2020-09255. Hart Mountain National Antelope Refuge, Lake County, OR; Notice of Intent To Prepare a Bighorn Sheep Management Plan and Environmental Impact Statement

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Notice of intent; request for comments.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), intend to prepare a management plan (plan) for bighorn sheep (Ovis canadensis) for Hart Mountain National Antelope Refuge (refuge). We will also prepare an environmental impact statement to develop alternatives for management actions in the plan and evaluate the environmental effects of those actions. We provide this notice in compliance with the National Environmental Policy Act to advise the public, other Federal and State agencies, and Tribes of our intentions, and to obtain public comments and suggestions on the scope of the issues to consider in the planning process.

DATES:

To ensure consideration, written comments must be received or postmarked on or before June 8, 2020.

ADDRESSES:

Information concerning the refuge and the bighorn sheep population is available on our website, at https://www.fws.gov/​refuge/​Hart_​Mountain/​What_​We_​Do/​Resource_​Management/​Bighorn_​Sheep_​Plan.html.

Send your questions or comments by any of the following methods:

• Email: [e-mail]. Include “Hart Mountain Bighorn Sheep Plan” in the subject line of the message.
• U.S. Mail: Project Leader, Sheldon-Hart Mountain National Wildlife Refuge Complex, P.O. Box 111, Lakeview, OR 97630.

FOR FURTHER INFORMATION CONTACT:

Danielle Fujii-Doe, Refuge Manager, by email at [e-mail] or by phone at 541-947-2731. Individuals who are hearing or speech impaired may call the Federal Relay Service at 1-800-877-8339 for TTY assistance.

SUPPLEMENTARY INFORMATION:

Introduction

We, the U.S. Fish and Wildlife Service (Service), intend to prepare a management plan (plan) for bighorn sheep (Ovis canadensis) for Hart Mountain National Antelope Refuge (refuge). We will also prepare an environmental impact statement to develop alternatives for management actions in the plan and evaluate the environmental effects of those actions. We provide this notice in compliance with the National Environmental Policy Act (NEPA; 42 U.S.C. 1531 et seq.) to advise the public, other Federal and State agencies, and Tribes of our intentions, and to obtain public comments and suggestions on the scope of the issues to consider in the planning process.

Background

Located in a remote area of south central Oregon, Hart Mountain National Antelope Refuge, managed by the Service, encompasses 278,000 acres of sagebrush-steppe habitat within the Great Basin and includes the 19,267-acre proposed Poker Jim Wilderness Area. Originally established in 1936 for the conservation and protection of the once-imperiled pronghorn (Antilocapra americana), the refuge also conserves habitat for many native, rare, and imperiled species of fish, wildlife, and plants that depend upon the sagebrush-steppe ecosystem.

Bighorn sheep are an iconic species native to Oregon and the refuge. Originally extirpated in Oregon by 1912, sheep were successfully reintroduced to the State in 1954, when 20 sheep were translocated to Hart Mountain. Since that time, refuge and Oregon Department of Fish and Wildlife (ODFW) staff have conducted annual surveys to track population variables, including number of sheep, lamb production and recruitment, and ram size/age class. The number of sheep counted on the refuge increased yearly from 1954, reaching a high of 350 to 415 sheep during the period 1982-1992. However, beginning in the 1990s, the number steadily declined to approximately 150 animals, and then remained relatively stable during the period 2009-2017. The last three annual surveys represent the most significant declines in population variables to date. The number of sheep counted dropped from 149 in 2017, to 100 in 2018, to 68 in 2019. Lamb production declined by approximately half from 54.4 lambs per 100 ewes in 2017, to 21.5 and 22.7 in 2018 and 2019, respectively. In addition, recruitment reached a low level in 2019, with no 1-year-old class I rams and only two oldest age class IV rams seen.

Sheep habitat encompasses approximately 34,000 acres on the western escarpment of the refuge (Hart Mountain and Poker Jim Ridge), including the proposed Poker Jim Wilderness Area. However, ecological trends over the last several decades, such as juniper encroachment and the spread of invasive herbaceous plants, may be resulting in the decline in the quality of sheep habitat.

In January 2019, ODFW, in cooperation with refuge staff, captured 21 sheep on the refuge. Nineteen were fitted with GPS collars to monitor movements and track adult survival. In addition, health-screening samples were obtained on all 21 sheep. The ODFW Wildlife Heath and Population Laboratory analyzed the health screening samples and submitted tonsillar swabs and blood serum for diagnostic tests to both Oregon State University and Washington Animal Disease Diagnostics Laboratory in Pullman, Washington, to be screened for a number of pathogens, including Mycoplasma ovipneumoniae (M. ovi), a bacterium known to be associated with acute pneumonia mortality events. However, M. ovi was not detected in any of the samples, and there does not appear to be a clear association of the population decline with respiratory disease or other common diseases. Since January 2019, eight of 19 radio-collared sheep have died; six because of mountain lion predation, one killed legally by a hunter, and one from unknown causes.

Given rapidly declining sheep numbers and 2 years of poor lamb recruitment, the herd is at risk of extirpation from the refuge in the next few years unless appropriate management actions are taken. In response, ODFW suspended sheep hunting on the Refuge following the 2019 hunting season. Because there is considerable uncertainty about what the proximate and ultimate causes of this decline are, development of a management plan and EIS are warranted in order to analyze existing data and identify short- and long-term alternatives and actions needed to restore the bighorn sheep herd to a self-sustaining population level. Possible management actions include continued monitoring, management of the sheep and associated predator populations, and restoration and maintenance of habitat.

Preliminary Issues, Concerns, and Opportunities

Based on the fundamental principles of wildlife management, we have identified the following preliminary issues, concerns, and opportunities regarding the sheep population that we may address in the plan. Additional issues may be identified during the public scoping process.

• Bighorn sheep population objectives. What parameters should the Service use to define a self-sustainable population on the refuge? What criteria or triggers should the Service consider when deciding to implement or suspend management actions?
• Bighorn sheep survival and mortality. What actions can the Service take to improve sheep survival and lamb recruitment? What are the effects of the various sources of mortality—including disease, predation, and hunting—on the long-term viability of the sheep population? Given risks of disease introductions, is there a role for augmenting the sheep population?
• Habitat quality and quantity. What actions can the Service take to maintain and restore sheep habitat? How are western juniper expansion and invasive plant species (invasive annual grasses including cheatgrass) affecting the sheep population? Is there a role for prescribed fire to manage sheep habitats? Is natural water availability a limiting resource?
• Potential alternatives and environmental analysis. Potential alternatives include a focus on habitat, a focus on population management, or a combination of approaches. What alternatives for restoring the bighorn sheep population should the Service explore? Which components of the human environment should the Service emphasize in the environmental analysis?

Public Availability of Comments

All comments received from individuals become part of the official public record. We will handle all requests for such comments in accordance with the Freedom of Information Act and the CEQ's NEPA regulations at 40 CFR 1506.6(f). The Service's practice is to make comments, including names and home addresses of respondents, available for public review during regular business hours. Individual respondents may request that we withhold their home address from the record, which we will honor to the extent allowable by law. If you wish us to withhold your name and/or address, you must state this prominently at the beginning of your comments.

Charles Stenvall,

Acting Regional Refuge Chief, Pacific Region, Portland, Oregon.