DIE-OFF CASE STUDIES

Highland/Pioneer Mountains, MT: 1994-1995

INTRODUCTION
The Highland and Pioneer Mountains are located in southwest Montana. The Highland Mountains (45° 44’ 8.48”N, 112° 30’ 1.72”W) are about 32 km (20 mi) south of Butte and Interstate 90 and primarily lie in Silver Bow and Madison Counties (Google Earth 2012). They are situated along the Continental Divide and Beaverhead Valley. Steep, tree-covered slopes form the majority of the Highland Mountains, and the range features a few peaks higher than 3,048 m (10,000 ft) (Reese 1985).

To the southwest, The Beaverhead Valley, Big Hole River, and Interstate 15 separate the Highland Mountains from the Pioneer Mountains, which are in Beaverhead County and about 40 km (25 mi) south of Butte (Google Earth 2012; Reese 1985; MFWP 2010). The Pioneer Mountains (45° 28’ 59.79”N, 112° 57’ 57.59”W) consist of the West Pioneers (gentler and not primary bighorn habitat) and the East Pioneers, which host bighorns and 3,353-meter (11,000-foot) peaks (Reese 1985; MFWP 2010). According to Reese: “The East Pioneers are a long, narrow stretch of high alpine peaks surrounded by lower forested foothills” (1985, 29). Bighorns in the Highland and Pioneer Mountains intermix. According to the Montana Department of Fish, Wildlife, and Parks (MFWP), “on numerous occasions, bighorn sheep rams have been observed crossing Interstate 15 between the Highland and East Pioneer mountain ranges” (2010, 203).

Highland/Pioneer Mountains Location Map

According to the BLM’s 1995 mountain sheep ecosystem management strategy, 44 percent of the “Pioneers and Highland Mtns” bighorn habitat bioregion is BLM land, 32 percent is other federal land (Beaverhead-Deerlodge National Forest), 4 percent is state land (managed by the Department of Natural Resources and Conservation), and 20 percent is private land (BLM 1995; MFWP 2010). Highland/Pioneer bighorn range is within state Bighorn Hunting District 340 (Highland District) (MFWP 2010). The MFWP provides a description of the biophysical geography and land ownership found in this bighorn range:

“The Highland area . . . includes the Highland Mountains and the northern portion of the East Pioneer Mountains near the town of Melrose . . . . The district is comprised of shrub grasslands (sagebrush, mountain mahogany, bluebunch wheatgrass, Idaho fescue), coniferous forests, and agricultural lands . . . . The majority of private land is in agricultural production, primarily cattle although there are several hobby sheep farms as well. . . .

Approximately 233 mi2 of the district . . . is currently occupied by bighorn sheep during some portion of the year . . . . Bighorn sheep winter range comprises approximately 188 mi2 of this district (16%); 23% is private land and 77% public, with the majority of public land being administered by the BLM. Based on past and current telemetry data and recent observations, the majority of the bighorn sheep population winters on public lands.

The vegetation within the occupied bighorn sheep range is predominantly   rocky terrain interspersed with sagebrush grassland, mountain mahogany, and   lodgepole pine and Douglas fir forest” (MFWP 2010, 202).

Wildlife managers reintroduced Rocky Mountain bighorns to the Highland and Pioneer Mountains in 1967. Highland/Pioneer bighorns shared their range with private land domestic sheep for decades before a 1994-1995 pneumonia outbreak contributed to reducing their numbers by 87 percent (Aune et al. 1998; Arthur et al 1998). Aside from MFWP’s management plan, no policy documents directly related to the Highland/Pioneer bighorn-domestic sheep situation were discovered, partly because no public land sheep grazing allotments exist in the area (MFWP 2010).

In the realm of wild-domestic sheep interaction policies, the Highland and Pioneer Mountains lacked clear buffers between bighorns and domestic sheep (Frisina 2012). Special sheepherder supervision rules, trailing restrictions, and grazing allotment alteration efforts were not applicable because the Highland and Pioneer Mountains had no domestic sheep grazing allotments (MFWP 2010). Domestic sheep presence was not considered before reintroduction. However, negotiation and education with local domestic sheep owners was attempted before the Highland/Pioneer outbreak. Bighorns that got near domestic sheep were most likely not removed from the wild. Agency coordination occurred with some possible tension, and funding difficulties were not an issue for bighorn-domestic sheep interaction management in the Highland and Pioneer Mountains (Frisina 2012). To better understand interaction policies that impacted the Highland/Pioneer bighorns, it helps to examine their population history before disease struck them.

BIGHORN POPULATION HISTORY PRIOR TO OUTBREAK
Rocky Mountain bighorns in the Highland/Pioneer population originally occurred in both the Highland Mountains and East Pioneer Mountains (Hoar, Worley, and Aune 1996). However, the Highland/Pioneer population is often just referred to as the Highlands population (MFWP 2010; Arthur et al. 1999; Hoar, Worley, and Aune 1996). The Highland/Pioneer bighorn population has a history of special local importance. The MFWP remarks:

“Bighorn sheep in the Highlands herd have been one of Montana’s best-known and premier wild sheep herds, both for hunting and wildlife watching. Because much of the annual range is within easy access and sight of Interstate 15 and several secondary roads, going out to “watch sheep” has been and continues to be a popular pastime of many local residents and wild sheep fans” (2010, 204).

The MFWP adds: “Second only to the Missouri Breaks herd in Montana for trophy status, the Highlands herd at one time was known as one of the best places to harvest a trophy ram” (2010, 204).

Over-hunting and livestock disease helped wipe out the original Highland/Pioneer bighorns in the early 1900s (MFWP 2010). Aune et al. provide more history:

“[Bighorns] were reintroduced to the area in 1967 when 27 sheep were transplanted from the Sun River. The initial transplant population was supplemented with 31 sheep in 1969. The population expanded in size and range up through the mid 1990’s so that sheep today [in 1998] extend across the Big Hole River and into the foothills of the Pioneer Mountains. The number of males in the population grew and the herd became well known for its trophy quality rams. The number of sheep was estimated [to be] 350-400. Harvests were increased in 1992 and 1993 to 39 and 40 sheep. In addition, 35 sheep were captured and transplanted from the population in 1992 to reduce sheep numbers. In 1993 the population was at an all time high” (1998, 50).

About 400 bighorns may have existed at the peak of the population, and over 300 were seen in the early 1990s. According to MFWP, “it was not uncommon for groups of 50 or more rams to be observed” (2010, 204). Such high numbers of bighorns increased the likelihood of interaction with domestic sheep.

NEARBY DOMESTIC SHEEP
Regarding the Highland/Pioneer population, Aune et al. remark that “bighorn sheep from this herd unit shared habitat with domestic sheep during all seasons” (1998, 57). They add: “Domestic sheep and bighorns coexisted in the Highlands-Pioneers for nearly 20 years before a pneumonia outbreak” (1998, 64). The MFWP provides more detail:

“Historically, the Highlands bighorn sheep range has overlapped with two small bands of domestic sheep located on private land near Maiden Rock in the East Pioneer Mountains. Semmens (1996) observed bighorn sheep using agricultural areas that supported these domestic sheep bands throughout the year, with the majority of use occurring in the fall. Bighorn sheep have used this overlapping area with domestic sheep for more than 20 years prior to the die-off in the mid-1990s and no problems with diseases had arisen in the past, although die-offs of wild sheep have been linked to domestic sheep and goat interactions in other areas. Presently, several domestic sheep hobby farms operate within proximity of the Highlands wild sheep range. There are no BLM or Forest Service sheep allotments, active or retired, in the Highlands or East Pioneer Mountains. The need to monitor the Highlands herd on a regular basis for domestic sheep interactions and herd health continues to be a management concern” (2010, 206).

If wild-domestic sheep interaction in the Highland and Pioneer Mountains was more of a concern in the early 1990s, it may have prevented or at least delayed a devastating pneumonia outbreak.

OUTBREAK SUMMARY
From 1994-1995, bighorns in the Highland/Pioneer Mountains experienced a pneumonia outbreak (Arthur et al. 1999; Aune et al. 1998). The MFWP said “the die-off was attributed to a pneumonia-lungworm complex” (2010, 203). A 1992-1993 study “indicated an increased lungworm load and some significant gastrointestinal parasites within the population” (Aune et al. 1998, 50). Aune et al. went on to summarize the subsequent disease outbreak, which started in October 1994 (Aune et al. 1998):

“By late November 1994, sheep hunters in the area reported observing clinical signs of pneumonia. Diagnostic work from two sheep mortalities confirmed pneumonia complex with strong evidence of chronic lungworm infection. Sheep mortalities continued to be recorded from December 1994 through March 1995. The population declined 87 percent and the current population contains less than 50 individuals” (1998, 50).

Researchers carried out carcass searches during the outbreak (Aune et al. 1998). A variety of pneumonia bacteria were found to have infected dead bighorns. Researchers also discovered seroprevalence for antibodies for P13 (a type of respiratory virus) among bighorns tested and stated that it “indicated significant challenge for bighorns in the Highlands-Pioneer herd unit prior to an epizootic” (Aune et al. 1998, 59). However, biologists did not discover the P13 virus itself in bighorn lung tissue. Researchers also hypothesized that high parasite loads may have predisposed the Highland/Pioneer bighorns to bacterial infection (Aune et al. 1998). Additionally, Aune et al. mention that:

“The Highlands-Pioneer pneumonia epizootic was also characterized by a unique infection with the highly pathogenic Pasteurella haemolytica [now classified as M. haemolytica] type A2 as well as the more common type, T-3,4. It is likely that the cytotoxic A2 isolate originated from domestic sheep that share habitat with these bighorn sheep yearlong. Several reports of bighorn rams breeding with and mingling with domestic sheep ewes were recorded prior to the pneumonia outbreak” (1998, 64).

Aune et al. go on to speculate that the significant increase in the Highland/Pioneer bighorn population in the early 1990s increased the risk of wild-domestic sheep disease transmission (1998). Despite subsequent augmentation transplants, Highland/Pioneer bighorn counts performed after the 1990s disease outbreak have regularly shown fewer than 50 animals. Lamb recruitment has also remained suppressed. For example, in 2008, over 90 percent of new lambs died from pneumonia (MFWP 2010). In early 2013, an estimated 50-75 bighorns inhabited the Highland and Pioneer Mountains (Boccadori 2013).

POLICY DOCUMENTS
The policies of Montana’s 2010 bighorn plan are too recent to apply to this disease outbreak (MFWP 2010). Much of the Highland/Pioneer bighorn range was/is on BLM land, so the BLM’s 1992 Guidelines for Domestic Sheep Grazing in Bighorn Sheep Habitats would have applied to sheep grazing on BLM land in the area (BLM 1995). However, there were no public domestic sheep grazing allotments in Highland/Pioneer bighorn range. Known domestic sheep occurred on private land, so the 1992 guidelines were not necessarily applicable or enforceable (MFWP 2010). Additionally, an inquiry to the BLM’s Butte Field Office did not reveal any site-specific BLM bighorn-domestic sheep interaction guidelines in the Highland or Pioneer Mountains (LaMarr 2012). An examination of the BLM’s 1979 Management Framework Plan: Dillon Summary, Montana (covered the Highland/Pioneer Mountains at the time of the outbreak) also revealed no BLM bighorn-domestic sheep interaction policies (BLM 1979).

Highland/Pioneer bighorn habitat includes portions of the Beaverhead-Deerlodge National Forest, which was created from the melding of two national forests into one administrative unit in 1996 (USFS 2012). Thus, a look at the management plans in place for both the Beaverhead and Deerlodge National Forests in 1994 is relevant to this analysis. An examination of the 1986 plan for the Beaverhead National Forest revealed no wild-domestic sheep interaction policies (USFS 1986).

Though not directly addressing bighorn-domestic sheep interactions, the 1987 plan for the Deerlodge National Forest refers to policy regarding bighorn conflicts with livestock (USFS 1987). A standard of the plan is to: “Protect occupied bighorn sheep and mountain goat range during resource activities. Include requirements in project plans for livestock, timber, or other resource development to avoid or mitigate impacts on the range. Resolve conflicts in favor of these species” (USFS 1987, II-18). An inquiry to the Beaverhead-Deerlodge National Forest reveals that no USFS bighorn-domestic sheep interaction policies were in place in the Highland or Pioneer Mountains in 1994-1995 because there were no domestic sheep grazing allotments in the Forest (Rohrbacher 2012).

Now that a summary has been offered on the 1994-1995 Highland/Pioneer Mountains bighorn die-off and its related factors, important background information is in place to provide a better understanding of particular policies relevant to that outbreak. Policies are analyzed through questions that form the nine policy analysis criteria.

POLICY ANALYSIS CRITERIA

1.) Were clearly defined buffer zones established to ensure separation of bighorns and domestic sheep?

Answer and Explanation
Buffer zones were not in place (Frisina 2012). Michael R. Frisina was the MFWP biologist in Butte at the time of the outbreak. He emphasizes that the separation issue was not a consideration when the Highland/Pioneer population was established in 1967 (2012).

2.) Were special supervision rules in place for sheepherders?

Answer and Explanation
This policy analysis criterion is not applicable because, according to MFWP: “There are no BLM or Forest Service sheep allotments, active or retired, in the Highlands or East Pioneer Mountains” (2010a, 206). Small bands of domestic sheep on private land were likely the only sheep in the area (MFWP 2010).

3.) Were domestic sheep trailing restrictions in place to ensure separation?

Answer and Explanation
This criterion is not applicable because of the lack of domestic sheep allotments in Highland/Pioneer bighorn range (MFWP 2010).

4.) Were policies in place or was consideration taken regarding the concept of prohibiting bighorn reintroduction to the site if it hosted domestic sheep?

Answer and Explanation
Domestic sheep presence in the Highland and Pioneer Mountains was not considered prior to reintroducing bighorns because, back in 1967, the bighorn-domestic sheep disease issue was not a prominent concern for Montana biologists (Frisina 2012).

5.) Before the disease outbreak, was any effort made to buy out nearby domestic sheep grazing allotments or convert them to cattle?

Answer and Explanation
This criterion is not applicable because of the absence of public land domestic sheep grazing allotments in Highland/Pioneer bighorn habitat (MFWP 2010).

6.) Were other forms of negotiation and/or education attempted with local stakeholders regarding the issue of bighorn-domestic sheep disease transmission?

Answer and Implementation
Efforts to negotiate with domestic sheep owners were attempted in the range of Highland/Pioneer bighorns. According to Frisina: “Efforts were made to discuss concerns with private land owners, but the primary landowner was not cooperative and refused to take the issue seriously. The other landowner made a concerted effort to keep his domestic sheep away from wild sheep” (2012).  

7.) If wandering bighorns got too close to domestic sheep, were they ever removed from the wild in or near this location?

Answer and Explanation
While this question was written with wild sheep in mind, it could be read either way. Regarding MFWP policy, Frisina remarked: “There is no authority to remove domestic sheep from private lands” (2012). The fact that MFWP allowed bighorns to mingle with domestic sheep for over 20 years before the outbreak (Aune et al. 1998) indicates that it is highly unlikely any efforts were made to fatally remove bighorns to prevent disease spread.

8.) Did coordination and/or tension exist between different levels (federal, state, local) of government management agencies regarding bighorn-domestic sheep interaction?

Answer and Nature
Coordination existed (Frisina 2012), and tension seems likely. According to Frisina: “MFWP cooperated with the BLM in developing guidelines regarding bighorn sheep/wildlife sheep interactions. This was a long slow bureaucratic process that never got very far at the local level” (2012).

9.) Did you encounter funding difficulties regarding bighorn-domestic sheep interaction management?

Answer and Explanation
For wild-domestic sheep interaction management in the Highland and Pioneer Mountains, funding difficulties were not a concern (Frisina 2012). Frisina remarked that “there was nothing FWP could do about the existence of domestic sheep on private lands. The landowners did not want to have anything to do with government funding to eliminate domestic sheep from the area” (2012).

POLICY EFFICACY SUMMARY
Regarding management of wild and domestic sheep in the Highland/Pioneer Mountains before that area’s die-off, no especially effective policies stand out, partly because many policies were not applicable due to that region not hosting domestic sheep grazing allotments (MFWP 2010). The Highland/Pioneer Mountains lacked buffers between wild and domestic sheep (Frisina 2012), but with no public sheep allotments, buffer policies could not be feasibly enforced. Not considering the presence and threat of domestic sheep before reintroducing bighorns to the Highland/Pioneer Mountains (Frisina 2012) represents a significant policy gap that may have contributed to the area’s 1994-1995 disease outbreak. Negotiation/education concerning local sheep producers may have had some successes that delayed disease (i.e. according to Frisina, one producer cooperated with MFWP), but it was ineffective, considering a primary domestic sheep producer did not take the disease issue seriously. Agency coordination concerning the Highland/Pioneer wild-domestic sheep situation was also slow and did not get far (Frisina 202), which indicates that it was ineffective.

REFERENCES
Arthur, Steven M., Ian Hatter, Alasdair Veitch, John Nagy, Jean Carey, Jon T. Jorgenson, Raymond Lee,  John Ellenberger, John Beecham, John J. McCarthy, Gary Schlichtemeier, Larry T. Gilbertson, Bill Dunn, Don Whittaker, Ted A. Benzon, Jim Karpowitz, George Tsukamato, Kevin Hurley, Steven G. Torres, Craig Mortimore, Mike Oehler, Patrick Cummings, Craig Stevenson, Eric Rominger, and Doug Humphreys. 1999. Appendix A: Wild sheep status questionnaires. In proceedings of 2nd North American Wild Sheep Conference, Reno, NV. April 6-9.

Aune, Keith, Neil Anderson, David Worley, Larry Stackhouse, James Henderson, and Jen’E Daniel. 1998. A comparison of population and health histories among seven Montana bighorn sheep populations. In proceedings of Northern Wild Sheep and Goat Council’s 11th Biennial Symposium, Whitefish, MT. April 16-20.

Boccadori, Vanna. 2013. Wildlife Biologist (Butte Area), Montana Department of Fish, Wildlife, and Parks. Interview by author. Conducted by e-mail. February 23.

Bureau of Land Management (BLM). 1979. Management Framework Plan: Dillon Summary, Montana. Butte, MT. [govt. doc.]

Bureau of Land Management (BLM). 1995. Mountain Sheep Ecosystem Management Strategy in the 11 Western States and Alaska. N.p. ftp://ftp.blm.gov/pub/blmlibrary/BLM publications/StrategicPlans/Wildlife/ MountainSheepEcosystem.pdf (accessed May 11, 2012). [govt. doc.]

Frisina, Michael R. 2012. Adjunct Professor of Range Sciences, Montana State University. Interview by author. Conducted by e-mail. July 23.

Hoar, Kerrie L., David E. Worley, and Keith E. Aune. 1996. Parasite loads and their relationship to herd health in the Highlands bighorn sheep herd in southwestern Montana. In proceedings of Northern Wild Sheep and Goat Council’s 10th Biennial Symposium, Silverthorne, CO. April 29-May 3.

LaMarr, Sarah. 2012. Wildlife Biologist (Butte Field Office), Montana Department of Fish, Wildlife, and Parks. Interview by author. Conducted by e-mail. June 12.

Montana Department of Fish, Wildlife, and Parks (MFWP). 2010. Montana Bighorn Sheep Conservation Strategy: 2010. Helena. http://fwpiis.mt.gov/content/getItem.aspx?id =397 46 (accessed October 15, 2011). [govt. doc.]

Reese, Rick. 1985. Montana mountain ranges. Helena: Montana Magazine, Inc.

Rohrbacher, Art. 2012. Wildlife Program Manager/Acting Planning, Budget & Resources Staff Officer (Beaverhead-Deerlodge National Forest), U.S. Forest Service. Interview by author. Conducted by e-mail from. June 11.

Aune, Keith, Neil Anderson, David Worley, Larry Stackhouse, James Henderson, and Jen’E Daniel. 1998. A comparison of population and health histories among seven Montana bighorn sheep populations. In proceedings of Northern Wild Sheep and Goat Council’s 11th Biennial Symposium, Whitefish, MT. April 16-20.

U.S. Forest Service (USFS). 1986. Forest Plan: Beaverhead National Forest. Dillon, MT. [govt. doc.]

U.S. Forest Service (USFS). 1987. Forest Plan: Deerlodge National Forest. Butte, MT. [govt. doc.]

U.S. Forest Service (USFS). 2012. Beaverhead-Deerlodge National Forest. http://www.fs. usda.gov/bdnf (accessed May 12, 2012).