United States Department of Agriculture Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Forest Service Humboldt-Toiyabe National Forest National Forests Austin/Tonopah Ranger District Ranger District May 2018
For More Information Contact: Lance Brown, District Ranger Austin/Tonopah Ranger District 100 Midas Canyon Road P.O. Box 130 Austin, Nevada 89310 Phone: (775) 964-2671 Fax: (775) 964-1451
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Contents
Introduction ...... 1 Proposed Project Area ...... 1 Need for the Proposal ...... 3 Consistency with Forest Plan Direction ...... 6 Management Area 9 – Toquima ...... 6 Range Management ...... 6 Wild Free-Roaming Horse and Burros ...... 7 Riparian Areas ...... 7 Wildlife and Fish ...... 7 Greater Sage-Grouse Forest Plan Amendment #17 ...... 8 Consistency with Other Direction ...... 8 Public Involvement and Proposal Development ...... 9 Tribal Consultation and Coordination ...... 10 Identification of Issues ...... 10 Proposed Action and Alternatives ...... 11 Alternatives Considered in Detail ...... 11 Alternative 1—No Action ...... 11 Alternative 2—Proposed Action ...... 11 Alternative 3 ...... 13 Adaptive Management Adjustments Based on Monitoring for All Action Alternatives ...... 15 Adjustments Based on Utilization Monitoring ...... 15 Adjustments Based on Changes in Plant Composition ...... 16 Adjustments Based on Genetic Diversity ...... 17 Adaptive Management Adjustments Based on Population Monitoring for Alternative 3 Only 17 Design Features Common to All Action Alternatives ...... 17 General ...... 17 Cultural Resources...... 17 Sensitive Plants ...... 18 Wildlife ...... 18 Noxious and Invasive Weeds ...... 18 Environmental Consequences ...... 19 Issues Not Analyzed in Detail ...... 19 Wild Horses ...... 19 Roadless Areas ...... 19 Cultural Resources...... 20 Mineral and Energy Resources ...... 21 Climate Change ...... 21 Issues Analyzed in Detail ...... 21 Activities Considered in the Cumulative Effects Analysis for all Alternatives ...... 21 Wild Burro Management outside the Hickison Wild Burro Territory ...... 21 Grazing Allotment Management and Range Developments ...... 22 Mineral Exploration...... 22 Recreation ...... 23 Wild Burros ...... 23 Rangeland Resources...... 63 Water Quality ...... 81 Soils ...... 84 Wildlife ...... 87
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Botanical Resources ...... 118 Social and Economic Resources ...... 143 Agencies and Persons Consulted ...... 160 References ...... 161
List of Tables
Table 1. Hickison Wild Burro Territory Desired and Existing Conditions ...... 5 Table 2. Maximum grass or forb utilization levels for wild burros in Hickison Wild Burro Territory ...... 15 Table 3. Maximum shrub or tree utilization levels for wild burros in Hickison Wild Burro Territory ...... 16 Table 4. Seasonal distribution and forage use patterns on grazing allotments ...... 25 Table 5. General distribution inside and outside the joint management area ...... 25 Table 6. Wild burro distribution inside the Hickison Joint Management Area ...... 25 Table 7. Wild burro distribution outside the Hickison Joint Management Area ...... 26 Table 8. Annual distributions between administrative areas ...... 26 Table 9. Sufficient forage, water, cover, and space yearlong ...... 27 Table 10. Current permitted livestock use for allotments within the wild burro territory ...... 65 Table 11. Authorized livestock use for allotments within the Wild Burro Territory, in head months (2003–2017) ...... 65 Table 12. Hot Springs winter allotment utilization monitoring in potential key areas ...... 68 Table 13. Hot Springs winter allotment utilization standards, maximum percent utilization by key species ...... 70 Table 14. Crosswalk of terms used in Toiyabe forest plan, the Central Nevada Riparian Field Guide, and matrices ...... 71 Table 15. Condition-trend transects in grazing allotments and Hickison Wild Burro Territory ... 72 Table 16. Recommended relative plant cover for the Desert Shrub matrix ...... 74 Table 17. Recommended relative plant cover for the Black Sagebrush matrix ...... 74 Table 18. Recommended relative plant cover for the Pinyon-Juniper Woodland matrix ...... 74 Table 19. Recorded relative plant cover for Desert Shrub Group (Spencer Hot Springs Quad 001), 2010 ...... 75 Table 20. Recorded relative plant cover for Black Sagebrush Group (Spencer Hot Springs Quad 002) ...... 75 Table 21. Recorded relative plant cover for Pinyon-Juniper Woodland Group (Henry Meyer Canyon Plot) ...... 75 Table 22. Recorded relative plant cover for Pinyon-Juniper Woodland Group (Stoneberger Plot) ...... 76 Table 23. Acres of trend and suitability classification in the Hot Springs winter allotment (USDA Forest Service 1970) ...... 76 Table 24. Soils found within the Hickison Wild Burro Territory ...... 86 Table 25. Dominant vegetation types found in the Hickison wildlife analysis area ...... 88 Table 26. Federally listed wildlife species considered...... 89 Table 27. Region 4 sensitive species of concern considered...... 89 Table 28. Species carried forward for analysis...... 90 Table 29. Summary of effects determinations for threatened (T), endangered (E), proposed, and sensitive (SS) wildlife species ...... 91 Table 30. Intermountain Region (R4), Humboldt-Toiyabe National Forest threatened, endangered, proposed, and sensitive plant species, and their known or potential presence within the Austin/Tonopah Ranger District...... 118
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Table 31. Other rare plant (watch list) species known or potentially present within the Austin/Tonopah Ranger District...... 121 Table 32. Austin/Tonopah District sensitive plant species potentially occurring in or adjacent to the project area ...... 122 Table 33. Austin/Tonopah District other rare plant species potentially occurring in or adjacent to the project area ...... 126 Table 34. Summary determinations for Intermountain Region threatened, endangered, proposed, and sensitive plant species with the potential to occur on the Austin/Tonopah Ranger District ...... 142 Table 35. Resource indicators and measures for the social and economic resources existing condition ...... 144 Table 36. Population and demographics...... 145 Table 37. Economic characteristics ...... 146 Table 38. Resource indicators, measures, and effects for alternative 1 ...... 149 Table 39. Resource indicators and measures for alternative 2 direct and indirect effects ...... 153 Table 40. Resource indicators and measures for alternative 3 direct and indirect effects ...... 156 Table 41. Summary comparison of how the alternatives address the key issues ...... 157 Table 42. Summary comparison of environmental effects to socioeconomic resources ...... 158
List of Figures
Figure 1. Hickison Wild Burro Territory project area ...... 2 Figure 2. Typical color and conformity of wild burros on the Hickison Joint Management Area 24 Figure 3. Grazing allotments in the project area ...... 66 Figure 4. Authorized livestock numbers compared to wild burro population (1998 to 2017) ...... 67 Figure 5. Key area study plots within and near the Hickison Wild Burro Territory ...... 69 Figure 6. Trend study plots located within and near the wild burro territory ...... 73 Figure 7. Water sources, grazing allotments, and burro management areas in and around the Hickison Wild Burro Territory ...... 82 Figure 8. Soil erosion risk within the Hickison Wild Burro Territory ...... 85
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Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Acronyms
Below are commonly used acronyms in this document. For further information on these acronyms or definitions of technical terms used in this document, please reference the forest plan glossary located in chapter 6 of the Toiyabe forest plan at: http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5143054.pdf.
APHIS: Animal and Plant Health Inspection NHPA: National Historic Preservation Act Service (USDA) of 1966 AU: animal unit NF: national forest (Forest Service, USDA) AUM: animal unit months NPO: National Program Office (BLM, BLM: Bureau of Land Management Reno, NV) CEQ: Council on Environmental Quality PGH: preliminary general habitat CFR: Code of Federal Regulations PPH: preliminary priority habitat ESA: Endangered Species Act of 1973 PZP: porcine zona pellucida FSH: Forest Service Handbook RMP: resource management plan (BLM). Synonymous with forest plan. FSM: Forest Service Manual SHPO: State Historic Preservation Office GPS: global positioning system SOP: standard operating procedures HA: herd area (BLM) TES: threatened, endangered, or sensitive HM: head month species HMA: herd management area (BLM). TMP: territory management plan Synonymous with wild burro territory. USC: United States Code MINT: May impact individuals or populations but not likely to result in a trend USDA: United States Department of to Federal listing or loss of viability for the Agriculture population USDI: United State Department of Interior MUD: multiple use decision (BLM) USFS: United States Forest Service NDOW: Nevada Department of Wildlife WHT: wild horse territory NEPA: National Environmental Policy Act WO: Washington Office (Forest Service, of 1969 USDA) NI: No impact to individuals or populations
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Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Introduction The U.S. Forest Service is proposing to establish appropriate management levels and undertake management actions on the 52,570-acre Hickison Wild Burro Territory, a congressionally designated Forest Service wild burro territory on the Austin/Tonopah Ranger District of the Humboldt-Toiyabe National Forest. If approved by the responsible official, the proposed action would establish lower and upper appropriate management levels, authorize population management actions (gathering, removing, and augmenting burros under certain conditions), adopt design criteria, and establish an adaptive management approach to appropriately respond to wild burro population growth or declines. See the “Proposed Action and Alternatives” section for more details.
We have prepared this environmental assessment to determine if effects of the proposed action may be significant and thus require the preparation of an environmental impact statement. If determined that there are no significant effects based on this analysis and the consideration of public input, we will summarize the determination in a finding of no significant impact and decision notice authorizing the Austin/Tonopah Ranger District staff to implement the project. By preparing this environmental assessment, we are fulfilling agency policy and direction to comply with the National Environmental Policy Act and other relevant Federal and State laws and regulations. For more details of the proposed action, see the “Proposed Action and Alternatives” section of this document.
This document is tiered to the final environmental impact statement and planning record supporting the 1986 Toiyabe National Forest Land and Resource Management Plan (forest plan) (USDA Forest Service 1986), including monitoring reports. Detailed information that supports the analyses presented in this document is incorporated by reference, including specialists’ reports for each resource, and is contained in the project planning record unless noted otherwise. Proposed Project Area The project area is located on the Austin/Tonopah Ranger District approximately 20 miles east of Austin, Nevada, in Lander and Nye Counties (figure 1). The Hickison Wild Burro Territory consists of 52,570 acres of National Forest System land on the northwestern portion of the Toquima mountain range. It occurs within the Toquima Management Area of the forest plan. The territory is adjoined by the Bureau of Land Management’s Hickison Herd Management Area (57,275 acres). The decision for this project would not alter management in the Hickison Herd Management Area. However, this project is designed to facilitate management of the Hickison wild burro herd as part of a larger biological unit or complex. This project will facilitate the cooperation and coordination of management efforts between the Forest Service and Bureau of Land Management personnel of the wild burro herd that utilizes both the herd management area and wild burro territory. This herd complex is also referred to as the Hickison Wild Burro Joint Management Area.
Topography primarily consists of alluvial fans broken occasionally by ridges or foothills. Climate is generally of the dry steppe (an intermediate between desert and humid climates) that supports short or scrubby vegetation. Elevation ranges from 6,000 to 7,000 feet. Average annual precipitation is 6 to 10 inches. Average winter temperatures range from 20 to 40 degrees Fahrenheit and summer temperatures range from 65 to 80 degrees Fahrenheit. Small hot springs adjoin the territory; cold water sources (especially perennial sources) are scarce. Vegetation primarily consists of a desert shrub association.
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Common species include sagebrush, horsebrush, hopsage, kochia, saltbrush, greasewood, various forbs, and grasses.1
Figure 1. Hickison Wild Burro Territory project area
1 Additional background information on the Hickison Wild Burro Territory is included in appendix A of the March 2013 notice of proposed action and opportunity to comment: Hickison Wild Burro Territory appropriate management levels and management actions project, included in the planning record (USDA Forest Service 2013).
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Need for the Proposal There is a need to achieve and maintain the Hickison wild burro herd in a thriving natural ecological balance and to advance cooperative efforts with the Bureau of Land Management across the joint management area. Therefore, the purpose of this project is to establish lower and upper appropriate management levels for the wild burro territory, consistent with appropriate management levels established by the Bureau of Land Management for the herd management area. In addition, the purpose of this project is to identify population management actions to be implemented in cooperation with the Bureau of Land Management when wild burro numbers exceed or fall below the established appropriate management level range. This decision will guide revision of the 1979 territory management plan for the Hickison Wild Burro Territory (USDA Forest Service 1979).
Consideration of desired and existing conditions and applicable law, regulation, agency policy, and land management direction creates several “needs for action” by the Forest Service at this time.
There is a need to manage the Hickison Wild Burro Territory and Herd Management Area as one biological unit (joint management area). Joint management would allow the year-round essential habitat components for wild burros (forage, water, cover and space) and unimpeded natural movement of wild burros between the wild burro territory and the herd management area. To ensure consistent management, Forest Service Manual 2261.1 requires coordination of all activities related to wild burros with the Bureau of Land Management to reflect similar management objectives (USDA Forest Service 2003; 36 CFR 222.60).
Wild burros associated with the Hickison Wild Burro Territory routinely move between the neighboring Bureau of Land Management herd management area and adjoining National Forest System lands. The wild burros spend approximately five months of the year in the Hickison Herd Management Area and the remaining time in the Hickison Wild Burro Territory and adjoining National Forest System lands. However, individuals can be found on either unit year-round.
Much of the wild burro movements among the Hickison Wild Burro Territory and the neighboring Hickison Herd Management Area can be attributed to seasonal availability of water and forage during the growing season, or relative snow depths and open ground during the winter. Generally, higher elevation habitats (above 7,500 feet) typical of the Hickison Wild Burro Territory (National Forest System lands) are used during late spring, summer, and fall. During this time period, the ground is either snow-free or has shallow snow, and water and herbaceous forage are more readily available. Lower elevation habitats typical of the Hickison Herd Management Area (Bureau of Land Management lands) are occupied by wild burros during late fall through early spring due to shallow snow depths and forage availability. Consequently, habitat conditions or population control actions in the Hickison Wild Burro Territory influence wild burros in the neighboring Hickison Herd Management Area and vice versa.
There is a need to establish a lower and an upper appropriate management level. Establishing appropriate management levels would ensure wild and free-roaming burros reach and maintain the agency’s goal of preserving these animals in a thriving natural ecological balance within the established territory boundaries. The Hickison Wild Burro Territory does not currently have established appropriate management levels. Population counts of wild burros via census flights in the herd management area have shown the Hickison wild burro population has increased from 11 wild burros in 1975 to approximately 126 in 2017 (Carter 2017; see “Wild Burros-Affected Environment” section for more information on census flights and population monitoring). There is a need to establish appropriate management levels for the Hickison wild burros so management actions can address and provide for a thriving natural ecological balance along with other land uses.
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There is a need to establish population management actions so that herd sizes can be monitored and maintained within the established appropriate management level range in a manner that promotes genetic diversity of the herd. Managing wild burro populations within the appropriate management level range will increase residual forage, stimulate leader growth on browse species, increase seed production, decrease hedging, and increase vigor of the sagebrush and salt desert scrub communities. Over time, grasses would be expected to increase in production and frequency, and alleviate some of the competition for browse species between wild burros, wildlife, and livestock. Necessary population management actions include the following:
• gathering and removing burros outside the territory boundary and joint management area • establishing a lower and upper appropriate management levels as described above • removing excess animals based on the appropriate management level range, monitoring, or both • maintaining the sex ratio of the herd at particular levels • establishing a baseline on the genetic diversity of the herd • maintaining genetic diversity through periodic herd augmentation with wild burros from other herds with similar characteristics • coordinating with the Bureau of Land Management to augment the herd if numbers fall below the lower appropriate management level • conducting periodic census flights to determine herd size and distribution • administering fertility control drugs to reduce reproductive rates There is a need to comply with forest plan direction and bring these rangelands into satisfactory condition or better (USDA Forest Service 1986).2 Degraded rangeland vegetation conditions have been documented within and outside the Hickison Wild Burro Territory and on both public and private lands. Wild burros are currently roaming outside the Hickison Wild Burro Territory and onto other public and private land and contributing to adverse grazing effects in some areas. Wild burros have been sighted several miles away in Stoneberger Basin, approximately 10 miles south along the Toquima Range and approximately 10 miles across Monitor Valley towards the Monitor Range. Season-long grazing by the wild burro population, in the absence of established appropriate management levels, has contributed to resource problems, such as degraded vegetation in winter habitats for mule deer, pronghorn, greater sage- grouse, and raptors. Habitat degradation has also been recorded within greater sage-grouse lekking habitat in the Hickison Wild Burro Territory (USDA Forest Service 2013).
Table 1 summarizes the desired conditions, existing conditions, and the disparity between the two resulting in a need for action. Desired conditions are defined by the forest plan or were developed by the interdisciplinary team after consideration of applicable laws, regulations, and agency policy.
2 This project focuses on the impacts from wild burros. Although evaluated in this document as a cumulative effect, domestic livestock grazing activities and permitting will be addressed in future environmental analyses, as appropriate.
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Table 1. Hickison Wild Burro Territory Desired and Existing Conditions Attribute Desired Conditions Existing Conditions Need for Action Appropriate Territory has high and low appropriate Appropriate management level Establish appropriate management levels management level range management level ranges that are determinations have not been made. with a high and low range compatible with sustainable, cost efficient to maintain, Hickison Herd Management Area and the and in balance with other uses. joint management area that is in balance with resources and other uses. Management across Territory management is compatible Hickison Herd Management Area has Establish compatible management with that boundaries with neighboring Hickison Burro Herd established appropriate management identified in the Bureau of Land Management Area. levels, and population management Management’s final multiple use decision objectives have been identified. on the Hickison Herd Management Area. Forage utilization Forage utilization levels by wild burros Forage utilization levels by wild burros are Control wild burro numbers and monitor are consistent with the forage utilization exceeding proper use levels. forage use patterns and rangeland standards identified in the forest plan. conditions. Wild burro distribution The Hickison Joint Management Area Wild burros are ranging outside the joint Manage the burro population within the set encompasses the majority of herd’s management area in search of water and appropriate management level to minimize annual range. forage resources. ranging outside the territory by burros. Prioritize removal of burros from areas outside the joint management area. Population management Territory has approved population No established population management Establish population management actions actions management and monitoring actions. actions exist. Monitoring actions have compatible with Hickison Herd Management been established. Area final multiple use decision. Follow established actions with monitoring. Rangeland condition Rangelands in territory are in Rangelands are in unsatisfactory condition Improve rangeland condition and trend to satisfactory or better condition. and monitoring indicates rangeland health restore healthy rangelands. Rangeland health is in functioning is at risk. condition as determined by Humboldt- Toiyabe National Forest ecological condition scorecards.
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Consistency with Forest Plan Direction The Hickison Wild Burro Territory is managed under the 1986 Toiyabe forest plan. Projects on National Forest System lands are guided by the desired conditions, goals, objectives, management direction, standards, and guidelines set out in the forest plan. Key management direction from the forest plan related to wild horse and burro management is summarized below. The specialist reports provide a more detailed evaluation of forest plan consistency specific to each resource. Management Area 9 – Toquima The forest plan divides National Forest System lands in Central Nevada into five sub-units called management areas. Each management area has resource or activity goals and management standards for managing areas in particular ways under management area prescriptions. Specific standards and guidelines for management areas apply in addition to any relevant forestwide direction. The Hickison Wild Burro Territory occurs in the Toquima Management Area. Management area direction relevant to the project includes the following:
• key wildlife and fisheries habitats will be maintained and improved (p. IV-130) • noxious farm weeds will be controlled (p. IV-130) • compatibility of livestock production with other resources and activities will be emphasized (p. IV- 130) Range Management 3- Consolidate administration responsibilities where Forest lands are adjacent to public lands (p. IV-26).
4- Develop allotment management plans for all active range allotments and wild free-roaming horse and burro territories (p. IV-26).
11- Utilize Toiyabe National Forest range suitability standards (p. IV-26).
12- Strive to achieve or maintain a minimum of 60 percent ground cover on upland rangelands with the exceptions of low sagebrush types, Wyoming big sagebrush types, crested wheatgrass seedings, pinyon/juniper types, and south facing sagebrush types on granitic slopes of the Sierra Nevada (p. IV-26).
14- Conduct monitoring and evaluation in accordance with Forest Service Handbook 2209.21, Range Environmental Analysis Handbook, and the Nevada Rangeland Monitoring Handbook (p. IV-26).
15- Achieve or maintain rangeland in satisfactory condition which is defined as: (1) having a resource value rating (RVR) of 50 or above for vegetation or other features; or (2) being in a mid-succession or higher class of ecological status; and (3) having a stable or upward trend in soil and vegetation (p. IV-26- 27).
17- Update allotment and territory management plans that are not consistent with the forest plan, following the schedule found in Chapter V (p. IV-27).
20- Each allotment management plan shall present administrative and management requirements of the specific range allotment or wild free-roaming horse or burro territory. Each plan will contain sections on objectives, actions, monitoring, and evaluation (p. IV-26).
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23- Involve livestock permittees, other federal and state agencies, and interested parties in the development of allotment and territory management plans. Utilize the coordinated resource management and planning process as appropriate (p. IV-28). Wild Free-Roaming Horse and Burros 1- Manage wild free-roaming horses and burros in accordance with the Wild Free-Roaming Horse and Burro Act of 1971 (p. IV-31) (also see Consistency with Other Direction).
2- Carry out interagency agreements with the Inyo National Forest and the Bureau of Land Management (p. IV-31).
3- Involve interested federal and state agencies and other groups in the management of wild free-roaming horses and burros (p. IV-31).
4- Manage wild free-roaming horses and burros to population levels compatible with resource capabilities and requirements (p. IV-31). Riparian Areas 4- Design range and wildlife habitat improvement projects and/or silvicultural prescriptions in riparian areas to benefit riparian area-dependent resources (p. IV-42).
6- Give priority to range, wildlife habitat, and watershed improvement projects that will rehabilitate riparian areas that cannot be restored in a timely manner by other management techniques. Use fencing for protection of riparian areas only where no other viable alternative exists (p. IV-42).
15- Avoid direct and indirect support of floodplain development and new construction in wetlands wherever there is a practical alternative (p. IV-43).
16- Capitalize on opportunities to resolve and preserve the natural and beneficial values served by floodplains; and to preserve, enhance, and manage the natural and beneficial values of wetlands (p. V-43) Wildlife and Fish 3- B. Maintain 20 percent to 55 percent cover on sage-grouse range (p. IV-49).
3- D. Maintain meadows in sage-grouse range in high ecological status. Where meadows have lost their natural characteristics because of lowered water table, trampling, overgrazing, road building, or for other reasons, take measures to restore the meadows (p. IV-49).
3- E. Maintain desirable sagebrush habitat within two miles of leks (p. IV-49).
3- H. Maintain desirable sagebrush habitat on known sage-grouse wintering areas (p. IV-49).
3- J. Protect critical areas for sage-grouse brood rearing (p. IV-49).
4- Manage ecosystems containing sensitive plant and animal and threatened and endangered animal populations to maintain or increase these populations and to achieve recovery (p. IV-49).
5- Coordinate management practices which may affect threatened and endangered animal species with the U.S. Fish and Wildlife Service and California and Nevada State wildlife agencies (p. IV-50).
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6- Improve habitat for threatened or endangered species, and sensitive species that have been adversely affected by man's activity in wilderness areas (p. IV-50).
7- Apply grazing management systems aimed at improving key habitat for big game animals and fisheries. As a maximum, browse utilization by livestock or wild horses on key winter ranges will not exceed 30 percent on those areas prior to big game use (p. IV-50).
8- Minimize disturbing activities (grazing, timber, mining, etc.) on key mule deer habitat (fawning areas, winter range, riparian areas, holding areas, migration corridors, etc.) (p. IV-50).
12- Manage aspen stands at a mid-succession or higher ecological status with emphasis on improving age-class structure (p. IV-50). Greater Sage-Grouse Forest Plan Amendment #17 On September 16, 2015, the regional forester for the Intermountain Region signed the record of decision for the greater sage-grouse forest plan amendment. This decision amended the Toiyabe forest plan to include updated management direction designed to conserve, enhance and restore greater sage-grouse habitat. Direction specific to the management of wild horses and burros includes:
• GRSG-HB-DC-067-Desired Condition – In priority and general habitat management areas, wild horse and burro populations are within established appropriate management levels. • GRSG-HB-ST-068-Standard – In priority and general habitat management areas, consider adjusting appropriate management levels, consistent with applicable law, if greater sage-grouse management standards are not met due to degradation that can be at least partially be attributed to wild horse or burro populations. • GRSG-HB-ST-069-Standard – In priority and general management areas, remove wild horses and burros outside of a wild horse and burro territory. • GRSG-HB-GL-070-Guideline – In priority and general habitat, herd gathering should be prioritized when wild horse and burro populations exceed the upper limit of the established appropriate management level. • GRSG-HB-GL-071-Guideline – In priority and general habitat, wild horse and burro population levels should be managed at the lower limit of established appropriate management level ranges, as appropriate. • GRSG-HB-GL-072-Guideline – In priority and general habitat, consider exclusion of wild horse or burros immediately following emergency situation (for example, fire, floods, and drought).
Consistency with Other Direction The Wild Free-Roaming Horses and Burros Protection Act of 1971, as amended, establishes wild free- roaming horses and burros as a part of the natural system where they occur on public lands administered by the Bureau of Land Management and National Forest System lands administered by the Forest Service. The act requires management, protection, and control of these animals within designated herd areas (synonymous with territories).
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Federal regulations pertaining to management authority of wild free-roaming horses and burros on National Forest System lands are found in Management of Wild Free-Roaming Horses and Burros – 36 CFR 222, subpart B. Additional agency direction and guidance is found in Forest Service Manual 2260 – Wild Free-Roaming Horses and Burros which sets the objective to maintain wild free-roaming horse and burro populations in a thriving natural ecological balance in the areas they inhabit on national forests (Forest Service Manual 2260.2). Forest Service Manual 2260.3 establishes policy as follows:
• confine wild free-roaming horses and burros to managed horse and burro territories as established in 1971, to the extent possible • determine population levels by considering the animals’ forage and habitat requirements, wildlife, permitted livestock, and other uses recognized under the Multiple Use-Sustained Yield Act • remove excess animals from the range at the earliest opportunity Policy in Forest Service Manual 2260 also directs consultation and cooperation with organizations that may be affected or interested in providing for protection, management, determination of excess animals, and control of wild burros. Forest Service policy as described under Forest Service Manual 2261.1 further requires coordination of all wild burro activities with the Bureau of Land Management to reflect similar management objectives. When wild burros roam part of the year on National Forest System lands and part of the year on public lands administered by the Bureau of Land Management, a single complex (joint management area) plan is advised.
The August 31, 2011 interagency agreement between the Bureau of Land Management and Forest Service Washington Office regarding wild, free-roaming horses and burros provides for the transfer of funds from the Forest Service to the Bureau of Land Management for use of their facilities, equipment, contractors, and staff for the removal, transportation, preparation, maintenance, adoption, short- and long-term care, compliance checks, and titling of wild horse and burros.
Forest Service Manual 2263.11 provides guidance on development of territory management plans. One key element to the plan is the establishment of appropriate management levels. A comprehensive procedure for establishment and adjustment of appropriate management levels is described in detail in Handbook H-4700-1, Section 4.2 (USDI Bureau of Land Management 2010). Both sources were used to establish the appropriate management levels proposed under this project, as detailed in the wild burro specialist report.
Consistency of the project with other laws and direction is also evaluated and documented in the finding of no significant impact.
Public Involvement and Proposal Development The project has been listed in the Humboldt-Toiyabe National Forest schedule of proposed actions (https://www.fs.fed.us/sopa/forest-level.php?110417) since January 1, 2013. A legal notice soliciting public comment (30-day) on the proposed action was published in the Battle Mountain Bugle (the newspaper of record) on March 6, 2013. On March 5, 2013, a scoping package describing the proposed action was mailed to approximately 130 individuals, agencies and organizations, and information regarding the project was posted on the Humboldt-Toiyabe National Forest website at https://www.fs.usda.gov/project/?project=40995. We also notified or consulted with Federal, Tribal, State, and local agencies regarding the proposal (see “Tribal Consultation and Coordination” and “Agencies and Persons Consulted” sections). The responsible official discussed this proposal with Lander, Nye, and Eureka Counties. Public scoping was conducted pursuant to National Environmental Policy Act
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regulations (40 CFR 1500–1508) and was used to determine the scope of issues to be addressed and identify issues related to the proposed action. Scoping provided those interested in, or affected by, this proposal an opportunity to make their concerns known before a decision is made by the responsible official, the Austin/Tonopah district ranger. Tribal Consultation and Coordination Potentially affected Tribes, including the Duckwater Shoshone Tribe and Yomba Shoshone Tribe, were contacted and provided the scoping notice for the proposal. They had the opportunity to review the project for potential concerns, and none were identified. Identification of Issues We received 1,253 comment letters from the public and interested parties. Of these, 61 letters were unique containing substantive comments relevant to the project. All other letters were form letters (830) or duplicates (362), containing already-submitted information. The Forest Service interdisciplinary team and district ranger considered all public comments received and organized the comments into 28 concerns. These concerns, associated comments, and our response to each concern are included in the “Response to Comment” document available in the project record and on the project website.
Concerns were evaluated against the following criteria to determine its potential influence on the proposed action, alternatives and analyses:
• Has the concern been addressed by implementation of the forest plan, in a previous site-specific analysis, or through legislative action? • Can the concern be resolved through mitigation (avoiding, minimizing, reducing, or eliminating or compensating for the proposed impact) in all alternatives? • Can the concern be resolved through project design features in all alternatives? • Is the concern within the scope of and relevant to the decision being made, and does the concern pertain directly to the proposed action? We identified no significant issues or other issues that would require changes to the proposed action. However, some comments raised the issue of economic impacts and costs of the proposed action and, in particular, the costs of placing wild burros in long-term holding facilities. The environmental consequences section of this environmental assessment evaluates these costs across all alternatives. Alternative 3 was developed to evaluate and compare the costs of not placing wild burros in long-term holding facilities and implementing other population management actions not considered under the proposed action (alternative 2).
Also, based on public and internal scoping, we refined the project to omit the “reconstruction of water developments” as initially proposed in the March 2013 notice of proposed action. Instead, we determined such activities would occur under existing or separate environmental analysis, as appropriate. We consider these incremental changes to the proposed action and alternatives to be consistent with 36 CFR 220.7(b)(2)(iii).
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Proposed Action and Alternatives The following alternatives were considered and are analyzed in the environmental analysis. Alternatives 2 and 3 were designed in accordance with the 1986 forest plan and other applicable laws and policy. A description of management direction applicable to wild horse and burro management, and the project’s compliance with that direction and other laws and regulations, is summarized elsewhere in this environmental assessment and in the project record. Alternatives Considered in Detail
Alternative 1—No Action A no-action alternative provides a baseline against which impacts of the proposed action can be measured and compared. The no-action alternative would continue the current management of the Hickison Wild Burro Territory on National Forest System lands, as described in the 1979 territory management plan (USDA Forest Service 1979). No appropriate management levels would be established, and no gathers would occur on National Forest System lands. The population of the wild burros would be allowed to grow, with the exception of gathers conducted by Bureau of Land Management in the adjoining Hickison Herd Management Area or gathers to remove nuisance wild burros from private lands and along the State highway rights-of-way outside the territory.
Other existing activities, including permitted livestock grazing, would continue to occur, and new independent actions could be analyzed and implemented under separate environmental analysis. Based on the need statement (see the “Need for the Proposal” section), the selection and implementation of the no- action alternative would not address the need to establish population management actions so that herd sizes can be monitored and maintained within the established appropriate management level range; and would not address the need to comply with current forest plan direction.
Alternative 2—Proposed Action The objective of the proposed action is to maintain the wild burro population associated with the Hickison Wild Burro Territory in a thriving natural ecological balance. The proposed action would:
• establish lower and upper appropriate management levels (16 to 45 adult wild burros) for the Hickison Wild Burro Territory; • authorize population management actions; and • approve an adaptive management process based on monitoring. Each of these actions are described in detail below. The proposed appropriate management level range, population management actions, and standard operating procedures would be used to prepare a territory management plan for the Hickison Wild Burro Territory. The new territory management plan would guide management of the territory as part of a larger biological unit as expressed by the administratively designated joint management area identified in this action. A combined appropriate management level for the joint management area would be the foundation for future management and achievement of a thriving natural ecological balance to promote a healthy, self-sustaining wild burro population. Implementation including preparation of the territory management plan would begin as early as summer of 2018.
Although one of the purposes of this project is to align management of the Forest Service’s Hickison Wild Burro Territory with the Bureau of Land Management’s Hickison Herd Management Area, this is not a
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joint analysis with the Bureau of Land Management. None of the elements of the proposed action would alter or control Bureau of Land Management actions in the herd management area.
Appropriate Management Levels Under the proposed action, the lower and upper appropriate management levels for the Hickison Wild Burro Territory would be set at 16 and 45 adult burros, respectively, for seven months of each year. The majority of the herd occupies the wild burro territory during the late spring, summer and fall. Bureau of Land Management personnel have established low and high appropriate management levels for the adjacent Hickison Herd Management Area at 16 and 45 wild burros for five months. Burros typically use the herd management area during the late fall, winter, and early spring. Therefore, harmonizing the appropriate management levels between the Hickison Burro Wild Burro Territory and the herd management area would allow the areas to be managed as a joint management area that would have a year-round capacity of 16 to 45 animals for 12 months. Accordingly, the wild burro herd that inhabits the joint management area would be managed for a minimum population of 16 adults and a maximum population of 45 adults. The process used to determine the proposed appropriate management levels is described in detail in appendix A of the wild burro specialist report.
Population Management Actions The proposed action would authorize the Austin/Tonopah District Ranger or his or her delegate or agent to remove, relocate, or both any excess wild burros in the Hickison Wild Burro Territory or adjacent National Forest System lands. It would also authorize herd augmentation in coordination with the Bureau of Land Management if the herd falls below the lower appropriate management level. To ensure the safe and humane treatment of wild burros, gathers and handling would be conducted by authorized Forest Service personnel, Bureau of Land Management personnel, or both or authorized contractors using standard operating procedures outlined in Bureau of Land Management IM-2015-151, Comprehensive Animal Welfare Program for Wild Horse and Burro Gathers (USDI Bureau of Land Management 2015a). Examples of standard operating procedures are also included in the project record.
Gather and Remove Whenever Outside of Territory When outside the territory, animals would be gathered and removed if the Hickison wild burro herd population is over the mid appropriate management level (30 adults) or gathered and returned to the territory if the herd population is under the mid appropriate management level. Like the no-action alternative, nuisance animals on private and other lands outside the joint management area, including those causing a public safety hazard, would continue to be removed with the landowners’ authorization, regardless of herd population size. This approach emphasizes the removal of animals conditioned to using areas outside the territory, and considers the potential influence of herd size on animal distribution and behavior.
Gather and Remove When Upper Appropriate Management Level is Exceeded Animals would be gathered and removed when the Hickison wild burro herd population exceeds the upper appropriate management level (45 adults). As noted above in the “Need for the Proposal” section, there are currently approximately 126 burros in the area, nearly three times the proposed upper appropriate management level. Should the proposed action be approved, an initial removal of 81 to 110 excess animals to comply with the appropriate management level range should reduce the population pressure that promotes migration beyond the territory boundary. Burros would typically be gathered via bait trapping, but helicopters would be allowed to assist during gathers if bait trapping is not effective. Gathers would be used as opportunities to manage for a natural sex ratio of one male to one female.
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Coordinate Augmentation with the Bureau of Land Management if the Herd Falls below the Lower Appropriate Management Level Humboldt-Toiyabe National Forest personnel will coordinate with Bureau of Land Management personnel to augment the herd if numbers fall below the lower appropriate management level. To promote genetic diversity, wild burros from a different herd would be released into the Hickison wild burro herd. One or two young jennies (female burros) from herds living in similar environmental conditions would be introduced from outside the joint management area. The introduced animals would not be selected to promote particular physical characteristics in the herd’s offspring.
Adaptive Management Adjustments and Design Features Alternative 2 also includes adaptive management adjustments based on monitoring results (see the “Adaptive Management Adjustments Based on Monitoring for All Action Alternatives” section); and design features for avoiding and minimizing impacts to forest resources (see the “Design Features Common to All Action Alternatives” section).
Alternative 3 Alternative 3 was developed in response to the issue of potential costs associated with the proposed action. This alternative would reduce the Hickison Wild Burro Territory population to appropriate levels without placing wild burros in long-term holding facilities. A variety of population management actions would be used, depending on whether the wild burros are inside or outside the Hickison Wild Burro Territory. These methods would also be used to maintain the wild burro herd population within the proposed appropriate management levels. Similar to the proposed action, alternative 3 would:
• establish lower and upper appropriate management levels (16 to 45 adult wild burros) for the Hickison Wild Burro Territory; • authorize population management actions; and • approve an adaptive management process based on monitoring. Each of these actions are described in detail below. The proposed appropriate management level range, population management actions, and standard operating procedures would be used to prepare a territory management plan for the Hickison Wild Burro Territory. The new territory management plan would guide management of the territory as part of a larger biological unit as expressed by the administratively designated joint management. A combined appropriate management level of 16 to 45 adult wild burros for the joint management area would be the foundation for future management and achievement of a thriving natural ecological balance to promote a healthy, self-sustaining wild burro population. Implementation, including preparation of the territory management plan, would begin as early as summer of 2018.
Although one of the purposes of this project is to align management of the Forest Service’s Hickison Wild Burro Territory with the Bureau of Land Management’s Hickison Herd Management Area, this is not a joint analysis with the Bureau of Land Management. As noted earlier, none of the elements of the proposed action would alter or control Bureau of Land Management actions in the herd management area.
Appropriate Management Levels Alternative 3 would establish the same appropriate management levels as the proposed action (alternative 2). As noted earlier, the process used to determine the proposed appropriate management level levels is described in detail in appendix A of the wild burro specialist report.
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Population Management Actions Alternative 3 would authorize the Austin/Tonopah district ranger or his or her delegate to manage the wild burro population by administering fertility control vaccines, adopting out, and sterilizing wild burros located in the Hickison Wild Burro Territory, adjacent National Forest System lands, other public lands, or nearby private lands where the wild burros have strayed and authorization to remove is given by the landowner. It would also authorize herd augmentation in coordination with Bureau of Land Management personnel if the herd population falls below the lower appropriate management level. To ensure the safe and humane treatment of wild burros, gathers and handling would be conducted by authorized Forest Service personnel, Bureau of Land Management personnel, or both or authorized contractors using standard operating procedures outlined in Bureau of Land Management IM-2015-151, Comprehensive Animal Welfare Program for Wild Horse and Burro Gathers (USDI Bureau of Land Management 2015a). Examples of standard operating procedures are also included in the project record.
Gather and Adopt, Sterilize and Release, or Both When Outside the Territory Under alternative 3, Forest Service personnel would gather wild burros, as described in the proposed action, whenever they are outside the Hickison Wild Burro Territory. The usual gather technique would be bait trapping. Helicopter drive trapping and helicopter-assisted roping from horseback would be allowed to assist if bait trapping is not effective. If the overall Hickison wild burro herd population exceeds the upper appropriate management level (45 adults), the gathered wild burros would be made available for adoption for a limited time (3 adoption attempts). The gathered wild burros would be held onsite or at a nearby short-term facility.
Female burros under 10 years of age would be sterilized under the following conditions:
• burro is located in short-term holding and has not been adopted after 3 adoption attempts • burro has been in short-term holding longer than 45 days These burros would be sterilized, marked by freeze brand, held for an adequate recovery period, and then returned to the Hickison Joint Management Area. If the animal is older than 10 years, it would be immediately made available for sale, consistent with law, regulations, and policy.
Catch, Treat, and Release When Upper Appropriate Management Level is Exceeded This alternative takes an opportunistic approach to managing wild burros within the Hickison Wild Burro Territory. Rather than conduct routine gathers of the wild burros, jennies (female burros) under this alternative would be administered the fertility control vaccine porcine zona pellucida (PZP) or PZP-22, or a combination of the two as opportunities arise. Wild burros would either be bait trapped, treated with the vaccine by jab stick and released, or approached on foot and darted with a vaccine dose using a dart rifle. Another fertility control vaccine, GonaCon (a GnRH vaccine), may be considered in the future. The effects of utilizing that vaccine would be analyzed in a supplemental environmental analysis prior to its use.
Coordinate Augmentation with the Bureau of Land Management if Herd Falls Below the Lower Appropriate Management Level As with alternative 2, Humboldt-Toiyabe National Forest personnel will coordinate with Bureau of Land Management personnel to augment the herd if numbers fall below the lower appropriate management level. To promote genetic diversity, wild burros from a different herd would be released into the Hickison wild burro herd. One or two young jennies from herds living in similar environmental conditions would
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be introduced from outside the joint management area. The introduced animals would not be selected to promote particular physical characteristics in the herd’s offspring.
Adaptive Management Adjustments and Design Features Alternative 3 includes adaptive management adjustments based on monitoring results (“Adaptive Management Adjustments Based on Monitoring for All Action Alternatives” and “Adaptive Management Adjustments Based on Population Monitoring for Alternative 3 Only” sections); and design features for avoiding and minimizing impacts to forest resources (“Design Features Common to All Action Alternatives” section). Adaptive Management Adjustments Based on Monitoring for All Action Alternatives Forest Service National Environmental Policy Act procedures provide for an “adaptive management strategy allowing for adjustment of the action during implementation.” (Forest Service Handbook 1905.15, 14.1) Under 36 CFR 220.5(e)(2) and section 220.7(b)(2)(iv):
“An adaptive management proposal or alternative must clearly identify the adjustment(s) that may be made when monitoring during project implementation indicates that the action is not having its intended effect, or is causing unintended and undesirable effects. The EIS [or EA] must disclose not only the effects of the proposed action or alternative but also the effect of the adjustment. Such proposal or alternative must also describe the monitoring that would take place to inform the responsible official during implementation whether the action is having its intended effect.”
As described below, short- and long-term monitoring would be conducted as part of the adaptive management process under each of the action alternatives.
Adjustments Based on Utilization Monitoring Monitoring would be conducted on residual forage before the winter cattle grazing season (December 1 to March 31) to ensure that the established appropriate management levels are compatible with resource capabilities while considering permitted livestock and other uses recognized under the Multiple Use- Sustained Yield Act. The proposed lower and upper appropriate management levels for wild burros are designed to keep residual forage utilization by wild burros at negligible to light levels before the winter cattle grazing season.
Short-term monitoring would measure forage utilization by wild burros, livestock, and wildlife after the end of the growing season and before the winter season for permitted livestock on the Hot Springs winter allotment. Utilization would be measured again at the end of the winter grazing season and prior to onset of spring plant growth. The proposed utilization levels are listed in table 2 and table 3.
Table 2. Maximum grass or forb utilization levels for wild burros in Hickison Wild Burro Territory Vegetation Type Pre-Winter Grazing Season Post-Winter Grazing Season Riparian grasses or forbs 20% 55% Upland grasses or forbs 20% 45%
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Table 3. Maximum shrub or tree utilization levels for wild burros in Hickison Wild Burro Territory Vegetation Type Pre-Winter Grazing Season Post-Winter Grazing Season Riparian shrubs or trees 5% 25% Upland shrubs or trees 5% 30%
If short-term monitoring indicates that the desired utilization levels are exceeded for three years in a row even though the upper appropriate management level has not been exceeded, adjustments to the wild burro herd size within the established appropriate management level range, adjustments to livestock utilization, or both would be considered. The ultimate effect of a change in management would depend largely on animal behaviors related to the use pattern. Usually, management changes have varying results. For example, change in stocking rate does not always produce a linear effect on vegetation use in key areas. Furthermore, it may not be the most effective tool for reaching some objectives. It would be much more effective to change the season or duration of use and maintain or even increase stocking rate. Gathers would not reduce the wild burro population below the lower appropriate management level established as part of this decision.
Adjustments Based on Changes in Plant Composition Using long-term monitoring, the Humboldt-Toiyabe National Forest personnel would measure changes in plant species composition in the project area. Recent studies in the project area indicate that desirable grass and forb species indicative of ecological function are not at desired levels. Repeated measurements at long-term monitoring sites would be used to determine whether desirable grass and forb species are increasing toward the desired levels.
Long-term monitoring would focus on the changes in the levels of squirreltail (Elymus elymoides), Indian ricegrass (Achnatherum hymenoides), needle-and-thread grass (Hesperostipa comata), Sandberg’s bluegrass (Poa secunda), winterfat (Krascheninnikovia lanata), and forbs not considered to be noxious or invasive. Desired levels of these species would be determined using the “Resource Implementation Protocol for Rapid Assessment Matrices” (matrices), an ecological scorecard developed by Humboldt- Toiyabe National Forest personnel (USDA Forest Service 2009). The matrices include measurable parameters for soil, vegetation, hydrology, and disturbance factors that indicate whether a vegetation community, and the wildlife habitat it represents, is in functioning, functioning-at-risk, or nonfunctioning condition. Desired levels (or condition) are those associated with functioning condition. Other tools, such as ecological site descriptions, could be used in addition to, or in lieu of, the matrices.
Changes in plant composition in the project would occur slowly over many years. Repeat monitoring would be conducted at intervals when changes in plant composition might be possible to detect— typically every 5 to 10 years. If the short-term monitoring indicates that desired utilization levels are not being exceeded, but long-term monitoring indicates that desired grasses and forbs listed above are not at desired levels or increasing, adjustments to herd size within the appropriate management level range would be considered.
The proposed short- and long-term monitoring sites are described in the rangeland resources specialist report, included in the project record. These sites may need to be adjusted over time if they are not representing use in the area. The process for selecting key areas described in the Nevada Rangeland Monitoring Handbook, Appendix F, “Procedures for Selecting Key Areas and Key Species,” (University of Nevada Cooperative Extension 2006), would be used to select new monitoring sites.
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Adjustments Based on Genetic Diversity Hair samples would be collected during every gather operation from any burros gathered in the vicinity of the wild burro territory. These hair samples would be used to monitor the heterozygosity (genetic diversity) of the herd. If the hair sample monitoring indicates that genetic diversity has decreased to such a degree that it threatens the long-term survival of the herd, the genetic diversity of the herd would be augmented by releasing wild burros from a different herd into the Hickison wild burro herd. One or two young jennies (female burros) from herds living in similar environmental conditions would be introduced from outside the joint management area. The introduced animals would not be selected to promote particular physical characteristics in the herd’s offspring. Adaptive Management Adjustments Based on Population Monitoring for Alternative 3 Only Population survey information would be reviewed as it comes available to determine if the population is decreasing. If population surveys do not show the wild burro herd has been reduced by about 64 percent after 5 years, gathers in and outside the joint management area would be conducted, and surgical ovariectomy would be employed on the older jennies (6 years old and older), along with administration of vaccine-type contraception on young jennies (less than 6 years old). Surgically treated animals would be held until full recovery prior to release back onto the joint management area. The gathers would be conducted as described above under the proposed action. Design Features Common to All Action Alternatives Design features are elements of the project that would be applied to avoid or minimize potential impacts from the action alternatives to forest resources. Design features are applied in conjunction with forest plan and other applicable direction.
General • No temporary or permanent roads would be constructed in the proposed project area.
Cultural Resources • In project specific areas, an archaeological survey would be conducted to identify cultural resources to meet Forest Service responsibilities under the National Historic Preservation Act. A cultural resource report of survey results and determination of significance and effect would be prepared in consultation with the Nevada State Historic Preservation Office. Standard procedures for protecting cultural resources will be followed. • Temporary facilities for gathers and handling, which would entail the construction of temporary fences, would fall under the national programmatic agreement among the Forest Service, the Advisory Council of Historic Preservation and the National Conference of State Historic Preservation Officers regarding rangeland management activities and the memorandum of understanding between the Humboldt-Toiyabe National Forest and the Nevada State Historic Preservation Office. • Potentially affected Tribes including the Duckwater Shoshone Tribe and Yomba Shoshone Tribe were contacted and provided the scoping notice for the proposal. Further coordination with Tribes will occur throughout the planning process and as appropriate during implementation.
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Sensitive Plants • Future planned activities that would be likely to concentrate wild burro use (such as placement of temporary handling facilities) would be designed to avoid known sensitive plant locations. • Future wild burro concentrating activities would not occur in potential habitat for sensitive plant species until surveys are performed. If sensitive plants are found, the population would be avoided. • All machinery used for gathering activities would be thoroughly cleaned of all soil and plant materials and inspected by a qualified Forest Service employee prior to entering the project area. • No machinery of any kind would pass through known invasive species infestations. • Any seed mix used for restoration efforts must be approved by the zone botanist or Humboldt- Toiyabe National Forest botanist.
Wildlife • Temporary holding corrals would be located outside of contiguous sagebrush habitat, preferably in previously disturbed areas (for example, roads, gravel pits) located greater than 2 miles from known active leks. • Artificial water sources used as bait traps would adhere to the bat conservation international water development standards (Taylor and Tuttle 2007) and would be designed with a lip or rim wide enough to accommodate perched raptors or passerines, a water level high enough for raptors or passerines to safely access, and properly installed escape ramps to reduce drowning and entrapment risks. • Bait stations would be placed outside healthy willow stands and other riparian areas to protect these areas from being trampled or consumed by captured wild burros. • Gather operations would include the following timing restrictions: ♦ Gather activities would be restricted to occur outside primary portions of the breeding seasons for greater sage-grouse, migratory birds, and raptors (February 15 to June 30). ♦ To minimize disturbances to nesting golden eagles, the district wildlife biologist would be contacted for any necessary avoidance measures regarding gather operations taking place in proximity to known golden eagle nest sites during the period July 1 to August 31. ♦ The district wildlife biologist would be contacted for any necessary avoidance measures regarding gather operations taking place outside the period February 15 to June 30, and during northern goshawk breeding and nesting dates (April 15 to July 31) to minimize disturbances to nesting northern goshawk.
Noxious and Invasive Weeds To reduce the potential for the introduction or spread of noxious and invasive weeds in the territory during gather operations:
• all hay brought onto National Forest System lands would be certified weed free; • all potential gather trap sites, bait trap sites, and temporary holding facilities would be inventoried for noxious weeds before construction; • all vehicles or equipment used to implement the proposed action would be free of dirt, mud, or visible plant debris before moving into the project area;
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• All gather sites, holding facilities, and camping areas on National Forest System lands would be recorded with GPS equipment and monitored for weeds during the next several years; and • as needed, control of noxious weeds and invasive species would be conducted under the 2001 Noxious Weed Management and Control Program decision notice (USDA Forest Service 2001).
Environmental Consequences This section summarizes the potential direct, indirect and cumulative impacts of the action alternatives and the no-action alternative for each impacted resource. Resources and issues that would not be impacted or only minimally impacted and were therefore not further analyzed include roadless areas, cultural resources, mineral and energy resources, and climate change.
Pursuant to 40 CFR 1500.1(b) and 1500.4, the discussions presented here are summaries of the completed analyses and form the scientific and analytical basis for the alternatives’ comparison. Additional details regarding the affected environment, conclusions about potential effects, and applicable forest plan and regulatory direction are available in specialist reports for each resource and other supporting documentation in the project record.
The project is not a major Federal action that may significantly affect the quality of the human environment. It has limited context and intensity (40 CFR 1508.27), individually or cumulatively, to the biological, physical, social, or economic components of the human environment. Therefore, an environmental impact statement was not prepared. Issues Not Analyzed in Detail The following section contains a discussion of the issues not analyzed in detail and the reasons for their categorization.
Wild Horses A single wild horse herd occurs in the Hickison Joint Management Area south of Highway 50. The wild horse herd (approximately 45 individuals) north of Highway 50 is prevented from crossing into the joint management area due to fencing along the highway.
Considering the consistency of the alternatives with the forest plan and other direction for wild horses, and because effects would be similar with respect to wild horses under the action alternatives, wild horses are not a useful issue in distinguishing between the alternatives. These considerations eliminated wild horses as an issue considered for detailed environmental analysis in this proposal.
Roadless Areas The Hickison Wild Burro Territory includes portions of the Toquima Cave Inventoried Roadless Area, the Sam’s Spring Inventoried Roadless Area, the Petes Well Inventoried Roadless Area, and the Iron Spring Inventoried Roadless Area, as identified in the Humboldt-Toiyabe National Forest’s inventoried roadless areas and the 2001 Roadless Conservation Rule (36 CFR 294) (Roadless Rule). Consistent with the forest plan and the Roadless Rule, none of the alternatives propose road construction, road reconstruction, or timber harvest activities within the Hickison Wild Burro Territory or roadless areas. There are no specific provisions in the forest plan or the Roadless Rule that govern or prohibit wild burro management in roadless areas.
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The interdisciplinary team evaluated the Hickison Wild Burro Territory Project for potential effects to the nine qualities identified as important characteristics of roadless areas, and to wilderness qualities and attributes. These evaluations are included in the project record.
The team determined alternative 1 (no action) would generally result in stable to degrading soil quality and the diversity and population of plant and animal communities, including habitat for threatened, endangered, and sensitive species. As the wild burro herd population continues to increase, the wild burros could further degrade these attributes in and outside the wild burro territory. For all other roadless characteristics (water and air resources, sources of public drinking water, primitive and semi-primitive classes of recreation, reference landscapes for research study or interpretation, landscape character and integrity, traditional cultural properties, and other locally unique characteristics), Alternative 1 would have no effect to a stable effect. The capability of each inventoried roadless area to be considered for a future wilderness area would not be altered by alternative 1.
The interdisciplinary team determined alternatives 2 and 3 would have no effect to a stable or improving effect on all 9 roadless qualities for each inventoried roadless area. Additionally, the capability of each inventoried roadless area to be considered for a future wilderness area would not be altered by these alternatives, and may be improved as a result of implementation of the project.
Considering the consistency of the alternatives with the forest plan with respect to roadless areas, their compatibility with the Roadless Rule, and the capability of the inventoried roadless areas to be considered for wilderness following implementation of any of the alternatives, roadless areas were not a useful issue in distinguishing between the alternatives. The management requirements of the alternatives would be similar with respect to each of the roadless areas. These considerations eliminated roadless areas as an issue considered for detailed environmental analysis in this proposal.
Cultural Resources Humboldt-Toiyabe National Forest personnel evaluated the impacts of proposed project activities in accordance with section 106 of the National Historic Preservation Act of 1966 (16 USC 470), as amended, and determined activities would not affect religious, cultural, archaeological sites or historic properties under any of the alternatives. Project-specific design features common to the action alternatives, such as conducting archaeological surveys in project specific areas prior to gathers, further ensure cultural resources would be protected with their implementation. The Nevada State Historic Preservation Office concurred with this determination on January 8, 2014, in compliance with the National Historic Preservation Act. Additionally, the Duckwater Shoshone Tribe and Yomba Shoshone Tribe have had the opportunity to review the project for potential concerns, and none were identified.
Considering the consistency of the alternatives with the forest plan with respect to cultural resources, the similar effects for the no-action alternative and alternatives 2 and 3, the lack of issues identified by interested parties and Tribes, and the agency’s completion of responsibilities under section 106 of the National Historic Preservation Act, cultural resources were not a useful issue in distinguishing between the alternatives. These considerations eliminated cultural resources as an issue considered for detailed environmental analysis in this proposal. A copy of the State Historic Preservation Office concurrence letter is included in the project file.
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Mineral and Energy Resources Although mineral potential exists, there are currently no active or proposed mines in the project area or vicinity. Managing the wild burro population within the proposed appropriate management levels would not affect future mineral or energy exploration or development in the project area. Therefore, mineral and energy resources are not analyzed further in this document. However, mining activities are addressed in the context of cumulative effects to resources (see the “Issues Analyzed in Detail” section).
Climate Change A project’s effects on climate change relate to carbon cycling, which includes carbon sequestration and the release of carbon dioxide and other greenhouse gases. The carbon stored in live biomass, dead plant material, and soil represents the balance between carbon dioxide absorbed from the atmosphere and its release through respiration, decomposition, and burning. In most cases, the national forest or grassland is the most appropriate scale for analyzing greenhouse gas emissions, biogenic carbon, and their effects. Analysis at a smaller scale can result in inaccurate results because the carbon balance at the local level fluctuates cyclically over time between carbon emitter and carbon sink, depending on when natural or human disturbances have occurred to affect its development.
The proposed action (alternative 2) and alternative 3, including management of the wild burro population within set appropriate management levels, are designed to maintain a thriving natural ecological balance within the Hickison Wild Burro Territory and herd management area. The project is consistent with the forest plan and other direction, including policy regarding ecological conditions and resilience to climate change. Proposed management actions will help bring rangelands into satisfactory or better condition and create more healthy and resilient vegetation communities which are viable under changing climatic conditions. In this respect, the project may have a slight beneficial effect. Existing vegetation communities would not be converted to other land uses and would be expected to continue as carbon sinks until the next disturbance event (fire, drought, disease, etc.). However, the action alternatives and the no-action alternative would not have a discernible effect (direct, indirect, or cumulative) on carbon storage or cycling at regional, continental or global levels. Therefore, climate change is not analyzed further in this document. Issues Analyzed in Detail This section provides a detailed analysis of issues associated with the proposal.
Activities Considered in the Cumulative Effects Analysis for all Alternatives The interdisciplinary team identified past, present, and reasonably foreseeable future activities that may contribute to cumulative effects in the analysis area of the Hickison Wild Burro Territory: wild burro management outside the Hickison Wild Burro Territory, livestock grazing and range developments, mineral exploration, and recreation. Cumulative effects activities or areas unique to the resource are identified in the respective sections.
Wild Burro Management outside the Hickison Wild Burro Territory The Bureau of Land Management Hickison Herd Management Area is adjacent to the Hickison Wild Burro Territory and contains 57,276 acres in the Big Smoky Valley west of the wild burro territory. This valley provides winter habitat for the wild burro herd associated with the herd management area and wild burro territory. In 2005, Bureau of Land Management staff published the Simpson Park Complex proposed multiple use decision (USDI Bureau of Land Management 2005), which established an
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appropriate management level for the herd management area of 16 to 45 wild burros for 5 months of the year, typically the winter months.
Bureau of Land Management personnel conducted a nuisance gather of 9 wild burros using bait trapping in 2014. The effort was conducted because wild burros had been venturing out of the wild burro territory and herd management area onto private lands in the Big Smoky Valley. If necessary, additional nuisance gathers may occur in the future in the herd management area or on private lands.
Grazing Allotment Management and Range Developments The Hickison Wild Burro Territory overlaps the Hot Springs winter allotment and a small portion of the Stoneberger allotment. The Hot Springs winter allotment has been used as winter range since this area was designated as part of the National Forest System in 1907. One-hundred and forty-five head of cattle are permitted on the Hot Springs winter allotment. Eighty head of cattle are permitted from October 1 to March 31, and 65 head of cattle are permitted from December 1 to May 31. Due to a variety of factors, the small portion of the Stoneberger allotment that overlaps the Hickison Wild Burro Territory receives very little use from cattle. The Hickison Wild Burro Territory is also adjacent to one Forest Service grazing allotment and four Bureau of Land Management grazing allotments.
Current grazing operations in the analysis area rely on a limited number of range developments. The Hickison Wild Burro Territory contains six water developments, a very small fence around Hunt’s (Burro) Well, and a corral at the Peterson Well. No range developments exist in the portion of the Stoneberger allotment that overlaps the wild burro territory. No new range developments are being considered for the analysis area but could be developed in the future under existing or separate environmental analysis.
Mineral Exploration The Linka Mine (tungsten) is located just outside the Humboldt-Toiyabe National Forest boundary near the Spencer Hot Springs. This mine was in production between 1941 and 1957. Tungsten was mined from three contiguous but separate areas referred to as the Linka, Conquest, and Hillside mines. Additional exploration was conducted in 1977 to 1978, when 8 diamond drill holes and 47 rotary holes were drilled.
More recently, work was conducted on the Snowdrift Claims, located in Township 15 North, Range 45 East, Section 14. In 1990, approximately 1,200 feet of new road was constructed from the end of the existing road to the mine. The existing portal was reopened by blasting and subsequent removal of loose material. The mining method was wet drilling on the vein structure. All mining was conducted underground. Reclamation activities included backfilling, recontouring, and seeding the portal and new road.
The Pete’s Summit Project, which proposed approximately 2.3 acres of disturbance from 11 drill sites and pads, construction of 4,322 feet of new temporary road, and 642 feet of overland travel, has been completed and is currently being monitored. The project was located near Rutherford Canyon in Township 17 North, Range 46 East, Sections 22 and 27.
The Hickison Wild Burro Territory contains several known tungsten deposits. A portion of the area may also contain gold and geothermal resources. The quantity and grade of the known tungsten deposits suggest that development of these deposits is unlikely at this time. Currently, no requests have been made to pursue development of tungsten, gold, or geothermal resources in the analysis area.
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Recreation Recreation activities, such as camping, hiking, and hunting, have occurred in the past and are still occurring. Historically, these activities have not been a major factor in the condition of resources across the analysis area.
The Spencer Hot Springs (located just west of the Hickison Wild Burro Territory on Bureau of Land Management land) is a popular recreation destination. This area includes three hot springs. One spring is diverted into a water trough. The other springs have natural pools formed by the hot spring water. Several dispersed camping sites exist near the springs.
The Toquima Cave is another attraction that draws recreational visitors. Located near Pete’s Summit, the cave draws visitors who want to view the rock shelter and the pictographs in the cave. A Forest Service campground is located 0.5 mile away. Campers or day visitors can use a trail from the campground to reach the cave. Usage of the campground is light. Other recreational features include the Toquima Trail and the Stoneberger Creek Trail and minimally developed trailhead facility.
No new developed recreation facilities are planned in the analysis area over the next 10 years. In the future, dispersed recreational uses, such as hiking, camping, horseback riding, all-terrain vehicle and off- highway vehicle use, and other various minor uses, may increase slightly over current levels. Hunting use is expected to remain at stable levels into the future.
Wild Burros This section discloses potential effects of each alternative to wild burro biology, habitat elements, population dynamics and sustainability, distribution, herd behavior, herd health, and grazing patterns necessary to inform a decision on appropriate management levels for wild burros, including necessary management actions to control and maintain the long-term health of the wild burro population.
Affected Environment Existing conditions related to the wild burro herd are summarized below. The wild burro specialist report describes in further detail the affected environment including wild burro population characteristics and management; herd history; and habitat conditions, trends, and needs.
History and Herd Description As noted in a Hot Springs cattle and horse winter allotment grazing plan (USDA Forest Service 1950), the Hickison wild burro population originated from trespass stock owned by a Mr. Peter Demale. The 1950 report indicated a request had been made for Demale to remove both trespass burros and horses. The burros persisted and by 1970, they were considered a wild herd and briefly addressed under the “Wildlife” section of the Hot Springs winter cattle and horse allotment management plan (USDA Forest Service 1970); file records indicate there was a population of 13 burros at that time. In compliance with the 1971 Wild Free-Roaming Horses and Burros Act, information was gathered beginning in 1971 and a comprehensive territory management plan was completed in 1979 (USDA Forest Service 1979). A total of 16 burros were thought to comprise the entire population.
The Hickison wild burro herd had stayed at low numbers (less than 20 animals) since the late 1940s (USDA Forest Service 1979). The herd appeared to be down to as few as 8 animals in 1995. Concerns regarding likely inbreeding depression and low genetic viability of the herd prompted Forest Service to request that the Bureau of Land Management supplement the herd with up to 12 burros from another herd management area (USDA Forest Service 1994). Translocation of 8 animals (5 jennies and 3 jacks)
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occurred in February 1995 from the Selenite Range Herd Area (NV0212) on the Winnemucca District (Bureau of Land Management). The population has since grown from 16 animals (low appropriate management level) to approximately 126 animals (Carter 2017) including a mix of blacks, grays, and paints (figure 2).
Figure 2. Typical color and conformity of wild burros on the Hickison Joint Management Area
Current Population and Recent Nuisance Gather Population estimates for the Hickison Joint Management Area are based on census flights of the joint management area and surrounding areas. The most recent aerial census flights were conducted in April 2017; on March 7, 2014; November 4, 2012; September 31, 2008; March 2005 (north of Highway 50); September, 2004 (Hickison Herd Management Area south of Highway 50); and February 2002 (Hickison Herd Management Area north and south of Highway 50).
In April 2017, a total of 126 adults and young were counted using the U.S. Geological Survey simultaneous double-count method (Lubow and Ransom 2007). The data has not been processed yet so information regarding burro distribution within or outside the joint management area is not yet available.
On September 15, 2014, Bureau of Land Management personnel completed a nuisance gather and removal of nine burros (6 jennies and 3 foals) from private crop lands west of the joint management area (USDI Bureau of Land Management 2014). Two foals were adopted locally, one aged jenny was sold, and the remaining six animals were transported to the off-range corral facility in Ridgecrest, California to await training and adoption through the Platero Project, an adoption placement program sponsored by The Human Society of United States (HSUS 2014).
The population aerial survey in November 2012 direct counted 77 adults and 13 foals for a total of 90 wild burros (Frolli 2012). Though statistical analysis has not been conducted, based on a direct count of 90 animals, the population at that time was assumed to be about 100 wild burros. The population aerial survey in 2008 direct counted 57 wild burros.
Seasonal Distribution On October 28, 2013, Bureau of Land Management range management specialist Anthony Bartlett observed 30 adult burros on the south end of the Bureau of Land Management Potts allotment in Monitor Valley approximately seven air miles east of the territory boundary. Following the March 2013 flight, only two burros were observed outside the territory. It is not known whether the 30 burros observed in Potts allotment had moved back into the joint management area boundary; the total number of animals that have remained outside the joint management area is unknown at this time.
Aerial census data from 1978, 1981, and 1998 to 2004 were analyzed to determine distribution patterns in the wild burro population between allotments, between land administered by Forest Service and Bureau
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of Land Management personnel, and within the Hickison Herd Management Area boundaries. Table 4 and table 5 summarize the general distribution and forage use patterns by land ownership.
Table 4. Seasonal distribution and forage use patterns on grazing allotments Allotment % Wild Burro Use Simpson Park (Bureau of Land Management) 72 (Hickison Herd Management Area North) Bureau of Land Management Kingston 28 (Hickison Herd Management Area South) Hot Springs Winter (Forest Service) 100 (Hickison Wild Burro Territory) Stoneberger (Forest Service) Occasional
Table 5. General distribution inside and outside the joint management area Hickison Joint Management Area % Wild Burro Use Inside 47 Outside 53 Total 100
Wild horse populations also occur in the area. Populations north of Highway 50 fluctuate throughout the year based on seasonal distribution throughout Simpson Park allotment. The March 2005 flight survey revealed a total of 45 wild horses at that time. The average number of horses utilizing the portion of the Hickison Joint Management Area north of Highway 50 is expected to be influenced by a combination of precipitation levels (horse distribution is influenced by an increased influx of snow at higher elevations), forage, and water availability. Wild burros are restricted to the south side of Highway 50 due to fencing. In the portion of the herd management area south of Highway 50, there is a single horse.
Wild Burro Distribution Inside and Outside Joint Management Area Boundaries In recent years, there have been more frequent sightings of burros up into Stoneberger Basin, down south along the Toquima range, and across the Monitor Valley towards the Monitor Range (Frolli 2012). As noted above, 30 adults were observed October 2013 in Monitor Valley north of Potts Ranch and seven miles east of the joint management area boundary.
Aerial survey data confirms wild burros have been located in areas outside the joint management area boundaries during the past ten years. The availability of forage, water, and spatial resources strongly influence the movement of wild burros within the Hickison Joint Management Area boundaries. Table 6 and table 7 illustrate the percentage of the total wild horse and burro population observed during aerial census flights inside and outside the area boundaries (USDI Bureau of Land Management 2005a).
Table 6. Wild burro distribution inside the Hickison Joint Management Area Year Simpson Park (BLM) Kingston (BLM) Forest Service September 1998 57% 9% 20% February 2002 64% 0% 22% February 2004 2% 6% 28% BLM = Bureau of Land Management
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Table 7. Wild burro distribution outside the Hickison Joint Management Area Forest Service Simpson Park BLM- Kingston (BLM- (National Forest administered lands administered lands System lands outside Year outside the JMA) outside the JMA) the JMA) September 1998 0% 0% 14% February 2002 0% 0% 14% February 2004 0% 0% 64% BLM = Bureau of Land Management; JMA = joint management area
Wild Burro Movement (USDI Bureau of Land Management 2005a) Past aerial survey, distribution flights, and ground observation provide information on wild horse and burro movement and distribution within and outside the delineated Hickison Joint Management Area boundaries. The seasonal availability of water and forage, snow cover and depths, livestock presence, and weather conditions affect the distribution of burros across the joint management area.
Burro utilization has been observed throughout the Hickison Joint Management Area. However, higher concentrations tend to exist around the foothills of Spencer Hot Springs and Pete’s Well (Joe’s Well). Extensive wild burro use has not been documented in the Kingston allotment most likely due to the lack of water resources in this area. Burro movement was restricted on a portion of the joint management area north of Highway 50 when the right-of-way fence was built in 1996.
During snow-free months, burros use areas outside the designated joint management area boundary in the vicinity of Pete’s Canyon and Clipper Gap. A greater proportion of time is spent on the Humboldt- Toiyabe National Forest during the spring, summer, and fall months near spring sources. Analysis of compiled aerial census and distribution flights, since 1989, were used to formulate generalized distribution patterns as shown in table 8. This census information is similar to assumptions from the early 1970s that the burros spend approximately 75 percent of their time on National Forest System lands and 25 percent spent on Bureau of Land Management lands.
Table 8. Annual distributions between administrative areas Management Area Agency Percent Wild Burro Use Hickison Wild Burro Territory National Forest System land 60
Hickison Herd Management Bureau of Land Management land 29 Area (Simpson Park) Hickison Herd Management Bureau of Land Management land 11 Area (Kingston)
Hickison Wild Burro Territory Habitat Suitability Determination The results of the tier one analysis, as displayed in table 9, indicate the Hickison Wild Burro Territory, as a stand-alone management unit, would not be sufficient to support healthy wild burros yearlong in a normal year or over the long term. A Bureau of Land Management rangeland health evaluation also concluded the herd management area had insufficient water and forage in most years. When managed as a territory and herd management area complex, this joint management area would have sufficient water, forage, space, and cover yearlong to support a small herd of burros. When water sources are not functional or the burro population exceeds the proposed appropriate management level, then burros seek water and forage in Stoneberger allotment east of the territory boundary and other areas on the east slope of the Toquima Range.
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Table 9. Sufficient forage, water, cover, and space yearlong Sufficient Cover and Area Sufficient Water Sufficient Forage Space Hickison Wild Burro Territory (USFS) Yes Yes No Hickison Herd Management Area (BLM) No No No Hickison Joint Management Area complex Yes Yes Yes USFS = U.S. Forest Service; BLM = Bureau of Land Management
Determination of Sustainable Forage Allocations In 2005, the Bureau of Land Management published the Simpson Park Complex proposed multiple use decision which determined existing resource conditions and assigned grazing allocations. That decision established an appropriate management level of 5 to 15 burros for 5 months on Simpson Park allotment and 11 to 30 burros for 5 months on Kingston allotment for a total of 16 to 45 wild burros for 5 months on Hickison Herd Management Area. Through this evaluation, it was concluded that standards and guidelines for rangeland health recommended by the Northeastern Great Basin Advisory Council (USDI Bureau of Land Management no date) were not fully met. RAC Standard 3 (Habitat) was not being met for riparian conditions; big game forage and browse objectives; or enhancement of sage-grouse lek, nesting, and brood-rearing areas. It also concluded that RAC Standard 5 (Healthy Wild Horse and Burro Populations for the Hickison Herd Management Area) was being partially met.
The Simpson Park decision identified the need for further data collection and analysis to evaluate rangeland health and trend and herd genetics. It stated that future adjustments to the appropriate management level would be based on habitat condition, genetic health, and distribution of burros. The appropriate management level of 16 to 45 burros allows for minimal management in conformance with the Wild Free-Roaming Horses and Burros Act.
The Hickison burro herd is thought to have an annual population increase rate of 17.5 percent. However, it is an isolated burro population with no opportunity for natural immigration from other populations; the next nearest burro population is Blue Wing and Seven Troughs, 100 air miles northwest (Winnemucca Bureau of Land Management District); Marietta Wild Burro Range 80 air miles southwest (Carson Bureau of Land Management District); or Gold Field Herd Management Area 100 air miles south (Battle Mountain Bureau of Land Management District). As mentioned above, past management in February 1995 included relocation of eight burros (5 jennies and 3 jacks) from Winnemucca District (Selenite Range Herd Area NV0212 in Pershing County). Genetic analysis of the current Hickison herd has not been conducted to date. Genetic analysis has been conducted on the Blue Wing herd (2004) and Seven Troughs herd (2008) which are approximately 25 miles east of the Selenite Range. As noted in the 2013 National Research Council report, genetic testing indicates both of those herds have heterozygosity values below the mean minus one standard deviation as compared to four domestic donkey breeds. All Bureau of Land Management burro herd management areas tested to date have low genetic diversity values when compared to Spanish and Sicilian populations (National Research Council 2013).
Condition and Trend Analysis of Rangeland Vegetation Refer to the range specialist report for rangeland condition, plant phenology, plant community composition, rangeland health and functional rating, condition and trend transects, rangeland suitability classifications, riparian ecological sites, key area utilization monitoring, authorized utilization standards, key area photo records and field observations, study plot maps, and assumptions and methodologies of rangeland analysis.
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Environmental Consequences
Alternative 1—No Action
Direct and Indirect Effects Under the no-action alternative, the wild burro population would remain above the appropriate management level and likely continue to increase over time. More hooves would result in increasing hoof action on soils around unimproved springs and stream banks, resulting in further impacts to riparian and wetland condition and water quality. Heavy to excessive utilization of forage and water resources would continue. Many of the key forage and browse species would be eliminated from the range. Areas of heavy to excessive utilization would expand as the burro herd population grows, resulting in further damage to the vegetation. Vegetation would continue to degrade until the functioning-at-risk plant communities become completely non-functional, a potentially non-repairable problem that would lead to erosion and soil loss and make the area more vulnerable to weed infestation. Eventually, long-term rangeland health would be jeopardized. In absence of healthy rangelands, animal health would eventually be impacted, either leading to increasing numbers of wild burros in poor body condition and at risk of starvation or death without human intervention or leading to increasing numbers of wild burros leaving the territory in search of forage and water resources. Wild burros venturing outside the territory could lead to a decrease in rangeland health in areas not historically grazed by the animals.
Alternative 2 - Proposed Action
Direct and Indirect Effects
Establish Appropriate Management Levels For this analysis, appropriate management level is defined as the number of adult burros (expressed as a range with an upper and lower limit) to be managed within the territory and associated herd management area together forming a joint management area. Forage for wild burros is allocated based on the appropriate management level upper limit. The appropriate management level upper limit is the maximum number of wild burros that results in a thriving natural ecological balance and avoids a deterioration of the range. This number should be somewhere below the number that would cause damage to the range (USDI Bureau of Land Management 2010).
To establish the appropriate management level upper limit, Forest Service regulations require environmental analysis of each territory to determine resource conditions, inventory of wild horse and burro populations, and coordination with other resources and activities. The appropriate management level upper limit is used to determine when there is an excess of animals on the territory which must be removed from an area in order to preserve and maintain a thriving natural ecological balance in coordination with other resources and activities (36 CFR subpart D, 222.60 (b)(3)).
As described here, the establishment of the appropriate management levels is based on planning activities which include inventory and monitoring of rangeland resources, inventory and monitoring of wild burro habitat elements, aerial and ground survey of wild burro populations, and coordination with other resource activities. The process used to determine the proposed appropriate management levels is described in detail in appendix A of the wild burro specialist report.
There would be no direct effects to wild burros from the administrative establishment of the appropriate management level range. However, management actions to meet the appropriate management level range would affect the herd and individuals, as described in the following sections. In 2017 and other past years, aerial population surveys were conducted by use of helicopter over several consecutive days. The
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helicopter staging and fueling area was located outside the territory, and support vehicles were confined to State, County, National Forest System, and Bureau of Land Management roads. Helicopter aerial surveys activities may cause noise disturbance to individual wild burros within the Hickison Joint Management Area. Any such animal may move away from that noise, freeze in position, move to hiding cover, or some combination of those actions. The animal’s reaction to helicopter noise has been similar to any other vehicle noise that might occur in the area. However, no signs of stress to individual animals have been observed. The probability of any adverse effects to any individual wild burro from ground inventory and monitoring or aerial survey is very low and well within the Federal jurisdictions to manage for wild burros.
Authorize Population Management Actions Gather and Remove when Outside the Territory Complex With the population at its current high numbers, wild burros have moved outside the territory and joint management area boundaries. These animals are free roaming in search of forage and water away from the territory and joint management area. In the past, when wild burro population numbers have been lower, the report of burros being sighted outside the territory or joint management area was uncommon. These animals are much more likely to become nuisance animals impacting private forage croplands or become a public safety concern when foraging along primary roads and highways. As these burros become habituated to forage and water sources outside the joint management area, there is a much greater likelihood of satellite herds becoming established. Generally, at population levels over the appropriate management level, wild burros persisting outside the joint management area would be determined to be excess animals that must be removed from the area in order to preserve and maintain a thriving natural ecological balance in coordination with other resources and activities as required by the act (36 CFR subpart D, 222.60 (b)(3)).
Movement of wild burros outside the territory is generally along the valley floors or edge outside the Humboldt-Toiyabe National Forest. With the exception of Stoneberger Basin during the summer months, wild burros outside the territory and extended herd management area are either on Bureau of Land Management-administered public lands and private lands or State and County road easements. There are no State or Tribal lands in the vicinity of this joint management area.
The Bureau of Land Management removed several wild burros from private lands in 2014 using water and bait traps (USDI Bureau of Land Management 2014). Analysis for that Federal action was described in the Battle Mountain District drought management environmental assessment (USDI Bureau of Land Management 2012):
“Removal of excess and drought affected animals would improve herd health and prevent widespread suffering and death of wild horses and burros. Decreased competition for remaining forage and water resources would reduce stress and promote healthier animals, as the actual population becomes balanced with available forage and water resources. Further deterioration of drought stressed rangeland and riparian resources would be avoided which would also promote range recovery (and healthy animals) over the long-term.”
There would be an effect to the individuals which is the same as that which is described in the next section. There would be no adverse effects to the overall herd health within the joint management area. It is reasonable to assume there would be decreased competition for remaining forage and water resources if these excess animals were not allowed to return to the joint management area. Direct conflict with, or damages to, private properties would be curtailed or eliminated. There may be a slightly diminished contribution to the herd’s overall genetic diversity from wild burros that have moved outside the joint management area and been gathered and removed.
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Gather and Remove when Upper Appropriate Management Level is Exceeded in the Territory Complex Implementing the proposed action would reduce the wild burro population to the appropriate management level: between 16 and 45 animals. Reducing the number of burros grazing year-round would prevent over-utilization of key forage species and promote regrowth and natural recovery of vegetation. The gather and removal of excess wild burros would decrease the potential for grazing competition between the burros and wildlife and ease grazing pressure on the remaining vegetation in the territory. Less grazing pressure would allow young vegetation to grow and develop root systems that would provide healthy plants with better resilience against future wild burro and wildlife grazing.
When wild burro numbers are at or below the upper appropriate management level, it is anticipated forage utilization levels by burros would be slight or low prior to cattle entering the allotment and territory during the winter season. It is anticipated forage utilization standards would not be exceeded by end of season when permitted cattle are removed from the allotment and the onset of annual vegetative growth begins in early spring.
With reduced year-round grazing pressure, on average, individual wild burros would have more desirable forage readily available and need to roam less in search of ample forage and water. It is anticipated overall herd health would be maintained year-round within the existing joint management area boundaries. In the past, when wild burro population numbers have been lower, the report of burros being sighted outside the territory or joint management area was uncommon. It is anticipated the remaining wild burros would be much less likely to become nuisance animals impacting private forage croplands or establish satellite herds outside the existing joint management area.
The Simpson Park multiple use decision report (USDI Bureau of Land Management 2005b) estimated the Hickison burro herd’s annual population growth rate is 17.5 percent. Under the proposed action, reproductive rates of the herd would remain moderate to high and possibly increase with an improvement in available forage, increased diet nutrition, and the absence of any fertility controls. Jennies would be less nutritionally stressed during breeding periods, gestation, or while nursing foals as compared with existing conditions. The difference between direct counts of wild burros from 1996 (20 burros observed) to 2014 (94 burros observed) is a rate of 10.16 percent over an 18-year period; however, that does not account for detectability factors.
Direct and Indirect Effects to Individual Wild Burros Gathered and Removed The following discussion outlines the impacts of specific elements of gathers on wild burros as described in the Battle Mountain District drought management environmental assessment (USDI Bureau of Land Management 2012). That document addressed general effects to both wild horses and wild burros across the Battle Mountain District which included the Hickison Herd Management Area and is applicable to wild burros within the Forest Service Hickison Wild Burro Territory of the Hickison Joint Management Area. Over the years, most operational management of Forest Service wild horse and burro gathers has been conducted by the Bureau of Land Management in conjunction with its herd management area gathers through interagency agreements. Specific relevant information about the Hickison Wild Burro Territory and joint management area has been added where appropriate.
Bait or Water Trapping - In cases where water is the most limiting factor, it may be practical to remove wild burros through water trapping. The use of hay or supplement (that is, bait) could also be used to trap animals targeted for removal due to drought conditions. Impacts of this method of removal are similar to impacts of helicopter gathers and include ground disturbance at the trap location and minor displacement of wildlife. Traps would be placed on disturbed locations, when possible, after an archeological survey has been conducted. In the case of water trapping, pens would be placed around developed rather than natural water sources, where possible, to reduce impacts to riparian areas.
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Water or bait trapping generally results in the capture of a few animals at a time and requires lengthy periods to gather larger numbers. Therefore, gather operations could be ongoing for many weeks or months to remove drought-affected animals verses gathering using a helicopter which would be accomplished in a matter of days. As a result, animals debilitated from lack of forage and water would persist for a longer time before being gathered and cared for properly.
Injuries to wild burros through bait or water trapping are similar to those described for helicopter removals. Animals would not endure the excursion from being herded several miles to a trap location but may experience injuries associated with bites and kicks while in the trap, during loading into stock trailers, and during transport to Forest Service or Bureau of Land Management preparation facilities. If foals enter the trap with adult animals, they could become injured or killed by adult wild burros fighting. Similarly, if adequate facilities did not exist to separate animals by sex or age, foals and adult animals could be injured or killed during transport in stock trailers.
Bait and water trapping would be accomplished through the gate cut method, and no wild burros would be returned to the range. The effects would be similar to those described for gate cut removals below. Various removal strategies could be employed with the use of bait or water trapping as described in the section titled “Removal Numbers”.
Helicopter Capture - Bureau of Land Management personnel have been gathering excess wild horses and burros from public lands since 1975, beginning in the Stone Cabin Wild Horse Herd Management Area, and using helicopter gather since the late 1970s. Wild burro gathers, capture, and handling will follow direction and standard operating procedures from Bureau of Land Management IM-2015-151, Comprehensive Animal Welfare Program for Wild Horse and Burro Gathers (USDI Bureau of Land Management 2015a). These procedures are utilized to reduce injury or stress to burros during gathers.
Since 2004, the Bureau of Land Management personnel in Nevada have gathered over 26,000 excess animals (horses and burros). Of these, mortality has averaged only 0.5 percent, which is very low when handling wild animals. Another 0.6 percent of the animals captured were humanely euthanized due to pre-existing conditions and in accordance with Bureau of Land Management policy. This data affirms the use of helicopters and motorized vehicles as a safe, humane, effective, and practical means for the gather and removal of excess wild horses and burros from the range. Bureau of Land Management staff is on site at all times to observe the gather, monitor animal health, and coordinate the gather activities with the contractor. As noted above, standard operating procedures based on the most current direction would be implemented to ensure the gather is conducted in a safe and humane manner and to minimize potential impact or injury to the wild burros. In their Bureau of Land Management task force report, the American Association of Equine Practitioners (2011) concluded the care, handling, and management practices utilized by the Bureau of Land Management are appropriate for this population of horses and burros and generally support the safety, health, and welfare of the animals.
Over the past 35 years, various impacts to wild horses, burros, or both from gathers have been observed. Individual, direct impacts include handling stress associated with the capture, sorting, handling, and transportation of the animals. The intensity of these impacts varies by individual and is indicated by behaviors ranging from nervous agitation to physical distress. Observations made through the completion of gathers show the majority of the wild horses captured acclimate quickly to the holding corral environment, becoming accustomed to water tanks and hay, as well as human presence. Wild burros generally exhibit less agitation and are calmer, albeit resistant to handling. The Bureau of Land Management wild horse and burro specialists and the gather contractor and crew are very attentive to the needs of all animals captured during gathers, ensuring their health and safety.
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Accidental death or the need to humanely euthanize animals as a direct result of gather activities is infrequent and averages less than one half to one percent of the animals gathered (0.5 to 1.0 percent). Injuries sustained during gathers could include nicks and scrapes to legs, face, or body from brush or tree limbs while being herded to the gather corrals by the helicopter. Rarely, wild burros could encounter barbed wire fences and could receive wire cuts. With the exception of the Highway 50 easement fence there are very few fences in proximity to the Hickison Joint Management Area. These injuries are generally not fatal and are treated with medical spray at the holding corrals until a veterinarian can examine the animal. On some gathers, injuries to horses or burros occur more frequently due to animal temperament, body condition, or both. However, on other gathers, no animals are injured or die.
Most injuries to horses and burros are sustained once the animal has been captured and occur within the gather corrals, holding corrals, or during sorting. These injuries result from kicks and bites or from collisions with corral panels or gates and are less common in burro gathers because burros tend to act less aggressively. Transport and sorting is completed as quickly and safely as possible to reduce the occurrence of fighting and then animals are moved into the large holding pens to settle in with hay and water. Injuries received during transport and sorting consist of superficial wounds of the rump, face, or legs. Occasionally, animals could sustain a spinal injury or a fractured limb which requires humane euthanasia, but these injuries are rare. Similar injuries could be sustained if wild horses or burros were captured through bait trapping, water trapping, or both, as the animals would still need to be sorted, aged, transported, and otherwise handled following their capture.
During summer gathers, environmental conditions come into play as the temperatures are higher, roads and corrals are dusty, and water is more limited on the range. During times of drought, water could be greatly limited or nearly nonexistent. Animals could have to travel long distances to find water, which may lead to dehydration or water stress. The exertion of a gather can exacerbate already debilitated conditions, leading to heat exhaustion or other complications. The helicopter pilot, regardless of season, allows wild horses and burros to travel slowly at their own pace. During gathers of drought-affected animals, the pace would be slowed to allow weak or debilitated animals to travel to the trap corrals as a group. The overall health and body condition of the Hickison wild burro herd is good with no sign of weakened conditions due to drought. If necessary, crew members may be instructed to capture the animals by roping and loading the animals into stock trailers for transport in order to reduce the stress on the animals. Extra care is taken to ensure the safe capture and recovery of jennies with foals.
Heat stress does not occur often, but if it does, death may result. If wild horses or burros are in a weakened state due to a shortage of water or forage, higher mortality could occur. In these cases, the Bureau of Land Management would take extra precautions to ensure the safe capture and post-gather care of these animals. It should be noted that burros have a higher tolerance for heat, and heat stress in the Hickison Joint Management Area would be unlikely because mean ambient temperatures are usually mild. An Animal and Plant Health Inspection Service veterinarian or other contract veterinarian would be available to examine animal condition and provide recommendations for care. Electrolytes may be added to the drinking water during summer gathers that involve animals in weakened condition. Additionally, the Battle Mountain District wild horse and burro staff maintains a supply of electrolyte paste that could be administered to affected animals as needed. Forest Service personnel and contractors would take the same precautions.
The Bureau of Land Management staff and the contractor are also proactive in controlling dust in and around the holding facility and gather corrals. These areas are sprayed down to reduce dust and limit wild horse and burro exposure to dust during summer months. Additionally, moderate travel speeds on roads reduce dust exposure during transport. The horses and burros could be sprayed in an effort to reduce
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body temperature and improve their overall comfort. In cases of extreme heat, the gather operations would be suspended once high temperatures were reached. Temperatures vary across the Battle Mountain District on a daily basis during summer months. During summer gathers, operations often conclude between noon and 2 p.m. and can be suspended earlier if the contracting officer’s representative deems it necessary to ensure animal health.
In rare cases, water toxicity or poisoning can occur when water is extremely limited or nonexistent, which can lead to cerebral edema and death. To prevent the occurrence of water poisoning, recently gathered animals may be held off full water for some time until they have time to slowly become hydrated, at which time free access to water would be provided. Similarly, hay may be fed sparingly if there is a risk of colic or other complications due to the malnourished state of recently gathered animals.
Indirect individual impacts are those impacts that occur to individual animals after the initial stress event. These impacts, like direct individual impacts, are known to occur intermittently during gather operations. An example of an indirect individual impact would be a brief skirmish among older jacks following sorting and release into the stud pen. Fighting among jack burros during gathers is less common then among stallion horses. Traumatic injuries usually do not result from these conflicts. Spontaneous abortion events among mares or jennies following capture are very rare. Observations following capture indicate the rate of miscarriage varies but can occur in about one to five percent of the captured mares, particularly if the mares are in very thin body condition or in poor health. As noted above, jennies on and outside the Hickison Joint Management Area are in good body condition.
Through the capture and sorting process, wild horses and burros are examined for health, injury, and defects. Bureau of Land Management euthanasia policy IM-2009-041 is used as a guide to determine if animals should be euthanized, and handling of animals will follow standard operating procedures outlined in Bureau of Land Management IM-2015-151, Comprehensive Animal Welfare Program for Wild Horse and Burro Gathers (USDI Bureau of Land Management 2015a). Animals euthanized for non-gather- related reasons include the following:
• those with old injuries (for example, broken hip or leg) that have caused the animal to suffer from pain or that prevent the animal from being able to travel or maintain adequate body condition • old animals that have lived a successful life on the range but now have few teeth remaining, are in poor body condition, or are weak from old age • wild horses or burros with congenital (genetic) or serious physical defects, such as club foot or sway back • animals severely debilitated or emaciated from drought During drought situations, some gathered animals could be severely debilitated or emaciated. Following examination, the Animal and Plant Health Inspection Service veterinarian could determine the animals are unlikely to recover and should be euthanized as a humane act of mercy. Extreme drought conditions could warrant action in herd management areas and territories that are within their appropriate management level. It is the agencies’ intent to intervene during drought or other emergencies to remove wild horses and burros, if necessary, before body condition declines and animals become weak from starvation or dehydration.
Foals can sometimes be orphaned during a gather. This can occur if the dam rejects the foal; the foal becomes separated from its dam and cannot be matched up following sorting; the dam dies or must be humanely euthanized during the gather; the foal is ill or weak and needs immediate care that requires removal from the dam; or the dam does not produce enough milk to support the foal. On occasion, foals
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are gathered that were previously orphaned on the range (prior to the gather) because the dam rejected it or died. These foals are usually in poor, unthrifty condition. Every effort is made to provide appropriate care to orphaned foals. Veterinarians could administer electrolyte solutions to aid in hydration and overall health. Orphan foals could be fed milk replacer to support their nutritional needs. Orphaned foals could be placed in a foster home to receive additional care. Despite these efforts, some orphaned foals could die or be humanely euthanized as an act of mercy if the prognosis for survival is very poor.
Wild Burros Remaining or Released into the Territory and Joint Management Area - Following a wild burro gather, deterioration of the range associated with wild burros would be reduced and rangelands would have the opportunity to recover, particularly from impacts of recent drought. Protecting rangeland resources from heavy or severe use during drought would improve sustainability and enhance resiliency so rangelands can support future generations of healthy wild burros.
Depending upon the gather objectives, some wild burros (whether escaped from capture or intentionally left undisturbed) would remain on the range following the gather. The wild burros that are not captured may be temporarily disturbed and moved to another area during gather operations. Over the last 20 years, it has been demonstrated that, with the exception of changes to wild horse or burro herd demographics, direct population-wide impacts are usually temporary and most impacts to individual wild burros disappear within hours to several days after the gather is completed. No observable effects associated would be expected within one month of release except for a heightened awareness of human presence.
Primary direct impacts to the wild burro populations related to gather activities include changes to herd population dynamics, age structure and sex ratio, and subsequent changes to growth rates and population size over time. Following is a discussion of various gather types.
Gate Cut Removals -Wild burros would be gathered and removed as encountered until removal and post- gather population objectives were achieved. No wild burros would be released so the number removed would equal the number gathered. The animals may be removed from specific portions of the territory or joint management area where resources are most limiting, leaving all animals in the remainder of the territory or joint management area.
Wild burros that are not gathered could be minimally impacted due to bait trap or helicopter activities but would otherwise be unaffected. All impacts would cease once gather operations were completed. Sex ratios and age distributions of the ungathered population would be unknown but should be comparable to the ratios observed in the gathered animals, and the impacts to the residual herd’s health and distribution are difficult to predict.
Without the ability to selectively remove animals from the range by age, substantially more wild burros could be removed under a gate cut gather.
Gate cut gathers eliminate the ability to remove wild burros based on animal health or desirable or historical characteristics, which often results in unintended impacts to the remaining herds. Animals of gentle disposition or those habituated to people are often easier to locate and capture. Therefore, they are typically the first to be removed using the gate cut method. Utilizing the gate cut method could distort the distribution within the territory or joint management area by removing all animals concentrated in areas where capture is easiest, while leaving animals in the outlying areas that are more difficult to gather (for example, areas of trees, rough terrain, or long distance from trap site). These areas are often times characterized by lesser quality habitat. In the case of drought gathers, the emphasis would be on the burros that inhabit the areas in the worst condition and with the fewest resources to sustain them. For the Hickison Joint Management Area, the emphasis is to remove wild burros outside the joint management
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area. In cases where it is feasible and appropriate, attempts would be made to gather animals equally across the territory or joint management area to avoid disproportionate removal.
Because no wild burros would be released back to the range, no adjustment to sex ratios or application of fertility control would take place. Wild burros would not be held at the holding corrals for extended lengths of time while waiting to apply fertility control, and burros would not be stressed by additional handling to apply fertility control. Fertility and foaling rates would be unaffected in the ungathered population which has an estimated rate of 17 percent per year by the Bureau of Land Management in the Simpson Park Complex evaluation (USDI Bureau of Land Management 2005a). The difference between direct counts of wild burros from 1996 (20 burros observed) to 2014 (94 burros observed) is a rate of 10.16 percent over an 18-year period; however, that does not account for detectability factors.
Removal of sufficient animals to achieve the high appropriate management level - Range impacts would be proportional to the residual wild horse and burro population. Impacts to rangeland health could be expected, primarily due to trailing and trampling of riparian areas. The level of impacts realized would vary depending on the health of the rangeland within the herd management area(s). Impacts to wild burros would be similar to those under the low appropriate management level gather option.
Under this option, the established appropriate management level would be exceeded following spring foaling. If drought conditions persisted, rangeland health and post drought recovery could be hindered by overpopulation.
As noted in appendix A of the wild burro specialist report and the Simpson Park multiple-use decision (USDI Bureau of Land Management 2005b), genetic analysis of the current Hickison herd has not been conducted, and further data collection and analysis to evaluate herd genetics is needed. Genetic analysis has been conducted on the Blue Wing herd (2004) and Seven Troughs herd (2008) which are approximately 25 miles east of the Selenite Range and origin of the 1996 translocated burros to the Hickison population. As noted in the National Academy of Sciences report, genetic testing indicates those two herds have heterozygosity values below the mean minus one standard deviation as compared to four domestic donkey breeds as presented by Cothran of Texas A&M University. Burros tested to date (in all Bureau of Land Management herd management areas) have low genetic diversity values when compared to 5 free-ranging Spanish donkey breeds studied by Aranguren-Mendez and others (National Research Council 2013).
It is not expected that genetic health would be impacted under the high appropriate management level option. There may be a slightly diminished contribution to the herd’s overall genetic diversity from wild burros that have moved outside the joint management area and been gathered and removed. As presented by Singer and Zeigenfuss (2000), most wild horse herds sampled have high genetic heterozygosity, genetic resources are lost slowly over periods of many generations, and wild horses are long-lived with long generation intervals. As discussed in the National Academy of Sciences report (National Research Council 2013), without monitoring and occasional genetic restoration using translocation, we would expect a similar effect to this Hickison burro population. Given the herd is isolated, any removal of breeding adults may reduce the standing genetic diversity of the population over time (100 years or more), resulting in lower individual fitness.
Removal of sufficient numbers of animals to achieve the low range of appropriate management level - Under this strategy, sufficient numbers of wild burros would be removed to achieve the low range of the appropriate management level. This strategy is consistent with most gathers conducted throughout the Bureau of Land Management’s Battle Mountain District, where excess wild horses are removed to the low appropriate management level and through the following years, the population is allowed to increase
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to the high appropriate management level at which time another gather is scheduled. Most Bureau of Land Management herd management areas in the Battle Mountain District have had gathers completed in the past 10 years. The Hickison Joint Management Area has never had a gather of excess animals except for removal of 6 adults and 3 foals from private lands in September 2014.
Range impacts would be considerably less than that at the high appropriate management level. Recovery to rangelands would be expected. Impacts to rangeland health could be reversed. Trailing to, and trampling of, riparian areas and spring sources would be reduced. The level of impacts realized would vary depending on the health of the rangeland within the wild burro territory.
Under this option, the established appropriate management level would be exceeded in eight years assuming an annual population growth rate of 17 percent. The established appropriate management level would not be exceeded for 12 years or more if population growth rates could be managed to 10 percent or less.
With improved rangeland conditions, remaining individual burros would have opportunity for higher nutritional levels with much less energy spent on foraging. At the low appropriate management level of 16 adults plus young, the risk of extirpation due to a stochastic catastrophic environmental event or events, disease, or malicious harm by poachers would be higher than at the upper appropriate management level or higher.
Removal of breeding adults would reduce the standing genetic diversity of the population over time (100 years or more) resulting in lower individual fitness to a greater extent than management to the upper appropriate management level, and translocation of burros from other territories or herd management areas may be needed to supplement the breeding population.
Adaptive Management Adjustments Based on Monitoring
Adjustments Based on Utilization Monitoring Once population levels are within the appropriate management levels, annual forage utilization monitoring would be conducted to assess use by wild burros, livestock, and wildlife. Utilization would be measured after the end of the growing season and prior to the winter permitted livestock grazing season on Hot Springs winter allotment. Utilization would be measured again at the end of the winter grazing season and prior to onset of spring plant growth. The proposed utilization levels on key forage herbaceous species by wild burros and wildlife is 20 percent prior to the winter livestock grazing season. Selection of key areas and key species for monitoring would follow the Nevada Rangeland Monitoring Handbook (University of Nevada Cooperative Extension 2006). If utilization monitoring indicates wild burro grazing is exceeding desired use levels for three years in a row, further adjustments to the herd size within the appropriate management level range would be considered.
Adjustments Based on Changes in Plant Composition If short-term monitoring shows desired utilization levels are not being exceeded but the long-term monitoring indicates desired grasses and forbs are not increasing or at desired levels, adjustments to herd size within the appropriate management level range would be considered. It is assumed here that if this action were needed, then the population would likely need to be reduced and maintained near or at the lower appropriate management level of 16 adults with young. Therefore, this action would have the same effect as managing the wild burros to low appropriate management level.
Adjustments Based on Genetic Diversity As described in the proposed action, hair samples are collected from any burros gathered near the wild burro territory to measure and monitor the herd’s genetic diversity or observed heterozygosity (Ho).
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Observed heterozygosity values below the mean for feral populations are an indication the wild herd may have diversity issues, as described in the Bureau of Land Management Wild Horses and Burros Management Handbook (USDI Bureau of Land Management 2010). The protocol requires taking hair samples from captured burros, which is a noninvasive procedure. For DNA-based hair samples, this value is 0.66 for horses (no differentiation for burros). As noted in the National Academy of Sciences report (National Research Council 2013), when this baseline value is recalculated with repeated surveys, it will decrease as allelic diversity is lost from herds when animals die or are removed to maintain appropriate management levels. Unless there is gene flow into the herd, inbreeding is inevitable resulting in lowered genetic diversity and individual fitness. The report recommends that a more appropriate comparison of wild burro observed heterozygosity values would be to free-ranging Spanish donkey breeds studied by Aranguren-Mendez (2001). Those breeds had expected heterozygosity (He) values of 0.637 to 0.684.
As noted by the 2013 National Research Council report, wild burros have less cohesive social structure than wild horses whose harems have long-term relationships between females and their dependent offspring. There are fewer challenges to integrate novel females into a wild burro population. This Hickison wild burro herd has a management history of successfully translocating novel animals into the population. Though genetic testing has not been conducted, the herd appears healthy and currently has a robust, natural recruitment rate of 15 percent per year or more.
Translocation of several, breeding-age, individual adult females from similar environmental conditions into the population every ten years, as suggested by the literature (National Research Council 2013) would have no anticipated adverse effects to the existing herd or the individual animals released. The diversity and characteristics of the herd would be further changed, as it already has, from the homogenous black colored burros originating from Peter Demale’s stock. Translocation of adult jacks into the joint management area could result in those animals or existing jacks displacing outside the joint management area.
Territory Management Plan A territory management plan will be developed which will guide management of the territory as part of the larger joint management area. The territory management plan will identify and schedule the management actions consistent with this environmental analysis and decision. It will also identify the short- and long-term management and monitoring objectives for the Hickison wild burro herd. The goals, objectives, and desired conditions will guide management of the territory and complex over the life of the territory management plan. The plan itself is an administrative planning tool for implementing the proposed action, and as such, the direct and indirect effects of actions in the territory management plan are described in this environmental analysis.
Alternative 3
Direct and Indirect Effects
Establish Appropriate Management Levels The direct and indirect effects of this action would be the same as those described under the proposed action. As noted earlier, the process used to determine the proposed appropriate management level levels is described in detail in appendix A of the wild burro specialist report. The implementation of alternative 3 would achieve the same direct and indirect effects as alternative 2, but the process would occur on a much larger time scale and positive environmental effects (for example,., improved rangeland conditions) would
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likely take longer to achieve. Implementing alternative 3 would reduce the wild burro population to 16 to 45 animals, but over a much longer period than alternative 2.
Authorize Population Management Actions Gather, Adopt Out, or Sterilize when Outside of Territory Complex The direct and indirect effects of this action would be similar to those described under the proposed action. All adoptable burros would be prepared for adoption and be made available to the interested public. Per standard operating procedure, jack burros are gelded prior to adoptions.
For animals that could not be adopted out after three adoption attempts, consideration would be given to spaying jennies and returning both spayed females and gelded males to the territory. The Hickison wild burro population would be managed for both reproductive and non-reproductive individuals within the territory herd. Sterilization surgery of both females (ovarectomies via colpotomy) and males (castration or vasectomy) would be done by a qualified veterinarian under a controlled environment with handling facilities to assure good post-operative care and safe, effective, humane recovery of each individual before it is released back into the territory.
Behavioral Effects of Sterilization As noted in the Bureau of Land Management wild horse and burro handbook (USDI Bureau of Land Management 2010) and described by others (McDonnell 1998) regarding wild burro herd social structure:
Wild burros do not form breeding bands. There are no strong individual bonds other than jenny- foal relationships. Wild burros present themselves as single animals, all-male groups, all-female groups, jenny-foal groups, or mixed groups. All of the groups are variable, and their composition may change at any time. This loose social structure, where all animals are potential breeding partners, maximizes genetic diversity in small or dispersed burro populations.
Some of the older jacks establish a breeding territory but do not prevent other males from entering this area unless there is an estrous female present. It is common for males to roam freely throughout their habitat and breed upon encountering an estrous female. Large male groups may form in the vicinity of an estrous female, and it is normal for the jenny to have multiple breeding partners. Likewise, a solitary jenny or jennies in small groups may pass through territories held by breeding males. Subordinate nonbreeding males are more or less tolerated by the territorial breeding males as they pass through or reside in their territory. In some populations, subordinate males are allowed to breed some of the jennies within the territory of a dominate jack. Nonbreeding males may form all-male bachelor groups which may have a stable submissive alliance with territorial breeding males (McDonnell 1998).
In dispersed populations in a desert environment, breeding efficiency increases as the population densities increase. As daily temperatures increase and water availability decreases, more and more animals will gather around the remaining available water sources. These areas become important areas for maximizing breeding efficiency. This temporary or seasonal increase in population density increases the chance for males to encounter estrous females. Thus, although breeding occurs year-round, increased breeding and foaling may occur during this period of time (USDI Bureau of Land Management 2010).
When the ovaries are removed from a mare, she cannot have an estrous cycle; however, she may show signs of estrous behavior. Unpredictable results follow bilateral ovariectomy for the treatment of abnormal nymphomaniac behavior [in domestic mares] (Kobluk et al. 1995). It has been reported that 60 percent of ovariectomized mares will cease estrous behavior following surgery (Loesch and Rodgerson 2003; Vaughn 1984). Yet, the full repertoire of courtship and mating behavior has been displayed by ovariectomized mares and by anestrous mares during the nonbreeding season (Asa et al. 1980; Hooper et al. 1993; National Research Council 2013). If free-ranging ovariectomized mares also show estrous
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behavior and occasionally allow copulation, interest of the stallion may be maintained which could foster band cohesion (National Research Council 2013).
Because wild burros have this loose social structure, it is anticipated the reintroduction of individual sterilized female members back into the Hickison wild burro herd would not have any observable disruptions in the current herd’s social structure.
Catch, Treat, and Release using Contraceptive Vaccine in the Territory Complex Use of Contraception in Wild Horse and Burro Management Fertility control is a method that could be used to protect rangeland ecosystem health and to reduce the frequency of wild horse and wild burro gathers and removals. Expanding the use of population growth suppression to slow population growth rates and reduce the number of animals removed from the range is a Forest Service priority. The Wild Free-Roaming Horses and Burros Act of 1971 specifically provides for contraception and sterilization (section 3.b.1). The following literature review is intended to summarize what is known, and what is not known, about potential effects of treating wild horses and burros with porcine zona pellucida and GonaCon vaccines. As noted below, some negative consequences of vaccination are possible. Porcine zona pellucida vaccines are administered only to females. Many more of the studies cited here have focused on fertility control in horses, so considerably more data are available on them than on burros. Given similarities in reproductive physiology between horses and burros, the efficacy and safety of methods could be expected to be generally similar in the two species (National Research Council 2013).
Contraception has been shown to be a cost-effective and humane treatment to slow increases in wild horse populations or, when used with other techniques, to reduce horse population size (Bartholow 2004; de Seve and Boyles-Griffin 2013). All fertility control methods in wild animals are associated with potential risks and benefits, including effects of handling, frequency of handling, physiological effects, behavioral effects, and reduced population growth rates (Hampton et al. 2015). Contraception by itself does not remove excess horses or burros from a territory’s population, so if a wild horse or burro population is more than the appropriate management level, contraception alone would result in some continuing environmental effects of overpopulation. Successful contraception reduces future reproduction. Limiting future population increases of wild burros could limit increases in environmental damage from higher densities of burros than currently exist. Horses and burros are long lived, potentially reaching 20 years of age or more in the wild and, if the population is above appropriate management level, treated animals returned to the population may continue exerting negative environmental effects, as described in the “Rangeland Condition” section, throughout their life spans. In contrast, if animals above appropriate management level are removed when burros are gathered, that leads to an immediate decrease in the severity of ongoing detrimental environmental effects.
Successful contraception would be expected to reduce the frequency of gather activities on the environment, as well as management costs to taxpayers. Bartholow (2007) concluded the application of 2- or 3-year contraceptives to wild mares could reduce operational costs in a project area by 12 to 20 percent, or up to 30 percent, in carefully planned population management programs. He also concluded contraceptive treatment would likely reduce the number of horses that must be removed in total, with associated cost reductions in the number of adoptions and total holding costs. If applying contraception to horses or burros requires capturing and handling them, the risks and costs associated with capture and handling of horses or burros may be comparable to those of gathering for removal but with lower expected adoption and long-term holding costs. Population suppression becomes less expensive if fertility control is long lasting (Hobbs et al. 2000). Selectively applying contraception to older animals and returning them to the territory could reduce long-term holding costs for those animals, which are difficult
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to adopt, and could reduce the compensatory reproduction that often follows removals (Kirkpatrick and Turner 1991). On the other hand, selectively applying contraception to younger animals can slow the rate of genetic diversity loss – a process that tends to be slow in a long-lived animal with high levels of genetic diversity – and could reduce growth rates further by delaying the age of first parturition (Gross 2000). Although contraceptive treatments may be associated with a number of potential physiological, behavioral, demographic, and genetic effects, detailed below, those concerns do not generally outweigh the potential benefits of using contraceptive treatments in situations where it is a management goal to reduce population growth rates (Garrott and Oli 2013). The decision to use this method to reduce population growth rates must be made considering these effects, as well as the potential negative consequences of inaction, such as continued overpopulation and rangeland health degradation.
Reference in this text to any specific commercial product, process, or service, or the use of any trade, firm or corporation name is for the information and convenience of the public, and does not constitute endorsement, recommendation, or favoring by the Department of Agriculture.
Porcine Zona Pellucida (PZP) Vaccine Porcine zona pellucida vaccines have been used on dozens of horse herds by the National Park Service, U.S. Forest Service, Bureau of Land Management, and Native American Tribes, and its use is approved for free-ranging wild horse and burro herds. Taking into consideration available literature on the subject, the National Research Council concluded in their 2013 report that the porcine zona pellucida vaccine was one of the preferable available methods for contraception in wild horses and burros.
Porcine zona pellucida use can reduce or eliminate the need for gathers and removals (Turner et al. 1997). The vaccines meet most of the criteria the National Research Council (2013) used to identify promising fertility control methods, in terms of delivery method, availability, efficacy, and side effects. It has been used extensively in wild horses (National Research Council 2013) and in feral burros on Caribbean islands (Turner et al. 1996, French et al. 2017). The porcine zona pellucida vaccine is relatively inexpensive, meets Bureau of Land Management requirements for safety to mares and the environment, and is produced as ZonaStat-H, an EPA-registered commercial product (EPA 2012, SCC 2015) or as PZP- 22, which is a formulation of porcine zona pellucida in polymer pellets that can lead to a longer immune response (Turner et al. 2002, Rutberg et al. 2017). ‘Native’ porcine zona pellucida proteins can be purified from pig ovaries (Liu et al. 1989). Recombinant zona pellucida proteins may be produced with molecular techniques (Gupta and Minhas 2017, Joonè et al. 2017a). It can easily be remotely administered in the field in cases where mares or jennies are relatively approachable.
Under this alternative, the Forest Service would return to the territory as needed to reapply PZP-22, ZonaStat-H, or both and initiate new treatments in order to maintain contraceptive effectiveness in controlling population growth rates. Both forms of porcine zona pellucida can safely be reapplied as necessary to control the population growth rate. Even with repeated booster treatments of porcine zona pellucida, it is expected most jennies would return to fertility, though some jennies treated repeatedly may not (see “Porcine Zona Pellucida Direct Effects” below). Once the population is at the appropriate management level and population growth seems to be stabilized, the Forest Service could use population planning software (WinEquus II, currently in development by the U.S. Geological Survey, Fort Collins Science Center) to determine the required frequency of re-treating jennies with porcine zona pellucida.
Porcine Zona Pellucida Direct Effects The historically accepted hypothesis explaining the porcine zona pellucida vaccine effectiveness posits that when injected as an antigen in vaccines, it causes the mare’s immune system to produce antibodies that are specific to zona pellucida proteins on the surface of that mare’s eggs. The antibodies bind to the mare’s eggs surface proteins (Liu et al. 1989), and effectively block sperm binding and fertilization (Zoo
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Montana 2000). Because treated mares do not become pregnant but other ovarian functions remain generally continue, porcine zona pellucida can cause a mare to continue having regular estrus cycles throughout the breeding season. More recent observations support a complementary hypothesis, which posits that porcine zona pellucida vaccination causes reductions in ovary size and function (Mask et al. 2015; Joonè et al. 2017b).
Research has demonstrated that contraceptive efficacy of an injected liquid porcine zona pellucida vaccine, such as ZonaStat-H, is approximately 90 percent or more for mares treated twice in the one year (Kirkpatrick and Turner 2002; Turner et al. 2002). High contraceptive rates of 90 percent or more can be maintained in horses that are boostered annually (Kirkpatrick et al. 1992). Approximately 60 to 85 percent of mares are successfully contracepted for one year when treated simultaneously with a liquid primer and PZP-22 pellets (Rutberg et al. 2017). Application of porcine zona pellucida for fertility control would reduce fertility in a large percentage of mares for at least one year (Ransom et al. 2011). Horses treated with PZP-22 vaccine pellets at the same time as a primer dose may experience two years of approximately 40 to 50 percent reduced foaling rates, compared to untreated animals (Rutberg et al. 2017).
The fraction of mares treated in a herd can have a large effect on the realized change in growth rate due to porcine zona pellucida contraception, with an extremely high portion of mares required to be treated to prevent population-level growth (Kirkpatrick and Turner 2002). Gather efficiency would likely not exceed 85 percent via helicopter and may be less with bait and water trapping, so the uncaptured female population would not be treated in any given year. Additionally, some animals may not respond to the fertility control vaccine but instead will continue to foal normally.
Reversibility and Effects on Ovaries In most cases, porcine zona pellucida contraception appears to be temporary and reversible, with most treated mares returning to fertility over time (Kirkpatrick and Turner 2002). The ZonaStat-H formulation of the vaccine tends to confer only one year of efficacy per dose. Some studies have found that a porcine zona pellucida vaccine in long-lasting pellets (PZP-22) can confer multiple years of contraception (Turner et al. 2007), particularly when boostered with subsequent porcine zona pellucida vaccination (Rutberg et al. 2017). Other trial data, though, indicate the pelleted vaccine may only be effective for one year (J. Turner, University of Toledo, personal communication to Paul Griffin, Bureau of Land Management wild horse and burro research coordinator).
The purpose of applying porcine zona pellucida treatment is to prevent jennies from conceiving foals, but the Forest Service acknowledges that long-term infertility or permanent sterility could be a result for some number of animals receiving the vaccinations. The rate of long-term or permanent sterility following vaccinations with porcine zona pellucida is hard to predict for individual animals, but that outcome appears to increase in likelihood as the number of doses increases (Kirkpatrick and Turner 2002). Permanent sterility for mares treated consecutively 5 to 7 years was observed by Nuñez et al. (2010, 2017). In a graduate thesis, Knight (2014) suggested repeated treatment, with as few as three to four years of porcine zona pellucida treatment, may lead to longer-term sterility and speculated sterility may result from treatment before puberty. Repeated treatment led to long-term infertility in Przewalski’s horses receiving as few as one porcine zona pellucida booster dose (Feh 2012). If some number of jennies become sterile as a result of porcine zona pellucida treatment, it would still achieve the overall goal of contraception.
In some mares, the vaccination may cause direct effects on ovaries (Gray and Cameron 2010, Joonè et al. 2017b). Joonè and others (2017a) noted reversible effects on ovaries in mares treated with one primer dose and booster dose. Bechert and others (2013) found ovarian function was affected by the SpayVac
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porcine zona pellucida vaccination, but there were no effects on other organ systems. Mask and others (2015) demonstrated equine antibodies that resulted from SpayVac immunization could bind to oocytes, zona pellucida proteins, follicular tissues, and ovarian tissues. It is possible that result is specific to the immune response to SpayVac, which may have lower porcine zona pellucida purity than ZonaStat or PZP- 22 (Hall et al. 2016). However, in studies with native zona pellucida proteins and recombinant zona pellucida proteins, Joonè and others (2017a) found transient effects on ovaries after vaccination in some treated mares; normal estrus cycling had resumed 10 months after the last treatment. SpayVac is a patented formulation of porcine zona pellucida in liposomes that can lead to multiple years of infertility (Roelle et al. 2017) but which is not reliably available for the Bureau of Land Management to use at this time. Kirkpatrick et al. (1992) noted effects on ovaries after three years of treatment with porcine zona pellucida. Observations at Assateague Island National Seashore indicate the more times a mare is consecutively treated, the longer the time lag before fertility returns, but that even mares treated for 7 consecutive years eventually returned to ovulation (Kirkpatrick and Turner 2002). Other studies have reported continued applications of porcine zona pellucida may result in decreased estrogen levels (Kirkpatrick et al. 1992) but that decrease was not biologically significant, as ovulation remained similar between treated and untreated mares (Powell and Monfort 2001). Permanent sterility for mares treated consecutively 5 to 7 years was observed by Nuñez et al. (2010, 2017). In a graduate thesis, Knight (2014) suggested repeated treatment with as few as three to four years of porcine zona pellucida treatment may lead to longer-term sterility, and sterility may result from treatment before puberty. Skinner et al. (1984) raised concerns about porcine zona pellucida effects on ovaries, based on their study in laboratory rabbits, as did Kaur and Prabha (2014), though neither paper was a study of porcine zona pellucida effects in equids.
Effects on Existing Pregnancies, Foals, and Birth Phenology Porcine zona pellucida vaccine application at the capture site does not appear to affect normal development of the fetus or foal, hormone health of the mare or behavioral responses to stallions, should the mare already be pregnant when vaccinated (Kirkpatrick and Turner 2002).
If a mare is already pregnant, the porcine zona pellucida vaccine has not been shown to affect normal development of the fetus or foal or the hormonal health of the mare with relation to pregnancy (Kirkpatrick and Turner 2003). It is possible there may be transitory effects on foals born to jennies treated with porcine zona pellucida. In mice, Sacco and others (1981) found antibodies specific to porcine zona pellucida can pass from mother mouse to pup via the placenta or colostrum but did not apparently cause any innate immune response in the offspring: the level of those antibodies were undetectable by 116 days after birth. There was no indication in that study that the fertility or ovarian function of those mouse pups was compromised nor is the Forest Service aware of any such results in horses or burros. Unsubstantiated speculative connections between porcine zona pellucida treatment and foal stealing has not been published in a peer-reviewed study and thus cannot be verified. Similarly, although Nettles (1997) noted reported stillbirths after porcine zona pellucida treatments in cynomolgus monkeys, those results have not been observed in equids despite extensive use.
On-range observations from 20 years of application to wild horses indicate porcine zona pellucida application in wild mares does not generally cause mares to give birth to foals out of season or late in the year (Kirkpatrick and Turner 2003). Nuñez’s (2010) research showed a small number of mares that had previously been treated with porcine zona pellucida foaled later than untreated mares and expressed the concern that this late foaling “may” impact foal survivorship and decrease band stability or that higher levels of attention from stallions on treated mares might harm those mares. However, that paper provided no evidence that such impacts on foal survival or mare well-being actually occurred. Rubenstein (1981) called attention to a number of unique ecological features of horse herds on Atlantic barrier islands, which
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calls into question whether inferences drawn from island herds can be applied to western wild horse herds. Ransom and others (2013), though, identified a potential shift in reproductive timing as a possible drawback to prolonged treatment with porcine zona pellucida, stating that treated mares foaled on average 31 days later than untreated mares. Results from Ransom and others (2013), however, showed over 81 percent of the documented births in this study were between March 1 and June 21; that is, within the normal spring season. Ransom and others (2013) advised that managers should consider carefully before using porcine zona pellucida in small refugia or rare species. Wild horses and burros managed by the Forest Service do not generally occur in isolated refugia nor are they rare species. Moreover, an effect of shifting birth phenology was not observed uniformly: in two of three treated wild horse populations studied by Ransom and others (2013), foaling season of treated mares extended three weeks and 3.5 months, respectively, beyond that of untreated mares. In the other population, the treated mares foaled within the same time period as the untreated mares. Furthermore, Ransom and others (2013) found no negative impacts on foal survival even with an extended birthing season. If there are shifts in birth phenology, though, it is reasonable to assume some negative effects on foal survival might result from particularly severe weather events.
Effects of Marking and Injection Standard practices for porcine zona pellucida treatment require treated animals be readily identifiable, either via brand marks or unique coloration (USDI Bureau of Land Management 2010). The Bureau of Land Management has instituted guidelines to reduce the sources of handling stress in captured animals (USDI Bureau of Land Management 2015a). The Forest Service would follow the same guidelines. Some level of transient stress is likely to result in newly captured jennies that do not have markings associated with previous fertility control treatments. It is difficult to compare that level of temporary stress with long-term stress that can result from food and water limitation on the range (Creel et al. 2013). Handling may include freeze-marking, for the purpose of identifying that jenny and identifying her porcine zona pellucida vaccine treatment history. Under past management practices, captured mares experienced increased stress levels from handling (Ashley and Holcombe 2001). Markings may also be used into the future to determine the approximate fraction of jennies that have been previously treated and could provide additional insight regarding gather efficiency.
Most jennies recover from the stress of capture and handling quickly once released back to the herd management area, and none are expected to suffer serious long-term effects from the fertility control injections, other than the direct consequence of becoming temporarily infertile. Injection site reactions associated with fertility control treatments are possible in treated mares (Roelle and Ransom 2009, Bechert et al. 2013, French et al. 2017), but swelling or local reactions at the injection site are expected to be minor in nature. Roelle and Ransom (2009) found the most time-efficient method for applying porcine zona pellucida is by hand-delivered injection of 2-year pellets when horses are gathered. They observed only two instances of swelling from that technique. Use of remotely delivered, 1-year porcine zona pellucida is generally limited to populations where individual animals can be accurately identified and repeatedly approached. The dart-delivered formulation produced injection-site reactions of varying intensity, though none of the observed reactions appeared debilitating to the animals (Roelle and Ransom 2009). Joonè and others (2017a) found injection site reactions had healed in most mares within 3 months after the booster dose, and they did not affect movement or cause fever. The longer-term nodules observed did not appear to change any animal’s range of movement or locomotor patterns and, in most cases, did not appear to differ in magnitude from naturally occurring injuries or scars.
Indirect Effects One expected long-term, indirect effect on wild horses and burros treated with fertility control would be an improvement in their overall health (Kirkpatrick and Turner 2002). Many treated jennies would not
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experience the biological stress of reproduction, foaling, and lactation as frequently as untreated jennies. The observable measure of improved health is higher body condition scores (Nuñez et al. 2010). After a treated jenny returns to fertility, her future foals would be expected to be healthier overall, and would benefit from improved nutritional quality in the jenny’s milk. This is particularly to be expected if there is an improvement in rangeland forage quality at the same time, due to reduced wild burro population size. Past application of fertility control has shown that mares’ overall health and body condition remains improved even after fertility resumes. Porcine zona pellucida treatment may increase mare survival rates, leading to longer potential lifespan (Kirkpatrick and Turner 2002, Ransom et al. 2014a). To the extent that this happens, changes in lifespan and decreased foaling rates could combine to cause changes in overall age structure in a treated herd (Kirkpatrick and Turner 2002, Roelle et al. 2010), with a greater prevalence of older mares in the herd (Gross 2000). Observations of mares treated in past gathers showed that many of the treated mares were larger than, maintained higher body condition than, and had larger healthy foals than untreated mares.
Following resumption of fertility, the proportion of jennies that conceive and foal could be increased due to their increased fitness; this has been called a ‘rebound effect.’ Elevated fertility rates have been observed after horse gathers and removals (Kirkpatrick and Turner 1991). More research is needed to document and quantify these hypothesized effects in porcine-zona-pellucida-treated herds. If repeated contraceptive treatment leads to a prolonged contraceptive effect, then that may minimize or delay the hypothesized rebound effect.
Because successful fertility control would reduce foaling rates and population growth rates, another indirect effect should be to reduce the number of wild burros that have to be removed over time to achieve and maintain the established appropriate management level. Contraception would be expected to lead to a relative increase in the fraction of older animals in the herd. Reducing the numbers of animals that would have to be removed in future gathers could allow for removal of younger, more easily adoptable excess wild burros, and could eliminate the need to send additional excess burros from this area to off-range holding corrals or pastures for long-term holding. Among jennies in the herd that remain fertile, a high level of physical health and future reproductive success would be expected because reduced population sizes should lead to more availability of water and forage resources per capita.
Reduced population growth rates and smaller population sizes could also allow for continued and increased environmental improvements to range conditions within the project area, which would have long-term benefits to wild burro habitat quality. As the population nears, or is maintained at, the level necessary to achieve a thriving natural ecological balance, vegetation resources would be expected to recover, improving the forage available to wild burros and wildlife throughout territory. With rangeland conditions more closely approaching a thriving natural ecological balance, and with a less concentrated distribution of wild burros across the territory, there should also be less trailing and concentrated use of water sources. Lower population density would be expected to lead to reduced competition among wild burros using the water sources, and less fighting among burros accessing water sources. Water quality and quantity would continue to improve to the benefit of all rangeland users including wild burros. Wild burros would also have to travel less distance back and forth between water and desirable foraging areas. Should porcine zona pellucida booster treatment continue into the future, the chronic cycle of overpopulation and large gathers and removals would no longer occur, but instead a consistent cycle of balance and stability would ensue, resulting in continued improvement of overall habitat conditions and animal health. While it is conceivable widespread and continued treatment with porcine zona pellucida could reduce the birth rates of the population to such a point that birth is consistently below mortality, that outcome is not likely unless a very high fraction of the mares present are all treated in almost every year.
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Behavioral Effects The National Research Council report (2013) noted that all fertility suppression has effects on mare behavior, mostly as a result of the lack of pregnancy and foaling, and concluded that porcine zona pellucida was a good choice for use in the program. Porcine-zona-pellucida-treated mares and jennies may continue estrus cycles throughout the breeding season which can lead to behavioral differences (as discussed below) when compared to mares and jennies that are fertile. Such behavioral differences are a potential consequence of successful contraception.
Ransom and Cade (2009) delineate behaviors that can be used to test for quantitative differences due to treatments. Ransom and others (2010) found no differences in how treated and untreated mares allocated their time between feeding, resting, travel, maintenance, and most social behaviors in three populations of wild horses, which is consistent with Powell’s (1999) findings in another population. Likewise, body condition of treated and control mares did not differ between treatment groups in the 2010 study by Ransom and others. Nuñez (2010) found treated mares had higher body condition than control mares in another population, presumably because energy expenditure was reduced by the absence of pregnancy and lactation. Knight (2014) found porcine-zona-pellucida-treated mares had better body condition, lived longer, and switched harems more frequently, while mares that foaled spent more time concentrating on grazing and lactation and had lower overall body condition. Studies on Assateague Island (Kirkpatrick and Turner 2002) showed that once fillies (female foals) born to mares treated with porcine zona pellucida during pregnancy eventually breed, they produce healthy, viable foals.
In two studies involving a total of four wild horse populations, both Nuñez and others (2009) and Ransom and others (2010) found treated mares were involved in reproductive interactions with stallions more often than control mares, which is not surprising given the evidence that treated females of other mammal species can regularly demonstrate estrus behavior while contracepted (Shumake and Killian 1997, Heilmann et al. 1998, Curtis et al. 2001). There was no evidence, though, that mare welfare was affected by the increased level of herding by stallions noted in the 2010 study by Ransom and others. Nuñez’s later analysis (2017) noted no difference in mare reproductive behavior as a function of contraception history.
Nunez (2010) stated that not all populations will respond similarly to porcine zona pellucida treatment. Differences in habitat, resource availability, and demography among conspecific populations will undoubtedly affect their physiological and behavioral responses to porcine zona pellucida contraception, and need to be considered. Kirkpatrick and others (2010) concluded:
“[T]he larger question is, even if subtle alterations in behavior may occur, this is still far better than the alternative,” and that the “…other victory for horses is that every mare prevented from being removed, by virtue of contraception, is a mare that will only be delaying her reproduction rather than being eliminated permanently from the range. This preserves herd genetics, while gathers and adoption do not.”
The National Research Council report (2013) provides a comprehensive review of the literature on the behavioral effects of contraception that put research up to that date by Nuñez and others (2009, 2010) into the broader context of all of the available scientific literature and cautions, based on its extensive review of the literature that:
“. . . in no case can the committee conclude from the published research that the behavior differences observed are due to a particular compound rather than to the fact that treated animals had no offspring during the study. That must be borne in mind particularly in interpreting long- term impacts of contraception (e.g., repeated years of reproductive “failure” due to contraception).”
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As noted in the Bureau of Land Management wild horse and burro handbook (USDI Bureau of Land Management 2010) and described by others (McDonnell 1998) regarding wild burro herd social structure:
Wild burros do not form breeding bands. There are no strong individual bonds other than jenny-foal relationships. Wild burros present themselves as single animals, all-male groups, all-female groups, jenny-foal groups, or mixed groups. All of the groups are variable, and their composition may change at any time. This loose social structure, where all animals are potential breeding partners, maximizes genetic diversity in small or dispersed burro populations.
Some of the older jacks establish a breeding territory but do not prevent other males from entering this area unless there is an estrous female present. It is common for males to roam freely throughout their habitat and breed upon encountering an estrous female. Large male groups may form in the vicinity of an estrous female, and it is normal for the jenny to have multiple breeding partners. Likewise, a solitary jenny or jennies in small groups may pass through territories held by breeding males. Subordinate nonbreeding males are more or less tolerated by the territorial breeding males as they pass through or reside in their territory. In some populations, subordinate males are allowed to breed some of the jennies within the territory of a dominate jack. Nonbreeding males may form all-male bachelor groups which may have a stable submissive alliance with territorial breeding males (McDonnell 1998).
In dispersed populations in a desert environment, breeding efficiency increases as the population densities increase. As daily temperatures increase and water availability decreases, more and more animals will gather around the remaining available water sources. These areas become important areas for maximizing breeding efficiency. This temporary or seasonal increase in population density increases the chance for males to encounter estrous females. Thus, although breeding occurs year-round, increased breeding and foaling may occur during this period of time (USDI Bureau of Land Management 2010).
Because wild burros have this loose social structure, it is anticipated the use of porcine-zona-pellucida treatments on individual jennies would not have any observable disruptions in the current herd’s social structure.
Genetic Effects of Porcine Zona Pellucida Vaccination In populations where large numbers of wild horses or burros have recent, ongoing, or both influx of breeding animals from other areas with wild or feral horses or burros, contraception is not expected to cause an unacceptable loss of genetic diversity or an unacceptable increase in the inbreeding coefficient. In any diploid population, the loss of genetic diversity through inbreeding or drift can be prevented by large effective breeding population sizes (Wright 1931) or by introducing new potential breeding animals (Mills and Allendorf 1996). The National Research Council report (2013) recommended that single herd management areas should not be considered as isolated genetic populations. Rather, managed herds of wild horses and burros should be considered as components of interacting metapopulations, with the potential for interchange of individuals and genes taking place as a result of both natural and human- facilitated movements. Introducing 1 to 2 mares every generation (about every 10 years) is a standard management technique that can alleviate potential inbreeding concerns (USDI Bureau of Land Management 2010).
In the last 10 years, there has been a high realized growth rate of wild horses and burros in most areas administered by the Bureau of Land Management and Forest Service, such that most alleles present in any given mare are likely to already be well represented in her siblings, cousins, and more distant relatives. With the exception of horses in a small number of well-known herd management areas that contain a relatively high fraction of alleles associated with old Spanish horse breeds (National Research Council 2013), the genetic composition of wild horses in lands administered by the Bureau of Land Management
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and Forest Service is consistent with admixtures from domestic breeds. As a result, in most herd management areas and territories, applying fertility control to a subset of jennies is not expected to cause irreparable loss of genetic diversity. Improved longevity and an aging population are expected results of contraceptive treatment that can provide for lengthening generation time; this result would be expected to slow the rate of genetic diversity loss (Hailer et al. 2006). Based on a population model, Gross (2000) found a strategy to preferentially treating young animals with a contraceptive led to more genetic diversity being retained than either a strategy that preferentially treats older animals or periodic gathers and removals.
Even if repeated treatment with porcine zona pellucida may lead to prolonged infertility, or even sterility in some jennies, most herd management areas have only a low risk of loss of genetic diversity if logistically realistic rates of contraception are applied. Wild burros in most herd management areas are descendants of a diverse range of ancestors coming from many breeds of domestic burros. As such, the existing genetic diversity in the majority of herd management areas does not contain unique or historically unusual genetic markers. Past interchange between herd management areas, either through natural dispersal or through assisted migration (that is, human movement of burros) means many areas are effectively indistinguishable and interchangeable in terms of their genetic composition. Roelle and Oyler- McCance (2015) used the VORTEX population model to simulate how different rates of mare sterility would influence population persistence and genetic diversity, in populations with high or low starting levels of genetic diversity, various starting population sizes, and various annual population growth rates. Their results show the risk of the loss of genetic heterozygosity is extremely low except in case where starting levels of genetic diversity are low, initial population size is 100 or less and the intrinsic population growth rate is low (5 percent per year), and very large fractions of the female population are permanently sterilized.
The Hickison wild burro herd is at risk of having low genetic diversity because of a low starting population and being geographically isolated from other burro herds. The population appeared to be down to as few as 8 animals in 1995. Concerns regarding likely inbreeding depression and low genetic viability of the herd prompted Forest Service to request that the Bureau of Land Management supplement the herd with up to 12 burros from another herd management area (USDA Forest Service 1994a). Translocation of 8 animals (5 jennies and 3 jacks) did occur in February 1995 from the Selenite Range Herd Area (NV0212), Winnemucca Bureau of Land Management District. The population has since grown from 16 animals (low appropriate management level) to well over 100 animals. Genetic analysis of the current Hickison herd has not been conducted to date, and further data collection and analysis are needed to evaluate herd genetics. Under the action alternatives, augmentation of the herd would occur if determined necessary based on genetic monitoring.
One concern that has been raised with regards to genetic diversity is treatment with immunocontraceptives could possibly lead to an evolutionary increase in the frequency of individuals whose genetic composition fosters weak immune responses (Cooper and Larson 2006, Ransom et al. 2014a). Many factors influence the strength of a vaccinated individual’s immune response, potentially including genetics, but also nutrition, body condition, and prior immune responses to pathogens or other antigens (Powers et al. 2013). This premise is based on an assumption that lack of response to porcine zona pellucida is a heritable trait, and the frequency of that trait will increase over time in a population of treated animals. Cooper and Herbert (2001) reviewed the topic, in the context of concerns about the long- term effectiveness of immunocontraceptives as a control agent for exotic species in Australia. They argue that immunocontraception could be a strong selective pressure, and selecting for reproduction in individuals with poor immune response could lead to a general decline in immune function in populations where such evolution takes place. Other authors have also speculated that differences in antibody titer
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responses could be partially due to genetic differences between animals (Curtis et al. 2001, Herbert and Trigg 2005). However, Magiafolou et al. (2003) clarify that if the variation in immune response is due to environmental factors (that is, body condition, social rank) and not due to genetic factors, there will be no expected effect of the immune phenotype on future generations. It is possible that general health, as measured by body condition, can have a causal role in determining immune response, with animals in poor condition demonstrating poor immune reactions (National Research Council 2013).
Correlations between physical factors and immune response would not preclude a heritable response to immunocontraception. In studies not directly related to immunocontraception, immune response has been shown to be heritable (Kean et al. 1994, Sarker et al. 1999). Unfortunately, predictions about the long- term, population-level evolutionary response to immunocontraceptive treatments are speculative at this point, with results likely to depend on several factors, including the strength of the genetic predisposition to not respond to porcine zona pellucida; the heritability of that gene or genes; the initial prevalence of that gene or genes; the number of females treated with a primer dose of porcine zona pellucida (which generally has a short-acting effect); the number of females treated with multiple booster doses of porcine zona pellucida; and the actual size of the genetically-interacting metapopulation of wild burros in the treatment area..
Bureau of Land Management and Forest Service personnel are not aware of any studies that have quantified the heritability of a lack of response to immunocontraception such as porcine zona pellucida vaccine or GonaCon-Equine in horses. At this point there are no studies available from which one could make conclusions about the long-term effects of sustained and widespread immunocontraception treatments on population-wide immune function. Although a few, generally isolated, feral horse populations have been treated, with high fractions of mares receiving porcine zona pellucida immunocontraception for long-term population control (for example, Assateague Island and Pryor Mountains), no studies have tested for changes in immune competence in those areas. Relative to the large number of free-roaming feral horses and burros in the western United States, immunocontraception has not been used in the type of widespread or prolonged manner that might be required to cause a detectable evolutionary response.
Although this topic requires further study, immunocontraceptives are still an effective method for stabilizing overpopulated or rapidly growing herds.
Gonadotropin Releasing Hormone (GnRH) Vaccine Registration and Safety of GonaCon-Equine The immune-contraceptive GonaCon-Equine vaccine meets most of the criteria that the National Research Council of the National Academy of Sciences (National Research Council 2013) used to identify the most promising fertility control methods in terms of delivery method, availability, efficacy, and side effects. GonaCon-Equine is approved for use by authorized Federal, State, Tribal, public and private personnel for application to wild and feral equids in the United States (EPA 2013, 2015). Its use is appropriate for free-ranging wild horse and burro herds. Taking into consideration available literature on the subject, the National Research Council concluded in their 2013 report that GonaCon-B (which is produced under the trade name GonaCon-Equine for use in feral horses and burros) was one of the most preferable available methods for contraception in wild horses and burros. GonaCon-Equine has been used on feral horses in Theodore Roosevelt National Park and on wild horses in one herd management area administered by the Bureau of Land Management (USDI Bureau of Land Management 2015b). GonaCon- Equine can be remotely administered in the field in cases where mares are relatively approachable, using a customized pneumatic dart (McCann et al. 2017). Use of remotely delivered (dart-delivered) vaccine is
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generally limited to populations where individual animals can be accurately identified and repeatedly approached within 50 meters (USDI Bureau of Land Management 2010).
As with other contraceptives, the long-term goal of GonaCon-Equine use is to reduce or eliminate the need for gathers and removals (National Research Council 2013). GonaCon-Equine vaccine is an Environmental Protection Agency-approved pesticide (EPA 2009a) that is relatively inexpensive, meets the Bureau of Land Management requirements for safety to animals and the environment, and is produced in a USDA Animal and Plant Health Inspection Service laboratory. Its categorization as a pesticide is consistent with regulatory framework for controlling overpopulated vertebrate animals, and in no way is meant to convey the vaccine is lethal; the intended effect of the vaccine is as a contraceptive. GonaCon is produced as a pharmaceutical-grade vaccine, including aseptic manufacturing technique to deliver a sterile vaccine product (Miller et al. 2013). If stored at 4 degrees Celsius, the shelf life is 6 months (Miller et al 2013).
Miller and others (2013) reviewed the vaccine environmental safety and toxicity. When advisories on the product label (EPA 2015) are followed, the product is safe for users and the environment (EPA 2009b). EPA waived a number of tests prior to registering the vaccine, because GonaCon was deemed to pose low risks to the environment if the product label is followed (Wang-Chaill et al. 2017, in press).
Under alternative 3, the Forest Service would return to the wild burro territory as needed to reapply GonaCon-Equine and initiate new treatments in order to maintain contraceptive effectiveness in controlling population growth rates. GonaCon-Equine can safely be reapplied as necessary to control the population growth rate. Even with one booster treatment of GonaCon-Equine, it is expected most, if not all, jennies would return to fertility at some point, although the average duration of effect after booster doses has not yet been quantified. The expected rate for the return to fertility rate in jennies boosted more than once with GonaCon-Equine is unknown. Once the herd size in the project area is at the appropriate management level and population growth seems to be stabilized, the Forest Service could make a determination about the required frequency of new jenny treatments and re-treatments with GonaCon, to maintain the number of burros within the appropriate management level.
GnRH Vaccine Direct Effects GonaCon-Equine is one of several vaccines that have been engineered to create an immune response to the gonadotropin releasing hormone peptide (GnRH). GnRH is a small peptide that plays an important role in signaling the production of other hormones involved in reproduction in both sexes. GnRH is highly conserved across mammalian taxa, so some inferences about the mechanism and effects of GonaCon-Equine in horses can be made from studies that used different anti-GnRH vaccines in horses and other taxa. Other anti-GnRH vaccines include Improvac (Imboden et al. 2006, Botha et al. 2008, Schulman et al. 2013, Dalmau et al. 2015), made in South Africa; Equity (Elhay et al. 2007, Janett et al. 2009a), made in Australia; Improvest, for use in swine (Bohrer et al. 2014); Repro-BLOC (Boedeker et al. 2011); and Bopriva, for use in cows (Balet et al. 2014). Of these, GonaCon-Equine, Improvac, and Equity are specifically intended for horses and burros. Other anti-GnRH vaccine formulations have also been tested but did not become trademarked products (Goodloe 1991, Dalin et al 2002, Stout et al. 2003, Donovan et al. 2013). The effectiveness and side-effects of these various anti-GnRH vaccines may not be the same as would be expected from GonaCon-Equine use in horses. Results could differ as a result of differences in the preparation of the GnRH antigen and the choice of adjuvant used to stimulate the immune response. While GonaCon-Equine can be administered as a single dose, most other anti-GnRH vaccines require a primer dose and at least one booster dose to be effective.
GonaCon has been produced by the USDA Animal and Plant Health Inspection Service (Fort Collins, Colorado) in several different formulations, the history of which is reviewed by Miller and others (2013).
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In any vaccine, the antigen is the stimulant to which the body responds by making antigen-specific antibodies. Those antibodies then signal to the body that a foreign molecule is present, initiating an immune response that removes the molecule or cell. GonaCon vaccines present the recipient with hundreds of copies of GnRH as peptides on the surface of a linked protein that is naturally antigenic because it comes from invertebrate hemocyanin (Miller et al. 2013). Early GonaCon formulations linked many copies of GnRH to a protein from the keyhole limpet (GonaCon-KHL), but more recently produced formulations where the GnRH antigen is linked to a protein from the blue mussel (GonaCon-B) proved less expensive and more effective (Miller et al. 2008). GonaCon-Equine is in the category of GonaCon-B vaccines.
Adjuvants are included in vaccines to elevate the level of immune response, inciting recruitment of lymphocytes and other immune cells which foster a long-lasting immune response specific to the antigen. For some formulations of anti-GnRH vaccines, a booster dose is required to elicit at contraceptive response, though GonaCon can cause short-term contraception in a fraction of treated animals from one dose (Powers et al. 2011, Gionfriddo et al. 2011a, Baker et al. 2013, Miller et al. 2013). Adjuvac, the adjuvant used in GonaCon, generally leads to a milder reaction than Freunds complete adjuvant (Powers et al. 2011). Adjuvac contains a small number of killed Mycobacterium avium cells (Miller et al. 2008, Miller et al. 2013). The antigen and adjuvant are emulsified in mineral oil, such that they are not all presented to the immune system right after injection; it is thought that the mineral oil emulsion leads to a depot effect and longer-lasting immune response (Miller et al. 2013). Miller and others (2008, 2013) speculated that, in cases where memory-B leukocytes are protected in immune complexes in the lymphatic system, it can lead to years of immune response. Increased doses of vaccine may lead to stronger immune reactions but only to a certain point. When Yoder and Miller (2010) tested varying doses of GonaCon in prairie dogs, antibody responses to the 200-microgram and 400-microgram doses were equal to each other but were both higher than in response to a 100-microgram dose.
The most direct result of successful GnRH vaccination is that it has the effect of decreasing the level of GnRH signaling in the body, as evidenced by a drop in leutinizing hormone levels and a cessation of ovulation. Antibody titer measurements are proximate measures of the antibody concentration in the blood specific to a given antigen. Anti-GnRH titers generally correlate with a suppressed reproduction system (Gionfriddo et al. 2011a, Powers et al. 2011). Various studies have attempted to identify a relationship between anti-GnRH titer levels and infertility, but that relationship has not been universally predictable or consistent. The time length that titer levels stay high appears to correlate with the length of suppressed reproduction (Dalin et al. 2002, Levy et al. 2011, Donovan et al. 2013, Powers et al. 2011). For example, Goodloe (1991) noted mares did produce elevated titers and had suppressed follicular development for 11 to 13 weeks after treatment, but all treated mares ovulated after the titer levels declined. Similarly, Elhay (2007) found high initial titers correlated with longer-lasting ovarian and behavioral anoestrus. However, Powers and others (2011) did not identify a threshold level of titer that was consistently indicative of suppressed reproduction despite seeing a strong correlation between antibody concentration and infertility nor did Schulman and others (2013) find a clear relationship between titer levels and mare acyclicity.
In many cases, young animals appear to have higher immune responses to, and stronger contraceptive effects from, anti-GnRH vaccines than older animals (Brown et al. 1994, Curtis et al. 2001, Stout et al. 2003, Schulman et al. 2013). Vaccinating with GonaCon at too young an age, though, may prevent effectiveness; Gionfriddo and others (2011a) observed weak effects in 3- to 4-month-old fawns. It has not been possible to predict which individuals of a given age class will have long-lasting immune responses to the GonaCon vaccine. Gray (2009) noted mares in poor body condition tended to have lower contraceptive efficacy in response to GonaCon-B. Miller et al. (2013) suggested higher parasite loads
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might have explained a lower immune response in free-roaming horses than had been observed in a captive trial. At this time, the most important factors affecting efficacy are unclear.
Females successfully contracepted by GnRH vaccination enter a state similar to anestrus, have a lack of or incomplete follicle maturation, and no ovarian cycling (Botha et al. 2008). A leading hypothesis is that anti-GnRH antibodies bind GnRH in the hypothalamus-pituitary ‘portal vessels,’ preventing GnRH from binding to GnRH-specific binding sites on gonadotroph cells in the pituitary, thereby limiting the production of gonadotropin hormones, particularly leutinizing hormone and, to a lesser degree, follicle- stimulating hormone (Powers et al. 2011, National Research Council 2013). This reduction in leutinizing hormone (and follicle-stimulating hormone), and a corresponding lack of ovulation, has been measured in response to treatment with anti-GnRH vaccines (Boedeker et al. 2011, Garza et al. 1986).
Females successfully treated with anti-GnRH vaccines have reduced progesterone levels (Garza et al 1986, Stout et al. 2003, Imboden et al. 2006, Elhay et al. 2007, Botha et al. 2008, Killian et al. 2008, Miller et al. 2008, Janett et al. 2009b, Schulman et al. 2013, Balet et al. 2014, Dalmau et al. 2015) and β- 17 estradiol levels (Elhay et al. 2007), but no great decrease in estrogen levels (Balet et al. 2014). Reductions in progesterone do not occur immediately after the primer dose but can take several weeks or months to develop (Elhay et al. 2007, Botha et al. 2008, Schulman et al. 2013, Dalmau et al. 2015). This indicates ovulation is not occurring and corpora lutea, formed from post-ovulation follicular tissue, are not being established.
Changes in hormones associated with anti-GnRH vaccination lead to measurable changes in ovarian structure and function. The volume of ovaries reduced in response to treatment (Garza et al. 1986, Dalin et al. 2002, Imboden et al. 2006, Elhay et al. 2007, Botha et al. 2008, Gionfriddo 2011a, Dalmau et al. 2015). Treatment with an anti-GnRH vaccine changes follicle development (Garza et al. 1986, Stout et al. 2003, Imboden et al. 2006, Elhay et al. 2007, Donovan et al. 2013, Powers et al. 2011, Balet et al 2014) with the result that ovulation does not occur. A related result is that the ovaries can exhibit less activity and cycle with less regularity or not at all in anti-GnRH-vaccine-treated females (Goodloe 1991, Dalin et al. 2002, Imboden et al. 2006, Elhay et al. 2007, Janett et al. 2009b, Donovan et al. 2013, Powers et al. 2011). In studies where the vaccine required a booster, this result was generally observed within several weeks after delivery of the booster dose.
GnRH Vaccine Contraceptive Effects The National Research Council (2013) review pointed out that single doses of GonaCon-Equine do not lead to high rates of initial effectiveness or long duration. Initial effectiveness of one dose of GonaCon- Equine vaccine appears to be lower than for a combined primer-plus-booster dose of the porcine zona pellucida vaccine Zonastat-H (Kirkpatrick et al. 2011), and the initial effect of a single GonaCon dose can be limited to as little as one breeding season. However, preliminary results on the effects of boostered doses of GonaCon-Equine indicate it can have high efficacy and longer-lasting effects in free-roaming horses (Baker et al. 2017) than the 1-year effect generally expected from a single booster of Zonastat-H.
GonaCon and other anti-GnRH vaccines can be injected while a female is pregnant (Miller et al. 2013, Powers et al. 2011, Baker et al. 2013). In such a case, a successfully contracepted mare will be expected to give birth during the following foaling season but to be infertile during the same year’s breeding season. Thus, a mare injected in November of 2018 would not show the contraceptive effect (that is, no new foal) until spring of 2020.
Too few studies have reported on the various formulations of anti-GnRH vaccines to make generalizations about differences between products, but GonaCon formulations were consistently good at causing loss of fertility in a statistically significant fraction of treated mares for at least one year (Killian et al. 2009, Gray
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et al. 2010, Baker et al. 2013, 2017). With few exceptions (Goodloe 1991), anti-GnRH treated mares gave birth to fewer foals in the first season when there would be an expected contraceptive effect (Botha et al. 2008, Killian et al. 2009, Gray et al. 2010, Baker et al. 2013). Goodloe (1991) used an anti-GnRH-KHL vaccine with a triple adjuvant, in some cases attempting to deliver the vaccine to horses with a hollow- tipped ‘biobullet,’ but concluded the vaccine was not an effective immunocontraceptive in that study.
Not all mares should be expected to respond to the GonaCon-equine vaccine; some number should be expected to continue to become pregnant and give birth to foals. In studies where mares were exposed to stallions, the fraction of treated mares that are effectively contracepted in the year after anti-GnRH vaccination varied from study to study, ranging from approximately 50 percent (Baker et al. 2017), to 61 percent (Gray et al. 2010) to approximately 90 percent (Killian et al. 2006, 2008, 2009). Miller and others (2013) noted lower effectiveness in free-ranging mares (Gray et al. 2010) than captive mares (Killian et al. 2009). Some of these rates are lower than the high rate of effectiveness typically reported for the first year after porcine zona pellucida vaccine treatment (Kirkpatrick et al. 2011). In the one study that tested for a difference, darts and hand-injected GonaCon doses were equally effective in terms of fertility outcome (McCann et al. 2017).
In studies where mares were not exposed to stallions, the duration of effectiveness also varied. A primer and booster dose of Equity led to anoestrus for at least 3 months (Elhay et al. 2007). A primer and booster dose of Improvac also led to loss of ovarian cycling for all mares in the short term (Imboden et al. 2006). It is worth repeating that those vaccines do not have the same formulation as GonaCon.
Results from horses (Baker et al. 2017) and other species (Curtis et al. 2001) suggest providing a booster dose of GonaCon-Equine will increase the fraction of temporarily infertile animals to higher levels than would a single vaccine dose alone.
Longer-term infertility has been observed in some mares treated with anti-GnRH vaccines, including GonaCon-Equine. In a single-dose mare captive trial with an initial year effectiveness of 94 percent, Killian and others (2008) noted infertility rates of 64 percent, 57 percent, and 43 percent in treated mares during the following three years, while control mares in those years had infertility rates of 25 percent, 12 percent, and 0 percent in those years. GonaCon effectiveness in free-roaming populations was lower, with infertility rates consistently near 60 percent for three years after a single dose in one study (Gray et al. 2010) and annual infertility rates decreasing over time from 55 percent to 30 percent to 0 percent in another study with one dose (Baker et al. 2017). Similarly, gradually increasing fertility rates were observed after single dose treatment with GonaCon in elk (Powers et al. 2011) and deer (Gionfriddo et al. 2011a).
Baker et al. (2017) observed a return to fertility over 4 years in mares treated once with GonaCon but then noted extremely low fertility rates of 0 percent and 16 percent in the two years after the same mares were given a booster dose four years after the primer dose. These are extremely promising preliminary results from that study in free-roaming horses; a third year of post-booster monitoring is ongoing in summer 2017, and researchers on that project are currently determining whether the same high-effectiveness, long-term response is observed after boosting with GonaCon after 6 months, 1 year, 2 years, or 4 years after the primer dose. Four of 9 mares treated with primer and booster doses of Improvac did not return to ovulation within 2 years of the primer dose (Imboden et al. 2006), though one should probably not make conclusions about the long-term effects of GonaCon-Equine based on results from Improvac.
It is difficult to predict which females will exhibit strong or long-term immune responses to anti-GnRH vaccines (Killian et al. 2006, Miller et al. 2008, Levy et al. 2011). A number of factors may influence responses to vaccination, including age, body condition, nutrition, prior immune responses, and genetics
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(Cooper and Herbert 2001, Curtis et al. 2001, Powers et al. 2011). One apparent trend is that animals treated at a younger age, especially before puberty, may have stronger and longer-lasting responses (Brown et al. 1994, Curtis et al. 2001, Stout et al. 2003, Schulman et al. 2013). It is plausible that giving GonaCon-Equine to prepubertal mares will lead to long-lasting infertility, but that has not yet been tested.
To date, short-term evaluation of anti-GnRH vaccines show contraception appears to be temporary and reversible. Killian and others noted long-term effects of GonaCon in some captive mares (2009). However, Baker and others (2017) observed horses treated with GonaCon-B return to fertility after they were treated with a single primer dose; after four years, the fertility rate was indistinguishable between treated and control mares. It appears that a single dose of GonaCon results in reversible infertility but it is unknown if long-term treatment would result in permanent infertility.
Other anti-GnRH vaccines also have had reversible effects in mares. Elhay (2007) noted a return to ovary functioning over the course of 34 weeks for 10 of 16 mares treated with Equity. That study ended at 34 weeks, so it is not clear when the other six mares would have returned to fertility. Donovan and others (2013) found half of mares treated with an anti-GnRH vaccine intended for dogs had returned to fertility after 40 weeks, at which point the study ended. In a study of mares treated with a primer and booster dose of Improvac, 47 of 51 treated mares had returned to ovarian cyclicity within 2 years; younger mares appeared to have longer-lasting effects than older mares (Schulman et al. 2013). In a small study with a non-commercial anti-GnRH vaccine (Stout et al. 2003), three of seven treated mares had returned to cyclicity within 8 weeks after delivery of the primer dose, while four others were still suppressed for 12 or more weeks. In elk, Powers et al. (2011) noted contraception after one dose of GonaCon was reversible. In white-tailed deer, single doses of GonaCon appeared to confer two years of contraception (Miller et al. 2008). Ten of 30 domestic cows treated became pregnant within 30 weeks after the first dose of Bopriva (Balet et al. 2014).
Permanent sterility as a result of single-dose or boostered GonaCon-Equine vaccine or other anti-GnRH vaccines has not been recorded, but that may be because no long-term studies have tested for that effect. It is conceivable some fraction of mares could become sterile after receiving one or more booster doses of GonaCon-Equine, but the rate at which that could be expected to occur is currently unknown. If some fraction of jennies treated with GonaCon-Equine were to become sterile, though, that result would not be contrary to the Wild Free-Roaming Horses and Burros Act of 1971, as amended.
In summary, based on the above results related to fertility effects of GonaCon and other anti-GnRH vaccines, application of a single dose of GonaCon-Equine to gathered wild burros could be expected to prevent pregnancy in perhaps 30 percent to 60 percent of jennies for one year. Some smaller number of jennies should be expected to have persistent contraception for a second year, and less still for a third year. Applying one booster dose of GonaCon to previously-treated jennies should lead to two or more years with relatively high rates (80 percent or more) of additional infertility expected, with the potential that some as-yet-unknown fraction of boostered jennies may be infertile for several to many years. There is no data to support speculation regarding efficacy of multiple boosters of GonaCon-Equine; however, given it is formulated as a highly immunogenic, long-lasting vaccine, it is reasonable to hypothesize that additional boosters would increase the effectiveness and duration of the vaccine.
GonaCon-Equine only affects the fertility of treated animals; untreated animals will still be expected to give birth. Even under favorable circumstances for population growth suppression, gather efficiency might not exceed 85 percent via helicopter and may be less with bait and water trapping. The uncaptured portion of the female population would still be expected to have normally high fertility rates in any given year, though those rates could go up slightly if contraception in other females increases forage and water availability.
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GnRH Vaccine Effects on Other Organ Systems Jennies receiving any vaccine would experience slightly increased stress levels associated with handling while being vaccinated and freeze-marked and potentially microchipped. Newly captured jennies that do not have markings associated with previous fertility control treatments would be marked with a new freeze-mark for the purpose of identifying that jenny and identifying her vaccine treatment history. This information would also be used to determine the number of jennies captured that were not previously treated and could provide additional insight regarding gather efficiency. Most animals recover from the stress of capture and handling quickly once released, and none are expected to suffer serious long-term effects from the fertility control injections, other than the direct consequence of becoming temporarily infertile.
Injection site reactions associated with immunocontraceptive treatments are possible in treated mares (Roelle and Ransom 2009). Whether injection is by hand or via darting, GonaCon-Equine is associated with some degree of inflammation, swelling, and the potential for abscesses at the injection site (Baker et al. 2013). Swelling or local reactions at the injection site are generally expected to be minor in nature, but some may develop into draining abscesses. When the porcine zona pellucida vaccine was delivered via dart, it led to more severe swelling and injection site reactions (Roelle and Ransom 2009), but that was not observed with dart-delivered GonaCon (McCann et al. 2017). Mares treated with one formulation of GnRH-KHL vaccine developed pyogenic abscesses (Goodloe 1991). Miller and others (2008) noted the water and oil emulsion in GonaCon will often cause cysts, granulomas, or sterile abscesses at injection sites; in some cases, a sterile abscess may develop into a draining abscess. In elk treated with GonaCon, Powers and others (2011) noted up to 35 percent of treated elk had an abscess form, despite the injection sites first being clipped and swabbed with alcohol. Even in studies where swelling and visible abscesses followed GonaCon immunization, the longer-term nodules observed did not appear to change any animal’s range of movement or locomotor patterns (Powers et al. 2013, Baker et al. 2017).
The result that other formulations of anti-GnRH vaccine may be associated with less notable injection site reactions in horses may indicate the adjuvant formulation in GonaCon leads a single dose to cause a stronger immune reaction than the adjuvants used in other anti-GnRH vaccines. Despite that, a booster dose of GonaCon-Equine appears to be more effective than a primer dose alone (Baker et al. 2017). Horses injected in the hip with Improvac showed only transient reactions that disappeared within 6 days in one study (Botha et al. 2008), but stiffness and swelling that lasted 5 days were noted in another study where horses received Improvac in the neck (Imboden et al. 2006). Equity led to transient reactions that resolved within a week in some treated animals (Elhay et al. 2007). Donovan and others noted no reactions to the canine anti-GnRH vaccine (2013). In cows treated with Bopriva, a mildly elevated body temperature and mild swelling at injection sites were noted; the reactions subsided within 2 weeks (Balet et al. 2014).
Several studies have monitored animal health after immunization against GnRH. GonaCon-treated mares did not have any measurable difference in uterine edema (Killian 2006, 2008). Powers and others (2011, 2013) noted no differences in blood chemistry except a mildly elevated fibrinogen level in some GonaCon-treated elk. In that study, one sham-treated elk and one GonaCon-treated elk each developed leukocytosis, suggesting there may have been a causal link between the adjuvant and the effect. Curtis et al. (2008) found persistent granulomas at GonaCon-KHL injection sites three years after injection and reduced ovary weights in treated females. Yoder and Miller (2010) found no difference in blood chemistry between GonaCon-treated and control prairie dogs. One of 15 GonaCon-treated cats died without explanation and with no determination about cause of death possible based on necropsy or histology (Levy et al. 2011). Other anti-GnRH vaccine formulations have led to no detectable adverse effects (in
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elephants; Boedeker et al. 2011), though Imboden and others (2006) speculated young treated animals might conceivably have impaired hypothalamic or pituitary function.
Kirkpatrick and others (2011) raised concerns that anti-GnRH vaccines could lead to adverse effects in other organ systems outside the reproductive system. GnRH receptors have been identified in tissues outside the pituitary system, including in the testes and placenta (Khodr and Siler-Khodr 1980), ovary (Hsueh and Erickson 1979), bladder (Coit et al. 2009), heart (Dong et al. 2011), and central nervous system, so it is plausible reductions in circulating GnRH levels could inhibit physiological processes in those organ systems. Kirkpatrick and others (2011) noted elevated cardiological risks to human patients taking GnRH agonists (such as leuprolide), but the National Research Council (2013) concluded the mechanism and results of GnRH agonists would be expected to be different from that of anti-GnRH antibodies; the former flood GnRH receptors, while the latter deprive receptors of GnRH.
GnRH Vaccine Effects on Fetus and Foal Although fetuses are not explicitly protected under the Wild Free-Roaming Horses and Burros Act of 1971, as amended, it is prudent to analyze the potential effects of GonaCon-Equine or other anti-GnRH vaccines on developing fetuses and foals. GonaCon had no apparent effect on pregnancies in progress, foaling success, or the health of offspring in horses immunized in October (Baker et al. 2013); elk immunized 80 to 100 days into gestation (Powers et al. 2011, 2013); or deer immunized in February (Miller et al. 2008). Kirkpatrick and others (2011) noted anti-GnRH immunization is not expected to cause hormonal changes that would lead to abortion in the horse, but this may not be true for the first 6 weeks of pregnancy (NRC 2013). Curtis and others (2001) noted GonaCon-KHL-treated white-tailed deer had lower twinning rates than controls but speculated the difference could be due to poorer sperm quality late in the breeding season when the treated does did become pregnant. Goodloe (1991) found no difference in foal production between treated and control animals.
Offspring of anti-GnRH-vaccine-treated mothers could exhibit an immune response to GnRH (Khodr and Siler-Khodr 1980), as antibodies from the mother could pass to the offspring through the placenta or colostrum. In the most extensive study of long-term effects of GonaCon immunization on offspring, Powers and others (2012) monitored 15 elk fawns born to GonaCon-treated cows. Of those, 5 had low titers at birth and 10 had high titer levels at birth. All 15 were of normal weight at birth and developed normal endocrine profiles, hypothalamic GnRH content, pituitary gonadotropin content, gonad structure, and gametogenesis. All the females became pregnant in their second reproductive season, as is typical. All males showed normal development of secondary sexual characteristics. Powers and others (2012) concluded that suppressing GnRH in the neonatal period did not alter long-term reproductive function in either male or female offspring. Miller and others (2013) reported elevated anti-GnRH antibody titers in fawns born to treated white-tailed deer, but those dropped to normal levels in 11 of 12 of those fawns which came into breeding condition; the remaining fawn was infertile for three years.
Direct effects on foal survival are equivocal in the literature. Goodloe (1991) reported lower foal survival for a small sample of foals born to anti-GnRH-treated mares, but she did not assess other possible explanatory factors such as mare social status, age, body condition, or habitat in her analysis (National Research Council 2013). Gray and others (2010) found no difference in foal survival in foals born to free- roaming mares treated with GonaCon.
There is little empirical information available to evaluate the effects of GnRH vaccination on foaling phenology. It is possible immunocontracepted mares returning to fertility late in the breeding season could give birth to foals at a time that is out the normal range (Nunez et al. 2010, Ransom et al 2013). Curtis and others (2001) did observe a slightly later fawning date for GonaCon-treated deer in the second year after treatment, when some does regained fertility late in the breeding season. In anti-GnRH vaccine
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trials in free-roaming horses, there were no published differences in mean date of foal production (Goodloe 1991, Gray et al. 2010). Unpublished results from an ongoing study of GonaCon-treated, free- roaming mares indicate some degree of aseasonal foaling is possible (D. Baker, Colorado State University, personal communication to Paul Griffin, Bureau of Land Management wild horse and burro research coordinator). Because of the concern that contraception could lead to shifts in the timing of parturitions for some treated animals, Ransom and others (2013) advised that managers should consider carefully before using porcine zona pellucida immunocontraception in small refugia or rare species. Wild horses and burros in most areas do not generally occur in isolated refugia; they are not a rare species at the regional, national, or international level; and genetically they represent descendants of domestic livestock with most populations containing few, if any, unique alleles (National Research Council 2013). Moreover, in porcine-zona-pellucida-treated horses that did have some degree of parturition date shift, Ransom and others (2013) found no negative impacts on foal survival even with an extended birthing season; however, this may be more related to stochastic, inclement weather events than extended foaling seasons. If there were to be a shift in foaling date for some treated mares, the effect on foal survival may depend on weather severity and local conditions; for example, Ransom and others (2013) did not find consistent effects across study sites.
Indirect Effects of GnRH Vaccination One expected long-term, indirect effect on wild jennies treated with fertility control would be an improvement in their overall health. Many treated jennies would not experience the biological stress of reproduction, foaling, and lactation as frequently as untreated jennies, and their better health is expected to be reflected in higher body condition scores. After a treated jenny returns to fertility, her future foals would be expected to be healthier overall and would benefit from improved nutritional quality in the jenny’s milk. This is particularly to be expected if there is an improvement in rangeland forage quality at the same time, due to reduced wild burro population size. Past application of fertility control has shown that mares’ overall health and body condition can remain improved even after fertility resumes. As noted earlier, anecdotal, subjective observations of mares treated with a different immunocontraceptive, porcine zona pellucida, in past gathers showed many of the treated mares were larger, maintained better body condition, and had larger healthy foals than untreated mares.
Body condition of anti-GnRH-treated females was equal to, or better than, that of control females in published studies. Ransom and others (2014b) observed no difference in mean body condition between GonaCon-B-treated mares and controls. Goodloe (1991) found that GnRH-KHL-treated mares had higher survival rates than untreated controls. In other species, treated cats gained more weight than controls (Levy et al. 2011), as did treated young female pigs (Bohrer et al. 2014).
As with porcine zona pellucida, following resumption of fertility, the proportion of jennies that conceive and foal could be increased due to their increased fitness; this has been called a ‘rebound effect.’ Elevated fertility rates have been observed after horse gathers and removals (Kirkpatrick and Turner 1991). More research is needed to document and quantify these hypothesized effects; however, it is believed that repeated contraceptive treatment may minimize this postulated rebound effect.
Because successful fertility control would reduce foaling rates and population growth rates, another indirect effect would be to reduce the number of wild burros that have to be removed over time to achieve and maintain the established appropriate management level. Contraception would be expected to lead to a relative increase in the fraction of older animals. Reducing the numbers of wild burros that would have to be removed in future gathers could allow removal of younger, more easily adoptable excess wild burros and could eliminate the need to send additional excess burros from this area to off-range holding corrals or pastures for long-term holding or to sale. A high level of physical health and future reproductive
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success of fertile jennies within the herd would be expected, as reduced population sizes should lead to more availability of water and forage resources per capita.
Reduced population growth rates and smaller population sizes could also allow continued and increased environmental improvements to range conditions within the project area, which would have long-term benefits to wild burro habitat quality. As the local burro abundance nears, or is maintained at, the level necessary to achieve a thriving natural ecological balance, vegetation resources would be expected to recover, improving the forage available to wild burros and wildlife throughout the area. With rangeland conditions more closely approaching a thriving natural ecological balance and with a less concentrated distribution of wild burros across the wild burro territory, there should also be less trailing and concentrated use of water sources. Lower population density would be expected to lead to reduced competition among wild burros using the water sources and less fighting among burros accessing water sources. Water quality and quantity would continue to improve to the benefit of all rangeland users including wild burros. Wild burros would also have to travel less distance back and forth between water and desirable foraging areas. Should GonaCon-Equine treatment, including booster doses, continue into the future, with treatments given on a schedule to maintain a lowered level of fertility in the herd, the chronic cycle of overpopulation and large gathers and removals might no longer occur. Instead a consistent abundance of wild burros could be maintained, resulting in continued improvement of overall habitat conditions and animal health. While it is conceivable widespread and continued treatment with GonaCon-Equine could reduce the birth rates of the population to such a point that birth is consistently below mortality, that outcome is not likely unless a very high fraction of the jennies present are all treated with primer and booster doses and perhaps repeated booster doses.
Behavioral Effects of GnRH Vaccination Behavioral differences should be considered as potential consequences of contraception with GonaCon. The National Research Council report (2013) noted all successful fertility suppression has effects on mare behavior, mostly as a result of the lack of pregnancy and foaling, and concluded GonaCon was a good choice for use in the program. The result that GonaCon-treated mares may have suppressed estrous cycles throughout the breeding season can lead treated mares to behave in ways that are functionally similar to pregnant mares.
While successful in mares, GonaCon and other anti-GnRH vaccines are expected to induce fewer estrous cycles when compared to non-pregnant control mares. This has been observed in many studies (Garza et al. 1986, Curtis et al. 2001, Dalin et al. 2002, Killian et al. 2006, Dalmau et al. 2015). In contrast, the porcine zona pellucida vaccine is generally expected to lead mares to have more estrous cycles per breeding season, as they continue to be receptive to mating while not pregnant. Females treated with GonaCon had less estrous cycles than control or porcine-zona-pellucida-treated mares (Killian et al. 2006) or deer (Curtis et al. 2001). Thus, concerns about treated mares receiving more courting and breeding behaviors from stallions (Nunez et al. 2009, Ransom et al. 2010) are not generally expected to be a concern for mares treated with anti-GnRH vaccines (Botha et al. 2008).
Ransom and others (2014) found GonaCon-treated mares had similar rates of reproductive behaviors to those of pregnant mares. Among other potential causes, the reduction in progesterone levels in treated females may lead to a reduction in behaviors associated with reproduction. Despite this, some females treated with GonaCon or other anti-GnRH vaccines did continue to exhibit reproductive behaviors, albeit at irregular intervals and durations (Dalin et al. 2002, Stout et al. 2003, Imboden et al. 2006), which is a result similar to spayed (ovariectomized) mares (Asa et al. 1980). Gray (2009) found no difference in sexual behaviors in mares treated with GonaCon and untreated mares. When progesterone levels are low, small changes in estradiol concentration can foster reproductive estrous behaviors (Imboden et al. 2006).
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Owners of anti-GnRH-vaccine-treated mares reported a reduced number of estrous-related behaviors under saddle (Donovan et al. 2013). Treated mares may refrain from reproductive behavior even after ovaries return to cyclicity (Elhay et al. 2007). Studies in elk found GonaCon-treated cows had equal levels of precopulatory behaviors as controls (Powers et al. 2011), though bull elk paid more attention to treated cows late in the breeding season after control cows were already pregnant (Powers et al. 2011).
Kirkpatrick and others (2010) concluded “the larger question is, even if subtle alterations in behavior may occur, this is still far better than the alternative.”
The 2013 National Research Council report provides a comprehensive review of the literature on the behavioral effects of contraception that puts Dr. Nuñez’s (2009, 2010) research into the broader context of all of the available scientific literature, and cautions, based on its extensive review of the literature that:
“. . . in no case can the committee conclude from the published research that the behavior differences observed are due to a particular compound rather than to the fact that treated animals had no offspring during the study. That must be borne in mind particularly in interpreting long- term impacts of contraception (e.g., repeated years of reproductive “failure” due to contraception).”
Gray (2009) and Ransom and others (2014b) monitored non-reproductive behaviors in GonaCon-treated populations of free-roaming horses. Gray and others (2009) found no difference between treated and untreated mares in terms of activity budget, sexual behavior, proximity of mares to stallions, or aggression. Ransom and others (2014b) found only minimal differences between treated and untreated mare time budgets, but those differences were consistent with differences in the metabolic demands of pregnancy and lactation in untreated mares as opposed to non-pregnant treated mares.
As noted in the Bureau of Land Management wild horse and burro handbook (USDI Bureau of Land Management 2010) and described by others (McDonnell 1998) regarding wild burro herd social structure:
Wild burros do not form breeding bands. There are no strong individual bonds other than jenny-foal relationships. Wild burros present themselves as single animals, all-male groups, all-female groups, jenny-foal groups, or mixed groups. All of the groups are variable, and their composition may change at any time. This loose social structure, where all animals are potential breeding partners, maximizes genetic diversity in small or dispersed burro populations.
Some of the older jacks establish a breeding territory but do not prevent other males from entering this area unless there is an estrous female present. It is common for males to roam freely throughout their habitat and breed upon encountering an estrous female. Large male groups may form in the vicinity of an estrous female, and it is normal for the jenny to have multiple breeding partners. Likewise, a solitary jenny or jennies in small groups may pass through territories held by breeding males. Subordinate nonbreeding males are more or less tolerated by the territorial breeding males as they pass through or reside in their territory. In some populations, subordinate males are allowed to breed some of the jennies within the territory of a dominate jack. Nonbreeding males may form all-male bachelor groups which may have a stable submissive alliance with territorial breeding males (McDonnell 1998).
In dispersed populations in a desert environment, breeding efficiency increases as the population densities increase. As daily temperatures increase and water availability decreases, more and more animals will gather around the remaining available water sources. These areas become important areas for maximizing breeding efficiency. This temporary or seasonal increase in population density increases the chance for males to encounter estrous females. Thus, although breeding occurs year-round, increased breeding and foaling may occur during this period of time (USDI Bureau of Land Management 2010).
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Because wild burros have this loose social structure, it is anticipated the use of GnRH vaccines on individual jennies would not have any observable disruptions in the current herd’s social structure.
Genetic Effects of GnRH Vaccination In areas where large numbers of wild horses have recent, ongoing, or both influx of breeding animals from other areas with wild or feral horses, contraception is not expected to cause an unacceptable loss of genetic diversity or an unacceptable increase in the inbreeding coefficient. In any diploid population, the loss of genetic diversity through inbreeding or drift can be prevented by large effective breeding population sizes (Wright 1931) or by introducing new potential breeding animals (Mills and Allendorf 1996). The 2013 National Research Council report recommended managed herds of wild horses and burros would be better viewed as components of interacting metapopulations, with the potential for interchange of individuals and genes taking place as a result of both natural and human-facilitated movements. In the last 10 years, there has been a high realized growth rate in most wild horse and burro populations, such that most alleles that are present in any given mare are likely to already be well represented in her siblings, cousins, and more distant relatives. With the exception of horses in a small number of well-known herd management areas that contain a relatively high fraction of alleles associated with old Spanish horse breeds (National Research Council 2013), the genetic composition of wild horses and burros in lands administered by the Bureau of Land Management and Forest Service is consistent with admixtures from domestic breeds. As a result, in most areas, applying fertility control to a subset of jennies is not expected to cause irreparable loss of genetic diversity. Improved longevity and an aging population are expected results of contraceptive treatment that can provide for lengthening generation time; this result which would be expected to slow the rate of genetic diversity loss (Hailer et al. 2006). Based on a population model, Gross (2000) found an effective way to retain genetic diversity in a population treated with fertility control is to preferentially treat young animals, such that the older animals (which contain all the existing genetic diversity available) continue to have offspring. Similarly, Gross (2000) found that preferentially treating older animals (preferentially allowing young animals to breed) leads to a more rapid expected loss of genetic diversity over time.
Even if it is the case that booster treatment with GonaCon may lead to prolonged infertility, or even sterility, in some jennies, most herd management areas and territories have only a low risk of loss of genetic diversity if logistically realistic rates of contraception are applied to jennies. Wild horses and burros in most herd management areas and territories are descendants of a diverse range of ancestors coming from many breeds of domestic horses. As such, the existing genetic diversity in the majority of herd management areas does not contain unique or historically unusual genetic markers. Past interchange between herd management areas, either through natural dispersal or through assisted migration (that is, human movement of horses) means many areas are effectively indistinguishable and interchangeable in terms of their genetic composition. Roelle and Oyler-McCance (2015) used the VORTEX population model to simulate how different rates of mare sterility would influence population persistence and genetic diversity, in populations with high or low starting levels of genetic diversity, various starting population sizes, and various annual population growth rates. Their results show the risk of the loss of genetic heterozygosity is extremely low except in case where starting levels of genetic diversity are low, initial population size is 100 or less and the intrinsic population growth rate is low (5 percent per year), and very large fractions of the female population are permanently sterilized.
The Hickison wild burro herd is at risk of having low genetic diversity because of a low starting population and being geographically isolated from other burro herds. The population appeared to be down to as few as 8 animals in 1995. Concerns regarding likely inbreeding depression and low genetic viability of the herd prompted the Forest Service to request that the Bureau of Land Management supplement the herd with up to 12 burros from another herd management area (USDA Forest Service
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1994a). Translocation of 8 animals (5 jennies and 3 jacks) did occur in February 1995 from the Selenite Range Herd Area (NV0212), Winnemucca Bureau of Land Management District. The population has since grown from 16 animals (low appropriate management level) to well over 100 animals. Genetic analysis of the current Hickison herd has not been conducted to date, and further data collection and analysis are needed to evaluate herd genetics. Under the action alternatives, augmentation of the herd would occur if determined necessary based on genetic monitoring.
Many factors influence the strength of a vaccinated individual’s immune response, potentially including genetics, but also nutrition, body condition, and prior immune responses to pathogens or other antigens (Powers et al. 2013). One concern that has been raised with regard to genetic diversity is that treatment with immunocontraceptives could possibly lead to an evolutionary increase in the frequency of individuals whose genetic composition fosters weak immune responses (Cooper and Larson 2006, Ransom et al. 2014a). This premise is based on a hypothesis that lack of response to immunocontraceptives could be a heritable trait and the frequency of that trait will increase over time in a population of treated animals. Cooper and Herbert (2001) reviewed the topic in the context of concerns about the long-term effectiveness of immunocontraceptives as a control agent for exotic species in Australia. They argue that immunocontraception could be a strong selective pressure and selecting for reproduction in individuals with poor immune response could lead to a general decline in immune function in populations where such evolution takes place. Other authors have also speculated that differences in antibody titer responses could be partially due to genetic differences between animals (Curtis et al. 2001, Herbert and Trigg 2005).
The Forest Service is not aware of any studies that have quantified the heritability of a lack of response to immunocontraceptives such as porcine zona pellucida vaccine or GonaCon-Equine in horses. At this point, there are no studies available from which one could make conclusions about the long-term effects of sustained and widespread immunocontraception treatments on population-wide immune function. Although a few, generally isolated, feral horse populations have been treated, with high fractions of mares receiving porcine zona pellucida immunocontraception for long-term population control (for example, Assateague Island and Pryor Mountains), no studies have tested for changes in immune competence in those areas. Relative to the large number of free-roaming feral horses and burros in the western United States, immunocontraception has not been used in the type of widespread or prolonged manner that might be required to cause a detectable evolutionary response at a large scale.
Magiafolou and others (2003) clarify that if the variation in immune response is due to environmental factors (body condition, social rank) and not due to genetic factors, there will be no expected effect of the immune phenotype on future generations. Correlations between immune response and physical factors such as age and body condition have been documented; it remains untested whether those factors play a larger role in determining immune response to immunocontraceptives than heritable traits. Several studies discussed above noted a relationship between the strength of individuals’ immune responses after treatment with GonaCon or other anti-GnRH vaccines and factors related to body condition. For example, age at immunization was a primary factor associated with different measures of immune response, with young animals tending to have stronger and longer-lasting responses (Stout et al. 2003, Schulman et al. 2013). It is also possible that general health, as measured by body condition, can have a causal role in determining immune response, with animals in poor condition demonstrating poor immune reactions (Gray 2009, National Research Council 2013). Miller and others (2013) speculated animals with high parasite loads also may have weaker immune reactions to GonaCon.
Correlations between such physical factors and immune response would not preclude a heritable response to immunocontraception. In studies not directly related to immunocontraception, immune response has
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been shown to be heritable (Kean et al. 1994, Sarker et al. 1999). Unfortunately, predictions about the long-term, population-level evolutionary response to immunocontraceptive treatments would be speculative at this point, with results likely to depend on several factors, including the strength of the genetic predisposition to not respond to GonaCon-Equine; the heritability of that gene or genes; the initial prevalence of that gene or genes; the number of jennies treated with a primer dose of GonaCon-Equine (which generally has a short-acting effect, if any); the number of jennies treated with a booster dose of GonaCon-Equine (which appears to cause a longer-lasting effect); and the actual size of the genetically interacting metapopulation of wild burros in the treatment area.
Adaptive Management Adjustments Based on Monitoring Adjustments Based on Utilization Monitoring The direct and indirect effects of this action would be the same as those described under the proposed action.
Adjustments Based on Changes in Plant Composition The direct and indirect effects of this action would be the same as those described under the proposed action.
Adjustments Based on Genetic Diversity The direct and indirect effects of this action would be the same as those described under the proposed action.
Population Control Adjustments Based on Population Monitoring If after 5 years, implementing contraception treatments as described above proves ineffective in reducing the wild burro population by about 64 percent, additional measures would be taken. Catch-treat-release gathers in and outside the wild burro territory and herd management area complex would be conducted to administer surgical ovariectomies to mature females (6 years old and older), coupled with administered contraceptive vaccines to young jennies (less than 6 years of age). Males would be released back onto the territory without any treatment.
The direct and indirect effects of this action would be the same as those described above.
Territory Management Plan The direct and indirect effects of this action would be the same as those described under the proposed action.
Cumulative Effects Following is an analysis of past, present, and reasonably foreseeable future activities that may contribute to cumulative effects to wild burros. A description of activities considered in this analysis is provided in the section “Activities Considered in the Cumulative Effects Analysis for All Alternatives”.
Wild Burro Management Outside the Hickison Wild Burro Territory
Alternative 1 – No Action Potential effects of the no-action alternative, when added to past, present, and reasonably foreseeable future activities of wild burro management outside the Hickison Wild Burro Territory, could negate the benefits of Bureau of Land Management gathers by providing a refugia and source population of burros on National Forest System lands. This, in turn, could continue or even accelerate deterioration of rangeland conditions within, and adjacent to, the project area due to the escalating population of wild
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burros associated with the wild burro territory. As rangeland conditions deteriorate, the health of the burro herd will deteriorate as quality forage becomes scarcer.
Alternative 2 – Proposed Action and Alternative 3 The combined potential effects of the proposed action or alternative 3, along with the potential effects from the past, present, and reasonably foreseeable future activities inside and outside the Hickison Wild Burro Territory, could assist in maintaining the wild burro populations between the herd management area and wild burro territory at the appropriate management level. Maintaining the proposed appropriate management level for the wild burro population occupying the herd management area and wild burro territory could improve rangeland conditions within and outside the territory. An improvement in rangeland conditions would result in more forage available for the burro herd and healthier burros.
Grazing Allotment Management and Range Developments
Alternative 1 – No Action Livestock grazing within project area has the potential to cause impacts similar to those from wild burro grazing. Therefore, continuing to graze livestock at existing levels, while wild burro populations continue to increase, may accelerate degradation of range conditions. As rangeland conditions deteriorate, the health of the burro herd will deteriorate as quality forage becomes scarcer.
Alternative 2 – Proposed Action and Alternative 3 Permitted livestock grazing is anticipated to remain the same on the grazing allotments in, and adjacent to, the Hickison Wild Burro Territory. Reducing the wild burro population to within the upper and lower appropriate management levels as described in either alternative 2 or alternative 3 would relieve much grazing pressure on the vegetative communities. Those communities could improve from “functioning at risk” to “functioning” condition. In addition, the reduced number of burros would leave more forage, allowing livestock to feed without exceeding utilization standards. An improvement in rangeland conditions would result in more forage available for the burro herd and healthier burros.
Mineral Exploration
Alternative 1 – No Action As described above, impacts from mineral exploration are localized and cannot be meaningfully measured or connected to effects of the no-action alternative. Therefore, no cumulative effects from mineral exploration are anticipated.
Alternative 2 – Proposed Action and Alternative 3 As described above, impacts from mineral exploration are localized and cannot be meaningfully measured or connected to effects of these alternatives. Therefore, no cumulative effects from mineral exploration are anticipated from alternative 2 or 3.
Recreation
Alternative 1 – No Action As described above, impacts from recreation activities are localized and cannot be meaningfully measured or connected to effects of the no-action alternative. Therefore, no cumulative effects from recreation are anticipated.
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Alternative 2—Proposed Action and Alternative 3 As described above, impacts from recreation activities are localized and cannot be meaningfully measured or connected to effects of these alternatives. Therefore, no cumulative effects from recreation are anticipated from alternative 2 or 3.
Summary of Findings and Conclusions Under alternative 1, range conditions in the Hickison Wild Burro Territory would continue to degrade over time. Plant communities would reach a “not functioning” condition, and burro health would deteriorate.
Under alternative 2, the proposed action, the wild burro population would be reduced and maintained at an appropriate management level between 16 and 45 animals. The wild burro herd size would be kept within the appropriate management level range by routinely gathering and removing wild burros whenever the herd population exceeds the upper appropriate management level. The proposed action provides a monitoring system that would allow adjustment of the appropriate management level range in response to utilization monitoring, changes in plant community composition, and genetic diversity. The herd size would be adjusted within the appropriate management level range if monitoring results indicate the herd is impacting ecological conditions in the wild burro territory. This process would ensure disturbance and pressure on desirable plants are managed based on site conditions. Management adjustments would increase the rate of recovery and move resource conditions toward desired conditions, allowing plant communities to recover from a “functioning at risk” state. An improvement in rangeland conditions would result in more forage available for the burro herd and healthier burros.
Under alternative 3, the wild burro population would be reduced and maintained to an appropriate management level between 16 and 45 animals, same as alternative 2. The implementation of alternative 3 would achieve the same direct and indirect effects as alternative 2, but the process would occur on a much larger time scale and positive effects (e.g., improved range conditions) would likely take longer to achieve. A combination of limited adoption and fertility control of gathered burros would, over time, reduce and maintain the population within the appropriate management level range. No long-term holding facilities would be used. Alternative 3 is similar to the proposed action in that it provides a monitoring system that would allow adjustment of the appropriate management level range in response to utilization monitoring, changes in plant community composition, and genetic diversity. Under alternative 3, the herd size would be adjusted within the appropriate management level range if monitoring results indicate the herd is impacting ecological conditions in the wild burro territory. This process would ensure disturbance and pressure on desirable plants are managed based on site conditions. Management adjustments would increase the rate of recovery and move resource conditions toward desired conditions, allowing plant communities to recover from a “functioning at risk” state. An improvement in rangeland conditions would result in more forage available for the burro herd and healthier burros.
Rangeland Resources This section evaluates and discloses the potential effects of each alternative to rangeland resources.
Affected Environment The Hickison Wild Burro Territory is located on the Austin/Tonopah Ranger District approximately 20 miles east of Austin, Nevada. The territory consists of 52,570 acres of National Forest System land adjoining 57,275 acres of Bureau of Land Management land (Hickison Herd Management Area) and is managed as a wild burro territory-herd management area complex, or joint management area. The Forest Service has management responsibility for the wild burro territory; the Bureau of Land Management has
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management responsibility for the herd management area portion of the joint management area. One full (Hot Springs winter) grazing allotment and one partial (Stoneberger) grazing allotment managed by the Austin/Tonopah Ranger District of the Humboldt-Toiyabe National Forest lie within the wild burro territory. The Highway 50 right-of-way fence cuts through the herd management area, preventing access to 17,625 acres of the area and limiting the wild burros to the southern portion of the herd management area (figure 3).
The Hot Springs winter allotment is split into two units: the Toquima unit, on the Toquima Range, is the primary focus of this report. The Toiyabe unit, on the Toiyabe Range, is separated from the Toquima unit by Big Smoky Valley and a fenced right-of-way for Nevada Highway 376. Because the Toiyabe unit is inaccessible to burros, it is not analyzed further. The Toquima unit is approximately 62,000 acres and has been used as cattle winter range since the Toiyabe Forest Reserve was established in 1907. The Hickison Wild Burro Territory encompasses 48,900 acres of the Toquima unit in the Hot Springs winter allotment (figure 3).
Only a small portion of the Stoneberger allotment is within the Hickison Wild Burro Territory (figure 3). This portion of the Stoneberger allotment is difficult for livestock to access from the Stoneberger allotment due to rugged terrain and limited water. As a result of this access problem, the part of the Stoneberger allotment that is within the Hickison Wild Burro Territory receives little-to-no use from the cattle that graze the allotment. Superior vegetation exists in the higher elevations of the allotment outside the wild burro territory, so livestock do not need to seek forage in this part of the wild burro territory.
In 1940, Forest Service personnel worked with the permittees to separate grazing use on the Toquima unit, which had originally included both the east and the west sides of the Toquima Mountain Range. The allotment was thus divided into an east side, now known as the Monitor winter allotment, and a west side, the present-day Toquima unit of the Hot Springs winter allotment. When the Toquima unit was separated, 65 head of cattle were allocated to the Monitor winter allotment. In 1970, an allotment management plan was developed which authorized a total of 268 head of cattle from December 1 through March 31 for the entire Hot Springs winter allotment. The allotment management plan allocated 203 head of cattle on the Toquima unit of the allotment. In conjunction with this increase in cattle numbers from 215 head to 268 head, the 1970 allotment management plan authorized the repair of existing water developments and the construction of new water developments to improve livestock distribution on the allotment.
Trespass from domestic livestock has never been a serious problem due to the lack of water during the spring and summer and the relative isolation of the area. Few water developments existed on the allotment, which had caused livestock to concentrate in a limited area leading to poor distribution throughout the rest of the allotment. Areas with no access to water had received little to no grazing from livestock and areas around the existing water developments had been consistently overgrazed.
Humboldt-Toiyabe National Forest personnel have issued term grazing permits for 713 head months of annual forage consumption by domestic livestock on the Toquima unit of the Hot Springs winter allotment and 834 head months of annual forage consumption by domestic livestock on the Stoneberger allotment (table 10). Total permitted livestock use is 1,547 head months or 1.939 animal unit months. No forage consumption amounts or appropriate management levels have been established for the Hickison wild burro herd.
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Table 10. Current permitted livestock use for allotments within the wild burro territory Number of Permitted Permitted Animal Allotment Livestock Class Season of Use Head Months Unit Months Hot Springs Winter: 65 Cattle December 1–May 391 516 Toquima Unita 31 Hot Springs Winter: 80 Cattle October 1-March 322 322 Toquima Unitb 31 Total – Hot Springs 145 N/A N/A 713 838 Winter – Toquima Unit Stonebergerc 237 Cattle June 1–September 834 1,101 15 a and b The Toquima section of the Hot Springs winter allotment has two separate permittees that are permitted to graze cattle for different lengths of season of use. c This information is for the entire Stoneberger allotment. Only a small portion of the allotment is within the territory, and most of that portion is not utilized by livestock from the allotment.
From 2003 to 2017, 713 head months were permitted on the Toquima unit of Hot Springs winter allotment each year for a 15-year total of 10,695 head months. In that time, 7,041 head months total were authorized for use (table 11). Thirty-three percent of the available head months for the last 15 years have not been utilized by the permittees’ on the Toquima unit. The non-use was solely due to resource concerns, including lack of forage, lack of water, persistent drought conditions, and an abundance of burros.
Table 11. Authorized livestock use for allotments within the Wild Burro Territory, in head months (2003–2017) Allotment 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 Hot Springs 429 684 711 711 693 714 389 0 0 322 322 322 715 709 320 Winter Toquima Unit Stonebergera 478 0 830 0 830 832 151 832 832 832 832 832 832 978 834 Total Authorized 907 684 154 711 152 154 540 832 832 115 115 115 154 168 115 1 3 6 4 4 4 7 7 4 a This information is for the entire Stoneberger allotment. Only a small portion of the allotment is within the territory, and most of that portion is not utilized by livestock from the allotment.
From 2003 to 2017, 834 head months a year, or 12,510 head months, total were permitted on the Stoneberger allotment. In that time, 9,925 head months, were authorized for use. Around 21 percent of the available head months for the last 15 years were not utilized by the permittee, because of resource concerns during a drought period and the rest-rotation schedule on the allotment. Because the portion of the wild burro territory within the Stoneberger allotment receives little-to-no use from livestock, this allotment will receive less attention in this report.
Information on the wild burro herd including its history, population data, and distribution is described in the Wild Burros, Affected Environment section. Figure 4 shows authorized livestock numbers and the burro population from 1998 to 2017.
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Figure 3. Grazing allotments in the project area
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Figure 4. Authorized livestock numbers compared to wild burro population (1998 to 2017)
Existing Conditions Plant Phenology—Monthly plant phenology data were collected on the Hot Springs winter allotment and the Hickison Wild Burro Territory from April 2010 through March 2011. Key forage grasses broke winter dormancy in mid-February; had vegetative growth through May; developed seed heads by the end of May; cast seed by the end of June; and began to desiccate by the end of July. Some regrowth occurred during October. The growing season for 2010 had below-normal temperatures and near-normal precipitation (USDA National Agricultural Statistics Service 2011). Winter 2011 had above-average precipitation and snow cover in February and March (Thompson 2011). Though derived from only 1 year of data, this information reflects the general plant growth and seed development for the area; the timing of growth and development may vary by several weeks, depending on available moisture and daytime temperatures.
Plant Community Composition—In 2008, the forest ecologist and the ranger district rangeland management specialist visited and assessed Hot Springs winter allotment and Hickison Wild Burro Territory (appendix 1 in the range specialist report). Concerns had been raised about possible resource damage due to year-round wild burro grazing combined with permitted winter livestock grazing. In previous years, the livestock permittees had removed their animals from the pastures early, due to lack of feed. The permittees noted that trailing by burros was apparent throughout the area and was most prevalent north of the Pete’s Summit road.
The soil surface throughout most of the Hot Springs winter allotment is covered with desert pavement, consisting primarily of mixed rock outwash, while the soil is primarily limestone. The vegetation is mixed desert shrub, which melds into black sagebrush and then into pinyon-juniper as the elevation increases. The areas of concern are the desert shrub and black sagebrush plant communities. The primary shrub species are spiny hopsage (Grayia spinosa), spiny horsebrush (Tetradymia spinosa), Nevada ephedra (Ephedra nevadensis), yellow rabbitbrush (Chrysothamnus viscidiflorus), rubber rabbitbrush (Ericameria nauseosa), greasewood (Sarcobatus vermiculatus), and winterfat (Krascheninnikovia lanata). The grass species are squirreltail (Elymus elymoides), ricegrass (Achnatherum hymenoides), needle and thread grass (Hesperostipa comata), Sandberg bluegrass (Poa secunda), and cheatgrass (Bromus tectorum). The forb species include rockcress (Boechera spp.), tansy mustard (Descurainia spp.), coyote tobacco (Nicotiana
Humboldt-Toiyabe National Forest 67 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment attenuata), halogeton (Halogeton glomeratus), and Great Basin woollystar (Eriastrum sparsiflorum). A State of Nevada protected cactus, sagebrush cholla (Grusonia pulchella), grows in the black sagebrush desert shrub habitat within the allotment.
Foliar cover transects were completed on the north and south ends of the allotment. (See appendix 1 of the range specialist report for additional information on these transects.) On the south end, the vegetative condition was somewhat better than on the north end. In both areas, burro use was evident on native grasses, winterfat, and spiny horsebrush. The winterfat and spiny horsebrush were both hedged extensively, resulting in few winterfat plants and many dead spiny horsebrush plants. Cover of spiny hopsage was high at both sites; this is a low-value forage species.
The south end of the allotment had 29 percent total foliar cover, including 2 percent native grasses and 1 percent was winterfat. The north end had a total of 33 percent foliar cover, none of which was native grasses or winterfat. The south site had 6 percent spiny hopsage, and the north site had 12 percent spiny hopsage. Halogeton and cheatgrass, both nonnative invasive species, were present on both sites. Green rabbitbrush was also present at 5 percent on the south site and 8 percent on the north site, which is high for a desert shrub plant community.
Overall, vegetative composition at the sample sites appears to have been impacted by drought and heavy grazing from cattle and burros. Winterfat, perennial grasses, and desirable forbs should make up a greater percentage of the foliar cover. Spring grazing by cattle and yearlong grazing by burros are likely causing a shift in the plant composition. Other factors affecting ecological condition on this allotment may include prolonged drought and climate change. The forest ecologist reasoned that if plants green up early and become exposed to grazing pressure for a longer time in the spring, the cumulative effects of a shorter growing season and year-round grazing pressure could further reduce abundance and distribution of key forage grass and shrub plant species. Therefore, due to the existing conditions, the forest ecologist recommended that spring and summer grazing be reduced or eliminated.
Plant Utilization --- Eight potential key areas were created in the Hot Springs winter allotment in summer 2012 and were measured in 2012 and 2013. These key areas have been used to document the presence and utilization of key species on the allotment (figure 5 and table 12).
Table 12. Hot Springs winter allotment utilization monitoring in potential key areas Key Area Key Area Key Area Key Area Key Area Key Area Key Area Key Year 1 2 3 4 5 6 7 Area 8 2012 58.5% 46.3% 3.8% 22.5% 36.9% 22.7% 10.2% 2.5% 2013 46.0% 46.2% 20.1% 38.1% 37.9% 26.7% 23.3% 4.8%
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Figure 5. Key area study plots within and near the Hickison Wild Burro Territory
Past utilization studies and actual use reports for the Hot Springs winter allotment indicate that forage utilization was close to or exceeded Forest Service standards on the northern portion of the allotment
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before livestock were authorized to enter. The north portion of Hot Springs winter allotment was the most heavily utilized, while the southern and eastern parts of the allotment had less utilization, likely due to the limited availability of forage in the southern portion of the allotment. As stated in the ecologist’s report from 2008 (appendix 1 in the range specialist report), only 6 percent of the foliar cover on the southern portion of the allotment was native grasses, and in the northern portion, native grasses were found in such minimal amounts that they made up 0 percent of the foliar cover. The limited amount of key forage species at or near the key areas would make the search for food more difficult for foraging animals. The key areas in pinyon/juniper plant communities were found to have 10 percent or less utilization. These pinyon/juniper communities have few native forage species and are considered incapable for grazing. Field inspections documented numerous instances of wild burros across the wild burro territory as well as heavily used trails from the animals (see appendix 3 in the range specialist report). Utilization standards for livestock use, as stated in the term grazing permits for Hot Springs winter allotment, are listed in table 13.
Table 13. Hot Springs winter allotment utilization standards, maximum percent utilization by key species Grass or Forb Shrubs and Trees Vegetation Type Post-Winter Grazing Season Post-Winter Grazing Season Riparian 55% 25% Upland 45% 30%
Rangeland Condition - Assessment Methods The forest plan provides direction to develop scorecards to rate ecological status. This project uses the Central Nevada Riparian Field Guide (USDA Forest Service 1996) and the “Resource Implementation Protocol for Condition Assessment Matrices” (matrices) (USDA Forest Service 2009). Upland study sites were analyzed using the matrices. Riparian studies were evaluated using the Central Nevada Riparian Field Guide scorecards to determine current condition.
Central Nevada Riparian Scorecards The Central Nevada Riparian ecological scorecards were developed to ascertain riparian ecological type classification across National Forest System lands in Central Nevada (USDA Forest Service 1996). The scorecards were developed using data from sampling that was conducted from 1990 through 1993 by the Forest Ecology Team, within the Shoshone, Toiyabe, Toquima, and Monitor Ranges. Ecological status is determined by comparing collected vegetation data to potential natural community, defined by the appropriate ecological type scorecard. The ecological status results are classified as low, moderate, or high similarity to potential natural community.
Matrices The matrices were developed by Humboldt-Toiyabe National Forest personnel for making community- type assessments (USDA Forest Service 2009). They provide an ecological approach and include measurable parameters for soil, vegetation, hydrology, and disturbance factors that indicate whether a vegetation community, and the habitat it represents, is functioning, functioning-at-risk, or nonfunctioning. The matrices supply quantitative measures for field personnel to use to determine the ecological condition of various community types (for example, mountain big sagebrush, pinyon-juniper, and mountain mahogany). Through the matrices, a community type would be correlated to a plant alliance at the field data collection level. The matrices are based on field research, literature reviews, and Natural Resources Conservation Service (NRCS) ecological site descriptions.
Humboldt-Toiyabe National Forest 70 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
The criteria and process included in the matrices was scientifically peer reviewed. The attributes included in the functioning condition category are the desired conditions for the project area. The matrices also describe categories of specific conditions for these same vegetative types that would be considered to be in a declining state from functioning referred to as “functioning-at-risk” and “nonfunctioning,” or unsatisfactory. Vegetative communities in either of these conditions would be considered less than desired. However, for vegetation communities that are functioning-at-risk or nonfunctioning, it is important to determine if the community condition is improving, stable, or declining. This may also be described as trending upward or downward.
Relationship between Desired Conditions, Scorecards, and Matrices Several different but similar terms (late seral, mid-succession, functioning) are used to describe desired (or satisfactory) range conditions in the management direction discussed above. For this analysis, all of these slightly different terms for the desired condition are interpreted as meaning the area would be in a mid or later ecological status and in a stable or upward trend. The mid to late ecological status indicates a relationship to a potential natural community (that is, a condition that would be achieved if there were no interference by humans) and a resilience to disturbance.
The analysis for this project describes the desired condition in terms of whether the area is functioning. The term “functioning” indicates the same concepts as the desired conditions referenced in the forest plan and Forest Service Handbook 2209.21. “Functioning” means a vegetative community has the most appropriate soil and vegetative characteristics that enable it to efficiently process precipitation, reproduce healthy vegetation, and withstand or be resilient to disturbance. It incorporates how well these individual vegetative groups receive and process precipitation and are able to withstand extreme weather, fire, or human caused events or activities without resulting in degraded states.
The condition terms “late seral with a stable or upward trend,” “mid-succession with a stable or upward trend,” and “functioning” all fit within the meaning of “satisfactory condition” as expressed in the forest plan (USDA Forest Service 1986, IV-26). Rangelands are considered to be in functioning-at-risk condition when short-term objectives are being met but functionality criteria are not yet present (Forest Service Handbook 2209.21). This is the case with rangelands that are in “early seral” ecological status, even when there is an upward trend. Table 14 provides a crosswalk for terms used in this analysis.
Table 14. Crosswalk of terms used in Toiyabe forest plan, the Central Nevada Riparian Field Guide, and matrices Central Nevada Forest Plan Riparian Field Guide Ecological Condition Rangeland Condition1 (Scorecards) Matrices Satisfactory Late seral with stable or High Functioning (F) upward trend Satisfactory Mid-succession with Moderate Functioning (F) stable or upward trend Unsatisfactory Late seral with downward Low Functioning-at-Risk (FR) trend Unsatisfactory Mid-succession with Very Low Non-functioning (NF) downward trend Unsatisfactory Early seral Very Low Non-functioning (NF)
1 Per the forest plan and as defined in the Region 4 Range Analysis Handbook (USDA Forest Service 1981).
Humboldt-Toiyabe National Forest 71 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Rangeland Condition - Functional Rating In 2010, range analysis transects were established on five key use areas, as listed in table 15. Figure 6 displays the location of these study areas. When evaluated using the Humboldt-Toiyabe vegetation group matrices, each of the sites was determined to be functionally at risk. In particular, relative cover was lower than normal for herbaceous species indicative of desired function; relative cover for one or more shrub species, such as yellow rabbitbrush (Chrysothamnus viscidiflorus), indicated management problems. A functional conditions matrix for each of these study plots is provided in the range specialist report. These plot evaluations were consistent with the site visit observations and transect results recorded by the forest ecologist and the district rangeland management specialist in 2008 (appendix 1 in the range specialist report).
Table 15. Condition-trend transects in grazing allotments and Hickison Wild Burro Territory Inside/Outside Methods of Vegetation Study Name Year Allotment Territory Study Type Condition Spencer Hot 2010 Hot Springs Inside Point intercept for Desert Shrub Functioning Springs Quad 1 Winter vegetation and at risk ground cover; line intercept for shrub Spencer Hot 2010 Hot Springs Inside Point intercept for Black Functioning Springs Quad 2 Winter vegetation and Sagebrush at risk ground cover; line intercept for shrub Henry Meyer 2010 Hot Springs Inside Point intercept for Pinyon-Juniper Functioning Canyon Winter vegetation and Woodland at risk ground cover; line intercept for shrub Petes Summit 2010 Stoneberger Outside Point intercept for Pinyon-Juniper Functioning Quad 001 vegetation and Woodland at risk ground cover; line intercept for shrub Petes Spring 2012 Hot Springs Inside Nested frequency Riparian Low similarity Winter plot to potential natural community
Humboldt-Toiyabe National Forest 72 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Figure 6. Trend study plots located within and near the wild burro territory
At each of these study plots, shrubs, grasses, and forbs desired for functioning conditions are lacking, while shrubs, trees, and annual plants that are indicative of management problems are present in increasing amounts. For a site to be considered “functioning,” desired grass and forb species, called
Humboldt-Toiyabe National Forest 73 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Group B in the functional conditions matrices, must comprise a certain percentage of the total plant cover. Annual shrubs, forbs, and grasses—Groups C, D, and E in the matrices—put the study plots into the “functioning at risk” or “not functioning” categories. Table 16 through table 18 show the recommended relative plant cover for each functional conditions matrix used. The recorded amounts from each site are given in table 19 through table 22.
Table 16. Recommended relative plant cover for the Desert Shrub matrix Desert Shrub Group Functioning Functioning at Risk Not Functioning Group B—Grasses and Forb Species 30%–90% 10%–30% <10% Indicative of Desired Function Group C—Nonnative and Native Grass <10% 10%–30% >30% Species Indicative of Management Problems Group D—Annual Species Indicative of <3% 3%–10% >10% Ecological Decline Group E—Shrub and Tree Species <15% 15%–40% >40% Indicative of Management Problems
Table 17. Recommended relative plant cover for the Black Sagebrush matrix Black Sagebrush Group Functioning Functioning at Risk Not Functioning Group B—Grasses and Forb Species 15%–40% <15%–5% <5% Indicative of Desired Function Group C—Nonnative Grass Species <20% 20%–30% >30% Indicative of Management Problems Group D—Annual Species Indicative of <5% 5%–20% >20% Management Problems Group E—Shrub and Tree Species <10% 10%–40% >40% Indicative of Management Problems
Table 18. Recommended relative plant cover for the Pinyon-Juniper Woodland matrix Pinyon-Juniper Woodland Group Functioning Functioning at Risk Not Functioning Group A—Common Tree and Shrub 30%–60% 5%–30% <5% for >10 years Species Found in Pinyon-Juniper Woodlands Group B—Grasses and Forb Species 10%–20% forbs 10%-5% forbs <5% forbs and <10% Indicative of Desired Function 30%–60% grasses 10%–30% grasses grasses Group C—Herbaceous Species ≤5% 5%–20% >20% Indicative of Management Problems Pinyon and/or juniper absolute canopy <15% 15%–45% >45% cover
Humboldt-Toiyabe National Forest 74 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Table 19. Recorded relative plant cover for Desert Shrub Group (Spencer Hot Springs Quad 001), 2010 Group Measurement Functional Rating Group A—Common tree and shrub species — — found in Pinyon-Juniper Woodlands Group B—Grasses and forb species indicative of 1%–2% Not functioning management problems Group C—Herbaceous species indicative of Trace Not functioning management problems Group D—Annual species indicative of Cheatgrass and halogeton Functioning at risk management problems Group E—Shrub and tree species indicative of 5%–8% Functioning management problems Pinyon, juniper, or both absolute canopy cover — —
Table 20. Recorded relative plant cover for Black Sagebrush Group (Spencer Hot Springs Quad 002) Group Measurement Functional Rating Group A—Common tree and shrub species — — found in Pinyon-Juniper Woodlands Group B—Grasses and forb species indicative of 11% Functioning at risk management problems Group C—Herbaceous species indicative of 0% Functioning management problems Group D—Annual species indicative of Trace levels of cheatgrass Functioning management problems Group E—Shrub and tree species indicative of 21% Functioning at risk management problems Pinyon, juniper, or both absolute canopy cover — —
Table 21. Recorded relative plant cover for Pinyon-Juniper Woodland Group (Henry Meyer Canyon Plot) Group Measurement Functional Rating Group A—Common tree and shrub species 80%a Functioning found in Pinyon-Juniper Woodlands 30%b Group B—Grasses and forb species indicative of 7%—forbs Functioning at risk management problems 15%—grass Group C—Herbaceous species indicative of 0% Functioning management problems Group D—Annual species indicative of — — management problems Group E—Shrub and tree species indicative of — — management problems Pinyon, juniper, or both absolute canopy cover 19% Functioning at risk a Including pinyon and juniper (PIMO and JUOS) b Not including pinyon and juniper (PIMO and JUOS)
Humboldt-Toiyabe National Forest 75 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Table 22. Recorded relative plant cover for Pinyon-Juniper Woodland Group (Stoneberger Plot) Group Measurement Functional Rating Group A—Common tree and shrub species 85%a Functioning at risk found in Pinyon-Juniper Woodlands 23%b Group B—Grasses and forb species indicative of 4%—forbs Functioning at risk management problems 22%—grass Group C—Herbaceous species indicative of 1% cheatgrass Functioning management problems Group D—Annual species indicative of — — management problems Group E—Shrub and tree species indicative of — — management problems Pinyon, juniper, or both absolute canopy cover 30% Functioning at risk a Including pinyon and juniper (PIMO and JUOS) b Not including pinyon and juniper (PIMO and JUOS)
The 1966 range resource inventory of the Hot Springs winter allotment reported the acres of various “suitability” (historical suitability equals capability) classifications and apparent condition and trend. Table 23 is a summary of that information, taken from the 1970 Hot Springs winter allotment management plan (USDA Forest Service 1970). In 1970, the majority of the acres in the Hot Springs winter allotment were ranked in the “poor” condition class, with an apparent equilibrium in trend. This classification correlates with the majority of the more recent study data in table 15 that indicate a “functioning at risk” state.
Table 23. Acres of trend and suitability classification in the Hot Springs winter allotment (USDA Forest Service 1970) Condition Apparent Primary Class Trend (acres) Secondary Unsuitable Non Range Totals Fair Down 63 — — — 63 Fair Same 432 — — 432 Poor Same 25,171 589 — — 25,760 Poor Down 7,075 — — — 7,075 Very Poor Down 1,779 — — — 1,779 NA Totals 34,088 1,021 15,841 7,055 58,005
Riparian—Riparian ecological sites are scarce across the Hickison Wild Burro Territory and the Hot Springs winter allotment. The forest ecologist established a nested frequency plot at Pete’s Spring in May 2012. The riparian complex was keyed as 1) warm willow mesic graminoid ecological site having Cryofluvent-gravel bar and 2) Artemisia tridentata tridentata/Leymus cincereus–Cryoboroll-trough drainway. These 2 ecological sites were rated at low similarity to potential natural community. As noted by the observer, the meadow area has been diminished to a very small patch, about 6 square meters, too small to sample. Therefore, this transect was placed in the willow type. Burro and cattle use in May was estimated to be heavy on coyote willow (Salix exigua), basin wildrye (Leymus cinereus), and forbs. Hummocks were present, and soil surface compaction appeared to be limiting plant growth; soil disturbance was estimated at 35 percent. Soils were deep and well developed with evidence of periodic flood events. Vegetation should have been much more productive and diverse than what was present. Whitetop (Cardaria pubescens), a noxious weed, was growing in what should be a meadow area.
Humboldt-Toiyabe National Forest 76 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Alternative 1 - No Action
Direct and Indirect Effects Under the no-action alternative, the wild burro population would remain unmanaged and likely continue to increase over time. Increased burro population would result in more hooves and increased hoof action on soils around unimproved springs and stream banks, resulting in further impacts to riparian and wetland condition and water quality. Heavy utilization of forage and water resources would continue. Left unchecked over time, many of the key forage and browse species would be eliminated from the range. Areas of heavy to excessive utilization would expand as the burro herd population grows, resulting in further damage to the vegetation. Vegetation would continue to degrade until the functioning at-risk plant communities become completely non-functional. This could be a potentially non-repairable problem that would lead to erosion and soil loss as well as making the area more vulnerable to weed infestation. Eventually, long-term rangeland health would be jeopardized. In absence of healthy rangelands, wild burro, wildlife, and livestock health would eventually be impacted. This could lead to either increasing numbers of wild burros in poor body condition and, without human intervention, at risk of starvation or death, or lead to increasing numbers of wild burros leaving the territory in search of forage and water resources. Wild burros venturing outside the territory could lead to a decrease in rangeland health in areas not historically grazed by the animals.
Alternative 2 - Proposed Action
Direct and Indirect Effects Implementing the proposed action would immediately reduce the wild burro population to the appropriate management level: between 16 to 45 animals. The process used to determine the proposed appropriate management levels is described in detail in appendix A of the wild burro specialist report. Reducing the number of burros grazing year-round would prevent over-utilization of key forage species and promote re-growth and natural recovery of vegetation. The gather and removal of excess wild burros would decrease the potential for grazing competition between the burros, wildlife, and livestock and ease grazing pressure on the remaining vegetation within the territory. Less grazing pressure would allow young vegetation to grow and develop root systems that would provide healthy plants with better resilience against future wild burro, wildlife, and livestock grazing.
The direct impacts to vegetation from gather and removal operations could include disturbance of native vegetation immediately in and around the temporary trap sites and holding and processing facilities. Impacts could occur from vehicle traffic and the hoof action of penned wild burros, and these impacts could be severe near the corrals or holding facilities. Generally, these activity sites would be small (less than half an acre). Since most trap sites and holding facilities would be reused during recurring wild burro gather operations, any impacts would remain site-specific and isolated in nature. In addition, most trap sites or holding facilities are selected to enable easy access by transportation vehicles and logistical support equipment and would generally be adjacent to or on roads, pullouts, water haul sites, or other flat spots that were previously disturbed.
Removing excess wild burros would reduce the number of hooves and therefore the hoof action on the soil around unimproved springs and stream banks, which should lead to increased stream bank stability, improved riparian habitat conditions, and improved water quality. Hoof action on upland habitats would also decrease. In addition, competition for available water sources would be reduced. Fewer burros would mean less grazing of new plant growth, which in turn would promote long-term vegetation recovery and improved rangeland conditions.
Humboldt-Toiyabe National Forest 77 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Alternative 3
Direct and Indirect Effects The implementation of alternative 3 would achieve the same direct and indirect effects as alternative 2, but the process would occur on a much larger time scale and positive effects would likely take longer to achieve. Implementing alternative 3 would reduce the wild burro population to 16 to 45 animals, but over a much longer frame of time than alternative 2. Reducing the number of burros grazing year-round would prevent overutilization of key forage species and promote regrowth and natural recovery of vegetation. The gather and removal of excess wild burros would decrease the potential for grazing competition between the burros, wildlife, and livestock and ease grazing pressure on the remaining vegetation within the territory. Less grazing pressure would allow young vegetation to grow and develop root systems that would provide healthy plants with better resilience against future wild burro, wildlife, and livestock grazing.
The direct impacts to vegetation from gather operations could include disturbance of native vegetation immediately in and around the temporary trap sites and holding and processing facilities. Impacts could occur from vehicle traffic and the hoof action of penned wild burros, and these impacts could be severe near the corrals or holding facilities. Generally, these activity sites would be small (less than half an acre). Since most trap sites and holding facilities would be reused during recurring wild burro gather operations, any impacts would remain site-specific and isolated in nature. In addition, most trap sites or holding facilities are selected to enable easy access by transportation vehicles and logistical support equipment and would generally be adjacent to or on roads, pullouts, water haul sites, or other flat spots that were previously disturbed. Alternative 3 would allow the use of fertility control treatments to slow population growth. Slower population growth rates will result in the need for fewer gathers. Fewer gathers would result in reduced impacts from gather operations.
Removing or reducing numbers of excess wild burros over a long term period would reduce the number of hooves and therefore the hoof action on the soil around unimproved springs and stream banks, which should lead to increased stream bank stability, improved riparian habitat conditions, and improved water quality. Hoof action on upland habitats would also decrease. In addition, competition for available water sources would be reduced. Fewer burros would mean less grazing of new plant growth, which in turn would promote long-term vegetation recovery and improved rangeland conditions. The implementation of Alternative 3 would achieve the same direct and indirect effects as Alternative 2, but the process would occur on a much larger time scale.
Cumulative Effects Following is an analysis of past, present, and reasonably foreseeable future activities that may contribute to cumulative effects to rangeland resources. A description of activities considered in this analysis is provided in the section, “Activities Considered in the Cumulative Effects Analysis for All Alternatives”.
Wild Burro Management outside the Hickison Wild Burro Territory
Alternative 1—No Action Potential effects of the no-action alternative when added to past, present, and reasonably foreseeable future activities of wild burro management outside the Hickison Wild Burro Territory could negate the benefits of Bureau of Land Management gathers by providing a refugia and source population of burros on National Forest System lands. This in turn could continue or even accelerate deterioration of rangeland conditions within and adjacent to the project area, due to the escalating population of wild burros associated with the wild burro territory.
Humboldt-Toiyabe National Forest 78 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Alternative 2—Proposed Action and Alternative 3 The combined potential effects of the proposed action or alternative 3 along with the potential effects from the past, present, and reasonably foreseeable future activities of inside and outside the Hickison Wild Burro Territory could assist in maintaining the wild burro population between the herd management area and wild burro territory at the appropriate management level. Maintaining the proposed appropriate management level for the wild burro population occupying the herd management area and wild burro territory could improve rangeland conditions within and outside the wild burro territory.
Grazing Allotment Management and Range Developments
Alternative 1—No Action Livestock grazing within project area has the potential to cause impacts that are similar to those caused by wild burro grazing. Therefore, continuing to graze livestock at existing levels, while the wild burro population continues to increase may accelerate degradation of range conditions.
Alternative 2—Proposed Action and Alternative 3 Permitted livestock grazing is anticipated to remain the same on the grazing allotments in and adjacent to the Hickison Wild Burro Territory. Reducing the wild burro population to within the upper and lower appropriate management levels as described in either alternative 2 or alternative 3 would relieve much grazing pressure on the vegetative communities. Those communities could improve from “functioning at risk” to “functioning” condition.
Mineral Exploration
Alternative 1—No Action Because mining projects are typically proposed by private companies, predicting when future mineral exploration and mining activities may occur within the wild burro territory can be difficult. However, it is anticipated that future mining projects that occur would be required to reclaim their mining sites. Under the no-action alternative future rehabilitation efforts after mineral exploration activities would become less and less effective as the wild burro population continues to grow and range conditions continue to deteriorate. Repeated efforts might then be needed to rehabilitate the exploration areas, and wild burros might have to be excluded from the reclaimed areas.
Alternative 2—Proposed Action and Alternative 3 Under alternative 2 or alternative 3, reclamation efforts on mining sites are likely to be more successful due to a decreased number of burros in the area. Reducing the burro population would relieve grazing pressure in the surrounding area, potentially allowing native plants to vegetate the area naturally.
Recreation
Alternative 1—No Action Impacts from recreation activities are localized and cannot be meaningfully measured or connected to effects of the no-action alternative. Therefore, no cumulative effects from recreation are anticipated from the no-action alternative.
Humboldt-Toiyabe National Forest 79 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Alternative 2—Proposed Action and Alternative 3 Impacts from recreation activities are localized and cannot be meaningfully measured or connected to effects of these alternatives. Therefore, no cumulative effects from recreation are anticipated from alternatives 2 or 3.
Summary of Findings and Conclusions Under alternative 1, the territory’s plant communities would continue to degrade over time. Plant communities would reach a “not functioning” condition, and livestock grazing could be reduced or completely removed from the area over time.
Under alternative 2, the wild burro population would be reduced and maintained to an appropriate management level between 16 and 45 animals. The wild burro herd size would be kept within the appropriate management level range by routinely gathering and removing wild burros whenever the herd population exceeds the upper appropriate management level. The proposed action provides a monitoring system that would allow for adjustment of the herd size within the appropriate management level range in response to utilization monitoring, changes in plant community composition and genetic diversity. Under alternative 2, the herd size would be adjusted within the appropriate management level range if monitoring results indicate the herd is impacting ecological conditions in the wild burro territory. This process would ensure disturbance and pressure on desirable plants are managed based on site conditions. Management adjustments would increase the rate of recovery and move resource conditions toward desired conditions, allowing plant communities to recover from a “functioning at risk” state. An improvement in rangeland conditions would result in more forage available for the burro herd and healthier burros. Managing the burro herd within the established appropriate management level range will result in improved range conditions and will allow the Forest Service personnel to better balance the multiple uses, such as livestock grazing, occurring in the area.
Under alternative 3 the wild burro population would be reduced and maintained to an appropriate management level between 16 and 45 animals, same as alternative 2. The implementation of alternative 3 would achieve the same direct and indirect effects as alternative 2, but the process would occur on a much larger time scale and positive effects would likely take longer to achieve. A combination of limited adoption and fertility control of gathered burros would, over time, reduce and maintain the population within the appropriate management level range. No long-term holding facilities would be used. Alternative 3 is similar to the proposed action in that it provides a monitoring system to allow for adjustment of the appropriate management level range in response to utilization monitoring, changes in plant community composition and genetic diversity. The herd size would be adjusted within the appropriate management level range if monitoring results indicate the herd is impacting ecological conditions in the wild burro territory. This process would ensure disturbance and pressure on desirable plants are managed based on site conditions. Management adjustments would increase the rate of recovery and move resource conditions toward desired conditions, allowing plant communities to recover from a “functioning at risk” state. Managing the burro herd within the established appropriate management level range will result in improved range conditions and will allow the Forest Service personnel to better balance the multiple uses, such as livestock grazing, occurring in the area.
Humboldt-Toiyabe National Forest 80 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Water Quality This section evaluates and discloses the potential effects of each alternative to water quality.
Affected Environment The project area lacks any perennial or intermittent streams and contains few natural springs. Most water features that are usable by wild burros within the wild burro territory are springs developed for livestock. Springs, hot and cold, exist in and around the wild burro territory; however, flows from natural springs are more variable and susceptible to drought, making these water sources less dependable. The known water sources within the wild burro territory are shown in figure 7. Burros have historically used water sources outside the wild burro territory, and they will likely continue to do so. Springs (even when surface water is not present) and overflow from wells provide water for riparian ecosystems that are vital for burros, livestock, and wildlife.
The palatability and proximity to water make riparian areas more heavily impacted by grazing species than other habitats. When riparian areas are too heavily used, negative changes can occur to the vegetation and the system’s ability to function and persist. It is difficult to distinguish between use by livestock, wildlife, and wild burros. The few water sources available within the wild burro territory are frequently used by wildlife, livestock, and wild burros; some water sources outside the wild burro territory are also used, although less frequently. These water sources consist of springs, which have typically been developed in some way, and man-made wells. Some of these water sources have an associated riparian area. Typically, riparian areas within the wild burro territory are heavily impacted by livestock, burros, and other wildlife, while springs outside the wild burro territory are less impacted.
Photographs taken in 2010 (see appendix 1 of the water quality report) indicate riparian vegetation is sparse at Pete’s Well, at Clipper Gap Spring, and to a lesser degree, at Pete’s Spring. More recent visits show that no riparian vegetation exists at Peterson and Hunts Burro wells and these wells have become nonfunctional due to theft of the solar panels that provided electricity for the pumps. Clipper Gap Spring is a highly developed spring, and the 2010 photographs indicate that no riparian vegetation grows at the spring source, although willows and other riparian plants are present down-canyon in an area lacking surface water. Pete’s Spring has little surface water, but willows are abundant in some places; however, this spring has also been developed to provide water to livestock and wild burros.
In 2013, the Henry Meyer Spring was visited and photographed (see appendix 1 of the water quality report). The tank at the water development has a crack in the bottom and is in need of repair. During the late July visit, no water was present in the tank or spring box. The spring box did contain moist soil, and trailing to the site indicated burros were using it as a water source earlier in the year.
Riparian conditions and effects to riparian vegetation from the alternatives are described further in the rangeland resources section.
Humboldt-Toiyabe National Forest 81 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Figure 7. Water sources, grazing allotments, and burro management areas in and around the Hickison Wild Burro Territory
Humboldt-Toiyabe National Forest 82 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Direct and Indirect Effects
Alternative 1—No Action Under the no-action alternative, current management and condition trends would continue. No appropriate management level would be established, and the burro population would continue to grow. Under this alternative, the riparian conditions in and around the wild burro territory would remain the same or would continue to deteriorate. The current burro population is approximately three times the proposed upper appropriate management level limit and is likely to continue growing if no appropriate management level is set and no management activities are authorized. A larger population will exacerbate the current riparian conditions.
Alternative 2—Proposed Action The proposed action would reduce the number of burros watering and foraging within the wild burro territory. Riparian areas would continue to receive livestock and wildlife use similar to current conditions, but the burro population would be reduced to within the appropriate management level. Management of the wild burro population would reduce impacts on all riparian areas used by the Hickison wild burro herd. Management, including setting the appropriate management level and authorizing herd gather actions, would reduce the number of animals using riparian areas, thereby reducing impacts. Managing the wild burro population within an appropriate management level will help areas that are currently deteriorating to recover and would help those that are currently moving toward desired condition to recover more rapidly.
Alternative 3 Effects from alternative 3 would be similar to those described above for alternative 2.
Cumulative Effects Following is an analysis of past, present, and reasonably foreseeable future activities that may contribute to cumulative effects to water quality. A description of activities considered in this analysis is provided in the section, “Activities Considered in the Cumulative Effects Analysis for All Alternatives”. The cumulative effects area for water quality is the combined herd management area and wild burro territory (figure 2), which contain 4 hydrologic unit code-6 watersheds. The analysis area includes the entire Henry Meyer Canyon watershed and portions of 3 other watersheds: Santa Fe Creek–Rock Creek, Rutherford Canyon, and Cape Horn–Spencer Hot Springs. Lack of precipitation and surface water features makes analysis of the entire area of these 3 watersheds unnecessary. Surface water is unlikely to flow off the project area and is therefore unlikely to have any influence outside the project area. Additionally, the project area serves as the headwaters for all included watersheds.
Alternative 1—No Action The cumulative effects of alternative 1 to water resources would remain minor; however, the expanding burro population may begin to be more destructive to water resources as animals compete for more limited water and forage resources.
Alternatives 2 and 3 The cumulative effects of alternative 2 and alternative 3 to water resources are likely to be minor over the scale of the project area. At a more localized scale, riparian areas are likely to improve under this alternative due to fewer wild burros using those areas over time. Some of the cumulative impacts, such as mining and recreation, occur in areas that do not receive concentrated use by burros. Riparian areas,
Humboldt-Toiyabe National Forest 83 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
however, are heavily used by wildlife, livestock, and wild burros and these areas show the greatest impacts.
Impacts from recreation and mineral exploration are generally in areas that do not receive heavy burro use. Recreation and mineral exploration occur most closely with wild burro use in the area of Spencer Hot Springs. These springs are popular recreation sites, so the surrounding area is heavily roaded, without much riparian vegetation. Burros may water at the springs when other water sources are not available because of drought or seasonal variation, but these animals are unlikely to graze the immediate area.
The Linka, Conquest, and Hillside mines are also in the area of Spencer Hot Springs. However, the mines ceased production in the late 1950s, and the locations of these mining projects are far enough away from riparian areas and water sources that they would not contribute to cumulative effects if they were returned to production. The Pete’s Summit Project disturbed approximately 2.3 acres in an area not heavily used by burros.
Soils This section evaluates and discloses the potential effects of each alternative to soil resources.
Affected Environment Soil quality is the capacity of a soil to function within natural or managed ecosystem boundaries, sustain plant and animal productivity, maintain or enhance the quality of water and air, and support human activities. Burros have the potential to degrade soil quality directly by trampling soils and indirectly by consuming or trampling vegetation that would otherwise protect and help form soils. Soil compaction physically restricts root growth, reduces nutrient availability, and may reduce water infiltration and storage. The loss of vegetation results in bare ground, which is more susceptible to water and wind erosion and weed invasion. Bare ground has increased runoff from precipitation and has less organic matter available for nutrient cycling.
Soil surveys and data from 2008 rated all soil parameters in the project area as functioning (see appendix A in the soils specialist report). The ecological scorecards indicate the amount of bare ground in the area is within the functioning range; additionally, the scorecards indicate surface organic matter and biological crust is within the functioning range for 2 of the 3 studies. In the third study, this characteristic was determined to be in the functioning-at-risk range. Similarly, the presence of rills was found to be within the functioning range, and the presence of soil pedestalling was found to be within the functioning range for 2 of the 3 studies and within the functioning-at-risk range for the third.
Soil types found within the project area are highly variable in depth and texture. Deeper and finer soils are typically found in the lower-elevation portions of the project area, while the more shallow and coarse soils are found in the higher elevations (table 24). Soils were analyzed using STASTGO data from the Natural Resources Conservation Service website. These data are interpolated from the soil map surrounding the National Forest System lands.
Humboldt-Toiyabe National Forest 84 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Figure 8. Soil erosion risk within the Hickison Wild Burro Territory
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Table 24. Soils found within the Hickison Wild Burro Territory Soil Name Slope Class Landscape Depth Class Texture Deep torriorthents-haplargids- Steep Dissected fans Deep Variable, dominated calciorthids by loam to fine Deep and shallow Gently sloping Dissected Deep, shallow Variable camborthids-durargids- to steep bajadas and (pan) torriorthents hillslopes Deep argiborolls-calciborolls- Gently sloping Rolling Deep Variable, dominated eutroboralfs to rolling plateaus, by fine-loamy basins Deep and shallow Gently sloping Dissected Deep, shallow Variable camborthids-durargids- to steep bajadas and (pan) torriorthents hillslopes Lithic and deep argiborolls- Rugged Mountain and Shallow and Variable argixerolls-rock outcrop valley slopes deep
Soil erosion depends on a variety of variables, from the weather and soil type to the way the area is used. In this analysis, erosion risk was estimated based on grade and is broken into 4 categories: low, medium, high, and very high. These categories were created by classifying the grade, with low representing 0 percent to 10 percent slope, medium representing 10 percent to 25 percent slope, high representing 25 percent to 40 percent slope, and very high representing slopes of 40 percent or greater. Figure 8 displays the erosion risk within the project area. Within the Hickison Wild Burro Territory, approximately 24 percent of the area falls into the low category, 28 percent into the medium, 29 percent into the high, and 19 percent into the very high.
Direct and Indirect Effects
Alternative 1—No Action The no-action alternative may result in the continued increase in herd numbers and geographic expansion of the wild burro herd, which would increase soil compaction and erosion within the project area. Additionally, the increasing population could drive some of the wild burros in the herd to utilize areas outside the current Hickison Joint Management Area, increasing soil compaction and erosion in those areas.
Alternative 2—Proposed Action The proposed action would reduce the burro population in the Hickison Wild Burro Territory. Regardless of which alternative is selected, soil compaction and erosion are more likely to occur in and around the limited riparian and watering areas where burros, wildlife, and livestock concentrate to forage and drink. However, the proposed action would reduce the amount of soil compaction associated with wild burros in these and other areas since the population would be reduced to the appropriate management level. The proposed action would also reduce vegetation removal and impacts from wild burros, thereby reducing soil erosion within the project area.
Alternative 3 The effects under alternative 3 would be the same as the proposed action.
Cumulative Effects Following is an analysis of past, present, and reasonably foreseeable future activities that may contribute to cumulative effects to soils. A description of activities considered in this analysis is provided in the
Humboldt-Toiyabe National Forest 86 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
section, “Activities Considered in the Cumulative Effects Analysis for All Alternatives”. Because effects to soils are typically site-specific, the cumulative effects area for this analysis is the combined herd management area and wild burro territory.
Alternative 1—No Action The cumulative effects of alternative 1 to soil resources could remain minor; however, the expanding burro population could begin to be more destructive to soil resources as animals compete for more limited water and forage resources.
Alternative 2 –Proposed Action Alternatives 2 and 3 would likely cause minor positive impacts to soil resources within the project area. At a more localized scale, soils located in and around riparian areas or watering locations would likely improve more substantially due to fewer burros using those areas over time. Riparian areas and watering locations receive more use from burros, livestock, and wildlife than the surrounding uplands and would therefore benefit more from alternative 2 or alternative 3 compared to the no-action alternative.
Livestock grazing and wild burro grazing contribute in similar ways to soil compaction and erosion. Both livestock and burros will concentrate their use, and therefore their impacts, in riparian areas with desirable foraging vegetation and watering locations. Current data indicate soil resources are functioning or functioning at risk, and this rating would be unlikely to change with the actions proposed in alternative 2 and alternative 3.
Mineral exploration activities often involve overland travel, constructing roads and drilling pads, and additional truck traffic. These activities increase soil compaction and erosion, but the locations of mineral exploration activities would generally not overlap areas affected by wild burros. Therefore, cumulative effects to soils from mineral exploration activities would be minimal to none.
Recreation within the project area typically does not substantially affect soil resources; however, illegal off-road motorized travel associated with these recreational activities does affect soils. Illegal off-road travel is abundant in the area around Spencer Hot Springs, and occasionally recreationists travel off-road illegally. The area around the springs has been heavily traveled by recreational users, to the point that it has essentially become a road. Burros may use these springs as a watering source if other sources are unavailable. However, burros are unlikely to concentrate in the area around the springs, due to the degraded conditions there, and the animals are very unlikely to use the springs when recreational users are present. Off-road impacts by hunters and other recreationists are generally infrequent and diffuse and do not contribute to cumulative effects.
Wildlife This section evaluates and discloses the potential effects of each alternative to terrestrial and aquatic wildlife species, including those listed as threatened, endangered, or candidate by the U.S. Fish and Wildlife Service; those designated as sensitive by the U.S. Forest Service Region 4 sensitive species list (USDA Forest Service 2016); those identified as Humboldt-Toiyabe National Forest management indicator species (USDA Forest Service 1986); birds recognized as regional Partners in Flight conservation priority species (GBBO 2010); bald eagles (Haliaeetus leucocephalus) and golden eagles (Aquila chrysaetos); and other species of concern brought forward by the Nevada Department of Wildlife or the public during scoping/comment periods. An official list of threatened, endangered, and proposed species to consider during this analysis was obtained from the U.S. Fish and Wildlife Service Information for Planning and Consultation (IPaC) website on November 14, 2017, (USDI Fish and Wildlife Service
Humboldt-Toiyabe National Forest 87 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
2017), Consultation Code 08ENVD00-2018-SLI-0088. For more details, refer to the wildlife specialist report (including biological evaluation and assessment) in the project record.
Affected Environment
Vegetation Communities The Hickison Wild Burro Territory is dominated by Wyoming big sagebrush and pinyon/juniper vegetation communities (table 25). At the broader scale, the wildlife analysis area is also dominated by pinyon/juniper and Wyoming big sage, but unlike the wild burro territory, also contains notable amounts of aspen, mountain mahogany, mountain big sage, and riparian associations. Vegetation communities, conditions, and trends are described further in the rangeland resources section.
Table 25. Dominant vegetation types found in the Hickison wildlife analysis area Vegetation type Acres Percent of Wildlife Analysis Area Aspen 1,097 0.9 Barren 278 0.2 Basin big sage 302 0.2 Curl-leaf mountain mahogany 5,347 4.3 Desert shrub 6,885 5.6 Low Sage 7,007 5.7 Mixed shrub/basin shrub 7,750 6.3 Mountain shrub 1,031 0.8 Mountain big sage 11,749 9.5 Mountain grassland 11 0 Pinyon 871 0.7 Pinyon/juniper 48,899 39.8 Riparian aspen 106 0.1 Riparian grassland 14 0 Riparian shrub 299 0.2 Whitebark/limber pine 234 0.2 Wyoming big sage 31,088 25.3 Totals 122,968 100
Species Considered Twenty-two threatened, endangered, proposed or Region 4 sensitive species were considered for potential effects from the proposed action and alternatives. Table 26 lists the U.S. Fish and Wildlife Service threatened, endangered or proposed species; and table 27 lists the Region 4 sensitive species known to occur or potentially occurring in the analysis area. Of these species, four are known or have the potential to occur in the analysis area including the spotted bat, Townsend’s big-eared bat, greater sage-grouse, and northern goshawk and are therefore analyzed further for potential effects (table 28).
There are no known occurrences, suitable habitats are not present, or both for the other 18 species: southwestern willow flycatcher, yellow-billed cuckoo, Lahontan cutthroat trout, bighorn sheep, pygmy rabbit, Sierra Nevada red fox, bald eagle, peregrine falcon, mountain quail, flammulated owl, white- headed woodpecker, three-toed woodpecker, great gray owl, California spotted owl, Columbia spotted
Humboldt-Toiyabe National Forest 88 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment frog, Spring Mountain checkerspot, dark blue, and Morand’s checkerspot. Therefore, these species are not considered further in the analysis.
Table 26. Federally listed wildlife species considered. Common Name Scientific Name Status Southwestern willow flycatcher Empidonax trallii extimus Endangered Yellow-billed cuckoo Coccyzus americanus Threatened Lahontan cutthroat trout Oncorhynchus clarki henshawi Threatened
Table 27. Region 4 sensitive species of concern considered. Common Name Scientific Name Bighorn sheep Ovis canadensis Pygmy rabbit Brachylagus idahoensis Spotted bat Euderma maculatum Townsend’s big-eared bat Corynorhinus townsendii Sierra Nevada red fox Vulpes vulpes necator Bald eagle Haliaeetus leucocephalus Peregrine falcon Falco peregrines anatum Greater sage-grouse Centrocercus urophasianus Mountain quail Oreotyx pictus Flammulated owl Otus flammeolus Northern goshawk Accipiter gentilis White-headed woodpecker Picoides albolarvatus Three-toed woodpecker Picoides tridactylus Great gray owl Strix nebulosa California spotted owl Strix occidentalis occidentalis Columbia spotted frog Rana luteiventris Spring Mountains checkerspot Chlosyne acastus robusta Dark blue Euphilotes ancilla purpura Morand’s checkerspot Euphydryas anicia morandi
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Table 28. Species carried forward for analysis. Species Habitat Potential to Occur in Analysis Area Spotted bat Roosting habitat consists of steep cliffs, Spotted bat distribution and potential habitat rocky outcrops, and rock crevices occur in the analysis area. (Bradley et al. 2005). Foraging habitat includes open woodlands, riparian areas, agricultural fields, pinyon-juniper, and sagebrush. Townsend’s big- Distribution is strongly correlated with the Townsend’s big-eared bat distribution and eared bat availability of caves and abandoned potential foraging/roosting habitat occur in the mines (Bradley et al. 2005). analysis area. Greater sage- Wide variety of sagebrush mosaic Greater sage-grouse distribution, suitable grouse habitats, meadows, and grasslands habitat, and an active lek occur in the analysis (WAPT 2013) area. Northern goshawk Nesting habitat includes coniferous, Typical northern goshawk nesting habitat of mixed conifer, and deciduous forests with aspen stands along creeks and drainages does high canopy closure. In Nevada, not occur within the wild burro territory but does goshawks typically nest in mature aspen occur within the wildlife analysis area. Foraging stands that grow along creeks and habitat has potential to occur in the wild burro drainages (Younk and Bechard 1994). territory. Foraging habitat includes open sagebrush and forested areas. Although goshawks forage in large areas around the nest stand, mature forests remain important for both foraging and roosting.
In addition to the above special status species, management indicator species known to occur or potentially occurring in the analysis area are mule deer, yellow warbler, and macroinvertebrates. Greater sage-grouse and northern goshawk are classified as both management indicator species and R4 sensitive species and, as noted above, are carried forward for analysis. Another management indicator species that may occur in portions of the analysis area is the hairy woodpecker. The hairy woodpecker is associated with snags in conifer habitats. While the species may occur in portions of the analysis area dominated by pinyon-juniper, no cause and effect has been established in the scientific literature between livestock grazing or wild burro use and life history elements for hairy woodpecker, particularly conifer snag availability. Therefore, the hairy woodpecker is not carried forward for analysis.
Fifteen conservation priority migratory bird species have the potential to occur in the analysis area: ferruginous hawk, common poorwill, gray flycatcher, gray vireo, pinyon jay, Virginia’s warbler, green- tailed towhee, greater sage-grouse, Swainson’s hawk, golden eagle, prairie falcon, burrowing ow, sage thrasher, Brewer’s sparrow, and sage sparrow. Pronghorn is a species of interest known to occur in the analysis area. Therefore, each of these species is carried forward in the effects analysis.
Environmental Consequences Species known to occur or potentially occurring in the analysis area are analyzed in this section. A description of activities considered in the cumulative effects analysis for each species is provided in the section, “Activities Considered in the Cumulative Effects Analysis for All Alternatives”.
Summary of Threatened, Endangered, Proposed, and Sensitive Species Determinations Table 29 provides a summary of effects and impacts determinations for federally listed threatened, endangered and proposed species as well as Forest Service sensitive species. These and other species known to occur or potentially occurring in the analysis area are analyzed in detail in the following sections.
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Table 29. Summary of effects determinations for threatened (T), endangered (E), proposed, and sensitive (SS) wildlife species Species Status Alternative 1 Alternative 2 Alternative 3 Southwestern willow flycatcher, E NE NE NE Empidonax trallii extimus Yellow-billed cuckoo, Coccyzus T NE NE NE americanus Lahontan cutthroat trout, Oncorhynchus T NE NE NE clarki henshawi Bighorn sheep, Ovis canadensis SS NI NI NI Sierra Nevada red fo, Vulpes necator SS NI NI NI Pygmy rabbit, Brachylagus idahoensis SS NI NI NI Spotted bat, Euderma maculatum SS MII MB MB Townsend’s big-eared bat, SS MII MB MB Corynorhinus townsendii Bald eagle, Haliaeetus leucocephalus SS NI NI NI Peregrine falcon, Falco peregrines SS NI NI NI anatum Greater sage-grouse, Centrocercus SS MII MB MB urophasianus Mountain quail, Oreotyx pictus SS NI NI NI Flammulated owl, Otus flammeolus SS NI NI NI Northern goshawk, Accipiter gentilis SS MII MB MB White-headed woodpecker, Picoides SS NI NI NI albolarvatus Three-toed woodpecker, Picoides SS NI NI NI tridactylus Great gray owl, Strix nebulosa SS NI NI NI California spotted owl, Strix occidentalis SS NI NI NI Columbia spotted frog, Rana SS NI NI NI luteiventris Spring Mountain checkerspot, Chlosyne SS NI NI NI acastus robusta Dark blue, Euphilotes ancilla purpura SS NI NI NI Morand’s checkerspot, Euphydryas SS NI NI NI anicia morandi NE= No effect; MII= may impact individuals but is not likely to cause a trend to federal listing or loss of viability; NI= No impact; MB= may benefit
Greater Sage-grouse
Alternative 1—No Action
Direct and Indirect Effects Unmanaged wild burro populations within the Hickison Wild Burro Territory could accelerate adverse range conditions within sage-grouse habitat by eliminating food and cover resources. These effects may be especially pronounced during periods of drought, which are frequent in the Great Basin.
Under the no-action alternative, wild burro populations would continue to increase, which could further reduce frequency, production, and abundance of grasses within the analysis area. This decrease in grasses
Humboldt-Toiyabe National Forest 91 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
could negatively impact sage-grouse by eliminating important screening cover during nesting season. Reduction in cover can result in increased predation on nests and birds (Connelly et al. 1991; Schroeder and Baydack 2001; Beever and Aldridge 2011).
Continuing increases in the Hickison Wild Burro Territory wild burro population would result in increasingly heavy utilization of vegetation resources and degradation of plant communities within the wildlife analysis area, limiting the ability of the rangeland to respond to favorable precipitation years. Downward trends in key perennial species would be expected in conjunction with reductions in ecological conditions. Further, vegetation production levels would decrease, severely limiting forage availability and thermal and screening cover for sage-grouse. Sage-grouse habitat degradation would be likely, and this degradation could be irreversible unless an appropriate management level is established to maintain the wild burro population in a thriving natural ecological balance.
Under the no-action alternative, wild burro populations would likely continue to increase and expand outside the wild burro territory. Encroaching wild burros would cause adverse impacts to important summer and brood-rearing habitat by removing vegetation that is critical for sage-grouse food and cover. These conditions would likely lead to reduced body condition of both young and adult grouse which in turn could reduce winter survivorship, lek attendance, nesting success, chick survivorship, and would ultimately result in an overall net loss of reproductive output and subsequent decline in local population levels.
In addition, alternative 1 is inconsistent with current forest plan direction, specifically standards GRSG- HB-ST-068 and GRSG-HB-ST-069 identified in the greater sage-grouse Nevada plan amendment (USDA Forest Service 2015). Alternative 1 also would not meet the desired conditions identified in the greater sage-grouse Nevada plan amendment (GRSG-GEN_DC-003-Desired Condition, table 1b) due to continued habitat degradation.
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory Potential effects of the no-action alternative when added to past, present, and reasonably foreseeable future activities of wild burro management outside the Hickison Wild Burro Territory could negate the benefits of Bureau of Land Management gathers by providing a refugia or source population of burros on National Forest System lands. This, in turn, could continue or even accelerate habitat loss and fragmentation of sage-grouse habitats within the analysis area, due to the escalating population of wild burros associated with the wild burro territory.
Livestock Grazing and Range Developments Livestock grazing within sage-grouse habitat in the wild burro territory has the potential to cause impacts that are similar to those caused by wild burro grazing. Therefore, continuing to graze livestock at existing levels, while wild burro populations continue to increase may accelerate habitat loss and fragmentation within sage-grouse habitats. However, the greater sage-grouse Nevada plan amendment (USDA Forest Service 2015) contains desired conditions and guidelines that provide vegetation retention levels for grazing in sage-grouse habitats. In concert with direction prescribing managing wild burro populations with appropriate management levels, elements in the sage-grouse plan amendment reduce the potential for negative effects resulting from the overlap of livestock and wild burro grazing. Decisions on livestock grazing would be addressed in future environmental analyses on the grazing allotments. This proposal was pursued first because there is less flexibility in the management of wild burros. After the appropriate management level for the Hickison Wild Burro Territory is determined, it would be timely to consider how to manage livestock in allotments that overlap the territory.
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Mineral Exploration Because mining projects are typically proposed by private companies, predicting when future mineral exploration and mining activities may occur within the analysis area can be difficult. Mining projects occurring during critical time periods such as lekking, early brood rearing, or cold snowy winters can stress bird through noise and other disturbances. This stress is further magnified when grouse are in poor physical condition due to reduced nutritional quality of degraded habitats resulting from excessive number of wild burros. However, new mining projects that occur within sage-grouse habitat are expected to include mitigation measures to protect sage-grouse and habitat.
Recreation No cumulative effects from recreation are anticipated from the no-action alternative.
Determination Alternative 1 may impact individuals but is not likely to cause a trend to Federal listing or loss of viability for greater sage-grouse.
The no-action alternative would be inconsistent with current management direction adopted to maintain and enhance sage-grouse habitats. Encroaching wild burros would cause adverse impacts to important summer and brood-rearing habitat by removing vegetation critical for sage-grouse food and cover. These conditions would likely lead to reduced body condition of both young and adult grouse which, in turn, would reduce winter survivorship, lek attendance, nesting success, chick survivorship, and would ultimately result in a net loss of reproductive output and subsequent decline in local population levels. As a result of expanding burros populations within and outside the Hickison Wild Burro Territory, sage- grouse habitats have declined and are expected to continue to decline within the analysis area.
However, sage-grouse habitats within habitat management areas affected by the no-action alternative represent a small proportion (less than 5 percent) of preliminary habitat management areas and general habitat management areas on lands administered by the Humboldt-Toiyabe National Forest for which management direction under the greater sage-grouse forest plan amendment provides for sage-grouse conservation. Management direction for sage-grouse conservation within these habitat management areas is also provided on Bureau of Land Management lands in Nevada under the “Bureau of Land Management in Nevada Record of Decision and Approved Resource Management Plan Amendments for the Great Basin Region, Including the Greater Sage-Grouse Sub-Regions of Idaho and Southwestern Montana, Nevada and Northeastern California, Oregon, Utah” (USDI Bureau of Land Management 2015b). Sage-grouse habitat management areas within the analysis area represent a minute amount (approximately 0.5 percent) of National Forest System and Bureau of Land Management lands in Nevada where management direction is applied to promote sage-grouse conservation. In addition, management direction for sage-grouse conservation has been incorporated into applicable forest plans and Bureau of Land Management resource management plans throughout the species’ range (California, Oregon, Idaho, Utah, Colorado, Wyoming, Montana, North Dakota and South Dakota; USDI Bureau of Land Management 2015b). In summary, while the no-action alternative is likely to negatively impact sage- grouse and sage-grouse habitats within the analysis area, the resulting impacts to the species are minor at scales identified for the Humboldt-Toiyabe National Forest and the state of Nevada, as well as rangewide.
Alternative 2—Proposed Action
Direct and Indirect Effects High concentrations of grazing animals could degrade sage-grouse habitat, especially during the winter, when wildlife, wild burros, and livestock within the Hickison Wild Burro Territory move to lower elevations to access forage and thermal cover. Since sage-grouse rely almost exclusively on sagebrush
Humboldt-Toiyabe National Forest 93 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment during the winter and wild burros are known to occupy portions of winter range containing sagebrush, competition for food and cover between wild burros and sage-grouse would be expected to decrease when wild burro populations are managed within appropriate management level.
Loss of connectivity in the shrub canopy may increase rates of insolation, evapotranspiration, and soil loss at small spatial scales and may lessen habitat value of a site for sage-grouse, which rely on sagebrush for shade, food, nesting, and escape cover (Connelly et al. 2000; Beever and Aldridge 2011). Managing wild burro grazing through the appropriate management level in sage-grouse winter habitat could improve the sagebrush overstory, important for thermal and screening cover in the winter, and make the sage- grouse less vulnerable to avian predators. Further, sage-grouse hens often nest near leks; these nest sites typically have increased sagebrush canopy and grass cover relative to other available habitats and provide crucial screening cover for the nests (Beck and Mitchell 2000; Holloran et al. 2005). Achieving the appropriate management level could enhance sagebrush canopies and increase residual grass cover, which would increase the quality of nesting habitat within the wild burro territory. Improved nesting habitat would likely increase the following year’s nesting success by decreasing nest and chick detectability to predators such as coyotes, bobcats, and common ravens. Further, the likelihood of flushing breeding birds at leks and trampling nests would decrease as burro populations decreased. Sage-grouse habitat would be expected to trend towards achieving the desirable conditions identified in the forest plan (see the wildlife specialist report for more detail) once burros are managed within the appropriate management level and grazing pressure is alleviated.
Population management actions are expected to be limited in duration and frequency and would cause minimal impacts to sage-grouse. Design features associated with the proposed action would minimize impacts to sage-grouse from population management actions by avoiding localized disturbances associated with the proposed action during the breeding season (February 15 to June 30, based on local knowledge).
Temporary holding corrals placed in healthy continuous sagebrush communities could fragment sage-grouse habitat. Therefore, the proposed action incorporates design features that require temporary holding corrals be located outside of contiguous sagebrush habitat, preferably in areas previously disturbed (for example, roads and gravel pits).
Bait stations (water trapping) would be temporary and would not be used as a permanent water source. These temporary water sources would not increase transmission of West Nile virus, because the virus is considered infrequent throughout central Nevada and few confirmed cases have occurred in the state (Espinosa 2012). Individual sage-grouse that may be present in or near gather corrals, bait and water traps, or holding facilities could be temporarily displaced or might avoid the area. However, once gather operations cease in that area, these sage-grouse would likely return to normal activities.
Helicopters may be used when bait trapping is ineffective, but they would not be the primary gather method. Helicopters have been used in the analysis area for other purposes such as wildlife and wild burro census flights. Their use is expected to be limited in duration and frequency. Some sage-grouse may flush or hide from the noise and visual disturbances but are expected to return to normal activities after the helicopter moves away.
The risk of sage-grouse flushing into fences or electric wires is extremely low due to the low density of fences and electricity poles in the analysis area. The majority of the fences and electric wires occur on relatively flat terrain, further decreasing the likelihood of sage-grouse collisions caused by gather-related activities.
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Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory Maintaining the proposed appropriate management level for the wild burro population occupying the herd management area and wild burro territory could improve sage-grouse habitat by reducing the habitat loss and degradation that would occur from excessive wild burro use.
Livestock Grazing and Range Developments Livestock grazing is expected to impact vegetation in the area similarly to the effects caused by wild burro grazing. Sage-grouse habitat would be affected similarly by either type of grazing as high concentrations of grazing animals could fragment sage-grouse habitat and decrease essential vegetation important for thermal cover in the winter, hiding cover making sage-grouse less vulnerable to avian predators, and lekking habitat. The impact of grazing is especially strong during drought cycles, which are common in central Nevada.
Permitted livestock grazing is anticipated to remain the same on the grazing allotments in, and adjacent to the Hickison Wild Burro Territory. Reducing the wild burro population to within the upper and lower appropriate management levels under alternative 2 would relieve much grazing pressure on the vegetative communities. Those communities could improve from “functioning at risk” to “functioning” condition. In addition, the reduced number of burros would leave more forage, allowing livestock to feed without exceeding utilization standards. The anticipated improvement in rangeland conditions would benefit greater sage-grouse and its habitat.
Mineral Exploration and Recreation No cumulative effects from mineral exploration, mining, or recreation are anticipated from the proposed action.
Determination The proposed action may benefit sage-grouse by improving conditions in sagebrush and other habitats through reduction in the burro population to more sustainable numbers.
The proposed action is consistent with management direction described in the greater sage-grouse Nevada plan amendment (USDA Forest Service 2015, attachment B), and meets the applicable desired conditions, standards, and guidelines identified in the “Management Direction” section of this report. GRSG-GEN- ST-006-Standard and GRSG-GEN-GL-007-Guideline pertain to avoidance of disturbing activities during the sage-grouse breeding and nesting seasons. This project is consistent with that direction by incorporating the following design feature into both the proposed action and alternative 3: Gather activities would be restricted to occur outside primary portions of the breeding seasons for greater sage- grouse, migratory birds, and raptors (February 15 to June 30).
Alternative 3
Direct and Indirect Effects Direct and indirect effects would be the same as those in alternative 2-proposed action except that positive benefits for greater sage-grouse (for example, improved habitat conditions) would likely take longer to achieve. Improvements in sage-grouse habitat would be dependent on the success rate of treating burros with fertility control vaccines. Since the rate of success in applying vaccines is largely unknown, it is difficult to estimate the speed with which sage-grouse habitat would improve due to the subsequent reduction in burro population numbers. In general terms, habitat should improve in proportion to the rate of success in achieving the appropriate management level; that is, the decrease in burro population from current levels. Since it is expected that achieving the appropriate management level via application of
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fertility control vaccines would take longer than gathers proposed in alternative 2 – proposed action, subsequent improvements in habitat would also take longer.
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory The combined potential effects of the proposed action along with the potential effects from the past, present, and reasonably foreseeable future activities inside and outside the Hickison Wild Burro Territory could assist in maintaining the wild burro populations between the herd management area and wild burro territory at the appropriate management level. Maintaining the proposed appropriate management level for the wild burro population occupying the herd management area and wild burro territory could improve sage-grouse habitat by reducing the habitat loss and fragmentation that would occur from excessive wild burro use.
Livestock Grazing and Range Developments Livestock grazing is expected to impact vegetation in the analysis area similarly to the effects caused by wild burro grazing. Sage-grouse habitat would be affected similarly by either type of grazing as high concentrations of grazing animals could fragment sage-grouse habitat and decrease essential vegetation important for thermal cover in the winter, hiding cover making sage-grouse less vulnerable to avian predators, and lekking habitat. The impact of grazing is especially strong during drought cycles, which are common in central Nevada.
Permitted livestock grazing is anticipated to remain the same on the grazing allotments in, and adjacent to the Hickison Wild Burro Territory. Reducing the wild burro population to within the upper and lower appropriate management levels under alternative 3 would relieve much grazing pressure on the vegetative communities. Those communities could improve from “functioning at risk” to “functioning” condition. In addition, the reduced number of burros would leave more forage, allowing livestock to feed without exceeding utilization standards. Similar to alternative 2, the anticipated improvement in rangeland conditions would benefit greater sage-grouse and its habitat, although those benefits would take longer to achieve.
Mineral Exploration and Recreation No cumulative effects from mineral exploration, mining, and recreation are anticipated from alternative 3.
Determination Alternative 3 may benefit sage-grouse by improving conditions in sagebrush and other habitats through reduction in the burro population to more sustainable numbers, although benefits would take longer to achieve compared to alternative 2.
The proposed action is consistent with management direction described in the greater sage-grouse Nevada plan amendment (USDA Forest Service 2015, attachment B), and meets the applicable desired conditions, standards, and guidelines identified in the “Management Direction” section of this report.
GRSG-GEN-ST-006-Standard and GRSG-GEN-GL-007-Guideline pertain to pertain to avoidance of disturbing activities during the sage-grouse breeding and nesting seasons. This project is consistent with that direction by incorporating the following design feature into both the proposed action and alternative 3: Gather activities would be restricted to occur outside primary portions of the breeding seasons for greater sage-grouse, migratory birds, and raptors (February 15 to June 30).
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Spotted Bat
Alternative 1—No Action
Direct and Indirect Effects Under the no-action alternative, wild burro populations within the wild burro territory are expected to increase. Increasing populations of wild burros within the analysis area could negatively impact the vegetative health of the plant communities within the wild burro territory, due to the potential for year- round grazing on grasses, forbs, and shrubs. However, wild burros are not associated with spotted bat roosting habitat (steep cliffs or rock outcrops), so increased grazing within the wild burro territory will have no effect on spotted bat roosting habitat.
Studies assessing foraging opportunities for spotted bat as impacted by grazing are limited, especially in the Great Basin. However, it is well documented that wild horses, burros, and livestock grazing individually or in combination can alter vegetation community types (Beever and Brussard 2000, Beever et al. 2008, Ostermann-Kelm et al. 2009, Bock et al. 1984, and Abella 2008). Additionally, changes in insect species composition have been tied to grazing and the associated changes in vegetation (Debano 2006, Parmenter et al. 1994). While these interactions of grazing, insects, and bat foraging opportunities have not been fully articulated, impacts on insect populations are possible which in turn may affect foraging opportunities by spotted bats. Riparian plant community types are of particular importance for bat foraging (Grindal et al. 1999). It is reasonable to assume that in areas where host plant species have been lost or reduced, the prey base is also reduced for insectivorous species such as spotted bat.
Under the no-action alternative, high concentration of grazing by burros within the vegetative communities may decrease spotted bat prey abundance and diversity within the analysis area by altering the vegetative structure. This loss of prey abundance may reduce physical fitness of individual bats leading to a potential reducing in survivorship, reproductive output, and population levels.
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory Potential effects of the no-action alternative when added to past, present, and reasonably foreseeable future activities of wild burro management outside the Hickison wild burro territory could negate the benefits of Bureau of Land Management gathers by providing a refugia or source population of burros on National Forest System lands that move into unoccupied habitats on Bureau of Land Management lands. This, in turn, could continue or even accelerate loss and fragmentation of vegetation that provide important habitats for spotted bat prey species within the analysis area, due to the escalating population of wild burros associated with the wild burro territory.
Livestock Grazing and Range Developments Continued increases in wild burro populations combined with current levels of livestock grazing will accelerate the degradation of vegetation communities that provide habitat for spotted bat prey species.
Mineral Exploration and Recreation No cumulative effects from mineral exploration, mining, or recreation are anticipated.
Determination The no-action alternative may impact individuals but is not likely to cause a trend to Federal listing or loss of viability for spotted bat.
Humboldt-Toiyabe National Forest 97 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Alternative 2—Proposed Action
Direct and Indirect Effects Under the proposed action, reducing grazing pressure within the wild burro territory would have no effect on spotted bat roosting habitat, because wild burros are not associated with rock crevices or sheer cliff faces, where spotted bats roost.
Improved rangeland conditions achieved through managing wild burros within the appropriate management level would benefit spotted bats by enhancing or stabilizing the vegetative communities that support the insect prey bases of this species (Debano 2006). However, this benefit would be difficult to document, because sampling the population sizes, composition, and seasonal abundance of insects is challenging, and grazing impacts to insect populations are hard to quantify and hard to isolate from other environmental factors.
Population management actions are expected to be limited in duration and frequency. Since spotted bats are nocturnal, daytime gather operations utilizing helicopters and temporary holding corrals would have no impact on the species. If artificial water sources are used as a bait trapping method, those water sources would meet Bat Conservation International’s water development standards (Taylor and Tuttle 2007) to avoid obstructions to water sources and the potential for drowning (see “Design Features and Mitigation Measures”).
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory Potential effects of alternative 2 - proposed action when added to past, present, and reasonably foreseeable future activities of wild burro management outside the Hickison Wild Burro Territory could enhance the benefits of Bureau of Land Management gathers by eliminating any refugia or source population of burros on National Forest System lands. This in turn could continue or even accelerate improvements in vegetation communities that provide important habitats for spotted bat prey species within the analysis area, due to the decreased population of wild burros associated with the wild burro territory.
Livestock Grazing and Range Developments Livestock grazing is expected to impact vegetation in the analysis area similarly to the effects caused by wild burro grazing. Habitats for spotted bat prey species would be affected similarly by either type of grazing as high concentrations of grazing animals could fragment habitat and decrease essential vegetation important for thermal cover for over wintering, hiding cover, and flowers for foraging moths and other insects. Decisions on livestock grazing would be addressed in future environmental analyses on the grazing allotments. This proposal was pursued first because there is less flexibility in the management of wild burros. After the appropriate management level for the Hickison Wild Burro Territory is determined, it would be timely to consider how to manage livestock in allotments that overlap the territory.
Mineral Exploration and Recreation No cumulative effects from mineral exploration, mining, or recreation are anticipated.
Determination The proposed action may benefit spotted bat by improving conditions in sagebrush and other habitats for prey species through reduction in the burro population to more sustainable numbers.
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Alternative 3
Direct and Indirect Effects Direct and indirect effects would be the same as those in alternative 2-proposed action except with regard to improvements to habitats for spotted bat prey species resulting from maintaining burros within the appropriate management level.
Improvements in prey species habitat would be dependent the success rate of treating burros with fertility control vaccines. Since the rate of success in applying vaccines is largely unknown, it is difficult to estimate the speed in which habitat would improve due to the subsequent reduction in burro population numbers. In general terms habitat should improve in proportion to the rate of success in achieving the appropriate management level; that is, a decrease in burro population from current level. Since it is expected that achieving the appropriate management level via application of fertility control vaccines would take longer than gathers proposed in alternative 2 – proposed action, subsequent improvements in habitat would also take longer.
Cumulative Effects In general, the cumulative effects of alternative 3 are the same as alternative 2 – proposed action.
Determination Alternative 3 may benefit spotted bat by improving conditions in sagebrush and other habitats for prey species through reduction in the burro population to more sustainable numbers.
Townsend’s Big-eared Bat
Alternative 1—No Action
Direct and Indirect Effects Under the no-action alternative, wild burro populations within the wild burro territory are expected to increase. Increasing populations of wild burros within the analysis area could negatively impact the vegetative health of the plant communities within the wild burro territory, due to the potential for year- round grazing on grasses, forbs, and shrubs. However, wild burros are not associated with Townsend’s big-eared bat roosting habitat of mines and caves; therefore, increased grazing within the wild burro territory will have no effect on this species’ roosting habitat.
Studies assessing foraging opportunities for Townsend’s big-eared bat as impacted by grazing are limited, especially in the Great Basin. However, it is well documented that wild horses, burros, and livestock grazing either individually or in combination can alter vegetation community types (Beever and Brussard 2000, Beever et al. 2008, Ostermann-Kelm et al. 2009, Bock et al. 1984, and Abella 2008). Additionally, changes in insect species composition have been tied to grazing and the associated changes in vegetation (Parmenter et al. 1994). While these interactions of grazing, insects, and bat foraging opportunities have not been fully articulated, impacts on insect populations are possible which in turn may affect foraging by Townsend’s big-eared bats. Riparian plant community types are of particular importance for bat foraging. For example Noctuid moths are obligate users of various wetland and riparian plant species such as Tyha, Salix, Pontederia, Nuphar, Eichhornia, and Polygonum (Pierson et al. 1999). Logically areas where host plant species have been lost or reduced, that the prey base has also been reduced for C. townsendii.
Under the no-action alternative, high concentration of grazing within the vegetative communities may decrease Townsend’s big-eared bat prey abundance and diversity within the analysis area by altering the vegetative structure, diversity of plants species, and decreasing overall plant vigor.
Humboldt-Toiyabe National Forest 99 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory Potential effects of the no-action alternative when added to past, present, and reasonably foreseeable future activities of wild burro management outside the Hickison Wild Burro Territory could negate the benefits of Bureau of Land Management gathers by providing a refugia or source population of burros on National Forest System lands. This in turn could continue or even accelerate loss and fragmentation of vegetation that provide important habitats for Townsend’s bat prey species within and adjacent to the analysis area, due to the escalating population of wild burros associated with the wild burro territory.
Livestock Grazing and Range Developments Continued increases in wild burro populations combined with current levels of livestock grazing will accelerate the degradation of vegetation communities that provide habitat for Townsend’s bat prey species.
Mineral Exploration and Recreation No cumulative effects from mineral exploration, mining, or recreation are anticipated.
Determination The no-action alternative may impact individuals but is not likely to cause a trend to Federal listing or loss of viability for Townsend’s big-eared bat.
Alternative 2—Proposed Action
Direct and Indirect Effects The proposed action would have no effect on Townsend’s big-eared bat roosting habitat of mines and caves because wild burros are not associated with these habitats. However, Townsend’s big-eared bats most likely forage throughout large portions of the wild burro territory. They have been documented at the Conquest Mine located in the analysis area and at the Linka mine which is 0.4 miles to the southwest and immediately adjacent the analysis area. Improved rangeland conditions achieved through managing wild burros within the appropriate management level would benefit Townsend’s big-eared bats by enhancing or stabilizing the vegetative communities that support the insect prey bases of this species (Debano 2006). However, this benefit would be difficult to document, because sampling the population sizes, composition, and seasonal abundance of insects is challenging, and grazing impacts to insect populations are hard to quantify and hard to isolate from other environmental factors.
Population management actions are expected to be limited in duration and frequency. Since Townsend’s big-eared bats are nocturnal, daytime gather operations utilizing helicopters and temporary holding corrals would have no impact on the species. If artificial water sources are used as a bait trapping method, those water sources would meet Bat Conservation International’s water development standards (Taylor and Tuttle 2007) to avoid obstructions to water sources and the potential for drowning (see Design Features and Mitigation Measures).
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory Potential effects of alternative 2 (proposed action) when added to past, present, and reasonably foreseeable future activities of wild burro management outside the Hickison Wild Burro Territory could enhance the benefits of Bureau of Land Management gathers by eliminating any refugia or source population of burros on National Forest System lands. This in turn could continue or even accelerate improvements in vegetation communities that provide important habitats for Townsend’s big-eared bat
Humboldt-Toiyabe National Forest 100 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
prey species within the analysis area, due to the decreased population of wild burros associated with the wild burro territory.
Livestock Grazing and Range Developments Livestock grazing is expected to impact vegetation in the analysis area similarly to the effects caused by wild burro grazing. Habitats for bat prey species would be affected similarly by either type of grazing as high concentrations of grazing animals could fragment habitat and decrease essential vegetation important for thermal cover for over wintering, hiding cover, and flowers for foraging moths and other insects. The impact of grazing is especially strong during drought cycles, which are common in central Nevada.
Mineral Exploration and Recreation No cumulative effects from mineral exploration, mining, or recreation are anticipated.
Determination The proposed action may benefit Townsend’s big-eared bat by improving conditions in sagebrush and other habitats for prey species through reduction in the burro population to more sustainable numbers.
Alternative 3
Direct and Indirect Effects Direct and indirect effects would be the same as those in alternative 2 – proposed action except with regard to improvements to habitats for spotted bat prey species resulting from maintaining burros within the appropriate management level.
Improvements in prey species habitat would be dependent the success rate of treating burros with fertility control vaccines. Since the rate of success in apply vaccines is largely unknown, it is difficult to estimate the speed in which habitat would improve due to the subsequent reduction in burro population numbers. Habitat should improve in proportion to the rate of success in achieving the appropriate management level; that is, a decrease in burro population from current level. Since it is expected that achieving the appropriate management level via application of fertility control vaccines would take longer than gathers proposed in alternative 2 – proposed action, subsequent improvements in habitat would also take longer.
Cumulative Effects In general, the cumulative effects of alternative 3 are the same as alternative 2 – proposed action.
Determination Alternative 3 may benefit Townsend’s big-eared bat by improving conditions in sagebrush and other habitats for prey species through reduction in the burro population to more sustainable numbers.
Northern Goshawk
Alternative 1—No Action
Direct and Indirect Effects Under the no-action alternative, wild burro populations are expected to continuously increase. Higher population numbers would also increase grazing intensity and frequency within the Hickison Wild Burro Territory. The wild burro’s ability to consume grasses, forbs, and shrubs increases the likelihood of altering the vegetative structure of several plant communities, especially during drought periods, when forage availability would be further decreased (Weaver 1974; Fleishner 1994). The reduction in vegetative structure can reduce habitat availability and suitability for several northern goshawk (goshawk) prey species, eventually reducing their abundance. Limited prey availability could impact goshawks by
Humboldt-Toiyabe National Forest 101 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
increasing their energy expenditure during foraging and increasing the nutritional stress of parents and their nestlings.
Further, wild burros would continue to encroach outside the Hickison Wild Burro Territory, potentially into known goshawk nesting habitat and breeding territories within the analysis area in Stoneberger Basin and elsewhere. Increased concentrations of large grazing ungulates within goshawk nesting habitat could reduce understory vegetation in aspen stands, increase soil compaction, and cause trampling and browsing of aspen saplings. Over time, these effects could negatively impact aspen regeneration within goshawk nesting territories, reducing nesting and foraging habitat availability.
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory Potential effects of the no-action alternative when added to past, present, and reasonably foreseeable future activities of wild burro management outside the Hickison Wild Burro Territory could negate the benefits of Bureau of Land Management gathers by providing a refugia or source population of burros on National Forest System lands. This in turn could continue or even accelerate loss and degradation of vegetation communities that provide important foraging or nesting habitats within the analysis area, due to the escalating populations of wild burros associated with the wild burro territory.
Livestock Grazing and Range Developments Continued increases in wild burro populations combined with current levels of livestock grazing will accelerate the degradation of vegetation communities that could provide foraging and nesting habitats for goshawks.
Mineral Exploration and Recreation No cumulative effects from mineral exploration, mining, or recreation are anticipated.
Determination The no-action alternative may impact individuals but is not likely to cause a trend to Federal listing or loss of viability for northern goshawk.
Alternative 2—Proposed Action
Direct and Indirect Effects Northern goshawk nesting habitats of mature aspen stringers associated with perennial streams do not occur within the wild burro territory. However, these habitats with known occupied nests do occur in the analysis area within Stoneberger Basin where burros are known to have expanded.
Since breeding and nesting habitat is absent and the closest documented nest is at least 6 miles outside the wild burro territory, goshawks are unlikely to frequent the wild burro territory during the breeding season. However, dispersed juveniles or wintering goshawks may forage on small mammals and avian species within the sagebrush and pinyon-juniper communities in the wild burro territory. Goshawks have a broad prey base, so the impacts of grazing on foraging goshawks have not been well documented, especially in Nevada. The proposed action would enhance sagebrush canopies and seed production and increase residual grass cover by maintaining proper utilization levels, ultimately improving habitat quality for goshawk prey species. Further, managing burros within the upper and lower appropriate management level could increase seed, fruit, and nut production within the plant communities (that is, goshawk prey habitat), enriching the diversity and availability of prey for foraging goshawks. In addition, the proposed action would decrease the potential for burros to encroach into known goshawk nesting habitat and
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breeding territories within the analysis area in Stoneberger Basin and elsewhere. The result would be a decrease in potential impacts to understory vegetation that support some goshawk prey species.
Foraging goshawks are likely to avoid bait stations, corrals, and holding facilities during gather operations. However, once operations cease, individual goshawks would be expected to resume normal activities. Even though goshawks are likely to avoid structures associated with gather operations, artificial water sources used to bait trap wild burros could attract goshawks, especially if no wild burros are occupying the trap. Therefore, artificial water sources at bait trapping locations would be designed to allow access and escape for raptors consuming water at these sites. For example, the artificial water source would have a lip wide enough for raptors to perch, a water level high enough for raptors to access the water, and escape ramps.
Helicopters may be used when bait trapping is ineffective, but they would not be the primary gather method. Helicopters have been used in the analysis area for other purposes, such as wildlife and wild burro census flights. Their use is expected to be limited in duration and frequency. Some goshawks may flush from the noise and visual disturbance associated with the moving helicopter but are expected to return to normal activities after the helicopter moves away. Since goshawk nesting habitat does not occur in the wild burro territory, helicopter activity would have no effect on nesting goshawks within that portion of the analysis area. If gather operations target wild burro populations outside the Hickison Wild Burro Territory (for example, Stoneberger Basin), active goshawk nests would be largely protected from helicopter disturbance from February 15 to June 30 during the incubation portion of the breeding period when goshawks are most sensitive to disturbance (Roberson et al. 2005). For gather operations utilizing helicopters during the later portion of the breeding season (July 1 to August 15) known goshawk nests would be protected from helicopter disturbance and the district biologist would be contacted for an appropriate nest buffer (“Design Features and Mitigation Measures” section).
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory Potential effects of alternative 2 - proposed action when added to past, present, and reasonably foreseeable future activities of wild burro management outside the Hickison Wild Burro Territory could enhance the benefits of Bureau of Land Management gathers by eliminating any refugia or source population of burros on National Forest System lands. This in turn could continue or even accelerate improvements in vegetation communities that provide important habitats for foraging and potentially nesting by goshawks within the analysis area, due to the decreased population of wild burros associated with the wild burro territory.
Livestock Grazing and Range Developments Livestock grazing is expected to impact vegetation in the analysis area similarly to the effects caused by wild burro grazing. Habitats for goshawk prey species would be affected similarly by either type of grazing as high concentrations of grazing animals could negatively impact habitat for various prey species.
The greater sage-grouse Nevada plan amendment (USDA Forest Service 2015, attachment B) contains desired conditions and guidelines that provide vegetation retention levels for grazing in sagebrush- dominated areas, some of which abut pinyon-juniper habitats that may be occupied by goshawks during winter. In concert with direction to manage wild burro populations with the appropriate management level, elements in the sage-grouse plan amendment reduce the potential for negative effects resulting from the overlap of livestock and wild burro grazing in areas where northern goshawk foraging potentially overlap with mapped sage-grouse habitats.
Humboldt-Toiyabe National Forest 103 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Mineral Exploration and Recreation No cumulative effects from mineral exploration, mining, or recreation are anticipated.
Determination The proposed action may benefit northern goshawk.
Alternative 3
Direct and Indirect Effects Direct and indirect effects would be the same as those in alternative 2 – proposed action except with regard to improvements to habitats for goshawk prey species resulting from maintaining burros within the appropriate management level.
Improvements in prey species habitat will be dependent the success rate of treating burros with fertility control vaccines. Since the rate of success in apply vaccines is largely unknown, it is difficult to estimate the speed in which habitat would improve due to the subsequent reduction in burro population numbers. Habitat should improve in proportion to the rate of success in achieving the appropriate management level; that is, a decrease in burro population from current level. Since it is expected that achieving the appropriate management level via application of fertility control vaccines would take longer than gathers proposed in alternative 2 – proposed action, subsequent improvements in habitat would also take longer.
Cumulative Effects In general, the cumulative effects of alternative 3 are the same as alternative 2 – proposed action.
Determination Alternative 3 may benefit northern goshawk.
Mule Deer
Alternative 1—No Action
Direct and Indirect Effects Under the no-action alternative, wild burro populations are expected to continuously increase. The wild burro’s ability to consume grasses, forbs, and shrubs increases the likelihood of altering the vegetative structure and composition of plant communities, especially during drought periods, when forage availability will be further decreased.
Wild burros prefer grasses and forbs but opportunistically switch to shrubs when necessary. Mule deer depend on high-quality browse and forbs to meet their nutritional requirements; they cannot switch their diet composition and subsist on low-quality forage the way wild burros can (Marshal et al. 2012). When their preferred forage becomes limited, wild burros can subsist on species unsuitable to mule deer. Mule deer may become nutritionally stressed if they cannot find enough of the high-quality forage they require. Therefore, wild burros may have a competitive advantage in highly variable, arid environments. This advantage is likely at work within the Hickison Wild Burro Territory. Grasses are already infrequent and limited, so wild burros may be relying more heavily on browse species in this area.
Since wild burros have higher forage consumption rates than mule deer, excess wild burros in mule deer habitat can negatively affect forage and cover availability for mule deer. Desirable shrubs, such as ephedra, Wyoming big sagebrush, low sagebrush, shadscale, and saltbush, are most likely to be utilized by mule deer and wild burros for food and cover during winter. Excess herbivory within these shrub
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communities may delay or prevent seed production and decrease plant vigor (Wambolt and Hoffman 2004).
Further, wild burros would continue to encroach outside the Hickison Wild Burro Territory, potentially into mule deer summer habitat (for example, Stoneberger Basin). Increased concentrations of large grazing ungulates within mule deer summer habitat could reduce understory vegetation, critical for fawning cover. Encroaching wild burros would also consume forbs, which mule deer depend on during the spring and summer. In addition, encroaching wild burros adversely impact important water sources by removing or trampling vegetation and causing increased soil compaction (Beever and Herrick 2006).
Under the no-action alternative, wild burro populations are expected to continuously increase. The growing population of wild burros would increase grazing intensity and frequency within the Hickison Wild Burro Territory. The wild burro’s ability to consume grasses, forbs, and shrubs increases the likelihood of altering the vegetative structure of several plant communities, especially during drought periods, when forage availability would be further decreased. The existing overpopulation of wild burros would decrease forage and cover availability and increase competition between mule deer and wild burros for forage, limited water resources, and cover.
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory Potential effects of the no-action alternative when added to past, present, and reasonably foreseeable future activities of wild burro management outside the Hickison Wild Burro Territory could accelerate habitat loss and fragmentation of mule deer habitat within the analysis area, due to the escalating population of wild burros associated with the wild burro territory.
Livestock Grazing and Range Developments Livestock grazing within mule deer habitat in the analysis area is expected to cause impacts that are similar to those caused by wild burro grazing. Therefore, continuing to graze livestock at the same intensity as occurred historically, while wild burro populations continue to increase may accelerate habitat loss and fragmentation within mule deer habitat.
Mineral Exploration Mineral exploration projects are typically limited to a small area and with a short, typically 1-year, implementation window. Requirements for reclaiming and revegetating disturbed areas are normally required. Impacts are limited to a temporary displacement of mule deer into other adjacent habitats. Due to the limited short-term nature of mineral exploration projects, they are not considered cumulative with the increasing burro population resulting from alternative 1.
Development of permanent or long-term mines has the potential to displace mule deer from suitable habitats on a permanent or extended basis. This displacement in turn has the potential to further concentrate mule deer and burros in the same areas. Since burros have a competitive advantage over mule deer in foraging, deer would likely suffer from reduced foraging opportunities and subsequently reduced physical fitness and reduced survivability. As burro numbers increase under the no-action alternative and habitats continue to decline, the cumulative impact from other activities that impact foraging habitats would become more intense.
Recreation No cumulative effects from recreation are anticipated from the no-action alternative.
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Determination The 122,342 acres of mule deer habitats within the analysis area represent approximately 3.4 percent of habitat on the Humboldt-Toiyabe National Forest as a whole. Although the no-action alternative is likely to negatively impact habitats within the analysis area, the change in habitat quality within the analysis area will not alter the existing trend in the habitat, nor will it lead to a change in the distribution of mule deer, across the entire Humboldt-Toiyabe National Forest.
Alternative 2—Proposed Action
Direct and Indirect Effects Under the proposed action, managing wild burro populations at levels compatible with the resource capabilities would likely improve mule deer habitat. Habitat overlap between wild burros and mule deer is most likely to occur on winter ranges within the wild burro territory, and to a lesser extent at higher elevations in other portions of the analysis area. Managing wild burro populations within the upper and lower appropriate management level could increase residual forage and cover for mule deer, stimulate leader growth on browse species, increase seed production, decrease hedging, and increase vigor of the sagebrush and salt desert scrub communities. Over time, grasses would be expected to increase production and frequency, which could reduce competition for browse species between wild burros and mule deer.
Temporary gather corrals and bait stations could impact some vegetation by concentrating wild burros in a small area. However, the disturbed vegetation would likely recover, and the effects to mule deer habitat would be negligible.
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory The combined potential effects of the proposed action along with the potential effects from the past, present, and reasonably foreseeable future activities of inside and outside the Hickison Wild Burro Territory could assist in maintaining the wild burro populations between the herd management area and wild burro territory at the appropriate management level. Maintaining the proposed appropriate management level for the wild burro population in an ecological balance with the rangeland could improve mule deer habitat by increasing available forage, screening cover, and thermal cover during winter.
Livestock Grazing and Range Developments Livestock grazing is expected to impact vegetation similarly to the effects caused by wild burro grazing. Decisions on livestock grazing would be addressed in future environmental analyses on the grazing allotments. This proposal was pursued first because there is less flexibility in the management of wild burros. After the appropriate management level for the Hickison Wild Burro Territory is determined, it would be timely to consider how to manage livestock in allotments that overlap the territory.
Mineral Exploration Both minerals exploration and actual mine implementation have potential to impact mule deer and their habitats. While the reduction of burro numbers through alternative 2 – proposed action would benefit mule deer, it is unlikely to interact cumulatively with mining activities to impact mule deer in either a positive or negative manner.
Recreation No cumulative effects from recreation are anticipated from the proposed action.
Humboldt-Toiyabe National Forest 106 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Determination The 122,342 acres of mule deer habitats within the analysis area represent approximately 3.4 percent of habitat on the Humboldt-Toiyabe National Forest as a whole. Although the proposed action is expected to benefit mule deer habitats within the analysis area, the change in habitat quality on 52,242 acres in the Hickison Wild Burro Territory project will not alter the existing trend in the habitat, nor will it lead to a change in the distribution of mule deer, across the entire Humboldt-Toiyabe National Forest.
Alternative 3
Direct and Indirect Effects Direct and indirect effects would be the same as those in alternative 2 – proposed action except with regard to improvements to habitats resulting from maintaining burros within the appropriate management level.
Improvements in habitat will be dependent on the success rate of treating burros with fertility control vaccines. Since the rate of success in applying vaccines is largely unknown, it is difficult to estimate the speed in which habitat would improve due to the subsequent reduction in burro population numbers. Habitat should improve in proportion to the rate of success in achieving the appropriate management level; that is, a decrease in burro population from current levels. Since it is expected that achieving the appropriate management level via application of fertility control vaccines would take longer than gathers proposed in alternative 2 – proposed action, subsequent improvements in habitat would also take longer.
Cumulative Effects In general, the cumulative effects of alternative 3 are the same as alternative 2 – proposed action.
Determination Although alternative 3 is expected to benefit mule deer habitats within the analysis area, the change in habitat quality within the analysis area will not alter the existing trend in the habitat, nor will it lead to a change in the distribution of mule deer, across the entire Humboldt-Toiyabe National Forest.
Yellow Warbler
Alternative 1—No Action
Direct and Indirect Effects Under the no-action alternative, wild burro populations are expected to continuously increase and encroach outside the Hickison Wild Burro Territory. Increased concentrations and expansion of wild burros within yellow warbler habitat could remove vegetative and nesting cover, increase soil compaction, reduce foraging habitat, and cause trampling of seedlings. Over time, these effects could negatively impact willow stands, reducing habitat suitability for yellow warblers.
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory Potential effects of the no-action alternative, when added to past, present, and reasonably foreseeable future activities of wild burro management outside the Hickison Wild Burro Territory, could accelerate habitat loss and fragmentation of yellow warbler habitat within the willows stands in the analysis area.
Livestock Grazing and Range Developments Impacts from livestock grazing within willow stands are expected be similar to impacts from wild burro grazing within willow stands. Therefore, continuing to graze livestock at the same intensity as occurred
Humboldt-Toiyabe National Forest 107 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
historically, while wild burro populations continue to increase, may accelerate habitat loss and fragmentation within yellow warbler habitats.
Mineral Exploration Future mineral exploration and mining activities that occur within willow stands are likely to cause yellow warbler habitat loss and fragmentation.
Recreation No cumulative effects from recreation are anticipated from the no-action alternative.
Determination An estimated 421 acres of potential yellow warbler habitat exists within the analysis area, which represents approximately 1.5 percent of habitat on the Austin/Tonopah Ranger District. Although the no- action alternative may continue to negatively impact willow habitats within the analysis area, this alternative will not alter the existing trend in the habitat, nor will it lead to a change in the distribution of yellow warbler, across the entire Humboldt-Toiyabe National Forest.
Alternative 2—Proposed Action
Direct and Indirect Effects Wild burros travel along drainages and washes where willows may occur, and they utilize willow stands while seeking shade, forage, or water. Their concentrated use of willow stands could eventually lead to trampling, soil compaction, and overutilization of the willow stands, and these effects could degrade yellow warbler habitat. By alleviating grazing pressure and managing wild burros in a thriving natural ecological balance, the proposed action is expected to decrease concentrated use within willow stands and improve habitat for the yellow warbler.
Gather operations associated with the proposed action would not occur within potential yellow warbler habitat (see “Design Features and Mitigation Measures” section) and, therefore, would not affect yellow warbler nesting habitat. Under the proposed action, screening cover and foraging habitat for migrating yellow warblers is likely to improve, reducing predation risk for yellow warblers within the analysis area.
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory The combined potential effects of the proposed action along with the potential effects from the past, present, and reasonably foreseeable future activities of inside and outside the Hickison wild burro territory could assist in maintaining the wild burro populations between the herd management area and wild burro territory at the appropriate management level. Maintaining the proposed appropriate management level for wild burros within the appropriate management level could reduce yellow warbler habitat loss and fragmentation within willow stands.
Livestock Grazing and Range Developments Livestock grazing is expected to cause impacts to vegetation that are similar to the effects caused by wild burro grazing. These impacts to vegetation would likely affect yellow warbler habitat. High concentrations of grazing animals could fragment yellow warbler habitat, especially during drought cycles, which are common in central Nevada. Decisions on livestock grazing would be addressed in future environmental analyses on the grazing allotments. This proposal was pursued first because there is less flexibility in the management of wild burros. After the appropriate management level for the Hickison Wild Burro Territory is determined, it would be timely to consider how to manage livestock in allotments that overlap the territory.
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Mineral Exploration and Recreation No cumulative effects from mineral exploration, mining, and recreation are anticipated from the proposed action.
Determination It is estimated that approximately 421 acres of potential yellow warbler habitat exists within the analysis area, which represents approximately 1.5 percent of habitat on the Austin/Tonopah Ranger District. Although the proposed action may benefit willow habitats within the analysis area, this alternative will not alter the existing trend in the habitat, nor will it lead to a change in the distribution of yellow warbler, across the entire Humboldt-Toiyabe National Forest.
Alternative 3
Direct and Indirect Effects Direct and indirect effects of alternative 3 would be the same as those in alternative 2 – proposed action except with regard to improvements to habitats resulting from maintaining burros within the appropriate management level.
Improvements in habitat would depend on the success rate of treating burros with fertility control vaccines. Since the rate of success in applying vaccines is largely unknown, it is difficult to estimate the speed in which habitat would improve due to the subsequent reduction in burro population numbers. Habitat should improve in proportion to the rate of success in achieving the appropriate management level; that is, a decrease in burro population from current levels. Since it is expected that achieving the appropriate management level via application of fertility control vaccines would take longer than gathers proposed in alternative 2 – proposed action, subsequent improvements in habitat would also take longer.
Cumulative Effects In general, the cumulative effects of alternative 3 are the same as alternative 2 – proposed action.
Determination Although alternative 3 may benefit willow habitats within the analysis area, this alternative will not alter the existing trend in the habitat, nor will it lead to a change in the distribution of yellow warbler, across the entire Humboldt-Toiyabe National Forest.
Macroinvertebrates
Alternative 1—No Action
Direct and Indirect Effects Under this alternative, the riparian conditions in and around the wild burro territory would remain the same or would continue to deteriorate. The current burro population is likely to continue increasing if no appropriate management level is set and no management activities are authorized. A larger population will exacerbate the current riparian conditions.
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory No additional and overlapping effects would be expected from wild burro management outside the Hickison Wild Burro Territory.
Humboldt-Toiyabe National Forest 109 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Livestock Grazing and Range Developments Impacts from livestock use of unprotected springs would be similar to impacts from wild burro grazing. Therefore, continuing to graze livestock at existing rates, while wild burro populations continue to increase, could accelerate spring deterioration.
Mineral Exploration and Recreation No additional and overlapping effects are expected to result from mineral exploration and recreation.
Determination The wild burro territory supports only several springs, most of which are developed for livestock use. These represent a minute fraction of the approximately 1,390 springs that are mapped within the Austin/Tonopah Ranger District. Although the no-action alternative could continue to negatively impact spring habitats within the wild burro territory as well as springs and riparian habitats within the remainder of the analysis area, this alternative would not alter the existing trend in habitat, nor would it lead to a change in the distribution of macroinvertebrates, across the entire Humboldt-Toiyabe National Forest.
Alternative 2—Proposed Action
Direct and Indirect Effects The proposed action would reduce the number of burros watering and foraging within the wild burro territory. Spring sites would continue to receive livestock and wildlife use similar to current conditions, but the burro population would be reduced to at least half of the current population. Management of the burro population would reduce impacts on all riparian areas used by the Hickison wild burro herd. Management, including setting the appropriate management level and authorizing herd gather actions, would reduce the number of animals using springs, thereby reducing impacts.
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory No cumulative effects from wild burro management outside the Hickison Wild Burro Territory are anticipated from the proposed action.
Livestock Grazing and Range Developments Livestock grazing would be expected to cause impacts to spring habitats that are similar to the effects caused by wild burro grazing. Decisions on livestock grazing would be addressed in future environmental analyses on the grazing allotments. This proposal was pursued first because there is less flexibility in the management of wild burros. After the appropriate management level for the Hickison Wild Burro Territory is determined, it would be timely to consider how to manage livestock in allotments that overlap the territory.
Mineral Exploration and Recreation No cumulative effects from mineral exploration, mining, and recreation are anticipated from the proposed action.
Determination The wild burro territory supports only several springs, most of which are developed for livestock use. These represent a minute fraction of the approximately 1,390 springs that are mapped within the Austin/Tonopah Ranger District. Although the proposed action could benefit spring habitats within the wild burro territory as well as springs and riparian habitats within the remainder of the analysis area, this alternative would not alter the existing trend in habitat nor would it lead to a change in the distribution of macroinvertebrates, across the entire Humboldt-Toiyabe National Forest.
Humboldt-Toiyabe National Forest 110 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Alternative 3
Direct and Indirect Effects Direct and indirect effects would be the same as those in alternative 2 – proposed action except with regard to improvements to habitats resulting from maintaining burros within the appropriate management level.
Improvements in habitat will be dependent on the success rate of treating burros with fertility control vaccines. Since the rate of success in applying vaccines is largely unknown, it is difficult to estimate the speed in which habitat would improve due to the subsequent reduction in burro population numbers. Habitat should improve in proportion to the rate of success in achieving the appropriate management level; that is, a decrease in burro population from current levels. Since it is expected that achieving the appropriate management level via application of fertility control vaccines would take longer than gathers proposed in alternative 2 – proposed action, subsequent improvements in habitat would also take longer.
Cumulative Effects In general, the cumulative effects of alternative 3 are the same as alternative 2 – proposed action.
Determination The wild burro territory supports only several springs, most of which are developed for livestock use. These represent a minute fraction of the approximately 1,390 springs that are mapped within the Austin/Tonopah Ranger District. Although alternative 3 may benefit spring habitats within the wild burro territory as well as springs and riparian habitats within the remainder of the analysis area, this alternative would not alter the existing trend in habitat nor would it lead to a change in the distribution of macroinvertebrates, across the entire Humboldt-Toiyabe National Forest.
Conservation Priority Migratory Bird Species Under the National Forest Management Act, the Forest Service is directed to “provide for diversity of plant and animal communities based on the suitability and capability of the specific land area in order to meet overall multiple-use objectives” (Public Law 94-588, section 6 (g) (3) (B)). The January 2000 USDA Forest Service Landbird Conservation Strategic Plan, followed by Executive Order 13186 in 2001, in addition to the Partners in Flight specific habitat conservation plans for birds and the January 2004 Partners in Flight North American Landbird Conservation Plan, all reference goals and objectives for integrating bird conservation into forest management and planning.
In late 2008, a memorandum of understanding between the USDA Forest Service and the U.S. Fish and Wildlife Service to promote the conservation of migratory birds was signed (USDA Forest Service and USDI Fish and Wildlife Service 2008). The intent of the memorandum of understanding is to strengthen migratory bird conservation through enhanced collaboration and cooperation between the Forest Service and the U.S. Fish and Wildlife Service as well as other Federal, State, Tribal and local governments. Within the national forests, conservation of migratory birds focuses on providing a diversity of habitat conditions at multiple spatial scales and ensuring that bird conservation is addressed when planning for land management activities. In early 2016, both Forest Service and U.S. Fish and Wildlife Service agreed to extend the memorandum of understanding as currently written.
Consistency with the 2008 Memorandum of Understanding The Humboldt-Toiyabe National Forest staff is proposing to manage lands on the Austin/Tonopah Ranger District. Proposed management is intended to implement direction in the 1986 Toiyabe forest plan (USDA Forest Service 1986). Consistency between the Hickison Wild Burro Territory project proposed
Humboldt-Toiyabe National Forest 111 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
action and applicable elements of the memorandum of understanding (section C, item 1 and section D, item 3) is described below.
Conservation Benefits to Migratory Birds The area of greatest overlap between wild burros and migratory birds within the analysis area most likely occurs in shrub and sagebrush communities. Managing wild burros within the upper and lower appropriate management level would help ensure grazing is kept at levels that sustain vegetative components of plant communities essential to migratory birds, especially during drought periods. Under the proposed action, rangeland conditions within shrub communities would be expected to improve and move away from the “functioning at risk” classification. Once the appropriate management level is achieved, mosaics of shrub cover, perennial grass cover, forb cover, bare ground, plant densities, and plant diversity may be achieved. As a result, seed production should increase, which would provide important food sources for several seed-eating migratory bird species. This mosaic could enhance migratory bird habitat throughout the wild burro territory and increase migratory bird species diversity and abundance within the analysis area. The increase in migratory bird species diversity could enhance avian predator foraging within the Hickison Wild Burro Territory.
Minimizing Impacts to Migratory Birds Population management actions are expected to be limited in duration and frequency and would cause minimal impacts to migratory birds. Some individual migratory birds may avoid bait stations, corrals, and holding facilities but would be expected to resume normal activities once gather operations cease. However, migratory birds could utilize artificial water sources used to bait trap wild burros. Therefore, artificial water sources at bait trapping locations would be designed to allow access and escape for migratory birds consuming water at these sites. For example, the artificial water source would have a lip wide enough for perching, a water level high enough for the birds to access the water, and properly designed escape ramps.
Helicopters may be used when bait trapping is ineffective, but they would not be the primary gather method. Their use is expected to be limited in duration and frequency. Since helicopter use is not expected to be concentrated in one particular area, disturbances to nesting and breeding birds are also expected to be temporary and short in duration.
Determination The action alternatives include design features that minimize potential impacts to migratory birds, consistent with the 2008 migratory bird memorandum of understanding. Note: further analysis of Golden eagle, a conservation priority migratory species, is provided in the following section.
Golden Eagle
Alternative 1—No Action
Direct and Indirect Effects Under the no-action alternative, wild burro populations within the wild burro territory are expected to increase. The wild burro’s ability to consume grasses, forbs, and shrubs year-round can alter the structure, production, and composition of plant communities, especially during drought periods. Since wild burros are not associated with golden eagle nesting habitat of steep cliffs, the no-action alternative would have no effect on golden eagle nesting habitat.
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Altered vegetative structure and decreased production and plant community composition associated with the no-action alternative could reduce golden eagle prey habitat (Jones and Longland 1999; Beever and Brussard 2004). Further, the excessive herbivory associated with the expanding wild burro populations could directly compete with golden eagle prey (jackrabbits and cottontails) for forage, potentially decreasing the rodent and rabbit population. Golden eagles depend on high-quality foraging habitats associated with their nest sites, so decreased prey abundance could negatively affect foraging habitat and decrease the suitability of breeding and nesting territories.
Cumulative Effects No cumulative effects from wild burro management outside the Hickison Wild Burro Territory, livestock grazing and range developments, mineral exploration, or recreation are anticipated from the no-action alternative.
Determination The no-action alternative may lead to short-term increases in golden eagle prey abundance due to higher shrub densities, but could also cause more long-term decreases in golden eagle prey species habitat suitability.
Alternative 2—Proposed Action
Direct and Indirect Effects Under the proposed action, managing wild burro populations at levels compatible with resource capabilities would improve golden eagle foraging habitat and its resiliency during drought conditions. Restoring healthy rangeland conditions could enhance golden eagle nesting and breeding territories by providing renewable prey populations. Since rabbit populations can be cyclic and contain boom and bust periods, improved rangeland conditions achieved by managing wild burro populations within the upper and lower appropriate management level could provide supplementary prey species, such as ground squirrels, during jackrabbit bust periods. Having a reliable prey source within a breeding and nesting territory could increase nestling survival rates in local golden eagle populations.
Population management actions are expected to be limited in duration and frequency and would cause minimal impacts to golden eagles. Foraging golden eagles are likely to avoid bait stations, corrals, and holding facilities during gather operations but are expected to resume normal activities once gather operations cease. Even though golden eagles are likely to avoid structures associated with gather operations, this species could utilize artificial water sources used to bait trap wild burros. Therefore, artificial water sources at bait trapping locations would be designed to allow access and escape for raptors consuming water at these sites. For example, the artificial water source would have a lip wide enough for raptors to perch, a water level high enough for them to access the water, and properly designed escape ramps.
Helicopters may be used when bait trapping is ineffective, but they would not be the primary gather method. Their use is expected to be limited in duration and frequency. To minimize disturbances to nesting golden eagles, the district wildlife biologist would be contacted for any necessary avoidance measures regarding gather operations taking place during golden eagle breeding and nesting dates (later January to August).
Cumulative Effects No cumulative effects from wild burro management outside the Hickison wild burro territory, mineral exploration, or recreation are anticipated from the proposed action.
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Livestock Grazing and Range Developments Livestock grazing is expected to impact vegetation in the analysis area similarly to the effects caused by wild burro grazing. Habitat for golden eagle prey species, such as jackrabbits, would be affected similarly by either type of grazing as high concentrations of grazing animals could decrease available forage resources. The impact of grazing is especially strong during drought cycles, which are common in central Nevada.
Decisions on livestock grazing would be addressed in future environmental analyses on the grazing allotments. This proposal was pursued first because there is less flexibility in the management of wild burros. After the appropriate management level for the Hickison Wild Burro Territory is determined, it would be timely to consider how to manage livestock in allotments that overlap the territory.
Determination The proposed action may cause short-term avoidance of bait and trap sites by golden eagles during gather operations, but would also potentially increase prey species abundance though improvements in habitat quality.
Alternative 3
Direct and Indirect Effects Direct and indirect effects would be the same as those in alternative 2 – proposed action except with regard to improvements to habitats resulting from maintaining burros within the appropriate management level.
Improvements in habitat will be dependent on the success rate of treating burros with fertility control vaccines. Since the rate of success in applying vaccines is largely unknown, it is difficult to estimate the speed in which habitat would improve due to the subsequent reduction in burro population numbers. In general terms, habitat should improve in proportion to the rate of success in achieving appropriate management level; that is, a decrease in burro population from current levels. Since it is expected that achieving the appropriate management level via application of fertility control vaccines would take longer than gathers proposed in alternative 2 – proposed action, subsequent improvements in habitat would also take longer.
Cumulative Effects In general, the cumulative effects of alternative 3 are the same as alternative 2 – proposed action.
Determination Alternative 3 may cause short-term avoidance of bait sites by golden eagles during gather operations, but would also potentially increase prey species abundance through improvements in habitat quality.
Pronghorn Pronghorn is a species of interest that occurs in the analysis area and is therefore analyzed in this section.
Alternative 1—No Action
Direct and Indirect Effects Under the no-action alternative, wild burro populations are expected to continuously increase. The wild burro’s ability to consume grasses, forbs, and shrubs increases the likelihood of altering the vegetative structure and composition of plant communities, especially during drought periods, when forage availability will be further decreased.
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Wild burros prefer grasses and forbs but opportunistically switch to shrubs when necessary. Pronghorn depend on high-quality browse and forbs to meet their nutritional requirements; they cannot switch their diet composition and subsist on low-quality forage the way wild burros can (Olsen and Hansen 1977; McInnis and Vavra 1987). When their preferred forage becomes limited, wild burros can subsist on species unsuitable to pronghorn; pronghorn, however, may become nutritionally stressed if they cannot find enough of the high-quality forage they require. As a consequence, wild burros may have a competitive advantage in highly variable, arid environments. This advantage is likely at work within the Hickison Wild Burro Territory: grasses are already infrequent and limited there, so wild burros may be relying more heavily on browse species in this area.
Wild burros have higher forage consumption rates than pronghorn, and excessive wild burro grazing can reduce the quality and quantity of forage and cover utilized by pronghorn. Since grasses and forbs are limited within the wild burro territory, diet overlap between wild burros and pronghorn is considerable, especially during winter. Wyoming big sagebrush, low sagebrush, ephedra, shadscale, and saltbush are most likely to be utilized by pronghorn and wild burros for food and cover during winter. Excess herbivory within these shrub communities may delay or prevent seed production and decrease plant vigor (Wambolt and Hoffman 2004). The continued loss and degradation of the pronghorn’s most important winter protein source (sagebrush) through excessive wild burro grazing could deprive pronghorn of their nutritional needs to an extent that would inhibit reproduction (that is, gestation, lactation, birth rates, and fawn rates).
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory Potential effects of the no-action alternative when added to past, present, and reasonably foreseeable future activities of wild burro management outside the Hickison Wild Burro Territory could accelerate pronghorn habitat loss and fragmentation within the analysis area, due to the escalating population of wild burros associated with the wild burro territory.
Livestock Grazing and Range Developments Livestock grazing within pronghorn habitat in the analysis area would be expected to cause impacts similar to those caused by wild burro grazing. Therefore, continuing to graze livestock at the same intensity as occurred historically, while wild burro populations continue to increase, could accelerate habitat loss and fragmentation within pronghorn habitat.
Mineral Exploration Mineral exploration projects are typically limited to a small area and with a short, typically 1-year, implementation window. Requirements for reclaiming and revegetating disturbed areas are normally required. Impacts are limited to a temporary displacement of pronghorn into other adjacent habitats. Due to the limited, short-term nature of mineral exploration projects, they are not considered cumulative with the increasing burro population resulting from alternative 1.
Development of permanent or long-term mines does have the potential to displace pronghorn from suitable habitats on a permanent or extended basis. This displacement in turn has the potential to further concentrate pronghorn and burros in the same areas. Since burros have a competitive advantage over pronghorn in foraging, deer would likely suffer from reduced foraging opportunities and subsequently reduced physical fitness and reduced survivability. As burro numbers increase under the no-action alternative and habitats continue to decline, the cumulative impact from other activities that impact foraging habitats would become more intense.
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Recreation No cumulative effects from recreation are anticipated from the no-action alternative.
Determination The no-action alternative would continue the existing trend of increased foraging competition and decreasing forage availability on pronghorn habitats within the analysis area.
Alternative 2—Proposed Action
Direct and Indirect Effects Under the proposed action, managing wild burro populations at levels compatible with resource capabilities would improve pronghorn habitat and its resiliency during drought conditions. Eliminating excessive wild burro grazing in pronghorn habitat can improve the sagebrush overstory and understory, which provides forage and screening cover.
Managing wild burro populations within the upper and lower appropriate management level would increase residual forage, stimulate leader growth on browse species, increase seed production, decrease hedging, and increase vigor of the sagebrush and salt desert scrub communities. Over time, grasses would be expected to increase in production and frequency. This increase in grasses could alleviate some of the competition for browse species between wild burros and pronghorn and increase screening cover, which is crucial for fawn survival.
Population management actions are expected to be limited in duration and frequency and would cause minimal impacts to pronghorn. Individual pronghorn that may be present in or near gather corrals, bait and water traps, or holding facilities could be temporarily displaced or might avoid the area. However, once gather operations cease in that area, these animals would likely return to normal activities. Helicopters may be used when bait trapping is ineffective, but they will not be the primary gather method. Helicopters have been used in the analysis area for other purposes, such as wildlife and wild burro census flights. Their use is expected to be limited in duration and frequency. Some pronghorn may flee but are expected to return to normal activities after the helicopter moves away. The analysis area has a low density of fences; pronghorn fence collisions from helicopter disturbances are very unlikely. Temporary gather corrals and bait stations may impact some vegetation by concentrating wild burros in a small area. However, the disturbed vegetation would likely recover, and the effects to pronghorn habitat would be negligible.
Cumulative Effects Wild Burro Management outside the Hickison Wild Burro Territory The combined potential effects of the proposed action along with the potential effects from the past, present, and reasonably foreseeable future activities of inside and outside the Hickison Wild Burro Territory could assist in maintaining the wild burro populations between the herd management area and wild burro territory at the appropriate management level. Maintaining the proposed appropriate management level for the wild burro population in an ecological balance with the rangeland could improve pronghorn habitat by increasing available forage, screening cover, and thermal cover during winter.
Livestock Grazing and Range Developments Effects of livestock grazing would be similar to those caused by wild burro grazing. High concentrations of grazing animals could fragment sage-grouse habitat; and decrease essential vegetation important for thermal cover in the winter, hiding cover (making sage-grouse less vulnerable to avian predators), and
Humboldt-Toiyabe National Forest 116 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment lekking habitat. The impact of grazing is especially strong during drought cycles, which are common in central Nevada.
Decisions on livestock grazing would be addressed in future environmental analyses on the grazing allotments. This proposal was pursued first because there is less flexibility in the management of wild burros. After the appropriate management level for the Hickison Wild Burro Territory is determined, it would be timely to consider how to manage livestock in allotments that overlap the territory.
Mineral Exploration Both minerals exploration and actual mine implementation have potential to impact pronghorn and their habitats. While the reduction of burro numbers through alternative 2 – proposed action would benefit pronghorn habitats, it is unlikely to interact cumulatively with mining activities to impact mule deer in either a positive or negative manner.
Recreation No cumulative effects from recreation are anticipated from the proposed action.
Determination The proposed action would benefit pronghorn habitat suitability by decreasing foraging competition with wild burros and increasing forage availability.
Alternative 3
Direct and Indirect Effects Direct and indirect effects would be the same as those in alternative 2 – proposed action except with regard to improvements to habitats resulting from maintaining burros within the appropriate management level.
Improvements in habitat would depend on the success rate of treating burros with fertility control vaccines. Since the rate of success in applying vaccines is largely unknown, it is difficult to estimate the speed in which habitat would improve due to the subsequent reduction in burro population numbers. Habitat should improve in proportion to the rate of success in achieving the appropriate management level; that is, a decrease in burro population from current levels. Since it is expected that achieving the appropriate management level via application of fertility control vaccines would take longer than gathers proposed in alternative 2 – proposed action, subsequent improvements in habitat would also take longer.
Cumulative Effects In general, the cumulative effects of alternative 3 are the same as alternative 2 – proposed action.
Determination Alternative 3 would benefit pronghorn habitat suitability by decreasing foraging competition with wild burros and increasing forage availability.
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Botanical Resources This section evaluates and discloses the potential effects of each alternative to botanical resources.
Affected Environment This analysis evaluates the potential impacts on two categories of species: 1) the Intermountain Region threatened, endangered, proposed, and sensitive species list (R4 list) that have the potential to occur on the Austin/Tonopah Ranger District (table 30) and 2) other rare species that have been identified by the Humboldt-Toiyabe National Forest botanist to be of management concern (watch list) (table 31). Species in the latter category have been evaluated by the Nevada Natural Heritage Program and assigned to the “Watch” or “At-Risk” lists. The botany report provides a detailed description of the analysis framework for plant species. Only those species known to occur, or potentially occurring, in or near the project area are analyzed.
An official list of threatened, endangered, and proposed species to consider during this analysis was obtained from the U.S. Fish and Wildlife Service Information for Planning and Consultation (IPaC) website on November 14, 2017, (USDI Fish and Wildlife Service 2017), Consultation Code 08ENVD00- 2018-SLI-0088. No threatened, endangered, or candidate plant species were identified.
Known or potentially occurring sensitive plant species (table 30) and other rare plant species (table 31) in the Austin/Tonopah Ranger District were further evaluated to determine their potential occurrence in or adjacent to the project area and areas used by wild burros. Humboldt-Toiyabe National Forest sensitive plants potentially present within or adjacent to the project area and in areas used by wild burros are Eastwood milkweed (Asclepias uncialis ssp. ruthiae (Asclepias eastwoodiana)), Toquima milkvetch (Astragalus toquimanus), upswept moonwort (Botrychium ascendens), dainty moonwort (Botrychium crenulatum), slender moonwort (Botrychium lineare), moosewort (Botrychium tunux), and dune beardtongue (Penstemon arenarius) (table 32).
Other rare plant (watch list) species potentially present within or adjacent to the project area and in areas used by wild burros are Callaway milkvetch (Astragalus callithrix), Torrey’s one-leaf milkvetch (Astragalus calycosus var. monophyllidus), cima milkvetch (Astragalus cimae var. cimae), starveling milkvetch (Astragalus jejunus var. jejunus), scorpion milkvetch (Astragalus lentiginosus var. scorpionis), squalid milkvetch (Astragalus serenoi var. sordescens), currant milkvetch (Astragalus uncialis), Beatley buckwheat (Eriogonum rosense var. beatleyae), Pahute green gentian (Frasera albicaulis var. modocensis (Frasera pahutensis)), rayless tansy aster (Machaeranthera grindelioides var. depressa), Candelaria blazingstar (Mentzelia candelariae), sand cholla (Opuntia pulchella), Watson spinecup (Oxytheca watsonii), Lahontan beardtongue (Penstemon palmeri var. macranthus), and chickensage (Sphaeromeria argentea) (table 33).
Table 30. Intermountain Region (R4), Humboldt-Toiyabe National Forest threatened, endangered, proposed, and sensitive plant species, and their known or potential presence within the Austin/Tonopah Ranger District. Nevada Natural Known or Heritage Program / Potentially Present NatureServe within Ranger Scientific Name Common Name Rankinga,b District Angelica scabrida Charleston angelica G2N2S2 No Antennaria soliceps Charleston pussytoes G1G2N1N2S1S2 No Arenaria kingii ssp. rosea Rosy King's sandwort G4T2QN2S2 No
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Nevada Natural Known or Heritage Program / Potentially Present NatureServe within Ranger Scientific Name Common Name Rankinga,b District Asclepias uncialis ssp. ruthiae Eastwood milkweed G3G4T3? NNRS3 Yes (Asclepias eastwoodiana) Astragalus aequalis Clokey milkvetch G2N2S2 No Astragalus johannis-howellii Long Valley milkvetch G2N2S2 No Astragalus oophorus var. Lee Canyon milkvetch G4T2N2S2 No clokeyanus Astragalus oophorus var. lavinii Lavin's egg milkvetch G4T2N2S1S2 No Astragalus remotus Spring Mountain milkvetch G2N2S2 No Astragalus toquimanus Toquima milkvetch G2N2S2 Yes Boechera (=Arabis) bodiensis Bodie Hills rockcress G2N2S2 No Boechera (=Arabis) nevadensis Spring Mountains rockcress G5T3T5N3N5SNR No (Arabis pendulina var. pendulina) Boechera (=Arabis) rectissima var. Washoe tall rockcress G4G5T1QN1S1 No simulans Boechera (=Arabis) rigidissima var. Galena Creek rockcress G3T2QN2S1 No demota Boechera (=Arabis) ophira Ophir rockcress G1N1S1S2 Yes Boechera (=Arabis) tiehmii Tiehm rockcress G2N2S1 No Botrychium ascendens Upswept moonwort G2G3N2N3S2S1 Yes Botrychium crenulatum Dainty moonwort G3N2N3S1S2S3 Yes Botrychium lineare Slender moonwort G2N2N2?S1S2S3 Yes Botrychium tunux Moosewort G2G3N1S1S2S3S Yes NR Carex tiogana Tioga Pass sedge G1N1S1 No Cusickiella quadricostata Bodie Hills draba G2N2S2 No Cymopterus goodrichii Goodrich biscuitroot G1N1S1 Yes Draba arida Desert whitlowgrass G2N2S2 Yes Draba asterophora var. Star draba G2T2N2S1S2 No asterophora Draba brachystylis Wasatch draba G1G2N1N2S1 No Draba jaegeri Jaeger draba G2N2S2 No Draba oreibata var. serpentina Snake Range G4T1N1S1 Yes whitlowgrass Draba paucifructa Charleston draba G1G2N1N2S1S2 No Epilobium nevadense Nevada willowherb G2N2S1S2 No Ericameria compacta Charleston Mountain G2?N2?S2? No (=Haplopappus compactus) goldenbush Eriogonum esmeraldense var. Toiyabe buckwheat G4T2N2S2 Yes toiyabense Eriogonum heermannii var. clokeyi Clokey buckwheat G5T2N2S2 No Eriogonum robustum Altered andesite buckwheat G2N2N3S2S3 No Glossopetalon clokeyi Clokey greasebush G2N2S2 No
Humboldt-Toiyabe National Forest 119 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Nevada Natural Known or Heritage Program / Potentially Present NatureServe within Ranger Scientific Name Common Name Rankinga,b District Glossopetalon pungens var. glabra Smooth dwarf greasebrush G2G3 T1Q S1 No (=G. pungens) Ivesia aperta var. aperta Sierra Valley ivesia G2T2N2S1S2 No Ivesia aperta var. canina Dog Valley ivesia G2T1N1S1 No Ivesia cryptocaulis Charleston ivesia G2N2S2 No Ivesia jaegeri Jaeger ivesia G2G3N2N3S2S3 No Ivesia sericoleuca Plumas ivesia G2G3N2N3S2S3 No Lesquerella hitchcockii var. Hitchcock’s bladderpod G3N3SNR No hitchcockii Meesia triquetra Three-ranked hump-moss G5NNRS1(Nevada) No Orthotrichum shevockii Shevock rockmoss G1N1S1 No Orthotrichum spjutii Spjut’s brittle-moss G1N1S1 No Penstemon arenarius Dune penstemon G2G3N2N3S2S3 Yes Penstemon leiophyllus var. keckii Charleston beardtongue G3T2N2S2 No Penstemon rubicundus Wassuk beardtongue G2G3N2N3S2S3 No Penstemon thompsoniae ssp. Jaeger beardtongue G4T2N2S2 No jaegeri Phacelia monoensis Mono phacelia G3N3S2S3 No Pinus albicaulis Whitebark pine G3G4N3N4 Yes Plagiobothrys glomeratus Altered andesite popcorn G2G3N2N3S2S3 No flower Poa abbreviata var. marshii Marsh’s bluegrass G5T2N2S1 Yes Polemonium chartaceum White Mountain skypilot G1N1S1 No Polyctenium williamsiae William’s combleaf G2QN2SNR No Senecio pattersonensis Mono ragwort G2N2S1S2 No Silene clokeyi Clokey’s catchfly G2N2S2 No Sphaeromeria compacta Charleston tansy G2N2S2 No Streptanthus oliganthus Masonic Mountain G2G3N2N3S2 No jewelflower Synthris ranunculina Charleston kittentails G2N2S2S3 No Tonestus (=Haplopappus) Alpine goldenweed G2N2S2 Yes alpinus Townsendia jonesii var. tumulosa Charleston ground daisy G4T3N3S3 No Trifolium macilentum var. Rollins’ clover G2G3QN2N3S2S3 Yes rollinsii Viola charlestonensis Charleston violet G3QN3S2S3 No aNatureServe ranking (NatureServe 2008), Species in bold are either known to occur or have the potential to occur on the Austin/Tonopah Ranger District. bG = Global, N = National, S = Sub-national, T = rank of a subspecies of an otherwise widespread and common species, Q = Questionable taxonomy that may reduce conservation priority, NR = Not Ranked, 1 = critically imperiled, 2 = imperiled, 3 = vulnerable, 4 = apparently secure, 5 = secure, ? = inexact numeric rank
Humboldt-Toiyabe National Forest 120 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Table 31. Other rare plant (watch list) species known or potentially present within the Austin/Tonopah Ranger District. NHHP/NatureServe Scientific Name Common Name Rankinga,b Agastache cusickii Cusick hyssop G3G4N3N4S2 Astragalus callithrix Callaway milkvetch G3N3S3 Astragalus calycosus var. monophyllidus Torrey’s one-leaf milkvetch G5T2QN2S2 Astragalus cimae var. cimae Cima milkvetch G2T2N2S2 Astragalus jejunus var. jejunus Starveling milkvetch G3T3N3S2? Astragalus lentiginosus var. scorpionis Scorpion milkvetch G5T3?N3?S3? Astragalus serenoi var. sordescens Squalid milkvetch G4T2N2S2 Astragalus uncialis Currant milkvetch G2N2S1S2 Boechera (Arabis) shockleyi Shockley’s rockcress G3N3S3 Cymopterus nivalis Elko spring-parsley G5N5S3 Eriogonum ovalifolium var. caelestinum Heavenly buckwheat G5T2T3N2N3S2S3 Erigeron cavernensis (Syn. E. uncialis ssp. Snake Mountain erigeron G3G4N3?S3? uncialis) Eriogonum rosense var. beatleyae Beatley buckwheat G4?NNRSNR Frasera albicaulis var. modocensis (Frasera Pahute green gentian G5T3T4NNRSNR pahutensis) Hackelia sharsmithii Sierran forget-me-not G2G3N2N3S2 Ipomopsis congesta var. nevadensis Toiyabe gilia G5T1N1S1 Jamesia tetrapetala Waxflower G2N2S2S1 Lepidium nanum Dwarf peppergrass G3N3S3 Machaeranthera grindelioides var. depressa Rayless tansy aster G5T3T4N3N4S3 Mentzelia candelariae Candelaria blazingstar G3?QN3?S3? Nevada (Smelowskia) holmgrenii Holmgren smelowskia G2G3N2N3S2S3 Opuntia pulchella Sand cholla G4NNRS2S3 Oxytheca watsonii Watson spinecup G3?N3?S3? Penstemon palmeri var. macranthus Lahontan beardtongue G4G5T2?N2?S2? Penstemon pudicus Bashful beardtongue G1S1N1 Silene nachlingerae Nachlinger’s catchfly G2N2S2 Sphaeromeria argentea Chickensage G3G4 N3N4S1? Sphaeralcea caespitosa var. williamsiae Railroad Valley globemallow G2T2NNRS2 aNatureServe ranking (NatureServe 2008) bG = Global, N = National, S = Sub-national, T = rank of a subspecies of an otherwise widespread and common species, Q = Questionable taxonomy that may reduce conservation priority, NR = Not Ranked, 1 = critically imperiled, 2 = imperiled, 3 = vulnerable, 4 = apparently secure, 5 = secure, ? = inexact numeric rank
Humboldt-Toiyabe National Forest 121 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Table 32. Austin/Tonopah District sensitive plant species potentially occurring in or adjacent to the project area Potentially Present Within Project Area in Areas Used by Wild Elevation Burros (Based on Habitat Species (feet) Community Habitat Description and Elevation) Asclepias uncialis ssp. 3,500- In open areas on a wide variety of Yes—The project area contains ruthiae (Asclepias 7,080 basic soils, generally barren and potential habitat for this species, eastwoodiana) lacking competition, frequently in including open areas that are Eastwood milkweed small washes or other moisture- generally barren and lacking accumulating microsites. Known competition on a wide variety of from the Ely (White Pine Range) basic soils within mixed desert and Austin/Tonopah Ranger shrub, sagebrush, and pinyon- Districts. Mixed desert shrub, juniper between 3,000 and 7,080 sagebrush, and pinyon-juniper. feet and small washes or other moisture-accumulating microsites. Astragalus toquimanus 6,480– Gravelly hillsides with gentle Yes—Although this species is Toquima milkvetch 7,520 slopes in basic or calcareous soils. known only from a very narrow Often growing up through geographic range limited to the Wyoming or black sagebrush southern ends of the Monitor and plants. Known from Tonopah Toquima mountain ranges, no in- Ranger District (only from S. depth surveys have been Toquima and S. Monitor). May– conducted to eliminate a broader June. Pinyon-juniper, sagebrush. distribution. The project area is within the documented elevation range of this species (6,480 to 7,520 feet). Sagebrush and pinyon- juniper communities on gentle slopes of basic or calcareous soils within the project area would represent potential habitat for Toquima milkvetch. Boechera (=Arabis) 9,960– Loamy soil pockets in dry, No—The project area lacks loamy ophira 10,520 exposed talus or scree, in rocky soil pockets in dry, exposed Ophir rockcress areas and outcrops on south- to quartzitic scree, colluvium, and west-facing ridgelines and upper outcrops on ridgelines and upper slopes, often in seasonal slopes; and mountain sagebrush solifluction areas. With Artemisia and subalpine conifer communities arbuscula, Leptodactylon between 9,960 and 10,520 feet. pungens, and grasses. Known Therefore, this project will have no only from the Toiyabe Range. impact on this species. June–July (late spring–summer). Mountain sagebrush, subalpine conifer, and alpine zones. Botrychium ascendens 8,891– Riparian, seeps, springs. Primarily Yes—Habitat parameters of moist Upswept moonwort 11,155 in in open habitats such as alpine ground in springhead areas in deep Nevada meadows, avalanche meadows, shade, or in wet to moist meadows and grassy roadsides. Probably with moss, grasses, sedges, and has some affinity for limestone or rushes, potentially exist within the other calcareous substrates. project area. Although the project Known locations from Spring area is more than 390 feet below Mountain National Recreation the documented elevation range of Area. Potential in Bridgeport, the species in Nevada, the species Carson, and Austin/Tonopah has not been thoroughly surveyed Ranger District. in the state, and its documented elevation range may not represent its potential elevation range.
Humboldt-Toiyabe National Forest 122 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Potentially Present Within Project Area in Areas Used by Wild Elevation Burros (Based on Habitat Species (feet) Community Habitat Description and Elevation) Botrychium crenulatum 8,200– Riparian, seeps, springs. Grows in Yes—Wet meadows, marshes, Dainty moonwort 11,150 in very moist sites with saturated soil bog-fen habitat types, and springs Nevada and dense herbaceous vegetation. potentially exist within the project Usually found at higher elevations area, and portions of the project in southern areas (most of area are within the documented Nevada). Probably has some elevation range of this species in affinity for limestone or other Nevada. Moreover, the species has calcareous substrates. Known not been thoroughly surveyed in the locations on Jarbidge Ruby state, and its documented elevation Mountains and Spring Mountain range may not represent its National Recreation Area; potential elevation range; therefore, potential across Humboldt- appropriate habitat below its Toiyabe National Forest. documented elevation range should be considered potential habitat. Botrychium lineare 8,497– Riparian, seeps, springs. High- Yes—High-elevation meadows, Slender moonwort 9,776 elevation meadows, seeps, and seeps, springs, roadsides, and roadsides. May be growing in soil riparian areas with limestone or or gravel. Probably has some other calcareous soil or gravel affinity for limestone or other substrates potentially exist within calcareous substrates. Potential the project area. habitat across the Humboldt- Toiyabe National Forest including the project area. Botrychium tunux 9,200– In Nevada, known from high- Yes—Sparsely vegetated alpine Moosewort 11,800 in elevation seeps and springs in the rock/talus/scree slopes and wet to CA and Spring Mountain National moist meadows with sandy soils are Nevada Recreation Area. Occurs in present within the project area. several disjunct areas, including Although the project area is below low-elevation coastal beaches and the documented elevation range of dunes in Alaska, well-drained this species in Nevada, the species rocky meadows in California, and has not been thoroughly surveyed in sparsely vegetated alpine scree the state, and its documented slopes in Montana, Wyoming, and elevation range may not represent Colorado. Potential across its potential elevation range. Humboldt-Toiyabe National Forest. Cymopterus goodrichii 7,300– Upper subalpine and lower alpine. No—Although a portion of the Goodrich biscuitroot 11,100 Found in shrub-forb communities project area is within the on slate and limestone talus documented elevation range of this slopes. Moderate to steep scree species (7,300 to 11,000 feet), the and talus slopes of dark angular project area does not include upper slate or limestone. Known from subalpine and lower alpine shrub- Austin-Tonopah Ranger District. forb communities on moderate to steep scree and talus slopes. Therefore, this project will have no impact on this species. Draba arida 7,350– Rock crevices, scree, snowbank No—Although a portion of the Arid draba 11,100 areas, rocky soils, loam, or forest project area is within the litter on gentle to steep slopes of documented elevation range of this all aspects. Often with limber pine species, the project area lacks (Pinus flexilis). Known from subalpine and lower alpine plant Austin-Tonopah Ranger District communities such as limber pine. (Toiyabe, Toquima, Monitor Therefore, this project will have no ranges). June–July. Subalpine impact on this species. conifer and lower alpine.
Humboldt-Toiyabe National Forest 123 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Potentially Present Within Project Area in Areas Used by Wild Elevation Burros (Based on Habitat Species (feet) Community Habitat Description and Elevation) Draba oreibata var. 10,000– Dry quartzite cliff crevices, ledges, No—Dry quartzite cliff crevices, serpentina 11,926 talus, and rocky slopes on all ledges, talus, and rocky slopes on Snake Range aspects. Known from Austin all aspects in lower alpine and upper whitlowgrass Ranger District; potential in Ely subalpine conifer between 10,000 and Tonopah Ranger Districts and 11,926 feet do not exist within (Snake, Toiyabe ranges). Lower the project area. Therefore, this alpine and upper subalpine project will have no impact on this conifer. species. Eriogonum 7,200– Found on generally steep, loose, No—Some of the project area is esmeraldense var. 9,240 sandy to gravelly or clay slopes within the documented elevation toiyabense derived from rhyolitic or andesitic range of this species, and steep Toiyabe buckwheat volcanic materials, frequently on slopes of loose, sandy to gravelly or white ash deposits. Known from clay derived from volcanic materials Austin/Tonopah Ranger District and white ash deposits potentially (all ranges). June–July (annual). exist within pinyon-juniper Pinyon-juniper, mountain communities in the project area. sagebrush, mountain mahogany, However, steep slopes and areas and subalpine conifer. with loose footing would be avoided by or receive only incidental use from the wild burros of the Hickison Wild Burro Territory. Therefore, this project will have no impact on this species. Penstemon arenarius 3,920– Deep, loose sandy soils of valley Yes—The lower end of the elevation Dune beardtongue 5,960 bottoms, aeolian deposits, and range of the project area is only 40 dune skirts, often in alkaline feet above the upper elevation areas, sometimes on road banks range documented for this species, and other recovering and the project area contains desert disturbances. Known from Stone shrub plant communities and deep Cabin and Big Smoky valleys, sandy soils. near the Tonopah Ranger District. Desert shrub. Pinus albacaulis 6,800– Dry, rocky sites and ledges and No—Although a portion of the Whitebark pine 10,750 in cliff faces in subalpine and alpine. project area is within the Nevada documented elevation range of this species, the area lacks the subalpine communities within which this species occurs. Therefore, this project will have no impact on this species. Poa abbreviata ssp. 11,600– Alpine. Found in soil pockets in No—The upper limit of the project marshii 12,600 alpine scree, talus, boulders, rock area is more than 3,100 feet below Marsh bluegrass fields, and loose quartzite. Known the known elevation range of this from Bridgeport and Ely Ranger species. Therefore, this project will Districts, but little survey has have no impact on this species. occurred.
Humboldt-Toiyabe National Forest 124 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Potentially Present Within Project Area in Areas Used by Wild Elevation Burros (Based on Habitat Species (feet) Community Habitat Description and Elevation) Tonestus 8,900– Crevices, rubble, and adjacent No—The project area is at least 400 (Haplopappus) alpinus 11,810 rocky soils of rock outcrops of feet below the elevation range of Alpine tonestus varied composition, often on this species and lacks the species’ northerly or protected aspects. documented habitat of crevices, Known from Austin/Tonopah rubble, and adjacent rocky soils of Ranger District (Toquima and rock outcrops in mountain Toiyabe; potential in all). June– mahogany, subalpine conifer, and August. Mountain mahogany, lower alpine communities. subalpine conifer, and lower Moreover, the wild burros in this alpine. area typically avoid steep slopes and areas with loose footing. Therefore, this project will have no impact on this species. Trifolium rollinsii 8,800– Dry to moist gravelly soils in No—The project area is at least 300 (Trifolium macilentum 10,580 concave, leeward, or other feet below the elevation range of var. rollinsii) moisture- and snow-accumulating this species and lacks the species’ Rollins’ clover areas on steep to moderate documented habitat of dry to moist slopes of all aspects in the gravelly soils in concave, leeward, mountain sagebrush, subalpine or other moisture- and snow- conifer, and lower alpine zones at accumulating areas on moderate to 8,800 to 10,570 feet in elevation. steep slopes in mountain Known from Austin/Tonopah sagebrush, subalpine conifer, and Ranger District (only from lower alpine communities. Toiyabe). June–July. Mountain Moreover, the wild burros in this sagebrush, subalpine conifer, and area typically avoid steep slopes lower alpine. and areas with loose footing. Therefore, this project will have no impact on this species.
Humboldt-Toiyabe National Forest 125 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Table 33. Austin/Tonopah District other rare plant species potentially occurring in or adjacent to the project area Nevada Natural Heritage Potentially Present Within Project Area Program Elevation in Areas Used by Wild Burros (Based Species Status (feet) Community Habitat Details and Distribution on Habitat Description and Elevation) Agastache cusickii Watch 5,000– Mountain Dry, open limestone slopes, often on No—Although the project area overlaps Cusick hyssop 11,000 sagebrush or talus slopes. Known from Austin the elevation range of this species, the mountain Ranger District. area lacks the mountain sagebrush and mahogany mountain mahogany communities that provide habitat for this species. Moreover, the wild burros in this area avoid steep slopes and areas with loose footing, so the burros would not be expected to impact sites occupied by this species. Therefore, this project will have no impact on this species. Astragalus callithrix Watch 4,880– Desert shrub Deep, sandy soil on the valley floor or Yes—The lower end of the elevation Callaway milkvetch 5,900 and on dunes in barren openings with range of the project area is only 100 feet sagebrush saltbush, Grayia, rabbitbrush, and above the upper elevation range sagebrush. Potential habitat on Ely and documented for this species, and the Austin-Tonopah Ranger Districts. project area contains desert shrub and sagebrush plant communities and deep soils. Astragalus calycosus At risk 5,250– Sagebrush or Found in lower foothills and valley Yes—The elevation range of the project var. monophyllidus 7,465 pinyon- habitats on dry, stony, or otherwise area overlaps the documented elevation Torrey’s one-leaf juniper barren places. Also in gravelly range of this species, and the project milkvetch openings in pinyon-juniper. Known from area contains sagebrush and pinyon- Austin/Tonopah (Toquima, Toiyabe; juniper communities. potential in all ranges) and Ely Ranger Districts. Astragalus cimae At risk 5,100– Desert shrub Dry, open, relatively barren calcareous Yes—The elevation range of the project var. cimae 6,416 and gravel slopes or clay hills. Known from area overlaps the documented elevation Cima milkvetch sagebrush Tonopah Ranger District (Monitor). range of this species, and the project area contains desert shrub and sagebrush communities. Astragalus jejunus Watch 5,740– Sagebrush to Dry, barren ridges, summits and bluffs, Yes—The project area overlaps the var. jejunus 7,310 pinyon- dry hilltops, gullied bluffs, and river- documented elevation range of this Starveling milkvetch juniper terraces, on tuff, shale, sandstone, species and contains sagebrush and cobble, or clays. May occur on the pinyon-juniper communities. Schoonover Formation.
Humboldt-Toiyabe National Forest 126 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Nevada Natural Heritage Potentially Present Within Project Area Program Elevation in Areas Used by Wild Burros (Based Species Status (feet) Community Habitat Details and Distribution on Habitat Description and Elevation) Astragalus Watch 6,075– Pinyon- Rocky crests, mountain meadows, and Yes—The project area overlaps the lentiginosus var. 11,000 juniper, brushy hillsides, mostly on limestone or documented elevation range of this scorpionis mountain limey clay soils from the upper edge of species and contains pinyon-juniper Scorpion milkvetch sagebrush, the sagebrush zone to near timberline. communities. and Known from Austin/Tonopah and Ruby subalpine Ranger Districts Astragalus serenoi Watch 5,040– Desert shrub, Dry, open, gravelly or sandy soils on Yes—The project area overlaps the var. sordescens 6,840 sagebrush, gentle slopes of alluvial fans or light- documented elevation range of this Squalid milkvetch and lower colored clay hills, frequently with black species and contains desert shrub, pinyon- sagebrush (Artemisia nova). Known sagebrush, and lower pinyon-juniper juniper from Tonopah Ranger District communities. Astragalus uncialis At risk 4,800– Desert shrub Knolls, gullied foothills, and stony Yes—The project area is within the upper Currant milkvetch 6,050 and washes, saline flats, gentle slopes of elevation range for this species and its sagebrush. hillsides and alluvial fans in calcareous typical habitat of desert shrub/sagebrush sandy-clay or gravelly alkaline soils. transitional plant community occurs within Potential habitat in Ely Ranger District. the project area. May–June. Boechera (Arabis) Watch 4,000– Desert shrub, Gravelly ridges and dry, rocky outcrops No—Although the project area overlaps shockleyi 8,600 sagebrush, of limestone, dolomite, and quartzite. the documented elevation range of this Shockley’s rockcress and pinyon- Known from Ely Ranger District. species and contains desert shrub, juniper sagebrush, and pinyon-juniper communities, the wild burros in this area typically avoid steep slopes and areas with loose footing. Therefore, this project will have no impact on this species. Cymopterus nivalis Watch 9,790– Subalpine Slopes and dry, rocky sites. Known No—The project area is at least 1,290 Elko spring-parsley 11,658 and alpine from the Toquima Range, with potential feet below the documented elevation to occur in all ranges on the range of this species and lacks subalpine Austin/Tonopah Ranger District. and alpine habitat. Therefore, this project will have no impact on this species. Eriogonum At risk 10,000– Upper Shallow rocky, gravelly, and sandy soils No—The project area is at least 1,500 ovalifolium var. 11,700 subalpine in exposed crest areas. Known from feet below the documented elevation caelestinum and alpine Austin/Tonopah Ranger District range of this species and lacks subalpine Heavenly buckwheat (Toiyabe and Toquima ranges). and alpine habitats. Therefore, this project will have no impact on this species.
Humboldt-Toiyabe National Forest 127 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Nevada Natural Heritage Potentially Present Within Project Area Program Elevation in Areas Used by Wild Burros (Based Species Status (feet) Community Habitat Details and Distribution on Habitat Description and Elevation) Eriogonum rosense At risk 5,500– Desert shrub, Dry volcanic outcrops. Known from Yes—The project area overlaps the var. beatleyae 9,280 Wyoming Bridgeport and Tonopah Ranger elevation range of this species and Beatley buckwheat sagebrush, Districts; potential in Austin Ranger contains desert shrub and pinyon-juniper pinyon- District (in all ranges). communities. juniper Erigeron uncialis var. At risk 10,000– Montane Endemic to White Pine County on No—Limestone cliffs and rubble and uncialis (E. 10,700 conifer and limestone cliffs and rubble in limber carbonate outcrops and crevices in cavernensi) subalpine pine and bristlecone pine communities. montane conifer and subalpine conifer Snake Mountain conifer zones Carbonate outcrops and crevices. communities between 10,000 and 10,700 erigeron Known from Ely Ranger District (Schell feet do not exist within the project area. Creek and White Pine ranges). Therefore, this project will have no impact on this species. Frasera albicaulis At risk 7,030– Pinyon- Relatively nonspecific habitats within Yes—The project area overlaps the var. modocensis 8,400 juniper, the pinyon-juniper and lower montane documented elevation range of this (Frasera pahutensis) mountain scrub zones, but most frequent in species and includes pinyon-juniper Pahute green gentian shrub relatively deep, stable, sandy or sandy- communities. rocky soils on or near protected exposures and in microdrainages, or on more open slopes at higher elevations. Known from all ranges on the Austin/Tonopah Ranger District. Hackelia sharsmithii Watch 7,200– Alpine, cliffs Talus slopes, fell fields, and rock- No—Although the project area overlaps Sierran forget-me-not 10,350 crevices near or above timberline or on the elevation range of this species, it cliffs at lower elevations (central lacks alpine habitat, and lower-elevation Nevada). Known from Austin/Tonopah cliffs potentially occupied by this species Ranger District. would not be accessible to wild burros. Therefore, this project will have no impact on this species. Ipomopsis congesta At risk 10,200 Mountain Occurs mostly in rocky clay carbonate No—The project area is at least 1,700 var. nevadensis sagebrush, soils or scree. Known from Austin feet below the documented elevation Toiyabe gilia subalpine Ranger District (endemic to Bunker Hill range of this species and lacks mountain conifer, and of the Toiyabe Range). sagebrush, subalpine conifer, and lower lower alpine alpine communities. Therefore, this project will have no impact on this species.
Humboldt-Toiyabe National Forest 128 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Nevada Natural Heritage Potentially Present Within Project Area Program Elevation in Areas Used by Wild Burros (Based Species Status (feet) Community Habitat Details and Distribution on Habitat Description and Elevation) Jamesia tetrapetala At risk 6,500– Pinyon- Occurs in the cracks and crevices of No—Some of the project area is within Waxflower 10,720 juniper to limestone outcrops and talus at cliff the documented elevation range of this subalpine bases. Known from Ely Ranger District species, and limestone outcrops and cliffs (Snake and Grant-Quinn ranges). and talus slopes at cliff bases within pinyon-juniper potentially exist within the project area. However, steep slopes and areas with loose footing would be avoided by or receive only incidental use from the wild burros of the Hickison Wild Burro Territory. Therefore, this project will have no impact on this species. Lepidium nanum Watch 6,440– Pinyon- Grows on dry, gravelly gypsum knolls No—Although the project area overlaps Dwarf peppergrass 6,560 juniper and of highly calcareous, tuffaceous soils. the documented elevation range of this sagebrush In Nevada, restricted to tufa mounds species and contains pinyon-juniper and around active or dormant hot springs. sagebrush communities, the habitat Known from Austin Ranger District occupied by this species would not be (Monitor/Hot Creek); potential in Ely accessible to wild burros. Therefore, this Ranger District. project will have no impact on this species. Machaeranthera Watch 5,000– Blackbrush, Carbonate or calcareous, nearly barren Yes—The project area overlaps the grindelioides var. 9,200 sagebrush, rocky, rocky clay, and clay soils on documented elevation range of this depressa pinyon- ridges, slopes, low hills, and badlands. species and includes sagebrush and Rayless tansy aster juniper, Known from Tonopah (Monitor/Hot pinyon-juniper communities that may mountain Creek) and Ely Ranger Districts. include areas with appropriate soils and mahogany, topography for this species. and lower subalpine conifer
Humboldt-Toiyabe National Forest 129 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Nevada Natural Heritage Potentially Present Within Project Area Program Elevation in Areas Used by Wild Burros (Based Species Status (feet) Community Habitat Details and Distribution on Habitat Description and Elevation) Mentzelia Watch 3,800– Desert shrub, Barren, often calcareous, low- Yes—The project area overlaps the candelariae 6,700 and competition gravelly or clay soils on documented elevation range of this Candelaria sagebrush weathered volcanic ash deposits, scree species and includes desert shrub and blazingstar slopes, hot spring mounds, washes, or sagebrush communities. road banks or other recovering disturbances. Potential in Austin/Tonopah Ranger District (Toquima, Toiyabe, Monitor/Hot Creek) and Bridgeport Ranger District (southern end). Nevada At risk 6,500– Lower alpine, Crevices, ledges, rubble, or small soil No—Although the project area overlaps (Smelowskia) 11,350 subalpine pockets on rock outcrops and cliffs, the documented elevation range of this holmgrenii conifer, from high-elevation ridges to north- species, the area lacks lower alpine, Holmgren mountain facing walls at lower elevations, on subalpine conifer, and mountain smelowskia sagebrush, various rock types. Known from sagebrush communities. In the pinyon- and upper Austin/Tonopah Ranger District juniper zone that occurs within the project pinyon- (Toiyabe, Toquima; potential in all). area, habitat for this species would not be juniper zones accessible to wild burros. Therefore, this project will have no impact on this species. Opuntia pulchella At risk 3,950– Desert shrub, Occurs in sand dunes, dry-lake Yes—The project area overlaps the Sand cholla 6,300 sand dunes borders, river bottoms, washes, valleys, documented elevation range of this and plains in the desert. Dependent on species and includes desert shrub sand dunes or deep sand in Nevada. vegetation. One occurrence of this Known from Austin/Tonopah Ranger species is documented from the project District. area. Oxytheca watsonii Watch 4,200– Desert shrub Dry, open, loose, and/or lightly Yes—The project area overlaps the Watson spinecup 6,530 disturbed, often calcareous, sandy soils documented elevation range of this of washes, roadsides, alluvial fans, and species and includes desert shrub valley bottoms. Known from Tonopah vegetation. Ranger District (Toiyabe, Toquima; potential in all); potential in Austin and Bridgeport Ranger Districts.
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Nevada Natural Heritage Potentially Present Within Project Area Program Elevation in Areas Used by Wild Burros (Based Species Status (feet) Community Habitat Details and Distribution on Habitat Description and Elevation) Penstemon palmeri At risk 3,428– Desert shrub, Washes, canyon floors, roadsides, Yes—The project area overlaps the var. macranthus 7,400 sagebrush particularly on calcareous substrate, documented elevation range of this Lahontan usually where subsurface moisture is species and includes desert shrub and beardtongue available. Known from the Monitor sagebrush communities. Range. Potential on all ranges. Penstemon pudicus At risk 7,500– Subalpine Crevices, soil pockets, and coarse No—A portion of the project area is within Bashful beardtongue 9,000 sagebrush, rocky soils of felsic volcanic outcrops, the documented elevation range of this mountain boulder piles, steep protected slopes, species, and crevices, soil pockets, and mahogany, and drainage bottoms, mostly on north coarse rocky soils of volcanic outcrops, and upper and east aspects boulder piles, steep protected slopes, and pinyon- drainage bottoms in upper pinyon-juniper juniper communities potentially exist within the zones. project area. However, the wild burros in this area would be expected to avoid or only incidentally utilize areas with steep slopes and loose footing within the elevation range of bashful beardtongue. Therefore, this project will have no impact on this species. Silene nachlingerea At risk 7,160– Subalpine Found on rocky limestone knolls and No—Although portions of the project area Nachlinger’s catchfly 11,250 conifer, ridges. Generally dry, exposed or are within the documented elevation mountain somewhat sheltered carbonate (rarely range of this species, subalpine conifer, mahogany quartzite) crevices in ridgeline outcrops, mountain mahogany, and mountain shrub talus, or very rocky soils on or at the communities with rocky limestone and bases of steep slopes or cliffs, on all quartzite knolls and ridges, outcrops, aspects but predominantly on talus, and very rocky soils on or at the northwesterly to northeasterly bases of steep slopes or cliffs do not exposures. With sparse Petrophytum occur within the project area. Moreover, caespitosum, Erigeron simplex, Pinus the wild burros in this area usually avoid flexilis, P. longaeva, Artemisia steep slopes and areas with loose arbuscula, Cercocarpus betuloides, footing. Therefore, this project will have Symphoricarpos oreophila, Leucopoa no impact on this species. nevadensis. Known from Austin/Tonopah, Ruby Mountains, Ely Ranger Districts (all ranges).
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Nevada Natural Heritage Potentially Present Within Project Area Program Elevation in Areas Used by Wild Burros (Based Species Status (feet) Community Habitat Details and Distribution on Habitat Description and Elevation) Sphaeralcea At risk 4,700– Desert shrub Found in sevy dolomite rock calcareous No—The lower limit of the project area is caespitosa var. 5,310 and soil. Appears to be restricted to a 690 feet above the upper elevation range williamsiae sagebrush. particular alluvial soil in Railroad Valley. for this species. Therefore, this project Railroad Valley Potential habitat in Ely Ranger District. will have no impact on this species. globemallow Sphaeromeria At risk 6,100– Pinyon- Dry, open, often rocky foothills; Yes—The project area overlaps the argentea 7,520 juniper moderately tolerant of alkali. Known documented elevation range of this Chickensage from Tonopah Ranger District. species and includes pinyon-juniper vegetation.
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Effects Analysis and Determinations for Humboldt-Toiyabe National Forest Sensitive Plant Species
Alternative 1—No Action
Direct and Indirect Effects In contrast with alternatives 2 and 3, the overall direct and indirect effects of the no-action alternative to sensitive plants would be greater since no activities would occur to manage wild burro herds at appropriate levels or address rangeland concerns. Potential direct effects would include trampling, which can result in direct mortality of individuals and loss of entire occurrences, and herbivory, which can result in direct mortality or reduced vitality and reproduction of individuals. These effects would be most likely in areas where burros concentrate.
Indirectly, concentrations of wild burros may lead to the loss and fragmentation of occupied habitat, the alteration of vegetation communities, the loss of pollinators, changes in seed set, the disruption of the seed bank, decreased plant vigor, increased weed density and distribution through the spread of weed propagules, and the spread of disease. Nonnative plants can spread quickly and affect the abundance and distribution of native plant species. Wild burros often function as vectors for the spread of noxious weeds and other invasive species. The spread of such plants can be particularly damaging to populations of sensitive plants because invasive species tend to outcompete natives. Infestation of certain weed species often shortens the fire return interval to a frequency that is too high to support sensitive species populations.
Cumulative Effects Cumulative effects under the no-action alternative would be similar to those of the action alternatives. Activities that may contribute to cumulative effects to sensitive plant species include wild burro management outside the Hickison Wild Burro Territory, livestock grazing and associated range developments, mineral exploration, recreation, and climate change. These activities are described in the section “Activities Considered in the Cumulative Effects Analysis for All Alternatives”.
Determinations After considering the direct, indirect, and cumulative effects described above for the no-action alternative, the following determinations have been reached for Humboldt-Toiyabe National Forest sensitive plants.
Eastwood milkweed (Asclepias uncialis ssp. ruthiae [Asclepias eastwoodiana]) No known occurrences of Eastwood milkweed exist within the Hickison Wild Burro Territory; however, considering the large size of the project area and its inclusion of potential habitat for this species, undiscovered small discrete populations may be present. Under the no-action alternative, no appropriate management level would be established, and no gathers would occur on National Forest System lands. The wild burro population would be allowed to grow, with the exception of gathers conducted by the Bureau of Land Management in the neighboring Hickison Herd Management Area or gathers to remove wild burros that have left the territory. Negative direct impacts to any populations of Eastwood milkweed on steep (greater than 30 percent) slopes would be unlikely because these areas are typically avoided by wild burros. Any Eastwood milkweed populations elsewhere in the project area would be subject to increased impacts associated with the growing population of wild burros. In contrast with the proposed action, the no-action alternative would not include a design feature to require sensitive plant surveys,
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appropriate sensitive plant avoidance, or other steps to reduce impacts from concentrated wild burro use. As a result, negative impacts to individuals and populations of Eastwood milkweed could occur if they occupy these areas of concentrated use. No known occurrences of Eastwood milkweed would be affected by the no-action alternative, and any potential impacts to small unknown populations would be unlikely to affect the viability of the species as a whole. Therefore, the no-action alternative may impact individuals or habitats of Eastwood milkweed but is not likely to result in a trend to Federal listing or loss of viability for this species.
Toquima milkvetch (Astragalus toquimanus) No known occurrences of Toquima milkvetch exist within the Hickison Wild Burro Territory; however, considering the large size of the project area and its inclusion of potential habitat for this species, discrete populations may be present. Under the no-action alternative, no appropriate management level would be established, and no gathers would occur on National Forest System lands. The wild burro population would be allowed to grow, with the exception of gathers conducted by the Bureau of Land Management in the neighboring Hickison Herd Management Area or gathers to remove wild burros that have left the territory. Because Toquima milkvetch occurs on gentle slopes, all areas of potential habitat would be subject to more than incidental use by wild burros and to the increased impacts associated with the growing wild burro population. In contrast with the proposed action, the no-action alternative would not include a design feature to require sensitive plant surveys, appropriate sensitive plant avoidance, or other steps to reduce impacts from concentrated wild burro use. As a result, negative impacts to individuals and populations of Toquima milkvetch could occur if they occupy these areas of concentrated use. No known occurrences of Toquima milkvetch would be affected by the no-action alternative, and any potential impacts to unknown populations would be unlikely to affect the viability of the species as a whole. Therefore, the no-action alternative may impact individuals or habitats of Toquima milkvetch but is not likely to result in a trend to Federal listing or loss of viability for this species.
Currant milkvetch (Astragalus uncialis) Potential habitat for currant milkvetch includes knolls, gullied foothills, stony washes, saline flats, and gentle slopes of hillsides and alluvial fans in calcareous sandy-clay or gravelly alkaline soils. Some of these areas have high potential for use by wild burros within the project area. Although currant milkvetch has not been documented in the project area, focused surveys have not been conducted there, and the possibility that populations of this species occupy habitat within the project area cannot be eliminated. Under the no-action alternative, no appropriate management level would be established, and no gathers would occur on National Forest System lands. The wild burro population would be allowed to grow, with the exception of gathers conducted by the Bureau of Land Management in the neighboring Hickison Herd Management Area or gathers to remove wild burros that have left the territory. In contrast with the proposed action, the no-action alternative would not include a design feature to require sensitive plant surveys, appropriate sensitive plant avoidance, or other steps to reduce impacts from concentrated wild burro use. As a result, negative impacts to individuals and populations of currant milkvetch could occur if they occupy these areas of concentrated use. No known occurrences of Toquima milkvetch would be affected by the no-action alternative, and any potential impacts to unknown populations would be unlikely to affect the viability of the species as a whole. Therefore, the no-action alternative may impact individuals or habitats of currant milkvetch but is not likely to result in a trend to Federal listing or loss of viability for this species.
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Upswept moonwort (Botrychium ascendens) Upswept moonwort is restricted to seeps, springs, riparian areas, and other wetland communities. No known occurrences of upswept moonwort exist within the Hickison Wild Burro Territory; however, considering the large size of the project area, the presence of potential habitat for this species within the project area, and the difficulty of detecting this species, discrete populations may be present. The wetland communities that constitute potential habitat for upswept moonwort would be likely to receive heavy use by wild burros. Under the no-action alternative, no appropriate management level would be established, and no gathers would occur on National Forest System lands. The wild burro population would be allowed to grow, with the exception of gathers conducted by the Bureau of Land Management in the neighboring Hickison Herd Management Area or gathers to remove wild burros that have left the territory. In contrast with the proposed action, the no-action alternative would not include a design feature to require sensitive plant surveys, appropriate sensitive plant avoidance, or other steps to reduce impacts from concentrated wild burro use. As a result, negative impacts to individuals or populations of upswept moonwort could occur if they occupy these areas of concentrated use. However, because of the widespread distribution of upswept moonwort, which includes Alaska, California, Minnesota, Montana, Nevada, Oregon, Wyoming, Alberta, British Columbia, Newfoundland, Ontario, Quebec, and Yukon (NatureServe 2013), such impacts would be unlikely to affect the viability of the species as a whole. Therefore, the N no-action alternative may impact individuals or habitats of upswept moonwort but is not likely to result in a trend to Federal listing or loss of viability for this species.
Dainty moonwort (Botrychium crenulatum) Dainty moonwort is restricted to seeps, springs, riparian areas, and other wetland communities. No known occurrences of dainty moonwort exist within the Hickison Wild Burro Territory; however, considering the large size of the project area, the presence of potential habitat for this species within the project area, and the difficulty of detecting this species, discrete populations may be present. The wetland communities that constitute potential habitat for dainty moonwort would be likely to receive heavy use by wild burros. Under the no-action alternative, no appropriate management level would be established, and no gathers would occur on National Forest System lands. The wild burro population would be allowed to grow, with the exception of gathers conducted by the Bureau of Land Management in the neighboring Hickison Herd Management Area or gathers to remove wild burros that have left the territory. In contrast with the proposed action, the no-action alternative would not include a design feature to require sensitive plant surveys, appropriate sensitive plant avoidance, or other steps to reduce impacts from concentrated wild burro use. As a result, negative impacts to individuals or populations of dainty moonwort could occur if they occupy these areas of concentrated. However, because of the widespread distribution of dainty moonwort, which includes Arizona, California, Idaho, Montana, Nevada, Oregon, Utah, Washington, Wyoming, British Columbia, Ontario, and Alberta (NatureServe 2017), such impacts would be unlikely to affect the viability of the species as a whole. Therefore, the no-action alternative may impact individuals or habitats of dainty moonwort but is not likely to result in a trend to Federal listing or loss of viability for this species.
Slender moonwort (Botrychium lineare) Slender moonwort typical habitat includes springs and seeps at 8,497 to 9,776 feet, however it has been documented from a wide variety of habitats, including limestone cliffs, gravelly beaches, and forest understory. No occurrences of slender moonwort have been documented in Nevada; however, considering the large size of the project area, the presence of potential habitat for this
Humboldt-Toiyabe National Forest 135 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
species within the project area, and the difficulty of detecting this species, small discrete unknown populations may be present. The wetland communities that constitute the species’ typical habitat would likely receive heavy use by wild burros. In contrast, drier upland sites, such as forest understory and cliffs, would be expected to receive little-to-no concentrated use by wild burros. Under the no-action alternative, no appropriate management level would be established, and no gathers would occur on National Forest System lands. The wild burro population would be allowed to grow, with the exception of gathers conducted by the Bureau of Land Management in the neighboring Hickison Herd Management Area or gathers to remove wild burros that have left the territory. In contrast with the proposed action, the no-action alternative would not include a design feature to require sensitive plant surveys, appropriate sensitive plant avoidance, or other steps to reduce impacts from concentrated wild burro use. As a result, negative impacts to individuals or populations of slender moonwort could occur if they occupy wetlands or other sites subject to concentrated use by wild burros within the project area. However, because of the widespread distribution of slender moonwort, which includes Alaska, California, Colorado, Idaho, Minnesota, Montana, Nevada, South Dakota, Utah, Washington, Wyoming, Alberta, British Columbia, New Brunswick, Quebec, and the Yukon Territory (NatureServe 2017), such impacts would be unlikely to affect the viability of the species as a whole. Therefore, the no- action alternative may impact individuals or habitats of slender moonwort but is not likely to result in a trend to Federal listing or loss of viability for this species.
Moosewort (Botrychium tunux) Moosewort is associated with seeps and springs at 9,200 to 11,800 feet in Nevada, but across its range, the species has been found on drier upland sites of rock, talus, and scree slopes. No occurrences of moosewort are documented within the Hickison Wild Burro Territory; however, considering the large size of the project area, the presence of potential habitat for this species within the project area, and the difficulty of detecting this species, discrete populations may be present. In Nevada, moosewort may occupy a wider variety of habitats, including dry upland sites, than it does in areas where the species is currently documented; therefore, all potential habitats were considered in this analysis. The wetland communities that constitute the species’ typical habitat in Nevada would likely receive heavy use by wild burros. In contrast, drier upland sites consisting of loose substrate on steep slopes would likely be avoided by wild burros. Under the no-action alternative, no appropriate management level would be established, and no gathers would occur on National Forest System lands. The wild burro population would be allowed to grow, with the exception of gathers conducted by the Bureau of Land Management in the neighboring Hickison Herd Management Area or gathers to remove wild burros that have left the territory. In contrast with the proposed action, the no-action alternative would not include a design feature to require sensitive plant surveys, appropriate sensitive plant avoidance, or other steps to reduce impacts from concentrated wild burro use. As a result, negative impacts to individuals or populations of moosewort could occur if they occupy wetland sites subject to concentrated use by wild burros in the project area. However, because of the widespread distribution of moosewort, which includes Alaska, California, Colorado, Idaho, Montana, New Mexico, Wyoming, Nevada, British Columbia, and the Yukon Territory (NatureServe 2017), such impacts would be unlikely to affect the viability of the species as a whole. Therefore, the no- action alternative may impact individuals or habitats of moosewort but is not likely to result in a trend to Federal listing or loss of viability for this species.
Dune beardtongue (Penstemon arenarius) Potential habitat for dune penstemon includes deep, loose sandy soils of valley bottoms, aeolian deposits, and dune skirts, often in alkaline areas, sometimes on road banks and other recovering
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disturbances. Such areas would be subject to use by wild burros within the project area. No known occurrences of dune penstemon exist within the Hickison Wild Burro Territory; however, considering the large size of the project area and its inclusion of potential habitat for this species, discrete populations may be present. Under the no-action alternative, no appropriate management level would be established, and no gathers would occur on National Forest System lands. The wild burro population would be allowed to grow, with the exception of gathers conducted by the Bureau of Land Management in the neighboring Hickison Herd Management Area or gathers to remove wild burros that have left the territory. In contrast with the proposed action, the no-action alternative would not include a design feature to require sensitive plant surveys, appropriate sensitive plant avoidance, or other steps to reduce impacts from concentrated wild burro use. As a result, negative impacts to individuals and populations of dune beardtongue could occur if they occupy these areas of concentrated use. No known occurrences of dune beardtongue would be affected by the no-action alternative, and any potential impacts to unknown populations would be unlikely to affect the viability of the species as a whole. Therefore, the no-action alternative may impact individuals or habitats of dune penstemon but is not likely to result in a trend to Federal listing or loss of viability for this species.
Alternatives 2 and 3
Direct and Indirect Effects The types of direct and indirect effects from alternatives 2 (proposed action) and 3 would be similar to those of the no-action alternative. Potential direct effects would include trampling during gather operations and particularly in areas where burros concentrate, which can result in direct mortality of individuals and loss of entire occurrences. However, in contrast with the no- action alternative, overall negative effects would decrease as the appropriate management level of 16 to 45 wild burros is achieved and design features are implemented.
Cumulative Effects Following is an analysis of past, present, and reasonably foreseeable future activities that may contribute to cumulative effects to botanical resources. A description of activities considered in this analysis is provided in the section “Activities Considered in the Cumulative Effects Analysis for All Alternatives”. Along with the direct and indirect effects identified above, cumulative effects may occur. These cumulative effects stem from human-related activities and some naturally occurring events that have affected, are presently affecting, and will continue to affect into the foreseeable future the populations and habitats of sensitive plant species within and outside the Hickison Wild Burro Territory. The cumulative effects analysis area for this document encompasses the direct and indirect effects analysis area, which consists of the project area buffered by 300 meters (984 feet), and any activity outside that area that could add to the direct and indirect effects of the alternatives. Past activities are considered part of the existing condition and are reflected in the preceding species accounts. In order to evaluate the contribution of past actions to the cumulative effects of the proposed action, this analysis relies on current environmental conditions as a proxy for the impacts of past actions. The reasoning behind this approach is that existing conditions reflect the aggregate impact of all prior human actions and natural events that have affected the environment and might contribute to cumulative effects.
Activities that may contribute to cumulative effects to sensitive plant species include wild burro management outside the Hickison Wild Burro Territory, livestock grazing and associated range
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developments, mineral exploration, recreation, and climate change. These activities and their effects are described below.
Wild Burro Management outside the Hickison Wild Burro Territory Though the magnitude and spatial distribution of potential impacts of wild horse and burro management on sensitive plants are different than those expected from livestock grazing (discussed below), the types of impacts are similar and include the following: trampling, which can result in direct mortality of individual plants and loss of entire occurrences; herbivory, which can result in direct mortality or reduced vitality and reproduction of individuals; alteration of habitat through soil compaction, which can reduce water infiltration and change hydrology and may render areas less suitable or unsuitable for sensitive plants; and increased competition for light, nutrients, and water through introduction or spread of nonnative invasive species, which may reduce sensitive plant species abundance or cause the loss of occurrences.
Livestock Grazing and Associated Range Developments Livestock grazing can impact sensitive plant species in a variety of ways. Individuals can be grazed upon, or they can be killed by crushing hooves (Atwood 1997; Morefield 2001). The placement of salt blocks can increase the salinity of soils to the point that soils are inhospitable for plants. Salt block locations and water features can increase soil compaction, which can damage the root zone of plants, inhibit water infiltration, change the pattern of runoff and sedimentation, and alter soil nutrient levels (Trombulak and Frissell 2000). Additional indirect effects of grazing and movement of livestock can include the following: increased dust deposition on leaves, which can disrupt proper physiological function; increased light exposure beyond the tolerance levels of some species; and disruption of pollinators, which can interfere with seed set, diminish seed banks (Kwak et al. 1998; Morefield 2001), and decrease recruitment of successive generations. Livestock can also introduce and spread invasive weeds that can outcompete individuals and even displace whole populations of sensitive plant species (Morefield 2001; Taylor et al. 2011; Wilcove et al. 1998).
Mineral Exploration Mineral exploration can affect sensitive plants directly and indirectly (Morefield 2001; Smith and Curto 1995). Individual plants can be crushed by foot traffic and the placement of equipment or killed during the removal of vegetation when sites are being cleared. Additional indirect effects of mineral exploration on sensitive plants can include the following: increased dust deposition on leaves, which can interfere with proper physiological function; increased light exposure beyond the tolerance levels of some species; and disruption of pollinators, which in turn can interfere with seed set, diminish seed banks (Kwak et al. 1998; Morefield 2001), and decrease the recruitment of successive generations. Mineral exploration also can introduce and spread invasive weeds, which can outcompete individuals and even displace entire populations of sensitive plant species (Morefield 2001; Taylor et al. 2011; Wilcove et al. 1998).
Recreation Dispersed camping can affect sensitive plants directly and indirectly (Holland 1999). Individual plants can be crushed by foot traffic and the placement of campers, tents, and other equipment; individual plants can be killed during the removal of vegetation when campsites are cleared. Potential indirect effects include soil compaction, which damages the root zone of plants, inhibits water infiltration, changes the pattern of runoff and sedimentation, and alters soil nutrient levels (Trombulak and Frissell 2000); increased dust deposition on leaves, which can disrupt proper physiological function; increased light exposure beyond the tolerance levels of some species; disruption of pollinators, which in turn can interfere with seed set, diminish seed banks (Kwak et
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al. 1998; Morefield 2001), and decrease the recruitment of successive generations; and introduction and spread of invasive weeds that can outcompete individuals and even displace populations of sensitive plant species (Taylor et al. 2011; Wilcove et al. 1998).
Hiking and hunting would be expected to create impacts similar to those caused by dispersed camping, but the effects would be broader in extent and lesser in degree. Anticipated impacts include trampling of plants, soil compaction, and introduction and spread of nonnative invasive plant species. Recreation encompasses a wide range of activities, most of which involve some form of overland travel (motorized or nonmotorized) and the use of roads, trail or both. Potential impacts of motorized travel associated with recreation would occur on authorized routes and would include dust generation and the introduction and spread of nonnative invasive plant species.
Climate Change Climate change models predict temperature increases of approximately 2.8 to 6.8 degrees Fahrenheit and a mean decrease in precipitation of approximately 4 percent by the middle of the 21st century in the basin-range area containing the Hickison Wild Burro Territory (Girvetz et al. 2009). Growing evidence indicates that climate change is affecting the distribution of many plant species and their habitats in numerous ways (Abbott and Le Maitre 2010; Anderson and Ferree 2010; Yates et al. 2010). For sensitive plant species that cannot effectively disperse to other areas or adapt quickly enough, climate change cause a loss of habitat and cause populations to become more vulnerable to stochastic events and local extirpation than they already are. Potential habitat for all sensitive plants within the project area could be affected by climate change, though changes may be the most pronounced for species such as the moonworts, which in Nevada are documented from small wetland areas that would be highly susceptible to loss due to increases in temperature and decreases in precipitation. The environmental assessment summarizes the potential effects of the alternatives on climate change (see Climate Change).
Determinations After considering the direct, indirect, and cumulative effects described above for the action alternatives, the following determinations have been reached for Humboldt-Toiyabe National Forest sensitive plants.
Eastwood milkweed (Asclepias uncialis ssp. ruthiae [Asclepias eastwoodiana]) This species has no slope restrictions for potential habitat. Therefore, all potential habitats for Eastwood milkweed within the project area on slopes less than 30 percent were analyzed. No known occurrences exist within the Hickison Wild Burro Territory; however, considering the large size of the project area, the possibility exists that potential habitats and small, discrete populations of Eastwood milkweed have been historically overlooked. In steeper areas, adverse impacts are less likely, as these areas are typically avoided by wild burros. In areas where wild burro activities are concentrated, design features implemented as part of the action alternatives would reduce or eliminate impacts such that there would be minimal to no effect on this species. Therefore, the action alternatives may impact individuals or habitats of Eastwood milkweed but are not likely to result in a trend to Federal listing or loss of viability for this species.
Toquima milkvetch (Astragalus toquimanus) Potential habitat for Toquima milkvetch is typically found on gentle slopes, where wild burros might also be found. Therefore, in every part of the project area where wild burro utilization is greater than incidental, all potential habitats for Toquima milkvetch were analyzed. No known occurrences of this species exist within the Hickison Wild Burro Territory; however, considering
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the large size of the project area, the possibility exists that potential habitats and small, discrete populations of Toquima milkvetch have been historically overlooked. In areas where wild burro activities are concentrated, design features implemented as part of the action alternatives would reduce or eliminate impacts such that there would be minimal to no effect on this species. Therefore, the action alternatives may impact individuals or habitats of Toquima milkvetch but are not likely to result in a trend to Federal listing or loss of viability for this species.
Upswept moonwort (Botrychium ascendens) Upswept moonwort is restricted to seeps, springs, riparian areas, and other wetland communities. No known occurrences exist within the Hickison Wild Burro Territory; however, considering the large size of the project area, the possibility exists that potential habitats and small, discrete populations of upswept moonwort have been historically overlooked. In areas where wild burro activities are concentrated, design features implemented as part of the action alternatives would reduce or eliminate impacts such that there would be minimal to no effect on this species. Therefore, the action alternatives may impact individuals or habitats of upswept moonwort but are not likely to result in a trend to Federal listing or loss of viability for this species.
Dainty moonwort (Botrychium crenulatum) Dainty moonwort is restricted to seeps, springs, riparian areas, and other wetland communities. No known occurrences exist within the Hickison Wild Burro Territory; however, considering the large size of the project area, the possibility exists that potential habitats and small, discrete populations of dainty moonwort have been historically overlooked. In areas where wild burro activities are concentrated, design features implemented as part of the action alternatives would reduce or eliminate impacts such that there would be minimal to no effect on this species. Therefore, the action alternatives may impact individuals or habitats of dainty moonwort but are not likely to result in a trend to Federal listing or loss of viability for this species.
Slender moonwort (Botrychium lineare) Slender moonwort typical habitat includes springs and seeps at 8,497 to 9,776 feet, however it has been documented from a wide variety of habitats, including limestone cliffs, gravelly beaches, and forest understory. Because slender moonwort is not limited to the typical wetland communities of most moonwort species, all potential habitats for this species were analyzed in every part of the project area where wild burro utilization is greater than incidental. No known occurrences exist within the Hickison Wild Burro Territory; however, considering the large size of the project area, the possibility exists that potential habitats and small, discrete populations of slender moonwort have been historically overlooked. In areas where wild burro activities are concentrated, design features implemented as part of the action alternatives would reduce or eliminate impacts such that there would be minimal to no effect on this species. Therefore, the action alternatives may impact individuals or habitats of slender moonwort but are not likely to result in a trend to Federal listing or loss of viability for this species.
Moosewort (Botrychium tunux) Moosewort is associated with seeps and springs at 9,200 to 11,800 feet in Nevada, but elsewhere within its range, the species is not limited to the typical wetland communities of most Botrychium species and has been found on drier upland sites of rock, talus, scree slopes. However, the drier upland sites’ steep slopes and loose or rocky footing are typically avoided by the wild burros of this area and were therefore eliminated from analysis. No known occurrences exist within the Hickison Wild Burro Territory; however, considering the large size of the project area, the possibility exists that potential habitats and small, discrete populations of moosewort have been historically overlooked. In areas where wild burro activities are concentrated, design features
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implemented as part of the action alternatives would reduce or eliminate impacts such that there would be minimal to no effect on this species. Therefore, the action alternatives may impact individuals or habitats of moosewort but are not likely to result in a trend to Federal listing or loss of viability for this species.
Dune beardtongue (Penstemon arenarius) Potential habitat for dune beardtongue includes deep, loose sandy soils of valley bottoms, aeolian deposits, and dune skirts, often in alkaline areas, sometimes on road banks and other recovering disturbances. Such areas would be subject to use by wild burros within the project area. Dune beardtongue has not been documented from the project area, and its known elevation range is at least 40 feet below the lower elevations in the project area. However, surveys for this species have not been exhaustive and have not focused on the project area. Until more complete surveys are done throughout all areas of potential habitat, the species’ documented elevation range should be considered approximate, and the possibility that populations of this species occupy habitat within the project area cannot be eliminated. Implementation of design features that would avoid direct impacts to sensitive plants from burro-concentrating activities and minimize indirect impacts associated with invasive species throughout the project area would ensure that impacts on this species would be negligible. Therefore, the action alternatives may impact individuals or habitats of dune penstemon but are not likely to result in a trend to Federal listing or loss of viability for this species.
Effects Analysis for other rare plant species Of the 28 other rare plant species, 15 have the potential to occur within portions of the project area used by wild burros (table 34). Potential effects are described below by alternative.
Alternative 1—No-Action Alternative
Direct, Indirect, and Cumulative Effects Under the no-action alternative, direct, indirect, and cumulative effects to district watch list species would be similar to those described for Humboldt-Toiyabe National Forest sensitive plants. In contrast with the action alternatives, the overall direct and indirect effects of the no- action alternative to these species would be greater since no activities would occur to manage wild burro herds at appropriate levels or address rangeland concerns. While addressing potential impacts to sensitive plants, design features implemented as part of the action alternatives would also avoid or minimize the impacts on district watch list species that share the same habitats. Without the implementation of these design features, the level of impacts to district watch list species would be expected to be higher under the no-action alternative.
Under the no-action alterative, potential impacts may occur to the following watch-list species: Callaway milkvetch, Torrey’s one-leaf milkvetch, cima milkvetch, starveling milkvetch, scorpion milkvetch, squalid milkvetch, Beatley buckwheat, Pahute green gentian, rayless tansy aster, Candelaria blazingstar, sand cholla, Watson spinecup, Lahontan beardtongue, and chickensage. Impacts to other district watch-list species are not expected.
Alternatives 2 and 3
Direct, Indirect, and Cumulative Effects Under alternatives 2 and 3, direct, indirect, and cumulative effects to district watch list species would be similar to those described for Humboldt-Toiyabe National Forest sensitive plants. In
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contrast with the no-action alternative, overall negative effects would decrease as the appropriate management level of 16 to 45 wild burros is achieved and design features are implemented. Design features that would avoid or minimize impacts on sensitive plants would benefit district watch list species by avoiding or minimizing direct and indirect impacts from activities that concentrate wild burro use and by reducing indirect impacts associated with invasive species throughout the Hickison Wild Burro Territory.
As with the no-action alternative, potential impacts may occur to the following watch list species under the action alternatives: Callaway milkvetch, Torrey’s one-leaf milkvetch, cima milkvetch, starveling milkvetch, scorpion milkvetch, squalid milkvetch, Beatley buckwheat, Pahute green gentian, rayless tansy aster, Candelaria blazingstar, sand cholla, Watson spinecup, Lahontan beardtongue, and chickensage. With the implementation of design features, any impacts on these species are expected to be minor. Impacts to other district watch list species would not be expected.
Summary of Findings and Conclusions No Intermountain Region (R4) threatened, endangered, proposed, or sensitive species list (table 30) occurrences are documented within the project area. Of the 16 species evaluated, the no- action alternative and alternatives 2 and 3 may impact individuals or populations but not likely to result in a trend to federal listing or loss of viability for populations of the following species: Eastwood milkweed (Asclepias uncialis ssp. ruthiae [Asclepias eastwoodiana]), Toquima milkvetch (Astragalus toquimanus), upswept moonwort (Botrychium ascendens), dainty moonwort (Botrychium crenulatum), slender moonwort (Botrychium lineare), moosewort (Botrychium tunux), and dune penstemon (Penstemon arenarius) (table 34).
Of the rare plant (watch list) species (table 31), only one occurrence of sand cholla (Opuntia pulchella) is documented within the project area. However, potential habitat for 14 additional rare plant species is present in the project area and in areas expected to receive more than incidental use by wild burros.
Table 34. Summary determinations for Intermountain Region threatened, endangered, proposed, and sensitive plant species with the potential to occur on the Austin/Tonopah Ranger District Potentially Present in Areas with Alternative Alternative Burro Utilization 1 No- 2 Higher than action Proposed Alternative Scientific Name Common Name Incidental Alternative Action 3 Asclepias uncialis Eastwood Yes MINT MINT MINT ssp. ruthiae milkweed (Asclepias eastwoodiana) Astragalus Toquima Yes MINT MINT MINT toquimanus milkvetch Boechera Ophir rockcress No NI NI NI (=Arabis) ophira Botrychium Upswept Yes MINT MINT MINT ascendens moonwort Botrychium Dainty moonwort Yes MINT MINT MINT crenulatum
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Potentially Present in Areas with Alternative Alternative Burro Utilization 1 No- 2 Higher than action Proposed Alternative Scientific Name Common Name Incidental Alternative Action 3 Botrychium lineare Slender moonwort Yes MINT MINT MINT Botrychium tunux Moosewort Yes MINT MINT MINT Cymopterus Goodrich No NI NI NI goodrichii biscuitroot Draba arida Desert No NI NI NI whitlowgrass Draba oreibata Snake Range No NI NI NI var. serpentina whitlowgrass Eriogonum Toiyabe No NI NI NI esmeraldense var. buckwheat toiyabense Penstemon Dune penstemon Yes MINT MINT MINT arenarius Pinus albicaulis Whitebark pine No NI NI NI Poa abbreviata Marsh’s bluegrass No NI NI NI var. marshii Tonestus alpine No NI NI NI (=Haplopappus) goldenweed alpinus Trifolium Rollins’ clover No NI NI NI macilentum var. rollinsii NI: No impact to individuals or populations of this species MINT: May impact individuals or populations but not likely to result in a trend to Federal listing or loss of viability for the populations of this species.
Social and Economic Resources This section evaluates and discloses the potential effects of each alternative to social and economic resources.
Affected Environment An analysis of existing social and economic conditions is necessary to establish the baseline from which to estimate potential consequences of project management actions. The following section analyzes current conditions and trends related to the social and economic environment of the study area, including demographic characteristics and local economic conditions. Table 35 presents resource indicators and measures used to define existing social and economic conditions.
The spatial boundaries for analyzing the direct and indirect effects to socioeconomics are limited to Lander and Eureka counties. These two counties best define where the greatest interactions between Forest Service resource management decisions related to Hickison Wild Burro Territory and the local economy will occur. Project activities will take place almost exclusively in Lander County. A small portion of the project area extends into Nye County; however, this area of Nye County is quite remote and economic activity is not expected to impact this area and, therefore, is not carried forward in the analysis.
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Table 35. Resource indicators and measures for the social and economic resources existing condition Resource Indicator Resource (quantify if Measure Element possible) (quantify if possible) Existing Condition Economic impact Economic activity Employment and labor Economic contributions by – project activities income from project Humboldt-Toiyabe National activities and recreation Forest in the surrounding viewing communities (IMPLAN 2015) Economic impact Economic activity Employment and labor Employment and labor – grazing income from grazing income supported from activities grazing on the Stoneberger and Toquima allotments. Financial Discounted values Present net value --- efficiency of costs and benefits Environmental Disproportionate Identification of low-income High and low poverty, justice and adverse effects and minority populations in unemployment, income to low-income the study area relative to Nevada and the and/or minority U.S. Presence of minority populations populations susceptible to management decisions. Recreation – Recreation use Qualitative discussion, Wildlife viewing related visits quality of life and values – wildlife national visitor use on the Humboldt-Toiyabe and economic impact viewing; economic monitoring – wildlife the local area. impact of wildlife viewing and visitation data viewing
Demographics Table 36 provides information on both population and demographics for the study area. In 2016, the total population for the planning area totaled 7,615 people. Lander County is the larger of the two counties, with a population of 5,946 (U.S. Department of Commerce 2016). Eureka County is one-third the size of Lander County and had a population of 1,669 in 2015 (U.S. Department of Commerce, 2016). The population of Nevada grew by nearly 50 percent from 2000 through 2015 (see table 36). In contrast, the population of Lander County and Eureka County grew by only 2.5 and 1 percent, respectively.
Austin is the closest community to the Hickison Wild Burro Territory and is classified as a census designated place by the U.S. Census Bureau. In 2010, the Austin census designated place population was 192 (U.S. Department of Commerce 2010). The closest community to the project area located in Eureka County is the Eureka census designated place. In 2010, the population of the Eureka census designated place was 610 (U.S. Department of Commerce 2010).
Also included in table 36 are data for Austin and Eureka census county divisions. These are county areas delineated for statistical purposes by the Census Bureau with cooperation from State, local, and Tribal officials (U.S. Department of Commerce 2012). Austin and Eureka census county divisions are approximately the lower half of Lander and Eureka counties. These data provide a more accurate representation of both the demographic and economic characteristics of the residents closest to the project area. This is particularly true for the Austin census county division, which is the lower half of Lander County. Only 12 percent of Lander County’s population lives in the Austin census county division, indicating the large portion of its
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population and employment opportunities are occurring in the northern half of the county, outside the economic area of influence for this project.
The study area is primarily non-Hispanic and white. Lander County has the largest population of Hispanic residents (21.1 percent), which is similar to Nevada as a whole. However, the Austin census designated place has a significantly smaller population of Hispanic residents compared to its respective county (9.4 percent). The Eureka census designated place, like its respective county, is also predominately non-Hispanic and white. Compared to Nevada as a whole, both Eureka and Lander counties have larger populations of American Indian residents; however, the population of American Indians located in the Austin and Eureka census county divisions is smaller than their respective counties. This indicates that the majority of American Indians reside in the northern portion of the Lander and Eureka counties, outside the project’s area of influence.
Table 36. Population and demographics Ethnicity Race % of total population % of total (2010) population(2010) Total Pop. Total Pop. Total Pop. Non- White American Other Two+ Area 2000 2010 2011-2015 Hispanic Hispanic Alone Indian Race Races Eureka 1,651 1,987 1,669 12.0 88.0 89.3 2.4 5.1 2.2 County Eureka 1103 1351 1,210 13.3 86.7 89.6 1.6 6.7 1.4 CCD Eureka N/A 610 N/A 11.6 88.4 89.5 2.8 4.4 1.8 CDP Lander 5,794 5,775 5,946 21.1 78.9 84.0 4.2 8.6 2.5 County Austin 468 528 689 13.4 86.6 89.4 0. 4 8.0 1.3 CCD Austin N/A 192 N/A 9.4 90.6 95.8 0.5 2.1 1.0 CDP Nevada 1,998,257 2,700,551 2,940,058 26.5 73.5 66.2 1.2 12.0 4.7 USA 281,421,906 308,745,538 316,515,021 16.3 83.7 72.4 0.9 6.2 2.9 Source: U.S. Department of Commerce 2000, 2010, 2016, CCD = census county division; CDP = census designated place; Pop. = population
Economic Characteristics Table 37 provides information on the study area’s economic well-being; data for Nevada and the United States are also provided for context. These data are an important consideration for forest planners because low-income individuals may be less able to adapt to changes in employment and income opportunities on the Humboldt-Toiyabe National Forest.
The median household income for the Eureka and Lander counties is higher than the state median. In 2015, median household income for Eureka was $13,000 higher than Nevada’s median, and Lander County’s median was $24,000 higher. Mining was the top industry in these counties, which was largely gold and ore mining, chemical and fertilizer extractions, as well as other nonmetallic minerals (IMPLAN 2015). Wages in mining are typically quite high; in these two counties, 57 percent of employment and 73 percent of income in 2015 was the attributed to the mining sector (IMPLAN 2015). While some residents of the Austin and Eureka census county
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divisions are employed in the mining sector (U.S. Department of Commerce 2016), most of the mining takes place in the northern portions of Eureka and Lander counties (Visher 2013). As such, the high county level median incomes are not necessarily representative of the incomes for the small communities of the Austin and Eureka census designated places. Available income data for these two census designated places is reported in the 2011-2015 American Community Survey (U.S. Department of Commerce, 2016), however, these data have a high margin of error ($30,000) and are not reliable. The median income for the Austin and Eureka census county divisions, while a larger area, are more reliable. In 2015, the reported median incomes for the census county divisions were $44,000 and $54,000, respectively (U.S. Department of Commerce 2016), similar to Nevada’s income level, and a better representation of the communities near the project.
The annual unemployment rate for Nevada is 5.7 percent, which is higher than the 2016 national average (4.9 percent). The unemployment rate for Eureka County is 4.6 percent, lower than both state and national averages. In contrast, the unemployment rate for Lander County is 6.2 percent, slightly higher than Nevada’s average. Unemployment data below the county level is not available. Table 37 also includes information on the poverty levels in the study area. Poverty is an indicator of economic well-being; in the study area poverty is below Nevada and U.S. averages.
Table 37. Economic characteristics Median Household Unemployment Rate Location Income (2015) (2016 Annual Average) Poverty Rate (2015) Eureka County $65,459 4.6% 9.5% Eureka CCD $54,333 N/A 9.5% Lander County $76,713 6.2% 10.8% Austin CCD $43,958 N/A 8.0% Nevada $52,544 5.7% 14.9% United States $55,775 4.9% 14.7% Source: Poverty data: Austin and Eureka census county divisions from U.S. Department of Commerce, Census Bureau ACS 2011-2015. All others from U.S Department of Commerce SAIPE, 2015; Unemployment data from Bureau of Labor and Statistics 2016; Median Income: Austin and Eureka census county divisions from ACS 2011-2015 all others from Census 2010. CCD = census county division
Economic Contribution of Livestock Grazing According to the need for change, wild burros are currently roaming outside the Hickison Wild Burro Territory and onto other public and private land, contributing to adverse grazing effects in some areas. Degraded rangeland conditions have also been documented on public grazing lands outside the Hickison Wild Burro Territory. Two range allotments, Stoneberger Basin and the Toquima Range, and three range permittees are located on or near the project area. A maximum of 1,939 animal unit months are permitted to graze in these areas annually. Only part of the Toquima Range allotment is impacted by burros (see “Rangeland Resources” section for more details). As such, 516 (of the 1,939) animal unit months are not impacted by management decisions. Therefore, 1,423 animal unit months are grazed in areas impacted by wild burros and management decisions.
Due to improved drought conditions, permittees were able to graze cattle at the maximum authorized animal unit months from 2014 to 2016. However, from 2003 through 2013, permittees were only grazing approximately 66 percent of the allowed animal unit months, and in 2017,
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permitted animal unit months were once again below the maximum authorized. This reduction was due to resource concerns including lack of forage and water, persistent drought conditions, and an abundance of burros. The growth in the burro population size is assumed to have increased utilization pressure above the levels of use that existed when the wild burro territory was created; burro population growth is also assumed to have contributed to undesirable vegetation condition. For more information, see the “Rangeland Resources” section.
When the maximum permitted animal unit months (1,423) are able to graze, 2 jobs and $67,000 in labor income are supported annually. If only 66 percent are able to graze, due to a host of reasons, (for example, overgrazing from burros or drought), 2 jobs and $44,000 in labor income would be supported annually.
Environmental Justice Executive Order 12898 requires Federal agencies to consider impacts of proposed actions on minority and low-income populations. Environmental justice refers to the fair treatment and meaningful involvement of people of all races, cultures, and incomes with respect to the development, implementation, and enforcement of environmental laws, regulations, programs, and policies.
According to the Council on Environmental Quality’s environmental justice guidelines for the National Environmental Policy Act (1997) “minority populations should be identified where either: (a) the minority population of the affected area exceeds 50 percent or (b) the minority population percentage of the affected area is meaningfully greater than the minority population percentage in the general population or other appropriate unit of geographic analysis.” Eureka and Lander Counties are less diverse than Nevada as a whole. Additionally, the communities of Austin and Eureka are less diverse than their respective counties, as described in the “Demographics” section above. As such, the potential for management actions to disproportionately and adversely affect minority individuals is low.
Council on Environmental Quality guidance on identifying low-income populations states “agencies may consider as a community either a group of individuals living in geographic proximity to one another, or a set of individuals (such as migrant workers or Native Americans), where either type of group experiences common conditions of environmental exposure or effect.”
Lander and Eureka Counties’ economic well-being as a whole is equal to or better than Nevada’s, in terms of income, unemployment, and poverty. Data available on the small communities directly surrounding the project area are limited. However, it is likely that residents of these smaller communities are less likely to work in the mining sector and thus have lower incomes (see “Economics Characteristics” section above). Whether or not these communities meet the threshold to be considered a low-income populations cannot be adequately determined. Therefore, low-income populations are assumed to exist in the project area and are considered in the effects analysis.
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Values, Beliefs, and Attitudes Public comments provided insight into the values, attitudes, and beliefs of the Hickison wild burro management area residents and surrounding communities. Commenters were concerned with how the herd reductions would impact the ability to view the wildlife.
1. Values are “relatively general, yet enduring, conceptions of what is good or bad, right or wrong, desirable or undesirable.” 2. Beliefs are “judgments about what is true or false – judgments about what attributes are linked to a given object. Beliefs can also link actions to effects.” 3. Attitudes are “tendencies to react favorably or unfavorably to a situation, individual, object, or concept. They arise in part from a person’s values and beliefs regarding the attitude object” (Allen et al. 2009). According to the national visitor use monitoring survey (USDA Forest Service 2011), only 1.9 percent of visitors indicated they participated in wildlife viewing while visiting the Humboldt- Toiyabe National Forest, and no visitors reported wildlife viewing as their main activity. The existing wild burro herd is not easy for visitors to find and view. Rather, the wild burros have wandered well outside the territory in search of forage and water. Allowing the herd size to grow may improve visitors’ chances of viewing wild burros in and outside the territory. However, the herd size has grown from 8 wild burros in 1995 to its current population of 126, and the wild burros are still difficult to find for viewing. Wildlife viewing, and subsequently wild burro viewing, provides a very little economic contribution to the small communities surrounding the Hickison Wild Burro Territory.
Environmental Effects
Alternative 1 – No-Action Under the no-action alternative, the appropriate management level for the territory would not change, and burro gathers would not be conducted on National Forest System lands. The wild burro herd would continue to grow; its population would be controlled by gathers off National Forest System lands and by natural forces. At 126 head (based on 2017 census data), the herd is pioneering far outside the territory. That behavior would be expected to continue under this alternative. Direct and indirect effects of alternative 1 are described below and summarized in table 38.
Direct and Indirect Effects
Economic Impact – Project activities No contractors would be hired to conduct gathers on the Humboldt-Toiyabe National Forest, so no related goods or services would be purchased in the surrounding communities (for example, food, gas, supplies). Accordingly, these communities would not receive any economic activity from gather activities on National Forest System lands.
Economic Impact - Grazing Negative impacts may be experienced by permittees grazing in the area under the no-action alternative. If the Hickison herd were to continue to grow unmanaged, forage and grazing conditions in the project area would likely deteriorate. In response, permittees may choose to substitute private for public forage or reduce their herd size. If permittees were to reduce herd size to zero, 2 jobs and $67,000 in labor income would be lost. If permittees substitute private
Humboldt-Toiyabe National Forest 148 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment forage for public forage they may experience economic losses from the higher costs of private forage, losses in management efficiency, or both.
Financial Efficiency There are no direct financial costs or benefits to the agency associated with the no-action alternative.
Environmental Justice The no-action alternative is not anticipated to impact members of an environmental justice community, unless members of an environmental justice community are directly involved in grazing activities surrounding the project area. If current or future grazing permittees are members of an environmental justice community,3 or if the growing herd roams further onto private lands where members of an environmental justice community are grazing their animals, then alternative 1 has the potential to negatively impact members of these communities. These negative impacts would result from degraded forage conditions that occur as a direct result from a growing burro population, which may create economic losses as described under Economic Impact – Grazing above. Low-income populations would have the most difficulty bearing these losses.
Recreation – Quality of Life and Economic Impact Under the no-action alternative, the burro herd will likely continue to grow beyond its current population. Despite a larger population, it is likely the burros will remain difficult to locate and view. As discussed under the affected environment, wild burro viewing provides very little recreation related economic contribution to the communities near the territory. Therefore, even if visitation to this area increased, economic impact from wildlife viewing in the area is unlikely to measurably grow. However, if the burro population becomes easier to view as a result of unmanaged population growth, it may improve quality of life for visitors who do visit to view the herd.
Table 38. Resource indicators, measures, and effects for alternative 1 Resource Indicator Measure Alternative 1 Resource Element (quantify if possible) (quantify if possible) Direct and Indirect Effects Economic impact Economic activity Employment and labor income No impact from project activities Economic impact Economic activity Employment and labor income Negative impact. A larger burro from grazing activities herd would continue to negatively impact grazing and forage conditions, limiting the available resources for permittees. As a result, permittees may reduce herd size or have to substitute for private forage. Increasing costs and reducing management efficiency. Potential loss of 2 jobs and $67,000 in labor income.
3 Demographic information about permittees is not gathered by the Forest Service.
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Resource Indicator Measure Alternative 1 Resource Element (quantify if possible) (quantify if possible) Direct and Indirect Effects Financial efficiency Discounted values of Present net value No impact. There are no costs costs and benefits associated with the no-action alternative, therefore there are no cost versus benefits to weigh. Environmental Disproportionate and Identification of low income Possible negative economic justice adverse effects to and minority populations in the impacts on members of an low-income study area environmental justice populations, minority community if grazing populations, or both permittees are members of an environmental justice community, or if the growing herd roams further into areas grazed by members of an environmental justice community. Quality of life and Recreation use values Qualitative discussion, national Marginal impact. If visitation to economic impact – wildlife viewing; visitor use monitoring – wildlife this area increased, economic economic impact of viewing and visitation data impact from recreation wildlife viewing visitation to view burros on the Humboldt-Toiyabe is unlikely to measurably grow. It is likely the burros would remain difficult to locate and view. However, if the burro population becomes easier to view as a result of unmanaged population growth, it may improve quality of life for visitors in search of the herd.
Cumulative Effects
Past, Present, and Reasonably Foreseeable Activities Relevant to Cumulative Effects Analysis Past, present, and reasonably foreseeable activities on the Humboldt-Toiyabe National Forest and adjacent Bureau of Land Management and private lands may combine with the effects of this project and impact socioeconomic resources. These activities include wild burro herd management on adjacent Bureau of Land Management lands, including nuisance gathers, and range improvement and restoration activities on allotments in the project area.
Economic Impact – Project activities Spending to conduct herd reduction and gather activities on adjacent Bureau of Land Management lands will support jobs and labor income, similar to the proposed action for this project. Based on available information, it is not possible to quantify jobs and labor income due to Bureau of Land Management wild burro herd management activities.
Economic Impact – Grazing Bureau of Land Management gathers may improve grazing conditions on and off the Bureau of Land Management herd management area. How these gathers will improve forage conditions on the range allotments directly impacted by the project is difficult to glean; however, negative impacts to forage conditions are not anticipated due to nuisance gathers.
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Range restoration and improvements, including noxious weed treatments, integrated pest management, fencing maintenance, and water developments that have and will continue to occur may increase the chances that permittees are able to graze the maximum authorized animal unit months and improve efficiency and management of their herds. However, it is uncertain if the benefits from these activities will exceed the negative impacts of the wild burros’ unmanaged population growth and the degraded forage conditions that may occur under the no-action alternative.
Environmental Justice Bureau of Land Management gathers will impact the same communities as those described in the affected environment section of this report. These gathers may negate some of the negative impacts to range conditions that occur as a result of a growing wild burro herd. In turn, reducing the possibility that burro herds will impact environmental justice communities employed in grazing.
Recreation – Wildlife Viewing: Quality of Life and Economic Impact A reduction in burros on Bureau of Land Management lands surrounding the Humboldt-Toiyabe National Forest may make it more difficult to find and view burro herds despite the no-action alternative allowing the herd to grow unmanaged. As discussed under the affected environment, wild burro viewing provides a very little economic contribution to the communities near the territory. Therefore, it is unlikely that reducing burros on adjacent lands will have measurable economic impacts. If gathers on Bureau of Land Management lands reduced the quality of life for visitors interested in viewing burros, then a larger herd on adjacent National Forest System lands may improve quality of life for these visitors.
Alternative 2 – Proposed Action The objective of the proposed action is to maintain the wild burro population associated with the Hickison Wild Burro Territory in a thriving natural ecological balance. The proposed action would include establishing lower and upper appropriate management level (16 to 45 wild burros), authorize population management actions, establish design criteria to resolve potential conflicts, and approve an adaptive management process based on monitoring. Direct and indirect effects of the proposed action are described below and summarized in table 39. The temporal boundaries for analyzing the direct and indirect effects is 25 years, from 2018 through 2043. Project activities described in each alternative are expected to continue, and to impact the study area past 2043, however, it is difficult to predict the scale of impacts and project needs beyond 25 years.
Direct and Indirect Effects
Economic Impact – Project activities Overall, the proposed action is anticipated to provide minor economic benefits. Project activities under alternative 2 would support a total of 35.5 jobs and $949,700 in labor income over 25 years, approximately 1.4 jobs and $38,000 in labor income annually. These jobs would occur sporadically over a 25-year period as bait, trap, sale, short- and long-term holding activities occur, estimated to be every 5 years.
Jobs and income presented here are occurring primarily in the industry for support activities for agricultural. Indirectly, project spending supports employment in transportation, assorted retail and hospitality sectors, trade, and engineering. Note that employment and income estimates provided above are not new jobs created in the local economy, rather, project activities will support employment and income in the sectors listed above.
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Contracting costs used to determine job and labor income estimates are the maximum anticipated. This means that job and labor income values are the upper bound, actual costs may be lower, in which case, job and labor income estimates would also be lower. Actual management needs may vary based on the local conditions and herd size, which may change spending and thus, job and labor income estimates.
Economic Impact – Grazing The proposed action is anticipated to have minor positive impacts to members of the local grazing community. Reducing the herd size within the appropriate management level range would help maintain rangeland forage in satisfactory conditions for continued grazing. If a reduction in herd size within the appropriate management level range supports the continued grazing of maximum animal unit months, 2 jobs and $67,000 in labor income would be supported annually. Range conditions would vary based on a number of factors (for example, drought), which might prohibit maximum grazing despite a reduction in burros.
Financial Efficiency The total cost of project activities under the proposed action is $1,571,500 for the 25-year period this report analyzes. The present net value for project activities (discounted 4 percent over 25 years) is $(1,173,446). There are no monetary benefits associated with the project; therefore, the present net value is a large negative value. While the benefits are not monetarily quantifiable, they would still exist. For example, a smaller burro population may lead to improved range conditions which would support jobs and income for local ranchers.
Recreation – Quality of Life and Economic Impact As described in the affected environment, there is very little visitation to the Humboldt-Toiyabe for the purpose of wildlife viewing. Reducing the herd’s size might make it more difficult to find and view; however, visitation for this purpose is limited and it is unlikely a smaller herd would have a measurable impact to visitation in the area. Economic impacts from reduced visitation would be marginal and difficult to measure. If the herd size does become more difficult to view, it may reduce quality of life for those visitors who enjoy viewing the herd.
Environmental Justice There would be no negative impact to members of an environmental justice community. If jobs and labor income resulting from project spending are absorbed by low-income and minority populations, project activities may benefit members of these communities.
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Table 39. Resource indicators and measures for alternative 2 direct and indirect effects Resource Indicator Resource (quantify if Measure Alternative 2 Element possible) (quantify if possible) Direct and Indirect Effects Economic impact – Economic activity Employment and labor Minor economic benefits. project activities income Annually, 1.4 jobs and $38,000 in labor income would be supported from project spending, for a total of 35.5 jobs and $949,700 in labor income over 25 years. Economic impact – Economic activity Employment and labor Minor positive impacts, if grazing income improved range conditions from herd reduction continues to support maximum animal unit months, then 2 jobs and $67,000 in labor income would be supported annually. Financial efficiency Discounted values of Present net value Present net value costs and benefits $(1,173,446) Environmental Disproportionate and Identification of low income No negative impacts to justice adverse effects to and minority populations in members of an low-income the study area environmental justice populations, minority community are anticipated. populations, or both Project spending has the potential to provide economic benefits to the environmental justice community if jobs and income are absorbed by members of these communities. Quality of life Recreation use Qualitative discussion, Marginal negative impact. values – wildlife national visitor use Reducing herd size within viewing monitoring – wildlife viewing the appropriate and visitation data management level range would make it more difficult to find and view the herd – reducing quality of life for visitors. Visitation for this purpose is limited and it is unlikely that a reduced herd size would have a measurable impact to visitation or to the economy.
Cumulative Effects
Past, Present, and Reasonably Foreseeable Activities Relevant to Cumulative Effects Analysis Past, present, and reasonably foreseeable activities on the Humboldt-Toiyabe National Forest and adjacent Bureau of Land Management and private lands may combine with the effects of this project and impact socioeconomic resources. These activities include wild burro herd
Humboldt-Toiyabe National Forest 153 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment management on adjacent Bureau of Land Management lands, including nuisance gathers, and range improvement and restoration activities on allotments in the project area.
Economic Impact – Project activities The economic impacts from Bureau of Land Management gather activities would be similar to those described under alternative 2 – direct and indirect effects. Based on available information, it is not possible to determine job and income values, however, these impacts would be positive and greater than those described under alternative 2.
Economic Impact – Grazing Bureau of Land Management gathers may improve grazing conditions on and off the Bureau of Land Management herd management area. How these gathers would improve forage conditions on the range allotments directly impacted by the project is difficult to glean; however, the cumulative impacts of Bureau of Land Management and Forest Service burro population reductions on range and forage conditions would be greater than if one project were implemented alone.
Range restoration and improvements, including noxious weed treatment, integrated pest management, fencing maintenance, and water developments that have occurred and will continue to occur, in conjunction with burro reductions, would likely improve forage conditions beyond what would occur if one project were implemented alone. These activities may increase the chances that permittees are able to graze the maximum authorized animal unit months and improve efficiency and management of their herds.
Environmental Justice Bureau of Land Management gathers would impact the same communities as those described in the affected environment section of this report. Cumulatively, Bureau of Land Management and Forest Service herd reduction measures may provide greater benefits to environmental justice communities than those described under alternative 2 – direct and indirect effects, if employment and income is absorbed by members of these communities. Cumulatively, these gathers would further limit the areas impacted off established territories (for example, private lands), further reducing the possibility that burro herds would impact members of an environmental justice community.
Recreation – Quality of Life and Economic Impact Cumulatively, a reduction in burros on Bureau of Land Management and National Forest System lands may make it more difficult to find and view burros than if only one agency reduced the burro population. As discussed under the affected environment, wild burro viewing provides a very little economic contribution to the communities near the territory. It is unlikely that reducing burros on both Bureau of Land Management and National Forest System lands would have measurable economic impacts from reduced visitation. Quality of life for those visitors who enjoy viewing wild burro herds in the area would be further reduced from the cumulative impacts of herd reduction activities on Bureau of Land Management and National Forest System lands. These impacts are expected to be minor.
Alternative 3 Alternative 3 was developed in response to concerns about the costs associated with the proposed action. Alternative 3 would reduce the burro population and reduce cost by not placing wild burros in long-term holding facilities. Instead, short-term holding for adoption and sterilization, as described in the environmental assessment, would be conducted. Direct and indirect effects of
Humboldt-Toiyabe National Forest 154 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
alternative 3 are described below and summarized in table 40. The temporal boundaries for analyzing the direct and indirect effects is 25 years, from 2018 through 2043. Project activities described in each alternative are expected to continue, and to impact the study area past 2043, however, it is difficult to predict the scale of impacts and project needs beyond 25 years.
Direct and Indirect Effects
Economic Impact – Project activities Overall, alternative 3 is anticipated to provide minor economic benefits. Project activities would support a total of 26.7 jobs and $713,300 in labor income over 25 years, approximately 1 job and $28,500 in labor income annually. These jobs would occur sporadically over a 25-year period as bait, trap, adoption, short-term holding, and fertility vaccination activities occur. Estimates provided here assume that bait, trap, short-term holding, and adoption activities would occur in the first 3 years of the project; fertility vaccinations would occur in the first year of the project and will continue every other year for 25 years.
Jobs and income presented here are occurring primarily in the industry for support activities for agricultural. Indirectly, project spending supports employment in transportation, assorted retail and hospitality sectors, trade, and engineering. Note that employment and income estimates provided above are not new jobs created in the local economy. Project activities would support employment and income in the sectors listed above.
Contracting costs used to determine job and income estimates are the maximum anticipated. This means job and income values are the upper bound. Actual costs may be lower, in which case job and income estimates would also be lower. Actual management needs may vary based on the conditions and herd size, which may change spending and thus, job and income estimates.
Economic Impact - Grazing Economic impact from grazing would be similar to the proposed action, however the benefits of from reduced grazing pressure and improved vegetation would occur on a longer time horizon.
Financial Efficiency The total cost of project activities under alternative 3 is $1,180,253 for the 25 year period this report analyzes. The present net value for project activities (discounted 4 percent over 25 years) is $(905,641). There are no monetary benefits associated with the project; therefore, the present net value is a large negative value. While the benefits are not monetarily quantifiable, they would still exists. For example, a smaller burro population may lead to improved range conditions which would support jobs and income for local ranchers.
The total cost of project activities under alternative 3 would be approximately $391,247 (25 percent) less than the proposed action (alternative 2) over the same period. However, alternative 3 cost estimates assume that PZP 22 fertility vaccine is used and administered every other year. Other fertility vaccines are available but need to be administered annually, which would increase the costs of alternative 3 by nearly $600,000 over 25 years.
Environmental Justice Impacts to members of an environmental justice community would be similar to those described in the proposed action. Potential economic benefits to members of these communities, while still positive, are lower than the proposed action. Under alternative 3, there is less project spending, therefore, fewer jobs and less labor income would be supported.
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Recreation – Quality of Life and Economic Impact Same as the proposed action.
Table 40. Resource indicators and measures for alternative 3 direct and indirect effects Resource Indicator Resource (quantify if Measure Alternative 3 Element possible) (quantify if possible) Direct and Indirect Effects Economic impact – Economic activity Employment and labor Minor economic benefits. project activities income Annually, 1 job and $28,500 in labor income would be supported from project spending, for a total of 26.7 jobs and $713,300 in labor income over 25 years. Economic impact – Economic activity Employment and labor Same as the proposed grazing income action (alternative 2), but benefits would occur over a longer timeline. Financial efficiency Discounted values of Present Net Value Present net value costs and benefits $(905,641). Benefits associated with the project are not monetary; therefore, present net value is a large negative number. Environmental Disproportionate and Identification of low income No negative impacts to justice adverse effects to and minority populations in members of an low-income the study area environmental justice populations, minority community are anticipated. populations, or both Project spending has the potential to would provide a positive economic benefits to the environmental justice community if jobs and income are absorbed by members of these communities, benefits would be less than those described in the proposed action because project spending is lower. Quality of life Recreation use Qualitative discussion, Same as the proposed values – wildlife national visitor use action. viewing monitoring – wildlife viewing and visitation data
Cumulative Effects Cumulative effects are the same as those described under alternative 2.
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Degree to Which the Alternatives Address the Issues Table 41 summarizes the economic impact to grazing across alternatives.
Table 41. Summary comparison of how the alternatives address the key issues Purpose and Indicator or Need Measure Alternative 1 Alternative 2 Alternative 3 Economic impact Economic activity Negative impact. A If improved Same as the – grazing – jobs and income larger burro herd range conditions proposed action would continue to from herd (alternative 2), negatively impact reduction but benefits grazing and forage continues to would occur over conditions, limiting support a longer timeline. the available maximum animal resources for unit months, then permittees. As a 2 jobs and result, permittees $67,000 in labor may reduce herd size income would be or have to substitute supported for private forage, annually. increasing costs and reducing management efficiency. Potential loss of 2 jobs and $67,000 in labor income.
Summary of Environmental Effects Table 42 provides a summary of environmental impacts to socioeconomic resources by alternative. Overall, the impacts to socioeconomic resources are anticipated to be minor. Positive impacts include project spending that would support employment and labor income, as well as improved grazing conditions. Negative impacts may occur to recreation visitors who enjoy viewing the herd as well as recreation related economic benefits supported by wildlife viewing, however, these impacts are expected to be minimal.
Project spending would support employment and labor income; however, these jobs are not new jobs in the local economy. They are jobs already occurring in the local area that would be supported through project spending. On an annual basis, project spending would support 1.4 jobs and $38,000 in labor income, and alternative 3 would support 1 job and $28,500 in labor income over the 25-year time frame this report analyzes.
Grazing permittees in the project area would likely experience positive outcomes from both the proposed action and alternative 3. Reducing the wild burro herd size within the appropriate management level range would help maintain rangeland forage in satisfactory conditions for continued grazing, these benefits would occur over a longer time horizon under alternative 3.
Reducing the herd size within the appropriate management level range may make it more difficult to find and view the wild burros; however, visitation for this purpose is minimal and it is unlikely a smaller herd size would have measurable impacts to either visitation or the economy. If the herd size does become more difficult to view, it may reduce quality of life for those visitors who do enjoy visiting the herd.
Humboldt-Toiyabe National Forest 157 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Negative impacts to members of an environmental justice community are not anticipated under either the proposed action or alternative 3. If employment and labor income resulting from project spending are absorbed by low-income and minority populations, project activities may benefit members of these communities. Additionally, a smaller herd size may improve local grazing conditions and limit the impact to grazing conditions outside the Hickison Wild Burro Territory. If members of an environmental justice community are currently impacted or would be impacted by degraded forage conditions from burros, then the proposed action and alternative 3 would benefit these communities. Benefits that may be experienced under alternative 3 would occur over a longer time horizon compared to the proposed action.
Table 42. Summary comparison of environmental effects to socioeconomic resources Resource Indicator or Element Measure Alternative 1 Alternative 2 Alternative 3 Economic impact Economic activity No impact Minor economic Minor economic – project activities benefits. Annually, benefits. Annually, 1.4 jobs and 1 job and $28,500 $38,000 in labor in labor income income would be would be supported from supported from project spending, project spending, for a total of 35.5 for a total of 26.7 jobs and $949,700 jobs and $713,300 in labor income in labor income over 25 years. over 25 years. Economic impact Economic activity Minor negative Minor positive Same as the – grazing Impact. It is likely a impacts, if proposed action larger burro herd improved range (alternative 2), but will continue to conditions from benefits would negatively impact herd reduction occur over a grazing and forage continues to longer timeline. conditions, limiting support maximum the available animal unit resources for months, then 2 permittees. jobs and $67,000 in labor income would be supported annually. Financial Discounted values No impact Present net value Present net value efficiency of costs and $(1,173,446). $(905,641). benefits Benefits Benefits associated with the associated with the project are not project are not monetary; monetary; therefore, present therefore, present net value is a large net value is a large negative number. negative number.
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Resource Indicator or Element Measure Alternative 1 Alternative 2 Alternative 3 Environmental Disproportionate Possible negative No negative No negative justice and adverse economic impacts impacts to impacts to effects to low- to members of an members of an members of an income environmental environmental environmental populations, justice community justice community justice community minority if grazing are anticipated. are anticipated. populations, or permittees are Project spending Project spending both members of an has the potential to has the potential to environmental provide economic provide economic justice community, benefits to the benefits to the or if the growing environmental environmental herd roams further justice community justice community into areas grazed if jobs and income if jobs and income by members of an are absorbed by are absorbed by environmental members of these members of these justice community. communities. communities, benefits would be less than those described in the proposed action because project spending is lower. Quality of life and Recreation use The no-action Marginal negative Marginal negative economic impact values – wildlife alternative may impact. Reducing impact. Reducing viewing; economic improve quality of herd size within herd size within impact of wildlife life for visitors if the appropriate the appropriate viewing the burro management level management level population range would make range would make becomes easier to it more difficult to it more difficult to view as a result of find and view the find and view the unmanaged herd – reducing herd – reducing population growth. quality of life for quality of life for However, it is likely visitors; visitation visitors; visitation the burros would for this purpose is for this purpose is remain difficult to limited and it is limited and it is locate and view unlikely that a unlikely that a and visitation for reduced herd size reduced herd size this purpose is would have a would have a expected to remain measurable impact measurable impact minimal. If to visitation or to to visitation or to visitation to this the economy. the economy. area increased, economic impact from recreation visitation to view burros on the Humboldt-Toiyabe is unlikely to measurably grow.
Humboldt-Toiyabe National Forest 159 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project Environmental Assessment
Agencies and Persons Consulted Public involvement, notification and mailing, and public input for this project are described earlier in this document (see Public Involvement and Proposal Development). A complete list of persons and other organizations contacted is available in the project record. Tribes, agencies, and governments contacted or consulted for this project include:
• Duckwater Shoshone Tribe • Yomba Shoshone Tribe • Nevada State Historic Preservation Office (SHPO) • U.S. Fish and Wildlife Service • Bureau of Land Management • Nevada Department of Wildlife • Lander County • Eureka County • Nye County • Mark Amodei, U.S. Representative • Harry Reid, U.S. Senator • Dean Heller, U.S. Senator
Humboldt-Toiyabe National Forest 160 Hickison Wild Burro Territory Appropriate Management Levels and Management Actions Project
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