In Reply Refer to: FWS-SBR-INY-KRN-RIV-LA-15B0214-19F1036

September 30, 2019 Sent by Email Memorandum

To: District Manager, California Desert District, Bureau of Land Management, Moreno Valley, California

From: Acting Field Supervisor, Carlsbad Fish and Wildlife Office, Carlsbad, California

Subject: Biological Opinion for the West Mojave Route Network Project, San Bernardino, Inyo, Kern, Riverside, and Los Angeles Counties, California (6840 (P) LLCAD00000)

This document transmits the U.S. Fish and Wildlife Service’s (Service) biological opinion based on our review of the Bureau of Land Management’s (Bureau) proposed land use plan amendment under the West Mojave Route Network Plan and the final supplemental environmental impact statement. We will consider the effects of the proposed action on the federally listed desert tortoise [Mojave population distinct population segment (Gopherus agassizii)], Cushenbury milk-vetch (Astragalus albens), Cushenbury buckwheat (Eriogonum ovalifolium var. vineum), Cushenbury oxytheca (Acanthoscyphus parishii, Oxytheca pi var. goodmaniana), Parish’s daisy (Erigeron parishii), triple-ribbed milk-vetch (Astragalus tricarinatus), and Lane Mountain milk- vetch (Astragalus jaegerianus). You also requested formal consultation regarding critical habitat for these species. This document was prepared in accordance with section 7 of the Endangered Species Act of 1973 (Act), as amended (16 U.S.C. 1531 et seq.).

We based this biological opinion on information obtained from your final supplemental environmental impact statement for the proposed land use plan amendment (Bureau 2019b), a table of errata regarding revised data (Toedtli 2019), and other information in our files. We also coordinated closely with your staff during the development of the biological opinion. We can make a record of this consultation available at the Carlsbad Fish and Wildlife Office.

We have not repeated the citation of “Bureau 2019b” hereafter when we mention the final supplemental environmental impact statement. In addition, “Bureau 2019b” refers to the final supplemental environmental impact statement. 2

CONSULTATION HISTORY

The Bureau and Service consulted on various aspects of the California Desert Conservation Area Plan between 2002 and 2006. The Service’s (2006) biological opinion on the western Mojave Desert component of the California Desert Conservation Area Plan contains a detailed discussion of the history of these consultations; we are incorporating that discussion by reference.

During the 2006 consultation, the Bureau requested our concurrence that the proposed action, which included a revised access network for vehicles on public lands, was not likely to adversely affect the Cushenbury oxytheca, Cushenbury buckwheat, and triple-ribbed milk-vetch or critical habitat of the first two species. The Service (2006) concurred with your request. In our biological opinion, the Service (2006) concluded that the proposed action was not likely to jeopardize the continued existence of the desert tortoise, Parish’s daisy, Cushenbury milk-vetch, or Lane Mountain milk-vetch or result in the destruction or adverse modification of critical habitat for the first three species; at the time of that consultation, the Service had not designated critical habitat for Lane Mountain milk-vetch.

In 2016, the Service and Bureau consulted on the land use plan amendment for the Desert Renewable Energy Conservation Plan. As part of that consultation (Service 2016a), the Bureau determined and the Service concurred that the proposed land use plan amendment was not likely to adversely affect the Cushenbury oxytheca, Cushenbury milk-vetch, Cushenbury buckwheat, Parish’s daisy, Lane Mountain milk-vetch, or triple-ribbed milk-vetch. In the same consultation, the Service also concurred with the Bureau’s conclusion that the proposed action was not likely to adversely affect critical habitat of the first five species.

The biological opinion for the land use plan amendment (Service 2016a) discusses the reasons for reaching these conclusions:

As we described in more detail previously in this section, the Bureau’s proposed action (i.e., adoption of the land use plan amendment) would amend only those portions of the land use plans that address renewable energy facilities and land use allocations. The changes in land use allocations for most species and critical habitats increase the level of protection from that which these species and critical habitats currently experience under the existing land use plans. Increasing the level of protection to listed species and critical habitat is entirely beneficial; therefore, the Bureau has determined and the Service concurs that the proposed action is not likely to adversely affect most of the listed species and critical habitat areas that occur within the action area.

To clarify the relationships of these biological opinions, this biological opinion supersedes the 2006 biological opinion only for the route network. The incidental take statement in the 2006 biological opinion remains in place with regard to livestock grazing and casual use that is not associated with the route network. “Casual use” refers to individuals using routes designated as open; these non-commercial uses do not require individual authorization from the Bureau. The land use plan amendment for the Desert Renewable Energy Conservation Plan superseded the Bureau’s overall management direction. The incidental take statement in the biological opinion 3

for that land use plan amendment (Service 2016a) addressed only incidental take associated with the development of renewable energy facilities within development focus areas. The Bureau addresses all other future discretionary activities that it authorizes, funds, or undertakes in separate consultations; however, the conservation and management actions from the Desert Renewable Energy Conservation Plan apply to future activities in the California Desert Conservation Area.

In the current consultation, the Bureau and Service included Cushenbury oxytheca, Cushenbury buckwheat, and triple-ribbed milk-vetch (and critical habitat of the first two species) in the biological opinion. To conduct a conservative analysis, the Bureau based its effects analysis on modeled habitat (as determined during the planning for the Desert Renewable Energy Conservation Plan). Finally, the Bureau has upgraded its GIS capabilities since the 2006 consultation, which allows it to consider the location of routes with regard to modeled habitat in detail.

The Service (2019a) provided a draft biological opinion for the Bureau’s review on September 24, 2019. We received the Bureau’s comments on the draft biological opinion on September 26, 2019 (Bureau 2019d) and incorporated comments as appropriate. During the development of this biological opinion, the Bureau and Service discussed numerous issues to clarify information in the final supplemental environmental impact statement and errata. We also added minor activities to the proposed action, such as moving desert tortoises from harm’s way, if necessary, during the Bureau’s on-the-ground activities to maintain the route network. We memorialized these additions to the proposed action through the exchange of the draft biological opinion.

BIOLOGICAL OPINION

DESCRIPTION OF THE PROPOSED ACTION

The Bureau’s (2019a) request for formal consultation notes that the proposed action (alternative 5) includes both plan-level and implementation-level decisions as described in the final supplemental environmental impact statement (Bureau 2019b). The final supplemental environmental impact statement includes five alternatives. Alternative 1 is the “no action alternative;” we considered the information associated with this alternative to be the environmental baseline. We have summarized the proposed action in the following sections; for a more detailed description of the proposed action, please refer to Table 2.1-1 in the final supplemental environmental impact statement.

Each plan amendment includes a general proposed change to the California Desert Conservation Area Plan and one or more implementation-level decisions that provide detail on how the Bureau would implement the plan amendment. Although the plan amendments do not specify any on- the-ground changes in management direction in and of themselves, the implementation-level decisions provide the level of detail required for the Service to conduct our section 7(a)(2) analysis. 4

Plan Amendment I

The Bureau proposes to change the language in the California Desert Conservation Area Plan that limits the route network in the West Mojave Planning Area to existing routes of travel as of 1980. Through this plan amendment, the Bureau would modify the motor vehicle access element to eliminate the current “limited to existing routes” language and replace it with language to reflect that use will be “restricted to designated routes of travel.”

The implementation-level decision associated with this plan amendment is the designation of a travel and transportation route network and nine associated travel management plans. The final travel and transportation route network comprises 5,997 miles of designated off-highway vehicle open and limited routes and 230 miles of routes that are closed to off-highway vehicles but open to non-motorized or non-mechanized use (Symons 2019) .The final route network differs to a small degree from that described in the final supplemental environmental impact statement because of changes required by the John D. Dingell, Jr. Conservation, Management, and Recreation Act (Dingell Act) (Toedtli 2019).

The final supplemental environmental impact statement (abstract) notes that Alternative 1 is a continuation of current management. The proposed action (Alternative 5) includes 557 miles of routes that the Bureau did not identify in previous inventories; they are not newly created routes. Many of the newly mapped routes provide access to small homestead parcels of private lands in the area to the east of the city of Twentynine Palms. Additional newly mapped routes are spur roads to the pylons of transmission lines from the main access road.

Appendix C of the final supplemental environmental impact statement contains a glossary that defines the terms the Bureau uses in describing the various types of “ground transportation linear features.” We are incorporating the glossary by reference and have attempted to use the same terms in this biological opinion.

Plan Amendment II

The Bureau proposes to designate a framework by adopting travel management areas and associated objectives in accordance with its Travel and Transportation Management Handbook to facilitate travel management planning. As part of the proposed action, the Bureau has identified nine travel management areas as depicted in Figure 2.2-6 of the final supplemental environmental impact statement. The designation of travel management areas is a planning tool that will not affect the listed species or critical habitat in and of itself. Therefore, we will not discuss this plan amendment further in this biological opinion.

The Bureau has proposed to implement a route network that allows for destination- and touring- oriented goals and objectives. These goals and objectives do not establish the network itself; therefore, we will not specifically address them in this biological opinion but will focus our analysis on the route network proposed by the Bureau. 5

Through this plan amendment, the Bureau proposes to delineate travel management areas that meet the land use planning objectives to facilitate travel management planning. Travel management areas are optional planning tools to outline transportation issues and help delineate travel networks to address specific uses and resource concerns. The Bureau may base travel management areas on areas with unique or shared circumstances, high levels of controversy, or complex resource considerations.

The implementation-level decision associated with this plan amendment is the identification of nine travel management areas as depicted in Figure 2.2-6 of the final supplemental environmental impact statement. The identification of nine travel management areas is a planning tool that will not affect the listed species or critical habitat in and of itself. Therefore, we will not discuss this implementation-level decision further in this biological opinion.

Plan Amendment III

Through this plan amendment, the Bureau (2019b, page 2-5) proposes to update specific parameters for access and corridors for organized competitive events. This plan amendment includes two associated implementation-level decisions.

The first implementation-level decision concerns the designation of approximately 15 miles of “C” routes for competitive off-highway vehicle races (Toedtli 2019). These races would operate under special recreation permits year-round adjacent to the Spangler Hills Off-highway Vehicle Recreation Area. These “C” routes are located between the city of Ridgecrest and the Spangler Hills Off-Highway Vehicle Recreation Area and outside of areas of critical environmental concern and California Desert National Conservation Lands.

Through the second implementation-level decision, the Bureau also proposes to allow for a speed-controlled connector route between the Johnson Valley and Stoddard Valley Off-highway vehicle Recreation Areas (Toedtli 2019). The Service will focus its analysis on these two implementation level decision (i.e., the “C” routes near the Spangler Hills Off-highway Vehicle Recreation Area and the connector route). This connector route would traverse the Ord-Rodman Critical Habitat Unit. Events on this connector route would operate under special recreation permits year-round with appropriate mitigation measures to protect wildlife (Bureau 2019b, page 4-100), including a maximum speed limit of 25 miles per hour.

Plan Amendment IV

The Bureau (2019b) proposes to modify general use designations related to washes, sand dunes, and dry lakes through this plan amendment. The Bureau would add Koehn, Cuddeback, Coyote, and Chisholm Trail lakebeds to the list of designated lakebeds.

The Bureau proposes to designate Koehn Dry Lake as closed to off-highway vehicle use, except for approved routes of travel or as authorized by land use permit or special recreation permit. The final supplemental environmental impact statement (page 4-14) states that Koehn Dry Lake is not designated and that it is designated as open to off-highway vehicle use; it also notes that 6

use is relatively light. Designation of Koehn Dry Lake as closed would not increase the level of off-highway vehicle use. Additionally, desert tortoises rarely cross dry lakes and none of the listed plant species occur in this area. We will address the effects of off-highway vehicle use on designated routes elsewhere in this biological opinion; the Bureau will follow standard consultation procedures if it contemplates the issuance of land use or special recreation permits. For these reasons, we will not discuss the implementation-level decision regarding Koehn Dry Lake further in this biological opinion.

The designation of Chisholm Trail Dry Lake as off-highway vehicle closed to all types of human use will not affect the listed plant species or their critical habitat because this area is outside the range of these species. The proposed closure is not likely to adversely affect the desert tortoise because desert tortoises rarely use dry lakes; closing the dry lake to all human use would eliminate the low potential for off-highway vehicles to kill or injured a desert tortoise. The dry lake in not within critical habitat of the desert tortoise. Consequently, we will not discuss the implementation-level decision with regard to Chisholm Trail Dry Lake further in this biological opinion.

The Bureau proposes to designate Cuddeback and Coyote dry lakes as open to off-highway vehicle use. We will discuss the effects of this implementation-level decision further in this biological opinion with regard to the desert tortoise. The listed plant species do not occur near these dry lakes.

Plan Amendment V

Through this plan amendment, the Bureau proposes to change the limitations on off-highway vehicle use in the Rand Mountains-Fremont Valley Management Area, as described in the 2005 West Mojave Plan. The implementation-level decision associated with this plan amendment proposed by the Bureau is the elimination of the requirement for a permit to enter the designated network in the Rand Mountains-Fremont Valley Management Area. In place of the permit system, the Bureau proposes to manage the travel network in this area as it manages other areas of critical environmental concern for the desert tortoise.

The Rand Mountains-Fremont Valley Management Area comprises a component of the desert tortoise’s range and critical habitat within the action area. The Endangered Species Act and the implementing regulations for section 7(a)(2) at 50 CFR 402 require that we consider the effects of an action within the context of the entire listed taxon and its critical habitat. Because the Bureau’s proposed action is to manage this area in the same manner that it manages other areas of critical environmental concern established for the desert tortoise, our analysis will consider management of the travel network in the Rand Mountains-Fremont Valley Management Area within the context of the network, the listed taxon, and critical habitat. The listed plant species do not occur in this area. Therefore, we will not discuss this specific implementation-level decision further in this biological opinion. 7

Plan Amendment VI

Through this plan amendment, the Bureau proposes to change the limitation on stopping, parking, and camping adjacent to minimize impacts from the route network on a planning area- wide basis. The Bureau established the current limitations through the initial California Desert Conservation Area Plan and the 2005 plan amendments. Within areas of critical environmental concern for the desert tortoise, the Bureau currently limits stopping and parking to within 50 feet of the centerline of the route; in these areas, it also limits camping to adjacent to routes in previously disturbed areas. Outside of these areas, the Bureau limits stopping, parking, and camping to within 300 feet of the centerline of designated routes.

The Bureau’s implementation-level decision under this plan amendment is to limit stopping, parking, and camping to previously disturbed areas within 50 feet of the route centerline inside areas of critical environmental concern for the desert tortoise and California Desert National Conservation Lands. Outside of these areas, the Bureau proposes to limit stopping, parking, and camping to previously disturbed areas within 100 feet of the route centerline. The Bureau also proposes to limit stopping, parking, and camping to designated areas outside of 50- and 100-foot areas that are already disturbed.

Plan Amendment VII

The Bureau proposes to modify livestock grazing management by reallocating animal unit months and modify allotment boundaries for those allotments in desert tortoise areas of critical environmental concern. The Bureau would not change the manner in which it manages livestock grazing on active allotments in areas of critical environmental concern for the desert tortoise. It would continue to manage these allotments as described in the final environmental impact statement for the West Mojave Plan (Bureau 2005) and as modified in the land use plan amendment for the Desert Renewable Energy Conservation Plan (Bureau 2015a), and the related biological opinions (Service 2006 and 2016a). Because the Bureau’s proposed action with regard to livestock grazing has not changed since the 2006 consultation and we have previously analyzed its effects, we will not discuss this plan amendment further in this biological opinion.

Implementation of the Travel and Transportation Program

As we have mentioned previously in this section, the Bureau’s proposed plan amendments would require it to implement numerous activities on the ground to implement its travel and transportation network. Appendix G (Bureau 2019b) contains a detailed description of the manner in which the Bureau will implement the travel and transportation network and the possible minimization and mitigation measures it will employ as part of its management. We are incorporating Appendix G by reference. The following paragraphs briefly describe this section.

The Bureau (2019b, Appendix G, page G-31) will employ adaptive management to address ongoing route-specific or area-wide transportation needs and issues. Such needs and issues include monitoring of routes, efforts to identify historic properties per the National Historic Preservation Act, rehabilitation, land acquisitions and disposals, new land use authorizations, and 8

changes in vehicle types and public land-use patterns. Table G-2 (Bureau 2019b) lists “possible minimization and mitigation actions” that the Bureau may undertake to address various resource concerns, such as air quality, noise, and cultural and natural resources.

Ground disturbance that may result from any activity within areas of critical environmental concern and California Desert National Conservation Lands is subject to the disturbance caps in the land use plan amendment for the Desert Renewable Energy Conservation Plan (Bureau 2015a). If the disturbance would occur outside the prism of the current route, the Bureau will calculate the amount of disturbance and include that amount in its cumulative totals. With some exceptions (e.g., activities on previously disturbed lands, etc.), the Bureau will develop a strategy to mitigate the disturbance and a timeline for its implementation. Activities that enhance the values of areas of critical environmental concern or California Desert National Conservation Lands are exempt from the cap provisions, as described in the land use plan amendment for the Desert Renewable Energy Conservation Plan (Bureau 2015a).

During the course of this consultation, the Bureau and Service agreed that the Bureau would not need to conduct additional consultation with the Service, as described at 50 Code of Federal Regulations (CFR) 402, for the implementation activities that fall within the scope of its final supplemental environmental impact statement and this biological opinion. The Bureau may seek technical assistance from the Service at any time. If any implementation activity falls outside the scope of the final supplemental environmental impact statement and this biological opinion, the Bureau would initiate consultation, pursuant to 50 CFR 402, as appropriate.

Additionally, during the course of consultation, the Bureau and Service recognized that Bureau, contractors, and partners who are conducting on-the-ground implementation activities are likely to encounter desert tortoises occasionally. For example, desert tortoises may take shelter under parked vehicles or within work sites; in rare occasions, the Bureau may encounter occupied burrows within a restoration site. To allow implementation activities to continue without undue delay and to ensure the safety of desert tortoises, the Bureau and Service agreed that workers with sufficient training will be able to move these desert tortoises from harm’s way, if necessary. Sufficient training can include direction from biologists from the Bureau and Service. If necessary, workers will move desert tortoises no more than 300 feet from the work site and place them in shade in an area with available shelter (e.g., caliche caves, burrows, shrubs, rock shelters). Workers will avoid knowingly placing animals that they move from harm’s way near other desert tortoises.

Monitoring

In many consultations, the Federal agency is proposing to disturb a specific area of habitat over a defined time. The Federal agency and Service can then estimate the number of individuals of the listed species in that area and assess, in a reasonably direct manner, the effects of the proposed action, including the affected number of individuals of the listed species. In this case, the Bureau is not proposing to disturb a specific area of habitat over a defined time. The activities on which it is consulting are restricted to previously disturbed areas and will occur over time. However, 9

desert tortoises are mobile; they can enter routes and the previously disturbed areas on which the Bureau proposes to allow stopping, parking, and camping. For this reason, off-highway vehicles threaten desert tortoises in a less predictable manner.

For these reasons, monitoring using standard protocols is not reasonable. Therefore, the Service and Bureau have agreed that the Bureau will require all of its permittees, contractors, employees, and field crews to notify it whenever they detect a dead or injured desert tortoise. Upon receiving the notification, the Bureau and Service will discuss whether the incident resulted from casual use or from a special permit or right-of-way grant.

The Bureau will transport any injured desert tortoise to a qualified veterinarian. If the desert tortoise recovers from its injuries but is not suitable for return to the wild, the Bureau will count this individual as a mortality. Rehabilitated desert tortoises returned to the wild will not count as mortalities.

For these reasons, the Bureau and Service have agreed that the Bureau will re-initiate formal consultation if it finds four large desert tortoises that die because of casual use of its route network in a calendar year. We specified “large” desert tortoises for two reasons. First, the Service includes only desert tortoises that are 180 millimeters or larger in its calculations when assessing densities through its program of range-wide sampling. (Throughout this biological opinion, we will refer to desert tortoises that are 180 millimeters and larger as “large” desert tortoises; we refer to individuals smaller than 180 millimeters as “small” desert tortoises.) Therefore, using desert tortoises in the same size range for both monitoring take and assessing population trends is appropriate. Our second reason is that our experience with range-wide sampling is that field workers are better at detecting desert tortoises that are 180 millimeters and larger.

In an amendment to a previous biological opinion regarding the Bureau’s activities in the western Mojave Desert, the Service (2007) anticipated that eight desert tortoises were likely to die annually because of casual use of the route network within the planning area. We also anticipated the loss of five desert tortoises to livestock grazing and six through casual use related to mining. Based on our professional judgment, monitoring since that time, and discussions with the Bureau, we anticipate that maintaining this amount of mortality is reasonable. We will base our analysis in this biological opinion on the loss of eight large desert tortoises per year.

In the 2007 amendment, we considered the requirement to re-initiate on the finding of three dead desert tortoises; we did not link the re-initiation requirement to a specific cause of death. In this biological opinion, we are specifically linking the finding of four large dead desert tortoises to casual use of the route network. We increased the number to four because we anticipate that the likelihood of finding dead desert tortoises is greater now than it was in 2007. The amount of conservation activity with regard to the desert tortoise in the Western Mojave Recovery Unit has increased substantially since 2007. The Bureau and conservation organizations are routinely conducting restoration work; other crews are monitoring desert tortoises and common ravens 10

(Corvus corax). For this reason, we expect the biologists and other field workers will find more desert tortoises that have died because of casual use of the route network than in the past.

Because the Bureau would authorize some off-highway vehicle events under special use permits, it will consult with the Service separately on those actions. The Bureau and Service will include any desert tortoises killed during the conduct of an event under a special use permit under the consultation for that event. The incidental take statement in this biological opinion will account for desert tortoises killed during casual use of the route network and the Bureau’s on-the-ground activities to monitor and manage the network. The incidental take statement will also address the issue that the Bureau’s proposed action would allow some activities to take place without future authorizations (i.e., casual use of the route network and on-the-ground implementation of the route network) but would require future case-by-case evaluations of other activities (i.e., events that use the “C” routes and connector route).

The Bureau and Service will reassess, and alter if appropriate, the re-initiation threshold every 5 years using the results of the Service’s range-wide sampling program and the number of large tortoises killed in the previous 5 years. For example, if the density of desert tortoises decreases, we may reduce the re-initiation threshold accordingly.

ANALYTICAL FRAMEWORK FOR THE JEOPARDY AND ADVERSE MODIFICATION DETERMINATIONS

Jeopardy Determination

Section 7(a)(2) of the Endangered Species Act requires that Federal agencies ensure that any action they authorize, fund, or carry out is not likely to jeopardize the continued existence of listed species. “Jeopardize the continued existence of” means to engage in an action that reasonably would be expected, directly or indirectly, to reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, or distribution of that species (50 CFR § 402.02).

The jeopardy analysis in this biological opinion considers the effects of the proposed Federal action, and any cumulative effects, on the range-wide survival and recovery of the Covered Species. It relies on four components: 1) the Status of the Species, which describes the range- wide condition of the species, the factors responsible for that condition, and its survival and recovery needs; 2) the Environmental Baseline, which analyzes the condition of the Covered Species in the action area, the factors responsible for that condition, and the relationship of the action area to the survival and recovery of the Covered Species; 3) the Effects of the Action, which determines the direct and indirect impacts of the proposed Federal action and the effects of any interrelated or interdependent activities on the Covered Species; and 4) the Cumulative Effects, which evaluates the effects of future, non-Federal activities in the action area on the Covered Species.

In accordance with policy and regulation, the jeopardy determination is made by evaluating the effects of the proposed Federal action in the context of the current status of the Covered Species, 11

taking into account any cumulative effects, to determine if implementation of the proposed action is likely to reduce appreciably the likelihood of both the survival and recovery of a Covered Species in the wild by reducing the reproduction, numbers, and distribution of that species.

Adverse Modification Determination

Section 7(a)(2) of the Endangered Species Act requires that Federal agencies ensure that any action they authorize, fund, or carry out is not likely to result in the destruction or adverse modification of critical habitat. This biological opinion does not rely on the regulatory definition of "destruction or adverse modification" of critical habitat at 50 Code of Federal Regulations 402.02. Instead, we have relied on the statutory provisions of the Act to complete the following analysis with respect to critical habitat.

In accordance with policy and regulation, the adverse modification analysis in this biological opinion relies on four components: (1) the Status of Critical Habitat, which describes the range•wide condition of designated critical habitat for the desert tortoise in terms of primary constituent elements, the factors responsible for that condition, and the intended recovery function of the critical habitat overall; (2) the Environmental Baseline, which analyzes the condition of the critical habitat in the action area, the factors responsible for that condition, and the recovery role of the critical habitat in the action area; (3) the Effects of the Action, which determines the direct and indirect impacts of the proposed Federal action and the effects of any interrelated and interdependent activities on the primary constituent elements, and how that will influence the recovery role of the affected critical habitat units; and (4) Cumulative Effects, which evaluates the effects of future non-Federal activities in the action area on the primary constituent elements and how that will influence the recovery role of affected critical habitat units.

For purposes of the adverse modification determination, the effects of the proposed federal action on the critical habitat of the desert tortoise are evaluated in the context of the range-wide condition of the critical habitat, taking into account any cumulative effects, to determine if the critical habitat range-wide would remain functional (or would retain the current ability for the primary constituent elements to be functionally established in areas of currently unsuitable but capable habitat) to serve its intended recovery role for the desert tortoise.

STATUS OF THE SPECIES AND CRITICAL HABITAT

Status of the Desert Tortoise

Listing History

The Service listed the Mojave population of desert tortoise (all desert tortoises north and west of the Colorado River in Arizona, Utah, Nevada, and California) as threatened on April 2, 1990 [55 Federal Register (FR) 12178]. 12

Recovery Plan

In the revised recovery plan for the desert tortoise, the Service (2011) identified the need for “conservation areas” to protect existing desert tortoise populations and habitat. These areas include designated critical habitat, areas of critical environmental concern, the Desert National Wildlife Refuge, National Park Service lands, and other conservation areas or easements managed for desert tortoises. The revised recovery plan lists three objectives and associated criteria to achieve delisting. The first objective is to maintain self-sustaining populations of desert tortoises within each recovery unit into the future. The criterion is that the rates of population change for desert tortoises are increasing (i.e., lambda, λ > 1) over at least 25 years (i.e., a single generation), as measured by extensive, range-wide monitoring across conservation areas within each recovery unit and by direct monitoring and estimation of vital rates (recruitment, survival) from demographic study areas within each recovery unit.

The second objective addresses the distribution of desert tortoises. The goal is to maintain well- distributed populations of desert tortoises throughout each recovery unit; the criterion is that the distribution of desert tortoises throughout each conservation area increases over at least 25 years.

The final objective is to ensure that habitat within each recovery unit is protected and managed to support long-term viability of desert tortoise populations. The criterion is that the quantity of desert tortoise habitat within each conservation area be maintained with no net loss until population viability is ensured.

The revised recovery plan (Service 2011) also recommends connecting blocks of desert tortoise habitat, such as critical habitat units and other important areas, to maintain gene flow between populations. Linkages defined using least-cost path analysis (Averill-Murray et al. 2013) illustrate a minimum connection of habitat for desert tortoises between blocks of habitat and represent priority areas for conservation of population connectivity. Figure 1 illustrates that, across the range, desert tortoises in areas under the highest level of conservation and management remain subject to numerous threats, stresses, and mortality sources. 13

Figure 1. Recovery units, critical habitat units, conservation areas, and contiguous high value habitat. 14

Threats

The threats described in the listing rule and both recovery plans (Service 1994, 2011) continue to affect the species. The most apparent threats to the desert tortoise are those that result in mortality and permanent habitat loss across large areas, such as urbanization and large-scale renewable energy projects and those that fragment and degrade habitats, such as proliferation of roads and highways, off-highway vehicle activity, wildfire, and habitat invasion by non-native invasive plant species.

We remain unable to quantify how threats affect desert tortoise populations. The assessment of the original recovery plan emphasized the need for a better understanding of the implications of multiple, simultaneous threats facing desert tortoise populations and of the relative contribution of multiple threats on demographic factors (i.e., birth rate, survivorship, fecundity, and death rate; Tracy et al. 2004).

To better understand the relationship of threats to populations of desert tortoises and the most effective manner to implement recovery actions, the Service’s Desert Tortoise Recovery Office developed a spatial decision support system that models the interrelationships of threats to desert tortoises and how those threats affect population change. The spatial decision support system describes the numerous threats that desert tortoises face, explains how these threats interact to affect individual animals and habitat, and how these effects in turn bring about changes in populations. For example, we have long known that the construction of a transmission line can result in the death of desert tortoises and loss of habitat. We have also known that common ravens, known predators of desert tortoises, use transmission line pylons for nesting, roosting, and perching and that the access routes associated with transmission lines provide a vector for introduction and spread of invasive weeds and facilitate increased human access into an area. Increased human access can accelerate illegal collection and release of desert tortoises and their deliberate maiming and killing, as well as facilitate the spread of other threats associated with human presence, such as vehicle use, garbage and dumping, and invasive plants (Service 2011). Changes in the abundance of native plants, because of invasive weeds, can compromise the physiological health of desert tortoises, making them more vulnerable to drought, disease, and predation. The spatial decision support system allows us to map threats across the range of the desert tortoise and model the intensity of stresses that these multiple and combined threats place on desert tortoise populations.

The following map (Figure 2) depicts the 12 critical habitat units of the desert tortoise, linkages between conservation areas for the desert tortoise and the aggregate stress that multiple, synergistic threats place on desert tortoise populations, as modeled by the spatial decision support system. Conservation areas include designated critical habitat and other lands managed for the long-term conservation of the desert tortoise (e.g., the Desert Tortoise Natural Area, Joshua Tree National Park, and the Desert National Wildlife Refuge). 15

Figure 2. Critical habitat units, recovery units, and linkages.

Five-Year Review

Section 4(c)(2) of the Endangered Species Act requires the Service to conduct a status review of each listed species once every 5 years. The purpose of a 5-year review is to evaluate whether the species’ status has changed since listing (or since the most recent 5-year review); these reviews, at the time of their completion, provide the most up-to-date information on the range-wide status of the species. For this reason, we are appending the 5-year review of the status of the desert tortoise (Appendix A; Service 2010; can be accessed at to this biological opinion and are incorporating it by reference to provide most of the information needed for this section of the biological opinion. The following paragraphs provide a summary of the relevant information in the 5-year review.

In the 5-year review, the Service discusses the status of the desert tortoise as a single distinct population segment and provides information on the Federal Register notices that resulted in its listing and the designation of critical habitat. The Service also describes the desert tortoise’s ecology, life history, spatial distribution, abundance, habitats, and the threats that led to its listing 16

(i.e., the five-factor analysis required by section 4(a)(1) of the Endangered Species Act). In the 5- year review, the Service concluded by recommending that the status of the desert tortoise as a threatened species be maintained.

With regard to the status of the desert tortoise as a distinct population segment, the Service concluded in the 5-year review that the recovery units recognized in the original and revised recovery plans (Service 1994 and 2011, respectively) do not qualify as distinct population segments under the Service’s distinct population segment policy (61 FR 4722; February 7, 1996). We reached this conclusion because individuals of the listed taxon occupy habitat that is relatively continuously distributed, exhibit genetic differentiation that is consistent with isolation-by-distance in a continuous-distribution model of gene flow, and likely vary in behavioral and physiological characteristics across the area they occupy as a result of the transitional nature of, or environmental gradations between, the described subdivisions of the Mojave and Colorado deserts.

The Service summarizes information in the 5-year review with regard to the desert tortoise’s ecology and life history. Of key importance to assessing threats to the species and to developing and implementing a strategy for recovery is that desert tortoises are long lived, require up to 20 years to reach sexual maturity, and have low reproductive rates during a long period of reproductive potential. The number of eggs that a female desert tortoise can produce in a season is dependent on a variety of factors including environment, habitat, availability of forage and drinking water, and physiological condition. Predation seems to play an important role in clutch failure. Predation and environmental factors also affect the survival of hatchlings. The Service notes in the 5-year review that the combination of the desert tortoise’s late breeding age and a low reproductive rate challenges our ability to recover the species.

The 5-year review also notes that desert tortoises increase their reproduction in high rainfall years; more rain provides desert tortoises with more high quality food (i.e., plants that are higher in water and protein), which, in turn, allows them to lay more eggs. Conversely, the physiological stress associated with foraging on food plants with insufficient water and nitrogen may leave desert tortoises vulnerable to disease, and the reproductive rate of diseased desert tortoises is likely lower than that of healthy animals. Young desert tortoises also rely upon high- quality, low-fiber plants (e.g., native annual plants) with nutrient levels not found in the invasive weeds that have increased in abundance across its range (Oftedal et al. 2002; Tracy et al. 2004). Compromised nutrition of young desert tortoises likely represents an effective reduction in reproduction by reducing the number of animals that reach adulthood. Consequently, although we do not have quantitative data that show a direct relationship, the abundance of weedy species within the range of the desert tortoise has the potential to affect the reproduction of desert tortoises and recruitment into the adult population in a negative manner.

“Adult” desert tortoise connotes reproductive maturity. Desert tortoises may become reproductive at various sizes. We have used the term “adult” in this biological opinion to indicate reproductive status. In range-wide sampling and for pre-project surveys, the Service uses 180 millimeters as its cut-off length for counting desert tortoises, because the Styrofoam models used 17

for training are 180 millimeters in length and surveyors fail to detect desert tortoises smaller than 180 millimeters at higher rates.

The vast majority of threats to the desert tortoise or its habitat are associated with human land uses. Using captive neonate and yearling desert tortoises, Drake et al. (2015) found that individuals “eating native forbs had better body condition and immune functions, grew more, and had higher survival rates (>95%) than (desert) tortoises consuming any other diet”; health and body condition declined in individuals fed only grasses (native or non-native). Current information indicates that invasive species likely affect a large portion of the desert tortoise’s range. Furthermore, high densities of weedy species increase the likelihood of wildfires; wildfires, in turn, destroy native species and further the spread of invasive weeds.

Drake et al. (2015) compared movement patterns, home-range size, behavior, microhabitat use, reproduction, and survival for adult desert tortoises located in, and adjacent to, burned habitat in Nevada. They noted that the fires killed many desert tortoises but found that, in the first five years post-fire, individuals moved deeper into burned habitat on a seasonal basis and foraged more frequently in burned areas (corresponding with greater production of annual plants and herbaceous perennials in these areas). Production of annual plants upon which desert tortoises feed was 10 times greater in burned versus unburned areas but was dominated by non-native species (e.g., red brome [Bromus rubens]) that frequently have lower digestibility than native vegetation. During years six and seven, the movements of desert tortoises into burned areas contracted with a decline in the live cover of a perennial forage plant that rapidly colonizes burned areas. Drake et al. (2015) did not find any differences in health or survivorship for desert tortoises occupying either habitat (burned or unburned) during this study or in reproduction during the seventh year after the fire.

Since the completion of the 5-year review, the Service has issued several biological opinions that affect large areas of desert tortoise habitat because of numerous proposals to develop renewable energy within its range. These biological opinions concluded that proposed solar plants were not likely to jeopardize the continued existence of the desert tortoise primarily because they were located outside of critical habitat and areas of critical environmental concern designated by the Bureau that contain most of the land base required for the recovery of the species. The proposed actions also included numerous measures intended to protect desert tortoise during the construction of the projects, such as translocation of affected individuals. In aggregate, these projects would result in an overall loss of approximately 48,041 acres of habitat of the desert tortoise. We also predicted that the project areas supported up to 4,363 desert tortoises; we concluded that most of these individuals were small desert tortoises, that most large desert tortoises would likely be translocated from project sites, and that most mortalities would be small desert tortoises (< 180 millimeters) that were not detected during clearance surveys. To date, 660 desert tortoises have been observed during construction of solar projects (see Appendix B); most of these individuals were translocated from work areas, although some desert tortoises have been killed. The mitigation required by the Bureau and California Energy Commission (the agencies permitting some of these facilities) resulted in the acquisition of private land and funding for the implementation of various actions that are intended to promote the recovery of the desert 18

tortoise. These mitigation measures are consistent with recommendations in the recovery plans for the desert tortoise; many of the measures have been derived directly from the recovery plans and the Service supports their implementation. We expect that, based on the best available scientific information, they will result in conservation benefits to the desert tortoise; however, it is difficult to assess how desert tortoise populations will respond because of the long generation time of the species. Appendix B summarizes information regarding the solar projects that have undergone formal consultation with regard to the desert tortoise.

In August 2016, the Service (2016a) issued a biological opinion to the Bureau for a land use plan amendment under the Desert Renewable Energy Conservation Plan. The land use plan amendment addressed all aspects of the Bureau’s management of the California Desert Conservation Area; however, the Service and Bureau agreed that only those aspects related to the construction, operation, maintenance, and decommissioning of renewable energy facilities were likely to adversely affect the desert tortoise. The land use plan amendment resulted in the designation of approximately 388,000 acres of development focus areas where the Bureau would apply a streamlined review process to applications for projects that generate renewable energy; the Bureau estimated that approximately 11,290 acres of modeled desert tortoise habitat within the development focus areas would eventually be developed for renewable energy. The Bureau also adopted numerous conservation and management actions as part of the land use plan amendment to further reduce the adverse effects of renewable energy development on the desert tortoise.

The land use plan amendment also increased the amount of land that the Bureau manages for conservation in California (e.g., areas of critical environmental concern, California Desert National Conservation Lands, etc.) from 6,118,135 to 8,689,669 acres (Bureau 2015a); not all of the areas subject to increased protection are within desert tortoise habitat. The Bureau will also manage lands outside of development focus areas according to numerous conservation and management actions; these conservation and management actions are more protective of desert tortoises than direction contained in the previous land use plan. The Service (2016a) concluded that the land use plan amendment was not likely to jeopardize the continued existence of the desert tortoise and would benefit its recovery.

In addition to the biological opinions issued for solar development within the range of the desert tortoise, the Service (2012) also issued a biological opinion to the Department of the Army (Army) for the use of additional training lands at Fort Irwin. As part of this proposed action, the Army translocated approximately 650 adult desert tortoises from 18,197 acres of the southern area of Fort Irwin, which had been off-limits to training, to lands south of the base that are managed by the Bureau and the Army. The Army would also use an additional 48,629 acres that lie east of the former boundaries of Fort Irwin; much of this parcel is either too mountainous or too rocky and low in elevation to support numerous desert tortoises. As part of the proposed action, the Army also acquired approximately 100,000 acres of non-federal land within the Superior-Cronese Critical Habitat Unit for management for conservation of desert tortoises. It also purchased the base property of three cattle allotments; the Bureau subsequently re-allotted 19

the forage on those allotments to wildlife. The Army also funded several other activities aimed at conserving desert tortoises in the current planning area.

The Service also issued a biological opinion to the Department of the Navy (Navy) that considered the effects of the expansion of the Marine Corps Air Ground Combat Center at Twentynine Palms (Service 2017a). We concluded that the Navy’s proposed action, the use of approximately 167,982 acres of public and private land for training, was not likely to jeopardize the continued existence of the desert tortoise. Most of the expansion area lies within the Johnson Valley Off-highway Vehicle Recreation Area. As part of this proposed action, the Navy translocated 997 large desert tortoises from the expansion area to 4 recipient sites to the north and east of the expansion area (Henen 2019). The Lucerne-Ord and Siberia sites are entirely within Bureau-managed lands, and the Rodman-Sunshine Peak North and Cleghorn sites overlap Bureau-managed lands and lands managed by the Navy. The Lucerne-Ord site lies within the Ord-Rodman Area of Critical Environmental Concern. The Navy translocated desert tortoises from the Johnson Valley Off-highway Vehicle Recreation Area into populations that were below the Service’s established minimum viable density, to attempt to augment these populations and make them more viable in the long-term.

The Service also issued a biological opinion to the Navy that considered the effects of the expansion of the Naval Air Weapons Station at China Lake (Service 2019b). We concluded that the Navy’s proposed action, the use of approximately 2,777 acres of the 26,509-acre Cuddeback Range expansion area, was not likely to jeopardize the continued existence of the desert tortoise. The Cuddeback Range lies within the Superior-Cronese Critical Habitat Unit. However, all of the disturbance would occur in a previously disturbed area that the U.S. Air Force historically used as a target zone. The Navy will include the entire Cuddeback Range in its Integrated Natural Resource Management Plan and construct a perimeter fence around the range to prevent trespass by the public. These actions will provide conservation benefits for plants, fish, and wildlife within the area, including the desert tortoise. Because the Navy will not disturb most of the area, it did not translocate any desert tortoises as part of this action.

The incremental effect of the larger actions (i.e., solar development, the expansions of Fort Irwin and the Marine Corps Air Ground Combat Center) on the desert tortoise is unlikely to be positive, despite the numerous conservation measures that have been (or will be) implemented as part of the actions. The acquisition of private lands as mitigation for most of these actions increases the level of protection afforded these lands; however, these acquisitions do not create new habitat and Federal, State, and privately managed lands remain subject to most of the threats and stresses we discussed previously in this section. Land managers have been implementing measures to manage these threats and we expect, based on the best available scientific information, that such measures provide conservation benefits to the desert tortoise. We have been unable, to date, to determine whether desert tortoise populations have benefited from the measures. This is partly because of the low reproductive capacity of the desert tortoise. Therefore, the conversion of habitat into areas that are unsuitable for this species continues the trend of constricting the desert tortoise into a smaller portion of its range. 20

As the Service notes in the 5-year review (Service 2010), “[t]he threats identified in the original listing rule continue to affect the [desert tortoise] today, with invasive species, wildfire, and renewable energy development coming to the forefront as important factors in habitat loss and conversion. The vast majority of threats to the desert tortoise or its habitat are associated with human land uses.”

Climate change is likely to affect the prospects for the long-term conservation of the desert tortoise. For example, predictions for climate change within the range of the desert tortoise suggest more frequent and/or prolonged droughts with an increase of the annual mean temperature by 3.5 to 4.0 degrees Celsius. The greatest increases will likely occur in summer (June-July-August mean increase of as much as 5 degrees Celsius [Christensen et al. 2007]). Precipitation will likely decrease by 5 to 15 percent annually in the region; with winter precipitation decreasing by up to 20 percent and summer precipitation increasing by up to 5 percent. Because germination of the desert tortoise’s food plants is highly dependent on cool- season rains, increasing temperatures and decreasing winter precipitation could reduce the forage base. Although drought occurs routinely in the Mojave Desert, extended periods of drought have the potential to affect desert tortoises and their habitats through physiological effects to individuals (i.e., stress) and limited forage availability. To place the consequences of long-term drought in perspective, Longshore et al. (2003) demonstrated that even short-term drought could result in elevated levels of mortality of desert tortoises. Therefore, long-term drought is likely to have even greater effects, particularly given that the current fragmented nature of desert tortoise habitat (e.g., urban and agricultural development, highways, freeways, military training areas, etc.) will make recolonization of extirpated areas difficult, if not impossible.

Core Criteria for the Jeopardy Determination

When determining whether a proposed action is likely to jeopardize the continued existence of a species, we are required to consider whether the action would “reasonably be expected, directly or indirectly, to reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by reducing the reproduction, numbers, or distribution of that species” (50 CFR 402.02). Although the Service does not explicitly address these metrics in the 5-year review, we have used the information in that document and more recent information to summarize the status of the desert tortoise with respect to its reproduction, numbers, and distribution.

Reproduction

In the 5-year review, the Service notes that desert tortoises increase their reproduction in high rainfall years; more rain provides desert tortoises with more high quality food (i.e., plants that are higher in water and protein), which, in turn, allows them to lay more eggs. Conversely, the physiological stress associated with foraging on food plants with insufficient water and nitrogen may leave desert tortoises vulnerable to disease (Oftedal et al. 2002), and the reproductive rate of diseased desert tortoises is likely lower than that of healthy animals. Young desert tortoises also rely upon high-quality, low-fiber plants (e.g., native annual plants) with nutrient levels not found 21

in the invasive weeds that have increased in abundance across its range (Oftedal et al. 2002; Tracy et al. 2004). Compromised nutrition of young desert tortoises likely represents an effective reduction in reproduction by reducing the number of animals that reaches adulthood; see previous information from Drake et al. (2015). Consequently, although we do not have quantitative data that show a direct relationship, the abundance of weedy species within the range of the desert tortoise has the potential to affect the reproduction of desert tortoises and recruitment into the adult population in a negative manner.

Various human activities have introduced numerous species of non-native invasive plants into the California desert. Routes that humans use to travel through the desert (paved and unpaved roads, railroads, motorcycle trails, etc.) serve as pathways for new species to enter habitat of the desert tortoise and for species that currently occur there to spread. Other disturbances of the desert substrate also provide invasive species with entry points into the desert. Figure 3 depicts the potential for these species to invade habitat of the desert tortoise. The abundance and distribution of invasive weeds may compromise, at least to some degree in localized areas across its range, the reproductive capacity of the desert tortoise; the continued increase in human access across the desert likely continues to facilitate the spread of weeds and further affect the reproductive capacity of the species.

Figure 3. Potential for exotic plant invasion in desert tortoise habitat. 22

Numbers

In the 5-year review, the Service discusses various means by which researchers have attempted to determine the abundance of desert tortoises and the strengths and weaknesses of those methods. Due to differences in area covered and especially to the non-representative nature of earlier sample sites, data gathered by the Service’s current range-wide monitoring program cannot be reliably compared to information gathered through other means at this time.

Data from small-scale study plots (e.g., one square mile) established as early as 1976 and surveyed primarily through the mid-1990s indicate that localized population declines occurred at many sites across the desert tortoise’s range, especially in the western Mojave Desert. Spatial analyses of more widespread surveys also found evidence of relatively high mortality in some parts of the range (Tracy et al. 2004). Although we cannot extrapolate population densities from the local study plots to provide an estimate of the number of desert tortoises on a range-wide basis, historical densities in some parts of the desert exceeded 38 per square kilometer (Tracy et al. 2004). The Service (2010) concluded that “appreciable declines at the local level in many areas, which coupled with other survey results, suggest that declines may have occurred more broadly.”

The range-wide monitoring that the Service initiated in 2001 is the first comprehensive attempt to determine the densities of desert tortoises in conservation areas across their range. Allison and McLuckie (2018) used annual density estimates obtained from this sampling effort to evaluate range- wide trends in the density of desert tortoises over time. (All references to the density of desert tortoises within each sampling stratum are averages. Some local areas within each sampling stratum support higher densities and some lower; desert tortoises do not occur in uniform densities across large areas.) This analysis indicates that densities in the Northeastern Mojave Recovery Unit have increased since 2004, with the increase apparently resulting from increased survival of adults and sub-adults moving into the adult size class. The analysis also indicates that the populations in the other four recovery units are declining; Table 1 depicts the estimated abundance of desert tortoises within the recovery units and the change in abundance. Surveys did not include the steepest slopes in these desert tortoise conservation areas; however, the model developed by Nussear et al. (2009) generally rates steep slopes as less likely to support desert tortoises. Table 1: Change in desert tortoise abundance in recovery units (Allison and McLuckie 2018)1.

Modeled 2004 2014 Change in Recovery Units Habitat (km2) Abundance Abundance Abundance Western Mojave 23,139 131,540 64,871 -66,668 Colorado Desert 18,024 103,675 66,097 -37,578 Northeastern Mojave 10,664 12,610 46,701 +34,091 Eastern Mojave 16,061 75,342 24,664 -50,679 Upper Virgin River 613 13,226 10,010 -3,216 Total: 68,501 336,393 212,343 -124,050 1 Allison and McLuckie (2018) used modeled habitat within the entire Western Mojave Recovery Unit for this estimate. In other discussions in this biological opinion, we used information from Service (2015b), which used only the area of sampled habitat to estimate the number of desert tortoises in the recovery unit. 23

In the previous summary of the results of range-wide sampling (Service 2015b), we extrapolated the densities obtained within conservation areas (e.g., desert wildlife management area, Desert Tortoise Research Natural Area, Joshua Tree National Park) to all modeled habitat of the desert tortoise. This extrapolation may have exaggerated the number of desert tortoises because we applied the values for areas where densities are generally highest (i.e., the conservation areas) to areas where desert tortoises exist in very low densities (e.g., the Antelope Valley). We are also aware of a few areas where the density of desert tortoises outside of conservation areas is higher than inside.

To further examine the status of desert tortoise populations over time, we compared the densities of desert tortoises in the Western Mojave Recovery Unit between 2004 and 2014 (see Service 2015b). In 2004, desert tortoise conservation areas surveyed in the Western Mojave Recovery Unit supported an average density of approximately 5.7 adults per square kilometer. In contrast, surveys in the same areas in 2014 indicated that densities had decreased to 2.8 adults per square kilometer. This decline in densities is consistent with decreases in density of populations in all recovery units over the same time, with the exception of the Northeastern Mojave Recovery Unit. In fact, historical survey data from numerous plots in the Western Mojave Recovery Unit during the late 1970s and early 1980s suggest that adult desert tortoise densities ranged from 19 to 58 per square kilometer (Tracy et al. 2004).

To further assess the status of the desert tortoise, the Desert Tortoise Recovery Office (Service 2015b) used multi-year trends from the best-fitting model describing log-transformed density of adult animals per square kilometer. In 2014, 3 of the 5 recovery units supported densities below 3.9 adult animals per square kilometer [Western Mojave (2.8), Eastern Mojave (1.5), and Colorado Desert (3.7); see table 10 in Service 2015b], which is the minimum density recommended to avoid extinction in the 1994 recovery plan. The Northeastern Mojave Recovery Unit supported 4.4 adult desert tortoises per square kilometer and the Upper Virgin River Recovery Unit, which is by far the smallest recovery unit, supported 15.3 adults per square kilometer.

The Service (2015b) evaluated changes in size distribution of desert tortoises since 2001. In the Western Mojave and Colorado Desert recovery units, the relative number of juveniles to adults indicates that juvenile numbers are declining faster than adults. In the Eastern Mojave, the number of juvenile desert tortoises is also declining, but not as rapidly as the number of adults. In the Upper Virgin River Recovery Unit, trends in juvenile numbers are similar to those of adults; in the Northeastern Mojave Recovery Unit, the number of juveniles is increasing, but not as rapidly as are adult numbers in that recovery unit. Juvenile numbers, like adult densities, are responding in a directional way, with increasing, stable, or decreasing trends, depending on the recovery unit.

In this context, we consider “juvenile” desert tortoises to be animals smaller than 180 millimeters in length. The Service does not include juveniles detected during range-wide sampling in density estimations because they are more difficult to detect and surveyors frequently do not observe 24

them during sampling. However, this systematic range-wide sampling provides us with an opportunity to compare the proportion of juveniles to adults observed between years.

Distribution

Prior to 1994, desert tortoises were extirpated from large areas within their distributional limits by urban and agricultural development (e.g., the cities of Barstow and Lancaster, California; Las Vegas, Nevada; and St. George, Utah; agricultural areas south of Edwards Air Force Base and east of Barstow), military training (e.g., Fort Irwin, Leach Lake Gunnery Range), and off-road vehicle use (e.g., portions of off-road recreation areas managed by the Bureau and unauthorized use in areas such as east of California City, California).

Urban development around Las Vegas has likely been the largest contributor to habitat loss throughout the range since 1994. The Army has translocated desert tortoises from the 18,197- acre southern expansion area at Fort Irwin (Service 2012). The development of large solar facilities has also reduced the amount of habitat available to desert tortoises. No solar facilities have been developed within areas of critical environmental concern that the Bureau has designated for the desert tortoise in California, although such projects have occurred in areas that the Service considers important linkages between conservation areas (e.g., Silver State South Project in Nevada).

In recognition of the absence of specific and recent information on the location of habitable areas within the Mojave Desert, especially at the outer edges, Nussear et al. (2009) developed a quantitative, spatial habitat model for the desert tortoise north and west of the Colorado River (Figure 4). The model incorporates environmental variables such as precipitation, geology, vegetation, and slope and is based on occurrence data of desert tortoises from sources spanning more than 80 years, including data from the 2001 to 2008 range-wide monitoring surveys. The model predicts the relative potential for desert tortoises to be present in any given location, given the combination of habitat variables at that location in relation to areas of known occupancy throughout the range. Calculations of the amount of desert tortoise habitat in the 5-year review (Service 2010) and in this biological opinion use of a threshold of 0.5 or greater predicted value for potential desert tortoise habitat. The model does not account for anthropogenic effects to habitat and represents the potential for occupancy by desert tortoises absent these effects. 25

Figure 4. Modeled habitat of the desert tortoise (Nussear et al. 2009).

26

Table 2 depicts acreages of habitat (as modeled by Nussear et al. 2009, using only areas with a probability of occupancy by desert tortoises greater than 0.5 as potential habitat) within the recovery units of the desert tortoise and of impervious surfaces as of 2006 (Fry et al. 2011); calculations are by Darst (2014). Impervious surfaces include paved and developed areas and other disturbed areas that have zero probability of supporting desert tortoises. All units are in acres.

Table 2: Modeled habitat of the desert tortoise.

Impervious Surfaces Remaining Recovery Units Modeled Habitat (percentage) Modeled Habitat Western Mojave 7,585,312 1,989,843 (26) 5,595,469 Colorado Desert 4,950,225 510,862 (10) 4,439,363 Northeastern Mojave 3,012,293 386,182 (13) 2,626,111 Eastern Mojave 4,763,123 825,274 (17) 3,937,849 Upper Virgin River 231,460 84,404 (36) 147,056 Total: 20,542,413 3,796,565 (18) 16,745,848

The Service (2010) concluded in its 5-year review that the distribution of the desert tortoise has not changed substantially since the publication of the original recovery plan in 1994 in terms of the overall extent of its range. Since 2010, we again conclude that the species’ distribution has not changed substantially in terms of the overall extent of its range, although desert tortoises have been removed from several thousand acres because of solar development, military activities, and other project development.

Status of Critical Habitat of the Desert Tortoise

The Service designated critical habitat for the desert tortoise in portions of California, Nevada, Arizona, and Utah in a final rule published February 8, 1994 (59 FR 5820). The Service designates critical habitat to identify the key biological and physical needs of the species and key areas for recovery and to focus conservation actions on those areas. Within the geographical area occupied by the species at the time of listing, critical habitat is composed of specific geographic areas that contain the physical or biological features essential to the species’ conservation and that may require special management considerations or protection. These features, which include space, food, water, nutrition, cover, shelter, reproductive sites, and special habitats, are called the physical and biological features of critical habitat. The specific physical and biological features of critical habitat of the desert tortoise are: sufficient space to support viable populations within each of the six recovery units and to provide for movement, dispersal, and gene flow; sufficient quality and quantity of forage species and the proper soil conditions to provide for the growth of these species; suitable substrates for burrowing, nesting, and overwintering; burrows, caliche caves, and other shelter sites; sufficient vegetation for shelter from temperature extremes and predators; and habitat protected from disturbance and human-caused mortality.

Critical habitat of the desert tortoise would not be able to fulfill its conservation role without each of the physical and biological features being functional. For example, critical habitat would 27

not function properly if a sufficient amount of forage species were present but human-caused mortality was excessive. A second example is an area with sufficient space to support viable populations within each of the six recovery units and to provide for movement, dispersal, and gene flow would not function properly without adequate forage species.

The final rule for designation of critical habitat did not explicitly ascribe specific conservation roles or functions to the various critical habitat units. Rather, it refers to the strategy of establishing recovery units and “desert wildlife management areas” recommended by the recovery plan for the desert tortoise, which had been published as a draft at the time of the designation of critical habitat, to capture the “biotic and abiotic variability found in desert tortoise habitat” (59 FR 5823). Specifically, we designated the critical habitat units to follow the direction provided by the draft recovery plan for the establishment of desert wildlife management areas. The critical habitat units in aggregate are intended to protect the variability that occurs across the large range of the desert tortoise; the loss of any specific unit may compromise the ability of critical habitat to serve its intended function and conservation role.

Despite the fact that desert tortoises do not necessarily need to move between critical habitat units to complete their life histories, both the original and revised recovery plans discuss the importance of these critical habitat units and connectivity between them for the recovery of the species. Although it determined that linkages between critical habitat units did not meet the definition of critical habitat, the Service (1994) recommended the identification of buffer zones and linkages for smaller desert tortoise conservation areas to aid in overall recovery efforts.

We did not designate the Desert Tortoise Natural Area or Joshua Tree National Park in California or the Desert National Wildlife Refuge in Nevada as critical habitat because they are “primarily managed as natural ecosystems” (59 FR 5825) and provide adequate protection to desert tortoises. Since the designation of critical habitat, Congress increased the size of Joshua Tree National Park and created the Mojave National Preserve. A portion of the expanded boundary of Joshua Tree National Park lies within critical habitat of the desert tortoise; portions of other critical habitat units lie within the boundaries of the Mojave National Preserve.

Congress also increased the size of the Johnson Valley Off-highway Vehicle Recreation Area through the passage of the Dingell Act in 2019. This act included 3,471 acres of the Ord-Rodman Critical Habitat Unit in the Johnson Valley Off-highway Vehicle Recreation Area, which represents approximately 1.37 percent of the 253,200-acre critical habitat unit.

Within each critical habitat unit, both natural and anthropogenic factors affect the function of the physical and biological features of critical habitat. As an example of a natural factor, in some specific areas within the boundaries of critical habitat, such as within and adjacent to dry lakes, some of the physical and biological features are naturally absent because the substrate is extremely salty; desert tortoises do not normally reside in such areas. Comparing the acreage of desert tortoise habitat as depicted by Nussear et al.’s (2009) model to the gross acreage of the critical habitat units demonstrates quantitatively that the entire area within the boundaries of critical habitat likely does not support the physical and biological features. In Table 3, the 28

acreage for modeled habitat is for the area in which the probability that desert tortoises are present is greater than 0.5. The acreages of modeled habitat do not include loss of habitat due to human-caused impacts. The difference between gross acreage and modeled habitat is 653,214 acres; that is, approximately 10 percent of the gross acreage of the designated critical habitat is unlikely to support the features of habitat that are conducive to the presence of desert tortoises.

Table 3: Acreage of gross area and modeled habitat within critical habitat units for the desert tortoise. We have not adjusted the acreage for the Ord-Rodman Critical Habitat Unit in response to the Dingell Act.

Critical Habitat Unit Gross Area (acres) Modeled Habitat (acres) Superior-Cronese 766,900 724,967 Fremont-Kramer 518,000 501,095 Ord-Rodman 253,200 184,155 Pinto Mountain 171,700 144,056 Piute-Eldorado 970,600 930,008 Ivanpah Valley 632,400 510,711 Chuckwalla 1,020,600 809,319 Chemehuevi 937,400 914,505 Gold Butte-Pakoon 488,300 418,189 Mormon Mesa 427,900 407,041 Beaver Dam Slope 204,600 202,499 Upper Virgin River 54,600 46,441 Total: 6,446,200 5,792,986

Human activities can have obvious or more subtle effects on the physical and biological features of critical habitat. The grading of an area and subsequent construction of a building removes physical and biological features; this action has an obvious effect on critical habitat. The revised recovery plan identifies human activities such as urbanization and the proliferation of roads and highways as threats to the desert tortoise and its habitat; these threats are examples of activities that have a clear effect on the physical and biological features of critical habitat.

Condition of the Physical and Biological Features of Critical Habitat

We have included the following paragraphs from the revised recovery plan for the desert tortoise (Service 2011) to demonstrate that other anthropogenic factors affect the physical and biological features of critical habitat in more subtle ways. All references are in the revised recovery plan (i.e., in Service 2011); we have omitted some information from the revised recovery plan where the level of detail was unnecessary for the current discussion.

Surface disturbance from [off-highway vehicle] activity can cause erosion and large amounts of dust to be discharged into the air. Recent studies on surface dust impacts on gas exchanges in Mojave Desert shrubs showed that plants encrusted by dust have reduced photosynthesis and decreased water-use efficiency, which may decrease primary production during seasons when photosynthesis occurs (Sharifi et al. 1997). Sharifi et al. (1997) also 29

showed reduction in maximum leaf conductance, transpiration, and water-use efficiency due to dust. Leaf and stem temperatures were also shown to be higher in plants with leaf-surface dust. These effects may also impact desert annuals, an important food source for [desert] tortoises.

[Off-highway vehicle] activity can also disturb fragile cyanobacterial-lichen soil crusts, a dominant source of nitrogen in desert ecosystems (Belnap 1996). Belnap (1996) showed that anthropogenic surface disturbances may have serious implications for nitrogen budgets in cold desert ecosystems, and this may also hold true for the hot deserts that [desert] tortoises occupy. Soil crusts also appear to be an important source of water for plants, as crusts were shown to have 53 percent greater volumetric water content than bare soils during the late fall when winter annuals are becoming established (DeFalco et al. 2001). DeFalco et al. (2001) found that non-native plant species comprised greater shoot biomass on crusted soils than native species, which demonstrates their ability to exploit available nutrient and water resources. Once the soil crusts are disturbed, non-native plants may colonize, become established, and out-compete native perennial and annual plant species (D’Antonio and Vitousek 1992; DeFalco et al. 2001). Invasion of non-native plants can affect the quality and quantity of plant foods available to desert tortoises. Increased presence of invasive plants can also contribute to increased fire frequency.

Proliferation of invasive plants is increasing in the Mojave and Sonoran deserts and is recognized as a substantial threat to desert tortoise habitat. Many species of non-native plants from Europe and Asia have become common to abundant in some areas, particularly where disturbance has occurred and is ongoing. As non-native plant species become established, native perennial and annual plant species may decrease, diminish, or die out (D’Antonio and Vitousek 1992). Land managers and field scientists identified 116 species of non-native plants in the Mojave and Colorado deserts (Brooks and Esque 2002).

Increased levels of atmospheric pollution and nitrogen deposition related to increased human presence and combustion of fossil fuels can cause increased levels of soil nitrogen, which in turn may result in significant changes in plant communities (Aber et al. 1989). Many of the non-native annual plant taxa in the Mojave region evolved in more fertile Mediterranean regions and benefit from increased levels of soil nitrogen, which gives them a competitive edge over native annuals. Studies at three sites within the central, southern, and western Mojave Desert indicated that increased levels of soil nitrogen can increase the dominance of non-native annual plants and promote the invasion of new species in desert regions. Furthermore, increased dominance by non-native annuals may decrease the diversity of native annual plants, and increased biomass of non-native annual grasses may increase fire frequency (Brooks 2003).

This summary from the revised recovery plan (Service 2011) demonstrates how the effects of human activities on habitat of the desert tortoise are interconnected. In general, surface disturbance causes increased rates of erosion and generation of dust. Increased erosion alters additional habitat outside of the area directly affected by altering the nature of the substrate, 30

removing shrubs, and possibly destroying burrows and other shelter sites. Increased dust affects photosynthesis in the plants that provide cover and forage to desert tortoises. Disturbed substrates and increased atmospheric nitrogen enhance the likelihood of invasive species establishment and competition with native species; the proliferation of weedy species increases the risk of large-scale fires, which further move habitat conditions away from those that are favorable to desert tortoises.

The following paragraphs generally describe how the threats described in the revised recovery plan affect the physical and biological features of critical habitat of the desert tortoise.

Sufficient space to support viable populations within each of the six recovery units and to provide for movement, dispersal, and gene flow.

Urban and agricultural development, concentrated use by off-road vehicles, and other activities such as development of transmission lines and pipelines completely remove habitat. Although we are aware of local areas within the boundaries of critical habitat that have been heavily disturbed, we do not know of any areas that have been disturbed to the intensity and extent that the function of this physical and biological feature has been compromised. To date, the largest single loss of critical habitat is the use of 18,197 acres of additional training land in the southern portion of Fort Irwin.

The widening of existing freeways likely caused the second largest loss of critical habitat. Despite these losses of critical habitat, which occur in a linear manner, the critical habitat units continue to support sufficient space to support viable populations within each of the six recovery units.

In some cases, major roads likely disrupt the movement, dispersal, and gene flow of desert tortoises. State Route 58 and Highway 395 in the Fremont-Kramer Critical Habitat Unit, Fort Irwin Road in the Superior-Cronese Critical Habitat Unit, and Interstate 10 in the Chuckwalla Critical Habitat Unit are examples of large and heavily travelled roads that likely disrupt movement, dispersal, and gene flow. Roads that have been fenced and provided with underpasses may alleviate this fragmentation to some degree; however, such facilities have not been in place for sufficient time to determine whether they will eliminate fragmentation.

The threats of invasive plant species described in the revised recovery plan generally do not result in the removal of this physical and biological feature because they do not convert habitat into impervious surfaces, as would urban development.

Sufficient quality and quantity of forage species and the proper soil conditions to provide for the growth of these species.

This physical and biological features address the ability of critical habitat to provide adequate nutrition to desert tortoises. As described in the revised recovery plan and 5-year review, grazing, historical fire, invasive plants, altered hydrology, drought, wildfire potential, fugitive dust, and climate change/temperature extremes contribute to the stress of “nutritional compromise.” Paved and unpaved roads through critical habitat of the desert tortoise provide 31

avenues by which invasive native species disperse; these legal routes also provide the means by which unauthorized use occurs over large areas of critical habitat. Nitrogen deposition from atmospheric pollution likely occurs throughout all the critical habitat units and exacerbates the effects of the disturbance of substrates. Because paved and unpaved roads are so widespread through critical habitat, this threat has adversely affected the value of critical habitat for conservation of the desert tortoise throughout its range, to some degree. See the Status of the Desert Tortoise section of this biological opinion for a map that depicts the routes by which invasive weeds have access to critical habitat; the routes shown on the map are a subset of the actual number of routes that cross critical habitat of the desert tortoise.

Suitable substrates for burrowing, nesting, and overwintering.

Surface disturbance, motor vehicles traveling off route, use of off-highway vehicle management areas, off-highway vehicle events, unpaved roads, grazing, historical fire, wildfire potential, altered hydrology, and climate change leading to shifts in habitat composition and location, storms, and flooding can alter substrates to the extent that they are no longer suitable for burrowing, nesting, and overwintering. Erosion caused by these activities can alter washes to the extent that desert tortoise burrows placed along the edge of a wash, which is a preferred location for burrows, could be destroyed. We expect that the area within critical habitat that is affected by off-road vehicle use to the extent that substrates are no longer suitable is relatively small in relation to the area that desert tortoises have available for burrowing, nesting, and overwintering; consequently, off-road vehicle use has not had a substantial effect on this physical and biological feature.

Most livestock allotments have been eliminated from within the boundaries of critical habitat. Of those that remain, livestock would compact substrates to the extent that they would become unsuitable for burrowing, nesting, and overwintering only in areas of concentrated use, such as around watering areas and corrals. Because livestock grazing occurs over a relatively small portion of critical habitat and the substrates in most areas within livestock allotments would not be substantially affected, suitable substrates for burrowing, nesting, and overwintering remain throughout most of the critical habitat units.

Burrows, caliche caves, and other shelter sites.

Human-caused effects to burrows, caliche caves, and other shelter sites likely occur at a similar rate as effects to substrates for burrowing, nesting, and overwintering for the same general reasons. Consequently, sufficient burrows, caliche caves, and other shelter sites remain in the critical habitat units.

Sufficient vegetation for shelter from temperature extremes and predators.

In general, sufficient vegetation for shelter from temperature extremes and predators remains throughout critical habitat. In areas where large fires have occurred in critical habitat, many of the shrubs that provide shelter from temperature extremes and predators have been destroyed; in such areas, cover sites may be a limiting factor. The proliferation of invasive plants poses a 32

threat to shrub cover throughout critical habitat as the potential for larger and more frequent wildfires increases.

In 2005, wildfires in Nevada, Utah, and Arizona burned extensive areas of critical habitat (Service 2010). Although different agencies report slightly different acreages, Table 4 provides an indication of the scale of the fires.

Table 4: Summary of total burned area within desert tortoise critical habitat.

Total Area Critical Habitat Unit Percent of the Critical Habitat Unit Burned Burned (acres) Beaver Dam Slope 53,528 26 Gold-Butte Pakoon 65,339 13 Mormon Mesa 12,952 3 Upper Virgin River 10,557 19

The revised recovery plan notes that the fires caused statistically significant losses of perennial plant cover, although patches of unburned shrubs remained. The percentages of burned habitat do not mean that the fire removed all habitat value for desert tortoises. Drake et al. (2015) noted that the production of annual plants was 10 times greater in burned areas compared to unburned areas; however, non-native plants, such as red brome (Bromus madritensis subsp. rubens), dominated the burned areas. Desert tortoises continued to use the dead branches of shrubs, such as creosote (Larrea tridentata) and burro bush (Ambrosia dumosa). Their use of burrows was similar in burned and unburned areas (Drake et al. 2015). We cannot quantify precisely the extent to which these fires disrupted the function and value of the critical habitat, given the patchiness with which the physical and biological features of critical habitat are distributed across the critical habitat units and the varying intensity of the wildfires. The work by Drake et al. (2015) demonstrates that the physical and biological features within burned areas retain at least some of their value for the conservation of desert tortoises but conclude that “burned habitat may take years to recover sufficiently to fully support (desert) tortoise populations.”

Habitat protected from disturbance and human-caused mortality.

In general, the Federal agencies that manage lands within the boundaries of critical habitat have adopted land management plans that include implementation of some or all of the recommendations contained in the original recovery plan for the desert tortoise (see pages 70 to 72 of Service 2010). To at least some degree, the adoption of these plans has resulted in the implementation of management actions that are likely to reduce the disturbance and human- caused mortality of desert tortoises. For example, these plans resulted in the designation of open routes of travel and the closure (and, in some cases, physical closure) of unauthorized routes. Numerous livestock allotments have been relinquished by the permittees and cattle no longer graze these allotments. Because of actions on the part of various agencies, many miles of highways and other paved roads have been fenced to prevent desert tortoises from wandering into traffic and being killed. The Service and other agencies of the Desert Managers Group in 33

California are implementing a plan to remove common ravens that prey on desert tortoises and to undertake other actions that would reduce subsidies (i.e., food, water, sites for nesting, roosting, and perching, etc.) that facilitate their abundance in the California Desert (Service 2008a). The Bureau’s (2015a) land use plan amendment for the Desert Renewable Energy Conservation Plan increased the amount of land under protective status and adopted conservation and management actions that furthered the Bureau’s goals for these areas.

Despite the implementation of these actions, disturbance and human-caused mortality continue to occur in many areas of critical habitat (which overlap the Bureau’s areas of critical environmental concern for the most part and are the management units for which most data are collected) to the extent that the value of critical habitat for the conservation of the desert tortoise is, to some degree, adversely affected. For example, many highways and other paved roads in California remain unfenced. Hughson and Darby (2013) noted that as many as 10 desert tortoises are reported killed annually on paved roads within Mojave National Preserve. Because carcasses on roads are quickly removed by scavengers or destroyed by other vehicles, we expect that more desert tortoises are killed on roads than are reported.

Unauthorized off-road vehicle use continues to disturb habitat and result in loss of vegetation within the boundaries of critical habitat; although we have not documented the death of desert tortoises as a direct result of this activity, it likely occurs. Additionally, the habitat disturbance caused by this unauthorized activity exacerbates the spread of invasive plants, which displace native plants that are important forage for the desert tortoise, thereby increasing the physiological stress faced by desert tortoises.

Finally, in California, the Bureau will not allow the development of renewable energy facilities on public lands within the boundaries of areas of critical environmental concern and California Desert National Conservation Lands (which largely correspond to the boundaries of critical habitat). Counties have not specifically restricted the development of renewable energy facilities on private lands within the boundaries of areas of critical environmental concern. However, the checkerboard pattern of land ownership would likely necessitate that the Bureau consider issuance of a right-of-way for such a facility, which likely decreases the potential for such proposals in the future.

Summary of the Status of Critical Habitat of the Desert Tortoise

As noted in the 5-year review and revised recovery plan for the desert tortoise (Service 2010, 2011), critical habitat of the desert tortoise is subject to landscape-level impacts in addition to the site-specific effects of individual human activities. On the landscape level, atmospheric pollution is increasing the level of nitrogen in desert substrates; the increased nitrogen exacerbates the spread of invasive plants, which outcompete the native plants necessary for desert tortoises to survive. As invasive plants increase in abundance, the threat of large wildfires increases; wildfires have the potential to convert the shrubland-native annual plant communities upon which desert tortoises depend to a community with fewer shrubs and more invasive plants. In such a community, shelter and forage would be more difficult for desert tortoises to find. 34

Invasive plants have already compromised the value of critical habitat for the conservation of the desert tortoise to some degree with regard to the second physical and biological feature (i.e., sufficient quality and quantity of forage species and the proper soil conditions to provide for the growth of these species). These effects likely extend to the entirety of critical habitat, given the numerous routes by which invasive plants can access critical habitat and the large spatial extent that is subject to nitrogen from atmospheric pollution.

Land managers have undertaken actions to improve the status of critical habitat. For example, as part of its efforts to offset the effects of the use of additional training maneuver lands at Fort Irwin (Service 2004), the Department of the Army acquired the private interests in the Harper Lake and Cronese Lakes allotments, which are located within critical habitat in the Western Mojave Recovery Unit; as a result, cattle have been removed from these allotments. Livestock have been removed from numerous other allotments through various means throughout the range of the desert tortoise. The retirement of allotments assists in the recovery of the species by eliminating disturbance to the physical and biological features of critical habitat by cattle and range improvements.

The value of critical habitat has been adversely affected to some degree with regard to the last physical and biological feature (i.e., habitat protected from disturbance and human-caused mortality) as a result of the wide variety of human activities that continues to occur within its boundaries. These effects result from the implementation of discrete human activities and are thus more site-specific in nature.

Although human activities have affected the remaining physical and biological features to some degree, these impacts have not, to date, appreciably diminished the value of the critical habitat units for the conservation of the desert tortoise. We have reached this conclusion primarily because the effects are localized and thus do not affect the value of large areas of critical habitat for the conservation of the desert tortoise.

ENVIRONMENTAL BASELINE

Regulations implementing the Act (50 CFR 402.02) define the environmental baseline as the past and present impacts of all Federal, State, or private actions and other human activities in the action area, the anticipated impacts of all proposed Federal projects in the action area that have already undergone formal or early section 7 consultation, and the impact of State and private actions which are contemporaneous with the consultation in progress.

Action Area

The “action area” refers to “all areas to be affected directly or indirectly by the Federal action and not merely the immediate area involved in the action” (50 CFR 402.02). The Federal action we are considering in this biological opinion is the proposed amendment of the California Desert Conservation Area Plan for the West Mojave Route Network Project. The action area for this biological opinion consists of approximately 3.1 million acres of public lands managed by the 35

Bureau within the planning area, as described in the final supplemental environmental impact statement that are intermixed or immediately adjacent non-federal lands, as described below.

In some portions of the planning area, lands managed by the Bureau occur in a checkerboard pattern with land owned by private entities and the State of California. We have generally considered the action area to include non-federal lands that are intermixed with or immediately adjacent to public lands; we have included lands that are immediately adjacent or intermingled in the action area because the Bureau’s management direction can profoundly affect such areas. For example, a vehicle traveling on an open route in the Superior Valley must cross both public and non-federal lands; it could not use only non-federal or public lands.

We considered large blocks of non-federal land that are not intermixed with public lands to be outside the action area. Because of the size and location, the Bureau’s management of public lands does not affect these large blocks of non-federal land. For example, we considered the intermingled public and non-federal lands in the area where the Fremont-Kramer and Superior- Cronese critical habitat units for the desert tortoise meet as being within the action area. However, we do not consider the large blocks of non-federal lands to the east of California City or to the west of the Cady Mountains and between Interstates 15 and 40 to be part of the action area. Figure 5 depicts the action area. 36

Figure 5. Map of the action area. The light gray line represents the Bureau’s planning area. The action area in our analysis comprises the area within the green lines plus all Bureau lands within the planning area that are outside the green line. Key: Tan - Bureau of Land Management; light green - Forest Service; violet – Department of Defense; white – private; orange – wilderness; dark tan - off-highway vehicle recreation areas; blue 0 State of California; purple - National Park Service. 37

Current Transportation System

The Bureau (2019b, Appendix C) defines the roads, primitive roads, and trails that it maintains as its transportation system. The following paragraphs describe the current status of the transportation system in the action area.

The Bureau (2019b) identified the current primitive route network within the action area through a compilation of inventory efforts in 1985 and 1987, 2001 and 2002, and 2012 and 2013. The Dingell Act required the Bureau to adjust its designations with regard to the current primitive route network because of the change in land use allocations.

The current inventory consists of 14,346 miles of linear disturbances outside of off-highway vehicle recreation areas on lands managed by the Bureau. The definitions of the following terms are from Appendix C of the final supplemental environmental impact statement. “Open routes” are those where “access by motorized vehicles is allowed.” “Limited routes” are available for use with “specific conditions or specific classes of users to which the route is available.” Transportation linear disturbances are “[m]an-made linear features that are not part of the [Bureau]’s Transportation System. Linear disturbances may include engineered (planned) as well as unplanned single- and two-track linear features. Even if previously authorized, these features are considered unauthorized, and suitable for removal and rehabilitation.” Table 5 depicts mileages of the current transportation system in the planning area.

Table 5. Mileage of linear disturbances in the current transportation. All units are in miles.

Transportation OHV Open and Linear Non- Limited Routes Disturbance mechanized Subtotals Within conservation areas for the 2,060.6 2,577.5 4,638.1 desert tortoise Outside of conservation areas for the 3,379.2 6,299.3 9678.5 desert tortoise Unknown 27.6 27.6 Subtotals 5, 439.8 8,876.8 27.6 14,344.31 1 All mileages are from Toedtli (2019) and include changes prompted by the Dingell Act. Slight differences between the totals shown here and in Toedtli (2019) are likely the result of rounding.

The Bureau (Toedtli 2019, Table 2.1-2) also estimated the area currently covered by inventoried linear disturbances and previously disturbed areas adjacent to open and limited routes. Table 6 depicts these areas; the Bureau estimates that approximately 1 percent of the area adjacent to open and limited routes is disturbed. The Bureau estimated all acreages based on the average width of a route of 12 feet. 38

Table 6. Habitat disturbance associated with the current transportation system. All units are in acres.

Area of Area Available for 1 Percent OHV Open Stopping, Parking, Estimated and Limited and Camping Disturbance Routes Within conservation areas for the desert 3,008.0 24,738.4 247.4 tortoise1 Outside of conservation areas for the desert 17,730.0 145,812.9 1,458.1 tortoise1 Totals2 20,738 170,551.3 1,705.5 1 Calculated from acreages in Toedtli (2019).

We noted previously that we are considering any lands not managed by the Bureau that are intermingled or adjacent to Bureau-managed lands to be part of the action area. This portion of the action area includes approximately 3,435.5 miles of routes on non-Bureau lands that are accessible only via Bureau-managed lands (Hoffmann 2019).

All mileages in this paragraph are from Tables 2.1-2 and 2.2-6 of the errata provided by the Bureau (Toedtli 2019). The current inventory consists of 14,346 total miles of off-highway vehicle or primitive routes (i.e., linear disturbances) outside of off-highway vehicle recreation areas on lands managed by the Bureau. Of this total, 5,439.8 miles are currently available to off- highway vehicle use as open or limited. “Open routes” are those where “access by motorized vehicles is allowed” (Bureau 2019b, Appendix C); approximately 4,793.4 miles of open routes currently cross Bureau lands. “Limited routes” are available for use with “specific conditions or specific classes of users to which the route is available” (Bureau 2019b, Appendix C). Approximately 646.4 miles of limited routes are currently available for use.

The current inventory also includes 27.6 miles of non-mechanized routes and 8,876.8 miles of transportation linear disturbances (Toedtli 2019). In Appendix C, the Bureau (2019b) describes transportation linear disturbances as “[m]an-made linear features that are not part of the [Bureau]’s Transportation System. Linear disturbances may include engineered (planned) as well as unplanned single- and two-track linear features. Even if previously authorized, these features are considered unauthorized, and suitable for removal and rehabilitation.” The Bureau (2019c, Table 2.1-2) estimated that, at the current time, inventoried linear disturbances cover approximately 20,738 acres of the 3.1-million acres of Bureau land in the action area; the Bureau based its acreage calculation on an average width of 12 feet for linear disturbances. Based on an estimate that 1 percent of the area available for stopping, parking, and camping is disturbed, the Bureau (Toedtli 2019) also estimated that approximately 1,705.5 acres of its lands are currently disturbed because of these activities. 39

The following table (Table 7) depicts the mileage of routes that are available to off-highway vehicles on open and limited bases and of transportation linear disturbances, and the acreage available for stopping, parking, and camping, within and outside of desert tortoise conservation areas. We calculated these numbers from the Bureau (Toedtli 2019, Table 4.4-30) by combining the values of all the areas of critical environmental concern and subtracting that total from the values in Table 2.1-2 of the errata.

Table 7. Miles of route designations and area of disturbance within and outside of desert tortoise conservation areas.

Miles OHV Open and Transportation Stopping, parking, Limited (miles) Linear Disturbance and camping (acres) (miles) Within conservation 1,534.5 2,577.5 24,738.4 areas Outside of 3,905.3 6,299.3 145,812.9 conservation areas

We noted earlier that we are considering any lands not managed by the Bureau that are intermingled or adjacent to Bureau-managed lands to be part of the action area. This portion of the action area includes approximately 3,435.5 miles of routes on non-Bureau lands that are accessible only via Bureau-managed lands and approximately 186.1 miles of routes on non- Bureau lands that are accessible via private lands.

Previous Section 7 Consultations within the Action Area

The biological opinions for the Bureau’s previous land use plan amendments are the most pertinent consultations regarding the desert tortoise that we have conducted within the action area. We have discussed those biological opinions in the Consultation History section of this biological opinion. The land use plan amendments on which the Service and Bureau have consulted have generally resulted in management direction aimed at implementing the recommendations of the recovery plans for the desert tortoise. For example, the first plan amendment resulted in the establishment of desert wildlife management areas, as recommended by the Service’s 1994 recovery plan (Bureau 2005). That plan amendment also established a disturbance cap of 1 percent on public lands within desert wildlife management areas; the Bureau also required project applicants to offset the effects of their activities through acquisition of private lands or funding of other actions, such as restoration of habitat, that supports recovery of the desert tortoise.

The land use plan amendment for the Desert Renewable Energy Conservation Plan (Bureau 2015a) replaced the desert wildlife management areas with areas of critical environmental concern (to align with the language of the Bureau’s planning guidelines) and established California Desert National Conservation Lands on additional areas. The Bureau reduced the disturbance cap to as low as 0.1 percent in some areas, set limits as to the number of desert 40

tortoises that an applicant-driven activity could disturb in any single project, and continued the program to offset the effects of applicant-driven activities.

The Bureau and Service have consulted on numerous applicant-driven activities. These activities generally fall into two categories. Off-highway vehicle events, both touring and racing, limited to open routes are a frequent type of activity. Many of these events occur on public lands outside of desert tortoise conservation areas. To date, we are not aware of any desert tortoises that have died because of these events.

The other type of activity generally results in the loss or disturbance of small amounts of habitat. These activities frequently involve small mines and the maintenance of pipelines. Most of these activities involve the use of open or limited routes to access the work areas. For example, between October 2017 and October 2018, the Bureau and Service consulted on 15 activities in the action area (Bureau 2018). Five were for off-highway vehicle events, four involved the repair of pipelines, three involved mining, and the rest covered other types of activities. In total, the Bureau estimated that these activities would disturb approximately 400 acres; most of that disturbance is associated with the repair of existing pipelines.

The Bureau has consulted on two renewable energy facilities on its lands in the planning area. One, a solar facility, has not been constructed. The Alta East Wind Project is located to the northwest of the town of Mojave. Neither project is located within an area of critical environmental concern for the desert tortoise. Desert tortoises occur in low numbers within the solar project’s boundaries. The operators of the wind project routinely see a few desert tortoises within its boundaries; they believe these are the same individuals, based on their locations (Nelson 2019). To date, we are aware of a single 3-inch- long desert tortoise that has died on a public road that traverses the project area (Davis 2019).

Status of the Desert Tortoise in the Action Area

Most of the action area is located within the Western Mojave Recovery Unit. A small portion of the southeast corner of the action area lies within in the Colorado Desert Recovery Unit. However, because it comprises such a minor portion of the overall action area, we have not summarized information for that recovery unit in this discussion.

Range-wide sampling allows us to estimate the number of desert tortoises in the conservation areas. We cannot estimate the total number of desert tortoises in the action area because we do not conduct range-wide sampling in portions of the recovery units that are outside of conservation areas. Generally, we expect that desert tortoises occur at lower densities outside of conservation areas, although we are aware of a few instances of higher densities. Overall, sampling has indicated that the number of desert tortoises has declined within the action area since 2004 (Service 2015b).

Table 7 (modified from Service 2015b) summarizes the results of range-wide sampling for the Western Mojave Recovery Unit. Because only a small portion of the Pinto Mountains Critical Habitat Unit overlaps the action area, we have not provided a summary for the broader Colorado 41

Desert Recovery Unit in which it lies. The table describes the change in abundance within these areas between 2004 and 2014 based on a multi-year trend analysis.

Table 7. Summary of range-wide sampling for the Western Mojave Recovery Unit and the critical habitat units within the action area.

Surveyed Recovery Unit/Critical 2014 Change in Area 2004 Abundance 2014 Abundance Habitat Unit Density Abundance (km2) Western Mojave 6,294 2.8 35,777 17,644 -18,133 Recovery Unit Fremont-Kramer Critical 2,347 2.6 12,251 6,196 -6,055 Habitat Unit Superior-Cronese 3,094 2.4 19,216 7,398 -11,818 Critical Habitat Unit Ord-Rodman Critical 852 3.6 7,036 3,064 -3,972 Habitat Unit Pinto Mountains Critical 508 2.4 3,126 1,241 -1,885 Habitat Unit Sampling has continued in conservation areas within all of the recovery units since 2014, but the Service has not completed additional multi-year trend analysis. Data from these more recent sampling efforts (up to 2017) indicate that annually estimated desert tortoise densities in the critical habitat units within the action area have been variable since 2014 (see Table 8, from Service 2015b, 2016b, 2018, and 2019c).

Table 8: Estimated desert tortoise densities from 2014 to 2018 for the critical habitat units within the action area.

Estimated Density (per Critical Habitat Unit Year km2) 2014 4.7 Fremont-Kramer 2015 4.5 2017 4.1 2014 2.5 2015 2.6 Superior-Cronese 2016 3.6 2017 1.7 2014 3.5 Ord-Rodman 2017 3.2/3.91 2018 2.5/3.41 2016 2.1 Pinto Mountains 2017 2.3 1 Prior to the 2017 range-wide sampling in the Ord-Rodman Critical Habitat Unit, the U.S. Marine Corps translocated desert tortoises from an expansion area at Marine Corps Air Ground Combat Center to a recipient site within the critical habitat unit. The Service estimated densities using both resident (i.e., non-translocated) and translocated desert tortoises that were located during sampling. The density of residents is the first number for the years 2017 and 2018; the second number is the density of residents plus translocated desert tortoises for these years. 42

Within the action area, desert tortoises are generally more abundant within the conservation areas and occur at low densities outside these areas. For example, the California Department of Transportation conducted surveys near the town of Olancha in southern Inyo County, which is outside of a conservation area and at the edge of the desert tortoise’s range. Biologists did not detect any desert tortoises during protocol surveys although other workers found three (Service 2014).

Within conservation areas, some areas (e.g., higher elevations and dry lakes) do not support desert tortoises. Even within apparently suitable habitat in conservation areas, desert tortoises occur in a patchy distribution. That is, few individuals occur in some areas of apparently suitable habitat; in other areas, they are locally abundant. Consequently, although data from range-wide sampling indicate that desert tortoises are declining in numbers, the distribution of suitable habitat and the patchy distribution of desert tortoises within these areas influence density estimates as derived through range-wide sampling.

Status of Critical Habitat of the Desert Tortoise in the Action Area

The conditions of the physical and biological features of desert tortoise critical habitat within the action area are generally similar to those we described in the Status of the Critical Habitat section of this biological opinion. Therefore, we will not repeat that discussion here.

Table 9 summarizes the mileage of routes in the existing inventory and the estimate of area used for stopping, parking, and camping in each critical habitat unit; all data are from the Bureau (Toedtli 2019, Table 4.4-19). The estimated acreage for stopping, parking, and camping does not include any areas along the transportation linear disturbances.

Table 9. Estimated mileage of the existing routes and acreage of stopping, parking, and camping in each critical habitat unit. The acreage for stopping, parking, and camping represents the Bureau estimate of the amount of previously disturbed habitat adjacent to open and limited routes.

Transportation Open/Limited Linear Stopping, Parking, and Critical Habitat Unit Routes (miles) Disturbances Camping (acres) (miles) Fremont-Kramer 897.5 1,396.8 135.9 Superior-Cronese 831.9 764.5 111.1 Ord-Rodman 316.6 487.7 42.3 Pinto Mountain 142.7 66.3 17.6. Total 2,188.7 2,715.3 306.9

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EFFECTS OF THE ACTION

Effects of the action refer to the direct and indirect effects of an action on the species or critical habitat, together with the effects of other activities that are interrelated and interdependent with that action that will be added to the environmental baseline. Indirect effects are those that are caused by the proposed action and are later in time, but are still reasonably certain to occur.

Methodology

In this section of the biological opinion, we will first generally consider how the Bureau’s proposed action may affect the desert tortoise and its critical habitat. We will then consider the effects of the Bureau’s implementation-level decisions. Finally, in the Conclusion section, we will integrate this general analysis with the best available information regarding the reproduction, number, and distribution of desert tortoises in the action area, to determine whether the proposed action is likely to jeopardize the continued existence of the species, as described in Analytical Framework section of the biological opinion. We will then repeat this process to assess how the proposed action affects the value of critical habitat for the conservation of the species to determine whether it is likely to result in the destruction or adverse modification of critical habitat.

Effects on the Desert Tortoise

General Discussion of the Effects of Off-Highway Vehicle Use on the Desert Tortoise

The final supplemental environmental impact statement (Bureau 2019b, section 4.4.2.2) summarizes the general effects of off-highway vehicle use on desert tortoises. Off-highway vehicles and routes can:

1. Have adverse effects to individuals due to vehicle strikes, and reduce the occurrence of desert tortoises near routes;

2. Occupy land area that would be otherwise occupied by desert tortoises;

3. Introduce and spread invasive non-native plants;

4. Change fire cycles because of increasing prevalence of invasive annual grasses;

5. Attract subsidized predators, such as common ravens, and allow dogs to have access to sensitive areas;

6. Allow access for illegal dumping, vandalism, collection of desert tortoises, abandonment of captive desert tortoises, and off-highway vehicle use of unauthorized areas;

7. Create edge effects due to water runoff that attract desert tortoises to routes; and

8. Cause population fragmentation and reduced patch size. 44

We consider this list to include those effects that are reasonably certain to occur and will base our analysis on these effects. We will evaluate how these potential effects may affect desert tortoises in relation to the proposed Plan Amendments.

We acknowledge that hikers and equestrians will also use at least some of the routes in the action area. These uses would generally have the same effect as off-highway vehicles, albeit to a lesser degree; for example, hikers may step on small desert tortoises but they generally do not travel as far and as quickly as vehicles. Consequently, we will focus our discussion on off-highway vehicle use with the assumption that any effects of hiking and equestrian use would comprise a minor component of the overall effect of the proposed action.

Plan Amendment I

The proposed action with regard to this plan amendment and its implementation-level decisions comprises the designation of 5,997 miles of off-highway vehicle open and limited routes and 230 of off-highway vehicle closed routes that are closed to off-highway vehicles but open only to non-motorized and or non-mechanized use.

Von Seckendorff and Marlow (2002) and Nafus et al. (2013) demonstrated that paved roads decrease the density of desert tortoises in adjacent habitat. We have less information available with regard to unpaved roads. Von Seckendorff and Marlow (2002) concluded that “unpaved utility access roads … [with] even lower traffic levels may have a significant detectable impact.” Possibly conversely, Grandmaison et al. (2010) found that desert tortoises tended to be closer than expected to unpaved routes and routes with low traffic volume; Lovich and Daniels (2000) documented the same trend with desert tortoise burrows.

Logically, frequently used unpaved routes that allow for higher speeds pose a greater threat to desert tortoises than less frequently used primitive routes. The density of desert tortoises and the terrain through which the route passes also factor into the level of threat.

Our general conclusion, based on the best available information and our professional judgment, is that routes, in and of themselves, do not pose an appreciable threat to desert tortoises or alter their distribution. An important exception to that general statement is that heavily maintained routes can develop berms that prevent desert tortoises from exiting; predators, extreme temperatures, collection, and vandalism can then kill these animals.

Desert tortoises that are present on routes may be struck and injured or killed by moving vehicles (Forman and Alexander 1998; Forman et al. 2003). Numerous variables factor into whether any given vehicle is likely to collide with a desert tortoise. These factors include the density of desert tortoises in an area, whether desert tortoises are active or not and present on the route, the speed of the vehicle, visibility, and the attention of the driver. For example, an attentive driver is likely to see a large desert tortoise on a smooth route when traveling at a low speed; conversely, small desert tortoises on a route with numerous rocks and ruts are difficult to detect at any speed. Desert tortoises that are sheltering beneath parked vehicles may also be crushed when the vehicles begin to move. 45

Limited routes pose the same types of adverse effects as open routes, but because of special restrictions and lower use levels, we anticipate the magnitude of risk to desert tortoises is lower than for open routes. In addition, the Bureau has designated fewer miles of limited routes than open routes, which should also result in a lower magnitude of risk when compared to open routes.

The Bureau’s proposed action would not result in the construction of new routes. The Bureau has proposed to designate as open some portions of existing routes that it had not previously considered open. Therefore, the proposed action would not decrease the area that desert tortoises currently occupy. Reclamation, restoration, and rehabilitation of transportation linear disturbances would increase, to some degree, the area available for desert tortoises to occupy.

Vehicles operating on designated routes may introduce and disperse invasive non-native plants to new areas of the desert. Invasive non-native plants can out-compete native species that desert tortoises depend on for food. Oftedal et al. (2002) demonstrated that invasive non-native plants may adversely affect the physiological health of desert tortoises because they do not contain the same types and levels of nutrients as native plants; desert tortoises that are undergoing nutritional stress may be more susceptible to diseases, drought, and predation. In a study using captive individuals, Drake et al. (2015) found that invasive grasses negatively affect the health and survival of young desert tortoises; effects to the health and survival of young desert tortoises would likely reduce the reproductive capacity of the population latter.

We do not expect the proposed action to increase the probability of introducing and spreading invasive non-native plants in the route network. Although the Bureau is proposing to allow use of approximately additional 557 miles of routes, all newly designated open and limited routes will occur with existing linear features. The Bureau (2019, page 4-4) does not anticipate that the change in the size of the route network will cause an increase in the miles traveled per year; consequently, we do not expect additional use that would increase the potential for the introduction of non-native plants. Additionally, approximately 307 miles of the total increase are limited routes; because these routes experience less use than open routes, we expect they are less likely to serve as conduits for non-native plants. The reclamation, restoration, or rehabilitation of transportation linear disturbances is likely to reduce the abundance of non-native plants within existing routes over time.

Wildfires have not been historically common in the Mojave Desert (Brooks and Matchett 2006). However, over recent decades, the frequency and size of fires have increased, largely due to highly flammable invasive annual grasses that can proliferate and provide increased fuel loads (Brooks et al. 2013). Besides the immediate adverse effect of fire killing desert tortoises (Esque et al. 2003), native scrub communities in the California desert have not generally evolved or adapted to withstand effects from fire, and are vulnerable to its effects (Abella 2010). The Bureau’s reclamation, restoration, or rehabilitation of transportation linear disturbances would likely decrease the area where wildfires are likely to start. A reduction in the spatial area where invasive and non-native plants are common would reduce the likelihood of fires. 46

Human access to desert tortoise habitat via the route network increases the amount of subsidies such as food litter and water that can attract subsidized predators. Common ravens have been proliferating due to human subsidies; common ravens are efficient predators of small desert tortoises. Visitors also bring dogs, which can attack and kill desert tortoises. The reclamation, restoration, or rehabilitation of transportation linear disturbances is likely to reduce the degree of encroachment and the magnitude of resulting effects over time.

Legal access can lead to unauthorized activities, such as illegal dumping, vandalism, collection of desert tortoises, unauthorized off-highway vehicle use, abandonment of captive tortoises, and the likelihood of wildfires. Illegal dumping can provide additional subsidies for predators. If unauthorized routes develop, all of the adverse effects we discussed in the previous paragraphs may occur. Unauthorized vehicle use off designated routes may also result in desert tortoises being struck by moving vehicles, crushed if vehicles drive over burrows that are occupied by desert tortoises, and crushed if sheltering beneath parked vehicles. The reclamation, restoration, or rehabilitation of transportation linear disturbances is likely to reduce the degree of encroachment and the magnitude of such effects over time.

Edge effects due to water runoff and collection on roads can attract desert tortoises to places where they are more likely to be struck. Invasive non-native plants may also be able to more efficiently establish with additional water resources. The proposed action would not increase edge effects because the Bureau is not creating new routes. The reclamation, restoration, or rehabilitation of transportation linear disturbances is likely to reduce the area in which edge effects can occur over time.

Roads can fragment and isolate populations (Anderson 2002; Forman et al. 2003, Andrews et al. 2005, Shepard et al. 2008), reduce adjacent densities (Forman and Alexander 1998, Forman and Deblinger 2000, Eigenbrod et al. 2009, Shanley and Pyare 2011, Peaden et al. 2015), and reduce home range size due to proximity to routes (Peaden et al. 2017). Maintaining population-level connectivity to enable gene flow is a high recovery priority. In Gray et al. (2019), intermediate distance from even minor roads and the density of desert washes were strong indicators of habitat quality that facilitates movement of desert tortoises.

Paved roads can fragment and isolate populations (Anderson 2002; Forman et al. 2003, Andrews et al. 2005, Shepard et al. 2008), reduce adjacent densities (Forman and Alexander 1998, Forman and Deblinger 2000, Eigenbrod et al. 2009, Shanley and Pyare 2011, Peaden et al. 2015), and reduce home range size due to proximity to routes (Peaden et al. 2017). Less research is available on the effects of unpaved roads with regard to the fragmentation and isolation of populations. One means of evaluating whether an activity is fragmenting and isolating populations is to determine the effect on gene flow.

Latch et al. (2011) evaluated 859 desert tortoises at 16 microsatellite loci in relation to geographic location, sex, elevation, slope, and soil type, and spatial relationship to potential anthropogenic barriers south of Fort Irwin. They found two genetically differentiated sub- populations within the area bounded roughly by Interstate 15 to the south and Fort Irwin to the 47

north. The researchers determined that slope, a paved road, and one unpaved route influenced gene flow.

Fort Irwin Road and the Manix Trail influenced gene flow. Fort Irwin Road is paved and is used by large numbers of vehicles, traveling at high speeds. The road was built long ago but heavy use recommenced when Fort Irwin resumed training in the 1970s. In 2002 or 2003, the County of San Bernardino and U.S. Army installed fencing to keep desert tortoises off the road because of the high incidence of mortalities. Manix Trail lies to the east of Fort Irwin Road. It is unpaved and wider than most (if not all) routes in the action area. The Army maintains it and uses it to move troop rotations to and from the base. Troops using the trail are supposed to be alert for desert tortoises and avoid them. The public also uses the trail.

Latch et al. (2011) detected that “[d]esert tortoise pairs from the same side of a road exhibited significantly less genetic differentiation than [desert] tortoise pairs from opposite sides” both Manix Trail and Fort Irwin Road. They note that, given the long generation time for desert tortoises, these slight genetic differences happened relatively quickly, perhaps within “dozens” of years ago. The authors also note “gene flow sufficient to maintain a low level of differentiation among subpopulations could be much less than one migrant per year or even one migrant every few decades in this species.”

Latch et al. (2011) also tested pairs of desert tortoises on either side of the Boulder Corridor, a large utility corridor that ran through their study area. This corridor contains five transmission lines, a gas line, several parallel access roads for the utilities, and numerous spur roads. They did not detect a significant difference between desert tortoises across this corridor.

This information indicates that an unpaved route can influence gene flow. Manix Trail likely has different effects on desert tortoises than other routes in the action area because of its size. The potential exists that some combination of its size, level of use, and maintenance causes it to exert different effects on desert tortoises that the Boulder Corridor. If the Boulder Corridor does not influence gene flow, we expect that most unpaved routes in the action area would not.

The intermittent use of the Boulder Corridor (and other routes in the action area) may be an important factor in influencing gene flow (and therefore fragmenting and isolating populations). Before the County of San Bernardino and Army installed desert tortoise exclusion fencing on Fort Irwin Road, desert tortoises likely could not cross it because of the high volume of fast vehicles at least 5 days a week. (With the fencing, few, if any desert tortoises, cross that road now.) Conversely, the Boulder Corridor likely undergoes its greatest vehicle load 2 days per week, when weekend recreational use is high. In short, off-highway vehicle use of unpaved routes may exert an important component of its adverse effects on desert tortoises (i.e., direct contact with people and vehicles) intermittently. The remainder of the week, during periods of lower use, desert tortoises can cross routes with reduced risk.

Neither the Bureau nor the Service have definitive information on what size of a route network would have such minimal effects on the desert tortoise that its overall conservation would not be affected. Obviously, fewer routes present fewer opportunities for vehicles to kill desert tortoises. 48

The extent to which changes to access in a route network would affect desert tortoises is difficult to measure because of the slow reproductive rate of the species and other factors such as disease, drought, and predation, which may also affect the number of individuals in a given area.

Plan Amendment III

The proposed action with regard to this plan amendment and its implementation-level decisions comprises the designation of “C” routes located adjacent to the Spangler Hills Off-highway Vehicle Recreation Area between the city of Ridgecrest and the recreation area and of a route connector linking the Johnson Valley and Stoddard Valley Off-Highway Vehicle Recreation Areas.

The designated “C” routes and the route connector would be within the existing route network; therefore, they would have the same general effects as we have previously discussed. The Bureau will limit speeds during events on the route connector to a maximum of 25 miles per hour.

The competitive events that would occur on “C” routes would require issuance of special recreation permits; the Bureau will consult with the Service on these events, as appropriate.. The Bureau will identify and implement appropriate avoidance and mitigation measures as needed through those consultations. The approximately 15 miles of “C” routes are located outside of any desert tortoise conservation area, in the Rademacher Hills between the city of Ridgecrest and the Spangler Off-highway Vehicle Recreation area; desert tortoises occur in low densities in this area. Consequently, we anticipate that this designation is likely to have a minor effect on the conservation of desert tortoises.

Plan Amendment IV

The proposed action with regard to this plan amendment and its implementation-level decisions comprises the designation of Cuddeback and Coyote dry lakes as open to off-highway vehicle use.

Dry lakes are largely devoid of vegetation and do not provide suitable habitat for desert tortoises. However, desert tortoises may infrequently enter or cross dry lakes; off-highway vehicles using the dry lakes at the same time may kill or injure these desert tortoises. We expect that such events are likely to occur rarely and do not consider this portion of the proposed action to pose a measurable risk to the conservation of desert tortoises.

Plan Amendment VI

The proposed action with regard to this plan amendment and its implementation-level decisions comprises the limitation of stopping, parking, and camping to previously disturbed areas within 50 feet of the route centerline inside areas of critical environmental concern for the desert tortoise and California Desert National Conservation Lands. Outside of these areas, the Bureau proposes to limit stopping and parking to previously disturbed areas within 100 feet of the route 49

centerline. The Bureau also proposes to designate special stopping, parking, and camping areas in previously disturbed areas outside of the 50- and 100-foot limits.

This implementation-level decision would reduce the amount of area that is available for stopping, parking, and camping compared to the current situation and would limit all parking, stopping, and camping to previously disturbed areas. Within these areas, desert tortoises may enter and be struck by vehicles. Because vehicles would generally be traveling at lower speeds than on routes and because previously disturbed areas are generally cleared of vegetation, we expect that vehicle operators would have better opportunities to see animals and be able to avoid colliding with them. Stopped and parked vehicles also pose a risk to desert tortoises because desert tortoises sometimes seek shelter beneath them and can be crushed when a vehicle starts to move. Although off-highway vehicle use of previously disturbed areas has the potential to adversely affect desert tortoises, this implementation-level decision will reduce the likelihood of off-highway vehicles striking desert tortoises.

When visitors use stopping, parking, and camping areas, they often bring food and water and leave behind litter. These subsidies attract predators of desert tortoises. Visitors may also bring dogs to these areas that can attack and kill desert tortoises.

Because the Bureau will limit stopping, parking, and camping to previously disturbed areas, the remaining effects on desert tortoises would be the same as we discussed previously. We will not repeat those discussions here.

Implementation of the Travel and Transportation Program

The Bureau will use adaptive management to implement the travel and transportation program. Acquisition and disposal of lands, changing uses, and changing technology will require that the Bureau continually re-evaluate the travel and transportation network; see the “Maintaining the Transportation Network” section of Appendix G (Bureau 2019b). When monitoring and re- evaluation indicate that use of the travel and transportation network or other changing circumstances is affecting the desert tortoise, the Bureau will employ the appropriate minimization and mitigation actions for the desert tortoise that are listed in Table G-2 (Appendix G in Bureau 2019b).

We do not know the future specific issues that the Bureau would need to address as part of the management of the travel and transportation network. However, during implementation, we expect that these issues would involve minor and localized effects to the desert tortoise that are generally similar to those that we have discussed previously in this section (e.g., vehicles using open and limited routes, minor amounts of ground disturbance to implement corrective measures). If implementation of the minimization and mitigation actions would result in ground disturbance (and therefore disturbance of the desert tortoise), the Bureau will apply the appropriate conservation and management actions from its land use plan. The Bureau has used such measures, including the conservation and management actions from the land use plan amendment (Bureau 2015a), on activities in the past; because of the implementation of these measures, activities have killed or injured few desert tortoises. Appropriate measures include, but 50

are not limited to, the use of authorized biologists or other monitors to protect desert tortoises during activities (including moving them from harm’s way), exclusion fencing, seasonal restrictions, worker education programs, and management of trash. We anticipate that moving desert tortoises from harm's way is not likely to cause elevated levels of stress. The Bureau will ensure that workers who move desert tortoises are trained to do so or are being directed by experienced Bureau or Service biologists. Because the Bureau will only move desert tortoises up to a maximum of 300 feet, we anticipate that individuals that are moved from harm's way will likely remain within their home ranges. Consequently, the Bureau’s implementation of the travel and transportation program is unlikely to affect the desert tortoise in a measurable manner.

Overall Effects on the Desert Tortoise

We will now consider the overall effects of the Bureau’s proposed action on the desert tortoise. We have considered the amount of exposure to the adverse effect of routes that the desert tortoise is likely to receive under the proposed action in relation to its reproduction, numbers, distribution, and recovery. An important aspect to our analysis is examining where designated routes and transportation linear disturbances would occur in relation to not only the action area as a whole, but also to desert tortoise conservation areas.

The proposed action includes 557 miles of routes that the Bureau did not identify in previous inventories; these are not newly created routes. Many of these routes are outside of conservation areas for the desert tortoise; for example, many newly mapped routes provide access to small homestead parcels of private lands in the area to the east of the city of Twentynine Palms. Additional newly mapped routes are spur roads to the pylons of transmission lines from the main access road; spur roads occur both within and outside of conservation areas for the desert tortoise.

Table 10. Comparison of the mileage of the route network within and outside of conservation areas for the desert tortoise1.

Miles of OHV Open And Limited Routes Current Situation Proposed Action Source Total 5,439.8 5,997.2 Table 2.3-2 Within areas of critical Table 4.4-30; sum of environmental concern 1,534.5 2,055.7 ACECs Outside areas of critical Subtract “within” from environmental concern 3,905.3 3,941.5 “total” 1Data from Toedtli (2019) and include changes prompted by the Dingell Act

Compared to the current transportation system that we described in the Environmental Baseline section of the biological opinion, the Bureau’s proposed action would increase the mileage of open and limited routes in the transportation network by approximately 557 miles. However, this increase in the mileage of open and limited routes would not cause the creation of new disturbances in the Bureau’s inventory because these routes already exist on the ground; these routes have been used by off-highway vehicles in the past. Desert tortoises are likely to be killed 51

or injured by vehicles using these routes; desert tortoises are also likely to die or be injured because of use of the stopping, parking, and camping areas, although we expect that use of these areas is likely to affect fewer animals because the vehicles will usually travel slower away from the routes. We cannot quantify the number of individuals likely to be killed or injured along the network of open and limited routes because of the numerous variables we have discussed previously in this biological opinion.

Within critical habitat of the desert tortoise, we acknowledge that more routes generally occur in areas with a higher probability of supporting desert tortoises than in areas with lower probabilities (greater or lesser than 0.5 in the Nussear et al. 2009 model). See Table 4.4-31 in Toedtli (2019). Areas with a higher proportion of habitat features that are favorable to desert tortoises generally support more desert tortoises. Consequently, off-highway vehicle use poses a greater threat in the conservation areas, which comprise approximately 34.3 percent of the action area. To be clear, a model rating of 0 probability does not guarantee the absence of desert tortoises in these areas; however, because the habitat likely does not contain attributes favorable to their survival, we expect few desert tortoises to occur in such areas. Consequently, off- highway vehicle use in such areas poses negligible threat to the conservation of desert tortoises.

The boundaries of critical habitat and areas of critical environmental concern for the desert tortoise do not completely overlap. In designating critical habitat, the Service occasionally followed section lines; to facilitate on-the-ground management, the Bureau used paved and unpaved routes as the boundaries of its areas of critical environmental concern. We also did not designate areas that did not require additional special management that the Bureau has included in its areas of critical environmental concern, such as the Desert Tortoise Research Natural Area,. Additionally, the Service’s critical habitat covers land managed by multiple jurisdictions, whereas the Bureau focuses its areas of critical environmental concern on its lands. Finally, since the designation of critical habitat, the Service and Bureau have identified areas outside of critical habitat that support higher densities of desert tortoises that were not included in critical habitat.

The Bureau has proposed more routes as open or limited to off-highway vehicle use outside of desert tortoise conservation areas than inside. The Service is focusing its recovery efforts for the desert tortoise on animals within conservation areas; consequently, the greater number of routes outside of these areas will not compromise the recovery of the species. We also expect that areas outside of the conservation areas support lower densities of desert tortoises; therefore, fewer individuals are likely to die or be injured because of vehicle use in these areas.

The Bureau’s proposal to designate 106.9 miles of non-motorized routes is likely to cause mortality to or injury of some desert tortoises. The Bureau (2019b, Appendix C) defines non- motorized travel as “(m)oving by foot, stock, or pack animal, or mechanized vehicle such as a bicycle or landsailer.” In general, the slower the non-motorized user travels, the less likely they are to strike or step on desert tortoises. Smaller animals are always at greater risk. Given that desert tortoises are less vulnerable to this use and the Bureau has proposed less mileage of these routes, we expect that their use is likely to result in few mortalities or injuries. We cannot 52

estimate how many individuals non-mechanized travel is likely to affect for the same reasons we have discussed previously in the biological opinion.

The Bureau has proposed to designate 122.9 miles of routes that are available only for non- mechanized travel, which the Bureau (2019b, Appendix C) defines as “(m)oving by foot, horseback, other animal-powered travel, and cross-country skiing; travel not aided by mechanical means.” We expect that use of non-mechanized routes would affect desert tortoises to a lesser degree than non-motorized routes for essentially the same reasons. We will not repeat that analysis here.

The Bureau would allow transportation linear disturbances to rehabilitate, either naturally or through active restoration, when needed. Preventing off-highway vehicle use of the transportation linear disturbances would reduce the numbers of individuals killed or injured along those linear features; this effect would wield the greatest conservation benefit within conservation areas for the desert tortoise. We do not have the ability to estimate the number of desert tortoises that preventing off-highway vehicle use on the transportation linear disturbances would conserve. Table 11 depicts the miles of transportation linear disturbances within the action area.

Table 11. Miles of transportation linear disturbances within the action area1.

Miles of Transportation Current Situation Proposed Action Linear Disturbances Source Total 8,876.8 8,118.4 Table 2.3-2 Within areas of critical Table 4.4-30; sum of environmental concern 2,577.5 2,577.5 ACECs Outside areas of critical Subtract “within” environmental concern 6,299.3 5,540.9 from “total” 1Data from Toedtli (2019) and include changes prompted by the Dingell Act

The proposed action would decrease the area for stopping, parking, and camping along open and limited routes from approximately 1,706 to 998 acres. The Bureau’s proposal to limit stopping, parking, and camping to previously disturbed areas is beneficial; it reduces the likelihood that vehicles would crush desert tortoises or their burrows because they would be more visible.

Effects on the Critical Habitat of the Desert Tortoise

General Discussion of Effects of Off-Highway Vehicle Use on the Physical and Biological Features of Desert Tortoise Critical Habitat

The action area overlaps the Fremont-Kramer, Superior-Cronese, Ord-Rodman, and Pinto Mountain Critical Habitat Units. The final supplemental environmental impact statement (section 4.4.1.2) summarizes the effects of off-highway vehicle use on the desert tortoise and its habitat. Off-highway vehicles and routes can: 53

1. Occupy land area that would otherwise be occupied by desert tortoises;

2. Remove vegetation and compact soil, thus reducing available forage and substrate for burrow construction shelter when a new road or staging area forms;

3. Change local hydrology;

4. Introduce and spread invasive non-native plants;

5. Change fire cycles because of increasing prevalence of invasive annual grasses;

6. Create edge effects adjacent to roads; and

7. Proliferate disturbance due to vehicles operating off of designated routes.

We consider this list to include those effects that are reasonably certain to occur and will base our analysis on these effects. We will evaluate how these potential effects may affect the physical and biological features of desert tortoise critical habitat in a general manner and then in relation to the proposed Plan Amendments.

Sufficient space to support viable populations within each of the six recovery units and to provide for movement, dispersal, and gene flow

A route network occupies space that would otherwise be available to support viable populations and to provide for movement, dispersal, and gene flow. Routes can fragment habitat and interfere with movement, dispersal, and gene flow; the ability of desert tortoises to move and disperse is a central tenant of this physical and biological feature. Unpaved routes that are used infrequently likely do not pose a threat of fragmentation; we are unaware of any dirt route or track within critical habitat of the desert tortoise that is so heavily traveled that movement of desert tortoises would be precluded. A large off-highway vehicle route network that has various levels of traffic and use intensity may result in fragmentation and interfere with desert tortoise movement; however, we do not have information on how extensive a route network needs to be to adversely affect conservation and recovery efforts for the desert tortoise.

Sufficient quality and quantity of forage species and the proper soil conditions to provide for the growth of these species

Off-highway vehicular use may not affect this physical and biological feature because its attributes are often not present within roadbeds. Some routes support annual plants, possibly even at greater local densities than on adjacent, undisturbed habitat, because of alterations in the hydrological regime caused by the road (i.e., edge effects). Although such areas may be of value to a few desert tortoises, they are not so extensive that they substantially alter the patterns of the distribution of forage plants. 54

The primary effects from routes on this physical and biological feature largely occur away from the route and stem from the access that routes provide for unauthorized activities and as a corridor for the introduction and spread of invasive non-native plant species. Unauthorized vehicle use off designated routes can crush and remove vegetation that desert tortoises use for forage and cause soil compaction that compromises proper conditions for plant growth. Even a few passes by off-highway vehicles can disturb and compact substrates and destroy annual plants. Invasive non-native species can out-compete native species that desert tortoises use for forage. Invasive annual grasses in particular can alter fire cycles in the Mojave Desert (i.e., larger and more frequent fires), which can destroy forage species.

Fugitive dust produced by off-highway vehicles on unpaved roads may cause effects such as reduced growth rates, size, and survivorship in roadside plants (Ouren et al. 2007 in Bureau 2019b). Dust may therefore further alter the composition of plant communities alongside roads and in cross-country areas where unauthorized vehicle use occurs.

Suitable substrates for burrowing, nesting, and overwintering

Off-highway vehicular use on routes does not affect this physical and biological feature because these attributes are not present within roadbeds. Unauthorized vehicle use off designated routes can compact substrates that desert tortoises depend on for burrowing, nesting, and overwintering.

Burrows, caliche caves, and other shelter sites

Off-highway vehicular use on routes may have minor effects on this physical and biological feature. Most burrows, caliche caves, and other shelter sites are not present within roadbeds. Occasionally, the edges of routes support burrows and caliche caves; vehicles moving along the edge of the route may damage or destroy them. Unauthorized vehicle use off designated routes can crush, damage, and destroy burrows, caliche caves, and other shelter sites such as shrubs.

Sufficient vegetation for shelter from temperature extremes and predators.

Off-highway vehicular use on routes will not adversely affect this physical and biological feature of critical habitat because these attributes are not present within roadbeds. Unauthorized use off designated routes, however, can crush, destroy, and remove vegetation that tortoises rely on for shelter. The introduction and spread of invasive non-native plants can also lead to increased competition with native species, and an increase in invasive annual grasses that affect fire cycles as we have previously discussed. Fires can destroy vegetation that desert tortoises rely on for forage and shelter.

Habitat protected from disturbance and human-caused mortality.

Off-highway vehicular use on routes provides access for human encroachment into critical habitat. Greater density of routes exposes greater areas of disturbance, such as the dumping of trash and the attraction of predators, such as common ravens. 55

Plan Amendment I

The proposed action with regard to this plan amendment and its implementation-level decisions comprises the designation of 5,997 miles of off-highway vehicle open and limited routes and 230 miles of 230 miles of routes that are closed to off-highway vehicles but open to non-motorized or non-mechanized use.

The Bureau’s proposed action would not result in the creation of new routes. The Bureau has proposed to designate as open some portions of existing routes that it had not previously considered open. Therefore, the proposed action would not decrease the space that desert tortoises currently occupy or contribute to additional barriers to movement beyond the current baseline. Reclamation, restoration, and rehabilitation of transportation linear disturbances would increase, to some degree, the area available for desert tortoises to occupy.

Vehicles operating on designated routes may introduce and disperse invasive non-native plants to new areas of the desert; we will not repeat our earlier discussion of these effects. The proposed action would not increase the likelihood of introduction and spread of these species because the Bureau is not creating new routes. The reclamation, restoration, or rehabilitation of transportation linear disturbances is likely to reduce the abundance of non-native plants along these areas over time. Therefore, the proposed action would not further degrade the quality or quantity of forage available to desert tortoises. Because the proposed action is not likely to increase the abundance of non-native plants in the action area, it is also unlikely to provide additional fuels that could ignite and spread fire in a way that would destroy vegetation used for shelter.

The proposed action will not increase damage to burrows, caliche caves, and other shelter sites, because the Bureau is not proposing to develop new routes. The reclamation, restoration, or rehabilitation of transportation linear disturbances will reduce the area in which burrows and caliche caves along the edges of routes are exposed to vehicle use.

Invasive non-native plants may also be able to more efficiently establish with additional water resources. The proposed action would not increase edge effects because the Bureau is not creating new routes. The reclamation, restoration, or rehabilitation of transportation linear disturbances is likely to reduce the area in which edge effects can occur over time. Therefore, the proposed action would not further reduce suitable habitat for desert tortoises to occupy, or further degrade the quality or quantity of forage available to desert tortoises, beyond the current baseline. The proposed action is unlikely to increase disturbance and human-caused mortality because the reclamation, restoration, or rehabilitation of transportation linear disturbances is likely to reduce the degree of encroachment and the magnitude of resulting effects over time.

Plan Amendment III

The proposed action with regard to this plan amendment and its implementation-level decisions comprises the designation of “C” routes located adjacent to the Spangler Hills Off-highway Vehicle Recreation Area between the city of Ridgecrest and the recreation area and a route 56

connector linking the Johnson Valley and Stoddard Valley Off-Highway Vehicle Recreation Areas. The designated “C” routes are not located in critical habitat. Therefore, we will not discuss them further in this section of the biological opinion.

The route-connector would be located within critical habitat. We expect that the use of this connector for speed–controlled events would result in effects similar to those we have already discussed with regard to critical habitat. We will not repeat that discussion here.

Plan Amendment IV

The proposed action with regard to this plan amendment and its implementation-level decisions comprises the designation of Cuddeback and Coyote dry lakes as open to off-highway vehicle use.

Dry lakes are largely devoid of vegetation and, in general, do not contain the physical and biological features of critical habitat. Accessing these areas on designated open routes would affect most physical and biological features in a manner similar to that which we have already discussed for the route network; therefore, we will not repeat that discussion here.

The exception to this generalization is that large groups of recreationists camping on Cuddeback and Coyote dry lakes would likely affect the sixth physical and biological feature by increasing disturbance in the vicinity. Specifically, large gatherings have the potential to discard waste and thereby attract predators of desert tortoises.

Plan Amendment VI

The proposed action with regard to this plan amendment and its implementation-level decisions comprises the limitation of stopping, parking, and camping to previously disturbed areas within 50 feet of the route centerline inside areas of critical environmental concern for the desert tortoise and California Desert National Conservation Lands. Outside of these areas, the Bureau proposes to limit stopping and parking to previously disturbed areas within 100 feet of the route centerline. The Bureau also proposes to designate special stopping, parking, and camping areas in previously disturbed areas outside of the 50- and 100-foot respective limits.

In critical habitat, this implementation-level decision would reduce the amount of area that is available for stopping, parking, and camping compared the existing situation and limit all parking, stopping, and camping to previously disturbed areas. The Bureau estimates that approximately 1 percent of the area within 50 or 100 feet of the centerline of routes has been previously disturbed. Therefore, within critical habitat, the Bureau estimates that approximately 307 acres along open and limited routes are available for stopping, parking, and camping (Toedtli 2019, Table 4.4-18). Because parking, stopping, and camping would be limited to previously disturbed areas, most of the physical and biological features are likely absent from these areas. 57

The exception to this generalization is that groups of recreationists camping in previously disturbed areas would likely affect the sixth physical and biological feature by increasing disturbance in the vicinity. Specifically, such gatherings have the potential to discard waste and thereby attract predators of desert tortoises.

Implementation of the Travel and Transportation Program

We do not know the future specific issues that the Bureau would need to address as part of the management of the travel and transportation network. However, during implementation, we expect that these issues would involve minor and localized effects to critical habitat that are generally similar to those that we have discussed previously in this section (e.g., vehicles using open and limited routes, minor amounts of ground disturbance to implement corrective measures). If implementation of the minimization and mitigation actions would result in ground disturbance (and therefore disturbance of critical habitat), the Bureau will apply the appropriate conservation and management actions from its land use plan. The Bureau has used such measures on activities in the past; because of the implementation of these measures, the Bureau can manage activities to avoid or reduce adverse effects to critical habitat. Appropriate measures include, but are not limited to, the use of monitors and fencing to workers and equipment remain in designated work areas, worker education programs, and management of trash. Consequently, the Bureau’s implementation of the travel and transportation program is unlikely to affect critical habitat of the desert tortoise in a measurable manner.

CUMULATIVE EFFECTS

“‘Cumulative effects’ are those effects of future state or private activities, not involving federal activities, that are reasonably certain to occur within the action area of the federal action subject to consultation” (50 CFR 402.02). Any future discretionary activities on lands managed by the Bureau are subject to the consultation requirements of section 7(a)(2) of the Endangered Species Act.

Most of the rest of the action area is only accessible by using routes that cross public lands. Therefore, persons who wish to undertake commercial activities would need a right-of-way grant from the Bureau. Therefore, we do not consider such activities to be cumulative effects. We are unaware of any non-federal activity in the action area that is reasonably certain to occur.

Because the action area does not change with regard to the species under consultation, we will not repeat this section for the other species and critical habitat in this biological opinion.

CONCLUSIONS

Desert Tortoise

As we stated previously in this biological opinion, “jeopardize the continued existence of” means to engage in an action that reasonably would be expected, directly or indirectly, to reduce appreciably the likelihood of both the survival and recovery of a listed species in the wild by 58

reducing the reproduction, numbers, or distribution of that species (50 CFR 402.02). This regulatory definition focuses on how the proposed action would affect the reproduction, numbers, and distribution of the species under consideration in the biological opinion. For that reason, we have used those aspects of the desert tortoise’s status as the basis to assess the overall effect of the proposed action on the species.

Additionally, we determine whether a proposed action is likely “to jeopardize the continued existence of the species” through an analysis of how a proposed action affects the listed taxon within the action area in relation to the range of the entire listed taxon. For the desert tortoise, this process involves considering the effects at the level of the action area, then at the level of the recovery unit, and then finally for the range of the listed taxon. Logically, if a proposed action is unlikely to cause a measurable effect on the listed taxon within the action area, it is unlikely to affect the species throughout the recovery unit or the remainder of its range. Conversely, an action with appreciable effects on the listed entity in the action area may degrade the status of the species to the extent that it affects the recovery unit or the entire range.

In the following sections, we will synthesize the analyses contained in the Effects of the Action section of this biological opinion to determine how each of the proposed action affects the reproduction, number, and distribution of the desert tortoise. We will then assess the effects of the proposed actions on the recovery of the species and whether they are likely to appreciably reduce the likelihood of both the survival and recovery of the desert tortoise in the wild.

Reproduction

The proposed action is unlikely to affect measurably the reproductive capacity of the desert tortoise. Although non-native plants can spread along open and limited routes, the Bureau is not opening any new routes in the action area. Through the rehabilitation of transportation linear disturbances, it will reduce the potential for non-native plants to spread in the action area.

Numbers

Off-highway vehicle use on routes will kill or injure desert tortoises, particularly small ones that are difficult to see. We recognize that not all desert tortoises killed on routes will be detected. We also recognize that the degree to which observed annual mortality rates represent the true mortality rate may vary over time due to factors unrelated to the detectability of desert tortoises (e.g. intensity of monitoring efforts, location and designation status of route, scavenger prevalence, effectiveness of the Bureau’s travel and transportation program, etc.). From 2007 through 2018, the Bureau (2014, 2015b, 2019c) found five desert tortoises that likely died because of casual use on the route network in the action area. Therefore, considering these data from the Bureau’s annual reporting for casual use in its route network within the context of these factors, we conclude that the actual amount of annual mortality is likely to be somewhat higher.

To evaluate the effect of these mortalities on desert tortoises within the Western Mojave Recovery Unit, we assumed that the current trend of decline of desert tortoises would continue until 2024 and used the data from the Service’s (2015a) trend analysis to project the number of 59

large individuals within the Western Mojave Recovery Unit. The results of this extrapolation are in Table 12.

Table 12. Extrapolated numbers of large desert tortoises in conservation areas of the Western Mojave Recovery Unit in 2014, 2019, and 2024.

Number of Large Lower 95 Percent Upper 95 Percent Year Desert Tortoises1 Confidence Interval Confidence Interval 2014 17,645 11,155 27,912 2019 12,392 5,222 29,405 2024 8,702 2,417 31,329 1 From Service (2019).

The numbers in the previous table do not include the number of large desert tortoises that reside outside of conservation areas. Therefore, we emphasize that the following calculations upon which we based this analysis are not precise; however, they allow for a reasonable approach to the analysis based on the best available information and our professional judgment.

This extrapolation allows us to evaluate the loss of 8 desert tortoises compared to the current population estimate (2019) and in 5 years (2024), when the Bureau and Service will re-evaluate the effects of casual use of the route network on the desert tortoise.

The loss of 8 desert tortoises at this time represents approximately 0.07 percent of the estimated number of large desert tortoises within conservation areas in Western Mojave Recovery Unit (8 / 12,392 x 100 = 0. 065).

The loss of 40 desert tortoises by 2024 represents approximately 0.46 percent of the estimated number of large desert tortoises within conservation areas in Western Mojave Recovery Unit at that time (40 / 8,702 x 100 = 0.459).

The loss of 8 desert tortoises annually and 40 by 2024 through casual use of the route network in the action area is not likely to appreciably reduce the number of desert tortoises in the Western Mojave Recovery Unit. For this reason, we will not extend our analysis to the entire range of the listed taxon.

The loss of 8 desert tortoises annually and 40 by 2024 through casual use of the route network in the action area is not likely to appreciably reduce the number of desert tortoises in the Western Mojave Recovery Unit. For this reason, we will not extend our analysis to the entire range of the listed taxon. The Bureau and the Service have agreed to re-initiate formal consultation if the Bureau determines that four large desert tortoises died because of casual use of the route network in the action area in any calendar year. We recognize that the Bureau will not detect every desert tortoise that dies because of casual use of the route network. For that reason, based on the best available information and our professional judgment, finding four large desert tortoises that die in any calendar year because of casual use of the route network represents a conservative, reasonable, and prudent means of ensuring that the proposed action does not appreciably reduce 60

the number of desert tortoises in the Western Mojave Recovery Unit. Please refer to the discussion on page 11 of this biological opinion for a full explanation of the use of four large desert tortoises as a trigger for re-initiation of formal consultation.

Distribution

The Bureau’s proposed action would not result in the creation of new routes. Therefore, the proposed action would not cause the loss of habitat and any change in the distribution of the desert tortoise for that reason.

Few desert tortoises remain at the edges of the desert tortoise’s range in the western portion of the action area. We expect that, at some point, human activities in these areas will cause the extirpation of these animals, which would alter their distribution. However, given the numerous risks to desert tortoises at the edge of their range in the action area (e.g., rural development, livestock grazing, off-highway vehicle use, feral dogs, common ravens, etc.), we cannot attribute a future extirpation to the proposed action.

Recovery

We discussed the objectives and criteria to achieve recovery of the desert tortoise in the Status of the Desert Tortoise section of this biological opinion. The Bureau (2019b, page 2-1) developed the final supplemental environmental impact statement “to be consistent with the goals and objectives” of the California Desert Conservation Area Plan, as amended. The conservation goals of the “… 2006 West Mojave Plan are to develop a regional biological strategy to conserve plant and animal species and their habitats and to prevent future listings.”

The proposed action would not remove all threats to the desert tortoise that may result from casual use of the proposed route network. However, the proposed plan amendments would contribute to a broad recovery strategy for the desert tortoise with regard to casual use of the route network in the Western Mojave Recovery Unit. Important components of a recovery strategy include reducing the losses of desert tortoises and their habitat. Permitting stopping, parking, and camping only in disturbed areas would ensure that use of the route network does not lead to additional habitat loss. The designation of transportation linear disturbances and their rehabilitation would decrease effects of a route network, such as the spread of non-native plants. Finally, the adaptive management program for implementing the route network would enable the Bureau to adapt its methods for remediating issues as they arise. For these reasons, we conclude that the proposed action is not likely to adversely affect recovery of the desert tortoise.

Conclusion

After reviewing the current status of the desert tortoise, the environmental baseline for the action area, the effects of the proposed activities, and the cumulative effects, we have determined that the activities considered in this biological opinion are not likely to jeopardize the continued existence of the desert tortoise. We have reached this conclusion for the following reasons: 61

1. The proposed action is not likely to affect measurably the reproductive capacity of desert tortoises.

2. The proposed action is not likely to appreciably reduce the number of desert tortoises within the action area and, by extension, throughout the range of the desert tortoise.

3. The proposed action will not decrease the distribution of the desert tortoise.

4. The proposed action is not likely to adversely affect recovery of the desert tortoise.

Critical Habitat of the Desert Tortoise

“Destruction or adverse modification means a direct or indirect alteration that appreciably diminishes the value of critical habitat for the conservation of a listed species” (50 CFR 402.02). We determine whether a proposed action is likely to result in the destruction or adverse modification of critical habitat through an analysis of how a proposed action affects the physical and biological features of critical habitat within the action area in relation to the entirety of designated critical habitat. For critical habitat of the desert tortoise, this process involves considering the effects at the level of the action area, then at the level of critical habitat unit, and then finally for the entirety of designated critical habitat.

Logically, if a proposed action is unlikely to measurably affect the conservation value of critical habitat within the action area, it will not affect the conservation value of the critical habitat unit or the remainder of critical habitat. Conversely, an action with appreciable effects on the conservation value of critical habitat in the action area may degrade the status of critical habitat to the extent that it affects the critical habitat unit or the entire designated area of critical habitat.

After reviewing the current status of the critical habitat, the environmental baseline for the action area, the effects of the proposed activities, and the cumulative effects, it is our biological opinion that the proposed action is not likely to result in the destruction or adverse modification of critical habitat of the desert tortoise. We have reached this conclusion for the following reasons, which we have provided in relation to the physical and biological features of critical habitat of the desert tortoise.

1. Sufficient space to support viable populations within each of the six recovery units and to provide for movement, dispersal, and gene flow: The proposed action will not reduce the amount of space available to support viable populations within the action area. It will also promote movement, dispersal, and gene flow because of the rehabilitation of transportation linear disturbances.

2. Sufficient quality and quantity of forage species and the proper soil conditions to provide for the growth of these species: The proposed action is not likely to reduce the quality and quantity of forage species or adversely affect the soil conditions for the growth of these species because it will not cause any additional ground disturbance and would promote the rehabilitation of this feature within transportation linear disturbances. 62

3. Suitable substrates for burrowing, nesting, and overwintering: The proposed action is not likely to adversely affect substrates for burrowing, nesting, and overwintering because it will not result in new ground disturbance. The condition of this feature within transportation linear disturbances is likely to improve.

4. Burrows, caliche caves, and other shelter sites: Only burrows and caliche caves along the edges of open and limited routes are likely to sustain damage because of the proposed action. Because open and limited routes occupy a small portion of the action area, the proposed action will not affect most burrows and caliche caves. The rehabilitation of transportation linear disturbances will allow for the establishment of additional burrows.

5. Sufficient vegetation for shelter from temperature extremes and predators: The proposed action would not result in the removal of vegetation that desert tortoises use for shelter from temperature extremes and predators because the Bureau is not developing new routes. The rehabilitation of transportation linear disturbances will allow for the establishment of shrubs that can provide desert tortoises with shelter from temperature extremes and predators.

6. Habitat protected from disturbance and human-caused mortality: The proposed action is not likely to increase the overall level of disturbance that off-highway vehicle in the action area. Larger gatherings of recreationists in some previously disturbed areas and at Cuddeback and Coyote dry lakes may increase disturbance on local levels. Disturbances at local levels would not affect most of the area designated as critical habitat within the action area. Additionally, because such gatherings would occur intermittently and for short periods of time (i.e., primarily weekends), this disturbance would not affect the overall character of surrounding habitat.

INCIDENTAL TAKE STATEMENT FOR THE DESERT TORTOISE

Section 9 of the Act and Federal regulation pursuant to section 4(d) of the Act prohibit the take of endangered and threatened species, respectively, without special exemption. Take is defined as to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture or collect, or to attempt to engage in any such conduct. Harm is further defined by the Service to include significant habitat modification or degradation that results in death or injury to listed species by significantly impairing essential behavioral patterns, including breeding, feeding, or sheltering. Incidental take is defined as take that is incidental to, and not the purpose of, the carrying out of an otherwise lawful activity. Under the terms of section 7(b)(4) and section 7(o)(2), taking that is incidental to and not the purpose of the agency action is not considered to be prohibited taking under the Act provided that such taking is in compliance with the terms and conditions of an incidental take statement and occurs as a result of the action as proposed.

The Bureau has a continuing duty to regulate the activities covered by this incidental take statement. If the Bureau does not implement the proposed action as described in the final supplemental environmental impact statement, errata, and this biological opinion, the protective coverage of section 7(o)(2) may lapse. To monitor the impact of incidental take, the Bureau must 63

report the progress of its action and the impact on the species to the Service as specified in the incidental take statement (50 CFR402.14(i)93)).

The implementing regulations for section 7(a)(2) address Federal actions that allow for activities to occur both with and without future reviews. “Mixed programmatic action means, for purposes of an incidental take statement, a Federal action that approves action(s) that will not be subject to further section 7 consultation, and also approves a framework for the development of future action(s) that are authorized, funded, or carried out at a later time and any take of a listed species would not occur unless and until those future action(s) are authorized, funded, or carried out and subject to further section 7 consultation” (50 Code of Federal Regulations 402.02).

We have analyzed three basic types of activities in this biological opinion. Specifically:

1. We have considered the effects of casual use of the Bureau’s route network. The Bureau will not conduct further plan-level review of this route network after adoption of its record of decision. Consequently, this incidental take statement includes any incidental take associated with casual use of the route network as proposed by the Bureau and described in its record of decision. Therefore, under the terms of section 7(b)(4) and section 7(o)(2), this incidental taking is not considered to be prohibited.

2. We have considered the effects of the Bureau’s implementation of the route network (i.e., adaptive management and the on-the-ground activities that the Bureau will employ to ensure that it is meeting the goals and objectives described in its final supplemental environmental impact statement). Consequently, this incidental take statement includes any incidental take associated with adaptive management and the on-the-ground activities needed to implement the route network as proposed by the Bureau and described in its record of decision. Therefore, under the terms of section 7(b)(4) and section 7(o)(2), this incidental taking is not considered to be prohibited.

3. We have considered the general effects of activities that the Bureau may authorize under special permits. Because the Bureau will evaluate and possibly authorize such activities on a case-by-case basis, this incidental take statement does not include any incidental take associated with such activities. On a case-by-case basis, the Bureau and Service will consult on these activities to determine whether they may affect the desert tortoise

We anticipate that, at most, the proposed action is likely to result in the incidental take of 8 desert tortoises annually in the form of mortality. As we discussed previously in this biological opinion, if an injured desert tortoise survives treatment and can return to the wild, we will not include it as a mortality. We will consider injured desert tortoises that survive but are not suitable for release to the wild because of their injury as mortalities.

We also anticipate that the proposed action is likely to result in the incidental take of desert tortoises in the form of capture, if the Bureau needs to move individuals from harm’s way as it implements its on-the-ground management program. We have not anticipated the number of individuals that the Bureau is likely to capture for two reasons. First, we cannot reasonably 64

predict how many desert tortoises the Bureau will encounter that need moving from harm’s way during its work. Second, as we discussed previously in the biological opinion, this form of take is unlikely to kill or injure desert tortoises.

The implementing regulations for section 7(a)(2) clarify that the Service may use surrogates to express the amount or extent of anticipated take when “exact numerical limits on the amount of anticipated incidental take may be difficult” (80 FR 26832). The implementing regulations (50 CFR 402.14(i)(1)(i)) require that the Service meet three conditions for the use of a surrogate. To use a surrogate, the Service must:

1. Describe the causal link between the surrogate and take of the listed species: We are not aware of any research that addresses the ratio of found carcasses to the actual number of mortalities for desert tortoises. In an amendment to a previous biological opinion (Service 2007), we estimated that eight desert tortoises likely died per year in the Western Mojave Recovery Unit because of casual use of the route network, based on our professional judgment. In that same amendment, we also anticipated that desert tortoises were also likely to die because of livestock grazing and casual use not associated with routes. We acknowledged that we would not detect every mortality and required that the Bureau re- initiate formal consultation if it found three desert tortoises that died because of livestock grazing and casual use related to mining and the route network in any 12-month period. The amount of conservation activity with regard to the desert tortoise in the Western Mojave Recovery Unit has increased substantially since 2007. The Bureau and conservation organizations are routinely conducting restoration work; other crews are monitoring desert tortoises and common ravens. For this reason, we expect the biologists and other field workers will find more desert tortoises that have died because of casual use of the route network than in the past. Consequently, we consider the finding of four large desert tortoises that died because of casual use of the route network as a reasonable surrogate. Please refer to the discussion on page 11 of this biological opinion for a full explanation of the use of four large desert tortoises as a trigger for re-initiation of formal consultation.

2. Describe why it is not practical to express the amount of anticipated take or to monitor take-related impacts in terms of individuals of the listed species: The Bureau cannot monitor the route network in a practical or reasonable manner that would allow it to find most desert tortoises that die because of collisions with vehicles. Scavengers remove the carcasses of any animal soon after death. Additionally, the network is too large and the Bureau cannot predict where use will occur in relation to where desert tortoises are likely to be active.

3. Set a clear standard to determine when the proposed action has exceeded the anticipated amount or extent of the taking: The Bureau will re-initiate formal consultation when it finds four large desert tortoises that have likely died because of casual use of the route network in a calendar year. 65

Accordingly, we establish the surrogate of four large desert tortoises found dead in a calendar year because of casual use of the route network as described in the final supplemental environmental impact statement, errata (Toedtli 2019), and this biological opinion.

Finally, we also acknowledged that recreationists might engage in unauthorized activities after gaining access to the action area via the Bureau’s route network. We have not included any mortality within the action area in this incidental take statement if the take of desert tortoises occurs because of unauthorized activity. Therefore, we consider this taking to be prohibited and to constitute a violation of section 9 of the Endangered Species Act.

REASONABLE AND PRUDENT MEASURES AND TERMS AND CONDITIONS

We have not identified any reasonable and prudent measures or terms and conditions that we consider necessary or appropriate to minimize take of the desert tortoise at this time.

REPORTING REQUIREMENTS, DISPOSITION OF DEAD OR INJURED SPECIMENS, CONSERVATION RECOMMENDATIONS, AND RE-INITIATION NOTICE

These sections of the biological opinion are located after the discussions of the listed plant species.

We will now provide the Status of the Species and Critical Habitat sections for the listed plant species and follow that with their Environmental Baseline sections. Finally, we will include the Effects of the Action on the Listed Plants and Critical Habitat sections, with their conclusions.

STATUS OF THE LISTED PLANT SPECIES AND THEIR CRITICAL HABITAT

Triple-Ribbed Milk-Vetch

Unless otherwise noted, the information in this section is from the 5-year review (Service 2009a).

Listing History

The Service listed the triple-ribbed milk-vetch as endangered on October 6, 1998 (63 Federal Register 53596). The final listing rule notes that the species is “threatened by maintenance activities for the crude oil pipeline which runs through its habitat at Big Morongo Canyon and by vehicle use in the canyons. Its limited number of individuals make it especially vulnerable to unanticipated events, such as pipeline leaks, breaks, or emergency repairs.”

Species Biology and Life History

Triple-ribbed milk-vetch is a short-lived perennial plant in the pea family. It grows in an erect manner and can reach up to 10 inches in height. Its habitat includes dry washes, bases of canyon 66

slopes, and scree slopes. Fraga et al. (2015) contend that optimal habitat occurs on “steep, rocky slopes and ridge tops” and that plants in canyon bottoms and washes have “washed down from upland source populations.”

Recovery Plan

The Service has not completed a recovery plan for the triple-ribbed milk-vetch.

Five-Year Review

In our 5-year review, we determined that retaining the status of the triple-ribbed milk-vetch as endangered was appropriate. We reached this conclusion because a few, small, isolated populations represented the species and threats remained present.

Outside of the action area for this biological opinion, occurrences of this species are located on lands managed by The Wildlands Conservancy and Joshua Tree National Park. In general, lands managed by The Wildlands Conservancy and National Park Service are not subject to intense recreational use, except for in the vicinity of popular hiking trails.

Core Criteria for the Jeopardy Determination

Reproduction

Amsberry and Meinke (2007 in Service 2009a) included two populations of triple-ribbed milk- vetch in a population viability assessment. They “suggested reproduction and seedling germination occur in most years and [triple-ribbed milk-vetch] seedlings were more robust when grown in soils inoculated with mutualistic soil fungi (mycorrhizae) and nitrogen-fixing soil bacteria (Rhizobium).” Fraga et al. (2015) note that “[s]exual reproduction in the genus Astragalus is usually mediated by medium to large bees;” however, we do not know which species pollinate triple-ribbed milk-vetch.

Numbers

The numbers of individuals differ from year to year and the species may not be present above ground in drought years. The largest occurrence discussed in the 5-year review is 300 individuals. Other occurrences of one or a few individuals are unlikely to persist over time. We do not have any information on population trends.

Fraga et al. (2015) estimated that triple-ribbed milk-vetch “has a global population of nearly 3100 individuals distributed among 45 known occurrences in ten watersheds throughout its geographic range.”

Distribution

The triple-ribbed milk-vetch occurs in the southeastern San Bernardino Mountains and western 67

Little San Bernardino Mountains in Riverside County and the Orocopia Mountains and Santa Rosa Mountains in Riverside County.

Critical Habitat of the Triple-ribbed Milk-vetch

The Service has not designated critical habitat for the triple-ribbed milk-vetch.

CUSHENBURY OXYTHECA

Unless otherwise noted, the information in this section is from the 5-year review for the Cushenbury oxytheca (Service 2009b).

Listing History

The Service listed the Cushenbury oxytheca as endangered on August 24, 1994 (59 Federal Register 43652). The final listing rule notes that mining, energy development, and vehicle use threaten the species. This listing rule also addressed the Cushenbury buckwheat, Cushenbury milk-vetch, and Parish’s daisy. We will refer to these plants collectively as the carbonate plants.

Species Biology and Life History

Cushenbury oxytheca is an annual plant in the buckwheat family. It grows from a basal rosette (i.e., leaves of generally the same length circle the base of the stem) and can reach up to 24 inches in height. It occurs on substrates composed of limestone, dolomite, or a mixture of limestone and dolomite in areas with an open canopy structure and little or no accumulation of organic material.

Recovery Plan

The Service has not completed a recovery plan for Cushenbury oxytheca. The draft recovery plan (Service 1997) recommends three criteria for downlisting or delisting of Cushenbury oxytheca. They are, in summary:

1. Protection of priority habitats;

2. Protection of additional lands to complete otherwise isolated reserves; and

3. Implementation of adaptive monitoring and management to address future issues.

The Service, Bureau, Forest Service, California Native Plant Society, mining companies and major claim holders developed a habitat management strategy for several federally listed species that occur on carbonate substrates (Olson 2003). The objectives of the strategy relevant to the conservation of the listed carbonate plants are:

1. Maintain and manage the geomorphic and ecological processes of the landscape in large, well-placed blocks of habitat where the carbonate plants are found such that the plants are 68

likely to persist indefinitely;

2. Avoid jeopardizing the continued existence of the carbonate plants, as defined in section 7(a)(2) of the Endangered Species Act and its regulations;

3. Avoid destruction or adverse modification of critical habitat of the carbonate plants, as defined in section 7(a)(2) of the Endangered Species Act and its regulations;

4. Contribute to the recovery and ultimate de-listing of the carbonate plants under the Endangered Species Act; and

5. Provide a mechanism for tracking both the loss and conservation of habitat for the carbonate plants over time.

Five-Year Review

In our 5-year review, we determined that retaining the status of the Cushenbury oxytheca as endangered was appropriate. We reached this conclusion because mining continued to threaten most of the species’ habitat and additional threats (i.e., fire suppression, climate change) had emerged since its listing.

The Bighorn Wilderness Area includes 137 acres of critical habitat for Cushenbury oxytheca. Additionally, 35 acres of occupied habitat and 143 acres of critical habitat are within the Baldwin Lake/Holcomb Valley Special Interest Area, which the Forest Service designated for botanical, zoological, prehistorical, and historical values.

Since the issuance of the 5-year review, the Service (2017b) issued a biological opinion to the U.S. Forest Service for the expansion of the Mitsubishi South Quarry. The Service concluded that the loss of loss of 153.6 acres of suitable carbonate habitat and 24.5 acres of occupied habitat was not likely to jeopardize the continued existence of Cushenbury oxytheca. To offset the adverse effects, the mining company will contribute carbonate habitat lands to the reserve established through the management strategy “via quit-claim or conveyance of specified patented lands to the Forest Service.” The Forest Service would prohibit future mining claims or associated mining activities on these lands, which support 58.1 acres of habitat occupied by Cushenbury oxytheca.

On March 7, 2019, the Service (2019d) issued a biological opinion to the Forest Service regarding its ongoing management activities on the Mountaintop Ranger District within the San Bernardino National Forest. The Service (2019d) concluded that the Forest Service’s management activities on the Mountaintop Ranger District were not likely to jeopardize the continued existence of Cushenbury milk-vetch, Cushenbury buckwheat, Cushenbury oxytheca, and Parish’s daisy (i.e., the carbonate plants) or result in the destruction or adverse modification of their critical habitat. We reached these conclusions because the Forest Service is implementing a management strategy for carbonate habitat that allows mining to proceed “while meeting and exceeding recovery criteria 1 and 2 for habitat preservation,” as described in the 69

draft recovery plan for these species. The Forest Service also minimizes or avoids impacts from its programs through the implementation of protective measures and management direction. This information is applicable to the next three species in the Status of the Species section of this biological opinion (i.e., the remaining carbonate plant species).

Core Criteria for the Jeopardy Determination

Reproduction

The Service does not have information on the reproduction of this species. Based on observations, insect pollinators are likely generalists.

Numbers

“Population size” fluctuates from year to year, depending on the amount of rainfall and temperatures. The number of known occurrences of Cushenbury oxytheca may have increased since the Service listed the species. Any such increase likely reflects greater survey effort than an actual increase in abundance.

Distribution

The Cushenbury oxytheca grows on the carbonate soils that occur along the northern edge of the San Bernardino Mountains, north and east of Big Bear Lake in San Bernardino County. Its range covers approximately 500 acres, which is approximately the same size as at the time of listing.

Critical Habitat of the Cushenbury Oxytheca

The Service designated critical habitat for Cushenbury oxytheca on December 24, 2002 (67 FR 78570). It occurs within a single unit of 3,150 acres along the northeastern slope of the San Bernardino Mountains.

Physical and Biological Features of Critical Habitat

The physical and biological features of critical habitat of the Cushenbury oxytheca are:

1. Soils derived primarily from upslope limestone, a mixture of limestone and dolomite, or limestone talus substrates with parent materials that include Bird Spring Formation, Bonanza King Formation, middle and lower members of the Monte Cristo Limestone, and the Crystal Pass member of the Sultan Limestone Formation at elevations between 4,724 and 7,782 feet;

2. Soils with intact, natural surfaces that have not been substantially altered by land use activities (e.g., graded, excavated, re-contoured, or otherwise altered by ground- disturbing equipment); and

3. Associated plant communities that have areas with a moderately open canopy cover, 70

generally between 25 and 53 percent.

The Service (2017b) concluded that the proposed expansion of the Mitsubishi South Quarry was not likely to result in the destruction or adverse modification of critical habitat of the Cushenbury oxytheca. The expansion would result in the loss of 43 acres of critical habitat; this critical habitat contained the physical and biological features of critical habitat. To offset the loss of critical habitat, the mining company provided 228 acres of critical habitat that support the physical and biological features of the Cushenbury oxytheca’s critical habitat. Through either relinquishing mining claims or conveying patented lands to the Forest Service, which would then withdraw these lands from mineral entry, future mining would not occur on the 228 acres of critical habitat.

PARISH’S DAISY

Unless otherwise noted, the information in this section is from the 5-year review for the Parish’s daisy (Service 2009c).

Listing History

The Service listed Parish’s daisy as threatened on August 24, 1994 (59 Federal Register 43652). The final listing rule notes that mining, energy development, and vehicle use threaten the species.

Species Biology and Life History

Parish’s daisy is a small perennial herb in the sunflower family that can reach 12 inches in height. Its habitat includes rocky slopes, active washes, and outwash plains on substrate derived from limestone or dolomite within pinyon woodlands, pinyon-juniper woodlands, and blackbush scrub communities from 3,842 to 6,400 feet in elevation.

Recovery Plan

The Service has not completed a recovery plan for this species. Parish’s daisy is included in the draft recovery plan and habitat management strategy that we discussed previously in this document for Cushenbury oxytheca.

Five-Year Review

In our 5-year review, we determined that retaining the status of Parish’s daisy as threatened was appropriate. We reached this conclusion because mining continues to threaten to approximately 73 percent of the species’ habitat and stochastic events may affect the species throughout its range. Since its listing, the Service has identified fire suppression and climate change as threats to Parish’s daisy.

The Service (2015c) concluded that the Forest Service’s implementation of fuel reduction 71

projects every 5 to 15 years in the San Bernardino National Forest was not likely to jeopardize the continued existence of Parish’s daisy. Individuals of this species occurs in the Baldwin Lake treatment area. The Service reached its conclusion because of the short duration of the treatment activities, their infrequent occurrence, and proposed measures to protect the species during treatments.

The Service (2017b) concluded that the Forest Service’s approval of the expansion of the Mitsubishi South Quarry was not likely to jeopardize the continued existence of the Parish’s daisy. The proposed action would result in the loss of 153.6 acres of suitable carbonate habitat and 0.1 acre of occupied habitat. To offset these adverse effects, the mining company will contribute carbonate habitat lands to the reserve established through the management strategy “via quit-claim or conveyance of specified patented lands to the Forest Service.” The Forest Service would prohibit future mining claims or associated mining activities on these lands, which support 43.72 acres of habitat occupied by Parish’s daisy.

Core Criteria for the Jeopardy Determination

Reproduction

To date, no one has conducted focused research on the pollination ecology, seed dispersal mechanisms, population dynamics, or seedbank dynamics of Parish’s daisy. Mistretta and White (2001 in Service 2009c) introduced Parish’s daisy onto an irrigated, disturbed site in 1991 and 1992. Approximately 66 percent of the individuals survived to 1998. Because introduced individuals successfully reproduced, Mistretta and White (2001 in Service 2009c) suggested that “Parish’s daisy was not dependent upon specialized pollinators or soil microorganisms due to the success of the species at the disturbed site and in botanical gardens.”

Numbers

At the time of its listing in 1994, the Service estimated the total population of Parish’s daisy at 16,000; we do not have recent estimates of the size of the population. The number of known occurrences of Parish’s daisy has increased since the Service listed the species. Any such increase likely reflects greater survey effort than an actual increase in abundance; differences in the manner in which surveyors define “occurrences” may have also contributed to the increase.

Distribution

Parish’s daisy occurs along an approximately 35-mile-long along area of carbonate substrates along the northern edge of the San Bernardino Mountains, north and east of Big Bear Lake, and east toward Joshua Tree National Park in San Bernardino County. The range and distribution of the species is essentially the same as it was at the time of listing.

Critical Habitat of Parish’s Daisy

The Service designated critical habitat for Parish’s daisy on December 24, 2002 (67 Federal 72

Register 78570). It occurs within a single unit of 4,420 acres along the northeastern slope of the San Bernardino Mountains.

Physical and Biological Features of Critical Habitat

The physical and biological features of critical habitat of Parish’s daisy are:

1. Soils derived primarily from upstream or upslope limestone, dolomite, or quartz monzonite parent materials that occur on dry, rocky hillsides, shallow drainages, or outwash plains at elevations between 3,842 and 6,400 feet;

2. Soils with intact, natural surfaces that have not been substantially altered by land use activities (e.g., graded, excavated, re-contoured, or otherwise altered by ground- disturbing equipment); and

3. Associated plant communities that have areas with an open canopy cover.

The Service (2015c) concluded that the Forest Service’s implementation of fuel reduction projects every 5 to 15 years in the San Bernardino National Forest was not likely to result in the destruction or adverse modification of critical habitat of Parish’s daisy. Thirty-four acres of critical habitat of this species occur in the Baldwin Lake treatment area. The Service reached its conclusion because of the small amount of critical habitat in the action area, the infrequent occurrence of the treatment activities, and proposed measures to protect critical habitat during treatments.

The Service (2017b) concluded that the proposed expansion of the Mitsubishi South Quarry was not likely to result in the destruction or adverse modification of critical habitat of Parish’s daisy. The expansion would result in the loss of 2.3 acres of critical habitat; this critical habitat contained the physical and biological features of critical habitat. To offset the loss of critical habitat, the mining company provided 144 acres of critical habitat that support the physical and biological features of the Parish’s daisy critical habitat, with the same protections we discussed for Cushenbury oxytheca.

CUSHENBURY MILK-VETCH

Unless otherwise noted, the information in this section is from the 5-year review for Cushenbury milk-vetch (Service 2009d).

Listing History

The Service listed the as threatened on August 24, 1994 (59 Federal Register 43652). The final listing rule notes that mining, energy development, and vehicle use threaten the species.

Species Biology and Life History 73

Cushenbury milk-vetch is a perennial plant in the pea family. It generally occurs on substrate derived from limestone, dolomite, or a mixture of limestone and dolomite. Its habitat includes rocky washes and gentle slopes within pinyon woodland, pinyon-juniper woodland, Joshua tree woodland, and blackbush scrub.

Recovery Plan

The Service has not completed a recovery plan for this species. Cushenbury milk-vetch is included in the draft recovery plan and habitat management strategy that we discussed previously in this document for Cushenbury oxytheca.

Five-Year Review

In our 5-year review, we determined that retaining the status of Cushenbury milk-vetch as endangered was appropriate. We reached this conclusion because a few, small, isolated populations represented the species and threats remained present. Since its listing, the Service has identified fire suppression and climate change as threats to Cushenbury milk-vetch.

The Service (2017b) concluded that the Forest Service’s approval of the expansion of the Mitsubishi South Quarry was not likely to jeopardize the continued existence of Cushenbury milk-vetch. The proposed action would result in the loss of 153.6 acres of suitable carbonate habitat and 0.16 acre of occupied habitat of Cushenbury milk-vetch. To offset these adverse effects, the mining company will contribute carbonate habitat lands to the reserve established through the management strategy “via quit-claim or title conveyance” to the Forest Service. The Forest Service would prohibit future mining claims or associated mining activities on 4 parcels, which support 96 known occurrences of Cushenbury milk-vetch on 175.8 acres.

Core Criteria for the Jeopardy Determination

Reproduction

We do not have information on the reproductive behavior of this species. The 5-year review states that “(p)ollinators are probably small bees.”

Numbers

The Service estimated the population size of Cushenbury milk-vetch to be between 5,000 and 10,000 individuals in fewer than 20 occurrences in its final listing rule. The Service later increased its estimate of the number of occurrences to 33 and the Forest Service has mapped 103 occurrences. As we have discussed previously in this biological opinion, these increases likely reflect differences in how surveyors define “occurrences,” rather than an increase in abundance.

Distribution

Cushenbury milk-vetch occurs on approximately 1,201 acres in scattered pockets along the 74

northern edge of the San Bernardino Mountains, north and east of Big Bear Lake, San Bernardino County.

Critical Habitat of the Cushenbury Milk-vetch

The Service designated critical habitat for Cushenbury milk-vetch on December 24, 2002 (67 Federal Register 78570). It occurs within a single unit of 4,365 acres along the northeastern slope of the San Bernardino Mountains.

The physical and biological features of critical habitat of Cushenbury milk-vetch are:

1. Soils derived primarily from the upper and middle members of the Bird Spring Formation and Undivided Cambrian parent materials that occur on dry flats and slopes or along rocky washes with limestone outwash/deposits at elevations between 3,864 and 6,604 feet;

2. Soils with intact, natural surfaces that have not been substantially altered by land use activities (e.g., graded, excavated, re-contoured, or otherwise altered by ground-disturbing equipment); and

3. Associated plant communities that have areas with an open canopy cover and little accumulation of organic material (e.g., leaf litter) on the surface of the soil.

CUSHENBURY BUCKWHEAT

Unless otherwise noted, the information in this section is from the 5-year review for Cushenbury buckwheat (Service 2009e).

Listing History

The Service listed the Cushenbury buckwheat as endangered on August 24, 1994 (59 Federal Register 43652). The final listing rule notes that mining, energy development, and vehicle use threaten the species.

Species Biology and Life History

Cushenbury buckwheat is a low, densely matted perennial plant in the buckwheat family. Its flowering stalks can reach up to 4 inches in height. It mainly occurs on gentle to steep slopes with north or west aspects within openings in pinyon woodland, pinyon-juniper woodland, Joshua tree woodland, and blackbush scrub between 4,600 and 7,900 feet in elevation on limestone or other carbonate substrates.

Recovery Plan

The Service has not completed a recovery plan for this species. Cushenbury buckwheat is included in the draft recovery plan and habitat management strategy that we discussed previously in this document for Cushenbury oxytheca. 75

Five-Year Review

In our 5-year review, we determined that retaining the status of Cushenbury buckwheat as endangered was appropriate. We reached this conclusion because a few, small, isolated populations represented the species and threats remained present. Since its listing, the Service has identified fire suppression and climate change as threats to Cushenbury milk-vetch.

The Service (2015c) concluded that the Forest Service’s implementation of fuel reduction projects every 5 to 15 years in the San Bernardino National Forest was not likely to jeopardize the continued existence of Cushenbury buckwheat. Individuals of this species occurs in the North Big Bear treatment area. The Service reached its conclusion because of the short duration of the treatment activities, their infrequent occurrence, and proposed measures to protect the species during treatments.

The Service (2017b) concluded that the Forest Service’s approval of the expansion of the Mitsubishi South Quarry was not likely to jeopardize the continued existence of Cushenbury buckwheat. The proposed action would result in the loss of 153.6 acres of suitable carbonate habitat and 33 acres of occupied habitat of Cushenbury buckwheat. To offset these adverse effects, the mining company will contribute carbonate habitat lands to the reserve established through the management strategy “via quit-claim or title conveyance” to the Forest Service. The Forest Service would prohibit future mining claims or associated mining activities on 4 parcels, which support 101 known occurrences of Cushenbury buckwheat on 112 acres.

Core Criteria for the Jeopardy Determination

Reproduction

Mistretta and White (2001 in Service 2009e) introduced Cushenbury buckwheat onto an irrigated, disturbed site in 1991 and 1992. Approximately 77 percent of the individuals survived to 1998. Because introduced individuals successfully reproduced, Mistretta and White (2001 in Service 2009e) suggested that “Cushenbury buckwheat was not dependent upon specialized pollinators or soil microorganisms due to the success of the species at the disturbed site and in botanical gardens.”

Numbers

At the time of listing, the Service estimated the abundance of Cushenbury buckwheat at 13,000 individuals within fewer than 20 occurrences. We do not have any information on population trends. The Forest Service later mapped 239 occurrences. As we have discussed previously in this biological opinion, these increases likely reflect differences in how surveyors define “occurrences,” rather than an increase in abundance.

Distribution

Cushenbury buckwheat occupies approximately 1,213 acres of habitat along the northern edge of 76

the San Bernardino Mountains in San Bernardino County.

Critical Habitat of Cushenbury Buckwheat

The Service designated critical habitat for Cushenbury buckwheat on December 24, 2002 (67 Federal Register 78570). It occurs within a single unit of 6,955 acres along the northeastern slope of the San Bernardino Mountains.

1. Soils derived primarily from the upper and middle members of the Bird Spring Formation and Bonanza King Formation parent materials that occur on hillsides at elevations between 4,600 and 7,900 feet;

2. Soils with intact, natural surfaces that have not been substantially altered by land use activities (e.g., graded, excavated, re-contoured, or otherwise altered by ground- disturbing equipment); and

3. Associated plant communities that have areas with an open canopy cover (generally less than 15 percent cover) and little accumulation of organic material (e.g., leaf litter) on the surface of the soil.

The Service (2015c) concluded that the Forest Service’s implementation of fuel reduction projects every 5 to 15 years in the San Bernardino National Forest was not likely to result in the destruction or adverse modification of critical habitat of Cushenbury buckwheat. Approximately 30 acres of critical habitat of this species occur in the North Big Bear treatment area. The Service reached its conclusion because of the small amount of critical habitat in the action area, the infrequent occurrence of the treatment activities, and proposed measures to protect critical habitat during treatments.

The Service (2017b) concluded that the Forest Service’s approval of the expansion of the Mitsubishi South Quarry was not likely to result in the destruction or adverse modification of critical habitat of Cushenbury buckwheat. The proposed action would result in the loss of 114 acres of critical habitat of Cushenbury buckwheat. To offset the loss of critical habitat, the mining company will contribute carbonate habitat lands to the reserve established through the management strategy “via quit-claim or title conveyance” to the Forest Service. The Forest Service would prohibit future mining claims or associated mining activities on 4 parcels, which support 340 acres that support the physical and biological features of critical habitat of Cushenbury buckwheat.

LANE MOUNTAIN MILK-VETCH

Unless otherwise noted, the following information is from the 5-year review (Service 2008).

Listing History

The Service listed Lane Mountain milk-vetch as endangered on October 6, 1998 (63 Federal 77

Register 53596). The primary threats to Lane Mountain milk-vetch were surface mining, off- highway vehicle recreation, non-native species, and military training activities.

Species Biology and Life History

Lane Mountain milk-vetch is a perennial plant in the pea family. It typically twines up through a host shrub that it uses for structural support. Although the taproot is perennial, the above-ground portion of the plant is herbaceous; it re-sprouts from the taproot or old stems with the first winter rains and dies back during the drier summer months. Plants may remain dormant during years of low rainfall.

Recovery Plan

The Service has not completed a recovery plan for this species.

Five-Year Review

In our 5-year review, we recommended downlisting Lane Mountain milk-vetch to threatened status. We reached this conclusion because:

1. At the time of listing, we were aware of few individuals within four occurrences. Intensive surveys by the U.S. Army in 2001 revealed that two of those four occurrence were actually a single larger occurrence. The surveys also detected a fourth occurrence and more than 5,700 individuals.

2. Monitoring indicated the numbers of adult and newly recruited individuals have been decreasing since 1999;

3. The U.S. Army would begin training on approximately 23 percent of the population but most of the rest of the known habitat was in conservation management; and

4. Its life history species includes episodic germination events that seem to be tied to medium- and large-scale weather patterns and patch die-offs have been observed, a high level of uncertainty exists regarding the ability of Lane Mountain milk-vetch to persist through local extirpations and recolonization of suitable habitat. ]

We concluded that the new information regarding the species’ more widespread distribution and greater numbers of individual and the placement of approximately 78 percent of the areal extent of the population into conservation management met the definition of a threatened species.

Core Criteria for the Jeopardy Determination

Reproduction

In the wild, seed production is low, even in years of abundant rainfall. Seed production was much greater under favorable greenhouse conditions; consequently, harsh weather and predation 78

on seeds may limit reproduction in the wild.

Six insect taxa were observed on Lane Mountain milk-vetch during two studies on its pollination ecology; some were likely robbing nectar and were uninvolved with pollination. Leaf-cutter and metal leaf-cutter bees (Anthidium dammersi, A. emarginatum, and Osmia latisculata) were the most abundant visitors and likely effective pollinators.

Numbers

In 2001, surveys detected 5,723 individuals in the 4 occurrences. Researchers from the University of California monitored 2 occurrences from 1999 to 2006 and observed a 77 percent decline in the number of individuals within their study plots. Given the number of years with low rainfall between 2006 and the present, we expect that trend is likely to have continued.

Distribution

Four populations of Lane Mountain milk-vetch occur in the western Mojave Desert, north of the city of Barstow. The 4 areas cover approximately 21,400 acres.

Critical Habitat of the Lane Mountain Milk-vetch

The Service designated 14,069 acres of critical habitat for Lane Mountain milk-vetch on May 19, 2011 (76 Federal Register 29108). The critical habitat comprises the Coolgardie Mesa and Paradise critical habitat units; these units cover approximately 13,105 and 964 acres, respectively. Because the U.S. Army was implementing an integrated natural resources management plan on its lands within Fort Irwin, the Service exempted habitat from designation within the National Training Center under section 4(a)(3)(B) of the Endangered Species Act.

The physical and biological features of critical habitat of Lane Mountain milk-vetch are:

1. Shallow soils at elevations between 3,100 and 4,200 feet derived primarily from Jurassic or Cretaceous granitic bedrock, and less frequently on soils derived from diorite or gabbroid bedrock, or on granitic soils overlain by scattered rhyolitic cobble, gravel, and sand.

2. Host shrubs at elevations between 3,100 and 4,200 feet. The primary host shrubs include but are not limited to: turpentine bush (Thamnosma montana), burro bush, California buckwheat (Eriogonum fasciculatum ssp. polifolium), golden bush (Ericameria cooperi var. cooperi), Mormon tea (Ephedra nevadensis), and paperbag bush (Salazaria mexicana) that are usually found in mixed desert-shrub communities.

ENVIRONMENTAL BASELINE

We have included the best available information regarding the status of the plant species in the action area in the following sections. The areas occupied by these species are small compared to 79

that of the desert tortoise and do not experience as much human activity. For those reasons and because researchers have worked far less with these species and their critical habitat, we do not have extensive information regarding their status.

Previous Consultations in the Action Area

We have discussed consultations that addressed land use planning in the Consultation History section of this biological opinion.

Triple-ribbed Milk-vetch

The action area supports approximately 211 acres of triple-ribbed milk-vetch in the Sand to Snow National Monument (Bureau 2019b, Table 3.4-4). Within the action area, most of the occurrences and potential habitat are located in the San Gorgonio Wilderness and Big Morongo Area of Critical Environmental Concern (Service 2009a). The Bureau prohibits vehicular travel in the former area, although it contains hiking trails; the latter area supports few routes of travel.

Table 3.4-4 (Bureau 2019b) includes acreages only on lands managed by the Bureau. The action area likely supports additional habitat and occurrences of most of the listed plant species discussed in this biological opinion.

Cushenbury Oxytheca

Cushenbury oxytheca occurs at three locations within the action area; two occurrences are on Bureau lands and the other is in an area of “private and/or BLM management” (Bureau 2019b, Table 3.4-4, also page 3-30). The occurrences are within the Bureau’s Carbonate Endemic Plants Research Natural Area and California Desert National Conservation Lands (Bureau 2016, Appendix B). The management objective for the research natural area is to “[m]aintain or improve condition of habitat for the sensitive plant species.” The occurrences are within Rattlesnake Canyon Allotment (cattle).

Critical Habitat of Cushenbury Oxytheca

The action area supports approximately 83 acres of critical habitat for this species (Bureau 2019b Table 3.4-4).

Parish’s Daisy

The action area supports approximately 52 acres of habitat for Parish’s daisy in the Juniper Flats area and approximately 288 acres in the Rattlesnake Canyon area (Bureau 2019b, Table 3.4-4).

Critical Habitat of Parish’s Daisy

The action area includes approximately 64 acres of critical habitat in the Juniper Flats area and approximately 881 acres of critical habitat in the Rattlesnake Canyon area (Bureau 2019b, Table 80

3.4-4).

CUSHENBURY MILK-VETCH

Botanists have found five occurrences within the planning area since 1990 (Bureau 2019b, page 3-29). The Bureau (2019b, Table 3.4-4) estimates that these occurrences are located within approximately 154 acres in the Carbonate Endemic Plants Research Natural Area. The management objective for the research natural area is to “[m]aintain or improve condition of habitat for the sensitive plant species.”

Critical Habitat of the Cushenbury Milk-vetch

The action area includes approximately 8 acres of critical habitat in the Juniper Flats Subregion and approximately 830 acres of critical habitat in the Rattlesnake Canyon Subregion (Bureau 2019b, Table 3.4-4).

Cushenbury Buckwheat

Approximately 1,184 acres of “element occurrences” of Cushenbury buckwheat habitat are included in the planning area (Bureau 2019b, page 3-29). Table 3.4-4 (Bureau 2019b) indicates that approximately 32 acres lie with the Juniper Flats Subregion and approximately 733 acres occur within the Rattlesnake Canyon Subregion. The plants in the Rattlesnake Canyon Subregion are within the Carbonate Endemic Plants Research Natural Area; the management objective for this area is to “(m)aintain or improve condition of habitat for the sensitive plant species.”

Critical Habitat of Cushenbury Buckwheat

Approximately 420 acres of critical habitat occur within the planning area, with approximately 32 acres in the Juniper Flats Subregion and approximately 390 acres in the Rattlesnake Canyon Subregion (Bureau 2019b, Table 3.4-4).

LANE MOUNTAIN MILK-VETCH

The action area supports approximately 2,004 acres of “element occurrences” of Lane Mountain milk-vetch on public lands within the Coolgardie Subregion (Bureau 2019b, Table 3.4-4).

Critical Habitat of the Lane Mountain Milk-vetch

Both critical habitat units of Lane Mountain milk-vetch occur within the Coolgardie Subregion (76 Federal Register 29108). Approximately 9,897 acres of critical habitat of Lane Mountain milk-vetch critical habitat are located on public lands (Bureau 2019b, Table 3.4-4); the Bureau has an active program to manage off-highway vehicle use in the Coolgardie Critical Habitat Unit. The Army manages approximately 318 and 964 acres for conservation of Lane Mountain milk-vetch in the Paradise and Coolgardie critical habitat units, respectively (76 Federal Register 29108). 81

EFFECTS ON LISTED PLANTS AND THEIR CRITICAL HABITAT

General Discussion of the Effects of Off-highway Vehicle Use on the Listed Plants

The final supplemental environmental impact statement (Bureau 2019b, section 4.4.1.2) summarizes the effects of off-highway vehicle use on plants. Off-highway vehicles can:

1. Reduce the area occupied by plants when a new road or staging area forms;

2. Alter percolation of rain and surface flow;

3. Increase the biomass of plants adjacent to roads because they can receive additional water;

4. Provide a corridor for dispersal of some species of non-native plants;

5. Change fire ecology because of increased presence of non-native species;

6. Increase the occurrence of fires started by visitors; and

7. Cause fugitive dust.

We consider this list to include those effects that are reasonably certain to occur and will base our analysis on these effects. We will first evaluate how these potential effects of off-highway vehicle use may affect listed plants in a general manner in relation to the proposed implementation-level actions. We will then evaluate the potential effects with regard to the specific taxa. We will then repeat the process for critical habitat.

We acknowledge that hikers, equestrians, and non-motorized vehicles will also use at least some of the routes in the action area. These uses would generally have the same effect as off-highway vehicles, albeit to a lesser degree. Exceptions to this statement are that hikers may pick flowers and horses may consume parts of listed plant species; however, we consider these effects insignificant. Consequently, we will focus our discussion on off-highway vehicle use with the assumption that any effects of hiking and equestrian use and non-motorized vehicles would comprise a minor component of the overall effect of the proposed action.

Some users of Bureau lands in the action area are reasonably certain to abuse the route network to engage in unauthorized activities, such as stopping, parking, and camping outside of previously disturbed areas, driving cross-country, and dumping trash. These unauthorized activities could destroy individuals of the listed plant species; many of these activities are likely to cause the same impacts that we will discuss with regard to authorized activities in this section of the biological opinion. An additional impact would be the creation of new transportation linear disturbances. 82

We cannot predict the extent of these unauthorized activities. In general, we expect that most unauthorized activities are likely to be small in scale. Unauthorized activities are less likely to affect the listed carbonate plants because the steep terrain discourages extensive use. A large portion of the range of triple-ribbed milk-vetch in the action area is within the San Gorgonio Wilderness Area; its location is likely to protect it from unauthorized activities there. Given the more level terrain in which it occurs, Lane Mountain milk-vetch is more susceptible to the effects of unauthorized use; however, the Bureau is aware of the challenges in that area and will continue to monitor and manage use there.

Plan Amendment I

The proposed action with regard to this plan amendment and its implementation-level decisions comprises the designation of 5,997 miles of off-highway vehicle open and limited routes and 230 miles of routes that are closed to off-highway vehicles but open to non-motorized or non- mechanized use . The Bureau’s proposed action would not result in the creation of new routes. The Bureau has proposed to designate as open some portions of existing routes that it had not previously considered open. Therefore, the proposed action would not reduce the area occupied by plants through the development of new roads or staging areas.

Because the Bureau would reclaim, restore, or rehabilitate transportation linear disturbances, we expect that the proposed action would result in a decrease in the degree to which existing disturbed areas alter the percolation of rain and surface flow. We cannot predict the extent to which reclamation, restoration, or rehabilitation would affect percolation of rain and surface flow, because the type of substrate, previous level of use, and the amount of previous disturbance would vary.

The proposed action would not increase the biomass of plants growing adjacent to routes because the Bureau is not creating new routes. The reclamation, restoration, or rehabilitation of transportation linear disturbances is likely to reduce the abundance of non-native plants along these areas over time. The variables we discussed in the previous paragraph would also be factors with regard to plant biomass.

The reclamation, restoration, or rehabilitation of transportation linear disturbances and the accompanying reduction in increased biomass along their edges would result in fewer opportunities for dispersal of some species of non-native plants.

A decrease in the areas where plant biomass is elevated and non-native plants are common would reduce the likelihood of human-caused wildfires.

The reclamation, restoration, or rehabilitation of a transportation linear disturbance would return, over time, the level of dust generated from that area to its natural condition; the amount of time over which restoration would occur would vary, depending upon the condition of the disturbance and the type of substrate. We cannot predict the extent to which the decrease in generated dust would affect individuals of the listed plant species, because the type of substrate and previous level of disturbance would vary among sites. 83

The final supplemental environmental impact statement (Bureau 2019b, page 4-60) notes that “(f)ugitive dust can settle on plant foliage, resulting in reducing plant growth rates, size, and survivorship.” Wijayratne et al. (2004 in Service 2008b) found that, with Lane Mountain milk- vetch, “applications of dust did not affect leaf growth and photosynthesis increased; however, shoot length decreased.” They hypothesized that “heavily dusted plants compensate by putting more effort into new leaves and reducing the availability of resources for shoot growth.” Consequently, we cannot predict how dust would affect individuals of the listed plant species; however, in addition to the variables discussed in the previous paragraph, the distance of the plant from the road would also factor into the overall effect. That is, the farther a plant is from the source of the dust, the less likely it is to undergo a measurable effect. Given the overall low density of open and limited routes near individuals of the listed plant species, we expect that dust from open and limited routes is unlikely to cause a measurable effect.

Plan Amendment III

The proposed action with regard to this plan amendment and its implementation-level decisions comprises the designation of “C” routes between the Spangler Hills Off-highway Vehicle Recreation Area and the city of Ridgecrest and a speed-controlled route-connector route between the Johnson Valley and Stoddard Valley Off-highway Vehicle Recreation Areas. The listed plant species and their critical habitat do not occur in these areas. Consequently, this implementation- level decision will not affect the listed plant species or their critical habitat; we will not discuss this Plan Amendment again with regard to these species and their critical habitat.

Plan Amendment IV

Under this implementation-level decision, the Bureau will add Koehn, Cuddeback, Coyote, and Chisholm Trail dry lakes to the list of designated lakebeds. The listed plant species and their critical habitat do not occur within or adjacent to these dry lakes. Consequently, this implementation-level decision will not affect the listed plant species or their critical habitat; we will not discuss this Plan Amendment again with regard to these species and their critical habitat.

Plan Amendment VI

The proposed action with regard to this plan amendment and its implementation-level decisions comprises the limitation of stopping, parking, and camping to previously disturbed areas within 50 feet of the route centerline inside areas of critical environmental concern for the desert tortoise and California Desert National Conservation Lands. Outside of these areas, the Bureau proposes to limit stopping and parking to previously disturbed areas within 100 feet of the route centerline. The Bureau also proposes to limit stopping, parking, and camping to designated areas outside of 50- and 100-foot areas that are already disturbed.

The Bureau’s proposed action would generally not result in the creation of new stopping and parking areas. Currently, visitors may stop and park their vehicles up to 300 feet from the centerline of a route outside of areas of critical environmental concern for the desert tortoise and California Desert National Conservation Lands. 84

Lane Mountain milk-vetch is located entirely within areas of critical environmental concern for the desert tortoise and California Desert National Conservation Lands. We are aware of Lane Mountain milk-vetch growing within 50 feet of routes. Because the Bureau will further limit stopping and parking to previously disturbed areas, which generally do not support its host shrubs, this proposed change in management direction would benefit Lane Mountain milk-vetch.

Most known occurrences of the carbonate plants and triple-ribbed milk-vetch on public lands are California Desert National Conservation Lands; the Bureau’s proposed management direction would also benefit these species in the same manner we described for Lane Mountain milk- vetch. Because a few occurrences lie outside of California Desert National Conservation Lands, the reduction in the area available for stopping and parking to previously disturbed areas within 100 feet from the centerline of the route will also benefit these individuals. Finally, most of the occurrences of the carbonate plants are in areas the “terrain generally prevents off-road travel, and use of these roads is infrequent” (Bureau 2019b, page 4-68).

Because the Bureau has designated as open some routes that were formerly unauthorized, it has increased to a small degree the area where stopping and camping may occur. This increase in area does not necessarily indicate an increase in disturbance to the listed plant species because the Bureau will allow stopping and camping only in previously disturbed areas where the plants are either absent or in low numbers.

We expect that the remaining general effects of off-highway vehicle use that we have discussed previously would also decrease because the proposed action with regard to stopping, parking, and camping would reduce the loss of individual plants to areas where they are likely present in low numbers, if at all. The rehabilitation of transportation linear disturbances should also reduce the exposure of the listed plant species to the other potential adverse effects.

Implementation of the Travel and Transportation Program

The Bureau will implement the travel and transportation program within a framework of adaptive management. Acquisition and disposal of lands, changing uses, and changing technology will require that the Bureau continually re-evaluate the travel and transportation network; see the “Maintaining the Transportation Network” section of Appendix G (Bureau 2019b). When monitoring and re-evaluation indicate that use of the travel and transportation network or other changing circumstances are affecting the listed plant species, the Bureau will employ the appropriate minimization and mitigation actions for rare and special status plant species listed in Table G-2 (Bureau 2019b). These actions include, but are not limited to, restricting stopping, parking, and camping, adding parking and camping areas to control disturbance, installing and maintaining barriers, modifying access, and rout closure. The intended purpose of these actions is to reduce adverse effects on the listed plant species and its habitat. The Bureau’s strategy with the implementation of these actions is to start with the “least tool” to achieve the goal of resource protection; it will use more aggressive actions, including closure of routes, as needed. 85

We do not know the future specific issues that the Bureau would need to address as part of the management of the travel and transportation network. However, during implementation, we expect that these issues would involve minor and localized effects to listed plant species and minor ground disturbance associated with managing the travel network (e.g., installation of road signs and kiosks, etc.) that are generally similar to those that we have discussed previously in this section. If implementation of the minimization and mitigation actions would result in ground disturbance (and therefore disturbance of the listed plant species and their habitat), the Bureau will apply the appropriate conservation and management actions from its land use plan to protect the listed plants. Consequently, the Bureau’s implementation of the travel and transportation program is unlikely to affect the listed plant species in a measurable manner.

We will now consider the overall effects of the Bureau’s proposed action on each of the listed plant species. For each species, we have considered the amount of exposure to the adverse effect of routes that the species is likely to receive under the proposed action in relation to the reproduction, numbers, distribution, and recovery of the species.

The following comments apply to all the tables in this section of the biological opinion; footnotes to individual tables apply only to those tables.

 The numbers for all features are for Bureau lands only.

 The “acres of occurrence” remains constant across all alternatives because this number reflects the size of the occurrence on Bureau lands.

 All other tables are from the errata (Toedtli 2019).

 Using tables 3.4-4 (Bureau 2109b), 4.4-3, and 4.4-15 (Toedtli 2019), the Bureau calculated acreage and mileage using the California Natural Diversity Database’s buffers. “California Natural Diversity Database’s buffers” refers to the manner in which the California Department of Fish and Wildlife manages its GIS data. That is, depending on the “accuracy level” of the record, the California Natural Diversity Database may buffer an occurrence by different distances. The Bureau (2019b) also noted that the “inclusion of multiple data layers from the California Natural Diversity Database’s GIS likely results in an overestimate, which is a conservative approach with respect to acres potentially affected for some of plant species.” The key point is that the “acres of occurrence” most likely does not indicate the actual acreage occupied by the occurrence. 86

Triple-ribbed Milk-vetch

Table 13. Effects of the proposed action on triple-ribbed milk-vetch.

Triple-ribbed Milk-vetch Quantity1 Table1,2 Acres of occurrence 210.8 3.4-4 Miles of OHV open and (4.4-3) 4.4-15 limited, non-mechanized, (0.4) 0.4 and non-motorized Miles of transportation linear disturbance (0.2) 0.2 Acres of stopping, parking, and camping (9.5) 5.2 1 The numbers in parentheses are for the no action alternative (alternative 1); the remaining numbers are for the proposed action (alternative 5). 2 All information is from the errata to the final supplemental environmental impact statement (Toedtli 2019), except for Table 3.4-4, which is from the final supplemental environmental impact statement (Bureau 2019b).

Compared to the no action alternative, the Bureau is not proposing to designate any additional mileage of routes as open. Because of the change in the stopping, parking, and camping allowances, less acreage of occurrence (5.2 instead of 9.5) is available for those activities. Because this use would be restricted to previously disturbed areas, the potential to disturb triple- ribbed milk-vetch is minimal.

The following paragraphs address the metrics for determining whether a proposed action is likely to jeopardize the continued existence of a species, based on the best available information. Unless cited specifically in these paragraphs, we are summarizing general information about the effects of routes on plants from the General Discussion of the Effects of Off-highway Vehicle Use on Plants” section of this biological opinion.

Reproduction

Based on the best available information, the proposed action is unlikely to have measurable effects on the reproduction of triple-ribbed milk-vetch. We acknowledge that dust generated by vehicles may have some effect on individual plants but this effect diminishes with distance from the route and only a small portion of the plant’s occurrence are in proximity to routes. That is, only 0.4 mile of open route is within the buffered distance of a triple-ribbed milk-vetch occurrence. Most occurrences in the action area are located in the San Gorgonio Wilderness, which is closed to vehicle use.

Numbers

We do not have information regarding the number of plants in the action area. The number of plants visible above ground varies from year to year, based on growing conditions. The proposed action is unlikely to affect many individuals of triple-ribbed milk-vetch because most plants are 87

located in the San Gorgonio Wilderness. Additionally, this species grows in rugged terrain; therefore, outside of the wilderness area, their locations are not readily available for vehicle use. For these reasons, because we do not expect numerous plants to grow in previously disturbed areas and because, under the proposed action, only 0.4 mile of open route is within the buffered distance of a triple-ribbed milk-vetch occurrence, we anticipate that the proposed action is unlikely to have a measurable effect on the number of triple-ribbed milk-vetch.

Distribution

The proposed action will not alter the distribution of triple-ribbed milk-vetch because it is unlikely to result in the loss of habitat.

Recovery

The proposed action is unlikely to adversely affect recovery of triple-ribbed milk-vetch. By limiting stopping, parking, and camping to previously disturbed areas along designated routes and by implementing a program to monitor off-highway vehicle use and rehabilitate transportation linear disturbances, the Bureau is furthering the recovery of this species.

CONCLUSION

After reviewing its current status, the environmental baseline for the action area, the effects of the proposed action, and the cumulative effects, we have determined that the activities considered in this biological opinion are not likely to jeopardize the continued existence of triple- ribbed milk-vetch. We reached this conclusion because:

1. The Bureau is not proposing to develop any new routes through known occurrences of this species;

2. The Bureau will allow stopping, parking, and camping only in previously disturbed areas, which are unlikely to support individuals of this species; and

3. Most occurrences of the species reside in the San Gorgonio Wilderness Area, which is off-limits to vehicular travel. 88

Cushenbury Oxytheca

Table 14. Effects of the proposed action on Cushenbury oxytheca.

Cushenbury Oxytheca Quantity1 Table1,2 Acres of occurrence 83.2 3.4-4 Miles of OHV open and limited, non-mechanized, and non-motorized (0) 0 Miles of transportation linear (4.4-3) 4.4-15 disturbance (0) 0 Acres of stopping, parking, (0) 0 and camping 1 The numbers in parentheses are for the no action alternative (alternative 1); the remaining numbers are for the proposed action (alternative 5). 2 All information is from the errata to the final supplemental environmental impact statement (Toedtli 2019), except for Table 3.4-4, which is from the final supplemental environmental impact statement (Bureau 2019b).

No known occurrences of Cushenbury oxytheca overlap with designated routes of transportation linear disturbances on lands managed by the Bureau. Some potential exists that surveys will detect new occurrences along designated routes in the future.

The following paragraphs address these potential effects with regard to the metrics for determining whether a proposed action is likely to jeopardize the continued existence of a species. Unless cited specifically in these paragraphs, we are summarizing general information about the effects of routes on plants from the General Discussion of the Effects of Off-highway Vehicle Use on Plants” section of this biological opinion.

Reproduction

Based on the best available information, the proposed action is unlikely to measurably affect the reproduction of Cushenbury oxytheca because individuals are not located adjacent to designated routes and this effect diminishes with distance from the route. If surveyors detect additional occurrences along designated routes in the future, we expect that these occurrences would comprise few individuals; otherwise, their detections would have occurred previously. The effects of dust on a few individuals would not measurably affect reproduction of Cushenbury oxytheca as a species.

Numbers

No individuals of Cushenbury oxytheca overlap with designated routes in the action area. Consequently, the proposed action is unlikely to affect the number of individuals of Cushenbury oxytheca. As we discussed in the previous paragraph, a few undetected individuals may be present along designated routes. If off-highway vehicle use affected these plants, the overall effect on the species would be negligible because of the likely small number of individuals likely to be present. 89

Distribution

The proposed action is unlikely to disturb any habitat of Cushenbury oxytheca. Therefore, it will not alter the distribution of the species.

Recovery

The proposed action is unlikely to adversely affect recovery of Cushenbury oxytheca because designated routes do not overlap any known occurrences of the species. The Bureau’s monitoring of off-highway vehicle use and rehabilitation of transportation linear disturbances will ensure that recovery of Cushenbury oxytheca is not impaired.

CONCLUSION

After reviewing its current status, the environmental baseline for the action area, the effects of the proposed action, and the cumulative effects, we have determined activities considered in this biological opinion are not likely to jeopardize the continued existence of Cushenbury oxytheca. We reached this conclusion because the Bureau is not proposing to develop any new routes through known occurrences of this species.

Parish’s Daisy

Table 15. Effects of the proposed action on Parish’s daisy.

Parish’s Daisy Quantity1 Table1,s Acres of occurrence 340 3.4-4 Miles of OHV open and limited, non-mechanized, and (1.9) 1.4 non-motorized Miles of transportation linear (4.4-3) 4.4-15 (0.8) 1.3 disturbance Acres of stopping, parking, and camping (40.4) 20.9 1 The numbers in parentheses are for the no action alternative (alternative 1); the remaining numbers are for the proposed action (alternative 5). 2 All information is from the errata to the final supplemental environmental impact statement (Toedtli 2019), except for Table 3.4-4, which is from the final supplemental environmental impact statement (Bureau 2019b).

Compared to the no action alternative, the Bureau is proposing to designate 0.5 mile less of route as open. Consequently, less acreage of occurrence (20.9 instead of 40.4) is available for stopping, parking, and camping. Because this use would be restricted to previously disturbed areas, the potential to crush Parish’s daisy is minimal.

The following paragraphs address these potential effects with regard to the metrics for determining whether a proposed action is likely to jeopardize the continued existence of a species. Unless cited specifically in these paragraphs, we are summarizing general information 90

about the effects of routes on plants from the General Discussion of the Effects of Off-highway Vehicle Use on Plants” section of this biological opinion.

Reproduction

Based on the best available information, the proposed action is unlikely to have measurable effects on the reproduction of Parish’s daisy. Dust generated by vehicles may have affect individual plants but this effect diminishes with distance from the route and the Bureau’s proposed action would reduce the portion of the plant’s occurrence that is in proximity to routes.

Numbers

We do not have information regarding the number of individuals of Parish’s daisy in the action area. We expect that few individuals occur with the designated routes and in previously disturbed areas within 50 feet of the route’s centerline. Because the Bureau proposes to limit vehicle use to previously disturbed areas (i.e., designated routes and previously disturbed areas adjacent to the routes), we expect that off-highway vehicle use is likely to affect few plants. For this reason, we anticipate that the proposed action is unlikely to have a measurable effect on the number of Parish’s daisies.

Distribution

The proposed action will not alter the distribution of Parish’s daisy because it is likely to result in the loss of a negligible amount of habitat, if any.

Recovery

The proposed action is unlikely to adversely affect recovery of Parish’s daisy. By limiting stopping, parking, and camping to previously disturbed areas along designated routes and by implementing a program to monitor off-highway vehicle use and rehabilitate transportation linear disturbances, the Bureau is furthering the recovery of this species.

CONCLUSION

After reviewing its current status, the environmental baseline for the action area, the effects of the proposed action, and the cumulative effects, we have determined that the activities considered in this biological opinion are not likely to jeopardize the continued existence of Parish’s daisy. We reached this conclusion because:

1. The Bureau is not proposing to develop any new routes through known occurrences of Parish’s daisy and has decreased the area likely to be disturbed by designated routes; and

2. The Bureau will allow stopping, parking, and camping only in previously disturbed areas, which are unlikely to support individuals of this species. 91

Cushenbury Milk-vetch

Table 16. Effects of the proposed action on Cushenbury milk-vetch.

Cushenbury Milk-vetch Quantity1 Table1,2 Acres of occurrence 157.83 3.4-4 Miles of OHV open and (4.4-3) 4.4-15 limited, non-mechanized, and (0.7) 0.7 non-motorized Miles of transportation linear (0.4) 0.4 disturbance Acres of stopping, parking, (12.4) 9.4 and camping 1 The numbers in parentheses are for the no action alternative (alternative 1); the remaining numbers are for the proposed action (alternative 5). 2 All information is from the errata to the final supplemental environmental impact statement (Toedtli 2019), except for Table 3.4-4, which is from the final supplemental environmental impact statement (Bureau 2019b). 3 The Bureau (2019b) combined the acreage of the amount of critical habitat for this species with the acreages of the occurrences from Table 3.4-4; because Cushenbury milk-vetch is not likely to occupy all critical habitat, we did not use the critical habitat acreage in this table.

The no action and proposed alternatives would result in the same general effects to Cushenbury milk-vetch with less acreage of occurrence (9.4 instead of 12.4) available for stopping, parking, and camping. Because these effects would be restricted to previously disturbed areas, the potential to disturb Cushenbury milk-vetch is minimal.

Reproduction

Based on the best available information, the proposed action is unlikely to have measurable effects on the reproduction of Cushenbury milk-vetch. Dust generated by vehicles may have some effect on individual plants but this effect diminishes with distance from the route and only a small portion of the plant’s occurrences (i.e., approximately 0.7 mile) is in proximity to open routes.

Numbers

We do not have information regarding the number of Cushenbury milk-vetch in the action area. We expect that few, if any, individuals occur within the designated routes and in previously disturbed areas adjacent to the route. Because the Bureau proposes to limit vehicle use to these previously disturbed areas, off-highway vehicle use is likely to affect few plants. For this reason, we anticipate that the proposed action is unlikely to have a measurable effect on the number of Cushenbury milk-vetch. 92

Distribution

The proposed action will not alter the distribution of Cushenbury milk-vetch because it is likely to result in the loss of a negligible amount of habitat, if any.

Recovery

The proposed action is unlikely to adversely affect recovery of Cushenbury milk-vetch. By limiting stopping, parking, and camping to previously disturbed areas along designated routes and by implementing a program to monitor off-highway vehicle use and rehabilitate transportation linear disturbances, the Bureau is furthering the recovery of this species.

CONCLUSION

After reviewing its current status, the environmental baseline for the action area, the effects of the proposed action, and the cumulative effects, we have determined that the activities considered in this biological opinion are not likely to jeopardize the continued existence of Cushenbury milk-vetch. We reached this conclusion because:

1. The Bureau is not proposing to develop any new routes through known occurrences of this species; and

2. The Bureau will allow stopping, parking, and camping only in previously disturbed areas, which are unlikely to support individuals of this species.

Cushenbury Buckwheat

Table 17. Effects of the proposed action on Cushenbury buckwheat.

Cushenbury Buckwheat Quantity1 Table1,2 Acres of occurrence 764.43 3.4-4 Miles of OHV open and (4.4-3) 4.4-15 limited, non-mechanized, and (1.2) 1.2 non-motorized Miles of transportation linear (0.5) 0.5 disturbance Acres of stopping, parking, (31.1) 18.3 and camping 1 The numbers in parentheses are for the no action alternative (alternative 1); the remaining numbers are for the proposed action (alternative 5). 2 All information is from the errata to the final supplemental environmental impact statement (Toedtli 2019), except for Table 3.4-4, which is from the final supplemental environmental impact statement (Bureau 2019b). 3 The Bureau (2019b) combined the acreage of the amount of critical habitat for this species with the acreages of the occurrences from Table 3.4-4; because Cushenbury buckwheat is not likely to occupy all critical habitat, we did not use the critical habitat acreage in this table. 93

The proposed alternative would reduce the area of Cushenbury buckwheat occurrence that might experience stopping, parking, and camping (18.3 instead of 31.1 acres). Because these effects would be restricted to previously disturbed areas where the species is less likely to grow, the potential to disturb Cushenbury buckwheat is minimal.

Reproduction

Based on the best available information, the proposed action is unlikely to have measurable effects on the reproduction of Cushenbury buckwheat. Dust generated by vehicles may have some effect on individual plants but this effect diminishes with distance from the route and only a small portion of the plant’s occurrence are in proximity to routes.

Numbers

We do not have information regarding the number of Cushenbury buckwheat in the action area. We expect that few individuals occur with the designated routes and in previously disturbed areas adjacent to the route. Because the Bureau proposes to limit vehicle use to these previously disturbed areas, off-highway vehicle use is likely to affect few plants. For this reason, we anticipate that the proposed action is unlikely to have a measurable effect on the number of Cushenbury buckwheat.

Distribution

The proposed action will not alter the distribution of Cushenbury buckwheat because it is likely to result in the loss of a negligible amount of habitat, if any.

Recovery

The proposed action is unlikely to adversely affect recovery of Cushenbury buckwheat. By limiting stopping, parking, and camping to previously disturbed areas along designated routes and by implementing a program to monitor off-highway vehicle use and rehabilitate transportation linear disturbances, the Bureau is furthering the recovery of this species.

CONCLUSION

After reviewing its current status, the environmental baseline for the action area, the effects of the proposed action, and the cumulative effects, we have determined that the activities considered in this biological opinion are not likely to jeopardize the continued existence of Cushenbury buckwheat. We reached this conclusion because:

1. The Bureau is not proposing to develop any new routes through known occurrences of this species; and

2. The Bureau will allow stopping, parking, and camping only in previously disturbed areas, which are unlikely to support individuals of this species. 94

Lane Mountain Milk-vetch

Table 18. Effects of the proposed action on Lane Mountain milk-vetch.

Lane Mountain Milk-vetch Quantity1 Table1,2 Acres of occurrence 2,005.6 3.4-4 Miles of OHV open and (4.4-3) 4.4-15 limited, non-mechanized, and (5.5) 5.4 non-motorized Miles of transportation linear (10.8) 10.9 disturbance Acres of stopping, parking, (119.2) 72.9 and camping 1 The numbers in parentheses are for the no action alternative (alternative 1); the remaining numbers are for the proposed action (alternative 5). 2 All information is from the errata to the final supplemental environmental impact statement (Toedtli 2019), except for Table 3.4-4, which is from the final supplemental environmental impact statement (Bureau 2019b).

The Bureau is proposing to designate slightly less open routes through alternative 5. The most substantial change with regard to the proposed action is that allowing stopping, parking, and camping only in previously disturbed areas would reduce the potential for off-highway vehicles to damage Lane Mountain milk-vetch (72.9 instead of 119.2 acres). In general, Lane Mountain milk-vetch occurs in areas where shrubs form relatively dense cover; previously disturbed areas are distinctly visible and do not support the shrubs in which Lane Mountain milk-vetch usually grows.

Reproduction

Based on the best available information, the proposed action is unlikely to have measurable effects on the reproduction of Lane Mountain milk-vetch. We acknowledge that dust generated by vehicles may have some effect on individual plants but this effect diminishes with distance from the route.

Numbers

Individuals of Lane Mountain milk-vetch predominantly grow within other species of shrubs and shrubs do not grow in the previously disturbed areas to which the Bureau would limit vehicle use. Therefore, we anticipate that the proposed action is unlikely to affect the number of Lane Mountain milk-vetch.

Distribution

The proposed action will not alter the distribution of Lane Mountain milk-vetch because it is likely to result in the loss of a negligible amount of habitat, if any. 95

Recovery

The proposed action is unlikely to adversely affect recovery of Lane Mountain milk-vetch. By limiting stopping, parking, and camping to previously disturbed areas along designated routes and by implementing a program to monitor off-highway vehicle use and rehabilitate transportation linear disturbances, the Bureau is furthering the recovery of this species.

CONCLUSION

After reviewing its current status, the environmental baseline for the action area, the effects of the proposed action, and the cumulative effects, we have determined that the activities considered in this biological opinion are not likely to jeopardize the continued existence of Lane Mountain milk-vetch. We reached this conclusion because:

1. The Bureau is not proposing to develop any new routes through known occurrences of this species; and

2. The Bureau will allow stopping, parking, and camping only in previously disturbed areas, which are unlikely to support individuals of this species.

Effects on Critical Habitat of Listed Plants

The Service has not designated critical habitat for triple-ribbed milk-vetch. Therefore, we will not discuss this species further in this section of the biological opinion.

To the best of our knowledge, the Bureau has not designated any open routes that traverse critical habitat of Cushenbury oxytheca. We are unaware of any aspects of the proposed action that may affect its critical habitat in a manner or to a degree that we could measure the effect to the physical and biological features of critical habitat. Consequently, we will not discuss critical habitat of this species further in this section of the biological opinion.

General Discussion of the Effects of Off-highway Vehicle Use on the Physical and Biological Features of Critical Habitat of the Listed Plants

The final supplemental environmental impact statement (Bureau 2019b, section 4.4.1.2) summarizes the effects of off-highway vehicle use on plants and their habitat. Off-highway vehicles can:

1. Reduce the area occupied by plants when a new road or staging area forms;

2. Alter percolation of rain and surface flow;

3. Increase the biomass of plants adjacent to roads because they can receive additional water;

4. Provide a corridor for dispersal of some species of non-native plants; 96

5. Change fire ecology because of increased presence of non-native species;

6. Increase the occurrence of fires started by visitors; and

7. Cause the deposition of fugitive dust.

We consider this list to include those effects that are reasonably certain to occur and will base our analysis on this effects. We will first evaluate how the potential effects of off-highway vehicle use may affect the physical and biological features of critical habitat in a general manner in relation to the proposed action. We will then evaluate the potential effects with regard to the specific taxa.

The first physical and biological feature of critical habitat of each of the three carbonate plants that we will discuss in this section is the soil type on which the species occurs. The same is true for the Lane Mountain milk-vetch. Consequently, we will combine our discussion of the potential effects of off-highway vehicle use on these physical and biological features because we do not expect the effects to be measurably different due to the type of substrate.

The third physical and biological feature of critical habitat of each of the three carbonate plants is similar to that of Lane Mountain milk-vetch. Because we expect that effects to associated plant communities for the carbonate plants are similar to those of Lane Mountain milk-vetch’s host shrubs, we will also combine these discussions.

Plan Amendment I

The Bureau’s proposed action would generally not result in the creation of new routes. The Bureau has proposed to designate as open some portions of existing routes that it had not previously considered open. Therefore, the proposed action would not the affect physical and biological feature associated with soils. Designated routes and previously disturbed areas would not support the “soils with intact, natural surfaces” that comprise the second physical and biological feature of the carbonate species; by definition, these areas are already disturbed and thus lack this physical and biological feature. The associated plant communities of the carbonate plants and host shrubs of Lane Mountain milk-vetch would not occur within existing designated routes and previously disturbed areas; therefore, route designation would not affect this physical and biological feature.

Because the Bureau would reclaim, restore, or rehabilitate transportation linear disturbances, the proposed action would result in a decrease in the degree to which existing disturbed areas alter the percolation of rain and surface flow. We cannot predict the extent to which reclamation, restoration, or rehabilitation would affect percolation of rain and surface flow, because the type of substrate, previous level of use, and the amount of previous disturbance would vary.

The proposed action would not increase the biomass of plants growing adjacent to routes because the Bureau is not creating new routes. The reclamation, restoration, or rehabilitation of transportation linear disturbances is likely to reduce the abundance of non-native plants along 97

these areas over time. The variables we discussed in the previous paragraph would also be factors with regard to plant biomass. Changes in plant biomass would not affect the physical and biological features related to soils. However, reductions in biomass of non-native plant species along transportation linear disturbances would likely reduce stress on the associated plant communities of the carbonate plants and host shrubs of Lane Mountain milk-vetch because it would reduce the potential for competition for water, nutrients, and light with these species.

The reclamation, restoration, or rehabilitation of transportation linear disturbances and the accompanying reduction in increased biomass along their edges would result in fewer opportunities for dispersal of some species of non-native plants. The effects on the physical and biological features of critical habitat of all four species are likely similar to those we discussed in the previous paragraph.

A decrease in the areas where plant biomass is elevated and non-native plants are common would reduce the likelihood of human-caused wildfires. Wildfires would not alter the physical and biological features related to soil types. Wildfires in the action area are unlikely to reach intensities where they affect the ability of the surface to absorb rainfall; however, areas that lack shrub cover are likely to experience greater rates of erosion during rainstorms. The associated plant communities of the carbonate plants and host shrubs of Lane Mountain milk-vetch are not adapted to fire; fire suppression activities would likely adversely affect all of the physical and biological features. Consequently, reducing the amount of critical habitat that supports increased biomass of non-native plants would benefit these species.

The reclamation, restoration, or rehabilitation of a transportation linear disturbance would return, over time, the level of dust generated from that area to its natural condition; the amount of time over which restoration would occur would vary, depending upon the condition of the disturbance and the type of substrate. We do not expect the amount of dust generated by off-highway vehicle use to affect the physical and biological features associated with soil types because the deposition of dust would not alter the basic nature of the substrate. We have no information with regard to whether the deposition of dust on “soils with intact, natural surfaces” has the potential to interfere with the species’ life processes; the final rule designating critical habitat does not discuss dust but instead focuses on more direct disturbances to soils, such as altering them “by ground-disturbing equipment.” We expect that generated dust would not affect the associated plant communities of the carbonate plants and host shrubs of Lane Mountain milk-vetch because these communities and plants are currently present immediately adjacent to designated open routes.

Plan Amendment VI

Because the Bureau has designated as open some routes that were formerly unauthorized, it has increased to a small degree the area where stopping, parking, and camping may occur. This increase in area does not necessarily indicate an increase in disturbance to the physical and biological features of critical habitat of the listed plant species because the Bureau will allow stopping and parking only in previously disturbed areas. The soils and associated plants 98

communities of the carbonate plants and host shrubs of Lane Mountain milk-vetch have already been degraded in these areas. Consequently, the proposed action with regard to stopping, parking, and camping is not likely to adversely affect the physical and biological features of critical habitat of the listed plant species.

IMPLEMENTATION OF THE TRAVEL AND TRANSPORTATION PROGRAM

We described the manner in which the Bureau would implement this program previously in this biological opinion. We do not know the future specific issues that the Bureau would need to address as part of the management of the travel and transportation network. However, during implementation, we expect that these issues would involve minor and localized effects to the physical and biological features of critical habitat of the listed plant species that are generally similar to those that we have discussed previously in this section.

Implementation of the minimization and mitigation actions could result in minor ground disturbance (and therefore disturbance of the physical and biological features of critical habitat of the listed plant species). The Bureau will apply the appropriate conservation and management actions from its land use plan to reduce these effects. Consequently, the Bureau’s implementation of the travel and transportation program is unlikely to affect the physical and biological features of critical habitat of the listed plant species in a measurable manner.

Parish’s Daisy

We will now consider the extent to which the proposed action exposes critical habitat to the effects we discussed in the “General Discussion of the Effects of Off-highway Vehicle Use on the Physical and Biological Features of Critical Habitat of the Listed Plants” section of this biological opinion. We will then consider that information with regard to the effect on the value of critical habitat for the conservation of the species.

The following comments apply to all the tables in this section of the biological opinion; footnotes to individual tables apply only to those tables.

The numbers for all features are for Bureau lands only.

The “acres of critical habitat” remains constant across all alternatives because this number reflects the size of the critical habitat within the action area. 99

Table 19. Effects of the proposed action on critical habitat of Parish’s daisy.

Parish’s Daisy Quantity1 Table1,2 Acres of critical habitat 945 3.4-4 Miles of OHV open and (4.4-3) 4.4-15 limited, non-mechanized, and (4.4) 3.1 non-motorized Miles of transportation linear (3.1) 4.3 disturbance Acres of stopping, parking, (52.2) 38.0 and camping 1 The numbers in parentheses are for the no action alternative (alternative 1); the remaining numbers are for the proposed action (alternative 5). 2 All information is from the errata to the final supplemental environmental impact statement (Toedtli 2019), except for Table 3.4-4, which is from the final supplemental environmental impact statement (Bureau 2019b).

Compared to the no action alternative, the Bureau is proposing to designate 1.3 miles less of route as open. Consequently, less critical habitat (38.0 acres instead of 52.2) is available for stopping, parking, and camping; these previously disturbed areas are unlikely to support “soils with intact, natural surfaces that have not been substantially altered by land use activities” or “associated plant communities” that comprise two of the three physical and biological features of this species’ critical habitat. The other feature of critical habitat, a particular type of soil, is likely to remain in previously disturbed areas, but it lacks value for the conservation of the species absent the other two physical and biological features of critical habitat. The rehabilitation of the transportation linear disturbances may restore, to a small area, the value of critical habitat for the conservation of the species; however, any increase in value is likely to require many years. Because the Bureau will restrict use to previously disturbed areas, the proposed action is likely to minimally affect the physical and biological features of critical habitat of Parish’s daisy.

CONCLUSION

After reviewing the current status of critical habitat, the environmental baseline for the action area, the effects of the proposed action, and the cumulative effects, we have determined that the activities considered in this biological opinion are not likely to result in the destruction or adverse modification of critical habitat of Parish’s daisy. We reached this conclusion because:

1. The Bureau is not proposing to develop any new routes through critical habitat of this species; and

2. The Bureau will allow stopping, parking, and camping only in previously disturbed areas, which generally do not support two of the three physical and biological features of critical habitat of this species. 100

Cushenbury Milk-vetch

Table 20. Effects of the proposed action on critical habitat of Cushenbury milk-vetch.

Cushenbury Milk-vetch Quantity1 Table1,2 Acres of critical habitat 838.5 3.4-4 Miles of OHV open and (3.4) 2.1 (4.4-3) 4.4-15 limited, non-mechanized, and non-motorized Miles of transportation linear (2.6) 3.9 disturbance Acres of stopping, parking, (50.7) 26.9 and camping 1 The numbers in parentheses are for the no action alternative (alternative 1); the remaining numbers are for the proposed action (alternative 5). 2 All information is from the errata to the final supplemental environmental impact statement (Toedtli 2019), except for Table 3.4-4, which is from the final supplemental environmental impact statement (Bureau 2019b).

Compared to the no action alternative, the Bureau is proposing to designate 1.3 miles less of route as open. Consequently, less critical habitat (26.9 acres instead of 50.7) is available for stopping, parking, and camping; these previously disturbed areas are unlikely to support “soils with intact, natural surfaces that have not been substantially altered by land use activities” or “associated plant communities” that comprise two of the three physical and biological features of this species’ critical habitat. The other feature of critical habitat, a particular type of soil, is likely to remain in previously disturbed areas, but it lacks value for the conservation of the species absent the other two physical and biological features of critical habitat. The rehabilitation of the transportation linear disturbances may restore, to a small area, the value of critical habitat for the conservation of the species; however, any increase in value is likely to require many years. Because the Bureau will restrict use to previously disturbed areas, the proposed action is likely to minimally affect the physical and biological features of critical habitat of Cushenbury milk- vetch.

CONCLUSION

After reviewing the current status of its critical habitat, the environmental baseline for the action area, the effects of the proposed action, and the cumulative effects, we have determined that the activities considered in this biological opinion are not likely to result in the destruction or adverse modification of critical habitat of Cushenbury milk-vetch. We reached this conclusion because:

1. The Bureau is not proposing to develop any new routes through critical habitat of this species; and

2. The Bureau will allow stopping, parking, and camping only in previously disturbed areas, which generally do not support the physical and biological features of critical habitat of this species. 101

Cushenbury Buckwheat

Table 21. Effects of the proposed action on critical habitat of Cushenbury buckwheat.

Cushenbury Buckwheat Quantity1 Table1,2 Acres of critical habitat 422.3 3.4-4 Miles of OHV open and (4.4-3) 4.4-15 limited, non-mechanized, and non-motorized (1.2) 0.9 Miles of transportation linear disturbance (1.0) 1.3 Acres of stopping, parking, and camping (19.0) 10.8 1 The numbers in parentheses are for the no action alternative (alternative 1); the remaining numbers are for the proposed action (alternative 5). 2 All information is from the errata to the final supplemental environmental impact statement (Toedtli 2019), except for Table 3.4-4, which is from the final supplemental environmental impact statement (Bureau 2019b).

Compared to the no action alternative, the Bureau is proposing to designate 0.3 mile less of route as open. The amount of critical habitat available for stopping, parking, and camping decreases from 19.0 to 10.8 acres. These previously disturbed areas are unlikely to support “soils with intact, natural surfaces that have not been substantially altered by land use activities” or “associated plant communities” that comprise two of the four physical and biological features of this species’ critical habitat. The other feature of critical habitat, a particular type of soil, is likely to remain in previously disturbed areas, but it lacks value for the conservation of the species absent the other two physical and biological features of critical habitat. The rehabilitation of the transportation linear disturbances may restore, to a small area, the value of critical habitat for the conservation of the species; however, any increase in value is likely to require many years. Because the Bureau will restrict use to previously disturbed areas, the proposed action is likely to minimally affect the physical and biological features of critical habitat of Cushenbury buckwheat.

CONCLUSION

After reviewing the current status of its critical habitat, the environmental baseline for the action area, the effects of the proposed action, and the cumulative effects, we have determined that the activities considered in this biological opinion are not likely to result in the destruction or adverse modification of critical habitat of Cushenbury buckwheat. We reached this conclusion because:

1. The Bureau is not proposing to develop any new routes through critical habitat of this species; and

2. The Bureau will allow stopping, parking, and camping only in previously disturbed areas, which generally do not support the physical and biological features of critical habitat of this species. 102

Lane Mountain Milk-vetch

Table 22. Effects of the proposed action on critical habitat of Lane Mountain milk-vetch.

Lane Mountain Milk-vetch Quantity1 Table1,2 Acres of critical habitat 9,896.9 3.4-4 Miles of OHV open and (24.5) 25.3 (4.4-3) 4.4-15 limited, non-mechanized, and non-motorized Miles of transportation linear (70.6) 69.9 disturbance Acres of stopping, parking, (448.2) 324.1 and camping 1 The numbers in parentheses are for the no action alternative (alternative 1); the remaining numbers are for the proposed action (alternative 5). 2 All information is from the errata to the final supplemental environmental impact statement (Toedtli 2019), except for Table 3.4-4, which is from the final supplemental environmental impact statement (Bureau 2019b).

Under the proposed action, the Bureau is proposing to designate an additional 0.8 mile of open route. Less critical habitat (324.1 acres instead of 448.2) is available for stopping, parking, and camping; the decrease in acreage results from the Bureau’s estimate of the amount of previously disturbed areas adjacent to routes. Previously disturbed areas are unlikely to support the host shrubs that comprise one of the two physical and biological features of this species’ critical habitat. The other feature of critical habitat, a particular type of soil, is likely to remain in previously disturbed areas, but it lacks value for the conservation of the species absent the other physical and biological feature of critical habitat. The proposed action includes the rehabilitation of approximately 69.9 miles of transportation linear disturbances. This rehabilitation may restore the value of critical habitat for the conservation of the species; however, any increase in value is likely to require many years. Because the Bureau will restrict use to previously disturbed areas, the proposed action is likely to minimally affect the physical and biological features of critical habitat of Lane Mountain milk-vetch.

CONCLUSION

After reviewing the current status of its critical habitat, the environmental baseline for the action area, the effects of the proposed action, and the cumulative effects, we have determined that the activities considered in this biological opinion are not likely to result in the destruction or adverse modification of critical habitat of Lane Mountain milk-vetch. We reached this conclusion because:

1. The Bureau is not proposing to develop any new routes through critical habitat of this species; and

2. The Bureau will allow stopping, parking, and camping only in previously disturbed areas, which generally do not support the physical and biological features of critical habitat of this species. 103

REPORTING REQUIREMENTS

The Bureau must provide an annual report to the Service by January 31 of each year after it signs the record of decision for the West Mojave Route Network Project. The annual report must include information regarding the death or injury if desert tortoises and the circumstances of such incidents. If the Bureau moves desert tortoises from harm’s way, please also report this information. Specifically, the reports must include, at a minimum:

1. The date and time of the incident (or when the Bureau discovered the carcass);

2. The location, in a manner that we can use for mapping with GIS;

3. The size and condition of the carcass or desert tortoise;

4. Any other specific information that may be useful to understand the circumstances of the incident; and

5. For desert tortoises moved from harm’s way, the behavior of the desert tortoise after its release.

DISPOSITION OF DEAD OR INJURED DESERT TORTOISES

Within 24 hours of locating a dead desert tortoise, you must notify the Palm Springs Fish and Wildlife Office by telephone (760 322-2070) and by facsimile or electronic mail. The report must include the date, time, and location of the carcass, a photograph, cause of death, if known, and any other pertinent information.

Please notify us immediately if you find an injured desert tortoise. If the injured animal has the potential to survive, the Bureau must take it to a qualified veterinarian for treatment. If the desert tortoise survives, the Bureau must contact the Service regarding its final disposition.

After recording all pertinent information, the Bureau must move carcasses off the route in a manner that reduces the likelihood that someone else will find and report the carcass.

CONSERVATION RECOMMENDATIONS

Section 7(a)(1) of the Endangered Species Act directs Federal agencies to use their authorities to further its purposes by carrying out conservation programs for the benefit of endangered and threatened species. Conservation recommendations are discretionary agency activities to minimize or avoid adverse effects of a proposed action on listed species or critical habitat, to help implement recovery plans, or to develop information. We have no conservation recommendations at this time.

RE-INITIATION NOTICE

This concludes formal consultation on the Bureau’s propos West Mojave Route Network Project. 104

As provided in 50 CFR402.16, re-initiation of formal consultation is required where discretionary Federal agency involvement or control over the action has been retained (or is authorized by law) and if:

1. The amount or extent of incidental take specified in the incidental take statement is exceeded;

2. New information reveals effects of the agency action that may affect listed species or critical habitat in a manner or to an extent not considered in this opinion;

3. The agency action is subsequently modified in a manner that causes an effect to the listed species or critical habitat that was not considered in the biological opinion or written concurrence; or

4. A new species is listed or critical habitat designated that may be affected by the action.

Additionally, re-initiation is not required after the approval of a land management plan prepared pursuant to 43 U.S.C. 1712 or 16 U.S.C. 1604 upon listing of a new species or designation of new critical habitat if the land management plan has been adopted by the agency as of the date of listing or designation, provided that any authorized actions that may affect the newly listed species or designated critical habitat will be addressed through a separate action-specific consultation. This exception to re-initiation of consultation does not apply to those land management plans prepared pursuant to 16 U.S.C. 1604 if:

1. Fifteen years have passed since the date the agency adopted the land management plan prepared pursuant to 16 U.S.C. 1604; and

2. Five years have passed since the enactment of Public Law 115–141 [March 23, 2018] or the date of the listing of a species or the designation of critical habitat, whichever is later.

In instances where the amount or extent of incidental take is exceeded, the exemption issued pursuant to section 7(o)(2) may lapse and any further take may be a violation of section 4(d) or 9. Consequently, we recommend that any operations causing such take cease pending re-initiation.

Appendices 105

REFERENCES CITED

Abella, S. 2010. Disturbance and Plant Succession in the Mojave and Sonoran Deserts of the American Southwest. International Journal of Environmental Research and Public Health, 7:1248–1284.

Aber, J.D., K.J. Nadelhoffer, P. Steudler, and J.M. Melillo. 1989. Nitrogen saturation in northern forest ecosystems. Bioscience 39:378-386.

Allison, L.J. and A.M. McLuckie. 2018. Population trends in Mojave desert tortoises (Gopherus agassizii). Herpetological Conservation and Biology 13(2):433-452.

Anderson, P., 2002. Roads as barriers. In: Sherwood, B., Butler, D., J. Burton.) (Eds.), Wildlife and Roads: The Ecological Impact. London, Imperial College Press169–184.

Andrews, K.M., Gibbons, J.W., Reeder, T.W., 2005. How do highways influence snake movement? Behavioral responses to roads and vehicles. Copeia 772–782.

Averill-Murray, R.C., C.R. Darst, N. Strout, and M. Wong. 2013. Conserving Population Linkages for the Mojave Desert Tortoise (Gopherus agassizii). Herpetological Conservation and Biology 8(1):1–15.

Belnap, J. 1996. Soil surface disturbance in cold deserts: effects on nitrogenase activity in cyanobacterial-lichen soil crusts. Biology and Fertility of Soils 23:362-367.

Brooks, M.L. and T.C. Esque 2002. Alien annual plants and wildfire in desert tortoise habitat: status, ecological effects, and management. Chelonian Conservation and Biology 4:330- 340.

Brooks, M.L. 2003. Effects of increased soil nitrogen on the dominance of alien annual plants in the Mojave Desert. Journal of Applied Ecology 40:344-353.

Brooks, M.L. and J.R. Matchett. 2006. Spatial and temporal patterns of wildfires in the Mojave Desert, 1980-2004. Journal of Arid Environments 67:148-164.

Brooks, M.L; S. Ostoja, and R. Klinger. 2013. Fire Effects on Seed banks and Vegetation in the Eastern Mojave Desert: Implications for Post-fire Management. U.S. Joint Fire Science Program. 81. Lincoln, Nebraska.

[Bureau] Bureau of Land Management. 2005. Final environmental impact report and statement for the West Mojave Plan; a habitat conservation plan and California Desert Conservation Area Plan amendment. Moreno Valley, San Bernardino, and Barstow, California. 106

[Bureau] Bureau of Land Management. 2014. Report of implementation of terms and conditions for the California Desert Conservation Area Plan biological opinion 1-8-03-F-58 (West Mojave Plan). Dated May 29. Memorandum to Field Supervisor, Ventura Fish and Wildlife Office, Ventura, California. From Field Manager, Barstow Field Office. Barstow, California.

[Bureau] Bureau of Land Management. 2015a. Desert Renewable Energy Conservation Plan. Proposed land use plan amendment and final environmental impact statement. Dated October. Sacramento, California.

[Bureau] Bureau of Land Management. 2015b. Report of implementation of terms and conditions for the California Desert Conservation Area Plan biological opinion 1-8-03-F- 58 (West Mojave Plan) as amended November 30, 2007. Dated January 7. Memorandum to Assistant Field Supervisor, Palm Springs Fish and Wildlife Office, U.S. Fish and Wildlife Service, Palm Springs, California. From District Manager, California Desert District. Barstow, California.

[Bureau] Bureau of Land Management. 2018. PBO Annual Report 2018. Dated April 8, 2018. Email to Division Chief, West Mojave Division, U.S. Fish and Wildlife Service, Palm Springs, California. From District Biologist, California Desert District, Palm Springs, California.

[Bureau] Bureau of Land Management. 2019a. Request to initiate formal consultation for listed species and critical habitat on the West Mojave Route Network Project. Dated April 22, 2019. Memorandum to Assistant Field Supervisor, Palm Springs Fish and Wildlife Office, U.S. Fish and Wildlife Service, Palm Springs, California. From Acting District Manager, California Desert District, Bureau of Land Management, Moreno Valley, California.

[Bureau] Bureau of Land Management. 2019b. West Mojave Route Network Project Final California Desert Conservation Plan Amendment and Supplemental Environmental Impact Statement for the California Desert District. Dated April 2019.

[Bureau] Bureau of Land Management. 2019c. Report: Biological Opinion for Activities in the California Desert Conservation Area, from October 2017 to October 2018. Dated April 8. From District Wildlife Biologist, California Desert District, Bureau of Land Management. Palm Springs, California.

[Bureau] Bureau of Land Management. 2019d. Comments received on draft biological opinion for the West Mojave Route Network Project. Dated September 26, 2019. Memorandum to Acting Assistant Field Supervisor, Palm Springs Fish and Wildlife Office, U.S. Fish and Wildlife Service, Palm Springs, California. From Field Managers, Bureau of Land Management, Barstow and Ridgecrest, California. 107

Christensen, J. H. , Hewitson, B. , Busuioc, A. , Chen, A. , Gao, X. , Held, R. , Jones, R. , Kolli, R. K. , Kwon, W. K. , Laprise, R. , Magana Rueda, V. , Mearns, L. , Menendez, C. G. , Räisänen, J. , Rinke, A. , Sarr, A. , Whetton, P. , Arritt, R. , Benestad, R. , Beniston, M. , Bromwich, D. , Caya, D. , Comiso, J. , de Elia, R. and Dethloff, K. 2007. Regional climate projections, Climate Change, 2007: The Physical Science Basis. Contribution of Working group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, University Press, Cambridge, Chapter 11, ISBN: 978-0-521-88009-1.

D'Antonio, C. M. and P. M. Vitousek.1992. Biological invasions by exotic grasses, the grass/fire cycle, and global change. Annual review of ecology and systematics 23(1):63-87.

Darst 2014. Impervious surface calculations. Excel Spreadsheet. May 6.

DeFalco, L.A., J.K. Detling, C.R. Tracy, and S.D. Warren. 2001. Physiological variation among native and exotic winter annual plants associated with microbiotic crusts in the Mojave Desert. Plant and Soil 234:10-14.

Drake, K.K., T.C. Esque, K.E. Nussear, L.A. Defalco, S.J. Scoles-Sciulla, A.T. Modlin, and P.A.Medica. 2015. Desert Tortoise Use of Burned Habitat in the Eastern Mojave Desert. The Journal of Wildlife Management; DOI: 10.1002/jwmg.874.

Eigenbrod, F., S.J. Hecnar, and L. Fahrig. 2009. Quantifying the road-effect zone: Threshold effects of a motorway on anuran populations in Ontario, Canadian Ecological Society. 14-24.

Esque, T.C., C.R. Schwalbe, L.A. DeFalco, R.B. Duncan, and T.J. Hughes. 2003. Effects of desert wildfires on Desert Tortoise (Gopherus agassizii) and other small vertebrates. Southwestern Naturalist 48:103-111.

Forman, R.T. and Alexander, L.E., 1998. Roads and their major ecological effects. Annual Review of Ecology and Evolutionary Systems 29: 207–231.

Forman, R.T. and Deblinger, R.D., 2000. The ecological road-effect zone of a Massachusetts (U.S.A.) suburban highway. Conservation Biology 14: 36–46.

Forman, R.T.T., D. Sperling, J.A. Bissonette, A.P. Clevenger, C.D. Cutshall, V.H. Dale, L. Fahrig, R. France, C.R. Goldman, K. Heanue, J.A. Jones, F.J. Swanson, T. Turrentine, and T.C. Winter. 2003. Road Ecology: Science and Solutions. Island Press,Covelo, CA.

Fraga, N., T. La Doux, L. Prince, M. Harding, and J. Hoines. 2015. Conservation assessment for triple-ribbed milkvetch (Astragalus tricarinatus, Fabaceae) in Joshua Tree National Park. Natural Resource Report NPS/JOTR/NRR—2015/999. National Park Service, Fort Collins, Colorado. 108

Fry, J.A., G. Xian, S. Jin, J.A. Dewitz, C.G. Homer, L. Yang, C.A. Barnes, N.D. Herold, and J.D. Wickham. 2011. National Land Cover Database for the Conterminous United States. Analysis of land cover change in the continental United States from 2001 to 2006 using Landsat ETM+ and TM imagery. 9 pp.

Grandmaison, D.D., M.F. Ingraldi, and F.R. Peck. 2010. Desert tortoise microhabitat selection on the Florence Military Reservation, South-Central Arizona. Journal of Herpetology 44(4):581-590.

Gray, M. E., B. G. Dickson, K. E. Nussear, T. C. Esque, and T. Chang. 2019. A range-wide model of contemporary, omnidirectional connectivity for the threatened Mojave desert tortoise. Ecosphere 10(9):e02847. 10.1002/ecs2.2847.

Henen, B.T. 2019. Electronic mail. Number of desert tortoises found on the Marine Corps Air Ground Combat Center at Twentynine Palms expansion project. Dated January 25. Ecologist, Marine Corps Air Ground Combat Center, Twentynine Palms, California.

Hoffmann, S. 2019. Personal communication. Mileage of routes on private lands in the action area. Date August 28. Fish and Wildlife Biologist, Palm Springs Fish and Wildlife Office, U.S. Fish and Wildlife Service. Palm Springs, California.

Hughson, D.L. and N. Darby. 2013. Desert tortoise road mortality in Mojave National Preserve, California. California Fish and Game 99:222–232.

Latch, E.K., W.I. Boarman, A. Walde, and R.C. Fleischer. 2011. Fine-scale analysis reveals cryptic landscape genetic structure in desert tortoises. PLOS ONE 6(11):e27794. doi:10.1371/journal.pone.0027794.

Longshore, K.M., J.R. Jaeger, and J.M. Sappington. 2003. Desert tortoise (Gopherus agassizii) survival at two eastern Mojave Desert sites: death by short-term drought? Journal of Herpetology 37(1):169-177.

Lovich, J.E., Daniels, R., 2000. Environmental characteristics of desert tortoise (Gopherus agassizii) burrow locations in an altered industrial landscape. Chelonian Conservation and Biology 3, 714–721.

Nafus, M.G., T.D.Tuberville, K.A. Biuhlman, B.D. Todd. 2013. Relative abundance and demographic structure of Agassiz’s desert tortoise (Gopherus agassizii) along roads of varying size and traffic volume. Biological Conservation 162: 100-106.

Nelson, K. 2019. Annual desert tortoise status report for the Alta East Wind Project. Biological opinion 8-8-13-F-19. Dated January 10. Alta X Wind, LLC. Mojave, California. 109

Nussear, K.E., T.C. Esque, R.D. Inman, L. Gass, K.A. Thomas, C.S.A. Wallace, J.B. Blainey, D.M. Miller, and R.H. Webb. 2009. Modeling habitat of the desert tortoise (Gopherus agassizii) in the Mojave and parts of the Sonoran Deserts of California, Nevada, Utah, and Arizona. U.S. Geological Survey Open-File Report 2009-1102.

Oftedal, O.T., S. Hillard, and D.J. Morafka. 2002. Selective spring foraging by juvenile desert tortoises (Gopherus agassizii) in the Mojave Desert: Evidence of an adaptive nutritional strategy. Chelonian Conservation and Biology 4:341-352.

Olson, T.G. 2003. Carbonate Habitat Management Strategy. Report to San Bernardino National Forest Association. 95 pp.

Peaden, J.M., T.D. Tuberville, K.A. Buhlmann, M.G. Nafus, and B.D. Todd. 2015. Delimitating road-effect zones for threated species: implications for mitigation fencing. Wildland Resources 42: 650–659.

Peaden, J.M., A.J. Nowokowski, T.D. Tuberville, K.A. Buhlmann, and B.D. Todd. 2017. Effects of roads and roadside fencing on movements, space use, and carapace temperatures of a threatened tortoise. Biological Conservation 214: 13-22.

[Service] U.S. Fish and Wildlife Service. 1994. Desert tortoise (Mojave population) recovery Plan. Portland, Oregon.

[Service] U.S. Fish and Wildlife Service. 1997. San Bernardino Mountains Carbonate Plants Draft Recovery Plan. U.S. Fish and Wildlife Service, Portland, Oregon. 51 pp.

[Service] U.S. Fish and Wildlife Service. 2004. Biological opinion on the Addition of Maneuver Training Lands at Fort Irwin, California. Dated March 2004. Letter to Colonel Edward L. Flinn, Deputy, commander and Chief of Staff, National Training Center and Fort Irwin, Fort Irwin, California. From Diane K. Noda, Field Supervisor, Ventura Fish and Wildlife Office. Ventura, California.

[Service] U.S. Fish and Wildlife Service. 2006. Biological opinion for the California desert conservation area plan (West Mojave Plan). Memorandum to District Manager, California Desert District, Bureau of Land Management, Moreno Valley, California. Dated November 30, 2007. From Field Supervisor, Ventura Fish and Wildlife Office. Ventura, California.

[Service] U.S. Fish and Wildlife Service. 2008a. Environmental Assessment to Implement a Desert Tortoise Recovery Plan Task: Reduce Common Raven Predation on the Desert Tortoise. Dated March 2008. U.S. Fish and Wildlife Service, Ventura, California.

[Service] U.S. Fish and Wildlife Service. 2008b. Astragalus jaegerianus (Lane Mountain milkvetch) 5-year review: summary and evaluation. Carlsbad Fish and Wildlife Office. Carlsbad, California. 110

[Service] U.S. Fish and Wildlife Service. 2009a. Astragalus tricarinatus (triple-ribbed milkvetch) 5-year review: summary and evaluation. Carlsbad Fish and Wildlife Office. Carlsbad, California.

[Service] U.S. Fish and Wildlife Service. 2009b. Acanthoscyphus (Oxytheca) parishii var. goodmaniana (cushenbury oxytheca) 5-year review: summary and evaluation. Carlsbad Fish and Wildlife Office. Carlsbad, California.

[Service] U.S. Fish and Wildlife Service. 2009c. Erigeron parishii (Parish’s daisy) 5-year review: summary and evaluation. Carlsbad Fish and Wildlife Office. Carlsbad, California.

[Service] U.S. Fish and Wildlife Service. 2009d. Astragalus albens (cushionberry milkvetch) 5- year review: summary and evaluation. Carlsbad Fish and Wildlife Office. Carlsbad, California.

[Service] U.S. Fish and Wildlife Service. 2009e. Eriogonum ovalifolium var. vineum (cushionberry buckwheat) 5-year review: summary and evaluation. Carlsbad Fish and Wildlife Office. Carlsbad, California.

[Service] U.S. Fish and Wildlife Service. 2010. Mojave population of the desert tortoise (Gopherus agassizii) 5-year review: summary and evaluation. Desert Tortoise Recovery Office. Reno, Nevada.

[Service] U.S. Fish and Wildlife Service. 2011. Revised recovery plan for the Mojave population of the desert tortoise (Gopherus agassizii). Sacramento, California.

[Service] U.S. Fish and Wildlife Service. 2012. Biological opinion for the Proposed Addition of Maneuver Training Lands at Fort Irwin, California (8-8-11-F-38R). Memorandum to Colonel, Headquarters, National Training Center and Fort Irwin, Fort Irwin, California. Dated April 27. From Field Supervisor, Ventura Fish and Wildlife Office. Ventura, California.

[Service] U.S. Fish and Wildlife Service. 2014. Biological opinion for the Olancha/Cartago four- lane project (09-INY-395, PM 29.2/41.8 EA 09-21340), Inyo County, California. Memorandum to Branch Chief, Central Region Biology North Branch, California Department of Transportation, District 6. Fresno, California. From Field Supervisor, Carlsbad Fish and Wildlife Office. Carlsbad, California.

[Service] U.S. Fish and Wildlife Service. 2015a. Update on Mojave desert tortoise population trends. Dated June 19. Desert Tortoise Recovery Office. Reno, Nevada.

[Service] U.S. Fish and Wildlife Service. 2015b. Range-wide monitoring of the Mojave desert tortoise (Gopherus agassizii): 2013 and 2014 annual reporting. Report by the Desert Tortoise Recovery Office, U.S. Fish and Wildlife Service, Reno, Nevada. 111

[Service] U.S. Fish and Wildlife Service. 2015c. Biological opinion for North Big Bear, Baldwin Lake, and Bluff Mesa fuels reduction projects, Mountaintop Ranger District, San Bernardino National Forest, California. Letter to Forest Supervisor. From Field Supervisor, Carlsbad Fish and Wildlife Office. Carlsbad, California.

[Service] U.S. Fish and Wildlife Service. 2016a. Biological opinion for the Proposed Land Use Plan Amendment under the Desert Renewable Energy Plan. Memorandum to Deputy State Director, Division of Natural Resources, Bureau of Land Management, Sacramento, California. Dated August 16. From Field Supervisor, Carlsbad Fish and Wildlife Office. Carlsbad, California.

[Service] U.S. Fish and Wildlife Service. 2016b. Range-wide monitoring of the Mojave desert tortoise (Gopherus agassizii): 2015 annual reporting. Report by the Desert Tortoise Recovery Office, U.S. Fish and Wildlife Service, Reno, Nevada.

[Service] U.S. Fish and Wildlife Service. 2017a. Biological opinion on the Land Acquisition and Airspace Establishment, Twentynine Palms, California. Letter to Lieutenant Colonel of Marine Air Ground Task Force Training Command, Twentynine Palms, California. Dated January 31. From Field Supervisor, Carlsbad Fish and Wildlife Office. Carlsbad, California.

[Service] U.S. Fish and Wildlife Service. 2017b. Formal Section 7 Consultation for the Mitsubishi South Quarry Expansion, Mountaintop Ranger District, San Bernardino National Forest, San Bernardino County, California. Letter to Forest Supervisor. From Assistant Field Supervisor, Palm Springs Fish and Wildlife Office, U.S. Fish and Wildlife Service. Palm Springs, California.

[Service] U.S. Fish and Wildlife Service. 2018. Range-wide monitoring of the Mojave desert tortoise (Gopherus agassizii): 2017 annual reporting. Report by the Desert Tortoise Recovery Office, U.S. Fish and Wildlife Service, Reno, Nevada.

[Service] U.S. Fish and Wildlife Service. 2019a. Draft biological opinion for the West Mojave Route Network Project, San Bernardino, Inyo, Kern, Riverside, and Los Angeles Counties, California (6840 (P) LLCAD00000). From Assistant Field Supervisor, Palm Springs Fish and Wildlife Office, U.S. Fish and Wildlife Service, Palm Springs, California. From Acting District Manager, California Desert District, Bureau of Land Management, Moreno Valley, California.

[Service] U.S. Fish and Wildlife Service. 2019b. Biological opinion for proposed activities within the Cuddeback Range land withdrawal at the Naval Air Weapons Station, China Lake, California (FWS-INY-KRN-SBR-16B0219-19F0246). Memorandum to Head, Environmental Management, Division Naval Air Weapons Station, China Lake, California. Dated March 21, 2019. From Acting Field Supervisor, Carlsbad Fish and Wildlife Office. Carlsbad, California. 112

[Service] U.S. Fish and Wildlife Service. 2019c. Range-wide monitoring of the Mojave desert tortoise (Gopherus agassizii): 2018 annual reporting. Report by the Desert Tortoise Recovery Office, U.S. Fish and Wildlife Service, Reno, Nevada.

[Service] U.S. Fish and Wildlife Service. 2019d. Biological Opinion on the Ongoing Activities that Affect Twelve Mountain Plant Species in the San Bernardino National Forest, California. Letter to Forest Supervisor. From Assistant Field Supervisor, Palm Springs Fish and Wildlife Office, U.S. Fish and Wildlife Service. Palm Springs, California.

Shanley, C.S. and S. Pyare. 2011. Evaluating the road-effect zone on wildlife distribution in a rural landscape. Ecosphere 2: 6.

Sharifi, M., A.C. Gibson, and P.W. Rundel. 1997. Surface dust impacts on gas exchange in Mojave Desert shrubs. Journal of Applied Ecology 34:837-846.

Shepard, D.B., Kuhns, A.R., Dreslik, M.J., Phillips, C.A., 2008. Roads as barriers to animal movement in fragmented landscapes. Anim. Conserv. 11, 288–296.

Tracy, C.R., R. Averill-Murray, W.I. Boarman, D. Delehanty, J. Heaton, E. McCoy, D. Morafka, K. Nussear, B. Hagerty, and P. Medica. 2004. Desert Tortoise Recovery Plan Assessment. Prepared for the U.S. Fish and Wildlife Service. Reno, Nevada.

Von Seckendorff, H.K., Marlow, R.W., 2002. Impacts of vehicle road traffic on desert tortoise populations with consideration of conservation of tortoise habitat in southern Nevada. Chelonian Conservation Biology 4, 449–456.

Personal Communication

Allison, L. 2019. Personal communication. Projection of the number of large desert tortoises in the Western Mojave Recovery Unit in 2019 and 2024. Dated September 20. Desert Tortoise Monitoring Coordinator, Desert Tortoise Recovery Office, U.S. Fish and Wildlife Service. Reno, Nevada.

Davis, D. 2019. Personal communication. Report of a desert tortoise mortality. Dated June 5. Clearway Energy Group. Moapa, Nevada.

Hoffmann, S. 2019. Personal communication. Mileage of lands on private lands in the action area. Date August 28. Fish and Wildlife Biologist, Palm Springs Fish and Wildlife Office, U.S. Fish and Wildlife Service. Palm Springs, California.

Symons, K. 2019. Personal communication. Description of the proposed action. Electronic mail. Dated August 21. Field Manager, Barstow Field Office, Bureau of Land Management. Barstow, California. 113

Toedtli, M. 2019. Personal communication. WEMO FSEIS/LUPA - ESA Biological Opinion (Dingell Act errata). Dated August 30. Planning and Environmental Coordinator, Barstow Field Office, Bureau of Land Management, Barstow, California.

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APPENDIX B

SOLAR PROJECTS FOR WHICH THE U.S. FISH AND WILDLIFE SERVICE HAS ISSUED BIOLOGICAL OPINIONS OR INCIDENTAL TAKE PERMITS

The following table summarizes information regarding the solar projects that have undergone formal consultation with regard to the desert tortoise. In the Citations column, a single reference indicates that the acres of desert tortoise habitat and number of desert tortoises are estimates from the biological opinion; when the column includes two citations, the first is for the acreage of habitat and the estimated number of desert tortoises from the biological opinion and the second is for number of desert tortoises that were found onsite prior to or during construction.

Project and Recovery Acres of Desert Desert Tortoises Desert Tortoises Citations3 Unit Tortoise Habitat Estimated1 Observed2

Eastern Mojave Ivanpah Solar Electric Service 2011a, Davis 3,582 1,136 1757 Generating System 2014 Service 2013a, Stateline 1,685 947 55 Ironwood Consulting, 2014 Silver State North – Service 2010, Cota 685 146 7 NV 2013 Silver State South – Service 2013a, Cota 2,4274 1,0204 152 NV 2014 Amargosa Farm Road 4,350 46 - Service 2010f – NV Nevada Solar One - 400 5 5 Burroughs 2012, 2014 NV Copper Mountain 1,540 305 305 Burroughs 2012, 2014 North - NV Copper Mountain - NV 380 5 5 Burroughs 2012, 2014 Townsite - NV 936 48 - Burroughs 2015 Techren Boulder City - 2,304 159 - Burroughs 2015 NV Western Mojave Primarily in

abandoned 46 Abengoa Harper Lake - Service 2011b agricultural fields Chevron Lucerne 516 10 - Service 2010b Valley Service 2015a, Daitch Cinco 500 53 2 2015 Soda Mountain 1,726 78 - Service 2015b Northeastern Mojave 115

Project and Recovery Acres of Desert Desert Tortoises Desert Tortoises Citations3 Unit Tortoise Habitat Estimated1 Observed2

Res Americas Moapa Solar 951 95 - Burroughs 2015 Energy Center - NV Service 2012, Moapa K Road Solar - 2,141 186 177 Burroughs NV 2013 Colorado Service 2010c, Fraser Genesis 1,774 8 0 2014a Service 2010d, Fraser Blythe 6,958 30 0 2014b Service 2011c, Fraser Desert Sunlight 4,004 56 7 2014a Service 2013b, Fraser McCoy 4,533 15 0 2014b Desert Harvest 1,300 5 - Service 2013c Service 2011d, Fraser Rice 1,368 18 1 2014a Total 47,816 4,363 660 1The numbers in this column are not necessarily comparable because the methodologies for estimating the numbers of desert tortoises occasionally vary between projects. When available, we included an estimate of the numbers of small desert tortoises. 2This column reflects the numbers of desert tortoises observed within project areas. It includes translocated animals and those that were killed by project activities. Project activities may result in the deaths of more desert tortoises than are found. Dashes represent projects for which we have no information at this point; some projects had not broken ground at the time of this biological opinion. 3The first citation in this column is for both the acreage and the estimate of the number of desert tortoises. The second is for the number of desert tortoises observed during construction of the project; where only one citation is present, construction has not begun or data are unavailable at this time. 4These numbers include Southern California Edison’s Primm Substation and its ancillary facilities. 5These projects occurred under the Clark County Multi-species Habitat Conservation Plan; the provisions of the habitat conservation plan do not require the removal of desert tortoises. We estimate that all six projects combined will affect fewer than 50 desert tortoises. 6These estimates do not include smaller desert tortoises. 7In the table attached to the electronic mail, the number of desert tortoises translocated from the project site is represented by the total number of translocated animals minus the number of animals born in the holding pens. 8The estimate of the number of desert tortoises is from the portion of the project on WAPA land (20.39 acres). The remaining lands are covered by the Clark County Multi-species Habitat Conservation Plan; see footnote 5. 9The estimate of the number of desert tortoises is from both Bureau (104 acres) and private (2,200 acres) land. The remaining lands are covered by the Clark County Multi-species Habitat Conservation Plan; see footnote 5. 10Of the 80-acre project site, 76.4 acres were left intact (there was crushing and mowing of vegetation but no blading) with openings along the bottom of the fence. After project completion, four tortoises were released back into the solar facility on September 25, 2017. One adult has left and re-entered the facility twice and the one juvenile has remained within the facility. 116

REFERENCES CITED FOR APPENDIX B

Burroughs, M. 2012. Electronic mail. Information on solar projects in desert tortoise habitat in Nevada for which the Service has issued biological opinions. Dated April 26. Fish and wildlife biologist, Southern Nevada Fish and Wildlife Office, U.S. Fish and Wildlife Service. Las Vegas, Nevada.

Burroughs, M. 2014. Electronic mail. Status of solar projects in Nevada. Dated January 27. Fish and wildlife biologist, Southern Nevada Fish and Wildlife Office, U.S. Fish and Wildlife Service. Las Vegas, Nevada.

Cota, M. 2014. Electronic mail. Number of desert tortoises found on the Silver State South Project site. Dated November 25. Wildlife biologist, Pahrump Field Office, Bureau of Land Management. Las Vegas, Nevada.

Daitch, D. 2015. Electronic mail. Notifications of desert tortoises found on the Cinco Solar project. Dated November 6. Rincon Consultants. Monterey, California.

Davis, D. 2014. Electronic mail. ISEGS master tortoise list, October 2014. Dated November 3. Environmental specialist III, Ivanpah Solar Thermal, Nipton, California.

Fraser, J. 2014a. Electronic mail. Number of desert tortoises found on the Genesis and Desert Sunlight solar sites. Dated January 28. Fish and wildlife biologist, Palm Springs Fish and Wildlife Office, U.S. Fish and Wildlife Service. Palm Springs, California.

Fraser, J. 2014b. Electronic mail. Number of desert tortoises found on the Blythe and McCoy solar sites. Dated November 5. Fish and wildlife biologist, Palm Springs Fish and Wildlife Office, U.S. Fish and Wildlife Service. Palm Springs, California.

Ironwood Consulting, Inc. 2014. Annual compliance report: April - December 2014. Biological resources. Stateline Solar Farm. Bureau of Land Management case file number: CACA- 48669. San Bernardino County, California.

[Service] U.S. Fish and Wildlife Service. 2010b. Formal consultation for the Silver State Solar Project (NextLight Renewable Power, LLC), Clark County, Nevada. File No. 84320- 2010-F- 0208. Dated September 16. Memorandum to Field Manager, Pahrump Field Office, Bureau of Land Management, Las Vegas, Nevada. From State Supervisor, Nevada Fish and Wildlife Office. Reno, Nevada.

[Service] U.S. Fish and Wildlife Service. 2010c. Revised biological opinion for the Lucerne Valley Chevron Solar Project, San Bernardino County, California (3031 (P) CA-680.33) (8-8-10-F- 61R). Memorandum to Field Manager, Barstow Field Office, Bureau of Land Management, Barstow, California. Dated September 29. From Field Supervisor, Ventura Fish and Wildlife Office. Ventura, California. 117

[Service] 2010d. Biological opinion on the Genesis Solar Energy Project, Riverside County, California. Memorandum to Field Manager, Palm Springs South Coast Field Office, Bureau of Land Management, Palm Springs, California. Dated November 2. From Field Supervisor, Carlsbad Fish and Wildlife Office. Carlsbad, California.

[Service] 2010f. Formal and informal consultation under section 7 of the Endangered Species Act for the Amargosa Farm Road Solar Energy Project, Nye County, Nevada. File nos. 84320-2010-F-0315 and 84320-2010-1-0316. Memorandum to Field Manager, Pahrump Field Office, Bureau of Land Management, Las Vegas, Nevada. Dated November 1. From State Supervisor, Nevada Fish and Wildlife Office. Reno, Nevada.

[Service] U.S. Fish and Wildlife Service (Service). 2011a. Revised recovery plan for the Mojave population of the desert tortoise (Gopherus agassizii). Sacramento, California.

[Service] U.S. Fish and Wildlife Service. 2011b. Biological opinion on BrightSource Energy’s Ivanpah Solar Electric Generating System Project, San Bernardino County, California [CACA- 48668, 49502, 49503, 49504] (8-8-10-F-24R). Dated June 10. Memorandum to District Manager, California Desert District, Bureau of Land Management, Moreno Valley, California. From Field Supervisor, Ventura Fish and Wildlife Office. Ventura, California.

[Service] U.S. Fish and Wildlife Service. 2011c. Biological opinion on Copper Mountain North Solar Project, Boulder City, Clark County, Nevada. Memorandum to Field Manager, Las Vegas Field Office, Bureau of Land Management, Las Vegas, Nevada; Director, Public Works, City of Boulder City, Boulder City, Nevada; Adaptive Management Coordinator, Desert Conservation Program, Las Vegas, Nevada; Supervisory Biologist – Habitat, Nevada Department of Wildlife, Las Vegas, Nevada. Dated December 29. From State Supervisor, Nevada Fish and Wildlife Office. Reno, Nevada.

[Service] U.S. Fish and Wildlife Service. 2011d. Biological opinion on the Mojave Solar, LLC’s Mojave Solar Project, San Bernardino County, California (8-8-11-F-3). Letter sent to Director of Environmental Compliance, Loan Guarantee Program, Department of Energy, Washington, D.C. and Field Manager, Barstow Field Office, Bureau of Land Management, Barstow, California. Dated March 17. From Field Supervisor, Ventura Fish and Wildlife Office. Ventura, California.

[Service] U.S. Fish and Wildlife Service. 2012. Biological opinion for the K Road Moapa Solar Project, Moapa River Indian Reservation, Clark County, Nevada. Memorandum to Superintendent, Southern Paiute Agency, Bureau of Indian Affairs. St. George, Utah. Dated March 7. From State Supervisor, Nevada Fish and Wildlife Office. Reno, Nevada. 118

[Service] U.S. Fish and Wildlife Service. 2013a. Biological opinion for the Stateline Solar and Silver State Solar South Projects, San Bernardino County, California, and Clark County, Nevada. Dated September 30. Memorandum to Field Manager, Needles Field Office, Bureau of Land Management, Needles California, and Assistant Field Manager, Las Vegas Field Office, Bureau of Land Management, Las Vegas, Nevada. From Acting Field Supervisor, Ventura Fish and Wildlife Office. Ventura, California.

[Service] U.S. Fish and Wildlife Service. 2013b. Biological opinion reinitiation of Copper Mountain North Solar Project, Boulder City, Clark County, Nevada. Memorandum to Field Manager, Las Vegas Field Office, Bureau of Land Management, Las Vegas, Nevada; Director, Public Works, City of Boulder City, Boulder City, Nevada; Adaptive Management Coordinator, Desert Conservation Program, Las Vegas, Nevada; Supervisory Biologist – Habitat, Nevada Department of Wildlife, Las Vegas, Nevada. Dated August 8. From State Supervisor, Nevada Fish and Wildlife Office. Reno, Nevada.

[Service] U.S. Fish and Wildlife Service. 2013c. Biological opinion on the McCoy Solar Power Project, Riverside County, California. Dated March 6. Memorandum to Field Manager, California Desert District Office, Bureau of Land Management, Moreno Valley, California. From Field Supervisor, Carlsbad Fish and Wildlife Office. Carlsbad, California.

[Service] U.S. Fish and Wildlife Service. 2015a. Biological opinion for the Valley Electric Association’s Community Solar Project Low-Effect Habitat Conservation Plan. Dated October 8. Memorandum to Assistant Regional Director, Ecological Services, Sacramento, California; Supervisory Biologist – Habitat, Nevada Department of Wildlife, Las Vegas, Nevada. From Field Supervisor, Southern Nevada Fish and Wildlife Office. Las Vegas, Nevada.

[Service] U.S. Fish and Wildlife Service. 2015b. Biological opinion for the RE Barren Ridge 1 LLC’s RE Cinco Generation Intertie Line and RE Cinco Solar Project, Kern County, California (2831-03 (P) CACA-53735 CAD000.06). Dated February 11. Memorandum to Field Manager, Ridgecrest Field Office, Bureau of Land Management, Ridgecrest, California, and Deputy Regional Director, Region 8, U.S. Fish and Wildlife Service, Sacramento, California. From Field Supervisor, Carlsbad Fish and Wildlife Office. Carlsbad, California.