Endangered and Threatened Wildlife; Endangered Species Status for Southern Mountain Caribou Distinct Population Segment

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R1-ES-2012-0097; FXES11130900000C2-189-FF09E42000]

RIN 1018-BC84

Endangered and Threatened Wildlife; Endangered Species Status for Southern Mountain Caribou Distinct Population Segment

AGENCY:

Fish and Wildlife Service, Interior.

ACTION:

Final rule.

SUMMARY:

We, the U.S. Fish and Wildlife Service (Service), determine endangered species status under the Endangered Species Act of 1973, as amended (Act), for the southern mountain caribou distinct population segment (DPS) of woodland caribou (

Rangifer tarandus caribou

). This determination amends the current listing of the southern Selkirk Mountains population of woodland caribou by defining the southern mountain caribou DPS. The southern mountain caribou DPS of woodland caribou consists of 17 subpopulations (15 extant and 2 extirpated). This DPS includes the currently listed southern Selkirk Mountains population of woodland caribou, a transboundary population that moves between British Columbia, Canada, and northern Idaho and northeastern Washington, United States. We have determined that the approximately 30,010 acres (12,145 hectares) designated as critical habitat on November 28, 2012, for the southern Selkirk Mountains population of woodland caribou is applicable to the U.S. portion of the endangered southern mountain caribou DPS and, as such, reaffirm the existing critical habitat for the DPS. This rule amends the listing of this DPS on the Federal List of Endangered and Threatened Wildlife.

DATES:

This rule is effective November 1, 2019.

ADDRESSES:

This final rule is available at

http://www.regulations.gov

under Docket No. FWS-R1-ES-2012-0097, and at the Service's Idaho Fish and Wildlife Office at

http://www.fws.gov/idaho/.

Comments and materials we received, as well as supporting documentation we used in preparing this rule, are available for public inspection at

http://www.regulations.gov.

All of the comments, materials, and documentation that we considered in this rulemaking are available by appointment, during normal business hours at: U.S. Fish and Wildlife Service, Northern Idaho Field Office, 11103 E. Montgomery Drive, Spokane Valley, WA 99206; telephone 509-891-6839; facsimile 509-891-6748.

FOR FURTHER INFORMATION CONTACT:

Greg Hughes, State Supervisor, U.S. Fish and Wildlife Service, Idaho Fish and Wildlife Office, 1387 S. Vinnell Way, Room 368, Boise, ID 83709; telephone 208-378-5243; facsimile 208-378-5262. Persons who are hearing impaired or speech impaired may call the Federal Relay Service at 800-877-8339 for TTY (telephone typewriter or teletypewriter) assistance 24 hours a day, 7 days a week.

SUPPLEMENTARY INFORMATION:

Executive Summary

Why we need to publish a rule.

Under the Act, a species may warrant protection through listing if it is endangered or threatened throughout all or a significant portion of its range. Listing a species as an endangered or threatened species can only be completed by rulemaking. Any proposed or final rule designating a DPS as endangered or threatened under the Act should clearly analyze the action using the following three elements: discreteness of the population segment in relation to the remainder of the taxon to which it belongs; the significance of the population segment to the taxon to which it belongs; and the conservation status of the population segment in relation to the Act's standards for listing (DPS policy; 61 FR 4722, February 7, 1996). Under the Act, any species that is determined to be an endangered or threatened species requires critical habitat to be designated, to the maximum extent prudent and determinable. Designations and revisions of critical habitat can only be completed through rulemaking. Here we reaffirm the designation of approximately 30,010 acres (ac) (12,145 hectares (ha)) in one unit within Boundary County, Idaho, and Pend Oreille County, Washington, as critical habitat for the southern mountain caribou DPS.

This rule

amends the current listing of the southern Selkirk Mountains population of woodland caribou as follows:

• By defining the southern mountain caribou DPS, which includes the currently listed southern Selkirk Mountains population of woodland caribou;

• By designating the status of the southern mountain caribou DPS as endangered under the Act; and

• By reaffirming the designation of approximately 30,010 ac (12,145 ha) as critical habitat for the southern mountain caribou DPS.

The basis for our action.

Section 4 of the Act (16 U.S.C. 1533) and its implementing regulations (50 CFR part 424) set forth the procedures for determining whether a species meets the definition of “endangered species” or “threatened species.” The Act defines an “endangered species” as a species that is “in danger of extinction throughout all or a significant portion of its range,” and a “threatened species” as a species that is “likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.” Under the Act, a species may be determined to be an endangered species or threatened species because of any one or a combination of the five factors described in section 4(a)(1): (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; and (E) other natural or manmade factors affecting its continued existence. We have determined that threats described under factors A, C, and E pose significant threats to the continued existence of the southern mountain caribou DPS.

We listed the southern Selkirk Mountains population of woodland caribou as endangered under the Act on February 29, 1984 (49 FR 7390). According to our “Policy Regarding the Recognition of Distinct Vertebrate Population Segments Under the Endangered Species Act” (DPS policy; 61 FR 4722, February 7, 1996), the appropriate application of the policy to pre-1996 DPS listings shall be considered in our 5-year reviews of the status of the species. We conducted a DPS analysis during our 2008 5-year review, which concluded that the southern Selkirk Mountains population of woodland caribou met both the discreteness and significance elements of the DPS policy. However, we now recognize that this analysis did not consider the significance of this population relative to the appropriate taxon. The purpose of the DPS policy is to set forth standards for determining which populations of vertebrate organisms that are subsets of species or subspecies may qualify as entities that we may list as endangered or threatened under the Act. In the 2008 5-year review, we assessed the significance of the southern Selkirk Mountains

population to the “mountain ecotype” of woodland caribou. The “mountain ecotype” is neither a species nor a subspecies. The appropriate DPS analysis for the southern Selkirk Mountains population of woodland caribou should have been conducted relative to the subspecies woodland caribou (

Rangifer tarandus caribou

). Listing or reclassifying DPSs allows the Service to protect and conserve species and the ecosystems upon which they depend before large-scale decline occurs that would necessitate listing a species or subspecies throughout its entire range.

Peer review and public comment. We sought comments from independent specialists to ensure that our designation is based on scientifically sound data, assumptions, and analyses. We invited these peer reviewers to comment on our amended listing proposal. We also considered all comments and information we received during the comment period.

Summary of Changes From the Proposed Rule

Based on information we received in comments regarding how we described the coat color of caribou during breeding and winter, we modified our description to reflect that caribou coat color and pattern is variable (Geist 2007) and winter pelage varies from almost white to dark brown (see

Species Information

under Background, below).

In our May 8, 2014, proposed rule (79 FR 26504), we noted that woodland caribou populations can be further broken down into subunits called “local populations.” The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) (2014, entire) uses the term “subpopulation” to refer to the same population subunits in Canada. In order to minimize confusion, we have conformed our terminology to that used by COSEWIC. Therefore, our proposed rule uses “subpopulations,” instead of “local populations,” to describe caribou subunits.

Caribou subpopulations represent groupings of individual woodland caribou that have overlapping ranges/movement patterns and breed with one another more frequently than they breed with caribou from other subpopulations. Subpopulations in southern British Columbia are thought to be a relatively recent phenomena resulting from habitat fragmentation and loss within the population of woodland caribou; historically, movement of caribou between subpopulations was likely.

Within the Status of the Southern Mountain Caribou DPS discussion in this final rule, we provide clarification on the number and names of subpopulations (both extant and recently extirpated) within the DPS, and describe how subpopulation names and groupings of subpopulations by Canada have changed through time. We also clarify that the range of the DPS in British Columbia, Canada, and the United States has declined by 60 percent since historical arrival of Europeans in British Columbia, according to Spalding (2000, p. 40). In our May 8, 2014 proposed rule (79 FR 26504), we stated the range of the DPS had declined by 40 percent, but this was specific to the British Columbia, Canada, portion of the DPS's range (

i.e.,

it did not include the portion of the range in the United States).

We updated the status of the southern mountain caribou DPS to reflect the most recent information contained in the COSEWIC report (2014, entire) pertaining to the number of individual caribou in each of the 15 extant subpopulations and the total estimated number of individuals in the DPS. We corrected the trend status of the Hart Ranges subpopulation to reflect that it is now declining, and to reflect that the overall trend of the DPS is declining and the rate of decline is accelerating. We also included additional information pertaining to population viability analyses conducted by Hatter (2006, entire,

in litt.

) and Wittmer (2010, entire) assessing the extinction risk of subpopulations within the DPS.

We provided additional analysis pertaining to the isolation of subpopulations within the DPS as well as separation from other populations (

i.e.,

Designatable Units) of woodland caribou in Canada. We explained how this isolation may affect the ability of the subpopulations within the DPS to function as a metapopulation, which could adversely affect the demographic and/or genetic stability or rescue of subpopulations within the DPS. We also provided additional analyses on potential threats to the DPS related to renewable energy and industrial development, and effect of predation upon the current and future status of the DPS.

We included additional information pertaining to Canadian conservation efforts for woodland caribou, which include augmenting animals into the Purcells South subpopulation and wolf control efforts within several subpopulations within the DPS (under the Factor A analysis, below, see

Efforts in Canada

under “Conservation Efforts to Reduce Habitat Destruction, Modification, or Curtailment of Its Range”). We also included additional information pertaining to existing regulations enacted by the British Columbia provincial government that can be utilized to protect southern mountain caribou and their habitat, as well as implementing programs and projects for their conservation (see “Canada” under Factor D analysis, below).

In our May 8, 2014, proposed rule (79 FR 26504), we stated that further evaluation of existing regulatory mechanisms (Factor D) was needed before a final determination could be made as to the adequacy of existing regulatory mechanisms to address the threats affecting the status of the DPS. Notwithstanding the additional information learned regarding existing provincial laws and regulations of British Columbia, Canada, we conclude that, while the existing regulatory mechanisms in the United States and Canada enable the United States and Canada to ameliorate to some extent the identified threats to the southern mountain caribou DPS, the existing mechanisms do not completely alleviate the potential for the identified threats to affect the status of southern mountain caribou and their habitat.

In our May 8, 2014, proposed rule (79 FR 26504), we proposed to list the southern mountain caribou DPS as threatened. However, we have now determined that the status of, and threats to, the southern mountain caribou DPS warrant its listing as endangered. This determination is based on (1) the additional analysis referenced above and contained in the Status of the Southern Mountain Caribou DPS discussion below; and (2) the discussions of factors A (the present or threatened destruction, modification, or curtailment of its habitat or range), C (disease or predation), D (inadequacy of regulatory mechanisms) and E (other natural or manmade factors affecting its continued existence) in this final rule. The rationale for endangered status is summarized within the Determination section of this final rule. The May 8, 2014, proposed rule also contained a “Significant Portion of the Range” (SPR) analysis. That analysis was included in the proposed rule to conform to Service policy for listing rules at that time. However, subsequent to publishing the proposed rule, the Service revised its policy on when it is necessary to perform a SPR analysis (79 FR 37578, July 1, 2014).

In this case, because we found that the southern mountain DPS of woodland caribou is in danger of extinction throughout all of its range, per the Service's SPR Policy (79 FR 37578, July 1, 2014), the protections of the Act apply to each individual

member of the DPS wherever found. Consequently, an analysis of whether there is any significant portion of its range where the species is in danger of extinction or likely to become so in the foreseeable future was unnecessary and was not conducted.

Background

Previous Federal Actions

Please refer to the proposed amended listing rule for the southern mountain caribou DPS (79 FR 26504; May 8, 2014) for a detailed description of previous Federal actions concerning this species. The May 8, 2014, proposed rule opened a 60-day public comment period, ending July 7, 2014. On June 10, 2014, we extended the public comment period on the proposed amended listing rule until August 6, 2014, and announced two public informational sessions and hearings (79 FR 33169). Public informational sessions and hearings were held in Sandpoint, Idaho, on June 25, 2014, and in Bonners Ferry, Idaho, on June 26, 2014 (79 FR 33169). On March 24, 2015, we reopened the public comment period on the proposed amended listing rule for an additional 30 days, ending on April 23, 2015, to allow the public time to review new information: A report from COSEWIC

1

and associated literature, which we received after the previous public comment period (80 FR 15545).

1

A list of acronyms used in this document is available at

http://www.regulations.gov

under Docket No. FWS-R1-ES-2012-0097.

In our May 8, 2014, proposed rule (79 FR 26504), we proposed to reaffirm the November 28, 2012, final critical habitat designation (77 FR 71042) for the southern Selkirk Mountains population of woodland caribou as it applies to the U.S. portion of the endangered southern mountain DPS of woodland caribou. However, on March 23, 2015, the Idaho District Court (

Center for Biological Diversity

v.

Kelly,

93 F.Supp.3d 1193 (D. Idaho, 2015)) ruled that we made a procedural error in not providing public review and comment regarding considerations we made related to our final critical habitat designation (77 FR 71042). On April 19, 2016, in response to the court's order, we published a document in the

Federal Register

(81 FR 22961) that reopened the public comment period on the November 28, 2012, final designation of critical habitat (77 FR 71042), which we proposed to reaffirm in the May 8, 2014, proposed rule (79 FR 26504) as the critical habitat for the southern mountain caribou DPS. We received numerous comments regarding critical habitat during the initial public comment periods for the proposed amended listing rule; we are addressing those comments in this final rule as well as new comments we received during the reopened public comment period on the November 28, 2012, final critical habitat designation.

Species Information

Please refer to the proposed listing rule for the southern mountain caribou DPS (79 FR 26504; May 8, 2014) for a summary of species information. Except for the following correction, there are no changes to the species information provided in that proposed rule. The sentence reading, “Their winter pelage varies from nearly white in Arctic caribou such as the Peary caribou, to dark brown in woodland caribou (COSEWIC 2011, pp. 10-11)” at 79 FR 26507 should instead read, “Breeding pelage is variable in color and patterning (Geist 2007), and winter pelage varies from almost white to dark brown.”

Evaluation of the Southern Mountain Caribou as a Distinct Population Segment

Introduction and Background

The National Marine Fisheries Service (NMFS) and the Service published a joint “Policy Regarding the Recognition of Distinct Vertebrate Population Segments Under the Endangered Species Act” (DPS Policy) on February 7, 1996 (61 FR 4722). According to the DPS policy, any proposed or final rule designating a DPS as endangered or threatened under the Act should clearly analyze the action using the following three elements: Discreteness of the population segment in relation to the remainder of the taxon to which it belongs; the significance of the population segment to the taxon to which it belongs; and the conservation status of the population segment in relation to the Act's standards for listing. If the population segment qualifies as a DPS, the conservation status of that DPS is then evaluated to determine whether it is endangered or threatened.

A population segment of a vertebrate species may be considered discrete if it satisfies either one of the following conditions: (1) It is markedly separated from other populations of the same taxon as a consequence of physical, physiological, ecological, or behavioral factors; or (2) it is delimited by international governmental boundaries within which differences in control of exploitation, management of habitat, conservation status, or regulatory mechanisms exist that are significant in light of section 4(a)(1)(D) of the Act.

If a population is found to be discrete, then it is evaluated for significance under the DPS policy on the basis of its importance to the taxon to which it belongs. This consideration may include, but is not limited to, the following: (1) Persistence of the discrete population segment in an ecological setting unusual or unique to the taxon; (2) evidence that loss of the discrete population segment would result in a significant gap in the range of the taxon; (3) evidence that the population represents the only surviving natural occurrence of the taxon that may be more abundant elsewhere as an introduced population outside of its historical range; or (4) evidence that the population differs markedly from other populations of the species in its genetic characteristics.

If a population segment is both discrete

and

significant (

i.e.,

it qualifies as a potential DPS), its evaluation for endangered or threatened status is based on the Act's definitions of those terms and a review of the factors listed in section 4(a) of the Act. According to our DPS policy, it may be appropriate to assign different classifications to different DPSs of the same vertebrate taxon.

Section 3(16) of the Act defines the term “species” to include “any subspecies of fish or wildlife or plants, and any distinct population segment of any species of vertebrate fish or wildlife which interbreeds when mature.” We have always understood the phrase “interbreeds when mature” to mean that a DPS must consist of members of the same species or subspecies in the wild that would be biologically capable of interbreeding if given the opportunity, but all members need not actually interbreed with each other. A DPS is a subset of a species or subspecies, and cannot consist of members of a different species or subspecies. A DPS may include multiple populations of vertebrate organisms that may not necessarily interbreed with each other. For example, a DPS may consist of multiple populations of a fish species separated into different drainages. While these populations may not actually interbreed with each other, their members are biologically capable of interbreeding.

Distinctive, discrete, and significant populations of the woodland caribou have been identified, described, and assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). COSEWIC is composed of qualified wildlife experts drawn from Federal, provincial, and territorial governments; wildlife management boards; Aboriginal groups; universities;

museums; national nongovernmental organizations; and others with expertise in the conservation of wildlife species in Canada. The role of COSEWIC is to assess and classify, using the best available information, the conservation status of wildlife species, subspecies, and separate populations suspected of being at risk. In addition, they make species status recommendations to the Canadian government and the public. Once COSEWIC makes this recommendation, it is the option of the Canadian Federal government to decide whether a species will be listed under Canada's Species At Risk Act (SARA). The southern mountain caribou population, which includes the transboundary southern Selkirk Mountains population of woodland caribou (and is the subject of this final amended listing), is currently designated as “threatened” under SARA (COSEWIC 2011, p. 74). This designation was reached because the population of southern mountain caribou is mostly made up of small, increasingly isolated herds (most of which are in decline) with an estimated range reduction of up to 40 percent from their historical range (COSEWIC 2002, p. 58; COSEWIC 2011, p. 74).

In August 2014, COSEWIC, in accordance with SARA, submitted its assessment to the Canadian Federal Environment Minister for consideration of changing the legal status of the southern mountain caribou in Canada under SARA to endangered (COSEWIC 2014, p. iv). The recommended change in the legal status under SARA is pending review and decision by the Federal Environment Minister.

Because we now consider the southern Selkirk Mountains population of woodland caribou part of the larger southern mountain caribou population, as recognized by COSEWIC (2011, entire), we recognize that our evaluation of the southern Selkirk Mountains population is more appropriately conducted at the scale of the larger southern mountain caribou population. Therefore, below we evaluate whether, under our DPS policy, the southern mountain caribou population segment (

i.e.,

15 extant and 2 extirpated subpopulations) of woodland caribou occurring in British Columbia, Canada, and northeastern Washington and northern Idaho, United States, qualifies as a DPS under the Act.

We completed a 5-year review of the endangered southern Selkirk Mountains population of woodland caribou (

Rangifer tarandus caribou

) in 2008 (USFWS 2008). Because this population was listed prior to the Service's 1996 DPS policy (61 FR 4722; February 7, 1996), the 5-year review included an analysis of this population in relation to the DPS policy. In conducting the DPS analysis, we considered the discreteness and significance of this population in relation to the mountain caribou metapopulation (USFWS 2008, pp. 6-13) (

i.e.,

mountain caribou ecotype). From this analysis, we concluded that the southern Selkirk Mountains population of woodland caribou met both the discreteness and significance elements of the DPS policy and was a distinct population segment of the mountain caribou metapopulation (USFWS 2008, p. 13). However, we acknowledged in our December 19, 2012, 90-day finding (77 FR 75091) on a petition to delist the southern Selkirk Mountains population of woodland caribou that the DPS analysis in our 2008 5-year review was not conducted relative to the appropriate taxon. Specifically, we should have conducted the DPS analysis of the southern Selkirk Mountains population of woodland caribou relative to the woodland caribou subspecies (

Rangifer tarandus caribou

) instead of the mountain caribou metapopulation.

For this final amended listing and DPS analysis of the southern mountain population of woodland caribou to the subspecies woodland caribou, we reviewed and evaluated information contained in numerous publications and reports, including, but not limited to: Banfield 1961; Stevenson

et al.

2001; COSEWIC 2002, 2011, 2014; Cichowski

et al.

2004; Wittmer

et al.

2005b, 2010; Hatter 2006,

in litt.;

Geist 2007; van Oort

et al.

2011; and Serrouya

et al.

2012.

In 2002 and 2011, COSEWIC completed status assessments of caribou subspecies and species populations in North America. The 2002 COSEWIC Report evaluated woodland caribou “nationally significant populations” (NSPs). The more recent COSEWIC (2011) Report described “Designatable Units” (DUs) as the appropriate “discrete and significant units” useful to conserve and manage caribou populations throughout Canada. Information used in COSEWIC's 2011 report is useful to our DPS analysis. Canada's DUs are identified based on the criteria that there are “discrete and evolutionarily significant units of a taxonomic species, where `significant' means that the unit is important to the evolutionary legacy of the species as a whole and if lost, would likely not be replaced through natural dispersion” (COSEWIC 2011, p. 14). They consider a population or group of populations to be “discrete” based on the following criteria: distinctiveness in genetic characteristics or inherited traits, habitat discontinuity, or ecological isolation (COSEWIC 2011, p. 15).

It should be noted that COSEWIC's DU designation does not necessarily consider the conservation status or threats to the persistence of caribou DUs. Consistent with its 2009 guidelines, the COSEWIC used five lines of evidence to determine caribou DUs; these include: (1) Phylogenetics; (2) genetic diversity and structure; (3) morphology; (4) movements, behavior, and life-history strategies; and (5) distribution (COSEWIC 2011, p. 15). As a general rule, a DU was designated when several lines of evidence provided support for discreteness and significance (COSEWIC 2011, pp. 15-16). Twelve caribou DUs were classified by COSEWIC in 2011, including the southern mountain caribou population (DU9), which includes the southern Selkirk Mountains population of woodland caribou (COSEWIC 2011, p. 21). The information used to describe the southern mountain DU is reviewed and evaluated in our DPS analysis, as it includes numerous local woodland caribou populations that all possess similar and unique foraging, migration, and habitat use behaviors, and that are geographically separated from other caribou DUs.

Discreteness

As outlined in our 1996 DPS policy, a population segment of a vertebrate species may be considered discrete if it satisfies either one of the following conditions: (1) It is markedly separated from other populations of the same taxon as a consequence of physical, physiological, ecological, or behavioral factors; or (2) it is delimited by international governmental boundaries within which differences in control of exploitation, management of habitat, conservation status, or regulatory mechanisms exist that are significant in light of section 4(a)(1)(D) of the Act.

I. Physical (Geographic) Discreteness

The southern Selkirk Mountains population of woodland caribou is 1 of 17 woodland caribou subpopulations (15 extant, 2 extirpated) (COSEWIC 2014, p. xix) that share distinct foraging, migration, and habitat use behaviors. These subpopulations are all located in steep, mountainous terrain in central and southeastern British Columbia, Canada, and in extreme northeastern Washington and northern Idaho, United States. Little to no dispersal has been detected between these subpopulations and other caribou populations/subpopulations outside this geographic area (Wittmer

et al.

2005b, pp. 408, 409; COSEWIC 2011, p. 49; van Oort

et al.

2011, pp. 222-223), indicating that mountain caribou appear to lack the inherent behavior to disperse long distances (van Oort,

et al.

2011, pp. 215, 221-222). For the purposes of this DPS analysis, this collection of woodland caribou subpopulations, which, as noted above, includes the southern Selkirk Mountains population, constitutes the southern mountain population of caribou; we also refer to it herein as “southern mountain caribou.”

Telemetry research by Wittmer

et al.

(2005b) and van Oort

et al.

(2011) supports the physical (geographic) discreteness of southern mountain caribou. One exception is that there is some limited annual range overlap between a few local caribou populations at the far north of the southern mountain caribou population. Although all caribou and reindeer worldwide are considered to be the same species (

Rangifer tarandus

) and are presumed able to interbreed and produce offspring (COSEWIC 2002, p. 9), the distribution of the southern mountain caribou does not overlap with other caribou populations during the rut or mating season (COSEWIC 2011, p. 50). Previous telemetry studies were completed by Apps and McLellan (2006, pp. 84-85, 92) to determine occupancy across differing landscapes. These studies confirmed that woodland caribou within the geographic area that defines the southern mountain caribou population are strongly associated with the steep, mountainous terrain characterizing the “interior wet-belt” of British Columbia (Stevenson

et al.

2001, p. 3), located west of the continental divide. This area is influenced by Pacific air masses that produce the wettest climate in the interior of British Columbia (Stevenson

et al.

2001, p. 3). Forests consist of Engelmann spruce (

Picea engelmannii

or

P. glauca

x

engelmannii

)/subalpine fir (

Abies lasiocarpa

) at high elevation, and western red cedar (

Thuja plicata

)/western hemlock (

Tsuga heterophylla

) at lower elevations. Snowpack typically averages 5 to 16 feet (ft) (2 to 5 meters (m)) in depth (Stevenson

et al.

2001, p. 4; COSEWIC 2011, p. 50). Apps and McLellan (2006, p. 92) noted that the steep, complex topography within the interior wet-belt provides seasonally important habitats. Caribou access this habitat by migrating in elevational shifts rather than through the long horizontal migrations of other subspecies in northern Canada. Woodland caribou that live within this interior wet-belt of southern British Columbia, northeastern Washington, and northern Idaho are strongly associated with old-growth forested landscapes (Apps

et al.

2001, pp. 65, 70). These landscapes are predominantly cedar/hemlock and spruce/subalpine fir composition (Stevenson

et al.

2001, pp. 3-5; Apps and McLellan 2006, pp. 84, 91; Cichowski

et al.

2004, pp. 224, 231; COSEWIC 2011, p. 50) that supports woodland caribou's late-winter diet consisting almost entirely of arboreal hair lichens (Cichowski

et al.

2004, p. 229).

The southern mountain caribou population is markedly separate from other populations of woodland caribou as a result of physical (geographic) factors. The distribution of this population is primarily located within the interior wet-belt of southern British Columbia, occurring west of the continental divide and generally south of Reynolds Creek (which is about 90 miles (mi) (150 kilometers (km)) north of Prince George, British Columbia). Its geographic range is such that it does not reproduce with other subpopulations of woodland caribou.

II. Behavioral Discreteness

In addition to being physically (geographically) discrete, individuals within the southern mountain caribou population are behaviorally distinguished from woodland caribou in other populations (including the neighboring Northern Mountain and Central Mountain populations). Southern mountain caribou uniquely use steep, high-elevation, mountainous habitats with deep snowfall (about 5 to 16 ft (2 to 5 m)) (COSEWIC 2011, p. 50), and, as described below, are the only woodland caribou that depend on arboreal lichens for forage. This habitat use contrasts with the behavior of other woodland caribou, which occupy relatively drier habitats that receive less snowfall. With less snowfall in these areas, these woodland caribou primarily forage on terrestrial lichens, accessing them by “cratering” or digging through the snow with their hooves (Thomas

et al.

1996, p. 339; COSEWIC 2002, pp. 25, 27).

Extreme, deep snow conditions have led to a foraging strategy by the southern mountain caribou that is unique among woodland caribou. They rely exclusively on arboreal (tree) lichens for 3 or more months of the year (Servheen and Lyon 1989, p. 235; Edmonds 1991, p. 91; Stevenson

et al.

2001, p. 1; Cichowski

et al.

2004, pp. 224, 230-231; MCST 2005, p. 2; COSEWIC 2011, p. 50). Arboreal lichens are a critical winter food for the southern mountain caribou from November to May (Servheen and Lyon 1989, p. 235; Stevenson

et al.

2001, p. 1; Cichowski

et al.

2004, p. 233). During this time, a southern mountain caribou's diet can be composed almost entirely of these lichens. Arboreal lichens are pulled from the branches of conifers, picked from the surface of the snow after being blown out of trees by wind, or are grazed from wind-thrown branches and trees. The two kinds of arboreal lichens commonly eaten by the southern mountain caribou are

Bryoria

spp. and

Alectoria sarmentosa.

Both are extremely slow-growing lichens most commonly found in high-elevation, old-growth conifer forests that are greater than 250 years old (Paquet 1997, p. 14; Apps

et al.

2001, pp. 65-66).

Another unique behavior of caribou within the southern mountain caribou population is their altitudinal migrations. They may undertake as many as four of these migrations per year (COSEWIC 2011, p. 50). After wintering at high elevations as described above, at the onset of spring, these caribou move to lower elevations where snow has melted to forage on new green vegetation (Paquet 1997, p. 16; Mountain Caribou Technical Advisory Committee (MCTAC) 2002, p. 11). Pregnant females will move to these spring habitats for forage. During the calving season, sometime from June into July, the need to avoid predators influences habitat selection. Areas selected for calving are typically high-elevation, alpine and non-forested areas in close proximity to old-growth forest ridge tops, as well as high-elevation basins. These high-elevation sites can be food limited, but are more likely to be free of predators (USFWS 1994a, p. 8; MCTAC 2002, p. 11; Cichowski

et al.

2004, p. 232; Kinley and Apps 2007, p. 16). During calving, arboreal lichens become the primary food source for pregnant females at these elevations. This is because green forage is largely unavailable in these secluded, old-growth conifer habitats.

During summer months, southern mountain caribou move back to upper-elevation spruce/alpine fir forests (Paquet 1997, p. 16). Summer diets include selective foraging of grasses, flowering plants, horsetails, willow and dwarf birch leaves and tips, sedges, lichens (Paquet 1997, pp. 13, 16), and huckleberry leaves (U.S. Forest Service (USFS) 2004, p. 18). The fall and early winter diet consists largely of dried grasses, sedges, willow and dwarf birch tips, and arboreal lichens.

The southern mountain caribou are behaviorally adapted to the steep, high-elevation, mountainous habitat with deep snowpack. They feed almost exclusively on arboreal lichens for 3 or more months out of the year. They are

also reproductively isolated, due to their behavior and separation from other caribou populations during the fall rut and mating season (COSEWIC 2011, p. 50). Based on these unique adaptations, we consider the southern mountain caribou population to meet the behavioral “discreteness” standard in our DPS policy.

III. Genetic Discreteness

Data from Serrouya

et al.

(2012, p. 2,594) show that genetic population structure (

i.e.,

patterning or clustering of the genetic make-up of individuals within a population) does exist within woodland caribou. Specifically, Serrouya revealed a genetic cluster that is unique to southern mountain caribou and different from genetic clusters found in surrounding subpopulations of woodland caribou designated as part of other Canada caribou DUs (

i.e.,

Central Mountain DU, Northern Mountain DU, and Boreal DU). However, Serrouya also revealed genetic clusters that occur in both the southern mountain caribou and neighboring DUs that suggest some historical gene flow did occur in the past, meaning that historically, caribou moved between populations of these DUs and interbred when mature.

This cluster overlap of DU boundaries is not surprising, as genetic structure is reflective of long-term historical population dynamics and does not necessarily depict current gene flow. Indeed, it does appear that recent impediments to gene flow may be genetically isolating woodland caribou in the southwest portion of their range (Wittmer

et al.

2005b, p. 414; van Oort

et al.

2011, p. 221; Serrouya

et al.

2012, p. 2,598). These impediments include anthropogenic habitat fragmentation and widespread caribou population declines. Therefore, genetic specialization related to unique behaviors and habitat use may represent a relatively recent life-history characteristic (Weckworth

et al.

2012, p. 3,620). Historical gene flow between subpopulations of southern mountain caribou and neighboring subpopulations did occur in the past. However, study results from Serrouya

et al.

(2012), combined with telemetry data from Wittmer

et al.

(2005b, p. 414) and van Oort

et al.

(2011, p. 221), suggest that isolation of subpopulations is now the norm, effecting some genetic differentiation of these subpopulations through genetic drift (Serrouya

et al.

2012, p. 2,597).

A certain level of genetic differentiation does exist between the southern mountain caribou population and neighboring woodland caribou. However, we do not presently consider there to be sufficient evidence to determine that the southern mountain caribou are genetically isolated from other populations of caribou, particularly the Central Mountain population. Therefore, at this time, we do not find that this population meets the genetic “discreteness” standard in our DPS policy.

IV. Discreteness Conclusion

In summary, we determine that the best available information indicates that the southern mountain caribou, comprised of 17 woodland caribou subpopulations (15 extant and 2 extirpated) that occur in southern British Columbia, northeastern Washington, and northern Idaho, is markedly separated from all other populations of woodland caribou. The southern mountain caribou population is physically (geographically), behaviorally, and reproductively isolated from other woodland caribou. Therefore, we consider the southern mountain caribou population to be discrete per our DPS policy.

Significance

Under our DPS policy, once we have determined that a population segment is discrete, we consider its biological and ecological significance to the larger taxon to which it belongs. Significance is not determined by a quantitative analysis, but is instead a qualitative finding. It will vary from species to species and cannot be reduced to a simple formula or flat percentage. Our DPS policy provides several potential considerations that may demonstrate the significance of a population segment to the species to which it belongs. These considerations include, but are not limited to: (1) Persistence of the discrete population segment in an ecological setting unusual or unique for the taxon; (2) evidence that the discrete population segment differs markedly from other population segments in its genetic characteristics; (3) evidence that the population segment represents the only surviving natural occurrence of the taxon that may be more abundant elsewhere as an introduced population outside its historical range; and (4) evidence that loss of the discrete population segment would result in a significant gap in the range of the taxon. The following discussion addresses considerations regarding the significance of the southern mountain caribou population to the subspecies woodland caribou (

Rangifer tarandus caribou

).

I. Persistence of the Discrete Population Segment in an Ecological Setting Unusual or Unique for the Taxon

As previously discussed, woodland caribou within the southern mountain caribou population are distinguished from woodland caribou in other areas. Southern mountain caribou live in, and are behaviorally adapted to, a unique ecological setting characterized by high-elevation, high-precipitation, and steep old-growth conifer forests that support abundant arboreal lichens (COSEWIC 2011, p. 50). In addition, all woodland caribou in the southern mountain caribou population exhibit a distinct behavior. Specifically, they spend the winter months in high-elevation, steep, mountainous habitats where individuals stand on the deep, hard-crusted snowpack and feed exclusively on arboreal lichens on standing or fallen old-growth conifer trees (Cichowski

et al.

2004, pp. 224, 230-231; MCST 2005, p. 2; COSEWIC 2011, p. 50). This behavior is unlike that of woodland caribou in neighboring areas that occupy less steep, drier terrain and do not feed on arboreal lichens during the winter (Thomas

et al.

1996, p. 339; COSEWIC 2011, p. 50).

In addition to persisting in a specific environment characterized by steep, high-elevation, old-growth forests and being reliant on arboreal lichens as primary winter forage, caribou of the southern mountain population make relatively short-distance altitudinal migrations up to four times per year. These caribou occupy valley bottoms and lower slopes in the early winter, and ridge tops and upper slopes in later winter after the snowpack deepens and hardens. In the spring, they move to lower elevations again to access green vegetation. Females make solitary movements back to high elevations to calve. This habitat and behavior are unique to the southern mountain caribou population. All other populations within the woodland caribou subspecies occupy winter habitat characterized by gentler topography, lower elevation, and less winter snowpack (COSEWIC 2011, pp. 43, 46) where their primary winter forage, terrestrial (ground) lichens, is most accessible (Thomas

et al.

1996, p. 339; COSEWIC 2011, pp. 43, 46). Unlike woodland caribou of the southern mountain population, some populations in eastern Canada (Eastern Migratory DU (DU4; COSEWIC 2011, p. 34)) will migrate relatively long distances across the landscape between wintering and calving habitat, where they will calve in large aggregated groups (COSEWIC

2011, pp., 33, 37; Abraham

et al.

2012, p. 274).

We conclude that the southern mountain caribou meets the definition of significant in accordance with our DPS policy, as this population currently persists in an ecological setting unusual or unique for the subspecies of woodland caribou.

II. Evidence That the Discrete Population Segment Differs Markedly From Other Population Segments in Its Genetic Characteristics

Research by Serrouya

et al.

(2012, p. 2594) indicates that there is some genetic population structure between woodland caribou populations in western North America. This research identified two main genetic clusters within the southern mountain caribou, separated from each other by the North Thompson Valley in British Columbia. One of these clusters is unique, with few exceptions, to the southern mountain caribou (structure analysis; Serrouya

et al.

2012, p. 2594). The other cluster, northwest of the North Thompson Valley, is shared with the adjacent Central Mountain population. As such, there is limited genetic evidence in this study that southern mountain caribou populations north of the North Thompson Valley are genetically unique relative to caribou of the Central Mountain population.

As previously discussed, the best available information indicates that recent impediments to gene flow such as habitat fragmentation and widespread caribou population declines may be genetically isolating woodland caribou in the southwestern portion of their range (Wittmer

et al.

2005b, p. 414; van Oort

et al.

2011, p. 221; Serrouya

et al.

2012, p. 2,598). This genetic isolation has resulted in unique behaviors and habitat use (Weckworth

et al.

2012, p. 3,620). Study results from Serrouya

et al.

(2012), combined with telemetry data from Wittmer

et al.

(2005b, p. 414) and van Oort

et al.

(2011, p. 221), suggest that while historical gene flow between subpopulations of southern mountain caribou and neighboring subpopulations did occur in the past, isolation of these subpopulations is now the norm. Research into the genetics of the woodland caribou will likely continue and will provide further insight into gene flow between these populations.

Despite some level of genetic differentiation between the southern mountain caribou population and neighboring woodland caribou, and a predicted continuation of genetic differentiation between subpopulations within southern mountain caribou, we do not presently consider southern mountain caribou “genetically unique.” Therefore, at this time we do not find this population meets the genetic “significance” standard in our DPS policy.

III. Evidence That the Population Segment Represents the Only Surviving Natural Occurrence of a Taxon That May Be More Abundant Elsewhere as an Introduced Population Outside Its Historic Range

All caribou in the world are one species (

Rangifer tarandus

). In a global review of taxonomy of the genus

Rangifer,

Banfield (1961) documented the occurrence of five subspecies in North America. Woodland caribou (

Rangifer tarandus caribou

), one of the five recognized subspecies of caribou, are the southern-most subspecies in North America. The range of woodland caribou extends in an east/west band from eastern Newfoundland and northern Quebec, all the way into western British Columbia. Southern mountain caribou represent a discrete subset of this subspecies. Because southern mountain caribou are not the only surviving natural occurrence of the woodland caribou subspecies, this element is not applicable.

IV. Evidence That Loss of the Discrete Population Segment Would Result in a Significant Gap in the Range of the Taxon

Historically, woodland caribou were widely distributed throughout portions of the northern tier of the coterminous United States from Washington to Maine, as well as throughout most of southern Canada (COSEWIC 2002, p. 19). However, as a result of habitat loss and fragmentation, overhunting, and the effects of predation, the population of woodland caribou within the British Columbia portion of their range has declined dramatically with an estimated 40 percent range reduction (COSEWIC 2002, p. 20). Additionally, Hatter (pers. comm. as cited in Spalding 2000, p. 40) estimated that the range of southern mountain caribou has declined by approximately 60 percent, when considering both the Canadian and U.S. range of the population. However, because there are no reliable historical estimates of the number of southern mountain caribou and their distribution (Spalding 2000, p. 34), it is difficult to precisely estimate their historical range for a comparison to their current range. Nevertheless, according to COSEWIC (2014, p. 14), mountain caribou were much more widely distributed than they are today, and thus the range of this population is decreasing. Further evidence of this decline is supported by population surveys. For example, Hatter

et al.

(2004, p. 7) reported there were an estimated 2,554 individuals in the population in 1995, but in 2014, COSEWIC (2014, p. xvii) estimated the number of caribou in this population has declined to only 1,356 individuals.

Loss of the southern mountain caribou population would result in the loss of the southern-most extent of the range of woodland caribou by about 2.5 degrees of latitude. The Service has not established a threshold of degrees latitude loss or percent range reduction for determining significance to a particular taxon. The importance of specific degrees latitude loss and/or percent range reduction, and the analysis of what such loss or reduction ultimately means to conservation of individual species/subspecies necessarily will be specific to the biology of the species/subspecies in question. However, the extirpation of peripheral populations, such as the southern mountain caribou population, is concerning because of the potential conservation value that peripheral populations can provide to a species or subspecies. Specifically, peripheral populations can possess slight genetic or phenotypic divergences from core populations (Lesica and Allendorf 1995, p. 756; Fraser 2000, p. 50). The genotypic and phenotypic characteristics peripheral populations may provide to the core population of the species may be central to the species' survival in the face of environmental change (Lesica and Allendorf 1995, p. 756; Bunnell

et al.

2004, p. 2,242). Additionally, data tend to show that peripheral populations are persistent when species' range collapse occurs (Lomolino and Channell 1995, p. 342; Channell and Lomolino 2000, pp. 84-86; Channell 2004, p. 1). Of 96 species whose last remnant populations were found either in core or periphery of the historical range (rather than some in both core and periphery), 91 (95 percent) of the species were found to exist only in the periphery, and 5 (5 percent) existed solely in the center (Channell and Lomolino 2000, p. 85). Also, as described previously, caribou within the southern mountain population occur at the southern edge of woodland caribou range (

i.e.,

they are a peripheral population), and have adapted to an environment unique to woodland caribou. Peripheral populations adapted to different environments may facilitate speciation (Mayr 1970 in Channell 2004, p. 9). Thus, the available scientific literature data support the importance of peripheral populations for conservation

(Fraser 2000, entire; Lesica and Allendorf, 1995, entire).

Additionally, loss of the southern mountain caribou population would result in the loss of the only remaining population of the woodland caribou in the coterminous United States. An additional consequence of the loss of the southern mountain caribou population would be the elimination of the only North American caribou population with the distinct behavior of feeding exclusively on arboreal lichens for 3 or more months of the year. This feeding behavior is related to their spending winter months in high-elevation, steep, mountainous habitats with deep snowpack.

Finally, extirpation of this population segment would result in the loss of a peripheral population segment of woodland caribou that live in, and are behaviorally adapted to, a unique ecological setting characterized by high-elevation, high-precipitation (including deep snowpack), and steep old-growth conifer forests that support abundant arboreal lichens.

V. Significance Conclusion

We conclude that the southern mountain caribou persists in an ecological setting unusual or unique for the subspecies of woodland caribou, and that loss of the southern mountain caribou would result in a significant gap in the range of the woodland caribou subspecies. Therefore, the discrete southern mountain caribou population of woodland caribou that occur in southern British Columbia and in northeastern Washington and northern Idaho meets significance criteria under our DPS policy.

Listable Entity Determination

In conclusion, the Service finds that the southern mountain caribou population meets both the discreteness and significance elements of our DPS policy. It qualifies as discrete because of its marked physical (geographic) and behavioral separation from other populations of the woodland caribou subspecies. It qualifies as significant because of its existence in a unique ecological setting, and because the loss of this population would leave a significant gap in the range of the woodland caribou subspecies. For consistency, we will refer to the southern mountain DU, described by COSEWIC, as the southern mountain caribou DPS. See Figure 1 for a map of the known distribution of subpopulations within the southern mountain caribou DPS.

BILLING CODE 4333-15-P

ER02OC19.000

Status of the Southern Mountain Caribou DPS

As described previously, because there are no reliable historical estimates of the number of southern mountain caribou and their distribution (Spalding 2000, p. 34), it is difficult to precisely estimate their historical range for a comparison to their current range. Nevertheless, according to COSEWIC (2014, p. 14), mountain caribou were much more widely distributed than they are today, and thus the range of this population is decreasing. Further evidence of this decline is supported by population surveys. For example, surveys of the southern mountain caribou population in 1995 estimated there were 2,554 individuals in the population (Hatter

et al.

2004, p. 7), but in 2014, COSEWIC estimated the number of caribou in this population has declined to only 1,356 individuals (COSWEIC 2014, p. xvii). The status (increasing, declining) of each subpopulation and current population estimate is identified in Table 1.

ER02OC19.001

ER02OC19.002

BILLING CODE 4333-15-C

Currently the southern mountain caribou DPS is composed of 17 subpopulations (15 extant, 2 extirpated) (Figure 1, above). However, Canada has, over time, grouped its caribou populations in accordance with various assessments (COSEWIC 2002, entire; COSEWIC 2011, entire), which has resulted in shifting boundaries, and moving one or more subpopulations between differing geographic groupings of populations. In addition to altering boundaries between populations, some subpopulation boundaries within the populations have changed as well (

e.g.,

some subpopulations have been combined). Thus, the number of subpopulations within the populations has changed. For example, the Allan Creek subpopulation listed in Hatter (2006,

in litt.

) was grouped with the Wells Gray subpopulation in COSEWIC (2014), and the Kinbasket-South subpopulation listed in Hatter (2006,

in litt.

) was renamed to Central Rockies subpopulation in COSEWIC (2014) (Ray 2014, pers. comm.). Additionally, the north and south Wells Gray subpopulations referred to in COSEWIC (2002, p. 92) were combined into a single Wells Gray subpopulation in COSEWIC's 2011 Designatable Unit Report (COSEWIC 2011, p. 89). However, the number (17) of subpopulations (which includes 15 extant and 2 recently extirpated subpopulations) and their names encompassed within the southern mountain caribou DPS conforms to Canada's southern mountain (DU9) as identified pursuant to COSEWIC (2011, entire).

All 15 extant subpopulations consist of fewer than 400 individuals each, 13 of which have fewer than 250 individuals, and 9 of which have fewer than 50 individuals (COSEWIC 2014, p. xviii). Fourteen of the 15 extant subpopulations within this DPS have declined since the last assessment by COSEWIC in 2002 (COSEWIC 2014, p. vii). Based on COSEWIC (2014, p. vii), which is new information received after we published our proposed amended listing rule (79 FR 26504; May 8, 2014), the population has declined by at least 45 percent over the last 27 years (3 generations), 40 percent over the last 18 years (2 generations), and 27 percent since the last assessment by COSEWIC in 2002 (roughly 1.4 generations) (COSEWIC 2014, p. vii). These subpopulations are continuing to suffer declines in numbers and range and have become increasingly isolated. Only one subpopulation has increased in numbers (likely due to aggressive wolf control and management) but still consists of fewer than 100 individuals; the most recent estimate was 78 individuals (COSEWIC 2014, p. 43). Given the data cited above, the rate of population decline is accelerating. The accelerated rate of population decline is supported by Wittmer

et al.

(2005b, p. 265), who studied rates and causes of southern mountain caribou population declines from 1984 to 2002 and found an increasing rate of decline.

Because subpopulation names and boundaries have changed over time, it is difficult to precisely compare subpopulation estimates for some subpopulations within the southern mountain caribou DPS over time. However, according to Wittmer

et al.

(2005b, p. 413), individual subpopulations have decreased by up to 18 percent per year (Wittmer

et al.

2005b, p. 413). For example, the Purcells South subpopulation, which is located above the Montana border, had an estimated 100 individuals in 1982, and only 20 in 2002. According to COSEWIC, this subpopulation had increased to 22 individuals in 2014 (COSEWIC 2104, p. xviii). Even though this subpopulation has slightly increased, it remains depressed.

Additionally, our May 8, 2014, proposed rule (79 FR 26504) stated that the Wells Gray South subpopulation was considered stable at 325 to 350 caribou from 1995 to 2002 (see 79 FR 26514). These numbers were obtained from Hatter

et al.

(2004, p. 7). However, according to COSEWIC's 2002 status report the subpopulation was estimated at 315 individuals and considered to be in decline (COSEWIC 2002, p. 92). Furthermore, as noted previously, COSEWIC has combined the north and south Wells Gray subpopulations (COSEWIC 2011, p. 89). According to COSEWIC, in 2002, the Wells Gray North subpopulation was estimated at 200 individuals and considered stable. Thus, the COSEWIC (2002) estimate for the combined Wells Gray subpopulation (

i.e.,

north and south subpopulations) was 515 individuals (COSEWIC 2002, p. 92). According to COSEWIC's latest assessment, the Wells Gray subpopulation is estimated at 341 individuals and considered to be declining (COSEWIC 2014, p. 41). Also, in our May 8, 2014, proposed rule (79 FR 26504), we stated that subpopulations in the northern-most portion of the DPS's range were stable (principally the Hart Ranges subpopulation with an estimated 500 individuals in 2005) (see 79 FR 26515). However, according to COSEWIC's latest status assessment, both the Hart Ranges and North Caribou Mountains subpopulations, which are both located at the northern end of this DPS's range, are declining, with population estimates of 398 and 202 caribou, respectively (COSEWIC 2014, p. 41).

Surveys of the subpopulations in the southern mountain caribou DPS estimated that, in 1995, the entire population was approximately 2,554 individuals (Hatter

et al.

2004, p. 7). By 2002, this number had decreased to approximately 1,900 individuals (Hatter

et al.

2004, p. 7). Currently, the population is estimated to be 1,356 individuals (COSEWIC 2014, p. xvii). Many subpopulations within the southern mountain caribou DPS are reported to have experienced declines of 50 percent or greater between 1995 and 2002 (MCST 2005, p. 1). Some of the most extreme decreases were observed in the Central Selkirk and Purcells South subpopulations. These subpopulations experienced 61 and 78 percent reductions in their populations, respectively, during this time (Harding 2008, p. 3).

Population models indicate declines will continue into the future for the entire southern mountain caribou DPS and for many subpopulations. Hatter

et al.

(2004, p. 9) predicted subpopulation levels within this DPS under three different scenarios: “optimistic,” “most likely,” and “pessimistic.” Under these scenarios population levels were modeled to decline from the estimated population of 1,905 caribou in 2002 to 1,534 (optimistic), 1,169 (most likely), or 820 (pessimistic), by 2022. The most recent population estimate of 1,356 caribou (COSEWIC 2014, p. 41) is already well below Hatter

et al.'

s (2004, p. 9) predicted population estimate of 1,534 caribou in 2022 projected under the optimistic scenario. In addition, all three scenarios reported the extirpation of two (optimistic), three (most likely), or five (pessimistic) subpopulations by 2022 (Hatter

et al.

2004, p. 9). As of 2014, George Mountain and Purcells Central, two of the subpopulations within the southern mountain caribou DPS, are now considered to be extirpated (COSEWIC 2014, p. 16).

According to Hatter

et al.

(2004, pp. 9, 11), no models predicted extinction of the woodland caribou population within the DPS in the next 100 years (Hatter

et al.

2004, p. 11). However, reductions in the size of the entire population were predicted. Using the same scenarios from Hatter

et al.

(2004) as described above (“optimistic,” “most likely,” and “pessimistic”), the average time until the population of woodland caribou within the southern mountain caribou DPS is fewer than 1,000 individuals was projected to be 100, 84, and 26 years, respectively (Hatter

et al.

2004, p. 11). These estimates do not account for the relationship between density and adult female survival, and may be a conservative estimate of time to extinction (in other words, may underestimate the timeframes). Wittmer (2004, p. 88) attempted to account for density-dependent adult female survival and predicted extinction of all subpopulations in the DPS within the next 100 years. More recent population viability analyses (PVAs) have predicted quasi-extinction or extinction of several of the subpopulations within the DPS. A PVA conducted by Hatter (2006, p. 7,

in litt.

) predicted that the probability of quasi-extinction (a number below which extinction is very likely due to genetic or demographic risks, considered to be fewer than 20 animals in this case) in 20 years was 100 percent for 6 of the 15 subpopulations, greater than 50 percent for 11 of the 15 subpopulations, and greater than 20 percent for 12 of the 15 subpopulations within the DPS. Hatter (2006, p. 7,

in litt.

) also predicted quasi-extinction of another subpopulation (Wells Gray) in 87 years. Thus, a total of 13 of the 15 subpopulations could be quasi-extinct within 90 years, leaving only 2 subpopulations (Hart Ranges and North Caribou Mountains) remaining at the extreme northern portion of the DPS's range. Both the Hart Ranges and North Caribou Mountains subpopulations are declining (COSEWIC 2014, p. 41). These two subpopulations are subjected to the same threats acting on the other subpopulations in this DPS (COSEWIC 2014, p. 56), and are thus at a greater risk of extirpation than what we understood at the time of our May 8, 2014, proposed rule (79 FR 26504).

Wittmer

et al.

(2010, entire) conducted a PVA on 10 of the subpopulations assessed by Hatter (2006, entire,

in litt.

). All 10 subpopulations were predicted to decline to extinction within 200 years when models incorporated the declines in adult female survival known to occur with increasing proportions of young forest and declining population densities (Wittmer

et al.

2010, p. 86). The results of PVA modeling by Wittmer

et al.

(2010, p. 90) also suggested that 7 of the 10 populations have a greater than 90 percent cumulative probability of extirpation within 100 years. Further, Wittmer

et al.

(2010, p. 91) suggested that as subpopulation densities decline, predation (see “Predation” under the Factor C analysis, below) may have a disproportionately greater effect, which is defined as depensatory mortality. Thus, the length of time to extirpation may be less than the timeframes suggested by PVA modeling that does not account for depensatory mortality. Therefore, the 200 and 100 year time spans that Wittmer

et al.

(2010, pp. 86, 90) predict for extirpation of all 10 and 7 of the 10 subpopulations, respectively, may be an overestimate (

i.e.,

extirpation of these subpopulations may occur in less time).

Along with these documented and predicted population declines, subpopulations of woodland caribou within the DPS are becoming increasingly fragmented and isolated (Wittmer 2004, p. 28; van Oort

et al.

2011, p. 25; Serrouya

et al.

2012, p. 2,598). Fragmentation and isolation are particularly pronounced in the southern portion of the southern mountain caribou DPS (Wittmer 2004, p. 28). In fact, neither Wittmer

et al.

(2005b, p. 409) nor van Oort

et al.

(2011, p. 221) detected movement of individuals between subpopulations in the DPS.

Fragmentation and isolation are likely accelerating the extinction process and reducing the probability of demographic rescue from natural immigration or emigration because mountain caribou appear to lack the inherent behavior to disperse long distances (Van Oort

et al.

2011, pp. 215, 221-222). As stated previously, mountain caribou were more widely distributed in mountainous areas of southeastern British Columbia (Canada), northern Idaho, and northeastern Washington. Currently, mountain caribou exist in several discrete subpopulations, which could be considered a metapopulation structure. However, a functioning metapopulation structure requires immigration and emigration between the subpopulations within the metapopulation via dispersal of juveniles (natal dispersal), adults (breeding dispersal), or both. Dispersal of individuals (natal or breeding) can facilitate demographic rescue of neighboring populations that are in decline or recolonization of ranges from which populations have been extirpated (

i.e.,

classic metapopulation theory). Species whose historical distribution was more widely and evenly distributed (such as mountain caribou) (van Oort

et al.

2011, p. 221) that have been fragmented into subpopulations via habitat fragmentation and loss may appear to exist in a metapopulation structure when in fact, because they may not have evolved the innate behavior to disperse among subpopulations, their fragmented distribution may actually represent a geographic pattern of extinction (van Oort

et al.

2011, p. 215). Also, as excerpted from COSEWIC (2014, p. 43):

Rescue effect from natural dispersal is unlikely for the southern mountain DU. The nearest subpopulation in the United States is the South Selkirk subpopulation, which is shared between [British Columbia], Idaho, and Washington, and currently consists of only 28 mature individuals. Even within the southern mountain DU, subpopulations are effectively isolated from one another with almost no evidence of movement between them except at the northern extent of the DU (van Oort

et al.

2011). The closest DU is the Central Mountain and Northern Mountain DU, but these animals are not only declining in most neighboring subpopulations but are adapted to living in shallow snow environments and will likely encounter difficulty adjusting to deep snow conditions. The same characteristics that render all three mountain caribou DUs as discrete and significant relative to neighboring caribou subpopulations (see Designatable Units; COSEWIC 2011) make the prospects for rescue highly unlikely.

Finally, COSEWIC recommended that the southern mountain DU be listed as endangered under SARA (COSEWIC 2014, pp. iv, xix). Endangered is defined by SARA as a wildlife species that is facing imminent extirpation or extinction. COSEWIC cited similar reasons as the threats we identified in this final rule including, but not limited to: Small, declining, and isolated subpopulations; recent extirpation of two subpopulations; recent PVA modeling predicting further declines and extirpation of subpopulations; and continuing and escalating threats (COSEWIC 2014, pp. iv, vii). The International Union for the Conservation of Nature-Conservation Measures Partnership (IUCN-CMP) threat assessment for the southern mountain DU concluded that the threat impact is the maximum (Very High) based on the unified threats classification system (Master

et al.

2009, entire), which indicates continued serious declines are anticipated (COSEWIC 2014, pp. 109-113).

Summary of Factors Affecting the Species

Section 4 of the Act (16 U.S.C. 1533), and its implementing regulations at 50 CFR part 424, set forth the procedures for adding species to the Federal Lists of Endangered and Threatened Wildlife and Plants. Under section 4(a)(1) of the Act, we determine whether a species is an endangered species or threatened species because of any one or a combination of the following: (A) The present or threatened destruction, modification, or curtailment of its habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) the inadequacy of existing regulatory mechanisms; and (E)

other natural or manmade factors affecting its continued existence. Listing actions may be warranted because of any of the above threat factors, singly or in combination. We discuss each of these factors for the southern mountain caribou DPS below.

A. The Present or Threatened Destruction, Modification, or Curtailment of Its Habitat or Range

Threats to caribou habitat within the southern mountain DPS include forest harvest, human development, recreation, and effects due to climate change (such as an increase in fires and a significant decrease in alpine habitats, which is loosely correlated with the distribution of the arboreal lichens on which these caribou depend). In addition to causing direct impacts, these threats often catalyze indirect impacts to caribou, including, but not limited to, predation, increased physiological stress, and displacement from important habitats. Both direct and indirect impacts to caribou from habitat destruction, modification, and curtailment are described below.

Historically, the caribou subpopulations that make up the southern mountain caribou DPS were distributed throughout the western Rocky Mountains of British Columbia, northern Idaho, and northeastern Washington (Apps and McLellan 2006, p. 84). As previously discussed, caribou within the southern mountain caribou DPS are strongly associated with high-elevation, high-precipitation, old-growth forested landscapes (Stevenson

et al.

2001, pp. 3-5; Cichowski

et al.

2004, pp. 224, 231; Apps and McLellan 2006, pp. 84, 91; COSEWIC 2011, p. 50) that support their uniquely exclusive winter diet of arboreal lichens (Cichowski

et al.

2004, p. 229).

It is estimated that about 98 percent of the caribou in the southern mountain caribou DPS rely on arboreal lichens as their primary winter food. They have adapted to the high-elevation, deep-snow habitat that occurs within this area of British Columbia, northern Idaho, and northeastern Washington (Apps and McLellan 2006, p. 84). The present distribution of woodland caribou in Canada is much reduced from historical accounts, with reports indicating that the extent of occurrence in British Columbia and Ontario populations has decreased by up to 40 percent in the last few centuries (COSEWIC 2002, pp. viii, 30). According to Spalding (2000, p. 40) the entire range of southern mountain caribou has decreased by 60 percent when including both the United States and Canadian portion of the population's historical range. The greatest reduction has occurred in subpopulations comprising the southern mountain caribou DPS (COSEWIC 2002, p. 30; COSEWIC 2011, p. 49). Hunting was historically considered the main cause of range contraction in the central and southern portions of British Columbia. However, predation, habitat fragmentation from forestry operations, and human development are now considered the main concerns (COSEWIC 2002, p. 30).

Forest Harvest

Forestry has been the dominant land use within the range of the southern mountain caribou DPS in British Columbia throughout the 20th century. The majority of timber harvesting has occurred since the late 1960s (Stevenson

et al.

2001, pp. 9-10). Prior to 1966 and before pulp mills were built in the interior of British Columbia, a variety of forest harvesting systems were utilized, targeting primarily spruce and Douglas fir (

Pseudotsuga menziesii

) sawlogs, and pole-sized western red cedar. It was not until after 1966, when market conditions changed to meet the demand for pulp and other timber products, that the majority of timber harvesting occurred through clear-cutting large blocks of forest (Stevenson

et al.

2001, p. 10). However, in the 1970s, some areas in the southern Selkirk Mountains and the North Thompson area (north of Revelstoke, British Columbia) were only partially cut in an effort to maintain habitat for caribou (Stevenson

et al.

2001, p. 10). In the 1990s, there was an increase in both experimental and operational partial cutting in caribou habitat. Partial cuts continue to remain a small proportion of total area harvested each year within caribou habitat in British Columbia (Stevenson

et al.

2001, p. 10).

Historically, within the U.S. portion of the southern mountain caribou DPS, habitat impacts have been primarily due to logging and fire (Evans 1960, p. 109). In the early 19th century, intensive logging occurred from approximately 1907 through 1922, when the foothills and lowlands were logged upwards in elevation to the present U.S. national forest boundaries (Evans 1960, p. 110). Partly because of this logging, farmlands replaced moister valleys that once resembled the rain forests of the Pacific coast (Evans 1960, p. 111). From the 1920s through 1960, logging continued into caribou habitat on the Kanisku National Forest in Idaho (now the Idaho Panhandle National Forest) (Evans 1960, pp. 118-120). In addition, insect and disease outbreaks affected large areas of white pine (

Pinus strobus

) stands in caribou habitat, and Engelmann spruce habitat was heavily affected by windstorms, insect outbreaks, and subsequent salvage logging (Evans 1960, pp. 123-124). As a result, spruce became the center of importance in the lumber industry of this region. This led to further harvest of spruce habitat in adjacent, higher elevation drainages previously unaffected by insect outbreaks (Evans 1960, pp. 124-131). It is not known how much forest within the range of the southern mountain caribou DPS has been historically harvested; however, forest harvest likely had and continues to have direct and indirect impacts on caribou and their habitat, contributing to the curtailment and modification of the habitat of the southern mountain caribou DPS.

Harvesting of forests has both direct and indirect effects on caribou habitat within the southern mountain caribou DPS. A direct effect of forest harvest is loss of large expanses of contiguous old-growth forest habitats. Caribou in the southern mountain caribou DPS rely upon these habitats as an important means of limiting the effect of predation. Their strategy is to spread over large areas at high elevation that other prey species avoid (Seip and Cichowski 1996, p. 79; MCTAC 2002, pp. 20-21). These old-growth forests have evolved with few and small-scale natural disturbances such as wildfires, insects, or diseases. When these disturbances did occur, they created only small and natural gaps in the forest canopy that allowed trees to regenerate and grow (Seip 1998, pp. 204-205). Forest harvesting through large-scale clear-cutting creates additional and larger openings in old-growth forest habitat. These openings allow for additional growth of early seral habitat.

Research of woodland caribou has shown that caribou alter their movement patterns to avoid areas of disturbance where forest harvest has occurred (Smith

et al.

2000, p. 1435; Courtois

et al.

2007, p. 496). With less contiguous old-growth habitat, caribou are also limited to increasingly fewer places on the landscape. Further, woodland caribou that do remain in harvested areas have been documented to have decreased survival due to predation vulnerability (Courtois

et al.

2007, p. 496). This is because the early seral habitat, which establishes itself in recently harvested or disturbed areas, also attracts other ungulate species such as deer, elk, and moose to areas that were previously unsuitable for these species (MCST 2005, pp. 4-5; Bowman

et al.

2010, p. 464). With the increase in the distribution and abundance of prey species in or near habitats located where

caribou occur comes an increase in predators and therefore an increase in predation on caribou. Predation has been reported as one of the most important direct causes of population decline for caribou in the southern mountain caribou DPS (see also

C. Disease or Predation,

below; MCST 2005, p. 4; Wittmer

et al.

2005a, p. 257; Wittmer

et al.

2005b, p. 417; Wittmer

et al.

2007, p. 576).

Roads created to support forest harvest activities have also fragmented habitat. Roads create linear features that provide easy travel corridors for predators into and through difficult habitats where caribou seek refuge from predators (MCST 2005, p. 5; Wittmer

et al.

2007, p. 576). It has been estimated that forest roads throughout British Columbia (which includes the southern mountain caribou DPS) expanded by 4,100 percent (from 528 to 21,748 mi (850 to 35,000 km)) between 1950 and 1990, and most of these roads were associated with forest harvesting (Stevenson

et al.

2001, p. 10). In the United States, roads associated with logging and forest administration developed continuously from 1900 through 1960. These roads allowed logging in new areas and upper-elevation drainages (Evans 1960, pp. 123-124). In both Canada and the United States, these roads have also generated more human activity and human disturbance in habitat that was previously less accessible to humans (MCST 2005, p. 5). See

E. Other Natural or Manmade Factors Affecting Its Continued Existence

for additional discussion.

The harvest of late-successional (old-growth) forests directly affects availability of arboreal lichens, the primary winter food item for caribou within the southern mountain caribou DPS. Caribou within this area rely on arboreal lichens for winter forage for 3 or more months of the year (Apps

et al.

2001, p. 65; Stevenson

et al.

2001, p. 1; MCST 2005, p. 2). In recent decades, however, local caribou populations in the southern mountain caribou DPS have declined faster than mature forests have been harvested. This suggests that arboreal lichens are not the limiting factor for woodland caribou in this area (MCST 2005, p. 4; Wittmer

et al.

2005a, p. 265; Wittmer

et al.

2007, p. 576).

Forest Fires

Forest fires can have the same effect on mountain caribou habitat in the southern mountain caribou DPS as forest harvesting. Fires cause direct loss of important old-growth habitat and increase openings that allow for the growth of early seral habitat, which is conducive to use by other ungulates, such as deer and moose, but not by mountain caribou, which require old growth, mature forests. Historically, natural fires occurred at very low frequency and extent throughout the range of the southern mountain caribou DPS. This was due to the very wet conditions of the interior wet-belt (Stevenson

et al.

2001, p. 3). When fires did occur, most were relatively small in size (Seip 1998, p. 204). Fires can remove suitable habitat for 25 to 100 years or longer depending on fire intensity, geography, and type of forage normally consumed by caribou (COSEWIC 2002, p. 45). As previously discussed, changes in habitat conditions have led to altered predator-prey dynamics, resulting in more predation on caribou in the southern mountain caribou DPS. One of the first notable declines of caribou was reported in Wells Gray Park, British Columbia (within the southern mountain caribou DPS), and was attributed to fires in the 1930s that burned approximately 70 percent of forests below 4,000 ft (1,219 m) within the park (Edwards 1954, entire). These fires changed forest composition, leading to increased populations of other ungulates, such as mule deer and moose (Edwards 1954, p. 523), which altered the predator-prey dynamics. The 1967 Sundance, Kanisku Mountain, and Trapper Peak fires in the Selkirk Mountains destroyed almost 80,000 ac (32,375 ha) of caribou habitat (Layser 1974, p. 51). In 2006, the Kutetl fire in West Arm Park (British Columbia) destroyed nearly 19,768 ac (8,000 ha) of caribou habitat (Wildeman

et al.

2010, pp. 1, 14, 33, 36, 61). Forest fires are a natural phenomenon and historically occurred at low frequency and extent throughout the range of the southern mountain caribou DPS prior to human settlement. However, fires are predicted to increase in frequency and magnitude due to the effects of climate change (Littell et al. 2009, p. 14) (see “Climate Change,” below), thereby continuing to impact caribou habitat in the southern mountain caribou DPS into the future.

Insect Outbreaks

Engelmann spruce beetles (

Dendroctonus engelmannii

) have been known to kill large amounts of old-growth forest and caribou habitat in western Canada and the northwestern United States. Spruce bark beetle (

Dendroctonus rufipennis

) outbreaks and resulting tree mortality within the southern mountain caribou DPS occurred in the late 1940s, 1950s, 1960s, and 1980s. Some of these outbreaks followed tree wind-throw or forest fires in the United States (Evans 1960, p. 124; USFWS 1985, p. 21).

More recently, mountain pine beetle (

Dendroctonus ponderosae

) outbreaks and mass tree mortality in western Canada have occurred in the 1990s and 2000s. Caribou habitat affected by mountain pine beetle outbreaks may remain viable for caribou, or may even provide better forage for a period of time, perhaps as long as a decade. This is because dead and dying trees may remain standing and continue to provide arboreal lichens to foraging caribou. However, eventually these trees fall and arboreal lichens become scarcer, forcing caribou to seek alternate habitat (Hummel and Ray 2008, p. 252).

Beetle outbreaks have impacted caribou within the southern mountain caribou DPS by directly removing habitat and associated arboreal lichens from the landscape (Evans 1960, p. 132). In addition to eliminating caribou habitat, these beetle outbreaks have brought increased logging operations to high-elevation forests. This logging was done in an attempt to salvage the valuable wood resource in these forest stands. However, this activity also brought human presence and an increase in the potential for poaching and disturbance (Evans 1960, p. 131; USFWS 1985, p. 21). Interestingly, because of the spruce bark beetle outbreaks and a sudden increase in spruce harvest, the logging industry, in an attempt to sell the wood that was being salvaged from the mid-century spruce bark beetle outbreaks, aggressively promoted and developed a market for spruce wood. The associated demand they created for spruce wood continued after the salvaged wood was exhausted, probably leading to continued logging of spruce forests at high elevations. This continued logging of spruce continued the elimination of habitat and prolonged disturbance to caribou beyond the direct impacts from the beetle infestations (Evans 1960, p. 131).

Management of beetle outbreaks for caribou has involved attempting to preserve alternate habitat until affected forests have time to regenerate and once again become suitable for caribou (Hummel and Ray 2008, p. 252). It is not clear to what extent insect infestations will continue into the future; however, climate change models project more frequent mountain pine beetle outbreaks at higher elevations in the future (Littell

et al.

2009, p. 14).

Human Development

Human development fragments habitat within and between local caribou populations in the southern

mountain caribou DPS and creates potential impediments to unrestricted caribou movements (MCST 2005, p. 5). Impediments in valley bottoms, such as human settlements, highways, railways, and reservoirs, have led to an isolation of subpopulations (MCST 2005, p. 5; Wittmer

et al.

2005b, p. 414) and reduced chance of rescue (the movement of individuals, often juveniles, to other subpopulations, which can provide genetic flow and recruitment to populations with very low numbers) from natural immigration or emigration (van Oort

et al.

2011, pp. 220-223; Serrouya

et al.

2012, p. 2,598). Similar to forest harvest and fires, human development and its associated infrastructure also impact caribou in the following ways: It eliminates caribou habitat, alters the distribution and abundance of other ungulate species, provides travel corridors for predators (MCST 2005, p. 5), and increases human access to habitat that was previously difficult to access.

Despite signs posted with caribou depictions warning motorists, caribou have also been killed by vehicles on highways within the range of the southern mountain caribou DPS (Johnson 1985, entire; Wittmer

et al.

2005b, p. 412; CBC News 2009,

in litt.

). The 1963 opening of the Creston-Salmo section of Highway 3 in British Columbia has led to increased vehicle collisions with mountain caribou. Seven caribou were struck and killed on this section of Highway 3 within the first 9 years of its construction (Johnson 1985, entire). More recently, in 2009, a pregnant caribou cow and calf were killed by a vehicle travelling on Highway 3 near Kootenay Pass in British Columbia (CBC News 2009,

in litt.

). Deaths of individual caribou from car collisions can have notable adverse effects on subpopulations. This is because of the small population sizes of the southern-most populations within the southern mountain caribou DPS and the low productivity and calf survival rates as discussed under “Biology” in the

Species Information

section of the May 8, 2014, proposed rule (79 FR 26507).

Highways and their associated vehicle traffic can also fragment caribou habitat and act as impediments to animal movement (Forman and Alexander 1998, p. 215; Dyer

et al.

2002, p. 839; Fahrig and Rytwinski 2009, entire). Species like the southern mountain caribou DPS, which have relatively large ranges, low reproductive rates, and low natural densities, are more likely to be negatively affected by roads (Fahrig and Rytwinski 2009, entire). It has been postulated that the Trans-Canada Highway may also be acting as an impediment to caribou movements in certain areas of the southern mountain caribou DPS (Apps and McLellan 2006, p. 93). Additionally, other type of transportation corridors associated with industrial developments, including roads, snowmobile trails, hydropower transmission lines, and pipeline rights-of-way, can allow more efficient travel by wolves, leading to greater predation rate on caribou (Festa-Bianchet

et al.

2011, p. 426) (see also

C. Disease or Predation,

below).

As discussed above, industrial development can directly affect caribou through habitat alteration that fragments caribou habitat and displaces caribou to areas of lower quality or degraded habitat, and indirectly through increased predation rates resulting from changes in predator-prey dynamics due to habitat alterations. In accordance with SARA, Canada has developed a recovery strategy for southern mountain caribou that assessed threats related to industrial developments (Environment Canada 2014, entire). In the recovery strategy, Canada identified the following threats: Oil and gas drilling related to shale gas development in the Kootenays present a moderate threat (defined as possible in the short term [less than 10 years or 3 generations]); mining and quarrying development primarily in the Barkerville, Kootenay, and Kamloops areas present a high threat (defined as continuing); renewable energy related to hydropower projects in the Columbia South and North ranges, and wind farms, present moderate threats; roads and railroad (

e.g.,

Highway 3, Mica Dam Road, and potential twinning of the Trans-Canada Highway) present a high threat; and utility and service lines related to hydro-power project, potential twinning of the Kinder-Morgan oil pipeline, proposed oil and gas pipelines in the Hart Ranges, etc., present a high threat (Environment Canada 2014, pp. 21-22). All of the above-identified threats are or would be located in Canada. Currently, there are no similar existing or proposed industrial developments that would potentially impact caribou habitat within the DPS's range in the United States.

Mining activities, although they may not be focused in valleys, may also fragment caribou habitat and limit their dispersal and movement. Additionally, these activities may play a role in the alteration of the distribution and abundance of other ungulate species. These activities may also provide travel corridors for predators (MCST 2005, p. 5), as well as increase human accessibility to habitat that was previously difficult to access. The current extent of direct and indirect impacts to caribou from existing mining activities within the southern mountain caribou DPS is not well known.

Human Recreation

Human-related activities are known to impact caribou. Specifically, as described below, wintertime recreational activities such as snowmobiling, heli- or cat-skiing, and back-country skiing are likely to impact short-term behavior, long-term habitat use (MCST 2005, p. 5), and physiology (Freeman 2008, p. 44) of caribou. It is uncertain if these activities are affecting all populations within the southern mountain caribou DPS. Literature suggests that trail compaction resulting from high levels of wintertime recreational activities such as snowmobiling and snowshoeing may act as travel corridors for predators such as wolves. These trails allow easier access into winter caribou habitat that was previously more difficult for predators to navigate (Simpson and Terry 2000, p. 2; Cichowski

et al.

2004, p. 241).

Snowmobile activity represents the greatest threat to caribou within the southern mountain caribou DPS relative to other winter recreation activities due to the overlap between preferred snowmobile habitat and preferred caribou habitat (Simpson and Terry 2000, p. 1). Deep snow, open forest, and scenic vistas are characteristics found in caribou winter habitat, and are also preferred by snowmobilers (Seip

et al.

2007, p. 1,539), and snowmobilers can easily access these areas (Simpson and Terry 2000, p. 1). New forest roads may even be providing increased access to these areas (Seip

et al.

2007, p. 1539).

Within the southern mountain caribou DPS, caribou have been shown to alter their behavior by fleeing from (Simpson 1987, pp. 8-10), and dispersing from, high-quality winter habitat because of snowmobile activity (Seip

et al.

2007, p. 1,543). Altered behavior in response to winter recreation in the form of fleeing can have energetic costs to caribou (Reimers

et al.

2003, pp. 751-753). Perhaps more significantly, however, altered long-term habitat occupancy due to snowmobiling may force caribou within the southern mountain caribou DPS into inferior habitat where there may be energetic costs as well as elevated risks of predation or mortality from avalanches (Seip

et al.

2007, p. 1,543). Anecdotal reports of caribou being notably absent in areas where they had been historically present, but where snowmobile activity had begun or increased (Kinley 2003, p. 20; USFS 2004, p. 12; Seip

et al.

2007, p. 1,539),

support this concept. Further, Freeman (2008, p. 44) showed that caribou exhibit signs of physiological stress within and as far away as 6 mi (10 km) from snowmobile activity. Physiological stress in this study was estimated using fecal glucocorticoids (GC). Glucocorticoids, when chronically elevated, can reduce fitness of an individual by impacting feeding behavior, growth, body condition, resistance to disease, reproduction, and survival (Freeman 2008, p. 33). Caribou within 6 mi (10 km) of open snowmobile areas within the southern mountain caribou DPS showed chronically elevated GC levels. This suggests that snowmobile activity in certain areas of the southern mountain caribou DPS is causing some level of physiological stress to caribou and may be impacting caribou in some way. However, elevated GC levels may be caused by many different environmental factors and may not always translate to impacts (Romero 2004, p. 250; Freeman 2008, p. 48). The extent of impacts from chronically elevated GC levels in caribou appears to need further study (Freeman 2008, p. 46).

Given our understanding of the impacts to caribou from human disturbance (Simpson 1987, pp. 8-10), and information on other ungulate species relative to helicopter disturbance (Cote 1996, p. 683; Webster 1997, p. 7; Frid 2003, p. 393), the presence of humans and machines (helicopters or snow-cats) in caribou habitat from heli- or cat-skiing may be a potential source of disturbance to caribou in certain portions of the southern mountain caribou DPS. This disturbance is likely negatively impacting caribou by altering their behavior and habitat use patterns. Elevated GC levels in caribou has been documented within heli-ski areas. This suggests that heli-skiing activity in certain areas of the southern mountain caribou DPS is causing some level of physiological stress to caribou (Freeman 2008, p. 44). Additionally, since heli- and cat-skiing often require tree cutting for run and/or road maintenance, habitat alteration may be another threat posed from this activity (Hamilton and Pasztor 2009, entire). Further study may be necessary to understand the degree of impact to caribou from heli- and cat-skiing.

Disturbance impacts to caribou from backcountry skiing also are relatively unstudied. Our current knowledge of caribou responses to human disturbance suggests that backcountry skiing may be a potential source of disturbance to caribou, negatively impacting them by altering their behavior. These impacts are likely similar to behavioral alterations from heli- or cat-skiing (Simpson and Terry 2000, p. 3; USFS 2004, p. 24). Duchesne

et al.

(2000, pp. 313-314) found that the presence of humans on snowshoes and skis impacted caribou behavior by altering foraging and vigilance, albeit this study was conducted outside the southern mountain caribou DPS where caribou foraging behavior is different. This study also suggested that caribou may habituate to this level of human disturbance (Duchesne

et al.

2000, p. 314). Given the possibility of habituation, the relatively slow pace of activity participants, and the non-motorized nature of backcountry skiing or snowshoeing, it is suspected that this recreation activity at its current level poses a relatively small threat to caribou within certain areas of the southern mountain caribou DPS (Simpson and Terry 2000, p. 3; USFS 2004, p. 24). However, since the magnitude of impacts may be correlated with the number of activity participants in an area (Simpson and Terry 2000, p. 3), this activity may be a larger threat to caribou within the southern mountain caribou DPS in the future as some areas become more accessible from an expanded network of roads and increasing populations.

Each of these activities—snowmobiling, heli- or cat-skiing, and backcountry skiing—has the potential to disturb caribou. The extent to which caribou are impacted is likely correlated with the intensity of activity (Simpson 1987, p. 9; Duchesne

et al.

2000, p. 315; Reimers

et al.

2003, p. 753). Nature-based recreation and tourism are on the rise in rural British Columbia, with projected growth of approximately 15 percent per year (Mitchell and Hamilton 2007, p. 3). New forest roads may be providing increased access to caribou habitat as well (Seip

et al.

2007, p. 1539). As such, the threat of human disturbance may be a contributing factor in caribou population declines within the southern mountain caribou DPS in the future.

Climate Change

Our analyses under the Act include consideration of the effects of ongoing and projected changes in climate. The terms “climate” and “climate change” are defined by the Intergovernmental Panel on Climate Change (IPCC), an international body established in 1988 to assess the science related to climate change and provide policymakers with regular assessments of the scientific basis of climate change, its impacts and future risks, and options for adaptation and mitigation. “Climate” refers to the mean and variability of different types of weather conditions over time. Thirty years is a typical period for such measurements, although shorter or longer periods also may be used (IPCC 2007, p. 78; IPCC 2014, pp. 119-120). The term “climate change” thus refers to a change in the mean or variability of one or more measures of climate (

e.g.,

temperature or precipitation) that persists for an extended period, typically decades or longer, whether the change is due to natural variability, human activity, or both (IPCC 2007, p. 78; IPCC 2014, p. 120). Various types of changes in climate can have direct or indirect effects on species. These effects may be positive, neutral, or negative (Thomas

et al.

2011, pp. 126, 131, 136-137) and they may change over time. This change depends on the species and other relevant considerations, such as the effects of interactions of climate with other variables (

e.g.,

habitat fragmentation) (IPCC 2007, pp. 8-14, 18-19). In our analyses, we used our expert judgment to weigh relevant information, including uncertainty, in our consideration of various aspects of climate change.

Between the 1600s and the mid-1800s, Europe and North America were in a period called the “Little Ice Age.” During this period, Europe and North America experienced relatively colder temperatures (IPCC 2001, p. 135). The cooling during this time is considered to be modest, with average temperature decreases of less than 1.8 degrees Fahrenheit (°F) (1 degree Celsius (°C)) relative to 20th century levels. Cooling may have been more pronounced in certain regions and during certain periods, such as in North America during the 1800s (IPCC 2001, p. 135).

On a global scale, climate change models under a range of emission scenarios consistently project future increases in temperature and increased precipitation at higher latitudes (Melillo et al. 2014, p. 33). At regional scales there is more variability, particularly when projecting future changes in precipitation. Average temperature has increased in the Northwest 1.3 °F between 1895 and 2011 (Dalton et al. 2013, p. xxi; Melillo et al. 2014, p. 489), while precipitation has fluctuated, but without a significant trend, during the same time period (Dalton et al. 2013, p. xxi; Melillo et al. 2014, p. 489). Temperature and precipitation extremes are projected to increase in the Northwest (Dalton et al. 2013, p. xxiii). For every season, some models project decreases and some project increases in future precipitation, but in a scenario of continued growth in heat-trapping gas emissions, summer precipitation is

projected to decrease by as much as 30 percent by the end of the century (2099) across many climate models. However, the projected changes in precipitation are relatively small compared to projected changes in temperature, and are likely to be masked by natural variability for much of the century (Melillo et al. 2014, p. 489). Increasing temperatures are likely to result in reduced snowpack accumulation in the winter and accelerated loss of snowpack in the spring (Mote et al. 2005, p. 48; Knowles et al. 2006, p. 4558). The earlier snowmelt that would result from projected temperature increases in the Northwest would reduce the amount of available water in the summer (Melillo et al. 2014, p. 11), expand the frost-free season (Melillo et al. 2014, p. 31), and increase the annual maximum number of consecutive dry days (Melillo et al. 2014, p. 33). Virtually all future climate scenarios for the Pacific Northwest project increases in wildfire in western North America, especially east of the Cascades. This projected increase is due to higher summer temperatures, earlier spring snowmelt, and lower summer flows, which can lead to drought stress in trees (Littell

et al.

2009, p. 14). Westerling et al. (2006, pp. 942-943) compiled information on large wildfires in the western United States from 1970 to 2004, and found that large wildfire activity has increased significantly from the mid-1980s with large-wildfire frequency, longer wildfire duration, and longer wildfire seasons. The greatest increases occurred in high-elevation forest types including lodgepole pine and spruce fir in the northern Rockies. They also found that fire exclusion had little impact on natural fire regimes. Rather, climate appeared to be the primary driver of increasing wildfire risk. Lastly, climate change may lead to increased frequency and duration of severe storms and droughts (Golladay

et al.

2004, p. 504; McLaughlin

et al.

2002, p. 6,074; Cook

et al.

2004, p. 1,015).

Review of climate change modeling presented in Utzig (2005, p. 5) demonstrated projected shifts in habitats within the present range of the southern mountain caribou DPS in Canada. Projections for 2055 indicate a significant decrease in alpine habitats, which is loosely correlated with the distribution of the arboreal lichens on which these caribou depend. The projected biogeoclimatic zone distributions indicate a significant increase in the distribution of western red cedar in the mid-term with a shift upward in elevation and northward over the longer term. Projected subalpine fir distribution is similar, with a predicted shift upward in elevation and long-term decreasing presence in the south and on the drier plateau portions of the present range of the southern mountain caribou DPS. More recent analysis by Utzig (2012, pp. 11-15) suggests that while western red cedar will maintain a significant presence throughout the southern portion of the DPS, spruce fir forests and alpine parkland will approach near elimination by the 2080s. Similarly, Rogers

et al.

(2011, pp. 5-6) analysis of three climate projection models indicate that subalpine forests (which contain subalpine fir) may be almost completely lost in the Pacific Northwest (Washington and Oregon) by the end of the 21st century. The loss of subalpine and alpine parkland would be detrimental to the southern mountain caribou DPS given the population's reliance on these habitat types for forage of arboreal lichens during the late winter and for summer habitat (Utzig 2005, p. 2). Thus, habitat in the southern extent of the southern mountain caribou DPS may become unsuitable, thereby restricting the southern range of this southern mountain caribou DPS (Rogers

et al.

2011, pp. 5-6).

The movements of subpopulations within the southern mountain caribou DPS are closely tied to changes in snow depth and consolidation of the snow pack, allowing access to arboreal lichens in winter (Kinley

et al.

2007, entire). Snowpack depth is significant in determining the height at which arboreal lichens occur on trees, and the height at which caribou are able to access lichens in the winter. These arboreal lichens are also dependent upon factors influenced by climate, including humidity and stand density (Utzig 2005, p. 7). Kinley et al. (2007, entire) found that during low snow years, mountain caribou in deep-snowfall regions made more extensive use of low-elevation sites (sometimes associated with the use of stands of lodgepole pine (

Pinus contorta

) and western hemlock) during late winter. When snowpack differences were slight between years in these regions, mountain caribou did not shift downslope as they did during low snow years (Kinley et al. 2007, p. 93). In general, climate change projections suggest reduced snowpacks and shorter winters, particularly at lower elevations (Utzig 2005, p. 7; Littell

et al.

2009, p. 1). Consistently lower snowpacks (similar to what is projected with climate change) at higher elevations may alter the height of lichen growth on trees which may affect seasonal caribou movement patterns. Thus, caribou may remain at higher elevations throughout winter under various climate change scenarios. Additionally, climate change may increase predation pressure on caribou through altered distribution and abundance of other ungulate species populations.

Projections for 2085 indicate an increase in drier vegetation types at lower elevations. This could potentially cause an increase in other ungulate species such as deer, moose, and elk within the range of the southern mountain caribou DPS (Utzig 2005, p. 4). This may result in increased predator numbers in response to increased prey availability, and increased predation on caribou (Utzig 2005, p. 4). For example, in northern Alberta, changes in summer and winter climate are driving range expansion of white-tailed deer, with further changes expected with continuing climate change (Dawe 2011, p. 153). This increase in white-tailed deer is expected to alter predator-prey dynamics, leading to greater predation on woodland caribou by wolves (Latham

et al.

2011, p. 204). This potential increase in predation pressure on the southern mountain caribou DPS is in addition to the risk of increased predation due to forest harvesting and fires that reduces and fragments suitable habitat (Stevenson

et al.

2001, p. 1), as described above.

Virtually all future climate scenarios for the Pacific Northwest project increases in wildfire in western North America, especially east of the Cascades. This is due to higher summer temperatures, earlier spring snowmelt, and lower summer flows, which can lead to drought stress in trees (Littell

et al.

2009, p. 14). In addition, due to climatic stress to trees and an increase in temperatures more favorable to mountain pine beetles (

Dendroctonus ponderosae

), outbreaks of mountain pine beetles are projected to increase in frequency and cause increased tree mortality (Littell

et al.

2009, p. 14). These outbreaks will reach higher elevations due to a shift to favorable temperature conditions as these regions warm (Littell

et al.

2009, p. 14). Other species of insects, such as spruce beetle (

Dendroctonus rufipennis

) and western spruce budworm (

Choristoneura occidentalis

), may also emerge in forests where temperatures are favorable (Littell

et al.

2009, p. 15). These projected impacts to forested ecosystems have the potential to further impact habitat for the southern mountain caribou DPS through alteration of forest patch size and fragmentation that may facilitate increased predation pressure on caribou, and stand structure that may

reduce forage availability (

e.g.,

arboreal lichens) for caribou (Utzig 2005, p. 8).

The information currently available regarding the effects of global climate change and increasing temperatures does not allow precise estimates of the location and magnitude of the effects. However, we do expect changes in climate such as increasing temperatures will result in the following: A shorter snow season with shallower snowpacks, increased forest disturbance, and vegetation growing in far from optimal climatic conditions (Columbia Mountains Institute of Applied Ecology 2006, p. 49). Utzig (2005, entire) provided the most applicable summary of the potential effects of climate change to the southern mountain caribou DPS. In his paper, he noted that there are general indications that the present range of mountain caribou may be reduced in some areas and increased in others (p. 10), as the ecosystem upon which they rely undergoes drastic future changes due to changes in the form and timing of precipitation events (snow versus rain), and vegetative responses to climatic conditions (

e.g.,

drier conditions will mean increased occurrence of fire and disease in mature trees that support arboreal lichens (p. 8)). These climatic conditions may also increase other ungulate species (deer, moose) and lead to higher levels of predator prey interactions (p. 4). He also identified several uncertainties (pp. 10-11), such as the impossibility of reliably projecting specific ecosystem changes and potential impacts. Utzig (p. 11) acknowledged that caribou survived the last glacial period, as well as intervening climate change over the last 10,000 years, although those changes likely occurred over a longer period of time than the changes occurring today.

Given the above information, we anticipate that changes in climate could directly impact the southern mountain caribou DPS by: (1) Reducing the abundance, distribution, and quality of caribou habitat; (2) limiting the ability of caribou to move between seasonal habitats; and (3) limiting their ability to avoid predation. Impacts from climate change may also affect caribou and their habitat by affecting external factors such as increased disease and insect outbreaks, increased fire occurrence, and changes in snow depth. The impacts from these effects could lead to increased habitat fragmentation and changes in forest composition, changes in forage availability and abundance, and changes in predation, which are each important to caribou survival. Because of the close ties between caribou movement and seasonal snow conditions, seasonal shifts in snow conditions will likely significantly impact the southern mountain caribou DPS (Utzig 2005, pp. 4, 8). A trend towards hotter and drier summers, increasing fire events, and unpredictable snow conditions has the potential to reduce both recruitment and survival of the southern mountain caribou DPS of mountain caribou (Festa-Bianchet

et al.

2011, p. 427). A warming climate will negatively affect all aspects of caribou ecology and exacerbate the impact of other threats (Festa-Bianchet

et al.

2011, p. 424).

Conservation Efforts To Reduce Habitat Destruction, Modification, or Curtailment of Its Range

Efforts in the United States:

Efforts to protect the southern mountain caribou DPS and its habitat in the United States include: (1) Retaining mature to old-growth cedar/hemlock and subalpine spruce/fir stands; (2) analyzing forest management actions on a site-specific basis to consider potential impacts to caribou habitat; (3) avoiding road construction through mature old-growth forest stands unless no other reasonable access is available; (4) placing emphasis on road closures and habitat mitigation based on caribou seasonal habitat needs and requirements; (5) controlling wildfires within southern Selkirk Mountains woodland caribou management areas to prevent loss of coniferous tree species in all size classes; and (6) managing winter recreation in the Colville National Forest (CNF) in Washington, with specific attention to snowmobile use within the Newport/Sullivan Lake Ranger District.

Relative to human access within caribou habitat, motorized winter recreation, specifically snowmobiling, represents one threat to caribou within the southern Selkirk Mountains woodland caribou recovery area. U.S. Forest Service 1987 land resource management plans (LRMPs) included some standards calling for motorized use restrictions when needed to protect caribou. The CNF's LRMP in Washington has been revised to incorporate special management objectives and standards to address potential threats to woodland caribou on the forest. The CNF also manages winter recreation in areas of potential conflict between snowmobile use and caribou, specifically in its Newport/Sullivan Lake Ranger District (77 FR 71042, November 28, 2012, see p. 71071). The Idaho Panhandle National Forests (IPNF), beginning in 1993, implemented site-specific closures to protect caribou on IPNF. However, more comprehensive standards addressing how, when, and where to impose such restrictions across IPNF were limited (USFS 1987, entire). In December 2005, a U.S. District Court granted a preliminary injunction prohibiting snowmobile trail grooming within the caribou recovery area on the IPNF during the winter of 2005 to 2006. The injunction was granted because the IPNF had not developed a winter recreation strategy addressing the effects of snowmobiling on caribou. In November 2006, the court granted a modified injunction restricting snowmobiling and snowmobile trail grooming on portions of the IPNF within the recovery area of the southern Selkirk Mountains caribou. On February 14, 2007, the court ordered a modification of the current injunction to add a protected caribou travel corridor, connecting habitat in the U.S. portion of the southern Selkirk Mountains with habitat in British Columbia. This injunction is currently in effect and restricts snowmobiling on 239,588 ac (96,957 ha), involving 71 percent of the existing woodland caribou recovery area. In its revised LRMP (USFS 2015, entire), the IPNF considered the court-ordered snowmobile closure to be the standard until a winter travel plan is approved. The Service will work closely with the IPNF on the future development of their winter recreation strategy, which will be subject to section 7 consultation under the Act.

Within the range of the southern Selkirk Mountains population of woodland caribou is the 43,348-ac (17,542-ha) Salmo-Priest Wilderness area (U.S. Department of Agriculture (USDA) 2013,

in litt.

). The USFS manages these lands under the Wilderness Act of 1964 (16 U.S.C. 1131-1136), which restricts activities in the following manner: (1) New or temporary roads cannot be built; (2) there can be no use of motor vehicles, motorized equipment, or motorboats; (3) there can be no landing of aircraft; (4) there can be no other form of mechanical transport; and (5) no structure or installation may be built.

A recovery plan for the endangered southern Selkirk Mountains population of woodland caribou was finalized in 1994 (1994 recovery plan), outlining interim objectives necessary to support a self-sustaining caribou population in the Selkirk Mountains (USFWS 1994a, entire). Among these objectives was a goal to secure and enhance at least 443,000 ac (179,000 ha) of caribou habitat in the Selkirk Mountains. However, the recovery criteria in this recovery plan were determined to be inadequate in the Service's 5-year review (USFWS 2008, p. 15). Additional

recovery actions are needed as the 2015 population estimate for this subpopulation has dropped to 14 individuals, which continues a steady decline from 46 caribou in 2009 (Degroot 2015,

in litt.

). In addition, the 1994 recovery plan only applies to 1 subpopulation (southern Selkirk Mountain population of woodland caribou) of the 15 extant subpopulations that comprise the southern mountain caribou DPS.

Efforts in Canada:

In 2007, the British Columbia government endorsed the Mountain Caribou Recovery Implementation Plan (MCRIP), which encompasses the southern mountain caribou DPS in Canada (British Columbia Ministry of Agriculture and Lands (BCMAL) 2007,

in litt.

). The plan's goal is to restore the southern mountain caribou DPS in British Columbia to the pre-1995 level of 2,500 individuals (BCMAL 2007,

in litt.

). Actions identified in the MCRIP include, but are not limited to: Protecting approximately 5,436,320 ac (2,200,000 ha) of range from logging and road building, which would capture 95 percent of high-suitability winter habitat; managing human recreation activities; managing predator populations of wolf and cougar where they are preventing recovery of populations; managing the primary prey base of caribou predators; and augmenting threatened herds with animals transplanted from elsewhere (BCMAL 2007,

in litt.

). The Province of British Columbia pledged to provide $1,000,000 per year, over 3 years, to support adaptive management plans associated with the MCRIP (BCMAL 2007,

in litt.

).

As stated above, one of the tools of the 2007 MCRIP for achieving recovery of mountain caribou is augmentation of small subpopulations with caribou translocated from other areas. Pursuant to the 2007 MCRIP, an augmentation plan for the Purcells South Mountain Caribou Population was finalized in 2010, and included a goal of achieving a population target of 100 caribou through augmenting 40 caribou into the Purcell South subpopulation over 2 years (Cichowski

et al.

2014

in litt.,

p. ii). Twenty caribou were captured in March 2012 (first phase) from the Level-Kawdy subpopulation in northwestern British Columbia (located outside of the southern mountain caribou DU/DPS), fitted with radio collars, and 19 of the caribou (1 caribou died prior to release) were augmented into the Purcell South subpopulation located in south-eastern British Columbia, within the southern mountain caribou DU/DPS. As of the 2013 annual report, 17 of the 19 caribou have died (6 due to cougar predation; 2 due to wolf predation; 3 due to accidents; 3 from unknown but confirmed non-predation causes; 2 from unknown causes, predation not ruled out; and 1 from malnutrition due to ticks) (Gordon 2013

in litt.,

p. 1). The satellite collars on the two remaining caribou failed. However, the remaining cow was sighted approximately 112 mi (180 km) north of the Purcells South range, and when the collar on the remaining bull failed, he was utilizing high-elevation habitat with resident caribou and is presumed to still be with the resident group (Cichowski

et al.

2014

in litt.,

p. 2). Implementation of the second phase has not been initiated.

All national parks in Canada are managed by Parks Canada, and are strictly protected areas where commercial resource extraction and sport hunting are not permitted (Parks Canada National Park System Plan (NPSP) 2009, p. 3). Parks Canada's objective for their national parks is, “To protect for all time representative natural areas of Canadian significance in a system of national parks, to encourage public understanding, appreciation, and enjoyment of this natural heritage so as to leave it unimpaired for future generations” (Parks Canada NPSP 2009, p. 2). The southern mountain caribou DPS in British Columbia encompasses two Canadian national parks, Glacier and Mount Revelstoke. Both of these national parks comprise 333,345 ac (134,900 ha) and are within the range of several subpopulations of caribou in the southern mountain caribou DPS (Parks Canada NPSP 2009, pp. 18-19). Ninety-four percent of the land in British Columbia is considered Provincial Crown lands, of which 33,881,167 ac (13,711,222 ha) are designated as various park and protected areas managed by British Columbia (B.C.) Parks (B.C. Parks 2013a,

in litt.

). The mission of B.C. Parks is to “protect representative and special natural places within the province's Protected Areas System for world-class conservation, outdoor recreation, education and scientific study” (B.C. Parks 2013b,

in litt.

). Many Canadian national parks, provincial parks, and ecological reserves, including Arctic Pacific Lakes, Evanoff, Sugarbowl-Grizzly Den, Ptarmigan Creek, West Twin, Close to the Edge, Upper Rausch, Mount Tinsdale, Bowron Lake, Cariboo Mountains, Wells Gray, Upper Adams, Foster Arm, Cummins Lakes, Goosegrass, Glacier, Mount Revelstoke, Monashee, Goat Range, Purcell Wilderness, Kianuko, Lockhart Creek, West Arm, and Stagleapare, are regularly or occasionally occupied by subpopulations or individuals of mountain caribou and these areas provide some level of protection.

In February 2009, British Columbia's Ministry of Environment (BCMOE) protected 5,568,200 ac (2,253,355 ha) of currently available and eventually available high-suitability winter caribou habitat. This was accomplished through the issuance of 10 Government Actions Regulation (GAR) orders on Provincial Crown lands within the southern mountain caribou DPS (BCMOE 2009a,

in litt.;

BCMOE 2009b,

in litt.;

Mountain Caribou Recovery Implementation Plan Progress Board (MCRIPPB) 2010, pp. 7, 9). This protection was accomplished, in part, through the official designation of high-suitability habitats as either wildlife habitat areas or ungulate winter ranges, and associated general wildlife measures (BCMOE 2009b,

in litt.

). These measures were designed to reduce the impact from timber harvest and road construction on caribou habitat. They identified areas where no or modified timber harvesting can take place, along with certain motor vehicle prohibition regulations (BCMOE 2009b,

in litt.;

BCMOE 2009c,

in litt.

). This effort included the creation of two important guidance documents that provide recommendations for the establishment of mineral exploration activity and commercial backcountry recreation (

i.e.,

heli-skiing and cat-skiing). Both of these documents call for their respective activities to maximize use of existing roads and clearings, and specify other activity-specific restrictions on habitat alteration (Hamilton and Pasztor 2009, pp. 7-8; BCMOE 2009c,

in litt.

).

In February 2009, the BCMOE closed approximately 2,471,050 ac (1,000,000 ha) of caribou habitat within the Canadian portion of the southern mountain caribou DPS to snowmobile use (MCRIPPB 2010, p. 10). However, compliance with closures in these areas is not well known, and is likely not 100 percent (MCRIPPB 2012, p. 9). Efforts and progress are being made to replace stolen or vandalized signs, to improve monitoring and enforcement of compliance, and to inform and educate the users about the closed areas. Specifically, several tickets have been issued in British Columbia for noncompliance, and informational pamphlets have been made and distributed (MCRIPPB 2010, p. 10; MCRIPPB 2012, p. 9).

Under SARA, Federal, provincial, and territorial government signatories agreed to establish complementary legislation and programs that provide effective protection of species at risk throughout Canada (Environment Canada 2014, p.

i). SARA requires Federal competent ministers to prepare recovery strategies for species listed under SARA (Environment Canada 2014, p. i). The Minister of the Environment and the Minister responsible for the Parks Canada Agency are the competent ministers under SARA for southern mountain caribou (Environment Canada 2014, p. i). In 2014, in accordance with SARA, the BCMOE published the Recovery Strategy for the Woodland Caribou, Southern Mountain population (

Rangifer tarandus caribou

) in Canada (2014 Canadian Recovery Strategy) that set forth a recovery goal of achieving a self-sustaining population of 2,500 caribou in the southern mountain caribou DU (Environment Canada 2014, p. 29). The 2014 Canadian Recovery Strategy will be followed by development of action plans identifying recovery measures to be taken by the Environment Canada, the Parks Canada Agency, and the Province of British Columbia (Environment Canada 2014, p. i). The 2014 Canadian Recovery Strategy identified several actions that are already completed or are underway including, but not limited to:

• Consideration of southern mountain caribou habitat requirements when planning and implementing forest harvesting and other industrial activities, including prohibition of forest harvesting and road building activities in 2.2 million ha (5.4 million ac) (

e.g.,

Ungulate Winter Ranges, protected areas) to protect high suitability habitat for southern mountain caribou in the Southern Group (also defined as the southern mountain caribou (DU 9)) in British Columbia;

• Consideration of southern mountain caribou habitat when planning and implementing prescribed fires in national parks and on other lands, including conducting prescribed fires in areas away from caribou habitat to maintain a safe distance between caribou and predators;

• Closure to snowmobiling of 1 million ha (2.5 million ac) of high-elevation habitat within ranges of southern mountain caribou in the Southern Group in British Columbia;

• Development and implementation of operating procedures for helicopter and snowcat skiing in southern mountain caribou in the Southern Group in British Columbia;

• Development and implementation of operating guidelines for industrial development within southern mountain caribou ranges;

• Land-use planning to identify areas within southern mountain caribou ranges where southern mountain caribou conservation is prioritized;

• Reduced speed zones on highways in important caribou habitat;

• Predator and alternate prey management projects in some ranges where subpopulations of southern mountain caribou are declining; and

• Population augmentation through translocations and reduction of early calf mortality through maternal penning.

In addition, implementation of voluntary stewardship management agreements in British Columbia may contribute to conservation of the southern mountain caribou DPS. These agreements are between the BCMOE and snowmobiling groups, and promote the minimization of disturbance and displacement of caribou from snowmobile activities in their habitat. Through these agreements, snowmobile groups agree to abide by a code of conduct while riding in designated areas, volunteer to educate riders about impacts to caribou and preventative measures to avoid impacts, volunteer to monitor designated areas for compliance, and submit reports to the BCMOE detailing caribou sightings and snowmobile use of an area. To date, 13 of these agreements have been signed between the BCMOE and snowmobile organizations (MCRIPPB 2010, p. 10). Finally, a maternal penning trial is being implemented near Revelstoke, British Columbia, Canada, and a memorandum of understanding has been signed between Parks Canada and the Calgary Zoo to develop captive breeding capacity for mountain caribou (MCRIPPB 2014, p. 5).

Private Efforts:

Approximately 135,908 ac (55,000 ha) of private land within the British Columbia portion of the southern Selkirk Mountains caribou recovery area were purchased by the Nature Conservancy Canada (NCC). This purchase was made with the support of the Government of Canada in what has been described as the largest single private conservation land acquisition in Canadian history (USFWS 2008, p. 17). This private land was previously owned by a timber company known as the Pluto Darkwoods Forestry Corporation, which managed a sustainable harvesting program prior to selling the land. The NCC's goal for the Darkwoods property is sustainable ecosystem management, including the conservation of woodland caribou (USFWS 2008, p. 17).

Summary for Factor A

Destruction, modification, or curtailment of caribou habitat has been and is today a significant threat to caribou throughout the southern mountain caribou DPS. Specific threats directly impacting caribou habitat within the southern mountain caribou DPS include forest harvest, forest fires, insect outbreaks, human development, recreation, and effects of climate change. Each of these threats, through varying mechanisms, directly removes and fragments existing habitat and/or impacts caribou behavior such that it alters the distribution of caribou within their natural habitat.

Forest harvest, forest fires, insect outbreaks, human development, and effects due to climate change may catalyze other indirect threats to caribou within the southern mountain caribou DPS. These impacts may be particularly prevalent in the southern extent of this DPS. Specifically, direct habitat loss and fragmentation further limits caribou dispersal and movements among subpopulations within the southern mountain caribou DPS by making it more difficult and more dangerous for caribou to disperse. Additionally, habitat loss and fragmentation have and will continue to alter the predator-prey ecology of the southern mountain caribou DPS by creating more suitable habitat and travel corridors for other ungulates and their predators. Finally, habitat loss and fragmentation increases the likelihood of disturbance of caribou in the southern mountain caribou DPS from human recreation or other activities by increasing the accessibility of these areas to humans. Projections of changes in climate indicate that the changes will exacerbate impacts by catalyzing forest composition changes; increasing forest insect outbreaks; and increasing the likelihood of wildfires through changes in phenology, precipitation (both timing and quantity), and temperature.

Another threat, human disturbance from wintertime recreation, particularly from snowmobile activity, increases physiological stress and energy expenditure, and alters habitat occupancy of caribou. This disturbance forces caribou to use inferior habitat with greater risk of depredation or avalanche. Human disturbance is likely to continue to increasingly impact caribou within the southern mountain caribou DPS because nature-based recreation and tourism are on the rise in rural British Columbia. Projected growth of these activities is estimated at approximately 15 percent per year (Mitchell and Hamilton 2007, p. 3). In addition, the establishment of new forest roads may be providing increased human access to caribou habitat, further amplifying the threat of human disturbance and caribou population declines within the southern mountain caribou DPS in the future. Impacts to caribou from human disturbance are

occurring today, despite conservation measures, and are likely to occur in the future. These impacts will likely contribute to the decline of subpopulations within the southern mountain caribou DPS and further impact the continued existence of the southern mountain caribou DPS.

We have evaluated the best available scientific and commercial data on the present or threatened destruction, modification, or curtailment of the habitat or range of the southern mountain caribou DPS. Through this evaluation, we have determined that the activities identified under this factor pose significant threats to the continued existence of the southern mountain caribou DPS, especially when considered in concert with the other factors impacting the southern mountain caribou DPS.

B. Overutilization for Commercial, Recreational, Scientific, or Educational Purposes

Caribou have been an important game species since they have shared the landscape with humans. Native Americans have hunted caribou for thousands of years in British Columbia, although the numbers of animals taken were probably modest given the relatively limited hunting pressure and hunting implements at the time (Spalding 2000, p. 38). The introduction of firearms combined with a later increase in human populations in British Columbia led to an increase in caribou harvested by the late 1800s and into the 1900s (Spalding 2000, p. 38).

It is thought that an increase in hunting pressure, although it did not cause extinction, upset the already delicate balance between predators and caribou and catalyzed a general decline in caribou populations (Seip and Cichowski 1996, p. 73; Spalding 2000, p. 39). In support of this hypothesis, Spalding (2000, p. 39) cited old field reports that hunters, both Native American and non-Native American, were killing too many caribou. He also cited several regions of British Columbia where, after hunting closures were implemented, caribou numbers began to rebound, although this was not the case in all populations (Spalding 2000, p. 37). These hunting pressures and associated population declines subsided with the hunting season closures, and some regions of British Columbia even saw population increases and stabilization after the 1940s (Spalding 2000, pp. 37, 39).

Hunting of caribou is currently not allowed in any of the lower 48 United States. While hunting of mountain caribou is allowed within certain areas of British Columbia (British Columbia Hunting and Trapping Regulations/Synopsis 2014-2016), according to Chris Ritchie (2015, pers. comm.), there is no legal harvest of mountain caribou allowed within the range of the southern mountain caribou DU/DPS in Canada. Further, hunting is prohibited in all national parks and ecological reserves in British Columbia, but may be allowed in some specific British Columbia parks. Consequently, legal harvest has not been a major limiting factor to caribou within the southern mountain caribou DPS since the mid-1970s (Seip and Cichowski 1996, p. 73). Therefore, although it may have had a historical impact on caribou populations, hunting/harvesting of caribou is not presently impacting caribou within the southern mountain caribou DPS.

Although there are historical reports of the illegal harvest of caribou within the southern mountain caribou DPS (Scott and Servheen 1985, p. 15; Seip and Cichowski 1996, p. 76), we do not have data that suggest illegal killing is affecting caribou numbers in any of the subpopulations within the southern mountain caribou DPS.

Conservation Efforts To Reduce Overutilization for Commercial, Recreational, Scientific, or Educational Purposes

Aside from State and Provincial regulations that limit hunting of caribou, we are unaware of other conservation efforts to reduce overutilization for commercial, recreational, scientific, or educational purposes; however, we do not have information suggesting that overutilization is an ongoing threat to caribou within the southern mountain caribou DPS.

Summary for Factor B

Threats from overutilization such as hunting appear to be ameliorated, now and in the future, by responsible management. Historically, caribou within the southern mountain caribou DPS were hunted throughout their range. They were likely overharvested when human populations increased in British Columbia and with the advent of modern weapons. The hunting of caribou has been made illegal within the southern mountain caribou DPS, in both the United States and Canada. After hunting ceased, certain populations began to recover but others did not. Even though there have been known occurrences of humans illegally killing caribou within the southern mountain caribou DPS in the past, we do not have information indicating this is an ongoing threat. We have evaluated the best available scientific and commercial data on the overutilization for commercial, recreational, scientific, or educational purposes of the southern mountain caribou DPS and determined that activities identified under this factor do not pose threats to the continued existence of the southern mountain caribou DPS.

C. Disease or Predation

Disease

Caribou mortality due to disease and parasitism has been documented throughout their range and within the southern mountain caribou DPS (Spalding 2000, p. 40; Compton

et al.

1995, p. 493; Dauphine 1975

in

COSEWIC 2002, pp. 20, 54-55). The effects of many types of biting and stinging insects on caribou include parasite and disease transmission, harassment, and immune system reactions (COSEWIC 2002, p. 54). Several insects with the potential to affect caribou populations include warble flies (

Oedemagena

spp.), nose bot flies (

Cephenemyia trompe

), mosquitoes (

Aedes

spp.), black flies (

Simulium

spp.), horseflies (

Tabanus

spp.), and deer flies (

Chrysops

spp.) (COSEWIC 2002, p. 54). Mature and old woodland caribou are likely to have a relatively high incidence and prevalence of hydatid cysts (

Echinococcus granulosus

) in their lungs, which can make them more susceptible to predation (COSEWIC 2002, p. 54). Eggs and larvae of the protostrongylid nematode (

Parelaphostrongylus andersoni

) can develop in woodland caribou lungs and can contribute to pneumonia (COSEWIC 2002, pp. 54-55). Finally, a related meningeal nematode (

P. tenuis

) causes neurologic disease in caribou. Although this nematode is benign in white-tailed deer, it may be a limiting factor to caribou in southern Ontario and west to Saskatchewan. Samuel

et al.

(1992, p. 629) suggested that this meningeal nematode may anthropogenically spread in western Canada due to game ranching; however, we have no new information to determine if this spread has or has not occurred.

Within the southern mountain caribou DPS, evidence of disease or parasitism is limited. We know that several caribou that were shot or found dead in a forest near Rooney, British Columbia, in 1918 were thought to have a type of pneumonia (Spalding 2000, p. 40). We also know that, of 34 caribou that died within 2 years of translocation to the southern Selkirk Mountains, only one was confirmed to have died of

severe parasitism (

Sarcocystis

sp.) and emaciation (Compton

et al.

1995, p. 493). Additionally, in 2012, 19 caribou were translocated from the Level-Kawdy subpopulation in northwestern British Columbia into the Purcell Mountains subpopulation in southeastern British Columbia, Canada. Of the 19 translocated caribou, one died from malnutrition due to ticks (Gordon 2013,

in litt.

). Although evidence within the southern mountain DPS is limited, we are aware that a reintroduction effort of 51 caribou outside of the southern mountain caribou DPS in the late 1960s failed, presumably because of meningeal worms (

Parelaphostrongylus tenuis

) (Dauphine 1975

in

COSEWIC 2002, p. 20).

As is the case with most wildlife, caribou are susceptible to disease and parasitism. These sources of mortality are likely causing some level of impact to individual caribou within the southern mountain caribou DPS. However, because no severe outbreaks have been documented and because relatively few caribou within the southern mountain caribou DPS have been known to succumb to disease or parasitism, these sources of mortality are unlikely to have significantly impacted caribou within the southern mountain caribou DPS, currently or historically.

Predation

Natural predators of caribou in the southern mountain caribou DPS include cougars (

Felis concolor

), wolves (

Canis lupus

), grizzly bears (

Ursus arctos

), and black bears (

Ursus americanus

) (Seip 2008, p. 1). Increased predation from these natural predators, particularly wolves and cougars, is thought to be the most, or one of the most, significant contributors to southern mountain caribou DPS declines in recent decades (Seip 1992, p. 1,500; Kinley and Apps 2001, p. 161; MCST 2005, p. 4, Wittmer

et al.

2005b, pp. 414-415). McLellan

et al.

(2012, entire) investigated whether interactions with forage (bottom-up) or predators (top-down) were the principal mechanisms regulating southern mountain caribou populations. They concluded that apparent competition (

i.e.,

predation) is the proximate mechanism driving the population decline of mountain caribou (McLellan

et al.

2012, p. 859). Apparent competition occurs indirectly between prey populations that share a common food-limited predator, whereby the predator asymmetrically impacts the prey populations (Holt 1977, pp. 201-202), even without resource competition between the prey species. For example, in this case, the numerical response of predators (

e.g.,

wolves and cougars) to the primary prey (

i.e.,

deer, elk, moose) can depress the population of the secondary prey (

i.e.,

caribou), resembling competition between the prey species. Predation on the secondary prey can be incidental, can increase proportionately as the numbers of secondary prey decline (Sinclair

et al.

1998 in Wittmer

et al.

2005a, p. 259), and can lead to extinction of the secondary prey (DeCesare

et al.

2010, pp. 353, 355). McLellan

et al.

(2012, p. 859) also concluded that food limitation (neither quality nor quantity) is likely not driving the continued population decline of mountain caribou.

As cited previously the decline of this population is accelerating (COSEWIC 2014, p. vii). Wittmer

et al.

(2005b, p. 264) found that predation was the primary cause of mortality driving the accelerated rate of population decline of mountain caribou. The accelerated rate of decline of the overall population composed of small, fragmented, and isolated subpopulations is consistent with the Allee effect

2

(Stephens

et al.

1999, p. 186), which predicts population growth rates to decline as populations become smaller. Increased predation pressure on small populations is one example of an Allee effect, but genetic drift can also result in an Allee effect (Stephens

et al.

1999, p. 185).

2

The Allee effect is a phenomenon in biology characterized by a correlation between population size or density and the mean individual fitness (often measured as per capita population growth rate) of a population or species.

Genetic drift can result from rapid changes in gene frequencies caused by environmental and demographic stochasticity independent of mutation and natural selection, and smaller populations are more susceptible to genetic drift. For example, when alleles

3

occur at a low frequency in a small population, these alleles have a significant probability of being lost in each generation. The gradual loss of rare alleles from a population changes the overall genotype of the population, and ultimately results in a loss of genetic variability. Serrouya

et al.

(2012, p. 2,597) demonstrated that below a population size of approximately 150 caribou, the magnitude and variation of genetic differentiation greatly increased between pairs of adjacent subpopulations (

i.e.,

genetic drift). In summary, genetic drift reduces genetic variation in populations, potentially reducing a population's ability to evolve in response to new selective pressure, and genetic drift acts faster and has more drastic results in small populations.

3

One member of a pair of genes occupying a specific spot on a chromosome that controls the same trait.

Elevated levels of predation on caribou in the southern mountain caribou DPS have likely been caused, in part, by an alteration of the natural predator-prey ecology within their range (Wittmer

et al.

2005b, p. 417; Seip 2008, p. 3). This change in the predator-prey ecology within the southern mountain caribou DPS is thought to be catalyzed, at least in part, by human-caused habitat alteration and fragmentation (Seip 2008, p. 3). Habitat alteration and fragmentation within the southern mountain caribou DPS is caused by many things, including, but not limited to, forest harvest, fire, human development, and effects due to climate change (see Factor A discussion, above). Alteration and fragmentation from these and other activities disturb land and create edge habitats. These new edges and disturbances allow for the introduction of early seral habitat that is preferred by deer, elk, and moose, thereby increasing habitat suitability for these alternate ungulate prey species within the southern mountain caribou DPS (Kinley and Apps 2001, p. 162; Seip 2008, p. 3). The increase in habitat suitability for deer, elk, and moose have allowed these alternate prey species to subsist in areas that, under natural disturbance regimes, would have been dominated by contiguous old-growth forest and of limited value to them (Kinley and Apps 2001, p. 162). The result is an altered distribution and increased numbers of these alternative ungulate prey species, particularly within summer habitat of caribou within the southern mountain caribou DPS (Kinley and Apps 2001, p. 162; Wittmer

et al.

2005a, pp. 263-264). Many studies suggest that increases in alternative ungulate prey within caribou summer habitat have stimulated an associated increase of natural predators, particularly cougars and wolves, in these same areas, consequently disrupting the predator-prey ecology within the southern mountain caribou DPS and resulting in increased predation on caribou (Kinley and Apps 2001, p. 162; Wittmer

et al.

2005b, pp. 414-415). Additionally, many studies conducted across the range of mountain caribou (Northern, Central, and Southern DUs) as well as the Boreal DU in Canada suggest these populations of caribou are at risk of extirpation where habitat altering industrial activities affect predator-prey dynamics (Festa-Bianchet

et al.

2011, p. 427).

Habitat alteration and fragmentation has resulted in increased numbers and distribution of other ungulate prey species (

i.e.,

deer, moose, and elk) that

has supported, and continues to support, higher densities of predators which then prey opportunistically on caribou (

i.e.,

apparent competition). It will likely require greater than 150 years (greater than 16 generations of caribou) of habitat protections for early successional and fragmented forests to develop the old-growth habitat characteristics (vegetative structure and composition) (Stevenson

et al.

2001, p. 1) necessary to restore the natural predator-prey balance of these high-elevation, old-growth forests, and thus reduce predation pressure on caribou. As discussed above under Status of the Southern Mountain Caribou DPS, Hatter (2006, p. 7,

in litt.

) predicted quasi-extinction of 13 of the 15 subpopulations within the DPS within 20 to 90 years, and Wittmer

et al.

(2010, p. 86) predicted extinction of 10 of the 15 subpopulations within 200 years (notably, they did not assess 5 of the subpopulations). Thus, the subpopulations within the DPS are not likely sustainable given ongoing declines and the length of time needed to improve habitat conditions that may ameliorate the threat of predation.

The specific changes to predator/prey ecology are different across the southern mountain caribou DPS. In the northern portion of the DPS, wolf and moose populations have increased. In the southern portion of the DPS, cougar, elk, and deer populations have increased. Because alternate ungulate prey are driving predator abundance in caribou habitat (Wittmer

et al.

2005b, p. 414), predators may remain abundant in caribou habitat while caribou numbers remain few. This renders one of the caribou's main predator defenses—predator avoidance—relatively ineffective during certain parts of the year.

Alterations in the predator-prey ecology of the southern mountain caribou DPS may also have been catalyzed, in part, by successful game animal management in the southern mountain caribou DPS (Wittmer

et al.

2005b, p. 415). This too could have helped to increase deer, elk, and moose populations within the southern mountain caribou DPS and led to an increase in ungulate predators, thus impacting caribou.

Conservation Efforts To Reduce Disease or Predation

Disease:

We are not aware of any conservation measures currently being implemented to reduce impacts to caribou from disease.

Predation:

Increased predation is thought to be the current primary threat affecting caribou within the southern mountain caribou DPS (Seip 1992, p. 1,500; Kinley and Apps 2001, p. 161; MCST 2005, p. 4, Wittmer

et al.

2005b, pp. 414-415). Strategies on managing predation may include the management of predator populations directly, or the management of alternate ungulate prey populations. The 2007 Mountain Caribou Recovery Implementation Plan (MCRIP), produced by the BCMOE, proposed that both approaches be taken within the Canadian portion of the southern mountain caribou DPS (MCRIPPB 2010, pp. 1, 12, 13).

Direct management of predator populations within the southern mountain caribou DPS to date has included investigations of the degree of overlap between wolves and caribou home ranges. This research will assist BCMOE with decisions about location and intensity of wolf management or removal (MCRIPPB 2010, p. 12). Currently, BCMOE has authorized removal of wolves from within the southern mountain caribou DPS through hunting and trapping. To date, this program has been implemented only on a limited basis. Initial results suggest this management effort has been successful at reducing wolf densities, but the response by mountain caribou will take several more years to determine (MCRIPPB 2010, p. 12). Finally, a wolf sterilization project is underway in a portion of the southern mountain caribou DPS. This project is a pilot project designed to determine the feasibility and effectiveness of wolf sterilization (MCRIPPB 2010, p. 12). Initial results of this work suggest that some subpopulations are showing a positive response to these sterilization efforts. However, this conclusion is based on a correlation between the two variables and cause-effect has not been demonstrated (Ritchie

et al.

2012, p. 4). One ongoing study in the Purcells South subpopulation is investigating wolf and cougar overlap with caribou home ranges (MCRIPPB 2012, p. 12).

Direct management of alternate ungulate prey populations within the southern mountain caribou DPS, to date, has been limited. The BCMOE has reported two pilot moose-reduction programs within the southern mountain caribou DPS to determine effectiveness of reducing wolf densities through the management of moose densities in caribou habitat (MCRIPPB 2010, p. 13). These pilot efforts have indicated that reducing moose densities may reduce wolf numbers (MCRIPPB 2011, p. 4).

The BCMOE established a Mountain Caribou Recovery Implementation Progress Board (Board) with the publication of the 2007 MCRIP. The Board was charged with oversight of the implementation of the MCRIP and monitoring its effectiveness. The Board's 2010 annual report declared that the conservation measures listed above have all been relatively limited in scope and have failed to meet the expectations of the Board (MCRIPPB 2010, p. 4). The Board's annual reports since 2010 have been slightly more favorable in their assessment of the BCMOE's efforts for predator and alternate ungulate prey management. However, it is still apparent that much research and progress still needs to be completed. For example, it is noteworthy that most of the conservation measures listed above target the wolf-moose predator-prey relationship that is the primary driver of predator-prey dynamics in the northern portion of the southern mountain caribou DPS. We were able to find only one record or report of conservation measures that had been implemented to address predation of caribou by cougars, which may be the most salient issue for the small and struggling subpopulations in the southern portion of the southern mountain caribou DPS (Wittmer

et al.

2005b, pp. 414-415). Given the controversial nature of predator and alternate ungulate prey control for caribou conservation (MCRIPPB 2010, p. 4; MCRIPPB 2012, p. 11), these conservation measures have been and may continue to be slow to develop and difficult to implement.

Efforts at reducing predation in the United States are more limited and not specifically targeted at reducing effects to caribou. In Idaho, caribou are found within game management unit (GMU) 1, which provides recreational hunting opportunities for black bear, mountain lion, and wolves, and also provides a limited trapping season for wolves (Idaho Department of Fish and Game (IDFG) 2012, entire). Within this GMU, between July 1, 2010, and June 30, 2011, 109 mountain lions (IDFG 2011a, p. 6) and 179 black bears (IDFG 2011b, p. 4) were harvested. More recently, from September 1, 2011, through March 31, 2012, 28 wolves were harvested (IDFG 2013,

in litt.

). Washington State provides a limited hunting season for both black bear and mountain lion within GMU 113 (the GMU found in Washington State, Washington Department of Fish and Wildlife (WDFW) 2012, pp. 60-63), and within the critical habitat designated for the southern Selkirk Mountains population of woodland caribou (77 FR 71042, November 28, 2012). Forty-four black bears and 1 mountain lion were harvested in GMU 113 in 2011 (WDFW 2013a,

in litt.;

WDFW 2013b,

in litt.

).

However, wolf hunting or trapping is not allowed in Washington State. As mentioned above, the objectives for these predator hunting and trapping seasons are not to benefit the southern mountain caribou DPS in the United States, and any response in the caribou population is not monitored. As such, any potential effects on caribou survival and population stability from hunting seasons on predators in Idaho and Washington remain unknown.

Summary for Factor C

Predation, particularly from wolves and cougars, is thought to be the most, or one of the most, significant contributors to caribou population declines within the southern mountain caribou DPS in recent decades. Increased predation of caribou within this DPS has likely been caused, in part, by an alteration of the natural predator-prey ecology of the area. This new predator-prey dynamic has been catalyzed by increases in populations of alternative ungulate prey species such as elk, deer, and moose within caribou habitat. Ecosystems that favor these alternate ungulate prey species also favor predators such as wolves and cougars. These changes have likely been catalyzed, in part, by human-caused habitat loss and fragmentation, which increases habitat favorable to alternative ungulate prey species, and consequently attracts increased numbers of predators. Although some conservation measures have been implemented to reduce impacts to subpopulations of caribou from predation, more efficient, intensive, and frequent action is still needed within the southern mountain caribou DPS. We have evaluated the best available scientific and commercial data on disease or predation of the southern mountain caribou DPS and have determined that predation poses a widespread and serious threat to the continued existence of the southern mountain caribou DPS.

D. The Inadequacy of Existing Regulatory Mechanisms

Under this factor, we examine whether existing regulatory mechanisms are inadequate to ameliorate the threats to the species discussed under the other factors. Section 4(b)(1)(A) of the Act requires that the Service take into account “those efforts, if any, being made by any State or foreign nation, or any political subdivision of a State or foreign nation, to protect such species. . . .” In relation to Factor D under the Act, we interpret this language to require the Service to consider relevant Federal, State, and Tribal laws, regulations, and other such mechanisms that may minimize any of the threats we describe in threat analyses under the other four factors or otherwise enhance conservation of the species. We give strongest weight to statutes and their implementing regulations and to management direction that stems from those laws and regulations. An example would be State governmental actions enforced under a State statute or constitution, or Federal action under statute.

Many different regulatory mechanisms and government conservation actions have been implemented in both the United States and British Columbia in an attempt to alleviate threats to caribou within the southern mountain caribou DPS. Below, we list these existing regulatory mechanisms and consider whether they are inadequate to address the identified threats to the southern mountain caribou DPS.

Federal

U.S. Forest Service:

Much of the caribou habitat within the United States is managed by the USFS (289,000 ac (116,954 ha)), although a significant amount of State and private lands (approximately 79,000 ac (31,970 ha)) occur within caribou range as well (USFWS 1994a, p. 21). Land and resource management plans (LRMPs) for the IPNF and the CNF have been revised to incorporate management objectives and standards for caribou. Standards for caribou habitat management have been incorporated into the IPNF's 2015 and CNF's 1988 LRMP, respectively. These standards are meant to avoid the likelihood of jeopardizing the continued existence of the species, contribute to caribou conservation, and ensure consideration of the biological needs of the species during forest management planning and implementation actions (USFS 2015, pp. 29-33; USFS 1988, pp. 4-10-17, 4-38, 4-42, 4-73-76, Appendix I).

We acknowledge that LRMPs can be amended or revised. However, LRMPS are typically in place for 15 years or longer, and the Service, other Federal and State agencies, and the public would have opportunities to comment on any proposed amendments or revisions to the IPNF and/or CNF LRMPs through the National Environmental Policy Act (NEPA; 42 U.S.C. 4321

et seq.

) process. Therefore, we expect that both the IPNF and CNF will continue managing for caribou and their habitat into the future.

The CNF's LRMP in Washington has been revised to incorporate special management objectives and standards to address potential threats to woodland caribou on the CNF. The CNF also manages winter recreation in areas of potential conflict between snowmobile use and caribou, specifically in its Newport/Sullivan Lake Ranger District (77 FR 71042, November 28, 2012, see p. 71071). The IPNF, beginning in 1993, implemented site-specific closures to protect caribou on the IPNF. However, more comprehensive standards addressing how, when, and where to impose such restrictions across the IPNF were limited (USFS 1987, entire). In December 2005, a U.S. district court granted a preliminary injunction prohibiting snowmobile trail grooming within the caribou recovery area on the IPNF during the winter of 2005 to 2006. The injunction was granted because the IPNF had not developed a winter recreation strategy addressing the effects of snowmobiling on caribou. In November 2006, the court granted a modified injunction restricting snowmobiling and snowmobile trail grooming on portions of the IPNF within the southern Selkirk Mountains caribou recovery area. On February 14, 2007, the court ordered a modification of the current injunction to add a protected caribou travel corridor connecting habitat in the U.S. portion of the southern Selkirk Mountains with habitat in British Columbia. This injunction is currently in effect and restricts snowmobiling on 239,588 ac (96,957 ha), involving 71 percent of the existing woodland caribou recovery area. In its revised LRMP (USFS 2013, entire), the IPNF considered the court-ordered snowmobile closure to be the standard until a winter travel plan is approved. The Service will work closely with the IPNF on the future development of their winter recreation strategy. To date, the IPNF has not completed a wint

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