Desert Bighorns Absent Since the Late 1990s May Be Returned By Fall
An advisory committee of informed local stakeholders is recommending that the state reintroduce desert bighorn sheep to the Santa Catalina Mountains in Tucson, AZ, where they were last seen in the late 1990s. The Pusch Ridge Wilderness once contained a robust native population of desert bighorn sheep. Credible population estimates ranged from an estimated 75 to 150 animals in 1979. The population’s decline beginning in the late 1980s cannot be attributed to any single factor. Contributing factors may include urban encroachment, human disturbance in sheep habitat, disease within the sheep population, fire suppression and predation.
The first 30 bighorn sheep are planned to be re-introduced to the Pusch Ridge Wilderness this fall, with the overall goal of more than 100 animals after three consecutive years of transplants. The total figure includes anticipated lamb births, estimated yearling survival rates, and natural mortality.
The project is being considered at this time due to four key factors that increase the likelihood of success:
- Improved habitat in much of the Catalinas resulting from the Bullock Fire in 2002 and the Aspen Fire in 2003, which removed unnaturally dense vegetation and reduced fuel loads.
- The Coronado’s anticipated use of prescribed fire in the Pusch Ridge Wilderness under FireScape, a landscape-scale fire and ecosystem management program, intended to re-establish a natural fire regime that reduces the risk of catastrophic wildfire, improves wildlife habitat and sustains the natural ecosystem processes.
- Current and projected availability of desert bighorn sheep from other healthy populations within the state from the Yuma and Mesa regions.
- Trail restrictions currently in place within the Coronado’s defined Bighorn Sheep Management Area that will be enforced and are important in preventing disturbance to reintroduced desert bighorn sheep, particularly during the lambing season.
“The goal of the Santa Catalina Bighorn Sheep Restoration Project is to restore a healthy, viable and self-sustaining population of desert bighorn sheep to the range that coexists with an equally healthy native predator population in a naturally functioning ecosystem,” said Regional Supervisor Raul Vega of Arizona Game and Fish Department (AGFD) in Tucson.
The reintroduced sheep will each be fitted with state-of-the-art satellite Global Positioning System collars that provide real time information about their location and any mortality events that may occur. This intensive monitoring effort will enable managers to make informed management decisions as information from collars becomes available. This technology comes with a cost; currently the overall project cost is estimated at $600,000 over the next three years. A public and private fund raising effort is currently underway to secure necessary funding to complete the project. Sponsorship opportunities are available through the Arizona Game and Fish Department at 520-628-5376 and tax deductible donations may be made at: http://adbss.org/donate.html.