Wilderness Sierra Bighorn Sheep Research

Yosemite National Park » Wilderness Sierra Bighorn Sheep Research » Document List

California Department of Fish and Game (CDFG)will be conducting capture from helicopter of bighorn sheep that range mostly outside of the park, but need approval to fly over the park if bighorns being pursued move into the park, or if target animals can only be found in the park. Capture of bighorns would be done by firing a net gun from the helicopter, then dropping off personnel to collect data on the captured animal, and attach a radio collar. This method has been widely used, and has resulted in little risk to the bighorns. Currently, the range of the herd barely extends into Yosemite along the east boundary north and south of Tioga Road (see attached map). The capture of sheep, given their current distribution is unlikely, but CDFG needs the flexibility to find and capture bighorns in the park, if that situation arises. The bighorns in this herd are the ones most likely to repopulate Yosemite habitats, and needs intensive monitoring to detect problems in survival and reproduction in this relatively small population. This data is critical to facilitating the growth of this population. In 1985, the Park Service took an active role in the reintroduction of this population; they are an active member of the Sierra Nevada Bighorn Sheep Recovery Team and the SNBS Stakeholders group. As such, the park should do what it can to enable adequate data collection and monitoring of this endangered species. Periodic capture operations would be conducted from early November to late April; a period when there is little use of wilderness by visitors, so disturbance of solitude would be unlikely.