California Department of Fish and Wildlife
Link to Yosemite Conservancy

Sierra Nevada Bighorn Sheep Yosemite Project

Since 2002, CDFW has radio-collared numerous bighorn sheep in the Mount Gibbs and Mount Warren (Yosemite) herd units, areas which include eastern portions of Yosemite National Park. Bighorn rams have repeatedly traveled long distances during this time. Bighorn captured east of Yosemite National Park are increasingly using areas within the Park. The first recent documentation of lambing within the Park occurred in 2006.

Technology has recently become available that allows for deployment of GPS collars on wildlife that enable real-time transmission of location data using the satellite phone network. Such collars have been and will continue to be deployed on bighorn in the Northern (Yosemite) Recovery Unit. Satellite collars offer tremendous improvements in the ability to monitor bighorn recovery. Movements of bighorn can be monitored on a daily basis. Acquiring remote locations will improve the efficiency of field observations to determine lambing success and the collection of forage and fecal samples that are analyzed to quantify nutritional status and genetics. GPS locations will be used to develop resource selection models that clarify suitable bighorn habitat within Yosemite National Park. Links to data acquired using GPS technology are found below. This project is being funded by the Yosemite Conservancy. Yosemite Pages where you can explore the project in more detail, including Google Earth video maps of bighorn sheep travel paths.

Maps

Based on our observations, bighorn habitat usage varies from year to year, as well as by season. Yosemite National Park is on the western edge of the primary range of bighorn from the Northern (Yosemite) Recovery Unit. You can see that most of the locations are east of the park. As the bighorn herd sizes grow, we anticipate increased usage of Yosemite Nationial Park. These maps of bighorn in general and of specific individuals may give you some insight as to where bighorn live and how they use the landscape. Archived maps from previous time periods can be accessed through links lower on the page.

Click to enlarge:

Explore S105 Movements with Google Earth ®

Archives of Past Maps Sierra Nevada Bighorn Sheep Yosemite Project