Every spring, farmers in Chandler and Casa Grande, Ariz., move thousands of sheep out of the heat into northern Arizona for the summer and return them south in the fall. Some sheep are trucked part way, others are herded.
Now, an environmental group, the Western Watersheds Project, is suing to block their route, charging that herding the sheep through forests threatens the wild bighorn sheep. The anti-livestock group has filed a federal court lawsuit in Phoenix challenging a decision by the U.S. Forest Service (USFS) to allow domestic sheep to run across two forests.
In the fall, sheep are herded through parts of the Apache-Sitgreaves National Forest and the Tonto National Forest.
That is a trip taken by herds owned by Dwayne Dobson's Sheep Springs Sheep Co. in south Chandler and Joe Auza Jr. of the Joe Auza Sheep Co. in Casa Grande. Joe Auza Sr. trucks his herd part way.
One of the alleged risks to wild bighorn sheep is the transmission of a lung disease called Pasteurella from domestic sheep through contact.
"The bighorn are very social animals and love to interact with domestic sheep," said Jamie Shaffer of the Foundation for North American Wild Sheep based in Wyoming.
Beside interaction with domestic sheep, there is debate over additional causes for the drop in the bighorn population ranging from attacks by mountain lions and bears to the effects of severe winters and lack of food. There are an estimated 50,000 bighorns in the American West, down from an estimated 1.5 million.
Mark Pedersen, a manager at Sheep Springs, said environmentalists are comparing apples and oranges. He said their data comes from intermingling of bighorns and domestic sheep in the same pastures over months at a time. In contrast, he said, his sheep are in a bighorn area only a couple of days, the domestic sheep are vaccinated, are kept in a tight band and bighorns do not venture into the herd.
He pays the USFS every year for a permit to trail his sheep through the forest.
"The sheep are staying in a tight band with bells on them; there are dogs and a herder riding a horse," Pedersen said. "You can't tell me that wild bighorn sheep are going to run down and run into your (domestic) sheep. It's just highly unlikely."
Environmentalists are not convinced and want the USFS to do an environmental impact study. USFS spokeswoman Paige Rockett said a study has begun.
Meanwhile, the anti-livestock group is considering filing a request for a temporary restraining order to prevent the sheep run this fall.
Reprinted in part from The Arizona Republic