For the first time in a century, endangered Sierra Nevada bighorn sheep are back on their ancestral range and headed toward recovery. Prior to the arrival of western settlers, which brought unregulated hunting and diseases in their livestock, bighorn sheep populations likely numbered in the thousands.
During an ongoing relocation effort, dozens of bighorns have been captured with nets dropped from helicopters then moved to Yosemite and Sequoia national parks. In the last week of March 2015, nine ewes (females) and three rams (males) were moved from the Inyo National Forest and Sequoia National Park to the Cathedral Range in Yosemite National Park. In addition, seven ewes were moved to the Laurel Creek area of Sequoia National Park;the CDFW will attempt to move an additional three rams to that area on March 30.
“We’ve got the sheep where we want them on a broad geographic basis, which is a huge milestone,” California Department of Fish and Wildlife biologist Tom Stephenson told The Capitol Press. “We’ve still got to get their numbers up a bit.”
Between 1914 and 1986, no bighorn roamed Yosemite. The Sierra Nevada bighorn sheep is the only federally endangered mammal in Yosemite, Sequoia, and Kings Canyon. This animal was listed in 2000 after the population plunged to a low of about 100 individuals. The population has since increased to over 600, which marks an important milestone towards their recovery.
This latest chapter in the multi-year recovery effort involved the capture of Sierra Nevada bighorn sheep in wilderness areas on these federally managed lands. CDFW staff and volunteers, as well as veterinarians, biologists, and staff from other agencies, assessed the health and safety of the animals throughout the entire process. Each animal was fitted with a radio collar and a Global Positioning System (GPS) collar in order to track its movements over the next several years.
The newly released bighorn sheep are expected to thrive in their new homes because both of these historically occupied areas have superb summer habitat with adequate forage, are close enough to other Sierra Nevada bighorn sheep to provide the potential for connectivity among herds, and are far enough from most domestic sheep grazing areas to provide a buffer from potential disease transmission.