September 8, 2015 Martha Williamson District Ranger Divide Ranger District Rio Grande National Forest 13308 W. Highway 160 Del Norte, CO 81132 Dear Ranger Williamson: On behalf of the Wild Sheep Foundation s 6,000+ members, please accept this comment letter on the recent Environmental Assessment (EA) for the Snow Mesa Domestic Sheep Allotments. Based on the growing body of peer-reviewed, published scientific literature (see two attachments) on the topic of risk of contact/interaction between domestic sheep and goats and wild sheep, a thorough Risk-of-Contact (ROC) Assessment (Appendix A) completed by your USFS staff, scoping comments/concerns expressed by many (including WSF) over potential adverse impacts to a Tier II bighorn sheep population, and acknowledgement that other alternatives would not decrease risk of contact, WSF fully supports your proposed action in adopting Alternative 1, with the caveat that domestic sheep grazing not be authorized for the next two grazing seasons. As stated in the EA (page 7), it is anticipated that continuation of domestic sheep grazing for two full grazing seasons provides opportunities to analyze replacement allotments and to identify other grazing and forage options. In both the ROC Assessment and the EA, it is evident that nearby (either Divide [N=21 vacant] or Conejos Peak [N=13 vacant] Ranger Districts), alternative USFS grazing allotments, outside of important seasonal bighorn sheep range, are not readily available; in our opinion, while buying additional time may partially mitigate loss of AUMs by the displaced permittees, it clearly sidesteps the importance of making and implementing a time-sensitive resource management decision, consistent with USFS Washington Office direction on reducing risk and moving toward effective temporal and spatial separation between domestic and wild sheep. Again, as noted in the EA (page 9), WSF concurs there is no peer-reviewed literature that we are aware of that suggests bighorn sheep can graze with domestic sheep without concern for disease transmission. As stated, scientists from both sides of the issue also recommend that the species be kept separate until the disease transmission science is better understood. Much has changed, and much has been learned over the past ~38 years, since a 1977 EA was written to guide management of these allotments. Your EA (pages 10-11) list a multitude of reasons and justifications pertaining to the risk of contact and subsequent disease transmission from domestic sheep to bighorn sheep. Your multi-disciplinary staff is to be commended for a thorough job in conducting and analyzing a ROC Assessment; this EA accurately reflects the findings of the ROC Assessment, utilizing the best available science to help you make your decision. 412 Pronghorn Trail Suite B, Bozeman, MT 59718 tel: 1.307.527.6261 fax: 1.307.527.7117 email: info@wildsheepfoundation.org website: www.wildsheepfoundation.org
Table 3-3 (EA, page 46) clearly indicates that selection and implementation of either Alternative 2 or Alternative 3 are likely to result in a loss of viability of bighorn sheep in the planning area; the involved allotments remain high risk in both Alternatives 2 & 3. Alternative 1 is the logical, most defensible option to select and implement. Selection of Alternative 1 is further bolstered by the dollars and data presented in the Social and Economic portion of the EA. Alternative 1 is consistent with the Rio Grande NF Forest Plan, consistent with Washington Office and R2 Regional Forester direction, and the sole option that would decrease risk of contact and potential disease transmission between domestic sheep and bighorn sheep. Furthermore, Alternative 1 is consistent with and responsive to the R2 Regional Forester s list of Sensitive Species, including bighorn sheep. There really is only one reasonable option for you to select, in our opinion. WSF has closely read Table 5-1 (EA, pages 95-102), a summary of comments submitted during the initial scoping periods. It is clear to us that at least 10 organizations (CO Trail Foundation, CPW, RMBS, WWP, Continental Divide Trail Coalition, WSF, CWF, BCHA, HCCA, NWF) identified serious issues and concerns over continued domestic sheep grazing, while only the current permittee and the Navajo Nation urged continuation of domestic sheep grazing. Scoping is designed to identify issues and concerns, and alternatives are formulated to address those identified issues and concerns. We think this EA appropriately addresses the identified issues and concerns, and the range of alternatives either addresses risk of contact between domestic and wild sheep, or does not. WSF (and others) will keenly follow this upcoming USFS decision, and since WSF did comment during initial scoping, if necessary, WSF is also aware of 36 CFR 218 and the USFS objection process. Please know that the Wild Sheep Foundation, our Colorado affiliate (Rocky Mountain Bighorn Society), and a wide spectrum of in-state and out-of-state conservation interests support your proposed action of selecting and implementing Alternative 1. Please be sure to keep WSF informed as to your anticipated decision and implementation. Sincerely, Gray N. Thornton President & CEO Kevin Hurley Conservation Director cc: WSF Board of Directors WSF Conservation Committee WSF Professional Resource Advisory Board Rocky Mountain Bighorn Society 412 Pronghorn Trail Suite B, Bozeman, MT 59718 tel: 1.307.527.6261 fax: 1.307.527.7117 email: info@wildsheepfoundation.org website: www.wildsheepfoundation.org
Impacts of Disease on Bighorn Sheep Management Bighorn sheep (Ovis canadensis) are an iconic species of the American West. Wildlife managers have used reintroductions to restore wild sheep populations in response to declines over the past 150 years. However, diseases introduced by domestic sheep and goats have negatively impacted the size and viability of bighorn populations, reducing the effectiveness of reintroductions throughout public lands. Government agencies and nonprofits are exploring new management strategies to manage wild bighorn sheep and protect them from disease. A Rocky Mountain bighorn ram near Flathead Lake in Montana. Bighorns, once ubiquitous throughout the West, are threatened by disease introduced from domestic sheep (Credit: William Mullins). WHY ARE BIGHORNS VULNERABLE TO DISEASE? Bighorn sheep evolved in North America thousands of years before domestic sheep were introduced by European settlers. The domestic sheep brought novel diseases to which native sheep had never evolved a resistance. Bighorns also venture widely in search of resources and other herds. These journeys increase the chance of contact with domestic sheep. History of the Bighorn Sheep Bighorn sheep (Ovis canadensis) are large, wild ungulates native to western rocky and arid land. Their preferred habitats are barren and rugged areas containing steep hillsides or rocky outcrops that can be used to avoid predators. 1 Bighorns were one of the most abundant wild ungulates in the west. Population estimates range from 1.5 million to 2 million at the onset of the 19th century. 2,3 Populations declined with westward expansion of human populations due to overhunting, introduction of domestic sheep and goats, and overgrazing of rangelands. Bighorns were extirpated from Washington, Oregon, southwestern Idaho, northeastern California, Nebraska, the Dakotas, northern Nevada, and drastically reduced in other states by the end of the 19th century. 4,5 Restoration and Obstacles State and federal wildlife agencies have used translocations and federal protections to repopulate bighorn sheep habitat. 4,6,7 The Sierra Nevada subspecies (O. c. sierrae), and the peninsular Distinct Population Segment (DPS) of the desert subspecies (O. c. nelsoni) are listed as endangered under the Endangered Species Act. 8 Restoration and protection have allowed North American populations to grow from an estimated 25,000 in 1955 9 to 70,000 in the 1990 s 10, but growth has stagnated since despite continued efforts. There are currently an estimated 80,000 bighorns in North America. 11 The main obstacle to restoring populations is respiratory disease, most notably bacterial pneumonia. 5,12 Disease outbreaks have plagued bighorns for at least a century with reports from Colorado as early as 1885. 13 Evidence from wildlife scientists and managers associates contact with domestic sheep and goats and subsequent transfer of bacteria as the root cause for disease-caused mortality events. 4 A bighorn lamb. Lamb recruitment is reduced for several years after initial mortality events in herds affected by pneumonia infections (Credit: Tony Bynum).
Domestic Sheep and Pneumonia Domestic sheep, originally from Europe, have evolved resistance to several forms of respiratory diseases and are able to carry the disease-causing bacteria without clinical symptoms. 14 Several studies have shown that these bacteria are highly virulent in wild bighorn sheep and prove lethal after transmission from domestic sheep herds. 2,14 Numerous controlled experiments have shown more than 90% mortality in bighorn populations due to respiratory diseases within two months after exposure to domestic sheep. 15,16,17 Several disease -caused mortality events have been recorded in wild populations immediately after contact with domestic sheep in northeastern Oregon, central Colorado, Washington, California, Nevada, Montana, the Dakotas, and other locations. 12,16,18,19 The disease persists in bighorn populations following mortality events and reduces reproductive success, preventing regrowth of the population. 12 1.Krausman, Paul R. 2000. An introduction to the restoration of bighorn sheep. Restoration Ecology 8, no. 45: 3-5. 2.Lawrence, Paulraj K., et al. 2010. Transmission of Mannheimia haemolytica from domestic sheep (Ovis aries) to bighorn sheep (Ovis canadensis): Unequivocal demonstration with green fluorescent protein-tagged organisms. Journal of Wildlife Diseases 46: 706-717. 3.Wild Sheep Working Group. 2012. Recommendations for Domestic Sheep and Goat Management in Wild Sheep Habitat. Western Association of Fish and Wildlife Agencies. 4.Wehausen, John D., Scott T. Kelley, and Rob R. Ramey II. 2011. Domestic sheep, bighorn sheep, and respiratory disease: A review of the experimental evidence. California Fish and Game 97: 7-24. 5.Cahn, Maya L., et al. 2011. Disease, population viability, and recovery of endangered Sierra Nevada bighorn sheep. Journal of Wildlife Management 75, no. 8 (November): 1753-1766. 6.Singer, F.J., et al. 2000. Translocations as a tool for restoring populations of bighorn sheep. Restoration Ecology 8: 6-13. 7.Ramey II, R. R. 1993. Evolutionary genetics and systematics of North American mountain sheep. Ph.D. Thesis, Cornell University, Ithaca, New York, USA. 8.U.S. Forest Service. 2014. Index of species information; Ovis Canadensis. Accessed August 2014 from http://www.fs.fed.us/database/feis/animals/mammal/ovca/all.html 9. Buechner, H. K. 1960. The bighorn sheep in the United States, its past, present and future, Wildlife Monograph 4. 10. Valdez, R., and P. R. Krausman. 1999. Description, distribution, and abundance of mountain sheep in North America. Pages 3-22 in R. Valdez and P. R. Krausman, editors. Mountain sheep of North America. The University of Arizona Press, Tucson Arizona. 11.personal communication, Kevin Hurley, Conservation Director, Wild Sheep Foundation and Clay Brewer, Chair, WAFWA Wild Sheep Working Group. Circa 1850 9 Circa 1955 9 Circa 2012 22 The estimated ranges of bighorn sheep over time in the lower 48 states. The introduction of domestic sheep and goats, and historic overhunting led to large reductions in range size and local extirpations (Credit: Wild Sheep Foundation 22, WAFWA 3 ). Management Implications State wildlife managers, federal officials, and bighorn advocates have emphasized the need to reduce contact between wild and domestic sheep species, citing evidence of disease transfer. 3,20 But federal and state lands where most of the bighorn populations reside are also allotted for domestic sheep grazing. Land managers are tasked with balancing the needs of the domestic sheep industry with the conservation of the wild bighorns while accounting for several compounding factors. The foray behavior of wild sheep, where individuals will travel up to 50km searching for food and other herds, facilitates the spread of disease 21 while domestic sheep strays are common and increase interaction. Experimental trials to develop and test vaccines are underway, but are far from conclusive. If successfully developed, vaccinations would be logistically difficulty and expensive to administer 4 Separating domestic sheep allotments and wild sheep habitat is the most viable current management option. 3,5,16,20,21 U.S Forest Service and Bureau of Land Management personnel have developed a data-driven Risk of Contact Assessment tool which identifies and evaluates interspecies contact to help land managers make land use decisions that reduce the risk of contact. Close contact between a wild bighorn and a flock of domestic sheep grazing near Yellowstone River in Montana. Research has shown that the bighorns contract pneumonia from the sheep and then spread the disease rapidly among their own herds leading to high levels of mortality in addition to low reproductive capacity for several years (Credit: Kevin Hurley). 12.George, Janet L., et al. 2008. Epidemic Pasteurellosis in a bighorn sheep population coinciding with the appearance of a domestic sheep. Journal of Wildlife Diseases 44: 388-403. 13.Coggins, Victor L. 2010. Historic bighorn sheep disease outbreaks in western North America and mountain sheep extirpation from Oregon. In proceedings of Northern Wild Sheep and Goat Council s 17th Biennial Symposium, Hood River, OR. June 7-11. 14.Foreyt, William J., et al. 1994. Fatal pneumonia following inoculation of healthy bighorn sheep with Pasteurella haemolytica from healthy domestic sheep. Journal of Wildlife Diseases 30: 137-143. 15.Drew, Mark L., et al. 2014. Health status and microbial (Pasteurellaceae) flora of free-ranging bighorn sheep following contact with domestic ruminants. Wildlife Society Bulletin 38: 332-340. 16.Foreyt, William J., 1989. Fatal Pasteurella haemolytica pneumonia in bighorn sheep after direct contact with clinically normal domestic sheep. Am J Vet Res 50: 341-344. 17.Onderka, D. K. and W. D. Wishart. 1988. Experimental contact transmission of Pasteurella haemolytica from clinically normal domestic sheep causing pneumonia in Rocky Mountain bighorn sheep. Journal of Wildlife Diseases 24: 663-337. 18.Foreyt, W. J., and D. A. Jessup. 1982. Fatal pneumonia of bighorn sheep following association with domestic sheep. Journal of Wildlife Diseases 32: 594-602. 19.Coggins V. L. 1988. The Lostine Rocky Mountain bighorn sheep die-offs and domestic sheep. Proceedings of the Biennial Symposium of Northern Sheep and Goat Council 6: 57-64. 20.Schommer, Timothy J. and Melanie M. Woolever. 2008 A review of disease related conflicts between domestic sheep and goats and bighorn sheep. U.S. Forest Service. General Technical Report RMRS- GTR-209. 21.O Brien, Joshua M., et al. 2014. Incorporating foray behavior into models estimating contact risk between bighorn sheep and areas occupied by domestic sheep. Wildlife Society Bulletin 38: 321-331. 22. Wild Sheep Foundation. 2014. Wild Sheep Foundation website. Accessed September 2014 from www.wildsheepfoundation.org 09/2014
The Wildlife Society & American Association of Wildlife Veterinarians Joint Issue Statement Domestic Sheep and Goats Disease Transmission Risk to Wild Sheep Bighorn sheep and thinhorn sheep (Ovis canadensis and O. dalli), collectively referred to as wild sheep, are iconic species of western North America. Found in isolated, rugged, and extreme habitats of the continent, wild sheep are vital economic, social, and ecological components of these areas. The historic distribution of wild sheep in North America extended from Alaska to Mexico and east to the Dakotas, western Nebraska and west Texas. Population estimates of wild sheep ranged from 1.5 to 2 million at the onset of the 19th century (Seton 1909). Unregulated hunting, disease, competition for forage and space with domestic livestock, as well as habitat destruction and fragmentation led to precipitous declines in distribution and abundance through the early 1900s, with extirpations occurring in many regions (Buechner 1960). Wildlife managers have used translocations, habitat enhancement, and habitat protection to restore wild sheep populations, but recovery in some populations has been hampered by periodic disease outbreaks. Wild sheep are susceptible to a variety of diseases that affect herd viability. The most important diseases affecting wild sheep populations are respiratory infections that result in pneumonia. Bacteria of the family Pasteurellaceae (Pasteurella multocida, Mannheimia haemolytica and Bibersteinia trehalosi), and Mycoplasma ovipneumoniae are the most frequently isolated respiratory pathogens from wild sheep with pneumonia. Pneumonia caused by these organisms often results in the mortality of a large proportion of the population (Cox and Carlson 2012) across all age classes (referred to as an all age epizootic or die-off) and is typically followed by enzootic disease with multiple years of lamb mortality from pneumonia (WAFWA WHC 2014). This pattern of pneumonia in wild sheep has been documented in more than 70 peer-reviewed scientific publications. Incidences of pneumonia-related die-offs are frequently associated with the presence of domestic sheep and goats (George et al. 2008, Wehausen et al. 2011). Controlled research studies have confirmed that both Mannheimia hemolytica and Mycoplasma ovipneumoniae are transmitted to wild sheep upon contact with, or proximity to, domestic sheep (Besser et al. 2014, Lawrence et al. 2010, Wehausen et al. 2011). Domestic sheep and goats commonly carry these diseasecausing organisms which typically cause few deaths and little illness in domesticated adults and lambs (Martin 1996, Gilmour and Gilmour 1989). Contact between animals from range use overlap on public land and forays of wild sheep to nearby domestic herds on private in-holdings and visa-versa, is the crux of this wild-domestic animal controversy. While not all outbreaks of pneumonia in wild sheep have confirmed contact with domestic sheep or goats, the preponderance of scientific evidence shows that association with domestic sheep and goats poses a significant threat to the continued conservation and restoration of wild sheep populations. Management alternatives to reduce the impacts of respiratory disease on wild sheep are limited. There is currently no effective vaccine or treatment for pneumonia in bighorn sheep (Wehausen et al. 2011). Maintaining appropriate and reasonable spatial and temporal separation between wild sheep and domestic sheep and goats is the most effective tool currently available for minimizing risk of disease transmission between species (WAFWA WSWG 2012). www.wildlife.org AAWV Approved March 5, 2015 www.aawv.net TWS Approved March 8, 2015
Proactively protecting and managing the health of wild sheep populations is essential to the continued success of restoration, conservation and management efforts in North America. Managers must take appropriate steps to prevent epizootic events that reduce herd health and performance. This includes taking precautions to prevent transmission of pathogens between wild sheep during relocations. Appropriate, reasonable and effective solutions will be difficult, if not impossible to achieve, until the risk of disease transmission from domestic sheep and goats to wild sheep is widely acknowledged and substantially reduced. Stakeholder groups benefit when disease risk is managed to minimize the potential transmission of pathogens. The policy of The Wildlife Society and the American Association of Wildlife Veterinarians regarding the risk of disease transmission from domestic sheep and goats to wild sheep is to: 1. Accept that peer-reviewed, published science has consistently demonstrated the occurrence of disease transmission from domestic sheep and goats to wild sheep upon contact or proximity. 2. Recognize that disease transmission from domestic sheep and goats to wild sheep is a significant risk factor for the conservation and restoration of wild sheep populations. 3. Emphasize the need for developing and implementing disease management strategies to address chronically infected wild sheep populations. 4. Acknowledge the importance of science-based assessments of disease risk between wild sheep and domestic sheep and goats, and promote strategies to reduce the disease transmission and mitigate disease outbreaks. 5. Recognize effective temporal and spatial separation of domestic sheep and goats from wild sheep as the only currently available management solution for preventing or minimizing disease transmission and advocate for proactive and cooperative management strategies for achieving such separation. 6. Recognize alternative management strategies are being developed, and until stakeholder agreements are negotiated, co-mingling of domestic sheep and goats with wild sheep may result in the continued loss of wild sheep from disease, and wildlife managers may have to cull infected wild sheep herds to reduce the risk of further disease transmission. 7. Recognize some wild sheep populations may harbor pathogenic organisms potentially detrimental to other wild sheep and translocation of animals can spread the pathogens they carry. Translocation of wild sheep should occur following determination that disease transmission risk is low and conservation benefits are high. 8. Emphasize the importance of monitoring herd health following relocations or disease events. 9. Promote increased cooperation and communication among all stakeholders and public education programs to articulate the risks and impacts of disease transmission between wild sheep and domestic sheep and goats. www.wildlife.org AAWV Approved March 5, 2015 www.aawv.net TWS Approved March 8, 2015
The Wildlife Society s Position Statement on Livestock Grazing on Rangelands in the Western U.S. supports livestock grazing management on rangelands that guards against the potential for disease transmission between domestic livestock and wildlife (TWS 2010). The mission of the Wildlife Society s Wildlife Diseases Working Group is to promote better scientific understanding of the causes and consequences of disease in ecosystems and wildlife populations; to apply the principles of wildlife science, ecology, and epidemiology to the prevention and management of diseases in wildlife; to foster education and transfer of information on diseases to wildlife management professionals and the public; and to apply this knowledge to enhance the health and conservation of wildlife populations and their interactions with humans and domestic animals (TWS 2014). The American Association of Wildlife Veterinarians includes as their mission to stress the importance of the interrelationships of humans, domestic animals, and wildlife as reservoirs of disease and to educate about the importance of wildlife preventive medicine and disease in relation to the wildlife resource and domestic species. (AAWV 2014) It is under these baseline objectives and policies which these organizations issue this joint statement. Literature Cited American Association of Wildlife Veterinarians (AAWV). 2014. http://aawv.net. Last viewed December 28, 2014. Besser, T.E., E. F. Cassirer, K.A. Potter, K. Lahmers, J. L. Oaks, S. Shanthalingam, S. Srikumaran, and W. J. Foreyt. 2014. Epizootic Pneumonia of Bighorn Sheep following Experimental Exposure to Mycoplasma ovipneumoniae. Browning GF, ed. PLoS ONE. 9(10):e110039. doi:10.1371/journal.pone.0110039. Buechner, H.K., 1960. The Bighorn Sheep in the United States, Its Past, Present, and Future. Wildlife Monograph 4, The Wildlife Society, Washington, D.C. 174 pp. Cox, M. and T. Carlson. Wild Sheep Disease Events & Management Actions among Western States and Provinces. Presentation at the 2012 Western Association of Fish and Wildlife Agencies,Wild Sheep Working Group, Wildlife Professional s Meeting, Reno, NV. Foreyt, W. J., et al. 1994. Fatal pneumonia following inoculation of healthy bighorn sheep with Pasteurella haemolytica from healthy domestic sheep. Journal of Wildlife Diseases 30: 137-143. George, J. L., D. J. Marin, P. M. Lukacs, and M. W. Miller. 2008. Epidemic pasteurellosis in a bighorn sheep population coinciding with the appearance of a domestic sheep. J Wildl Dis. Apr; 44(2):388-403. Gilmour, N. J. L. and J. S. Gilmour. 1989. Pasteurellosis of sheep. In Pasteurella and Academic Press, London UK. Pp. 223-262. Pasteurellosis. Adam C. and Ruter J. M. (eds). Lawrence, P. K., S. Shanthalingam, R. P. Dassanayake, R. Subramaniam, C. N. Herndon, D. P. Knowles, F. R. Rurangirwa, W. J. Foreyt, G. Wayman, A. M. Marciel, S. K. Highlander, and S. Srikumaran. 2010. Transmission of Mannheimia haemolytica from domestic sheep (Ovis aries) to bighorn sheep (Ovis canadensis): unequivocal demonstration with green fluorescent protein-tagged organisms. Journal of Wildlife Diseases 46:706-717, and erratum (46:1346-1347). Martin, W. B. 1996. Respiratory infections of sheep. Comp. Immun. Microbiol. Infect. Dis. Vol. 19, No. 3, pp.171-179 Seton, E.T. 1909. Lives of Game Animals. Charles T. Branford, Co., Boston, Massachusetts. 780 pp. The Wildlife Society (TWS). 2010. Final Position Statement, Livestock Grazing on Rangelands in the Western U.S. http://wildlife.org/wpcontent/uploads/2014/11/livestock-grazing_march-2010_renewed-oct.15.pdf. Last viewed December 28, 2014. Wehausen, J. D., R. R. Ramey II, and S. T. Kelley. 2011. Domestic sheep, bighorn sheep, and respiratory disease: a review of experimental evidence. California Fish and Game 97:7-24. Western Association of Fish and Wildlife Agencies, Wildlife Health Committee. 2014. Bighorn Sheep Herd Health Monitoring Recommendations. 29 pp. Western Association of Fish and Wildlife Agencies,Wild Sheep Working Group. 2012. Recommendations for Domestic Sheep and Goat Management in Wild Sheep Habitat. 24 pp. www.wildlife.org AAWV Approved March 5, 2015 www.aawv.net TWS Approved March 8, 2015