Critical Habitat Finalized for Sierra Nevada Bighorn Sheep Changes in Domestic Sheep Grazing Needed to Preserve Habitat and Save Bighorn From Extinction Published on Aug 5, 2008 - 9:34:45 AM
San Francisco, Aug. 5, 2008 - Responding to a lawsuit brought by the Center for Biological Diversity, the U.S. Fish and Wildlife Service today finalized critical habitat for the Sierra Nevada bighorn sheep, including more than 400,000 acres of land deemed essential for the sheep's survival and recovery in the eastern Sierra Nevada.
The endangered Sierra Nevada bighorn sheep (Ovis canadensis sierrae) is one of the most magnificent species in the Sierra Nevada. Bighorn are found on steep eastern slopes and high alpine meadows from north of Yosemite National Park through the mountains to south of Sequoia and Kings Canyon national parks. Even though the Sierra Nevada bighorn's habitat is primarily on federal land and is relatively undisturbed, the species' distribution has been greatly reduced and fragmented over the past 150 years, leaving it vulnerable to extinction.
"This is a step in the right direction for the recovery of the Sierra Nevada bighorn sheep," said Chris Kassar, a wildlife biologist with the Center for Biological Diversity. "The bighorn is a majestic creature threatened by extinction. It desperately needs the safety net that critical habitat provides - especially in light of growing threats to its survival, including climate change, domestic sheep grazing, and damage from off-road vehicles."
Critical habitat designation is vital to endangered species recovery. Species with critical habitat are more than twice as likely to have an improving population trend than species without designated critical habitat. In spite of more than 20 years of conservation efforts by the state of California, the National Park Service, and others, the bighorn continued to decline until Endangered Species Act protections were secured through an emergency listing in 1999. At that time there were as few as 125 adult bighorn remaining in the Sierra Nevada; today there are an estimated 350 to 400.
Though this recovery trend demonstrates that the Endangered Species Act works, significant threats remain. Disease spread from domestic sheep continues to threaten the survival of Sierra Nevada bighorn. The California Department of Fish and Game recently suggested that at least one bighorn died in 2008 from pneumonia that was likely transmitted by domestic sheep, which foul watersheds and compete for food plants, compromising bighorn diets. Poorly managed recreation, especially off-road vehicle use, also threatens the bighorn.
"With critical habitat in place, the Fish and Wildlife Service and Forest Service must now address these remaining threats," said Kassar. "This designation places a clear mandate for the government to protect these lands for the recovery of the bighorn."
The recovery plan, adopted in 2007, notes that long-term survival and recovery will require eliminating the risk of disease transmission by removing domestic sheep from critical habitat and adjacent areas. Recovery may also require limiting recreational off-road vehicles, including snowmobiles, in critical habitat.
Background on the Sierra Nevada Bighorn Sheep
The majestic Sierra Nevada bighorn sheep is the eastern Sierra Nevada's only wild ovine mountaineer. Learning to leap from crag to crag in early lambhood, these bighorns develop quickly into keen-eyed, strong-limbed, and extremely agile creatures always on the move to escape mountain lions and find food among steep, rocky slopes. Although they once populated the High Sierra by the thousands, settlement of the West brought domestic sheep and other threats to the bighorn's habitat, and the species is thought to have been imperiled since the Gold Rush.
The Sierra Nevada bighorn sheep was the first species to be listed under the Endangered Species Act in the 21st century. The species began its decline as far back as the mid-1800s upon the influx of settlers and domestic sheep to the Sierra Nevada, and by 1995 the total population numbered hardly more than 100 individuals. Primarily because of diseases introduced by sheep grazing in their habitat, Sierra Nevada bighorns experienced a series of dramatic declines in the latter half of the 20th century. Thanks to Endangered Species Act listing, the bighorn has been brought back from the brink of extinction, and its population is slowly on the rise. In 2008, eight years after listing, a recovery plan for the species was finally published.
