SPRINGDALE — Desert bighorn sheep are an iconic animal found at Zion National Park, and catching glimpses of them on the red cliff faces is a sought after part of a trip to the park. However, with reductions in habitat quality and disease across portions of their range, there were no documented sightings of bighorn sheep in the park between 1953 and 1973. In 1973, in cooperation with the Utah Division of Wildlife Resources and other agencies, bighorn sheep were reintroduced to the park. The population grew slowly until about 2008 when a rapid increase in numbers began
The biggest threat to Zion’s wild bighorn sheep is disease. Without displaying symptoms themselves, domestic sheep and goats can carry strains of pneumonia catastrophic to bighorn herds. Bighorn are curious about their domestic relatives and will often attempt contact with them, which increases the chance of disease transmission from domestic sheep to wild bighorn sheep. When this happens, fatality rates of up to 90% of a bighorn herd can occur, with significantly lower rates of lambing for years to come. With the expansion of the Zion herd, the risk of catastrophic disease had increased.
In order to mitigate this risk, Zion National Park, in collaboration with the Utah Division of Wildlife Resources, proposes to transplant desert bighorn sheep from the population inside the park to support other parts of the state’s bighorn population, and decrease the risk of disease transmission and potential for large scale mortality in the Zion herd, while contributing to the success of the regional population.
An environmental assessment has been prepared to examine the impacts of this proposed strategy. The No Action Alternative describes current management of the sheep, with occasional flights to obtain population estimates, and monitoring of the population. The park’s preferred alternative involves the use of helicopters (including in wilderness) to capture sheep for disease testing, GPS collaring, and periodic transplanting of a proportion of Zion’s sheep herd to areas outside the park with the intention of sustainably managing the herd size, habitat quality, and potential disease issues.
The public review and comment period runs through Sept. 25. Zion National Park invites the public to submit substantive comments including errors, omissions or additional information to consider in regard to desert bighorn sheep management.
The EA is available in electronic form on the NPS Planning, Environment & Public Comment website and may also be located in print at the Zion Human History Museum. Comments may be submitted online through PEPC or through the mail by writing to:
Zion National Park
ATTN: Bighorn Sheep EA
1 Zion Park Blvd.
State Route 9
Springdale, UT 84767