Endangered and Threatened Wildlife and Plants; Withdrawal of the Proposed Rules To List the Bi-State Distinct Population Segment of Greater Sage-Grouse With Section 4(d) Rule and To Designate Critical Habitat

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket Nos. FWS-R8-ES-2018-0106 and FWS-R8-ES-2018-0107; FF09E21000 FXES11110900000 201]

RINs 1018-BD87 and 1018-BD88

Endangered and Threatened Wildlife and Plants; Withdrawal of the Proposed Rules To List the Bi-State Distinct Population Segment of Greater Sage-Grouse With Section 4(d) Rule and To Designate Critical Habitat

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Proposed rule; withdrawal.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), withdraw the proposed rule to list the Bi-State distinct population segment (DPS) of greater sage-grouse (

Centrocercus urophasianus

) in California and Nevada as threatened under the Endangered Species Act of 1973, as amended (Act). We concurrently withdraw the proposed rule under section 4(d) of the Act and the proposed rule to designate critical habitat for the DPS. These withdrawals are based on our conclusion that the threats to the DPS as identified in the proposed listing rule no longer are as significant as believed at the time of publication of the 2013 proposed rule. We find the best scientific and commercial data available indicate that the threats to the DPS and its habitat, given current and future conservation efforts, are reduced to the point that the DPS does not meet the Act's definition of an “endangered species” or of a “threatened species.”

DATES:

The U.S. Fish and Wildlife Service is withdrawing proposed rules published on October 28, 2013 (78 FR 64328 and 64358) as of March 31, 2020.

ADDRESSES:

Relevant documents are available on the internet at either Docket No. FWS-R8-ES-2018-0106 or Docket No. FWS-R8-ES-2018-0107 on

http://www.regulations.gov.

Relevant documents used in the preparation of this withdrawal are also available for public inspection, by appointment, during normal business hours at the Reno Fish and Wildlife Office (see

FOR FURTHER INFORMATION CONTACT

).

FOR FURTHER INFORMATION CONTACT:

Lee Ann Carranza, Deputy Field Supervisor, Reno Fish and Wildlife Office, 1340 Financial Boulevard, Suite 234, Reno, NV 89502; telephone 775-861-6300. Persons who use a telecommunications device for the deaf (TDD) may call the Federal Relay Service at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

Why we need to publish this document.

Under the Act, a species may warrant protection through listing if it is endangered or threatened throughout all or a significant portion of its range. We issued a proposed rule to list a distinct population segment (DPS) of greater sage-grouse in California and Nevada (known as the Bi-State DPS) in 2013. However, this document withdraws that proposed rule because we now determine that threats identified in the proposed rule have been reduced such that listing is not necessary for this DPS. Accordingly, we also withdraw the proposed rule under section 4(d) of the Act and the proposed critical habitat designation.

The basis for our action.

Under the Act, we may determine that a species is an endangered or threatened species because of any of five factors: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence. We have determined that threats have been reduced such that listing is not necessary for the Bi-State DPS of greater sage-grouse.

Peer review.

In accordance with our joint policy on peer review published in the

Federal Register

on July 1, 1994 (59 FR 34270), and our August 22, 2016, memorandum updating and clarifying the role of peer review of listing actions under the Act, we sought the expert opinions of five appropriate specialists regarding the species report. We received responses from three specialists, which informed this finding. The purpose of peer review is to ensure that our listing determinations, critical habitat designations, and 4(d) rules are based on scientifically sound data, assumptions, and analyses. The peer reviewers have expertise in the biology, habitat, and threats to the greater sage-grouse.

Acronyms and Abbreviations Used in This Document

We use many acronyms and abbreviations throughout this document. To assist the reader, we provide a list of these here for easy reference:

ac = acres

Act or ESA = Endangered Species Act of 1973, as amended (16 U.S.C. 1531

et seq.

)

BLM = Bureau of Land Management

BSAP = Bi-State Action Plan

BSLPG = Bi-State Local Planning Group

BSLSP = Bi-State Lek Surveillance Program

CDFW = California Department of Fish and Wildlife (formerly California Department of Fish and Game (CDFG))

CFR = Code of Federal Regulations

COT = Conservation Objectives Team

CPT = conservation planning tool

CRI = credible intervals

DPS = distinct population segment

EOC = Executive Oversight Committee

FR = Federal Register

ha = hectares

HTNF = Humboldt-Toiyabe National Forest

IPM = integrated population model

LADWP = Los Angeles Department of Water and Power

LRMP = land resource management plan

NDOW = Nevada Department of Wildlife

NEPA = National Environmental Policy Act (42 U.S.C. 4321

et seq.

)

NFMA = National Forest Management Act (16 U.S.C. 1600

et seq.

)

NRCS = Natural Resources Conservation Service

OHV = off-highway vehicle

PECE = Policy for Evaluation of Conservation Efforts When Making Listing Decisions

PEIS = Programmatic Environmental Impact Statement

PMU = population management unit

RHA = rangeland health assessment

RMP = resource management plan

Service = U.S. Fish and Wildlife Service

TAC = Technical Advisory Committee

USDA = U.S. Department of Agriculture

USFS = U.S. Forest Service

USGS = U.S. Geological Survey

WAFWA = Western Association of Fish and Wildlife Agencies

WNv = West Nile virus

Previous Federal Actions

The Bi-State DPS of the greater sage-grouse has a long and complex rulemaking history. Here, we will discuss only the major Federal actions related to the species. For a detailed description of previous Federal actions, please refer to the previous withdrawal of the proposed listing rule, published on April 23, 2015 (80 FR 22828), and the Policy for Evaluation of Conservation Efforts When Making Listing Decisions (PECE) analysis we prepared as a supporting document for this determination (Service 2019, pp. 1-6).

On October 28, 2013, we published a proposed rule to list the Bi-State DPS as a threatened species with a 4(d) rule (78 FR 64358). On that same day, we published a proposed rule to designate critical habitat for the Bi-State DPS (78 FR 64328).

On April 23, 2015, we withdrew the proposed listing rule, the proposed 4(d) rule, and the proposed critical habitat rule (80 FR 22828). This withdrawal

was based on our conclusion that the threats to the DPS as identified in the proposed listing rule were no longer as significant as believed at the time of publication of the proposed rule. We found that the best scientific and commercial data available indicated that the threats to the DPS and its habitat, given current and future conservation efforts as analyzed under PECE, were reduced to the point that the DPS did not meet the Act's definition of an “endangered species” or of a “threatened species.”

On March 9, 2016, Desert Survivors, the Center for Biological Diversity, WildEarth Guardians, and Western Watershed Project filed suit in the U.S. District Court for the Northern District of California. The suit challenged the withdrawal of the proposal to list the Bi-State DPS. On May 5, 2018, the court issued a decision. The April 23, 2015, withdrawal was vacated and remanded to the Service for further consideration. The court's action reinstated the prior proposed rules to list and to designate critical habitat for the Bi-State DPS, thereby returning the process to the proposed rule stage, and the status of the Bi-State DPS effectively reverted to that of a species proposed for listing for the purposes of consultation under section 7 of the Act. The court's action also reinstated the proposed 4(d) rule and the proposed critical habitat designation for the Bi-State DPS.

On April 12, 2019, we published in the

Federal Register

(84 FR 14909) a document that announced that the proposed rules were reinstated and the public comment periods were reopened for 60 days and that we would publish a final listing determination on or before October 1, 2019.

On October 1, 2019, we announced a 6-month extension of the final listing determination to April 1, 2020 (84 FR 52058). We took that action based on substantial disagreement regarding the sufficiency and accuracy of the available data relevant to the proposed listing, which made it necessary to solicit additional information. That document reopened the public comment period on the proposed listing and critical habitat rules for an additional 30 days.

Supporting Documents

We prepared a species report for the Bi-State DPS (Service 2020, entire). The species report represents a compilation of the best scientific and commercial data available concerning the status of the species, including the impacts of past, present, and future factors (both negative and beneficial) affecting the species. The Service sent the species report to five independent peer reviewers and received three responses. The Service also sent the species report to all pertinent Federal, Tribal, and State partners, including scientists with expertise in sage-grouse and sage-brush habitat in the Bi-State area. We received reviews from six partners (Humboldt-Toiyabe National Forest (HTNB), Inyo National Forest, two Bureau of Land Management (BLM) offices: Bishop and Carson City, the California Department of Fish and Wildlife (CDFW), and the Nevada Department of Wildlife (NDOW)). These comments have been incorporated into the species report and informed this document.

Summary of Changes From the Proposed Rule

Based upon our review of the public comments, Federal and State agency comments, peer review comments, issues addressed at the public hearings, and any new relevant information that became available since the publication of the proposal and including new relevant information that has become available since the prior withdrawal decision, we reevaluated our proposed listing rule and made changes as appropriate in this withdrawal. Other than minor clarifications and incorporation of additional information on the species' biology and populations, this determination differs from the proposal in the following ways:

(1)

A different status determination.

Based on our analyses of the potential threats to the species, and our consideration of partially completed, ongoing and future conservation efforts (as outlined below in Policy for Evaluation of Conservation Efforts When Making Listing Decisions), we have determined that the Bi-State DPS should not be listed as a threatened species. Specifically, we have determined that conservation efforts (as outlined in the Bi-State Action Plan (BSAP), Agency commitment letters, and our detailed PECE analysis (all of which are available at either Docket No. FWS-R8-ES-2018-0106 or Docket No. FWS-R8-ES-2018-0107 on

http://www.regulations.gov

as well as the Technical Advisory Committee (TAC) comprehensive project database)) will continue to be implemented because (to date) we have a documented track record of active participation and implementation by the signatory agencies and commitments to continue implementation into the future.

Conservation measures, such as (but not limited to) pinyon-juniper removal, establishment of conservation easements for critical brood-rearing habitat, cheatgrass (

Bromus tectorum)

removal, permanent and seasonal closure of roads near leks, removal and marking of fencing, and restoration of riparian/meadow habitat have been occurring over the past decade, are currently occurring, and have been prioritized and placed on the agencies' implementation schedules for future implementation. Agencies have committed to remain participants in the BSAP and to continue conservation of the DPS and its habitat. Additionally, the BSAP has sufficient methods for determining the type and location of the most beneficial conservation actions to be implemented, including continued development of new population and threats information in the future that will guide conservation efforts. As a result of these actions, this document withdraws the proposed rules as published on October 28, 2013 (78 FR 64328; 78 FR 64358).

We have also updated our Significant Portion of the Range analysis based on a recent court finding regarding the policy.

(2)

Addition of PECE analysis.

This document includes the Policy for Evaluation of Conservation Efforts When Making Listing Decisions section, which includes some information presented in the Available Conservation Measures section of the proposed listing rule.

(3)

Population impacts.

This document includes a discussion of the impacts of small population size and population isolation on the Bi-State DPS.

(4)

New information.

Following publication of the proposed listing rule, we received new information pertinent to this rulemaking action. Some of the information was in response to our request for scientific peer review of the proposed listing rule, while other information was a result of new literature now available, or updated regulations. We incorporated all new information into the Species Report (Service 2020, entire), which is available on the internet at

http://www.regulations.gov

under either Docket No. FWS-R8-ES-2018-0106 or Docket No. FWS-R8-ES-2018-0107, as well as within this document where appropriate. New information includes (but is not limited to):

• A variety of biological or habitat clarifications, such as hen movement distances, nesting success, and invasive plant species influence on sagebrush-habitat dynamics.

• Updated trend and population analyses. Multiple new papers examining the population dynamics and trends of the Bi-State DPS (Coates et al. 2014, entire; Coates et al. 2018, entire; Mathews et al. 2018, entire; Coates et al.

2020, entire). These studies are incorporated into the Species Report and discussed throughout this document.

• Two genetic evaluations, one of which concluded there are three or four unique genetic clusters within the Bi-State area (Oyler-McCance et al. 2014, p. 8), and a second that concluded there were five unique genetic clusters (Tebbenkamp 2014, p. 18). Tebbenkamp (2014) did not evaluate the Pine Nut population; thus, six populations may have been identified by Tebbenkamp (2014) had the Pine Nut population data been available.

• New information on the effectiveness of pinyon-juniper removal has become available in recent years (Prochazka et al. 2017, entire; Severson et al. 2017, entire; Sandford et al. 2017, entire; Coates et al. 2017b, entire; Olsen 2019, entire). These studies are incorporated into the Species Report and discussed throughout this document.

(5)

New ESA factor D analysis.

In the 2013 proposed listing rule, we analyzed the adequacy of existing regulatory mechanisms in a separate section. Here, we evaluate the effects of existing regulatory mechanisms within each threat analysis, rather than evaluating regulatory mechanisms in a separate section, so that it is clear how the existing regulatory mechanisms relate to the stressor being analyzed.

(6)

Significant portion of the range (SPR) analysis.

Since 2013, we have a new policy regarding the Service's interpretation of the phrase “significant portion of the range” (79 FR 37578; July 1, 2014). We also have new guidance regarding application of that policy (Service 2017, entire), which was published subsequent to the 2015 withdrawal of the proposed rule. Additionally, certain parts of the policy have been invalidated by court orders. We have completed our SPR analysis for the Bi-State DPS in accordance with the 2014 policy and the 2017 guidance as further refined by applicable court decisions.

Background

In our 12-month findings on petitions to list three entities of sage-grouse (75 FR 13910, March 23, 2010), we found that the Bi-State population of greater sage-grouse in California and Nevada meets our criteria to qualify as a DPS of the greater sage-grouse under Service policy (61 FR 4722, February 7, 1996). We reaffirmed this finding in the October 28, 2013, proposed listing rule (78 FR 64358) and do so again in this document. This determination is based principally on genetic information (Benedict et al. 2003, p. 308; Oyler-McCance et al. 2005, p. 1307), where the DPS was found to be both markedly separated and significant to the remainder of the greater sage-grouse taxon. The Bi-State DPS defines the far southwestern limit of the species' range along the border of eastern California and western Nevada (Stiver et al. 2006, pp. 1-11; 71 FR 76058, December 19, 2006).

Although the Bi-State DPS is a genetically unique and markedly separate population, the DPS has similar life-history and habitat requirements to the greater sage-grouse throughout the rest of its range. In the October 28, 2013, proposed listing rule (78 FR 64358), the species report, and this document, we use information specific to the Bi-State DPS where available but still apply scientific management principles for greater sage-grouse that are relevant to the Bi-State DPS's management needs and strategies. This practice is followed by the wildlife and land management agencies that have responsibility for management of both the DPS and its habitat.

A detailed discussion of the Bi-State DPS's description, taxonomy, habitat (sagebrush ecosystem), seasonal habitat selection, life-history characteristics, home range, life expectancy and survival rates, historical and current range distribution, population estimates and lek (sage-grouse breeding complex) counts, population trends, and land ownership information is available in the species report (Service 2020, entire). The species report represents a compilation of the best scientific and commercial data available concerning the status of the Bi-State DPS, including the past, present, and future threats to this DPS. The species report and other materials relating to this final agency action can be found at

http://www.regulations.gov

under either Docket No. FWS-R8-ES-2018-0106 or Docket No. FWS-R8-ES-2018-0107.

Habitat and Life History

Sage-grouse depend on a variety of shrub and shrub-steppe vegetation communities throughout their life cycle (Schroeder et al. 2004, p. 364). Sagebrush is the most widespread vegetation in the intermountain lowlands of the western United States and is considered one of the most imperiled ecosystems in North America (West and Young 2000, p. 259; Knick et al. 2003, p. 612; Miller et al. 2011, p. 147). Most species of sagebrush are killed by fire; historical fire-return intervals are estimated to be as long as 350 years (West 1983, p. 341; Miller and Eddleman 2000, p. 17; West and Young 2000, p. 259; Baker 2011, pp. 191-192). Natural sagebrush recolonization in burned areas depends on the presence of adjacent live plants for a seed source or on the seed bank, if present, and requires from decades to over a century for full recovery (Miller and Eddleman 2000, p. 17; Baker 2011, pp. 194-195).

Sage-grouse require large, interconnected expanses of sagebrush with healthy, native understories, in part to accommodate their seasonal shifts in habitat selection within the sagebrush ecosystem (Service 2020, p. 11). Sage-grouse exhibit strong site fidelity (loyalty to a particular area) to migration corridors and seasonal habitats, including breeding, nesting, brood-rearing, and wintering areas; they exhibit this fidelity even when a particular area may no longer be of value, limiting the species' adaptability to habitat changes (Service 2020, p. 11). However, recent research has suggested that this high degree of site fidelity may be more flexible than has traditionally been considered, at least with respect to certain restoration actions (

e.g.,

tree removal; Sandford et al. 2017, p. 64; Severson et al. 2017, p. 55).

During the spring breeding season, male sage-grouse gather to perform courtship displays at leks or traditional strutting grounds. Areas of bare soil, short-grass steppe, windswept ridges, exposed knolls, or other relatively open sites typically serve as leks (Patterson 1952, p. 83; Connelly et al. 2004, p. 3-7 and references therein). The proximity, configuration, and abundance of nesting habitat are key factors influencing lek location (Connelly et al. 1981, pp. 153-154; Connelly et al. 2000a, p. 970). Leks can be formed opportunistically at any appropriate site within or adjacent to nesting habitat (Connelly et al. 2000a, p. 970); therefore, lek habitat availability is not considered a limiting factor for sage-grouse (Schroeder et al. 1999, p. 4). Leks range in size from less than 0.04 ha (0.1 ac) to over 36 ha (90 ac) (Connelly et al. 2004, p. 4-3) and can host from a few to hundreds of males (Johnsgard 2002, p. 112).

The distances sage-grouse move between seasonal habitats are highly variable across the occupied range (Connelly et al. 1988, pp. 119-121). Migration can occur between distinct winter, breeding, and summer areas or the seasonal-use areas may be variously integrated (

e.g.,

winter and breeding areas may be the same and brood-rearing sites are disjunct). Information available regarding seasonal migrations and migratory corridors for sage-grouse in the Bi-State area is variable. Some local breeding complexes (a general

aggregation of birds associated with a particular lek or collection of leks in relatively close proximity to one another) remain fairly resident throughout the year while others demonstrate a more itinerant nature (Casazza et al. 2009, p. 8).

Still, all sage-grouse gradually move from sagebrush uplands to more mesic areas (moist areas such as upland meadows) during the late brood-rearing/summer period (3 weeks post-hatch) in response to summer desiccation of herbaceous vegetation (Connelly et al. 2000a, p. 971; Atamian et al. 2010, p. 1538; Connelly et al. 2011b, pp. 76-77 and references therein; Pratt et al. 2017, p. 635). Brood-rearing foraging habitats with increased perennial forb cover and plant species richness, greater meadow to sagebrush edge (ratio of perimeter to area), and a greater distance from woodlands provide for an increased probability of successful recruitment (Casazza et al. 2011, pp. 162-163). Sage-grouse will use free water, although they do not require it since they obtain water from their food. However, natural water bodies and reservoirs provide mesic areas often rich in succulent forb and insect food sources, thereby attracting sage-grouse hens with broods (Connelly et al. 2004, p. 4-12).

Non-migratory sage-grouse populations have been described as those with seasonal movements of less than 10 km (6.2 mi; Connelly et al. 2000a, pp. 968-969), while birds in migratory populations may travel well over 100 km (62 mi) (Tack et al. 2012, p. 65). Despite the documentation of extensive seasonal movements in this species, dispersal (permanent rather than seasonal movement) abilities of sage-grouse to other areas are assumed to be low (Fedy et al. 2012, p. 1066; Tack et al. 2012, p. 65; Davis et al. 2014, p. 716). Sage-grouse dispersal is overall poorly understood and appears sporadic, if not rare (Service 2020, p. 12).

Range and Population Estimates

The Bi-State DPS of greater sage-grouse historically occurred throughout most of Mono, eastern Alpine, and northern Inyo Counties, California (Hall et al. 2008, p. 97), and portions of Carson City, Douglas, Esmeralda, Lyon, Mineral, and perhaps Storey County in Nevada (Gullion and Christensen 1957, pp. 131-132; Espinosa 2019, pers. comm.). The current range of the DPS in California is presumed to be reduced from the historical range (Leach and Hensley 1954, p. 386; Hall 1995, p. 54; Schroeder et al. 2004, pp. 368-369), but the extent of range loss is not well understood.

Current management of the Bi-State DPS employs Population Management Units (PMUs) for Nevada and California as tools for defining and monitoring sage-grouse distribution. The PMU boundaries represent generalized populations or local breeding complexes and were delineated based on aggregations of leks, known seasonal habitats, and telemetry data. Six PMUs were designated for the Bi-State DPS (from north to south): Pine Nut, Desert Creek-Fales, Bodie, Mount Grant, South Mono, and White Mountains (Figure 1; Table 1). These six PMUs represent a combined total of approximately 50 active leks (see Table 1 below; Service 2020, pp. 21-33). Leks are considered either active (

e.g.,

two or more strutting males during at least 2 years in a 5-year period), inactive (

e.g.,

surveyed three or more times during one breeding season with no birds detected and no sign (

e.g.,

droppings) observed), historical (

e.g.,

no strutting activity for 20 years and have been checked according to State protocol at least intermittently), or unknown/pending (

e.g.,

sign was observed, and one or no strutting males observed, or a lek that had activity the prior year but was not surveyed or surveyed under unsuitable conditions during the current year and reported one or no strutting males).

BILLING CODE 4333-15-P

EP31MR20.012

BILLING CODE 4333-15-C

Table 1—Bi-State DPS PMUs, PMU Size, Estimated Suitable Sage-Grouse Habitat, Average Number of Leks, Average Number of Active Leks, and Range of Maximum Males on Leks Within Each PMU (2003-2018)

[Number pairs in parentheses are lower and upper limits of the 95 percent credible interval. Area values for “Total Size” and “Estimated Suitable Habitat” may not sum due to rounding]

PMU

Total size in

hectares

(acres)

(*)

Estimated suitable habitat in

hectares

(acres)

(**)

Average number of

leks

(***)

Average number of

active leks

(***†)

Range in maximum male counts

(****)

Pine Nut

232,440

(574,372)

77,848 (192,367)

7.3 (2.0, 9.0)

1.8 (0.3, 4.7)

0-67

Desert Creek-Fales ††

229,858

(567,992)

105,281

(260,155)

12.8 (8.3, 15.0)

6.8 (5.0, 9.7)

61-220

Mount Grant ††

282,907

(699,079)

45,786

(113,139)

9.6 (5.0, 11.0)

4.4 (1.3, 7.0)

12-220

Bodie††

141,490

(349,630)

105,698

(261,187)

17.3 (12.3, 20.0)

13.1 (9.7, 16.7)

137-512

South Mono

234,508

(579,482)

138,123

(341,311)

15.6 (12.3, 19)

13.3 (11.0, 16.7)

172-418

White Mountains

709,768

(1,753,875)

53,452

(132,083)

2 + (not available)

2 + (not available)

Not available

Total (all PMUs combined)

1,830,972

(4,524,430)

526,188

(1,300,238)

64.6 (41.9, 76.0)

41.4 (29.3, 56.8)

427-1,409

* BSLPG (2004, pp. 11, 32, 63, 102, 127, 153).

** Bi-State TAC (2012, unpublished data); BLM (2014, unpublished data).

*** Derived from Mathews et al. 2018, Table 6 and Figure 17.

**** Derived from NDOW and CDFW lek databases. Low and high counts occurred in 2008 and 2012, respectively. However, there was variation in annual peak male counts across PMUs; therefore, column does not sum to total.

† Active—two or more strutting males during at least 2 years in a 5-year period.

†† Part of the North Mono population segment in some early population analyses.

Sage-grouse populations in the Bi-State area appear to be isolated to varying degrees from one another (Casazza et al. 2009, entire; Oyler-McCance and Casazza 2011, p. 10; Tebbenkamp 2012, p. 66; Oyler-McCance et al. 2014, p. 8; Tebbenkamp 2014, p. 18). Birds in the White Mountains PMU as well as those in the South Mono PMU are largely isolated from sage-grouse populations in the remainder of the Bi-State DPS (Casazza et al. 2009, pp. 34, 41; Oyler-McCance and Casazza 2011, p. 10; Tebbenkamp 2012, p. 66). Traditionally, the Pine Nut PMU was presumed isolated; however, recent data show birds are capable of moving south into the Sweetwater Mountains in the Desert Creek-Fales PMU and even further south into the Bodie PMU (USGS 2014b, entire). It is not apparent that birds leaving the Pine Nuts are returning. While adults are unlikely to switch breeding populations, it is likely that genetic material is transferred among these northern populations through the natural movements of young of the year birds, as long as there are established populations available in which to emigrate. However, fine-scale genetic differentiation among sage-grouse populations is at a relatively small geographic scope (approximately 10 km (6 mi)), suggesting dispersal among populations is highly restricted (Jahner et al. 2016, pp. 8-9).

Two independent genetic evaluations have concluded there are three or four (Oyler-McCance et al. (2014, p. 8) or five (Tebbenkamp 2014, p. 18) unique genetic clusters in the Bi-State area. The latter study did not evaluate the Pine Nut population (Pine Nut PMU), which has been found to be unique (Oyler-McCance et al. 2014, p. 8). Based on this information, we presume that there are likely three to six populations or groups of birds in the Bi-State area that largely operate demographically independent of one another.

Four separate statistical approaches to assessing the population trend of the Bi-State DPS have been conducted, with two of these approaches being repeated following additional years of data collection. The four approaches are: (1) Connelly et al. 2004; (2) WAFWA 2008, (3) Garton et al. (2011 and 2015); and (4) U.S. Geological Survey (USGS) 2014, 2018, and 2019 (Coates et al. 2014, Coates et al. 2018, Mathews et al. 2018; Coates et al. 2020). In 2004, WAFWA conducted a partial population trend analysis for the Bi-State area (Connelly et al. 2004, chapter 6). The WAFWA recognizes four populations of sage-grouse in the Bi-State area, which represent the same overall extent delineated by the six PMUs described in the 2012 BSAP and this document. Two of the WAFWA populations (North Mono Lake and South Mono Lake) had sufficient data for trend analysis (Connelly et al. 2004, pp. 6-60 to 6-62). The North Mono Lake population encompasses the Bodie, Mount Grant, and Desert Creek-Fales PMUs, while the South Mono Lake population encompasses the South Mono PMU. The North Mono Lake population displayed a significant negative trend from 1965 to 2003, and the South Mono Lake population displayed a positive numerical trend, albeit not statistically significant, over this same period (Connelly et al. 2004, pp. 6-69 to 6-70). In 2008, WAFWA (2008, Appendix D) conducted a trend analysis on the same two populations identified above using a different statistical method for the periods from 1965 to 2007, 1965 to 1985, and 1986 to 2007. The trend for the North Mono Lake population, as measured by maximum male attendance at leks, was negative from 1965 to 2007 and 1965 to 1985, but variable from 1986 to 2007; results suggest an increasing trend beginning in about 2000. Results for the South Mono Lake population suggested a negative trend from 1965 to 2007, a stable trend from 1965 to 1985, and a variable trend from 1986 to 2007; these results also suggest a positive trend beginning around 2000.

In 2011, Garton et al. (2011, pp. 324-330) used a new approach to conduct a third trend analysis on the same populations used in the two previous WAFWA analyses. In this study, the average number of males per lek in the

North Mono Lake population declined by 35 percent and the average number of males per active lek declined by 41 percent from the 1965-1969 to 2000-2007 assessment periods (Garton et al. 2011, p. 324). Based on a reconstructed minimum population estimate for males from 1965 to 2007, the overall population showed irregular fluctuations between peaks in 1970 and 1987 of 520 to 670 males, with lows above 100 and no consistent long-term trend over the 40-year period. In the South Mono Lake population, the average number of males per lek increased by 218 percent from the 1965-1969 to 1985-1989 assessment periods but declined by 49 percent from the 1985-1989 to 2000-2007 assessment periods (Garton et al. 2011, p. 325). Based on reconstructed minimum male counts, the population showed no obvious trend through time with between 200 and 600 males attending leks. The average annual rate of change for both populations suggested that population growth has been, at times, both positive and negative over the past 40 years (Garton et al. 2011, pp. 324-330).

In 2015, the researcher updated this analysis by accumulating and analyzing several years of additional of data (Garton et al. 2015, entire). The updated estimates of population performance largely remained unchanged, while the outlook for persistence improved. For the North Mono Lake population, the estimated minimum number of males increased by 25 percent in 2013 as compared to 2007, while the probability of declining below a (researcher-defined) quasi-extinction threshold decreased (Garton et al. 2015, pp. 13-14). For the South Mono Lake population, the estimated minimum number of males decreased by six percent in 2013 as compared to 2007, although the probability of declining below the quasi-extinction threshold remained generally unchanged. For both populations, the predicted population size in 30 and 100 years increased in 2013 as compared to 2007 (Garton et al. 2011, pp. 376-377; Garton et al. 2015, p. 45). This approach suggests both of these populations will remain relatively small, as they have historically. Modeled weighted probabilities of either population declining below an effective population sizes of 50 individuals in 30 and 100 years are generally low (approximately 8 percent in 30 years and 22 percent in 100 years for both populations; Garton et al. 2015, p. 14).

In 2014, the USGS completed an analysis of population trends in the Bi-State area spanning the years 2003 to 2012 (Coates et al. 2014, entire). This analysis, termed an Integrated Population Model (IPM), integrates a variety of data such as lek counts and vital rates to inform an estimate of lambda (population growth) within the DPS. This analysis evaluated several populations in the Bi-State area including the Pine Nuts (Pine Nut PMU), Fales (California portion of the Desert Creek-Fales PMU), Desert Creek (Nevada Portion of the Desert Creek-Fales PMU), Bodie Hills (Bodie PMU), Parker Meadows (South Mono PMU), and Long Valley (South Mono PMU). It did not evaluate the populations in the Mount Grant or White Mountains PMUs due to data limitations. Results at that time suggested a stable trend in population growth across the entire Bi-State area between 2003 and 2012 (

i.e.,

both increasing and decreasing at an equal rate; Coates et al. 2014, p. 19). However, the trend in population growth was variable among populations (Coates et al. 2014, pp. 14-15).

Since the 2013 proposed rule and the 2015 withdrawal of the proposed listing rule, this analysis has been updated, once using a 13-year dataset spanning the years 2003 through 2015, again using 15 years of data spanning the years 2003 through 2017, and most recently using an approach that segmented the trends into three time intervals (Coates et al. 2018, entire; Mathews et al. 2018, entire; Coates et al. 2020, p. 8). The later approach was adopted to account for population cycling in sage-grouse; that is, regular periods of growth and decline naturally experienced by sage-grouse rangewide (Garton et al. 2011, p. 338). Indeed, it became apparent after analyzing the 13-year and 15-year datasets that the resulting estimates of population growth rates were being biased low due to an overrepresentation of down cycle years. To alleviate this bias, the latest trend analysis analyzes three time intervals that span one, two, and three cycles, with the start and stop points occurring in the troughs of a cycle. The three time intervals are 1995-2018, 2001-2018, and 2008-2018. Not all populations had sufficient historical data to evaluate all three time periods and thus analysis was constrained to one or two time periods depending on the population. The most recent analysis includes results from the Mount Grant and White Mountains PMUs, which were previously excluded due to insufficient data.

The results of the most recent iteration of the IPM suggests a general pattern of population cycling within an otherwise stable population across the Bi-State DPS with additional evidence that oscillations were influenced by drought conditions in recent years (Coates

et al.

2018, pp. 250, 252; Coates et al. 2020, p. 27). Furthermore, variation among individual PMU trends was apparent. The credible intervals (CRIs) reported in this study represent the range of interannual variation in lambda; that is, while annual median population growth for the Bi-State DPS as a whole in the period 1995-2019 is 1.018 (or approximately a 2 percent annual increase), the CRI reported (0.737-1.418) represents the variation in estimated lambda as it cycles from low to high over the study period, rather than the error in the median estimate for any given year.

As discussed above, this analysis estimated that, across the Bi-State as a whole, estimated median population growth was 1.018 (CRI = 0.737-1.418) from 1995 through 2018, 0.989 (CRI = 0.677-1.343) from 2001 through 2018, and 0.988 (CRI = 0.704-1.304) from 2008 through 2018 (Coates et al. 2020, Table 3). More specifically, over the past decade only the Bodie Hills and Parker Meadows population demonstrated an average annual positive growth (lambda = 1.061 and lambda = 1.048, respectively). The remaining populations including Mount Grant (lambda = 0.989), Fales, (lambda = 0.965), Pine Nut (lambda = 0.835), Desert Creek (lambda = 0.938), Long Valley (lambda = 0.96), and the White Mountains (lambda = 0.85; Coates et al. 2020, Table 3) averaged slight negative growth, although in each case the 95 percent CRI overlapped 1. Additional analysis suggests that over the past 5 years performance of some individual leks in Long Valley, Fales, Bodie Hills, Mount Grant, and to a lesser extent Sagehen (a population in the South Mono PMU) have been trending (negatively) in a pattern that deviates from the Bi-State at large (Coates et al. 2020, Table 3). This analysis suggests that alternative factors (such as anthropogenic disturbance) and not climate or weather may be acting to influence these specific sites.

In general, these four approaches (with some being run more than once) suggest that the trend in population growth within the Bi-State has fluctuated over the past 40 years (both increased and decreased), but over the entire timeframe has remained relatively stable. It appears that some populations (Pine Nut, Mount Grant, Bodie and Desert Creek) display greater variation in population growth (both positive and negative) and that trends among populations are variable (WAFWA 2008, Appendix D; Garton et al. 2011, p. 324, Coates et al. 2020, p. 34). Differences in

population trends across the same time periods in the newest study (compared to previous studies) may be due to the fact that the previous studies did not correct for the effects of population cycling (Coates et al. 2020, p. 30).

Two studies forecasted the probability that some populations would become extirpated. Garton et al. (2015, p. 41) used their reconstructed male counts to forecast future probabilities of population persistence assuming that past conditions persist into the future (a potentially unrealistic assumption). They conclude that the probabilities of declining below a quasi-extinction threshold (as defined by less than 50 breeding adults per population) were approximately 8 and 22 percent over the next 30 and 100 years, respectively, for both the North Mono Lake and South Mono Lake populations. Furthermore, Garton et al. (2015, p. 41) indicate that long-term persistence (as defined by more than 500 breeding adults per population, a standard number for persistence studies) for both core populations has an estimated 100 percent probability of dropping below this 500-adult threshold in the next 30 years. However, the researchers acknowledge the cyclic nature of sage-grouse populations and note that these populations have already been both above and below this mark in previous years, which is part of that natural cycling. Furthermore, model projections suggest that, both over the near term (30 years) and the long term, the North Mono Lake and South Mono Lake populations have a relative high probability of maintaining between 50 and 500 breeding adults. Thus, in these two core populations immediate genetic concerns (

e.g.,

inbreeding depression) are not apparent, but concern over maintaining long-term genetic and demographic viability remains.

Coates et al. (2020, p. 41; Table 1) estimated 10-year extirpation probability based on the number of runs of the IPM where populations went to zero. Probabilities of extirpation ranged greatly for individual PMUs and populations within the PMUs, with highest extirpation probabilities in the Pine Nuts PMU (69.7 percent), the White Mountains PMU (75.1 percent), and the Sagehen and Parker Meadows populations of the South Mono PMU (74.8 and 64.3 percent, respectively) (Coates et al. 2020, Table 1). The Bi-State DPS as a whole has a 1.1 percent extirpation probability in the next 10 years, and the Desert-Creek Fales PMU (9.0 percent), the Bodie Hills PMU (2.4 percent), and the South Mono PMU as a whole (3.8 percent), as well as its largest population (Long Valley; 7.9 percent) all have low probabilities of extirpation (Coates et al. 2020, Table 1). Some of these extirpation probabilities are lower than those calculated by Garton et al. (2015), likely because of differences in methods. The two studies also used different data sets, with Garton et al. (2015) using reconstructed male counts, and Coates et al. (2020) using multiple data sources for the IPM, including demographic and lek count data.

Thus, even though some populations in this most recent model have high probabilities of extirpation over the next ten years, the DPS as a whole is likely to persist over this time period. These extinction probabilities are created from continuing and forecasting past trends into the future, and thus likely do not reflect the effects of conservation measures started or completed in recent years.

Finally, the most recent population study included a PMU distribution analysis to examine short-term changes in population distribution across the Bi-State DPS. This analysis concluded that some parts of the Bi-State DPS are contracting, with the greatest contractions in acres of occupied habitat occurring in the Pine Nut, Fales, Sagehen, and White Mountains populations (Coates et al. 2020, p. 51-54). However, distributional area in the Bodie Hills is increasing (Coates et al. 2020, p. 54). As a whole, the Bi-State DPS showed some evidence of range contraction between 2008 and 2018, though the 95 percent CRI overlapped zero ((−0.07 [−0.19, 0.07]) (Coates et al. 2020, p. 51).

Following are brief accounts of each PMU.

(1) The Pine Nut PMU has the fewest sage-grouse (Median = 33; CRI = 0-73 individuals in 2018; Coates et al. 2020, p. 33) and the least number of active leks of the Bi-State PMUs. The population in the Pine Nut PMU has some level of connectivity with the Desert Creek-Fales PMU and potentially also with the Bodie and Mount Grant PMUs. The most significant impacts in this PMU are wildfire, invasive species, woodland encroachment, urbanization, and infrastructure.

Historically, a single lek in the northern portion of the Pine Nut Mountains (known as Mill Canyon Dry Lake) was the only known consistently active lek in this PMU. From 2000 through 2013, the average male attendance at the Mill Canyon Dry Lake lek was approximately 14 males (Bi-State TAC 2012, p. 17). Since 2013, activity on this lek has essentially ceased. An additional lek in the southern extent of the Pine Nut mountain range has periodically been reported but at this point is not considered active. Aerial surveys over the past few years typically detect birds in this area but actual strutting activity is uncertain. It is unclear if this southern lek has been abandoned, or if the original documentation just captured a rare event or simply misclassified random bird sightings for actual strutting activity. Over the past several years, two newly discovered lek sites in the Buckskin Range appear to be the only reliably active strutting grounds in this PMU (NDOW 2018, unpublished data). Both lek sites are small with two to five males apiece. The most recent results from the IPM suggests population growth in this PMU has declined on average six percent annually over the past decade (2008-2018; Median λ = 0.835; CRI = 0.234-1.94; Coates et al. 2020, p. 41).

Ongoing conservation efforts in this PMU include an acquisition of land containing high priority targets identified in the 2012 BSAP, which will help limit the effects of urban and exurban development. This 5,870 ha (14,500 ac) acquisition by the Carson City BLM has been approved and is anticipated to finalize in the spring of 2020. Other completed, ongoing, or planned conservation actions in the Pine Nut PMU include pinyon-juniper removal, horse gathers, removal of nonnative invasive plants, fuel reduction treatments, road closure, and fence removal (Bi-State TAC 2019, entire).

(2) The Desert Creek-Fales PMU straddles the Nevada-California border and contains two populations, one in each State. This PMU includes two breeding complexes: Desert Creek (Nevada) and Fales (California). The populations in the Desert Creek-Fales PMU have some level of connectivity with the Pine Nut PMU and potentially also with the Bodie and Mount Grant PMUs. The most significant impacts in this PMU are wildfire, invasive species (specifically conifer encroachment), infrastructure, and urbanization.

The NDOW uses data from six active leks to evaluate the trend and to tally maximum male attendance in the Desert Creek breeding complex. The long-term average male attendance is approximately 17.7 males per lek (Bi-State TAC 2017, p. 8). This average is influenced by one of these leks becoming inactive, with no males counted within the last 8 years. This lek might have moved locations, but this possibility remains unconfirmed. In 2012, a previously undocumented lek was discovered to the east of Nevada State Route 338 near Dalzell Canyon; 24

males were documented strutting on this lek. Over the last 7 years, this lek has remained active but counts have been small (<5). Three additional lek sites have also been discovered over the past 5 years. The most recent results from the IPM suggest population growth in this PMU has declined in the past decade. Estimated median population abundance in 2018 was 325 (CRI = 163-542; Coates et al. 2020, p. 34) individuals. Estimated median population growth from 2001 through 2018 was 0.939 (CRI = 0.348-1.499) and from 2008 through 2018 was 0.938 (CRI = 0.337-1.535; Coates et al. 2020, p. 34).

The Fales breeding complex is located in northern Mono County, California. It is composed of three active and three inactive leks. Two active leks are located near Sonora Junction, in proximity to the intersection of Highway 395 and California Highway 108, and one additional lek is located in the northeast corner of Mono County in the Sweetwater Mountains. No males have been documented on a previously occupied lek since possible activity in 2012 (CDFW 2014a, unpublished data; CDFW 2018, unpublished data). In 2018, peak male count on the two remaining leks was at a historic low of 16 males total. One of the two remaining leks may also potentially be affected by the recent Boot fire (2018) and the construction of a new outbuilding approximately 200 meters (218 yards) away. The most recent results from the IPM suggest population growth has been negative over the past decade, but evidence of decline is less robust than in other breeding areas, especially when considering the longer timeframes. Estimated median population abundance in 2018 was 121 (CRI = 54-208; Coates et al. 2020, p. 34) individuals. Estimated median lambda from 1995-2018 was 0.999 (CRI = 0.59-1.641), from 2001-2018 was 0.984 (CRI = 0.539-1.525), and from 2008-2018 was 0.965 (CRI = 0.544-1.397; Coates et al. 2020, p. 34). Overall, the combined Desert Creek and Fales subpopulation has declined 4.5 percent annually over the past 18 years (Coates et al. 2020, Table 3).

Completed, ongoing, and planned conservation measures in this PMU include pinyon-juniper removal, fence removal, road closures, livestock management (to reduce impacts to critical brood-rearing habitat), nonnative invasive plant removal, road closure, fence removal, and post-fire restoration (Bi-State TAC 2019, entire).

(3) The Mount Grant PMU is composed of three connected areas: Two high-elevation areas associated with Aurora Peak and the Wassuk Range (centered on Mount Grant), and one low-elevation area called Ninemile Flat (located in the East Fork Walker River valley) between the two high-elevation areas. This PMU is also connected with the Bodie PMU (a portion of the sage-grouse population in each PMU moves seasonally to the other). Surveys in the Mount Grant PMU have been sporadic due to difficulty accessing several locations and survey data collection has been influenced by apparent confusion over lek names and potential vagaries in lek locations. Woodland succession, and potentially to a lesser extent historical and current mining activity, has most negatively influenced bird distribution within the Mount Grant PMU (Bi-State TAC 2012, pp. 36-37). More recently, recreational OHV use has become a more prevalent activity under consideration for its influence on birds (Service 2020, p. 27).

The largest known lek in the Mount Grant PMU is located near Aurora Peak along the Nevada-California border, and it is generally considered the eastern extension of the Bodie PMU breeding complex. The high count of 94 males for this lek was recorded in 2006, with a low of 10 in 2013. Over the past 5 years, peak male counts have ranged between 14 and 41 individuals (NDOW 2018, unpublished data). Leks in the Wassuk Range have not been surveyed consistently due to lack of access, which requires aerial survey methods. In 2005 and 2006, a total of 19 and 33 males, respectively, were counted on five active leks in the Wassuk Range (NDOW 2009, unpublished data; Bi-State TAC 2012, p. 35). During 2012, on four leks surrounding Mount Grant, researchers counted a total of 139 birds (males and females) (BSLSP 2012, p. 13). In 2013, researchers counted 38 males on 3 leks, the largest of which contained 30 males, and over the past 4 years, total male counts have ranged between 8 and 35 across 3 to 5 leks, with the largest lek containing 23 males. However, these results are calculated from limited data due to access limitations and survey method. The most recent results from the IPM suggest population growth in this PMU has generally been stable over the past decade, largely mirroring the pattern across the Bi-State DPS overall. Estimated median population abundance in 2018 was 374 (CRI = 205-619; Coates et al. 2020, p. 34) individuals. Estimated median lambda from 2008 through 2018 was 0.989 (CRI = 0.551-1.536; Coates et al. 2020, p. 34).

Completed, ongoing, and planned conservation measures in this PMU include pinyon-juniper removal, sagebrush restoration, horse gathers (roundup and removal of wild horses on public lands), road closures, and fence removal (Bi-State TAC 2019, entire).

(4) The Bodie PMU contains one population (Bodie Hills), which is one of the two core (largest) populations for the Bi-State DPS. Most of the PMU is located to the east of Highway 395, but a small portion extends west of Highway 395 to the Sierra Nevada Mountains. Loss of historical sage-grouse range in the Bodie PMU has been most influenced by woodland succession (The Nature Conservancy 2009, entire; Bi-State TAC 2012, p. 30; USGS 2012, unpublished data). Significant stands of pinyon pine and to a lesser extent juniper occur at mid to low elevations on all flanks of the Bodie Hills as well as across the Sierra Nevada Mountains side of the PMU. Perennial water and meadow habitats in the Bodie PMU are generally privately owned and provide important sage-grouse habitat during the brood-rearing/summer season. While natural vegetation succession processes (woodland establishment)—in the absence of disturbance—have resulted in loss of sagebrush habitat that continues to fragment and isolate the population within this PMU, the extent of habitat loss and fragmentation attributable to land use change (urban development and agricultural conversion) appears minimal.

Approximately eight leks have been regularly surveyed in the Bodie PMU since the late 1980s with some locations being counted as far back as the 1950s. Additional active leks and numerous satellite leks (sites used sporadically in years of high sage-grouse abundance) have also been identified in the Bodie PMU. The majority of leks are located in the Bodie Hills east of Highway 395, but at least one long-term lek and several associated satellite leks occur west of the Highway. Since 1953, the long-term average total male attendance in the Bodie PMU is 192 (Bi-State TAC 2017, p. 11). The minimum count recorded was 64 males on 6 leks in 1998, and the maximum was 524 males on 14 leks in 2014.

The sage-grouse population in the Bodie PMU has no discernible long-term trend (Garton et al. 2011, p. 324; referred to as the Mono Lake population). The average number of males per active lek declined by 41 percent between 1965 and 2007, but since 1991 the minimum number of males counted has been trending upward (Garton et al. 2011, p. 324). Recent survey years are encouraging because they demonstrate a substantial increase in the peaks associated with the population fluctuations. These increasing peaks, coupled with the

general increase in the number of males counted since the early 1990s, suggests the Bodie PMU may be moving toward a cycle that oscillates at generally higher numbers as compared to the other PMUs. The most recent results from the IPM suggest growth in this population has remained stable, with evidence of increase. Estimated median population abundance in 2018 was 1,521 (CRI = 1,181-1,941; Coates et al. 2020, p. 34) individuals. Estimated median lambda from 1995 through 2018 was 1.07 (CRI = 0.76-1.758), from 2001 through 2018 was 1.029 (CRI = 0.74-1.457), and from 2008 through 2018 was 1.061 (CRI = 0.783-1.471; Coates et al. 2020, p. 34). Changes in population from 1995 through 2018 indicate that sage-grouse numbers as of 2018 were approximately four times higher compared to the low point 24 years ago (Coates et al. 2020, p. 34).

Completed, ongoing, and planned conservation measures in this PMU include pinyon-juniper removal; conservation easements; fence modification and removal; road closure; post-fire rehabilitation; and sagebrush and brood-rearing habitat restoration (Bi-State TAC 2019, entire).

(5) The South Mono PMU comprises three generally discrete locations or breeding complexes: Long Valley, Parker Meadow, and Granite Mountain. In the South Mono PMU, sage-grouse were likely historically distributed in many of the same areas utilized today (BSLPG 2004, p. 162), although there has been an estimated reduction in sagebrush extent of approximately 13 percent (USGS 2012, unpublished data) due to woodland succession. In addition, loss and fragmentation of habitat due to other causes (infrastructure, wildfire, and water development) has likely altered sage-grouse occurrence in certain locations such as the Mono Basin and Adobe Valley. In Long Valley, there may be specific locations where distribution has been reduced, but these areas appear limited in extent and confined to peripheral locations within the breeding complex. Changes in the sage-grouse population size in the Parker Meadow and Granite Mountain portions of the PMU are unclear, but likely greater. The Granite Mountain and Adobe Valley area (north of Highway 120) contains an expanse of sagebrush habitat and has been known to support birds during severe winters as well as historically (USFS 1966, p. 4; BSLPG 2004, p. 161). However, no consistent use of Adobe Valley is currently occurring, and use of the Granite Mountain area is limited. This inconsistent use is presumed to be caused by the general lack of water and meadow habitat in the area, which has likely decreased in the past century. To the east of Adobe Valley in the vicinity of Pizona Creek, a potential connectivity corridor exists between populations in the South Mono and White Mountains PMUs. However, the vegetation within this corridor has apparently changed due to woodland succession, and an aerial survey suggests that current vegetation is not suitable sage-grouse habitat (BSLSP 2012, p. 36).

Although surpassed by the Bodie PMU in 2012, traditionally the South Mono PMU has had the highest estimated population size as compared to the other PMUs within the range of the Bi-State DPS. The Long Valley breeding complex includes at least 10 to 12 consistently active leks and associated satellite sites located along the upper Owens River drainage and the Crowley Lake Basin. The Granite Mountain breeding complex includes two inactive leks located in the Adobe Valley and two active leks located in the Sagehen Summit area. The Parker Meadow breeding complex includes one consistently active lek site located south of Parker Creek at the northwest end of the June Lake Loop Road. Both the Granite Mountain and Parker Meadow breeding complexes are small, with generally less than 10 strutting males per complex documented per year.

Long Valley represents the largest population in the South Mono PMU and, in conjunction with the Bodie PMU, these two PMUs represent the core populations of the Bi-State DPS. Sage-grouse have been counted in the Long Valley breeding complex since the early 1950s. Historical maximum male attendance counts occurred in 1962, 1963, 1986, and 2012 when 408, 405, 406, and 418 male were counted, respectively, on 6-7 leks (Bi-State TAC 2012, p. 44). The long-term average peak male attendance between 1953 and 2018 is approximately 200, counted on an average of 9 leks. The high count during this period was 418 males in 2012, and the low count was 130 males in 2019 (CDFW 2019, unpublished data). The population in Long Valley has demonstrated positive and negative growth rates over the past 40 years (Garton et al. 2011, p. 329), although fluctuations have been relatively tempered and the population trend appears generally stable based on these data. The most recent results from the IPM suggest growth in this population has declined on average approximately four percent annually over the past decade, with more evidence of decrease than increase and apparently deviating from the remainder of the DPS. Estimated median population abundance in 2018 was 818 (CRI = 614-1,053; Coates et al. 2020, p. 35) individuals. Estimated median lambda from 1995 through 2018 was 0.996 (CRI = 0.676-1.427), from 2001 through 2018 was 0.986 (CRI = 0.655-1.433), and from 2008 through 2018 was 0.96 (CRI = 0.68-1.361; Coates et al. 2020, p. 35).

Four leks are known to exist in the Granite Mountain breeding complex (Adobe, Gaspipe, Big Sand Flat, and Sagehen Summit). Estimated median population abundance in 2018 was 20 individuals (CRI = 0-75; Coates et al. 2020, Table 1). Estimated median lambda from 1995 through 2018 was 0.916 (CRI = 0.282-1.964), from 2001 through 2018 was 0.844 (CRI = 0.18-1.819), and from 2008 through 2018 was 0.834 (CRI = 0.222-1.658; Coates et al. 2020, Table 3). Sage-grouse have been known to occur in the Parker Meadow breeding complex area since the 1950s, although lek monitoring did not occur until 2002. One small lek is active, and on occasion, satellite sites have experienced strutting activity (CDFW 2012, unpublished data). Since 2002, a high count of 18 males occurred in 2018, and a low count of 3 males occurred in 2010 (Bi-State TAC 2012, p. 45; CDFW 2018, unpublished data). The most recent results from the IPM suggest growth in this population is generally stable. Estimated median population abundance in 2018 was 48 (CRI = 21-86; Coates et al. 2020, Table 1) individuals. Estimated median lambda from 2001 through 2018 was 0.968 (CRI = 0.254-0.7.16), and from 2008 through 2018 was 1.048 (CRI = 0.361-5.814; Coates et al. 2020, Table 3). While growth in this population has little influence on the South Mono PMU as a whole, Parker Meadows likely facilitated connectivity between the Bodie and South Mono PMUs historically and potentially still does so today.

In 2017, an experimental translocation program was initiated to bolster low numbers in the Parker Meadows population (Mathews et al. 2018, p. 7). Given its infancy, the efficacy of this program has not yet been determined. However, the recent high male lek count in 2018 (which excluded translocated males) offers some optimism as translocations in 2017 improved reproductive success and ultimately recruitment in 2018.

Apart from the translocation, completed, ongoing, and planned conservation measures in this PMU include pinyon-juniper removal, land acquisition, road closures, landfill removal, and fence modification and removal (Bi-State TAC 2019, entire).

(6) The White Mountains PMU is the southernmost PMU in the Bi-State DPS, encompassing the White Mountains along the border of Nevada and California. It extends from the Candelaria Hills and Truman Meadows areas in the north to California Highway 168 in the south and from California Highway 6 in the west to the Silver Peak Range, Nevada, in the east. Historical and current distributions of sage-grouse in the White Mountains are not well understood. The area is difficult to access and, due to elevation, heavy snow conditions are typical during the spring breeding season. In addition, the number, size, and activity of leks in the White Mountains are not well known due to infrequent and opportunistic surveys. Historical accounts in Esmeralda County, Nevada, suggest bird densities there have likely always been low.

Current impacts such as exurban development (

e.g.,

Chiatovich Creek area (BSLSP 2012, p. 38)), grazing, recreation, and invasive species may be influencing portions of the population and are likely to increase in the future, but current impacts are considered minimal due to the remote locations of most known sage-grouse use areas. Potential future impacts from infrastructure (power lines, roads) and mineral developments could lead to fragmentation of the remote, contiguous nature of the habitat if conservation efforts were not conducted.

There are currently two active leks in the Nevada portion of the White Mountains PMU. Both were discovered in 2012 and are relatively small with between zero and nine males documented per lek per year (NDOW 2018, unpublished data). Since 2016, no males have been detected at one of these sites.

The most recent run of the IPM suggests more evidence of decline than increase, although this estimate is derived from fairly limited data. Estimated median population abundance in 2018 was 45 (CRI = 9-86; Coates et al. 2020, p. Table 1) individuals. Estimated median lambda from 2008 through 2018 was 0.85 (CRI = 0.343-1.957; Coates et al. 2020, p. Table 3).

Completed, ongoing, and planned conservation measures in this PMU include conservation easements and horse gathers (Bi-State TAC 2019, entire).

Regulatory and Analytical Framework

Regulatory Framework

Section 4 of the Act (16 U.S.C. 1533) and its implementing regulations (50 CFR part 424) set forth the procedures for determining whether a species is an “endangered species” or a “threatened species.” The Act defines an endangered species as a species that is “in danger of extinction throughout all or a significant portion of its range,” and a threatened species as a species that is “likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.” The Act requires that we determine whether any species is an “endangered species” or a “threatened species” because of any of the following factors:

(A) The present or threatened destruction, modification, or curtailment of its habitat or range;

(B) Overutilization for commercial, recreational, scientific, or educational purposes;

(C) Disease or predation;

(D) The inadequacy of existing regulatory mechanisms; or

(E) Other natural or manmade factors affecting its continued existence.

These factors represent broad categories of natural or human-caused actions or conditions that could have an effect on a species' continued existence. In evaluating these actions and conditions, we look for those that may have a negative effect on individuals of the species, as well as other actions or conditions that may ameliorate any negative effects or may have positive effects.

We use the term “threat” to refer in general to actions or conditions that are known to or are reasonably likely to negatively affect individuals of a species. The term “threat” includes actions or conditions that have a direct impact on individuals (direct impacts), as well as those that affect individuals through alteration of their habitat or required resources (stressors). The term “threat” may encompass—either together or separately—the source of the action or condition or the action or condition itself.

However, the mere identification of any threat(s) does not necessarily mean that the species meets the statutory definition of an “endangered species” or a “threatened species.” In determining whether a species meets either definition, we must evaluate all identified threats by considering the expected response by the species, and the effects of the threats—in light of those actions and conditions that will ameliorate the threats—on an individual, population, and species level. We evaluate each threat and its expected effects on the species, then analyze the cumulative effect of all of the threats on the species as a whole. We also consider the cumulative effect of the threats in light of those actions and conditions that will have positive effects on the species, such as any existing regulatory mechanisms or conservation efforts. The Secretary determines whether the species meets the definition of an “endangered species” or a “threatened species” only after conducting this cumulative analysis and describing the expected effect on the species now and in the foreseeable future.

Our proposed rule described “foreseeable future” as the extent to which we can reasonably rely on predictions about the future in making determinations about the future conservation status of the species. The Service since codified its understanding of foreseeable future in 50 CFR 424.11(d) (84 FR 45020). In those regulations, we explain the term “foreseeable future” extends only so far into the future as the Service can reasonably determine that both the future threats and the species' responses to those threats are likely. The Service will describe the foreseeable future on a case-by-case basis, using the best available data and taking into account considerations such as the species' life-history characteristics, threat-projection timeframes, and environmental variability. The Service need not identify the foreseeable future in terms of a specific period of time. These regulations did not significantly modify the Service's interpretation; rather they codified a framework that sets forth how the Service will determine what constitutes the foreseeable future based on our long-standing practice. Accordingly, though these regulations do not apply to this determination for the Bi-State DPS of greater sage-grouse because it was proposed prior to their effective date, they do not change the Service's assessment of foreseeable future for the Bi-State DPS of greater sage-grouse as contained in our proposed rule and in this determination.

Analytical Framework

The Species Report documents the results of our comprehensive biological status review for the species, including an assessment of the potential threats to the species. The Species Report does not represent a decision by the Service on whether the species should be proposed for listing as an endangered or threatened species under the Act. It does, however, provide the scientific basis that informs our regulatory decisions, which involve the further application of standards within the Act and its implementing regulations and policies. The following is a summary of

the key results and conclusions from the Species Report; the full report can be found at either Docket No. FWS-R8-ES-2018-0106 or Docket No. FWS-R8-ES-2018-0107 on

http://www.regulations.gov.

In this determination, we used the three conservation biology principles of resiliency, redundancy, and representation to assess the viability of the Bi-State DPS (Shaffer and Stein 2000, pp. 306-310). Briefly, resiliency supports the ability of the species to withstand environmental and demographic stochasticity (for example, wet or dry, warm or cold years), redundancy supports the ability of the species to withstand catastrophic events (for example, droughts, large pollution events), and representation supports the ability of the species to adapt over time to long-term changes in the environment (for example, climate changes). In general, the more resilient and redundant a species is and the more representation it has, the more likely it is to sustain populations over time, even under changing environmental conditions. Using these principles, we will consider the DPS' overall response to threats and the DPS' viability as a whole.

Summary of Biological Status and Threats

In this discussion, we review the biological condition of the species and its resources, the influence of those conditions on the species' overall viability, and the risks to that viability. Following are summary evaluations of 11 threats analyzed in the Species Report for the Bi-State DPS: Urbanization and habitat conversion (Factor A); infrastructure (Factor A); mining (Factor A); grazing and rangeland management (Factor A); nonnative invasive plants and native woodland succession (Factor A); wildfires and altered fire regime (Factor A); climate change, including drought (Factor A); recreation (Factor E); disease (Factor C); predation (Factor C); and small population size and population isolation (Factor E). We also evaluate the inadequacy of existing regulatory mechanisms (Factor D) on the magnitude of threats. Please see the Species Report (Service 2020, pp. 39-136) for a more detailed discussion of each threat.

In the Species Report, we also considered four additional threats: Renewable energy (Factor A), commercial and recreational hunting (Factor B); scientific and educational uses (Factor B); and contaminants (including pesticides) (Factor E). We concluded that though these threats are currently having some impact on individual sage-grouse and their habitat, their overall effect now and into the future is expected to be minimal. Therefore, we will not present summary analyses of those threats in this document but will consider them in our overall conclusions of impacts to the species. For full descriptions of all these threats and how they impact the species, please see the Species Report (Service 2020, pp. 63-124).

For the purposes of this assessment, we consider the foreseeable future to be the amount of time on which we can reasonably determine a likely threat's anticipated trajectory and the anticipated response of the species to those threats. For some threats impacting the Bi-State DPS, we consider the time for which we can reliably project threats and the anticipated response to be 30 years. This time period represents our best professional judgment of the foreseeable future conditions related to climate change, native woodland succession, nonnative invasive plants, and wildfire cycles, as well as the Bi-State DPS population cycles, probability of population persistence analyzed and described by Garton et al. (2015, entire), and regeneration time of sagebrush habitat. For other threats and the anticipated species response, we can reliably project impacts and the species response for less than 30 years, such as infrastructure, urbanization and habitat conversion, grazing and rangeland management, recreation, disease, and predation.

Urbanization and Habitat Conversion

Urbanization and habitat conversion (Factor A) have both direct and indirect effects on sagebrush habitat. In this section, we will discuss direct impacts to sagebrush habitat and to sage grouse populations. Indirect effects (such as those associated with infrastructure, increases in invasive plant species, and increases in domestic animals and wildlife predator species) will be addressed in later sections.

Traditional land use in the Bi-State area was primarily farming and ranching operations. These operations can have both beneficial and detrimental effects on sage-grouse conservation. Continuing farming and ranching operations have limited development of exurban subdivisions in the Bi-State area, but they have also affected the extent of remaining sagebrush through conversion to alternate vegetation types (such as pasture grass) (Service 2020, p. 35). The extent of impacts from the conversion of habitat depends on the amount of sagebrush lost, the type of seasonal habitat affected, and the arrangement of habitat lost (large blocks or small patches) (Knick et al. 2011, pp. 208-211).

While conversion of sagebrush vegetation communities to agricultural land continues to occur in the Bi-State area, the rate of this conversion remains difficult to quantify. Some reports state that conversion has lessened and that some of these lands are instead being sold and converted to low-density residential housing developments (Bi-State TAC 2012, pp. 18, 24, 41). Several studies have demonstrated that these increases in human population density could have strong effects on sage-grouse occupancy beyond the areas directly converted to human development. Sage-grouse extirpation was more likely in areas having a human population density of at least four people per 1 km

2

(10 people per 1 mi

2

) (Aldridge et al. 2008, pp. 991-992). Increase in human populations from this moderate level did not infer a greater likelihood of extirpation, likely because much of the additional growth occurred in areas no longer suitable for sage-grouse (Aldridge et al. 2008, pp. 991-992). Additionally, human density is 26 times greater in extirpated sage-grouse areas than in the currently occupied range (Wisdom et al. 2011, p. 463). In modeling several measures of human population on greater sage-grouse persistence, including current population density, historical population density, and human population growth, the best predictor of sage-grouse extirpation was human population density in 1950 (Aldridge et al. 2008, p. 985). This finding suggests that human development has had long-term impacts on habitat suitability and sage-grouse persistence (Aldridge et al. 2008, pp. 991-992). Thus, even small increases in human population density can have a strong effect on sage-grouse populations.

Another indicator of human development pressure on sage-grouse can be inferred from existing sagebrush availability. To persist in an area, sage-grouse require a minimum of 25 percent sagebrush; a high probability of persistence required 65 percent sagebrush or more (Aldridge et al. 2008, p. 990; and Chambers et al. 2014, p. 12). When data were analyzed in 2014 across the Bi-State, no leks contained less than 25 percent sagebrush cover in the immediate area. However, 30 out of the 55 leks (55 percent) contained between 25 and 65 percent sagebrush cover, suggesting an intermediate probability of persistence (Chambers et al. 2014, p. 12). The remaining 25 leks (45 percent)

contained greater than 65 percent sagebrush cover surrounding a lek site.

Historical and recent alterations, as well as ongoing conversion of sagebrush vegetation to support ranching operations and urban/exurban expansion, poses the greatest risk to persistence of sage-grouse in the Pine Nut, Desert Creek-Fales, and South Mono PMUs and to a lesser degree in the Bodie, and White Mountains PMUs (BSLPG 2004, pp. 24-169; Bi-State TAC 2012, pp. 18-46). Approximately 11 percent of suitable sage-grouse habitat in the Bi-State area occurs on private lands. In each PMU, sage-grouse home ranges include private lands that are critical to fulfilling annual habitat needs (Casazza 2009, p. 9), including a significant proportion of mesic areas (

e.g.,

upland meadows) within the range of the Bi-State DPS needed by sage-grouse during the late brood-rearing period. Sage-grouse are known to display strong site fidelity to traditional seasonal habitats, and loss or degradation of specific sites (especially brood-rearing habitat) can have negative population impacts.

The majority of local agency land in the South Mono PMU is owned by the City of Los Angeles and managed by the Los Angeles Department of Water and Power (LADWP). Many of these parcels are irrigated pasture, which provide important brood-rearing habitat to upwards 40 percent of the entire Bi-State DPS population. The LADWP is considering altering the extent to which these lands are irrigated. If realized, this potential additive stressor has the potential to negatively affect brood-rearing success (an influential demographic vital rate), given that the Long Valley population has demonstrated slightly negative population growth on average over the past 10 years. To address this concern, in 2019 LADWP provided a letter to the Service that reaffirms its prior commitment to allocate a sufficient amount of water to maintain sage-grouse habitat in Long Valley. Determining the amount of water needed to achieve this commitment will be informed by a collaborative, science-based approach (LADWP 2019,

in litt.

). The goal of LADWP's natural resource management is to employ Best Management Practices for land and water uses that maintain water supplies to the City of Los Angeles while protecting water quality, habitat, biodiversity, as well as species recognized under the ESA throughout the related watersheds. In 2014 (August 18, 2014), LADWP and their governing Board of Water and Power Commission approved a Conservation Strategy for the Bi-State DPS on their lands in Mono County, California. A component of this Strategy included commitments to maintain sage-grouse lekking, nesting, and brood rearing habitat. Consistent with this Strategy, LADWP has consistently managed the activities on their lands such as habitat restoration, livestock grazing, recreation, control of noxious and invasive weeds, fire suppression, infrastructure, and management of water in a manner that is compatible with the conservation of the Bi-State DPS. These past efforts and ongoing commitments will continue to provide benefits to conservation of the species. The remainder of private lands in the South Mono PMU is rangeland, although potential for commercial, residential, or recreational development exists.

Ongoing efforts to develop fee acquisition of properties or enroll them into conservation easements may help ameliorate current and anticipated effects of urbanization and habitat conversion. We estimate that approximately 10,415 ha (25,737 ac) of private land, which may provide suitable habitat for sage-grouse in the Bi-State DPS, are currently enrolled in various easement programs. The easements are targeted primarily at development and water rights and vary in length from 30 years to in perpetuity; thus, they can ameliorate the threat of development but do not necessarily ensure that habitat remains suitable. The majority of these easement lands are located in the Bodie PMU, with the remainder of easements occurring in the Desert Creek-Fales, South Mono, Pine Nut, and White Mountains PMUs. Of the approximately 60,326 ha (149,071 ac) of private land that may provide suitable habitat for sage-grouse within the Bi-State area, approximately 17 percent is under easements. An additional approximate 9,045 ha (22,352 ac) of previously private land within the Bi-State DPS has been acquired by State and Federal agencies over the past decade. In total, approximately 19,460 ha (48,089 ac) of land, either through conservation easements or acquisitions, has been substantially protected from urbanization challenges. These acres represent approximately 31 percent of total private lands containing suitable sage-grouse habitat across the Bi-State area. In addition, approximately 7,280 ha (18,000 ac) of lands identified as important by the 2012 BSAP have funding obligated and are working through the easement development process, with many of these efforts anticipated to be completed in a few years. An effort to acquire approximately 5,867 ha (14,500 ac) of additional lands in the Pine Nut PMU by the Carson City BLM has been approved but will likely not finalize until sometime in 2020. Combining the realized and reasonably anticipated efforts, approximately 57 percent of high-priority private lands in the Bi-State area will be protected.

Currently, 89 percent of the Bi-State DPS is Federal lands. On Federal lands, existing regulatory mechanisms protect sagebrush habitat from development. Approximately 54 percent of all lands within the sage-grouse Bi-State area is BLM-administered land; this includes approximately 1 million ha (2.5 million ac). The Federal Land Policy and Management Act of 1976 (43 U.S.C. 1701

et seq.

) is the primary Federal law governing most land uses on BLM lands, and directs development and implementation of resource management plans (RMPs) that direct management at a local level. The sage-grouse is designated as a sensitive species on BLM lands in the Bi-State area (Sell 2010, pers. comm.). The BLM's objectives for sensitive species is two-fold: (1) To conserve and recover ESA-listed species and the ecosystem on which they depend so that ESA protections are no longer needed, and (2) to initiate proactive conservation measures that reduce or eliminate threats to species to minimize the likelihood of and need for listing of these species under the ESA (BLM 2008, p. 3).

The USFS manages approximately 35 percent of the land in the Bi-State area or approximately 600,000 ha (1.5 million ac). Management of activities on national forest system lands is guided principally by the National Forest Management Act (NFMA). The NFMA specifies that the USFS must have a land resource management plan (LRMP) (16 U.S.C. 1600) to guide and set standards for natural resource management activities on each National Forest or National Grassland. The greater sage-grouse is designated as a USFS Sensitive Species in the Intermountain (R4) and Pacific Southwest (R5) Regions, which includes the Humboldt-Toiyabe National Forest (Bridgeport and Carson Ranger Districts) and the Inyo National Forest in the Bi-State area. Designated sensitive species require special consideration during land use planning and activity implementation to ensure the viability of the species on USFS lands and to preclude any population declines that could lead to a Federal listing (USFS 2008, p. 21). In addition, sensitive species designations require analysis for any activity that could have an adverse impact to the species, including analysis

of the significance of any adverse impacts on the species, its habitat, and overall population viability (USFS 2008, p. 21). The specific protection that sensitive species status confers to sage-grouse on USFS lands is largely dependent on LRMPs and site-specific project analysis and implementation.

These regulatory mechanisms prevent urban development on Federal lands. Through NFMA, LRMPs, Federal Land Policy and Management Act, RMPs, and the On-Shore Oil and Gas Leasing Reform Act (1987; implementing regulations at 36 CFR part 228, subpart E), land-managing agencies have the authority to manage, prevent, restrict, or attach protective measures to mineral extraction, wind development, and other energy permits on Federal lands. Thus, some habitat loss due to these developments may still occur on Federal land. Despite this, regulatory mechanisms in place are overall reducing the magnitude of threats associated with urbanization and habitat conversion.

Historical and recent conversion of sagebrush habitat on private lands for agriculture, housing, and associated infrastructure within the Bi-State area has likely negatively affected sage-grouse distribution and population extent in the Bi-State DPS, thus potentially influencing current and future recovery opportunities in the Bi-State area. These alterations to habitat have been most pronounced in the Pine Nut and Desert Creek-Fales PMUs and to a lesser extent in the Bodie, South Mono, and White Mountains PMUs. Although only a subset of the 11 percent of suitable sage-grouse habitat that occurs on private lands could potentially be developed, conservation actions on adjacent public lands could be compromised due to the significant percentage of late brood-rearing habitat that occurs on the private lands. Furthermore, the influence of land development and habitat conversion on the population dynamics of sage-grouse is greater than a simple measure of spatial extent because of the indirect effects from the associated increases in human activity. These threats are not universal across the Bi-State area, but localized areas of impacts have been realized and additional future impacts are anticipated. Currently, approximately 31 percent of total private lands containing suitable sage-grouse habitat across the Bi-State area are enrolled under an easement program or have been acquired by Federal and State agencies, and this number will increase to 57 percent when combining additional efforts that are ongoing and reasonably likely to occur.

Urbanization was not considered a significant threat at the time of the 2013 proposed listing rule. Currently, the effects of urbanization are having a minimal impact on the resiliency of populations within the Bi-State DPS. Absent any protections or conservation measures, the magnitude of impacts could increase into the foreseeable future as unprotected private lands become further fragmented. However, due to protections associated with regulatory mechanisms, and in particular because of efforts to acquire important private lands associated with the BSAP, we conclude that the magnitude of effects associated with this threat and its potential impacts on population resiliency should not increase to a detrimental level.

The BSAP (Bi-State TAC 2012, entire) includes measures to counter effects such as urbanization and habitat loss. Because we have determined that the partially completed and future conservation measures/efforts will be implemented and effective (see Policy for Evaluation of Conservation Efforts When Making Listing Decisions, above), we believe that urbanization and human disturbance is not a significant impact on the species within the foreseeable future.

Infrastructure

We characterize infrastructure as features that assist or are required for human development or an associated action. We focus on five infrastructure features that are apparent in the Bi-State area and that have been implicated in impacting sage-grouse: Three linear features (roads, power lines, and fences) and two site-specific features (landfills and communication towers).

Infrastructure can have direct impacts on sage-grouse, such as mortality through collision with power lines or fences, or direct impacts on sagebrush, such as habitat fragmentation or habitat loss. Fragmentation of sagebrush habitat has been cited as a primary cause of the decline of sage-grouse populations because the species requires large expanses of contiguous sagebrush (Service 2020, p. 45). Estimating the impact of habitat fragmentation caused by infrastructure on sage-grouse is complicated by the nonrandom placement of these features and by time lags in species response to habitat changes (Garton et al. 2011, p. 371), particularly since these relatively long-lived birds continue to return to altered breeding areas (leks, nesting areas, and early brood-rearing areas).

Roads are a linear feature on the landscape that can contribute to habitat loss and avoidance of areas close to roads, create barriers to migration corridors or seasonal habitats, and increase human disturbance in remote areas (Service 2020, p. 46). Additionally, roads can provide corridors for predators to move into previously unoccupied areas. For some mammalian and avian species (such as common ravens (

Corvus corax

)), dispersal along roads and other linear features like power lines has greatly increased their distribution (Forman and Alexander 1998, p. 212; Knight and Kawashima 1993, p. 268; Forman 2000, p. 33; Connelly et al. 2004, p. 12-3). Road networks also contribute to the spread of nonnative invasive plants via introduced road fill, vehicle transport, and road maintenance activities (Forman and Alexander 1998, p. 210; Forman 2000, p. 32; Gelbard and Belnap 2003, p. 426; Knick et al. 2003, p. 619; Connelly et al. 2004, p. 7-25). Direct mortality of sage-grouse from vehicle collisions does occur (Patterson 1952, p. 81; Wiechman and Reese 2008, p. 3), but mortalities are typically not monitored or recorded. Additionally, roads can have impacts on sage-grouse behavior. For example, roads within 7.5 km (4.7 mi) of leks negatively influence male lek attendance (Service 2020, pp. 46-47). The mechanism by which road presence reduces male lek attendance is not entirely clear, but chronic noise may contribute to these decreases. Male sage-grouse rely on acoustical signals to attract females to leks (Gibson and Bradbury 1985, p. 82; Gratson 1993, p. 692). Therefore, if noise interferes with mating displays, and thereby female attendance, younger males will not be drawn to the lek and eventually leks could become inactive (Amstrup and Phillips 1977, p. 26; Braun 1986, pp. 229-230).

In general, locations associated with mineral development (Mount Grant PMU), recreational activity (Bodie and South Mono PMUs), and major travel corridors (Desert Creek-Fales PMU) have the most significant daily road traffic. Our analysis of the best available data in the Bi-State area documents that 54 out of 55 known active or pending leks are within 3 km (1.8 mi) or less of an existing minor road (such as dirt two-track roads). Furthermore, of the 55 known active or pending leks, 64 percent (n=35) are within 5 km (3.1 mi) of paved secondary highways (Service 2013c, unpublished data).

An extensive network of roads and trails currently occurs throughout the range of the Bi-State DPS. In the Bi-State area, all Federal lands have restrictions limiting off-road vehicular travel. In addition, road closures and

rehabilitation of redundant roads by USFS and BLM are occurring to benefit Bi-State DPS conservation (Service 2020, p. 49).

We anticipate limited additional road and trail development will occur within suitable and potentially suitable habitat in the Bi-State area based on recent land use plan amendments, USFS and BLM travel management plans, and our current understanding of travel management direction. However, because an extensive road and trail network already occurs throughout the Bi-State area and because roads are known to result in both direct and indirect impacts to sage-grouse, we anticipate some impacts to birds and leks in the future, although we are uncertain to what degree these potential impacts will affect populations in the Bi-State area.

Power lines can directly affect sage-grouse by posing collision and electrocution hazards (Braun 1998, pp. 145-146; Connelly et al. 2000a, p. 974). They can have indirect effects by decreasing lek recruitment, increasing predator presence, facilitating the invasion of nonnative invasive annual plants by creating soil conditions favorable to their spread, potentially acting as a barrier to movement, and ultimately negatively affecting population performance (Service 2020, pp. 50-52). Due to the potential spread of invasive species and facilitation of predator occurrence as a result of power line construction, the indirect influence power lines can have on vegetation community dynamics and species occurrence often extends out further than the physical footprint (Knick et al. 2011, p. 219). Recent research has demonstrated that power lines are influencing sage-grouse behavior, demographic vital rates, and population growth rates due to associated impacts from raven abundance and predation (Gibson et al. 2018, p. 17).

Power lines occur in all Bi-State PMUs, but the extent of exposure varies by location. Based on available data (generally restricted to transmission lines), we estimate approximately 210 km (130 mi) of existing power lines are present across suitable habitat in the Bi-State. Overall, approximately 21 percent of 55 active and pending leks in the Bi-State area are within 2 km (1.2 mi) or less of existing transmission lines and approximately 38 percent of active and pending leks are within 5 km (3.1 mi) or less of existing transmission lines (Service 2013c, unpublished data). This suggests a potential loss, due to sage-grouse avoidance, of approximately 25,200 ha (62,270 ac) of otherwise suitable habitat (Gillan et al. 2013, p. 307). These transmission lines have the potential to further negatively influence over 250,000 ha (617,700 ac) or approximately 47 percent of suitable habitat, assuming their presence leads to the increased presence of ravens and other predators (Gibson et al. 2018, p. 17). Given that the predator community population size likely fluctuates through time, the scale of this potential impact will likely vary. Therefore, we are uncertain to what degree these potential impacts will affect populations in the Bi-State area. Of ongoing concern, however, is the potential time lag in effects from construction of power lines, as ravens and other predators may not utilize those lines until several years after their construction.

We anticipate that while existing power lines will persist on the landscape in the future, new power lines will be limited to smaller distribution lines associated with expansion of urbanization on a portion of the private lands within and around the Bi-State area. Bi-State habitat is currently managed as a right-of-way avoidance area by Federal land managers, such that larger lines (>120 kilovolts) and associated facilities will not be authorized (outside of existing corridors; BLM 2016, p. 15; HTNF 2016, p. 13). In the Bodie PMU, one decommissioned power line has been removed (Bi-State TAC 2018).

Fences are used to delineate property boundaries and for livestock management (Braun 1998, p. 145; Connelly et al. 2000a, p. 974). The effects of fencing on sage-grouse include direct mortality through collisions, creation of predator perch sites, and habitat fragmentation (Service 2020, p. 55). Fences present a risk to sage-grouse in all Bi-State PMUs (BSLPG 2004, pp. 54, 80, 120, 124, 169) due to known fence collisions and their potential to degrade habitat quality.

Not all fences present the same direct mortality collision risk to sage-grouse. Collision risk factors include fencing design, landscape topography, and spatial relationship with seasonal habitats (Christiansen 2009, p. 2). Management methods can decrease the impact of fences on sage-grouse. Visual markers have been employed in some of the high-risk areas to make fences more readily seen by birds; this method does appear to substantially reduce mortality due to collisions. Markers have been installed on a total of approximately 101 km (63 mi) of fence across the Bi-State DPS since 2012. Recent land use plan amendments encourage evaluation of existing fences with respect to sage-grouse conservation and discourage new installations that may negatively affect sage-grouse and its habitat (BLM 2016, pp. 12, 15; HTNF 2016, p. 14).

Data on the total extent (length and distribution) of existing fences and new fence construction projects are not available for the Bi-State area. However, based on data contained within the

Greater Sage-grouse Bi-State Distinct Population Segment Forest Plan Amendment

(USFS and BLM 2014, p. 99), there is likely on the order of 650 km (400 mi) of existing fences across the entire DPS. While we expect fencing to continue and possibly expand in the future within every PMU in the Bi-State area, efforts associated with conservation and regulatory mechanisms are currently ongoing (and expected to continue into the future) to ameliorate some of their impacts (Bi-State TAC 2012, p. 5; BLM 2016, pp. 12, 15; HTNF 2016, p. 14). While direct mortality through collision may be minimized by these approaches, indirect impacts caused by predation and other forms of habitat degradation may remain. The overall severity of these impacts to the Bi-State DPS throughout its range is not known, but based on the best available data the impacts are widespread but minor.

Millions of birds are killed annually in the United States through collisions with communication towers (including cellular towers) and their associated structures (

e.g.,

guy wires, lights) (Shire et al. 2000, p. 5; Manville 2002, p. 10), although most documented mortalities are of migratory songbirds. In a comparison of sage-grouse locations in extirpated areas of their range (as determined by museum species and historical observations) and currently occupied habitats, proximity to cellular towers had a strong correlation with likelihood of extirpation, and the distance to cellular towers was nearly twice as far from grouse locations in currently occupied habitats than extirpated areas (Wisdom et al. 2011, p. 463). However, there was no information as to whether the towers were a factor in the extirpation of those areas, or if their presence was linked to other threats in those areas (Wisdom et al. 2011, p. 467).

Within the range of the Bi-State DPS, approximately eight communication towers have been constructed in the past decade (Federal Communications Commission (FCC) 2018, unpublished data); each PMU has at least one such facility located within occupied sage-grouse habitat. These eight sites are likely an underrepresentation of the actual number of tower sites within the Bi-State area, as tower facilities shorter than 61 m (199 ft.) above ground level are not required to register with the FCC

(FCC 2018, unpublished data). We are unable to determine if any sage-grouse mortalities have occurred as a result of collisions with registered or unregistered communication towers or their supporting structures, as most towers are not monitored, and those that are monitored lie outside the range of the species (Kerlinger 2000, p. 2; Shire et al. 2000 p. 19).

Based on regulatory mechanisms associated with existing land use plans as well as existing land designations (wilderness and wilderness study areas), which significantly restrict new communication site development, we do not expect many new facilities on federally managed land in the Bi-State area (BLM 1993, p. 18; BLM 2016, p. 13; HTNF 2016, pp. 42-43). However, we anticipate that existing communication towers will remain in place and potentially new communication towers will be added at existing tower sites. Typically, rights-of-way grants afforded these facilities are for 30 years, and would likely be renewed indefinitely. It is also probable that new communication towers will be developed on non-federally managed lands along existing Federal Highways and State Routes. Thus, future communication tower placements will most likely affect the Desert Creek-Fales and South Mono PMUs, potentially affecting sage-grouse habitat in those locations.

Municipal solid waste landfills and associated roads contribute to increases in synanthropic predators (predator species adapted to conditions created or modified by people) (Knight et al. 1993, p. 470; Restani et al. 2001, p. 403; Webb et al. 2004, p. 523). One landfill exists in the Bi-State area. The Benton Crossing Landfill in Mono County is located north of Crowley Lake in Long Valley on a site leased from the LADWP. Common ravens and California gulls (

Larus californicus

) heavily use the landfill (Coates 2008, pers. comm.; USGS 2017, p. 17). Sage-grouse nest success in Long Valley (South Mono PMU) was lower than in other PMUs within the Bi-State area (Kolada et al. 2009b, p. 1344), which may be attributable to increased avian predators subsidized by landfill operations (Casazza 2008, pers. comm.; USGS 2017, p. 74; Coates et al.. 2018, p. 256). At this time, the future closing of the landfill appears probable, as LADWP has stated that they do not intend to renew the lease and Mono County has been funding planning studies for relocation, but any action on relocation is unlikely before the lease expires in 2023.

In the Bi-State area, linear infrastructure impacts each PMU both directly and indirectly to varying degrees. Existing roads, power lines, and fences may degrade sage-grouse habitat and contribute to direct mortality through collisions. In addition, roads, power lines, and fences influence sage-grouse use of otherwise suitable habitats adjacent to current active areas, increase predators, and increase invasive plants. The impact caused by these indirect effects extends beyond the immediate timeframe associated with the infrastructure installation. Across the entire range of the greater sage-grouse, the mean distance to highways and transmission lines for extirpated populations was approximately 5 km (3.1 mi) or less (Wisdom et al. 2011, p. 463). In the Bi-State area, 64 percent of active or pending leks are within 5 km (3.1 mi) of highways, and approximately 38 percent are within this distance to existing transmission lines (Service 2013c, unpublished data). The similarity apparent between these Bi-State DPS lek locations and extirpated greater sage-grouse populations suggests that persistence may be influenced by their juxtaposition with these anthropogenic features.

The geographic extent, density, type, and frequency of linear infrastructure disturbance in the Bi-State area have changed over time. While new development of some of these features (highways) will likely not occur, other infrastructure features have the potential of increasing (secondary roads, power lines, fencing, and communication towers). Furthermore, while development of new highways is unlikely, road improvements are possible and traffic volume will likely increase, and in certain areas these actions may be more important than road development itself.

We concluded in the 2013 proposed listing rule that infrastructure impacts (particularly fencing, power lines, and roads) were a significant factor for proposing to list the DPS as a threatened species, and today, we affirm that impacts from infrastructure occur in various forms throughout the Bi-State DPS's range and are an ongoing threat impacting population resiliency across its range and degrading habitat both currently and into the future. This conclusion is based on a variety of range-wide impacts that are currently occurring and expected to continue or increase in the future that result in habitat fragmentation; limitations for sage-grouse recovery actions due to an extensive road network, power lines, and fencing; and a variety of direct and indirect impacts such as direct loss of individuals from collisions or structures that promote increased potential for predation. Collectively, these threats may result in perturbations that influence both demographic vital rates of sage-grouse (

e.g.,

reproductive success and adult sage-grouse survival) and habitat suitability in the Bi-State area.

Importantly, conservation efforts that address infrastructure impacts have continued to be implemented since publication of the proposed listing rule, including (but not limited to): Removing power lines; implementing both permanent and seasonal road closures; removing racetrack fencing; and the likely relocation of the landfill in Long Valley. With continued implementation of conservation actions associated with the BSAP (Bi-State TAC 2012, entire), infrastructure-related impacts are significantly reduced.

The BSAP (Bi-State TAC 2012, entire) includes measures to counter negative effects from infrastructure. Because we have determined that the partially completed and future conservation efforts will be implemented and effective (see Policy for Evaluation of Conservation Efforts When Making Listing Decisions, below), we believe that effects associated with infrastructure may no longer be considered a significant impact into the future.

Mining

Surface and subsurface mining for mineral resources (gold, silver, aggregate, and others) can result in direct loss of sagebrush habitat. Construction of mining infrastructure can result in additional direct loss of habitat from establishment of structures, staging areas, roads, railroad tracks, and power lines. Sage-grouse and their nests could be directly affected by crushing or vehicle collision. Sage-grouse also can be impacted indirectly from an increase in human presence, land use practices, ground shock, noise, dust, reduced air quality, degradation of water quality and quantity, and changes in vegetation and topography (Moore and Mills 1977, entire). However, whereas theoretical effects are relatively clear and logical, information relating sage-grouse response to mineral developments is not extensive.

Mineral development is classified as leasable (fluid) minerals (in the Bi-State area, this is limited to geothermal resource), saleable minerals (sand and gravel pits), and locatable minerals (precious metals). Through existing regulatory mechanisms, Federal managers have discretion to condition or deny proponents of leasable or saleable mineral projects, and existing

land use management plans have provisions that significantly restrict the likelihood of these developments (BLM 1993, p. 18; BLM 2016, pp. 12-13; HTNF 2016, pp. 19-21). Locatable minerals are administered under the General Mining Act of 1872. Federal land managers have very limited ability to prevent or preclude these activities from occurring.

Mineral extraction has a long history throughout the Bi-State area. Mining continues today to a limited extent in all PMUs and is expected to continue into the future. Although mining occurs year-round in the Bi-State DPS, direct loss of key seasonal habitats or population disturbances during critical seasonal periods are of greatest impact. Currently, the PMUs with the greatest exposure are Bodie, Mount Grant, Pine Nut, and to a lesser degree South Mono (BSLPG 2004, pp. 89, 137, 178). There are currently several active Plans of Operations that overlap Bi-State sage-grouse habitat and thousands of active mining claims on Federal, State, and private lands. There is potential for additional mineral developments to occur in the Bi-State area in the future. While all PMUs have the potential for mineral development, based on current land designations and past activity, it appears the Pine Nut and Mount Grant PMUs are most likely to experience new activity (Service 2020, pp. 61-63). Currently operational mines are not within the core population areas of the Bi-State DPS, although existing inactive mining sites, exploration actions, and potential future developments could impact important lek complexes and population connectivity.

In general, potential exists for mining operations to expand both currently and into the future, but the scope of impacts from existing mining expansion is not considered extensive. We concluded in the 2013 proposed listing rule and reaffirm here that, by itself, mining is not currently considered a significant impact to the Bi-State population, though mining exploration continues, and mining activity could occur at any time in the future.

Conservation efforts that address the impacts from mining have continued to be implemented since publication of the proposed listing rule, such as reducing human-related disturbances (

e.g.,

road noise/traffic). The BSAP includes conservation actions targeting development and human disturbances that will reduce the minor or potential impacts from mining (Bi-State TAC 2012, entire). Because we have determined that the partially completed and future conservation efforts will be implemented and effective (see Policy for Evaluation of Conservation Efforts When Making Listing Decisions, below), we believe impacts associated with mining in the Bi-State population area are not a reasonably anticipated concern into the future.

Grazing and Rangeland Management

Livestock grazing continues to be the most widespread land use across the sagebrush biome (Connelly et al. 2004, p. 7-29; Knick et al. 2003, p. 616; Knick et al. 2011, p. 219), including within the Bi-State area. Links between grazing practices and population levels of sage-grouse are still not well defined (Braun 1987, p. 137; Connelly and Braun 1997, p. 231). Depending on timing and intensity, grazing can have both positive and negative impacts to greater sage-grouse populations. Sage-grouse populations responded favorably to higher grazing levels after peak vegetative productivity, but declined when grazed earlier (Monroe et al. 2017, p. 1102). Livestock grazing can reduce the available food sources needed during breeding and brood-rearing periods (Braun 1987, p. 137; Dobkin 1995, p. 18; Connelly and Braun 1997, p. 231; Beck and Mitchell 2000, pp. 998-1000). But while some studies have reported grass height as important for sage-grouse nesting habitat, others have reported weak or no effects, and other studies concluded no influential effects of grass-related variables on nesting success (Service 2020, pp. 65-66). In the Bi-State area, studies have suggested that grazing, or more importantly maintenance of residual grass cover, may not influence nest success in the Bi-State area as much as in other regions (Kolada et al. 2009b, pp. 1343-1344; Coates et al. 2017a, p. 55). This may be because the most prevalent nest predator in the Bi-State area, the common raven, is potentially less influenced by grass cover than mammalian predators (Coates et al. 2008, entire). Studies suggest that a threshold may exist whereby grazing can occur without detriment to sage-grouse resources. We note, however, the specifics of this threshold remain uncertain (Service 2020, p. 66).

Potential negative effects of livestock grazing on the sagebrush ecosystem include reduced water infiltration rates, reduced cover of herbaceous plants and litter, compacted soils, and increased soil erosion (Braun 1998, p. 147; Dobkin et al. 1998, p. 213). These impacts change the proportions of shrubs, grasses, and forbs in affected areas, and increase the propensity for invasion by nonnative invasive plant species (Service 2020, p. 67). Additionally, as far back as the mid-1900s, livestock grazing has been implicated in facilitating the spread of cheatgrass (Leopold 1949, p. 165; Billings 1951, p. 112). Livestock grazing reduces invasion resistance by imposing a competitive disadvantage on native herbaceous understory species and altering soil properties (Reisner et al. 2013, p. 10). While livestock grazing has been used strategically in sage-grouse habitat to control some invasive weeds (Merritt et al. 2001, p. 4; Olsen and Wallander 2001, p. 30; Connelly et al. 2004, p. 7-49) and woody plant encroachment (Riggs and Urness 1989, p. 358), there is limited evidence that controlling established cheatgrass through grazing is feasible. Rest from grazing may, in fact, be a more effective strategy of building resistance to invasion into a site (Reisner et al. 2013, p. 10). Collectively, these studies suggest managed livestock grazing at moderate intensities in the Bi-State area may be benign or even beneficial to some seasonal sage-grouse habitats, but when grazing intensity exceeds this moderate use level, livestock grazing can have negative effects on sage-grouse habitat and individuals (Boyd et al. 2014, p. 60).

Historically, extensive rangeland management has been conducted by Federal agencies and private landowners to reduce shrub cover and improve forage conditions for livestock in the sagebrush-steppe ecosystem (Connelly et al. 2004, p. 7-28; Knick et al. 2011, p. 220; Pyke 2011, p. 534). Today, ongoing removal or control of sagebrush in the Bi-State area is limited. The BLM and USFS have stated that, with rare exceptions, they no longer convert sagebrush to other habitat types, and that future treatments shall maintain, improve, or restore Bi-State sage-grouse habitat (BLM 2016, p. 11; HTNF 2016, p. 16). Federal land managers currently focus on improving the diversity of the native plant community, reducing conifer encroachment, or reducing the risk of large wildfires. On private lands in the Bi-State area, our understanding of sagebrush treatments is limited. Known instances of the elimination of sagebrush by chemical and mechanical means are apparent, but their extent remains to be quantified. The ability to restore or rehabilitate overgrazed areas depends on the condition of the area relative to its site potential (Knick et al. 2011, p. 232). Active restoration is required where the native understory is reduced (Pyke 2011, p. 539). If an area has soil loss or invasive species, returning the native plant community may be impossible (Daubenmire 1970,

p. 82; Knick et al. 2011, p. 232; Pyke 2011, p. 539).

Infrastructure related to livestock management such as water developments (

e.g.,

springs, tanks, guzzlers) and fences in shrub-steppe habitats are common on public lands (Connelly et al. 2004, p. 7-35). Development of springs and other water sources can artificially concentrate domestic livestock and wild ungulates in mesic areas, thereby exacerbating grazing and trampling impacts to sage-grouse nesting and brood-rearing areas (Braun 1998, p. 147; Knick et al. 2011, p. 230). Diverting water sources can result in the loss of riparian or wet meadow habitat that sage-grouse depend upon as sources of forbs and insects. However, water developments can also be beneficial to sagebrush vegetation communities, as this practice can help distribute livestock to water troughs and away from riparian areas, minimizing concentrated impacts of livestock grazing.

In the Bi-State area, there are 149 grazing allotments identified across all PMUs. Of these, 122 are considered active allotments, encompassing approximately 73 percent of suitable sage-grouse habitat. Most grazed lands are managed by the BLM and USFS, although much of the meadow habitats are located on private lands (BSLPG 2004, entire). Several rangeland health assessments (RHAs) or their equivalent have been completed on 120 allotments (104 that are active) and have not been conducted on the remaining 29 allotments (18 that are active). While there are public allotments or portions of allotments exhibiting adverse impacts from current or historical livestock grazing (

e.g.,

vegetation condition or composition is generally less than desired), our understanding is the majority of allotments in the Bi-State area are in good condition (Axtell 2008, pers. comm.; Murphy 2008, pers. comm.; Nelson 2008, pers. comm. BLM 2014b,

in litt.;

Bi-State TAC 2017, pp. 31-33), and livestock grazing is generally thought to have a limited impact on sage-grouse habitat (Bi-State TAC 2012, entire). Livestock grazing will continue into the indefinite future within the Bi-State area at its current or slightly decreased level, and thus remain a discretionary action where Federal agencies have the ability to alter use when renewing grazing permits. Also, it appears that Federal land managers are moving in a direction that affords greater discretion to sage-grouse habitat needs when evaluating livestock management and the majority of allotments have or will have pending renewals and associated terms and conditions that consider sage-grouse habitat, including the establishment or placement of infrastructure (Nelson 2008, pers. comm.; BLM 2016, pp. 11-12; HTNF 2016, pp. 16-18).

In addition to domestic livestock, feral horses can negatively impact meadows and brood-rearing habitats used by sage-grouse, and these impacts can be more severe given horses cannot be managed on a seasonal basis (Connelly et al. 2004, p. 7-37; Crawford et al. 2004, p. 11). Horse presence may negatively affect sagebrush vegetation communities and habitat suitability for sage-grouse by decreasing grass cover, fragmenting shrub canopies, altering soil characteristics, decreasing plant diversity, and increasing the abundance of invasive cheatgrass. In areas utilized by both horses and cattle, it is unknown whether grazing impacts are synergistic or additive (Beever and Aldridge 2011, p. 286). The most substantial impacts from feral horses in the Bi-State area occur in the Pine Nut, Mount Grant, and White Mountains PMUs (Axtell 2008, pers. comm.; Bi-State TAC 2012, pp. 19, 37, 41), although they are also known to occur within the Bodie and South Mono PMUs. We are unaware of the specific severity and scope of impacts caused by feral horses on the Bi-State DPS and sage-grouse habitat, although localized areas of concern in all PMUs are apparent. Most important are probable impacts to mesic areas within the Pine Nut, Mount Grant, and White Mountains PMUs. Management of herd size by Federal agencies is an ongoing challenge as horse management is expensive and often controversial. Based on this understanding, we anticipate future impacts caused by wild horses to increase, especially as horse herds are growing by 20 percent annually. However, despite this increase, the threat will have a minor impact on sagebrush habitat.

Existing regulatory mechanisms such as BLM land management plans and USFS LRMPs further reduce the magnitude of threats associated with grazing and rangeland management. For example, the Central California Standards and Guidelines of the Bishop RMP provide additional direction for the management of permitted livestock grazing on public lands administered by the Bishop Field Office. Standards are set for soil, species, riparian, and water quality, and metrics by which the achievement of these standards could be measured were established. This enables BLM to manage livestock grazing to ensure that species such as sage-grouse are “healthy and in numbers that appear to ensure stable to increasing populations; habitat areas are large enough to support viable populations or are connected adequately with other similar habitat areas.” Additionally, the Carson City District Land Use Plan Amendment for the Nevada and California Greater Sage-grouse Bi-State Distinct Population Segment addresses conservation of the Bi-State area by providing specific direction to management of the DPS and its habitat, including grazing management and wild horse and burro management (BLM 2016, entire). Numerous land use allocations restrict or substantially limit new habitat and bird disturbances and identify Best Management Practices to further minimize allowable actions. For more details on plans that address the impacts of grazing and rangeland management, see the Existing Regulatory Mechanisms of the Species Report (Service 2020, pp. 124-136).

Analyzing the overall impacts of grazing is difficult, as there is little direct evidence linking grazing effects and sage-grouse population responses. Analyses for grazing impacts at landscape scales important to sage-grouse are confounded by the fact that almost all sage-grouse habitat has at one time been grazed and thus no ungrazed control areas exist for comparisons (Knick et al. 2011, p. 232). Overall, impacts from historic grazing and current rangeland management occur within localized areas throughout the Bi-State DPS's range, though it is more pronounced in some PMUs than others. Domestic livestock and feral horses have the potential to negatively affect sage-grouse habitats by decreasing grass cover, fragmenting shrub canopies, altering soil characteristics, decreasing plant diversity, and increasing the abundance of invasive plant species, although their impacts and management potential can differ. Grazing and domestic livestock management has the potential to result in sage-grouse habitat degradation, though there is some conflicting information on whether some of the impacts of grazing are positive or negative. The Pine Nut and Mount Grant PMUs may be most sensitive to impacts from grazing as both PMUs are generally lower in elevation and receive less precipitation, making their sagebrush habitat less resistant to withstanding changes. Across the remainder of the PMUs, localized areas of meadow degradation are apparent, and these conditions may influence sage-grouse populations, as meadows are essential for recruitment of young.

Overall, impacts from past grazing and rangeland management occur within localized areas in all PMUs,

although impacts are more pronounced in some PMUs than others. We concluded in the 2013 proposed listing rule that grazing and rangeland management was a factor (albeit not significant) for proposing to list the DPS as a threatened species as a result of ongoing habitat degradation impacts that may affect sage-grouse habitat in the Bi-State area, resulting in an overall reduction in aspects of habitat quality (

e.g.,

fragmentation, lack of understory plants, increased presence of nonnative plant species), especially in the Pine Nut and Mount Grant PMUs. While we recognize that livestock and feral horses may negatively impact sage-grouse habitat, we affirm that it does not appear that this is a significant concern in the Bi-State area today.

Importantly, conservation efforts that address the impacts from grazing and rangeland management have continued to be implemented since publication of the proposed listing rule, including (but not limited to): (1) Completing drafts and beginning to implement the new BLM and USFS Land Use Plan amendments (U.S. Department of the Interior and USDA 2015, entire), which are a considerable improvement for conservation of the Bi-State DPS and its habitat; repairing watering facilities, irrigation structures, and fencing around natural riparian areas to control grazing activity; increasing monitoring and management of horse and burrow herds; and restoring meadow/riparian habitat in critical brood-rearing habitat areas. With continued implementation of conservation actions associated with the BSAP (Bi-State TAC 2012, entire), impacts from grazing and rangeland management are significantly reduced.

The BSAP (Bi-State TAC 2012, entire) includes measures to counter effects such as livestock and wild horse grazing. Because we have determined that the partially completed and future conservation efforts will be implemented and effective (see Policy for Evaluation of Conservation Efforts When Making Listing Decisions, below), we believe impacts associated with grazing and rangeland management are not a concern now or in the foreseeable future.

Nonnative Invasive Plants and Native Woodland Succession

Shifting vegetation communities within the Bi-State area are altering sagebrush habitat that supports sage-grouse. Nonnative invasive plants such as cheatgrass alter sagebrush community structure, composition, productivity, nutrient cycling, and hydrology (Vitousek 1990, p. 7). Nonnative plants may also cause declines in native plant populations through mechanisms such as competitive exclusion and niche displacement (Mooney and Cleland 2001, p. 5446). They can create long-term changes in ecosystem processes, such as altering fire cycles and other disturbance regimes; these changes can persist even after an invasive plant is removed (Zouhar et al. 2008, p. 33).

Nonnative plants degrade existing sage-grouse habitat, replacing vegetation essential to sage-grouse for food and cover (Connelly et al. 2000a, pp. 971-972; Miller et al. 2011, pp. 160-164). The presence of cheatgrass influences lek persistence, nest site selection, and ultimately population performance (Blomberg et al. 2012, p. 7; Knick et al. 2013, p. 1544; Lockyer et al. 2015, p. 791; Coates et al. 2016b, p. 12747). Nonnative plants affect sage-grouse habitat and population demographics both in the short term (

e.g.,

nest site selection, loss of forbs and associated insects) and in the long term (

e.g.,

population growth, sagebrush displacement and habitat fragmentation).

A variety of nonnative invasive plants are present within the Bi-State area, although cheatgrass is of greatest concern. Local managers and scientists consider cheatgrass to be a low-level threat across four PMUs (White Mountains, South Mono, Bodie, and Desert Creek-Fales), a moderate threat in the Mount Grant PMU, and a high threat in the Pine Nut PMU (Bi-State TAC 2012, pp. 19, 26, 32, 37, 41, 49). Areas of greatest concern are in the Pine Nut PMU where cheatgrass abundance is greatest and where there are restoration challenges following several recent wildfires. Averaged across the entire Bi-State, percent cover of cheatgrass is generally low (Peterson 2003, entire), and conversion to an annual grass dominated community is currently limited to only a few locations. Anecdotal reports suggest this assessment remains generally true, though it is apparent that the abundance and distribution of cheatgrass has increased over the past decade.

Efforts are ongoing to restore or rehabilitate sage-grouse habitat affected by nonnative plant species, but the techniques for accomplishing these efforts remain mostly unproven, experimental, and often logistically difficult (Pyke 2011, pp. 543-544). Regardless, restoration efforts such as localized weed treatments have been applied within all the Bi-State PMUs.

Based on our understanding and past experience with nonnative invasive species in the Great Basin Region, we anticipate that impacts from nonnative species will continue or increase into the future. According to a mapping of sagebrush habitats across the range of greater sage-grouse that categorized these habitats based on their resistance and resilience to disturbance, both resistance and resilience are low in the warm and dry sagebrush habitats contained within the Nevada portion of the Bi-State (Pine Nut, Mount Grant, and Desert Creek portion of the Desert Creek-Fales PMUs) and most of the South Mono PMU (Chambers et al. 2014, pp. 16-17). That is, these areas have lower productivity and higher susceptibility to cheatgrass or other invasive annual grass incursion and will therefore face greater restoration challenges should fire occur. In the wetter and cooler sagebrush habitats found in the White Mountains, Bodie, Fales portion of the Desert Creek—Fales PMUs, and high-elevation sites of the Mount Grant PMU, resilience and resistance were ranked as moderately high to high, implying these locations have greater productivity and are generally less suitable to invasive annual grass establishment (Chambers et al. 2014, p. 43).

In addition to nonnative plant invasions within sagebrush habitat, some native tree species are increasing in sagebrush habitat and impacting the suitability of the habitat for the various life processes of the sage-grouse. Pinyon-juniper woodlands are a native vegetation community that can encroach upon, infill, and eventually replace sagebrush habitat. The cause of this conversion from shrubland to woodland is debatable but may be due to a suite of causes acting in concert with active wildfire suppression including: Domestic livestock grazing (reduced competition from native grasses and forbs and facilitation of tree regeneration by increased shrub cover and enhanced seed dispersal), climatic fluctuations favorable to tree regeneration, enhanced tree growth due to increased water use efficiency associated with carbon dioxide fertilization, and recovery from past disturbance (natural and anthropogenic) (Miller et al. 2008, p. 10; Baker 2011, p. 200; Miller et al. 2011, pp. 167-169; Bukowski and Baker 2013, p. 560). Each of these factors have likely influenced the current pattern of vegetation in the Bi-State area today and have led to an estimated 40 percent decline in sagebrush extent due to woodland succession and isolation of sage-grouse populations across the DPS.

Land managers in the Bi-State area consider pinyon-juniper encroachment a substantial threat to sage-grouse because it impacts habitat quality, quantity, and connectivity, and

increases the risk of avian predation to sage-grouse populations (BSLPG 2004, pp. 20, 39, 96; Bi-State TAC 2012, pp. 18-47). Previously occupied sage-grouse locations throughout the Bi-State area are thought to have been abandoned due to woodland succession (Bi-State TAC 2012, pp. 18-47). The extent of the conversion to pinyon-juniper woodland varies by PMU, with the South Mono PMU being the least impacted (approximately 13 percent loss) and the Pine Nut PMU being the most influenced (approximately 50 percent loss). The remainder of the PMUs (White Mountains, Mount Grant, Desert Creek-Fales, and Bodie) are each estimated to have experienced approximately a 40 percent loss of historical sagebrush vegetation to woodland succession. In total, over the past 150 years, an estimated 390,000 ha (963,000 ac) of sagebrush habitat has converted to woodland vegetation, resulting in a loss of availability of total sagebrush habitat in the Bi-State area (which is not synonymous with suitable sage-grouse habitat as presented in Table 1) from slightly over 1,000,000 ha (2,580,000 ac) in 1850 to approximately 650,000 ha (1,600,000 ac) today across the Bi-State DPS (USGS 2012, unpublished data).

In order to counter the impact of pinyon-juniper encroachment, treatments to thin or remove woodland species are ongoing. Recent research supports previous assertions that these treatments would expand sage-grouse habitat and ultimately be used successfully by birds (Sandford et al. 2017, p. 63; Severson et al. 2017, p. 53; Olsen 2019, pp. 21-22). Sage-grouse response to woodland encroachment has been negative to the incursion but in some instances responsive to treatment actions. Sage-grouse encountering pinyon-juniper communities coupled with the rate of movement through these communities negatively affected bird survival (Prochazka et al. 2017, p. 46); however, sage-grouse readily nested in conifer treatment sites after trees had been removed (Severson et al. 2017, p. 53). Woodland treatments increased suitable available breeding habitat and enhanced nest and brood success (Sandford et al. 2017, p. 63). Sage-grouse avoided pinyon-juniper communities across varying degrees of community dominance; this avoidance increased survival (Coates et al. 2017b, pp. 31-33). Removal of pinyon-juniper trees encroaching into sagebrush vegetation communities can increase sage-grouse population growth through improving juvenile, yearling, and adult survival as well as improving nest survival (Olsen 2019, pp. 21-22). This research found population growth was 11.2 percent higher in treatment than in control sites within 5 years of conifer removal. Therefore, woodland encroachment into occupied sage-grouse habitat reduces, and likely eventually eliminates, sage-grouse occupancy. However, treatment action to remove trees increases sagebrush habitat, and these habitats are used successfully by sage-grouse.

Prior to the development of the BSAP in 2012, approximately 18 woodland thinning or removal projects had been undertaken, removing approximately 5,454 ha (13,479 ac) of woodland (Bi-State TAC 2012, p. 5). Since this time, an additional 81 projects have been initiated, treating approximately 18,798 ha (46,450 ac). While it is premature to detect a population-level response of sage-grouse to these treatments in the Bi-State region, increases in occupied habitat and increases in nest and brood success as well as survival parameters are anticipated based on recent research finding a positive overall outcome for population performance and connectivity (Coates et al. 2017b, pp. 31-33; Sandford et al. 2017, p. 63; Severson et al. 2017, p. 53; Olsen 2019, pp. 21-22). Furthermore, preliminary analysis of marked birds in the Bi-State area demonstrates grouse use of these treatments and offers support for these research findings (Mathews et al. 2018, pp. 33-34). Implementation and planning of additional woodland treatment projects are also under way over the next several years covering tens of thousands of acres.

Using the best available data, we estimate that the current acres of conifer removal treatments is within the range of estimated acres of woodland expansion and, further, that these treatments will continue based on ongoing commitments provided by land managers to implement the BSAP.

Overall, we consider woodland succession to pose a substantial threat to the Bi-State DPS. However, we consider impacts from woodland succession to be reduced by conservation measures with a high degree of implementation and effectiveness, recognizing that restoring historical connectivity and preventing further loss of suitable habitat requires continued focused active management.

Both nonnative invasive plants and native woodland succession are impacting the sage-grouse and its habitat in the Bi-State area. In general, nonnative plants are not abundant throughout the Bi-State area, with the exception of cheatgrass that occurs in all PMUs and is most extensive and of greatest concern in the Pine Nut PMU. Cheatgrass is a nonnative annual species that will likely continue to expand throughout the Bi-State region in the future and increase the adverse impact that currently exists to sagebrush habitats and sage-grouse through outcompeting beneficial understory plant species and altering the fire ecology of the area. Land managers have had limited success preventing cheatgrass invasion in the West, and elevational barriers to occurrence are becoming less restrictive. The best available data suggest that future conditions that could promote expansion of cheatgrass will be most influenced by precipitation and winter temperatures (Bradley 2009, p. 200). Cheatgrass is a serious challenge to the sagebrush shrub community, and its spread will be detrimental to sage-grouse in the Bi-State area. In addition, the encroachment of native woodlands (particularly pinyon-juniper) into sagebrush habitats continues to occur throughout the Bi-State area. Currently, however, treatment actions are on par with the expansion rate.

Overall, invasive nonnative and native plants occur throughout the entire Bi-State DPS's range. We concluded in the proposed listing rule that their spread was a significant factor for proposing to list the DPS as a threatened species based on the extensive amount of pinyon-juniper encroachment and cheatgrass invasion that is occurring throughout the DPS's range, and the interacting impact these invasions have on habitat quality (

e.g.,

reduces foraging habitat, increases likelihood of wildfire) and habitat fragmentation. Today, we affirm that nonnative and native invasive species occur throughout the Bi-State DPS's range and are significant threats to the species both currently and in the future. We expect this threat will increase across the range into the future unless it is actively managed.

Several regulatory mechanisms identified in existing federal land use plans address the impact of nonnative invasive plants and native woodland succession, the BSAP (Bi-State TAC 2012, entire) includes measures to counter the effects of these threats. In the past few years, we have gained increased certainty about the effectiveness of removal efforts for pinyon-juniper woodland. Because we have determined that the partially completed and future conservation efforts will be implemented and effective (see Policy for Evaluation of Conservation Efforts When Making Listing Decisions, below), the threat of native woodland succession is being reduced, though it is still impacting

sagebrush habitat throughout the DPS. Conservation measures are less effective at controlling and ameliorating the effects of nonnative invasive plants, and thus they will continue to affect sagebrush habitat into the foreseeable future.

Wildfires and Altered Fire Regime

Wildfire is the principal disturbance mechanism affecting sagebrush communities. The nature of historical fire patterns, particularly in big sagebrush, is not well understood; however, it was historically infrequent (Miller and Eddleman 2000, p. 16; Zouhar et al. 2008, p. 154; Baker 2011, pp. 189, 196). Most sagebrush species have not developed evolutionary adaptations such as re-sprouting and heat-stimulated seed germination found in other shrub-dominated systems, such as chaparral, that are exposed to relatively frequent fire events. Natural fire regimes and landscapes were shaped by a few infrequent large fire events; historical fire rotation was 50-200 years in mountain big sagebrush communities and 200-350 years in Wyoming big sagebrush communities (Baker 2011, p. 196; Bukowski and Baker 2013, pp. 556-558). In general, fire extensively reduces sagebrush within burned areas, and big sagebrush varieties, the most widespread species of sagebrush, can take decades to reestablish and even longer to return to pre-burn conditions (Service 2020, p. 79). While no specific studies have been conducted within the Bi-State area to inform our knowledge of fire rotation, we expect the pattern in Wyoming big sagebrush and mountain big sagebrush communities in the Bi-state area to be similar to those described above for the remainder of the species' range.

Both increases and decreases in the natural fire regime can have detrimental effects on sagebrush. When intervals between wildfire events become unnaturally long, woodlands can encroach into sagebrush communities as the prolonged interval between fires allows seedlings to establish and trees to mature (Miller et al. 2011, p. 167). Currently, active wildfire suppression continues to occur throughout the Bi-State DPS.

Conversely, the invasion and establishment of nonnative invasive annual grasses, such as cheatgrass and medusahead rye (

Taeniatherum caput-medusae)

can increase wildfire frequency within sagebrush ecosystems and negatively influence the likelihood of recovery (Zouhar et al. 2008, p. 41; Miller et al. 2011, p. 167; Balch et al. 2013, p. 178). Cheatgrass shortens historical fire patterns by providing an abundant and easily ignitable fuel source that facilitates fire spread and recovers within 1-2 years of a wildfire event, leading to a recurring wildfire cycle that prevents sagebrush reestablishment (Young and Evans 1978, p. 285; Eiswerth et al. 2009, p. 1324; Balch et al. 2013, pp. 180-181). It is difficult and usually ineffective to restore sagebrush after annual grasses become established due to the positive feedback with fire, invasive species seed bank establishment, and alterations to soil and hydrologic processes (Paysen et al. 2000, p. 154; Connelly et al. 2004, pp. 7-44-7-50; Pyke 2011, p. 539).

Fire can have direct impacts on sage-grouse and their habitat. If fire does not completely remove sagebrush, it can reduce suitable nesting habitat, herbaceous understory vegetation used for forage and cover by sage-grouse hens and chicks, and potentially insects used for feeding by chicks. Additionally, isolation and fragmentation of populations due to habitat losses from wildfire presents a higher probability of extirpation in disjunct areas (Knick and Hanser 2011, p. 395; Wisdom et al. 2011, p. 469). This is a concern within the Bi-State area, specifically throughout the Pine Nut and portions of the South Mono and Desert Creek-Fales PMUs where burned habitat may be influencing already small and disjunct populations. As areas become fragmented and isolated through disturbances such as wildfire, persistence may be hampered by the limited ability of individuals to disperse into areas that are otherwise not self-sustaining. Thus, while direct loss of habitat due to wildfire has been shown to be a significant factor associated with population persistence for sage-grouse (Beck et al. 2012, p. 452), the indirect effect posed by loss of connectivity among populations may greatly expand the influence of this threat beyond the physical fire perimeter (Knick and Hanser 2011, pp. 401-404).

Sagebrush recovery rates following wildfire are highly variable, and precise estimates are often hampered by limited data from older burns. Factors contributing to the rate of shrub recovery include the amount of and distance from unburned habitat, abundance and viability of seed in soil seed bank (sagebrush seeds are typically viable for one to three seasons depending on species), rate of seed dispersal, and pre- and post-fire weather, which influences seedling germination and establishment (Young and Evans 1989, p. 204; Maier et al. 2001, p. 701; Ziegenhagen and Miller 2009, p. 201). Full recovery to pre-burn conditions in mountain sagebrush communities ranges between 25 and 100 years, and in Wyoming big sagebrush communities potentially ranges between 50 and 120 years (Baker 2011, pp. 194-195). By 25 years post-fire, Wyoming big sagebrush typically has less than 5 percent pre-fire canopy cover (Baker 2011, p. 195).

Wildfire is considered a relatively high risk across all the PMUs in the Bi-State area due to its ability to affect large landscapes in a short period of time (Bi-State TAC 2012, pp. 19-49). Furthermore, the future potential of this risk is exacerbated by the presence of people, invasive species, and climate change. While numerous wildfires have occurred in the Pine Nut, and South Mono PMUs (fewer in the other PMUs) over the past 18 years, to date there have been relatively few large-scale events (Service 2020, Table 3). In general, current data also do not indicate an increase of wildfires in the PMUs over time with the exception of the Pine Nut PMU where fire occurrence is more frequent (Service 2018, unpublished data). Furthermore, cheatgrass has a more substantial presence in the Pine Nut PMU, which appears to mirror (much more than the rest of the Bi-State area) the damaging fire and invasive species cycle impacting sagebrush habitat across much of the Great Basin.

The loss of habitat due to wildfire across the West is anticipated to increase due to the intensifying synergistic interactions among fire, people, invasive species, and climate change (Miller et al. 2011, p. 184). The past- and present-day fire regimes across the sage-grouse's range have changed with a demonstrated increase of wildfires in the more arid Wyoming big sagebrush communities and a decrease of wildfire across many mountain sagebrush communities (Miller et al. 2011, pp. 167-169). Both altered fire regime scenarios have caused significant losses to sage-grouse habitat through facilitating conifer expansion at high-elevation interfaces and nonnative invasive weed encroachment at lower elevations (Miller et al. 2011, pp. 167-169). In the face of climate change, both scenarios are anticipated to worsen (Baker 2011, p. 200; Miller et al. 2011, p. 179), including in the Bi-State area. Predicted changes in temperature, precipitation, and carbon dioxide are all anticipated to influence vegetation dynamics and alter fire patterns, resulting in increasing loss and conversion of sagebrush habitats (Neilson et al. 2005, p. 157). Furthermore, climate scientists suggest that, in addition to the predicted change in climate toward a warmer and generally drier Great Basin, variability

of annual and decadal wet-dry cycles will likely increase and act in concert with fire, disease, and invasive species to further stress the sagebrush ecosystem (Neilson et al. 2005, p. 152, Ault et al. 2014, p. 7538). The anticipated increase in suitable conditions for wildland fire will likely further interact with people and infrastructure. Human-caused fires have increased and are correlated with road presence across the sage-grouse range (Miller et al. 2011, p. 171).

Based on the best available information, approximately 117 wildfire events have affected approximately 83,859 ha (207,220 ac) of sagebrush habitat across the Bi-State area since 2000, but conversion of sagebrush habitat to a nonnative invasive vegetation community has been largely restricted (Pine Nut PMU withstanding). It appears that a lack of historical fire has facilitated the establishment of woodland vegetation communities and loss of sagebrush habitat. Both the “too little” and “too much” fire scenarios present challenges for the Bi-State DPS. The former influences the current degree of connectivity among sage-grouse populations in the Bi-State DPS and the extent of available sagebrush habitat, likely affecting sage-grouse population size and persistence. The latter, under current conditions, now has the potential to quickly alter substantial percentages of remaining sagebrush habitat. Restoration of sagebrush communities is challenging, requires many years, and may be ineffective in the presence of nonnative invasive grass species. Research in the Great Basin found that sage-grouse habitat features are unlikely to occur in many burned areas even 20 years post-restoration (Arkle et al. 2014, p. 15).

Several regulatory mechanisms target the potential impact of wildfires and altered fire regime. Within the Bi-State area, participants in the BSAP (Bi-State TAC 2012, entire) have treated areas to reduce the threat of wildfire by using broadcast burns and mechanical treatment (

e.g.,

fuel breaks and conifer removal projects). To lower the risk of wildfire, approximately 1,806 ha (4,462 ac) of fuels reduction treatments have been conducted to remove conifers (Bi-State TAC 2018, unpublished data). Additionally, the reseeding of 7,699 ha (19,025 ac) from past fires has been completed. The efficacy of these treatments to achieve desired results is generally unknown.

Overall, the threat of wildfire and the existing altered fire regime occurs throughout the Bi-State DPS's range. We concluded in the proposed listing rule that significant impacts would be expected to continue or increase in the future based on a continued fire frequency pattern that exacerbates pinyon-juniper encroachment into sagebrush habitat in some locations, but also an increased fire frequency in other locations that promotes the spread of cheatgrass and other invasive species that in turn can hamper recovery of sagebrush habitat. Within the Bi-State DPS, the continued reduced fire frequency exacerbates pinyon-juniper encroachment into sagebrush habitat in some locations. However, an increased fire frequency in other locations promotes the spread of cheatgrass and other invasive species that in turn can hamper recovery of sagebrush habitats in other locations. While it is not currently possible to predict the extent or location of future fire events in the Bi-State area, we anticipate fire frequency to increase in the future due to the increasing presence of cheatgrass, human footprint, and the projected effects of climate change.

The BSAP (Bi-State TAC 2012, entire) includes measures to counter effects such as wildfire ignition risks and catastrophic fire. Fuels reduction projects and rehabilitation efforts post-wildfire have been and will continue to be implemented into the future to address the potential impacts from wildfire, including (but not limited to): Conducting conifer (pinyon-juniper) removal and conducting weed treatments for invasive, nonnative plants such as cheatgrass. Because we have determined that the partially completed and future conservation efforts will be implemented and effective (see Policy for Evaluation of Conservation Efforts When Making Listing Decisions, below), we conclude that impacts due to the threat of wildfires and altered fire regime have been reduced since the time of the 2013 proposed listing rule. We expect that, into the future, continued implementation of the BSAP will further reduce the impacts of wildfire and altered fire regime.

Climate

In considering future climate projections for the Bi-State area, we analyzed multi-model ensembles that made use of multiple greenhouse gas emission scenarios. In general, downscaled climate change model predictions in the Bi-State area tend to agree on an increasing temperature regime (Cayan et al. 2008, pp. S38-S40; He et al. 2018, p. 11; Gonzalez et al. 2018, Chapter 25) and stable to increasing local precipitation, with a shift in timing of local precipitation events (Diffenbaugh et al. 2005, p. 15776; Cayan et al. 2008, p. S28; He et al. 2018, p. 14: Reich et al. 2018, p. 21). The environment will be relatively drier due to elevated temperature, increased rates of evapotranspiration, more precipitation falling as rain instead of snow, and more frequent and prolonged drought (Neilson et al. 2005, p. 150; He et al. 2018, pp. 9, 11, 16). The precipitation variables are an important predictor of sagebrush occurrence as well as to greater sage-grouse occurrence, as timing and quantity of precipitation greatly influences plant community composition and extent—specifically forb production, which in turn affects nest and chick survival and ultimately population performance (Blomberg et al. 2012, p. 7; Coates et al. 2018, p. 252). Impacts associated with climate change may increase the magnitude of threats impacting the Bi-State DPS, as its effects interact with other stressors such as disease, invasive species, prey availability, moisture, vegetation community dynamics, disturbance regimes, habitat degradation, and habitat loss (Service 2020, p. 89).

Downscaled climate change projections in the Great Basin and Eastern Sierra also predict acceleration in fire frequency, with fires potentially becoming larger and more severe, and fire seasons becoming longer (Service 2020, pp. 87-88). Furthermore, drought frequency and persistence are anticipated to increase (Ault et al. 2014, p. 7545; Reich et al. 2018, p. 31; Gonzalez et al. 2018, entire). In the Bi-State area, drought is a natural part of the sagebrush ecosystem. Sage-grouse population performance in the Bi-State region responds to alterations in annual precipitation (Coates et al. 2018, p. 252; Coates et al. 2020, p. 27). While there is variation among subpopulations, on average findings suggest a 50 percent increase in precipitation corresponds to a 15.5 percent increase in population growth the following year. Moreover, these results indicate that precipitation needs to be approximately 20 percent greater than average for population recovery following drought, consistent with results from the Great Basin in the absence of wildfire (Coates et al. 2016b, p. 12747; Coates et al. 2018, p. 255).

Sage-grouse are affected by drought through the loss of vegetative habitat components, reduced insect production (Connelly and Braun 1997, p. 9), and potentially exacerbation of West Nile virus (WNv) and predation exposure (Gibson et al. 2017, p. 177; Prochazka et al. 2017, p. 47; Coates et al. 2018, p. 255). Drought reduces vegetation cover (Milton et al. 1994, p. 75; Connelly et al. 2004, p. 7-18), potentially resulting in

increased soil erosion and subsequent reduced soil depths, decreased water infiltration, and reduced water storage capacity. These habitat component losses can result in declining sage-grouse populations due to increased nest predation and early brood mortality associated with decreased nest and brood cover and food availability (Braun 1998, p. 149; Moynahan et al. 2007, p. 1781). Furthermore, there are known occasions where the reduced condition of brood-rearing habitat due to weather has resulted in little to no recruitment within certain PMUs (Bodie, Pine Nut) (Gardner 2009, pers. comm.; Coates 2012, pers. comm.).

Within the Bi-State area, several projects have been undertaken to improve meadows and riparian areas for sage-grouse that could help increase population resiliency in response to increasing frequency of drought. These projects include grazing exclosures, changes to grazing management plans, prescribed fires, invasive plant control, mechanical treatments, and conservation easements intended to improve the resiliency of meadow habitats on privately owned lands (Bi-State TAC 2018, unpublished data).

Climate change is not known to currently impact the Bi-State DPS to such a degree that the viability of the species is at stake, although climate change has been shown to influence the impact of drought and the annual water cycle and these in turn have been shown to influence grouse population performance in the Bi-State area (Coates et al. 2018, p. 251; Reich et al. 2018, pp. 31, 33). However, while it is reasonable to assume the Bi-State area will experience vegetation changes into the future (as presented above), we do not know the degree to which these changes will ultimately have impacts on the Bi-State DPS. An analysis conducted by NatureServe, which incorporates much of the information presented above, suggests a substantial contraction of both sagebrush and sage-grouse range in the Bi-State area by 2060 (Comer et al. 2013, pp. 142, 145).

Occurrence of cheatgrass has generally been restricted to elevations below approximately 1,700 m (5,500 ft.) above mean sea level (Bradley 2010, p. 202). More recently, this barrier appears less certain in the Bi-State area as cheatgrass occurs at elevations previously thought to be relatively unfavorable based on the grass's ecology. This situation suggests that few locations in the Bi-State area are immune to cheatgrass invasion. Climate change may strongly influence the spread of this species as the available climate data suggests changes in timing of precipitation and increasing winter temperatures favorable to this species (Bradley 2009, p. 200). Predictions on the timing, type, and amount of precipitation contain the greatest uncertainty. In the Bi-State area, model scenarios that result in the greatest expansion of cheatgrass suggest much of the area remains suitable to cheatgrass presence with some additional high-elevation sites in the Bodie Hills, White Mountains, and Long Valley becoming more suitable than they are today (Bradley 2009, p. 204). On the opposite end of the spectrum, model scenarios that result in the greatest contraction in cheatgrass range suggest low-elevation sites such as Desert Creek-Fales and Mount Grant PMUs become less suitable for this invasive species but high-elevation sites (Bodie and White Mountains PMUs), where habitat conditions are generally marginal today, become more suitable in the future.

Based on this information we assume that climate change (acting both alone and in concert with impacts such as wildfire and nonnative invasive species) could be pervasive throughout the range of the Bi-State DPS, potentially degrading habitat to such a degree that all populations would be negatively affected with some low-elevation sites or populations currently exposed to greater cheatgrass abundance (Pine Nut, Desert Creek-Fales, South Mono and portions of the Mount Grant PMUs). Therefore, given the scope and potential severity of climate change when interacting with other threats in the future, the overall impact of climate change to the Bi-State DPS at this time is considered moderate to high.

We concluded in the proposed listing rule that climate change will potentially act in combination with other impacts to the Bi-State DPS, further diminishing habitat and increasing population isolation, making the DPS more susceptible to demographic and genetic challenges or disease. Although no regulatory mechanisms are available that can ameliorate the effect of changing climate or increasing drought, ongoing implementation of various conservation measures in the BSAP increases the resilience of the habitat to the effects of threats exacerbated by climate change and drought, such as wildfire and invasive plants (

e.g.,

through removal of pinyon-juniper woodland). We expect that, into the future, continued implementation of the BSAP will further reduce the impacts of these threats associated with climate change.

Recreation

Recreational activities such as fishing, hiking, horseback riding, and camping, off-highway vehicle (OHV) use (including snowmobiles), and mountain biking occur throughout the range of the greater sage-grouse, including throughout the Bi-State DPS area. These activities can degrade wildlife resources, water, and land by distributing refuse, disturbing and displacing wildlife, increasing animal mortality, and decreasing diversity of plant communities (Boyle and Samson 1985, pp. 110-112).

The effects of OHV use on sage-grouse have not been directly studied (Knick et al. 2011, p. 219). However, sage-grouse avoidance of activities associated with development suggests they are disturbed by persistent human presence (Holloran 2005, pp. 43, 53, 58; Doherty et al. 2008, p. 194). Sage-grouse response to disturbance may be influenced by the type of activity, recreationist behavior, predictability of activity, frequency and magnitude, activity timing, and activity location (Knight and Cole 1995, p. 71). Disruption of sage-grouse during vulnerable periods at leks, or during nesting or early brood-rearing, could affect reproduction and survival (Baydack and Hein 1987, pp. 537-538).

Indirect effects to sage-grouse from recreational activities may include impacts to vegetation and soils and facilitation of the spread of invasive species. One study found long-term (2-year) reductions in sagebrush shrub canopy cover as the result of repeated OHV trips (Payne et al. 1983, p. 329). Increased sediment production and decreased soil infiltration rates were observed after disturbance by motorcycles and four-wheel drive trucks on two desert soils in southern Nevada; noise from these activities can also cause additional disturbance (Eckert et al. 1979, p. 395; Knick et al. 2011, p. 219; Blickley et al. 2012, p. 467). Unpaved roads fragment sagebrush landscapes and subsidize predators adapted to humans; they also provide disturbed surfaces that facilitate the spread of invasive plant species (Knick et al. 2011, p. 219).

Potential disturbance caused by non-motorized forms of recreation (fishing, camping, hiking, big game hunting, dog training) are most prevalent in the South Mono and Bodie PMUs. These PMUs are also exposed t

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