Interagency News Release
Grand Teton National Park
Wyoming Game and Fish
Bridger-Teton National Forest
December 11, 2007
Grand Teton National Park, Bridger-Teton National Forest, Caribou-Targhee National Forest, and the Wyoming Game and Fish Department will begin an interagency study of the Teton Range bighorn sheep population in cooperation with a graduate student from the Fish & Wildlife Coop Unit at the University of Wyoming. The Teton Range herd occupies high elevation habitat that spans across federal lands on both the park and forests. This study will provide valuable information for interagency partners about the health and future of the herd.
The agencies have contracted with wildlife capture professionals to place GPS (Global Positioning System) collars on 20 female bighorns. In order to access the sheep in their remote range, animals will be netted from a helicopter, quickly fitted with a collar, and released on site. The GPS collars are programmed to periodically record vital location data as the animals move across their range throughout the year. After two years, the collars will automatically drop off. Biologists will then recover the collars via radio-telemetry and download the data to computers, providing detailed information about habitat selection, travel routes and other factors (i.e. lamb production and survival) that are critical to ensuring the long-term survival of this bighorn population.
Winter is the best time to capture and collar bighorn sheep, and capture operations are scheduled to begin this week, as weather permits. Consequently, local residents and visitors may see low flying helicopters in the vicinity of Granite Canyon, Death Canyon, and northern portions of the Teton Range, as the operation takes place.
The Teton Range bighorn sheep population is Wyoming’s smallest and most isolated native herd, numbering just 100-125 animals. Federal and state biologists have been concerned for many years about the long-term survival of this particular herd. Due to a loss of historic low-elevation winter range, the herd now lives year-round at high elevation in the Teton Range, where because of their small population they are vulnerable to a single event—disease, harsh winter weather or avalanches—that could quickly reduce their numbers and lead to potential extirpation of the herd. Although broad scale information is available about bighorn sheep seasonal distributions, further detailed information on habitat selection, travel routes and movements is urgently needed and critical to the herd’s long-term persistence.
Growing recognition of the questionable future for this bighorn sheep population led to the formation of a Teton Range Bighorn Sheep Working Group in 1990—a group comprised of representatives from Wyoming Game and Fish Department, Bridger-Teton and Caribou-Targhee national forests, and Grand Teton National Park, as well as several individuals with expertise in bighorn ecology who are affiliated with non-governmental organizations.
Previous efforts to improve the Teton Range herd’s survival included seasonal closures of sheep winter ranges to reduce disturbance impacts during an especially stressful time of year, and the retirement of domestic sheep allotments in forest locations on the western slopes of the Teton Range. Although progress has been made in reducing some of the threats to the long-term survival of Teton Range herd, uncertainties still remain regarding their current distribution, and whether bighorn sheep avoid areas of human activity. Consequently, there is a critical need to further assess habitat selection patterns and general population status of this isolated sheep herd.