Space for the bighorns

sheep
/Payette National Forest

Remember some months back when a big blowup occurred over University of Idaho studies of whether diseases and other problems associated with domestic sheep might harm wild bighorn sheep?

Today, the upshot demonstrating why that was a blowup: A Payette National Forest record of decision restricting agricultural sheep to less than a third of the land they historically have used. It was written – and decided – by Payette Forest Supervisor Suzanne Rainville.

Here’s background from the decision:

Only portions of two bighorn sheep metapopulations remain on the Payette National Forest, one within Hells Canyon of the Snake River and the other among the Salmon River Mountains. Historically, these populations were likely connected by suitable habitats between the two major drainages and recently, bighorn sheep have been observed travelling from Hells Canyon to the Salmon River and back again. More than 10,000 bighorn sheep may have once lived in the Hells Canyon and surrounding mountains, but they were extirpated by the mid-1940s. Through reintroduction, 474 bighorn sheep were transplanted into Hells Canyon between 1971 and 2004. Seven die-offs have been reported since 1971. Today, the population is estimated at 850 animals. The Salmon River metapopulation was never extirpated. Winter population surveys conducted in 2001,2003, and 2004 document at least 508 bighorn sheep within the various drainages of the Salmon River and 210 bighorn sheep in the South Fork Salmon River and Main Salmon River. Historic accounts of major die-offs of bighorn sheep in the Salmon River Mountains began in approximately 1870. The population has experienced periodic die-offs and population decline since that time. The current estimated numbers of bighorn sheep in hunting units in and around the Payette National Forest has decreased 47 percent since 1981.

During the late 19th and early 20th centuries, large numbers of domestic sheep were grazed on the Payette National Forest. In 1915, 174,445 sheep were permitted to graze on the Payette National Forest. This number declined throughout the 20 century to around 18,300 in 2009. Today, four pennittees are authorized through term grazing permits to graze sheep on the Payette National Forest. Both statutory and case laws infer that a term grazing permit represents a privilege, not a prope11y right, to use National Forest System lands and resources. Procedures exist to modify or cancel term grazing permits. Although the Multiple Use Sustained Yield Act of 1960 directs that National Forests provide for multiple uses, such as range, it also states that some land will be used for less than all resources and periodic adjustments in use to conform to changing needs and conditions are allowed.

The decision says flatly what a number of others have danced around: “A long history of large-scale, rapid, all-age die-offs in bighorn sheep has been documented across Canada and the United States, many presumed associated with domestic animal contact (Shackleton 1999). Although limited knowledge of transmission dynamics exists (Garde et al. 2005), extensive scientific literature supports a relationship between disease in bighorn sheep populations and contact with domestic sheep.”

The decision limits to a large degree the areas where domestic sheep can roam.

And as to the research suggesting little danger from domestic sheep, there’s this:

“Despite the large body of evidence, the economic consequences of restricting domestic sheep grazing have polarized the issue. Some scientists and others, primarily from agricultural disciplines, contend that disease transmission between bighorn sheep and domestic sheep is not a relevant factor in bighorn sheep distribution and population declines in the wildland environment. I have taken these arguments into consideration while making my decision. I considered the degree of scientific uncertainty concerning the risk of foray contact and potential disease transmission. Arguably, much of the evidence is circumstantial; however, the compilation of cases throughout several decades does contribute to an increasing body of evidence that overwhelmingly demonstrates bighorn sheep near domestics are at risk for disease transmission, even though “contact” may not have actually been observed.”

She also says, “I am sure that my decision will not satisfy everyone.” That may be the one statement here everyone will agree with.

Call this one another big resource issue on the hoof.

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