Study Objectives: Assess the habitat selection strategies of the Teton Range bighorn sheep herd during winter and summer. Evaluate bighorn sheep avoidance of relatively high quality winter habitats due to human backcountry recreation. Document occurrence and timing of bighorn sheep use of retired domestic sheep allotments. Determine lamb survival to mid-summer, causes of adult mortality, summer diet composition, and summer time-budgets for GPS-collared sheep. eton Bighorn Sheep Project inter 2012 Update Wyoming Cooperative Fish and Wildlife Research Unit This is a collaborative research project involving the Wyoming Game & Fish Department, Grand Teton National Park, Bridger-Teton and Caribou-Targhee National Forests, and the Wyoming Coop Unit. Figure 1. Volunteer, Forest Dramis, rappels down a cliff to retrieve a collar that dropped on a rock ledge. The GPS-collars dropped off of the sheep in July 2010 after 2 ½ years of data collection. Retrieving the collars proved to be
Transcript
Study Objectives:
Assess the habitat selection strategies of the Teton Range bighorn sheep herd during winter and summer.
Evaluate bighorn sheep avoidance of relatively high quality winter habitats due to human backcountry recreation.
Document occurrence and timing of bighorn sheep use of retired domestic sheep allotments.
Determine lamb survival to mid-summer, causes of adult mortality, summer diet composition, and summer time-budgets for GPS-collared sheep.
Figure 2. Bighorn sheep locations from GPS-collar data.
Teton Bighorn Sheep ProjectWinter 2012 Update
Wyoming Cooperative Fish and Wildlife Research Unit
This is a collaborative research project involving the Wyoming Game & Fish Department, Grand Teton National Park, Bridger-Teton and Caribou-Targhee National Forests, and the Wyoming Coop Unit.
The GPS-collars dropped off of the sheep in July 2010 after 2 ½ years of data
collection. Retrieving the collars proved to be challenging (Figure 1), but we
successfully found all 25 collars after 2 months of effort.
Figure 1. Volunteer, Forest Dramis, rappels down a cliff to retrieve a collar that dropped on a rock ledge.
Data downloaded from the collars revealed bighorn sheep seasonal locations
and movement patterns (Figure 2).
Winter and summer habitat selection models were completed in fall 2011.
Predictive maps were produced from each model that identify the relatively highest quality bighorn sheep habitat
in the Teton Range (Figure 3).
Former domestic sheep allotments on the west slope of the Teton Range appear to be particularly important habitat for bighorn sheep during late
winter/early spring and throughout the summer
(Figure 4). These allotment retirements have virtually eliminated the risk of disease transmission
from domestic sheep to Teton Range bighorn sheep.
Seasonal habitat selection analyses for Chapter 1 are complete. These
analyses were lengthy due to unforeseen challenges with the GPS
Preliminary Findings:
Due to loss of migration and abandonment of traditional their traditional winter range, the herd is now wintering at high elevations on isolated, wind-swept ridgelines. Winter habitat availability and quality is likely a limiting factor for population growth.
The limited demographic data that we collected suggest that the population is stable, but very small. Winter mortalities from avalanches may significantly impact the population during some years.
Current and past exposure to disease is very low, indicating that the population has been isolated from surrounding herds for a long time. The herd lacks antibodies for many common diseases, meaning that future exposure could cause higher mortality rates than in other herds.
The GPS-collar data confirmed bighorn sheep use of former domestic sheep allotments on the west slope of the Teton Range.
Figure 3. Winter predictive map of bighorn sheep probability of use in the Teton Range. Red areas represent the relatively highest quality habitat for bighorn sheep. A similar map is available for summer.
Figure 4. Spring and summer bighorn sheep use of former domestic sheep allotments in the southern Teton Range. Pink areas were historically closed by the Forest Service. Red areas were retired with incentives from the Wyoming Wild Sheep Foundation and other partners.
Professional Presentations:
Wildlife Society Conference, November 2011 Wyoming Chapter of the Wildlife Society, December 2011
Public Presentations:
Wyoming Wild Sheep Foundation Annual Meeting, June 2011 Jackson Hole Rotary Club, September 2011 Jackson Hole Bird Club, October 2011 Jackson Hole & Greater Yellowstone Visitor Center, March 2012 Jackson Hole Conservation Alliance Info Lunch, March 2012
Figure 5. Bighorn sheep in Darby Canyon.
Seasonal habitat selection analyses for Chapter 1 are complete. These
analyses were lengthy due to unforeseen challenges with the GPS
Thank you to all of our contributors and cooperators for your continued support!
Wyoming Cooperative Fish and Wildlife Research Unit
University of Wyoming
Wyoming Game and Fish Department
Grand Teton National Park
Bridger-Teton National Forest
Caribou-Targhee National Forest
Teton County Conservation District
Jackson Hole Mountain Resort
Figure 6. Backcountry access gate on the Jackson Hole Mountain Resort. Data on backcountry recreation patterns collected at this and other points will be analyzed in spring 2012.
