Sheep station threatens grizzlies, say opponents

Jan 13, 2012

Typically, domestic sheep are not viewed as a major threat to grizzly bears, but a dispute about the potential effects of a USDA sheep research station on the threatened bears has turned this common wisdom on its head.

The Greater Yellowstone Coalition and National Wildlife Federation have been joined by at least one Bureau of Land Management (BLM) official in claiming that the Agricultural Research Service’s (ARS) U.S. Sheep Experiment Station (USSES), which straddles the Idaho-Montana border west of Yellowstone National Park, is hampering recovery efforts for the grizzly bear, which is listed as threatened under the Endangered Species Act.

Critics have argued that grazing sheep in grizzly habitat, particularly on ARS lands in the Centennial Mountains adjacent to the Primary Conservation Area for grizzlies outside of Yellowstone Park, could potentially cause the bears to prey on sheep, leading to their being lethally removed.

Opponents have also claimed that the presence of the domestic sheep will interfere with a key wildlife corridor, disrupting “connectivity” by blocking bears inhabiting the Greater Yellowstone Area from migrating to central Idaho and intermingling with other populations.

Gregory Lewis, station research leader at USSES, disagrees.

Lewis points out that the station has a long-standing policy of not lethally removing problem grizzlies, opting instead to move sheep away from predators. “We really have never had a grizzly bear problem,” said Lewis. “Anytime the herders see bear, or signs of bear or dogs start behaving as though there are bear, the herders have instructions to start moving the sheep away.”

A strict policy of not removing bear has not satisfied critics, however. In July 2011, USSES issued a draft environmental impact statement (DEIS) proposing to continue the grazing program on the station, including in the Centennial Mountains. BLM Dillon Field Office Manager Tim Bozorth maintained in his comments on the DEIS that exposure to sheep on the station could eventually habituate grizzlies to eating sheep off station, which could then lead to their eventual removal.

“It is time for the ARS USSES to cease to allow domestic sheep to occupy lands in the Centennial Mountains of Idaho and Montana,” stated Bozorth in his comments. “To continue to allow domestic sheep in this area will increase the likelihood of interactions between domestic sheep and grizzly bears. Even if the USSES does not take or seek lethal control actions against sheep-depredating grizzly bears, the fact that once grizzly bears have an interaction with domestic sheep there is a strong likelihood that the grizzly bear will repeat this interaction placing the grizzly bears at greater risk.”

Bozorth’s concerns were not echoed by the U.S. Fish and Wildlife Service (FWS), which is responsible for managing the threatened grizzlies.

In its official biological opinion on the DEIS, FWS called the effects of grazing on the grizzly’s recovery “insignificant,” estimating that the USSES grazing plan would only result in the removal on one bear over a period of 10 years. The opinion went on to state that “[t]he Sheep Station uses approximately l0 percent of the Centennial Range and less than one percent if considering the area occupied by sheep at a given time,” adding that “[g]razing on the proposed action area is very light with sheep using approximately six percent of available forage.”

The opinion also reported that bears with radio collars had been tracked through and around the sheep station, indicating that worries about lack of “connectivity” were ill-founded.

USSES was created in 1915 by executive order to provide production research for the sheep industry as well as information on sustainable grazing practices, invasive species management and other needs. The various components of the station comprise over 46,000 acres in Idaho and Montana managed by ARS, as well as several Forest Service allotments and one BLM allotment. Approximately 3,000 sheep are grazed on the facility.

Yet the existence of the station is now under scrutiny, with special interest groups and agency personnel like Bozorth arguing that the station threatens not only grizzlies, but also wolves, and prevents the reintroduction of bighorn sheep into the area due to concerns about transmission of disease.

It is a serious list of allegations. But if FWS is to be believed, at least there is reasonable certainty that the sheep pose little threat to the grizzly bears. — Andy Rieber, WLJ Correspondent