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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.
ENDANGERED SPECIES ACT PROFILE
PROTECTION STATUS: Endangered
YEAR PLACED ON LIST: 1999 (emergency rule); 2000 (final rule)
CRITICAL HABITAT: None currently; proposed critical habitat and taxonomic revision 2007
RECOVERY PLAN: 2008
RANGE: High-elevation areas on the eastern side of the Sierra Nevada mountains, including parts of Yosemite National Park, Sequoia National Park, Lee Vining Canyon, Wheeler Crest, Mount Baxter, Mount Williamson, and Mount Langley in Mono and Inyo counties, California
THREATS: Diseases spread by domestic sheep, predation, small population size, competition for forage, watershed degradation, poorly planned human recreation, and some development
POPULATION TREND: After increasing from 250 in 1978 to almost 300 in 1985, the total number of bighorn sheep in the Sierra Nevada declined by about 60 percent to just more than 100 in 1995. Since emergency listing in 1999, numbers have since increased; today there are more than 300 individuals.
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SAVING THE SIERRA NEVADA BIGHORN SHEEP
The Sierra Nevada bighorn sheep was the first species to be listed under the Endangered Species Act in the 21 st century, and rightly so: in fact, listing should have happened much sooner. 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 few 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 20 th 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. Three subpopulations have been reintroduced to areas where they were lost, and the U.S. Forest Service has taken measures to reduce the impact of domestic sheep on bighorn populations. In 2008, eight years after listing, a recovery plan for the species was finally published. But although the Endangered Species Act requires critical habitat to be designated at the time of listing, the U.S. Fish and Wildlife Service has been slow to put concrete federal habitat protections in place. In 2005, the Center sued the Service to force critical habitat designation, and in 2007, the Service proposed designating a total of 417,577 acres. A final decision is due in the summer of 2008.
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Contacts: Chris Kassar, Lisa Belenky
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