March 13, 1998
PENINSULAR BIGHORN SHEEP PROTECTED UNDER THE ENDANGERED
The Peninsular bighorn sheep, a majestic and cherished symbol of the California desert wilderness, will be added to the list of Federally-protected endangered species, the U.S. Fish and Wildlife Service announced today. The animal has been protected by the California Endangered Species Act since 1971.
Peninsular bighorn sheep occur along the hot, dry desert mountain ranges from the San Jacinto Mountains near Palm Springs, California, to the Volcan Tres Virgenes Mountains, north of Santa Rosalia, Baja California, Mexico. The entire range of the Peninsular bighorn sheep extends along approximately 500 miles of contiguous habitat. Currently, only the United States population is considered endangered; the Mexican population is not included in this listing action.
The Peninsular bighorn sheep population in the U.S. has declined by at least 76 percent between 1971 and 1997, from 1,170 to only 280 individuals. The species no longer occurs in several historic locations, including the Fish Creek Mountains in Imperial County and the Sawtooth Range in San Diego County.
The California Department of Fish and Game has developed management plans for the sheep in the Santa Rosa Mountains and McCain Valley in eastern San Diego County, acquired 30,000 acres of habitat in the Santa Rosa Mountains, conducted research, and established three ecological reserves that protect important watering sites. The state and the Bighorn Institute are conducting captive breeding programs to augment the remaining population.
Habitat loss associated with residential and commercial development, roads, water projects, and recreational use have contributed to the decline of the bighorn throughout its range. Viral and bacterial diseases, often a sign of environmental stress, are contributing factors in the precipitous decline of this species.
Increased predation has also been documented closer to urban environments; the cause of this increase in unknown at this time. Higher numbers of adult sheep have been killed by mountain lions closer to urban areas as compared to wild lands. Domestic dogs, which are typically more abundant in urban areas, are capable of injuring and killing lambs, ewes, and young rams.
Several studies have shown that bighorn sheep respond to human presence, including roads and housing developments, by altering behavior patterns to avoid contact. This behavioral response may preclude or disrupt sheep use of vital water sources, mineral licks, feeding areas, and breeding sites.
The Bureau of Land Management and the U.S. Forest Service's San Bernardino National Forest manage lands that contain bighorn sheep habitat. These and other land management agencies, including city and county governments and a variety of interested groups, are cooperating in the preparation of a multi-species habitat conservation plan for the Coachella Valley that will help focus conservation actions on bighorn sheep.
The Endangered Species Act directs Federal agencies to protect and promote the recovery of listed species. Proposed Federal projects and actions, including activities on private or non-Federal lands that involve Federal funding or permitting, require review by the Fish and Wildlife Service to ensure they will not jeopardize the survival of listed species. Once a species is listed, all protective measures authorized by the Endangered Species Act apply to the species and its habitat.
The final rule listing the Peninsular bighorn sheep will be published in the Federal
Register on March 18, 1998. Requests for references and additional information
should be directed to the Field Supervisor, U.S. Fish and Wildlife Service, 2730 Loker
Avenue West, Carlsbad, California 92008, telephone 760/431-9440.
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