their burrows.

Theft and vandalism are other enemies. A study of tortoise carcasses in the west Mojave found more than 14% had suffered gunshot wounds.

Over the last decade, a new threat that appears to have hastened the tortoise’s decline has emerged--a respiratory disease. Usually fatal, the mysterious disease has been seen for years in captive tortoises but now is infecting wild animals at an alarming rate.

Last June, the state Fish and Game Commission added the tortoise to California’s list of threatened species.

In August, the tortoise was designated an endangered species by the Fish and Wildlife Service under an emergency measure providing protections for eight months.

Under the Endangered Species Act, it is illegal to take, harm or kill a threatened species without a special federal permit. Consequently, owners of land occupied by a threatened species may not build without such permits, which typically require an elaborate plan for protection of the animals or compensation for any lost habitat.

Federal agencies also are bound by the listing; they must consult with Fish and Wildlife biologists on any project affecting an endangered species.

Immediately after the emergency listing, both private parties and government agencies began to feel its effect. The Army, for example, has seen its expansion plan at Ft. Irwin, near Barstow, stalled because the territory targeted for acquisition is home to tortoises.

Nevada developers also have felt the brunt of the tortoise’s new status. “It has hit us hard,” said Terry Murphy of the Southern Nevada Homebuilders Assn., which sued the federal government after the emergency listing and since has reached a tentative settlement that will permit development of 7,000 acres of habitat surrounding Las Vegas.