The U.S. Fish and Wildlife Service has completed a cooperative plan to recover the Sierra Nevada bighorn sheep to a sustainable level, where it can be removed from the federally protected category.

"We strongly believe that a collaborative stewardship approach, involving government agencies and the private sector is critical to achieving the ultimate goal of recovery," said Steve Thompson, manager of the service's California-Nevada Operations Office.

The notice of the availability of the final recovery plan was published in today's Federal Register. A copy of the recovery plan and other information are available on the Internet at www.fws.gov/ventura/newsroom/ by a link within the body of the news release, or by contacting the Ventura Fish and Wildlife Office by telephone at 805-644-1766.

The Sierra Nevada bighorn sheep was listed as endangered on Jan. 3, 2000, following an emergency listing on April 20, 1999.

As such, it is at risk of extinction throughout all or a significant portion of its range. In 1999, only about 125 bighorn sheep remained in the Sierra Nevada, living in five separate areas on mountainous, federally-owned land primarily in California's Inyo and Mono counties. Their population has since increased to at least 400 individuals. Even though their habitat is primarily on federal land and is relatively undisturbed, their distribution has been greatly reduced and fragmented over the past 150 years, which leaves the sheep more vulnerable to extinction.

Sierra Nevada bighorn sheep are large animals that inhabit the east side and crest of the southern and central Sierra Nevada. They are sure-footed and agile with specialized hooves that enable them to easily negotiate steep, rocky terrain. The sheep breed in the fall, and the ewes give birth to one lamb in the spring or early summer.

Diseases spread by domestic sheep beginning in the 1860s coupled with indiscriminate hunting during that time period and possible predation by mountain lions in recent decades are considered the primary reasons for the decline of the bighorn sheep.

From February through April, the sheep may be more vulnerable to predators when they attempt to move to lower elevations to forage on new, nutritious plant growth and avoid harsh winter conditions

at higher elevation before lambs are born. During the 1980s bighorn sheep began remaining at higher elevations throughout the winter. This behavior led to greater risk of mortality due to exposure, avalanches, and an inadequate food supply, and was followed by a steep population decline.

Some believe that when the bighorn sheep herd size gets small, they will remain at higher elevations to avoid predation by mountain lions.

One of the recovery criteria outlined in the plan is to maintain specific population sizes for each recovery unit for seven consecutive years.

Another recovery criteria is to ensure that Sierra Nevada bighorn sheep of both sexes occupy at least two essential herd units in the Kern Recovery Unit, six in the Southern Recovery Unit, two in the Central Recovery Unit, and two in the Northern Recovery Unit. Currently, seven essential and one non-essential herd unit are occupied by Sierra Nevada bighorn sheep.

The rest of the units are currently not occupied by the Sierra Nevada bighorn sheep.