endangered and threatened wildlife and plants; threatened status for the distinct population segment...

7/29/2019 Endangered and Threatened Wildlife and Plants; Threatened Status for the Distinct Population Segment of the Nor

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Vol. 78 Monday,

No. 23 February 4, 2013

Part II

Department of the Interior

Fish and Wildlife Service

50 CFR Part 17Endangered and Threatened Wildlife and Plants; Threatened Status for the

Distinct Population Segment of the North American Wolverine Occurring inthe Contiguous United States; Establishment of a Nonessential

Experimental Population of the North American Wolverine in Colorado,Wyoming, and New Mexico; Proposed Rules

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7864 Federal Register / Vol. 78, No. 23/ Monday, February 4, 2013/ Proposed Rules

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[FWSR6ES20120107: 4500030113]

RIN 1018AY26

Endangered and Threatened Wildlifeand Plants; Threatened Status for theDistinct Population Segment of theNorth American Wolverine Occurringin the Contiguous United States

AGENCY: Fish and Wildlife Service,Interior.

ACTION: Proposed rule.

SUMMARY: We, the U.S. Fish andWildlife Service, propose to list thedistinct population segment of theNorth American wolverine occurring inthe contiguous United States, as athreatened species under the

Endangered Species Act. If we finalizethis rule as proposed, it would extendthe Acts protections to this species. Theeffect of this regulation is to add thedistinct population segment of theNorth American wolverine occurring inthe contiguous United States to the Listof Endangered and Threatened Wildlifein our regulations. We also propose aspecial rule under section 4(d) of theAct to apply the specific prohibitions ofthe Act necessary to protect thewolverine. We find that critical habitatis not determinable at this time. TheService seeks data and comments from

the public on this proposed listing rule,the proposed special rule under section4(d) of the Act, and our finding that thedesignation of critical habitat for thespecies is not determinable at this time.

DATES: We will accept commentsreceived or postmarked on or beforeMay 6, 2013. Comments submittedelectronically using the FederaleRulemaking Portal (see ADDRESSESsection, below) must be received by11:59 p.m. Eastern Time on the closingdate. We must receive requests forpublic hearings, in writing, at theaddress shown in the ADDRESSES section

by March 21, 2013.Public Informational Sessions andPublic Hearing:We will hold 3 publicinformational sessions and publichearings on this proposed rule. Publicinformational sessions will occur from2:00 p.m. to 5:00 p.m. and publichearings will be held from 7:00 p.m. to9:00 p.m. at each location. Publicinformational sessions and publichearings will occur in Boise, ID, onMarch 13, 2013, from 7:00 p.m. to 9:00p.m.; in Lakewood, CO, on March 19,2013, from 7:00 p.m. to 9:00 p.m.; and

in Helena, MT, on March 27, 2013, from7:00 p.m. to 9:00 p.m., all times local(see ADDRESSES). Registration for thoseproviding testimony in the publichearings will begin at 6:00 p.m. at eachlocation.

ADDRESSES: You may submit commentsby one of the following methods:

(1) Electronically:Go to the FederaleRulemaking Portal: http://www.regulations.gov.In the Keyword

box, enter Docket No. FWSR6ES20120107, which is the docket numberfor this rulemaking. Then, in the Searchpanel on the left side of the screen,under the Document Type heading,click on the Proposed Rules link tolocate this document. You may submita comment by clicking on CommentNow!

(2) By hard copy:Submit by U.S. mailor hand-delivery to: Public CommentsProcessing, Attn: FWSR6ES20120107; Division of Policy and Directives

Management; U.S. Fish and WildlifeService; 4401 N. Fairfax Drive, MS2042PDM; Arlington, VA 22203.

(3) At a public hearing:We areholding three public hearings on thisproposed rule (see ADDRESSES forlocation information). You may provideyour comments at any of the threehearings.

We request that you send commentsonly by the methods described above.We will post all comments on http://www.regulations.gov.This generallymeans that we will post any personalinformation you provide us (see the

Public Comments section below formore information).Public Informational Sessions and

Public Hearings:Public informationalsessions and public hearings will beheld on March 13, 2013, at the BoiseCentre on the Grove, 850 West FrontStreet, Boise, ID 83702. The second isscheduled on March 19, 2013, at theHampton Inn, 137 Union Boulevard,Lakewood, CO 80228. The third isscheduled on March 27, 2013, at theRed Lion Colonial Inn, 2301 ColonialDrive, Helena, MT 59601. At all threelocations the public informational

session will run from 2:00 p.m. to 5:00p.m., followed by public speakerregistration at 6:00 p.m., and then thepublic hearing for oral testimony from7:00 p.m. to 9:00 p.m. People needingreasonable accommodations in order toattend and participate in the publichearing should contact Brent Esmoil,Montana Ecological Services FieldOffice, as soon as possible (see FORFURTHER INFORMATION CONTACT).

Any additional tools or supportinginformation that we may develop forthis rulemaking will be available at

http://www.fws.gov/mountain-prairie/species/mammals/wolverine/,at http://www.regulations.govat Docket No.FWSR6ES20120107, and at theMontana Field Office (see FOR FURTHERINFORMATION CONTACT).

FOR FURTHER INFORMATION CONTACT:Brent Esmoil, Field Supervisor (Acting),U.S. Fish and Wildlife Service, MontanaField Office, 585 Shepard Way, Helena,Montana 59601, by telephone (406)4495225. Persons who use atelecommunications device for the deaf(TDD) may call the Federal InformationRelay Service (FIRS) at 8008778339.

SUPPLEMENTARY INFORMATION:

Executive Summary

Why we need to publish a rule. Underthe Endangered Species Act of 1973, asamended (16 U.S.C. 1531 et seq.) (Act orESA), if a species is determined to be anendangered or threatened speciesthroughout all or a significant portion of

its range, we are required to promptlypublish a proposal in the FederalRegister and make a determination onour proposal within 1 year. Criticalhabitat shall be designated, to themaximum extent prudent anddeterminable, for any speciesdetermined to be an endangered orthreatened species under the Act.Listing a species as an endangered orthreatened species and designations andrevisions of critical habitat can only becompleted by issuing a rule.

This rule consists of: A proposed rule to list the distinct

population segment (DPS) of the NorthAmerican wolverine occurring in thecontiguous United States as a threatenedspecies; and

A proposed special rule undersection 4(d) of the Act that outlines theprohibitions necessary and advisable forthe conservation of the wolverine.

A proposed rule under section 10(j) ofthe Act to establish an experimentalnon-essential population of wolverinein Colorado is published concurrentlyin this issue of the Federal Register.Also, a draft Recovery Outline for thewolverine DPS is available on our Web

site at http://www.fws.gov/mountain-prairie/species/mammals/wolverine/oron http://www.regulations.gov.

The basis for our action. Under theAct, we can determine that a species isan endangered or threatened species

based on any of five factors: (A) Thepresent or threatened destruction,modification, or curtailment of itshabitat or range; (B) Overutilization forcommercial, recreational, scientific, oreducational purposes; (C) Disease orpredation; (D) The inadequacy ofexisting regulatory mechanisms; or (E)

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7865Federal Register / Vol. 78, No. 23/ Monday, February 4, 2013/ Proposed Rules

Other natural or manmade factorsaffecting its continued existence.

We have determined that habitat lossdue to increasing temperatures andreduced late spring snowpack due toclimate change is likely to have asignificant negative population-levelimpact on wolverine populations in thecontiguous United States. In the future,

wolverine habitat is likely to be reducedto the point that the wolverine in thecontiguous United States is in danger ofextinction.

We will seek peer review. We areseeking comments from knowledgeableindividuals with scientific expertise toreview our analysis of the best availablescience and application of that scienceand to provide any additional scientificinformation to improve this proposedrule. Because we will consider allcomments and information receivedduring the comment period, our finaldeterminations may differ from this

proposal.Information Requested

We intend that any final actionresulting from this proposed rule will be

based on the best scientific andcommercial data available and be asaccurate and as effective as possible.Therefore, we request comments orinformation from the public, otherconcerned governmental agencies,Native American tribes, the scientificcommunity, industry, or any otherinterested parties concerning thisproposed rule. We particularly seekcomments concerning:

(1) Biological, commercial trade, orother relevant data concerning anythreats (or lack thereof) to this speciesand regulations that may be addressingthose threats.

(2) Additional information concerningthe historical and current status, range,distribution, and population size of thisspecies, including the locations of anyadditional populations of this species.

(3) Any information on the biologicalor ecological requirements of thespecies, and ongoing conservationmeasures for the species and its habitat.

(4) Current or planned activities in the

areas occupied by the species andpossible impacts of these activities onthis species.

(5) The reasons why we should orshould not designate habitat as criticalhabitat under section 4 of the Act (16U.S.C. 1531 et seq.) including whetherand how the wolverine may benefitfrom such a designation; whether thereare threats to the species from humanactivity, the degree to which it can beexpected to increase due to a criticalhabitat designation, and whether thatincrease in threat outweighs the benefit

of designation such that the designationof critical habitat may not be prudent;

(6) Specific information on theamount and distribution of wolverinehabitat,

(7) Information on the projected andreasonably likely impacts of climatechange on the wolverine and its habitat;

(8) Suitability of the proposed 4(d)

rule for the conservation, recovery, andmanagement of the DPS of the NorthAmerican wolverine occurring in thecontiguous United States.

(9) Additional information concerningwhether it is appropriate to prohibitincidental take of wolverine in thecourse of legal trapping activitiesdirected at other species in the proposed4(d) rule, including any informationabout State management plans related totrapping regulations and any measureswithin those plans that may avoid orminimize the risk of wolverine mortalityfrom incidental trapping for otherspecies.

(10) Additional provisions the Servicemay wish to consider to conserve,recover, and manage the DPS of theNorth American wolverine occurring inthe contiguous United States.

We will consider all comments andinformation received during thecomment period on this proposedlisting rule and special rule undersection 4(d) of the Act during ourpreparation of a final determination.Accordingly, the final decision maydiffer from this proposal.

Please note that submissions merelystating support for or opposition to the

action under consideration withoutproviding supporting information,although noted, will not be consideredin making a determination, as section4(b)(1)(A) of the Act directs thatdeterminations as to whether anyspecies is an endangered or threatenedspecies must be made solely on the

basis of the best scientific andcommercial data available.

You may submit your comments andmaterials concerning this proposed rule

by one of the methods listed in theADDRESSES section. We request that yousend comments only by the methods

described in theADDRESSES

section.If you submit information via http://www.regulations.gov,your entiresubmissionincluding any personalidentifying informationwill be postedon the Web site. If your submission ismade via a hardcopy that includespersonal identifying information, youmay request at the top of your documentthat we withhold this information frompublic review. However, we cannotguarantee that we will be able to do so.We will post all hardcopy submissionson http://www.regulations.gov.Please

include sufficient information with yourcomments to allow us to verify anyscientific or commercial informationyou include.

Comments and materials we receive,as well as supporting documentation weused in preparing this proposed rule,will be available for public inspectionon http://www.regulations.gov,or by

appointment, during normal businesshours, at the U.S. Fish and WildlifeService, Montana Field Office (see FORFURTHER INFORMATION CONTACT).

Previous Federal Actions

On April 19, 1995, we published afinding (60 FR 19567) that a previouspetition, dated August 3, 1994,submitted by the Predator Project (nownamed the Predator ConservationAlliance) and Biodiversity LegalFoundation to list the wolverine in thecontiguous United States as anendangered or threatened species, did

not provide substantial informationindicating that listing the wolverine inthe contiguous United States may bewarranted.

On July 14, 2000, we received apetition dated July 11, 2000, submitted

by the Biodiversity Legal Foundation,Predator Conservation Alliance,Defenders of Wildlife, NorthwestEcosystem Alliance, Friends of theClearwater, and Superior WildernessAction Network, to list the wolverinewithin the contiguous United States asan endangered or threatened speciesand designate critical habitat for the

species.On October 21, 2003, we published a90-day finding that the petition failed topresent substantial scientific andcommercial information indicating thatlisting may be warranted (68 FR 60112).

On September 29, 2006, as a result ofa complaint filed June 8, 2005 byDefenders of Wildlife and othersalleging we used the wrong standards toassess the July 11, 2000, wolverinepetition, the U.S. District Court,Montana District, ruled that our 90-daypetition finding (68 FR 60112) was inerror and ordered us to submit to theFederal Register a 12-month finding forthe wolverine by September 29, 2007.On April 6, 2007, the deadline for this12-month finding was extended toFebruary 28, 2008.

On March 11, 2008, we published a12-month finding of not warranted forthe wolverine in the contiguous UnitedStates (73 FR 12929). In that finding wedetermined that the wolverine in thecontiguous United States did notconstitute a distinct population segmentor a significant portion of the range ofa listable entity of the wolverine in

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North America and so was not a listableentity under the Act.

On July 8, 2008 we received a Noticeof Intent to Sue from Earthjusticealleging violations of the Act in ourMarch 11, 2008, 12-month finding. OnSeptember 30, 2008, Earthjustice filed acomplaint in the U.S. District Court,District of Montana, seeking to set aside

and remand the 12-month finding backto the Service for reconsideration.

On March 6, 2009, the Service agreedto settle the case with Earthjustice byvoluntarily remanding the 12-monthfinding and issuing a new 12-monthfinding by December 1, 2010. Followingthe settlement agreement, the courtdismissed the case on June 15, 2009,and ordered the Service to comply withthe settlement agreement.

On April 15, 2010, the Servicepublished a Notice of Initiation of a 12-month finding for wolverines in thecontiguous United States (75 FR 19591).

That finding was published onDecember 14, 2010, and determined thatthe wolverine in the contiguous UnitedStates constituted a Distinct PopulationSegment and that the DPS warrantedlisting under the Act, but that listingwas precluded by higher priority listingactions (75 FR 78030).

On September 9, 2011, we reached anagreement with plaintiffs in EndangeredSpecies Act Section 4 Deadline Litig.,Misc. Action No. 10377 (EGS), MDLDocket No. 2165 (D. DC) (known as theMDL case) on a schedule to publishproposed rules or to withdraw

warranted findings for the species onour list of candidate species. Thisagreement stipulated that we wouldsubmit for publication in the FederalRegister a proposed listing rule for thewolverine, or withdraw the warranted12-month finding, no later than the endof the 2013 Fiscal Year.

On April 13, 2012, several partiesfiled an action challenging the ServicesDecember 14, 2010 warranted butprecluded finding for wolverine.Cottonwood Envtl. Law Ctr., et al. v.Salazar, et al., 9:12-cv-00057DLC (D.Mont.) On September 20, 2012, thecourt granted the Services motion to

stay that litigation based on theServices representation to the Courtthat it expected to submit this rule orwithdraw the warranted finding to theFederal Registerby January 18, 2013.

Threatened Status for the ContiguousUnited States Wolverine DPS

Background

It is our intent to discuss below onlythose topics directly relevant to thelisting of the contiguous United StatesDPS of the North American wolverine as

a threatened species in this section ofthe proposed rule.

Species Information

Taxonomy and Life History

The wolverine has a Holarctic(habitats found in the northerncontinents) distribution includingnorthern portions of Europe, Asia, andNorth America. The currently acceptedtaxonomy classifies wolverinesworldwide as a single species, Gulogulo, with two subspecies. Old Worldwolverines are found in the Nordiccountries of Europe, Russia, and Siberiaand are part of the subspecies Gulo gulogulo. New World wolverines occur inNorth America. The wolverines in thecontiguous United States are a part ofthe New World subspecies, G. g. luscus:the North American wolverine (Kurtenand Rausch 1959 p. 19; Pasitschniak-Arts and Lariviere 1995, p. 1). Thespecies is known by several common

names, including mountain devil,glutton, caracajou, quickhatch, gulon,skunk bear, as well as wolverine.

The wolverine is the largest terrestrialmember of the family Mustelidae. Adultmales weigh 12 to 18 kilograms (kg) (26to 40 pounds (lb)), and adult femalesweigh 8 to 12 kg (17 to 26 lb) (Banci1994, p. 99). The wolverine resembles asmall bear with a bushy tail. It has a

broad, rounded head; short, roundedears; and small eyes. Each foot has fivetoes with curved, semi-retractile clawsused for digging and climbing (Banci1994, p. 99).

A large number of female wolverines(40 percent) are capable of giving birthat 2 years old, become pregnant mostyears, and produce average litter sizes of1 to 2 kits. In one study of known-agedfemales, none reproduced at age 2; 3 of10 first reproduced at age 3; and 2 didnot reproduce until age 4. The averageage at first reproduction was 3.4 years(Persson et al. 2006, pp. 7677).Another study indicated that theaverage age at first reproduction is likelymore than 3 years (Inman et al. 2007c,p. 70). Pregnant females commonlyresorb or spontaneously abort littersprior to giving birth (Magoun 1985, pp.3031; Copeland 1996, p. 43; Persson etal. 2006, p. 77; Inman et al. 2007c, p.70). This may in turn preserve resourcesto increase reproductive success insubsequent years (Persson 2005, p.1456). By age 3, nearly all femalewolverines become pregnant every year,

but energetic constraints due to lowfood availability result in loss ofpregnancy in about half of them eachyear. It is likely that, in many places inthe range of wolverines, it takes 2 yearsof foraging for a female to store enough

energy to successfully reproduce(Persson 2005, p. 1456). It is likely that,despite the high rate of initiation ofpregnancy, due to the spontaneousabortion of litters resulting fromresource limitation, actual rates ofsuccessful reproduction in wolverinesare among the lowest known formammals (Persson 2005, p. 1456).

Supplemental feeding of femalesincreases reproductive potential(Persson 2005, p. 1456). Food-supplemented females were also moresuccessful at raising kits to the time ofweaning, suggesting that wolverinereproduction and ultimately populationgrowth rates and viability are food-limited. Female wolverines appear touse a complex strategy of foodaccumulation and caching to attainenough resources to successfully raise alitter (Inman et al. 2012b, pp. 640641).

Breeding generally occurs from latespring to early fall (Magoun andValkenburg 1983, p. 175; Mead et al.1991, pp. 808811). Females undergodelayed implantation until thefollowing winter or spring, when activegestation lasts from 30 to 40 days(Rausch and Pearson 1972, pp. 254257). Litters are born from mid-Februarythrough March, containing one to fivekits, with an average in North Americaof between one and two kits (Magoun1985, pp. 2831; Copeland 1996, p. 36;Krebs and Lewis 1999, p. 698; Copelandand Yates 2006, pp. 3236; Inman et al.2007c, p. 68).

Female wolverines use natal (birthing)dens that are excavated in snow.

Persistent, stable snow greater than 1.5meters (m) (5 feet (ft)) deep appears to

be a requirement for natal denning,because it provides security foroffspring and buffers cold wintertemperatures (Pulliainen 1968, p. 342;Copeland 1996, pp. 9297; Magoun andCopeland 1998, pp. 13171318; Banci1994, pp. 109110; Inman et al. 2007c,pp. 7172; Copeland et al. 2010, pp.240242). Female wolverines go to greatlengths to find secure den sites,suggesting that predation is a concern(Banci 1994, p. 107). Natal dens consistof tunnels that contain well-used

runways and bed sites and maynaturally incorporate shrubs, rocks, anddowned logs as part of their structure(Magoun and Copeland 1998, pp. 13151316; Inman et al. 2007c, pp. 7172). InIdaho, natal den sites occur above 2,500m (8,200 ft) on rocky sites, such asnorth-facing boulder talus or subalpinecirques (steep-walled semicircular basincarved by a glacier) in forest openings(Magoun and Copeland 1994, pp. 13151316). In Montana, natal dens occurabove 2,400 m (7,874 ft) and are locatedon north aspects in avalanche debris,



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typically in alpine habitats neartimberline (Inman et al. 2007c, pp. 7172). Offspring are born from mid-February through March and the densare typically used through late April orearly May (Myrberget 1968, p. 115;Magoun and Copeland 1998, pp. 13141317; Inman et al. 2007b, pp. 5559).Occupation of natal dens is variable,

ranging from approximately 9 to 65 days(Magoun and Copeland 1998, pp. 13161317).

Females may move kits to multiplesecondary (maternal) dens as they growduring the month of May (Pulliainen1968, p. 343; Myrberget 1968, p. 115),although use of maternal dens may beminimal (Inman et al. 2007c, p. 69).Timing of den abandonment is relatedto accumulation of water in dens (dueto snow melt), the maturation ofoffspring, disturbance, and geographiclocation (Myrberget 1968, p. 115;Magoun 1985, p. 73). After using natal

and maternal dens, wolverines may alsouse rendezvous sites through early July.These sites are characterized by natural(unexcavated) cavities formed by large

boulders, downed logs (avalanchedebris), and snow (Inman et al. 2007c,pp. 5556). Male wolverines likely matewith several females, and although theyare not known to directly contribute torearing young, they do tolerate subadultwolverines in their territories (usuallytheir own offspring) until they reachmaturity (Copeland 1996, p. 72).

Habitat, Space, and Food

In North America, wolverines occur

within a wide variety of alpine, boreal,and arctic habitats, including borealforests, tundra, and western mountainsthroughout Alaska and Canada. Thesouthern portion of the species rangeextends into the contiguous UnitedStates, including high-elevation alpineportions of Washington, Idaho,Montana, Wyoming, California, andColorado (Wilson 1982, p. 644; Hash1987, p. 576; Banci 1994, p. 102,Pasitschniak-Arts and Lariviere 1995, p.499; Aubry et al. 2007, p. 2152; Moriartyet al. 2009, entire; Inman et al. 2009, pp.2225). Wolverines do not appear to

specialize on specific vegetation orgeological habitat aspects, but insteadselect areas that are cold and receiveenough winter precipitation to reliablymaintain deep persistent snow late intothe warm season (Copeland et al. 2010,entire). The requirement of cold, snowyconditions means that, in the southernportion of the species range whereambient temperatures are warmest,wolverine distribution is restricted tohigh elevations, while at more northerlylatitudes, wolverines are present atlower elevations and even at sea level in

the far north (Copeland et al. 2010,Figure 1).

In the contiguous United States,wolverines likely exist as ametapopulation (Aubry et al. 2007, p.2147, Figures 1, 3). A population is agroup of interbreeding individuals ofthe same species. A metapopulation isa population composed of a network of

semi-isolated subpopulations, eachoccupying a suitable patch of habitat ina landscape of otherwise unsuitablehabitat (Pulliam and Dunning 1997, pp.212214). Metapopulations requiresome level of regular or intermittentmigration and gene flow amongsubpopulations, in which individualsubpopulations support one-another byproviding genetic and demographicenrichment through mutual exchange ofindividuals (Meffe and Carroll 1997, p.678). Individual subpopulations may goextinct or lose genetic viability, but arethen rescued by immigration from

other subpopulations, thus ensuring thepersistence of the metapopulation as awhole. If metapopulation dynamics

break down, either due to changeswithin subpopulations or loss ofconnectivity, then the entiremetapopulation may be jeopardized dueto subpopulations becoming unable topersist in the face of inbreeding ordemographic and environmentalstochasticity (Pulliam and Dunning1997, pp. 221222). The wolverinemetapopulation in the DPS consists of anetwork of small subpopulations onmountain tops, some consisting of lessthan ten individuals. Persistence of

subpopulations under these conditionsrequires movement betweensubpopulations across both suitable andunsuitable wolverine habitat.Wolverines prefer to move acrosssuitable habitat (as defined by persistentspring snow cover) rather than to crossunsuitable habitats during dispersalmovements (Schwartz et al. 2009, p.3230). Therefore, we would expect thatchanges resulting in reduction ofsuitable habitat conditions would resultin reduced movement rates betweenhabitat patches if distances betweenthem became greater. This could affect

the metapopulation as a whole ifmovement rates became too low toensure subpopulation demographic orgenetic health.

Wolverines are opportunistic feedersand consume a variety of foodsdepending on availability. Theyprimarily scavenge carrion, but alsoprey on small animals and birds, and eatfruits, berries, and insects (Hornockerand Hash 1981, p. 1290; Hash 1987, p.579; Banci 1994, pp. 111113).Wolverines have an excellent sense ofsmell that enables them to find food

beneath deep snow (Hornocker andHash 1981, p. 1297).

Wolverines require a lot of space; theavailability and distribution of food islikely the primary factor in determiningfemale wolverine movements and homerange size (Hornocker and Hash 1981, p.1298; Banci 1994, pp. 117118). Malewolverine home range size and location

is likely tied to the presence of activefemale home ranges and breedingopportunities (Copeland 1996, p. 74).Female wolverines forage close to densites in early summer, progressivelyranging further from dens as kits

become more independent (May et al.2010, p. 941). Wolverines travel longdistances over rough terrain and deepsnow, and adult males generally covergreater distances than females(Hornocker and Hash 1981, p. 1298;Banci 1994, pp. 117118; Moriarty et al.2009, entire; Inman et al. 2009, pp. 2228; Brian 2010, p. 3; Copeland and Yates

2006, Figure 9). Home ranges ofwolverines are large, and vary greatly insize depending on availability anddistribution of food and gender and ageof the animal. Home ranges of adultwolverines also vary in size dependingon geographic location. Home ranges inAlaska were approximately 100 squarekilometers (km2) to over 900 km2 (38.5square miles (mi2) to 348 mi2) (Banci1994, p. 117). Average home ranges ofresident adult females in central Idahowere 384 km2 (148 mi2), and averagehome ranges of resident adult maleswere 1,522 km2 (588 mi2) (Copeland1996, p. 50). Wolverines in Glacier

National Park had average adult malehome ranges of 496 km2 (193 mi2) andadult female home ranges of 141 km2(55 mi2) (Copeland and Yates 2006, p.25). Wolverines in the GreaterYellowstone Ecosystem had averageadult male home ranges of 797 km2 (311mi2), and average adult female homeranges of 329 km2 (128 mi2) (Inman etal. 2007a, p. 4). These home range sizesare large relative to the body size ofwolverines, and may indicate thatwolverines occupy a relativelyunproductive niche in which they mustforage over large areas to consume the

amount of calories needed to meet theirlife-history requirements (Inman et al.2007a, p. 11).

Across their worldwide distribution,wolverines are dependent on persistentspring snow cover for successfulreproduction (Pulliainen 1968, pp. 338341; Myrberget 1968, p. 115; Copeland1996, pp. 9394; Magoun and Copeland1998, pp. 13151319; Aubry et al. 2007,p. 2153; Inman et al. 2012a, p.785;Copeland et al. 2010, entire). No recordsexist of wolverines denning anywhere

but in snow, despite the wide



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availability of snow-free denningopportunities within the speciesgeographic range. The snow tunnels andcomplex structure associated with densare likely required to protect young frominterspecific and intraspecific predation(Persson et al. 2003, pp. 2526; Magounand Copeland 1998, p. 1318). A layer ofdeep snow may also add crucial

insulation from cold temperatures andwind prevalent in wolverine habitat(Pulliainen 1968, p. 342; Bjarvall et al.1978, p. 2425; Copeland 1996, p. 100;Magoun and Copeland 1998, p. 1318).

Female wolverines have beenobserved to abandon reproductive denswhen temperatures warm and snowconditions become wet (Magoun andCopeland 1998, p. 1316); this responseindicates that the condition of the snowis also important to successfulreproduction, and that the onset ofspring snowmelt forces femalewolverines to move kits into alternate

denning sites with better snowconditions, if they are available. Thesemovements may be energetically costlyand subject females and kits topredation risk. The deep, persistentspring snow layer in the Copeland et al.(2010) model captures all knownwolverine den sites in the DPS;however, on average, most denningoccurs at higher elevations within thearea defined by the model. Femalewolverines establish reproductive densat elevations higher than averageelevations used by nonreproductivewolverines (Copeland 1996, p. 94;Magoun and Copeland 1998, pp. 1315

1316; Inman et al. 2007c, p. 71),suggesting that females find theconditions necessary for successfuldenning in the upper portion of theirhome range where snow is mostpersistent and occurs in the heaviestaccumulations.

Wolverine year-round habitat use alsotakes place almost entirely within thearea defined by deep persistent springsnow (Copeland et al. 2010, pp. 242243). Within the DPS, this area isgenerally centered on the alpine treeline (the maximum elevation beyondwhich tree growth is precluded and

only low-growing vegetation is found).In the contiguous United States,wolverine year-round habitat is found athigh elevations centered near the treeline in conifer forests (below tree line)and rocky alpine habitat (above tree-line) and in cirque basins and avalanchechutes that have food sources such asmarmots, voles, and carrion (Hornockerand Hash 1981, p. 1296; Copeland 1996,p. 124; Magoun and Copeland 1998, p.1318; Copeland et al. 2007, p. 2211;Inman et al. 2007a, p. 11). In thesouthern portion of wolverine range in

North America which includes the DPS,wolverines are constrained by theirneed for cold conditions and persistentspring snow to using only the coldestavailable landscapes (Copeland et al.2010, Figure 6).

Mean seasonal elevations used bywolverines in the northern RockyMountains and North Cascades vary

between 1,400 and 2,600 m (4,592 and8,528 ft) depending on location, but arealways relatively high on mountainslopes (Hornocker and Hash 1981, p.1291; Copeland et al. 2007, p. 2207,Aubry et al. 2007, p. 2153; Inman et al.2012, p. 782). Elevation ranges used byhistorical wolverine populations in theSierra Nevada and southern RockyMountains are unknown, butpresumably wolverines used higherelevations, on average, than morenortherly populations to compensate forthe higher temperatures found at lowerlatitudes. In the contiguous United

States, valley bottom habitat appears tobe used only for dispersal movementsand not for foraging or reproduction(Inman et al. 2009, pp. 2228).Wolverine reproductive dens have beenlocated in alpine, subalpine, taiga, ortundra habitat (Myrberget 1968, p. 115;Pulliainen 1968, pp. 338341; Bjarvall1982, p. 318; Lee and Niptanatiak 1996,p. 349; Landa et al. 1998, pp. 451452;Magoun and Copeland 1998, pp. 13171318). Wolverines rarely, or never, denin lower elevation forested habitats,although they may occupy thesehabitats occasionally (Magoun andCopeland 1998, p. 1317).

Wolverine Densities

Wolverines naturally occur in lowdensities with a reported range from oneanimal per 65 km2 (25 mi2), to oneanimal per 337 km2 (130 mi2)(Hornocker and Hash 1981, pp. 12921295; Hash 1987, p. 578; Copeland1996, pp. 3132; Copeland and Yates2006, p. 27; Inman et al. 2007a, p. 10;Squires et al. 2007, p. 2218). Nosystematic population census existsover the entire current range ofwolverines in the contiguous UnitedStates, so the current population level

and trends are not known withcertainty. However, based on ourcurrent knowledge of occupiedwolverine habitat and wolverinedensities in this habitat, it is reasonableto estimate that the wolverinepopulation in the contiguous UnitedStates numbers approximately 250 to300 individuals (Inman 2010b, pers.comm.). The bulk of the currentpopulation occurs in the northern RockyMountains, with a few individuals inthe North Cascades and one knownindividual each in the Sierra Nevada

and southern Rocky Mountains. Withinthe area known to currently havewolverine populations, relatively fewwolverines can coexist due to theirnaturally low population densities, evenif all areas were occupied at or nearcarrying capacity. Given the naturallimitations on wolverine populationdensity, it is likely that historical

wolverine population numbers werealso low (Inman et al. 2007a, Table 6).Because of these natural limitations, itis possible that densities and populationlevels in the northern Rocky Mountainsand North Cascades where populationscurrently exist may not be substantiallylower than population densities were inthese areas prior to Europeansettlement. However, historically, thecontiguous United States populationwould likely have been larger than it istoday due to the larger area occupied bypopulations when the southern RockyMountains, Bighorn Mountains, Sierra

Nevada, and possibly also the OregonCascades and mountains of Utah, wereoccupied at full capacity.

Wolverine Status in Canada and Alaska

The bulk of the range of NorthAmerican wolverines is found inCanada and Alaska, where wolverinesinhabit alpine tundra, boreal forest, andarctic habitats (Slough 2007, p. 78).Wolverines in Canada have beendivided into two populations formanagement by the CanadianGovernment: An eastern population inLabrador and Quebec, and a westernpopulation that extends from Ontario to

the Pacific coast, and north to the ArcticOcean. The eastern population iscurrently listed as endangered under theSpecies At Risk Act in Canada, and thewestern population is designated as aspecies of special concern (COSEWIC2003, p. 8).

The current status of wolverines ineastern Canada is uncertain. Wolverineshave not been confirmed to occur inQuebec since 1978 (Fortin et al. 2005, p.4). Historical evidence of wolverinepresence in eastern Canada is alsosuspect because no evidence exists toshow that wolverine pelts attributed to

Quebec or Labrador actually came fromthat region; animals were possiblytrapped elsewhere and the pelts shippedthrough the eastern provinces(COSEWIC 2003, p. 20). Wolverines ineastern Canada may currently exist inan extremely low-density population, ormay be extirpated. Wolverines ineastern Canada, both historically andcurrently, could represent migrants fromwestern populations that never becameresident animals (COSEWIC 2003, pp.2021). The Federal Government ofCanada has completed a recovery plan



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for the eastern population with the goalof establishing a self-sustainingpopulation through reintroduction andprotection (Fortin et al. 2005, p. 16).

Wolverines in western Canada andAlaska inhabit a variety of habitats fromsea level to high elevations (Slough2007, pp. 7778). They occur in Alaska,Ontario, Manitoba, Saskatchewan,

Alberta, British Columbia, Yukon,Northwest Territories, and Nunavut(Slough 2007, pp. 7778). SinceEuropean colonization, a generallyrecognized range contraction has takenplace in boreal Ontario and the aspenparklands of Manitoba, Saskatchewan,and Alberta (COSEWIC 2003, pp. 2021;Slough 2007, p. 77). This rangecontraction occurred concurrently witha reduction in wolverine records for theGreat Lakes region in the contiguousUnited States (Aubry et al. 2007, pp.21552156). Causes of these changes areuncertain, but may be related to

increased harvest, habitat modification,or climate change (COSEWIC 2003, pp.2021; Aubry et al. 2007, pp. 21552156; Slough 2007, pp. 7778). Analysissupports climate change as a factorcontributing to population declines insouthern Ontario, because snowconditions necessary to supportwolverines do not currently exist in theGreat Lakes region of the contiguousUnited States, and are marginal insouthern Ontario (Aubry et al. 2007, p.2154). It is not known if these snowconditions existed historically in theGreat Lakes of the contiguous UnitedStates; however, the small number of

wolverine records from this areasuggests that they did not. It is possiblethat suitable snow conditions did reachfurther south in eastern Canada in 1850than they do today, making wolverinedispersal attempts from Canada to theGreat Lakes region of the contiguousUnited States more likely than they arenow. Wolverines occurred historicallyon Vancouver Island and have beengiven status as a separate subspecies bysome (Hall 1981, p. 109). TheVancouver Island population is nowregarded as possibly extirpated; nosightings have occurred since 1992

(COSEWIC 2003, p. 18).Wolverines in western Canada andAlaska appear to persist everywhere thathabitat and climate conditions aresuitable (COSEWIC 2003, pp. 1321;Aubry et al. 2007, pp. 21522155;Slough 2007, p. 79; Copeland et al.2010, Figure 2). Throughout this area,wolverines are managed by regulatedharvest at the Provincial and State level.Population estimates for Canada andAlaska are rough because no wolverinesurveys have taken place at the State orProvincial scale. However, the

population in western Canada isestimated to include approximately15,089 to 18,967 individuals (COSEWIC2003, p. 22). The number of wolverinesin Alaska is unknown, but they appearto exist at naturally low densities insuitable habitats throughout the state(Alaska Department of Fish and Game2004, pp. 1359). We have no

information to indicate that wolverinepopulations have been reduced innumbers or geographic range in Alaska.

The Complexity of Geographic RangeDelineation

Information on the nature of historicaland current locations of wolverine islacking for several reasons. Wolverinestend to live in remote and inhospitableplaces away from human settlements,where they are seldom encountered,documented, or studied. Wolverinesnaturally occur at low populationdensities and are rarely andunpredictably encountered where theydo occur. Wolverines often move longdistances in short periods of time; forexample, when dispersing from natalranges, wolverines may transit throughhabitats that are unsuitable for long-term survival (Aubry et al. 2007, p.2147; Moriarty et al. 2009, entire; Inmanet al. 2009, pp. 2228; Brian 2010, p. 3).Such movements make it difficult todistinguish with certainty betweenoccurrence records that representestablished populations in suitablehabitats and records that representshort-term occupancy or exploratorymovements without the potential for

establishment of home ranges,reproduction, or populations. Thesenatural attributes of wolverines make itdifficult to precisely determine theirpresent range, or trends in rangeexpansion or contraction, that may haveoccurred in the past. Therefore, we arecautious and use multiple lines ofevidence when trying to determinewhere past wolverine populationsoccurred.

Throughout the remainder of thisproposed rule, we focus on the use ofverifiable and documented wolverineoccurrence records to define historical

and present range as we havedetermined that these records constitutethe best scientific information availableon the past and present distribution ofwolverines (see Aubry et al. 2007, p.2148; McKelvey et al. 2008, entire).Verifiable records are records supported

by physical evidence such as museumspecimens, harvested pelts, DNAsamples, and diagnostic photographs.Documented records are those based onaccounts of wolverines being killed orcaptured. Use of only verifiable anddocumented records avoids mistakes of

misidentification often made ineyewitness accounts of visualencounters of unrestrained animals inthe wild. Visual-encounter records oftenrepresent the majority of occurrencerecords for elusive forest carnivores, andthey are subject to inherently high ratesof misidentification of the speciesinvolved, including wolverines

(McKelvey et al. 2008, pp. 551552).These misidentifications can result inwildly inaccurate conclusions aboutspecies occurrence (McKelvey et al.2008, pp. 550553).

Aubry et al. (2007, entire) used onlyverifiable and documented records toinvestigate wolverine distributionthrough time. This paper is the onlyavailable comprehensive treatment ofthese distribution patterns that attemptsto distinguish between records thatrepresent resident animals versusanimals that have dispersed outside ofsuitable habitat. For these reasons, we

find that Aubry et al. (2007, entire)represents the best available summary ofwolverine occurrence records in thecontiguous United States at this time.Since the publication of Aubry et al.(2007, entire), verified records ofwolverines have also been documentedin Colorado and California, which wewill describe in greater detail below.

Aubry et al. (2007, entire) usedverifiable and documented records frommuseum collections, literature sources,and State and Federal institutions totrace changes in geographic distributionof wolverines in the historical record.They then used an overlay of suitable

wolverine habitats to determine whichrecords represent wolverines in habitatsthat may support residency, and, byextension, populations, and whichrecords likely represent wolverinesoutside the range of suitable habitats, socalled extralimital records. Aubry etal.s (2007, entire) focus on verifiableand documented records corrected pastoverly broad approaches to wolverinerange mapping (Nowak 1973, p. 22; Hall1981, p. 1009; Wilson 1982, p. 644;Hash 1987, p. 576), which used a moreinclusive but potentially misleadingapproach when dealing with occurrence

records. Many of the extralimitalrecords used in these publicationsrepresented individuals that dispersedfrom natal ranges but ended up inhabitats that could not supportwolverines. Use of these data todetermine the historical geographicrange of wolverines results in grossoverestimation of the area that canactually be used successfully bywolverines for the establishment ofpopulations. Subsequent to publicationof Aubry et al. (2007, entire), twopublications (Copeland et al. 2010,



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entire; Brock et al. 2007, entire) furtherrefined our understanding of wolverinehabitat needs and corroborated theapproach of Aubry et al. (2007, entire).Thus, despite the paucity of verifiablerecords, we now have stronginformation on the areas that arecurrently suitable to be occupied bywolverine based on habitat and climate

conditions.We agree with Aubry et al. (2007, p.

2149) that the most appropriate methodto determine the current and historicalrange of wolverines is to use acombination of occurrence records andhabitat suitability, along with otherinformation, such as documentedsuccessful reproduction events,indicating where reproductive andpotentially self-sustaining populationsmay occur. We also generally agree withtheir conclusions about the historicaland current range of the species. Wefind that the species range is the area

that may support viable populations,and does not include extralimitaloccurrences outside of habitat that islikely to support wolverine life-historyneeds. Areas that can support wolverinepopulations may be referred to aspotential source populations becausethey provide surplus individualsthrough reproduction beyond what isneeded for replacement. Areas that havesome of the habitat attributes ofwolverine habitat but do not haveenough habitat to support viablepopulations may be referred to aspopulation sinks because wolverinesmay disperse to these areas and remain

for some time, but will either die therewithout reproducing, leave the area in

search of better habitat conditions, ormay actually reproduce, but at a ratelower than that needed for replacementof individuals lost to mortality oremigration, leading to eventualpopulation extinction.

For a widely dispersing species likethe wolverine, we expect many localityrecords to represent dispersal attempts

into sink habitats or nonhabitat. Thevalue to the population (and thus theDPS) of dispersers in these areas isunclear; it is likely that most dispersersinto sink habitats or nonhabitat will belost to the population unless they areable to move back into source habitats.Therefore, it is our conclusion thatpopulation sink areas and areas of non-wolverine habitat, here defined asplaces where wolverines may be found

but where habitat is not suitable forlong-term occupancy and reproduction,do not represent part of the specieshistorical range and have little

conservation value for the DPS, otherthan possibly serving as temporary stop-overs for attempted dispersers as theysearch for suitable habitats. Comparedwith broader approaches to defininghistorical geographic range, this focusedapproach (1) results in reducing the biasof extralimital dispersers and (2)concentrates conservation attention onareas capable of maintainingpopulations.

Aubry et al. (2007, pp. 21472148)divided records into historical(recorded prior to 1961), recent(recorded between 1961 and 1994), andcurrent (recorded after 1994).

Historical records occurred beforesystematic surveys. Historical records

encompass the time during whichwolverine numbers and distributionwere hypothesized to be at their highest(prior to European settlement) and alsoat their lowest (early 20th century)(Wright and Thompson 1935; Grinnellet al. 1937; Allen 1942; Newby andWright 1955, all as cited in Aubry et al.2007, p. 2148). The recent time intervalcovers a hypothesized populationexpansion and rebound from the early20th century low. Current records offerthe most recent evidence available forwolverine occurrences and potentialpopulations. All occurrence recordsmust be individually analyzed in lightof their context in terms of habitatconditions conducive to wolverinepopulation establishment and whetheror not they occur clustered with otherrecords, which might indicate thatpopulations have historically occurredin the area. The authors of Aubry et al.

(2007) did such an analysis as theycompiled their records.

Wolverine Distribution

We assessed the historical, recent, andcurrent distribution data for each of theregions below to determine thelikelihood of the presence of historicalpopulations (rather than extralimitaldispersers). Of 729 mappable records(those records with precise locationinformation) compiled by Aubry et al.(2007, p. 2150), 188 were from thehistorical time interval (see Table 1).The discussion below draws heavily

from both Aubry et al. (2007, entire) andCopeland et al. (2010, entire).

TABLE 1WOLVERINE RECORDS FROM THREE TIME PERIODS FROM AUBRY ET AL. 2007

[Numbers represent total documented and verifiable records with the subset of those records that were verifiable in parentheses]

Historical (1994)

Northeast ....................................................... 13 (1) 0 0Upper Midwest ............................................... 4 (2) 0 0Great Lakes ................................................... 36 (4) 1 0Central Great Plains ...................................... * 71 (2) 1 0Rocky Mountains ........................................... 147 (45) 332 (283) 215 (210)Pacific Coast .................................................. 89 (14) 23 (15) 7

Totals ...................................................... 362 (68) 357 (298) 222 (210)

* 35 records from a single source (the journals of Alexander Henry).

Northeast and Upper MidwestThelow number of records and scatterednature of their distribution combinedwith a lack of suitable habitat indicatethat wolverines were likely onlyoccasional transients to the area and notpresent as a reproducing populationafter 1800.

Great LakesThe lack of largenumbers of verifiable records in this

area of relatively high humanpopulation density and the lack ofsuitable habitat suggests that wolverinesdid not exist in this area as a viablepopulation after 1900. Widely scatteredrecords generally before 1900, alongwith occasional subsequent recordssuggest that if a reproducing populationexisted in the Great Lakes, it predated1900, and that any post-1900 records

represent dispersal from a recedingCanadian population. Wolverinedistribution in Ontario, Canada, appearsto have receded north from the GreatLakes region since the 1800s, andcurrently wolverines occupy only thenorthern portion of the province, adistance of over 644 km (400 mi) fromthe United States border (COSEWIC2003, p. 9). The distribution pattern of



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record illustrated in Aubry et al. (2007,p. 2152) is consistent with what would

be expected if those records were ofdispersing individuals from a Canadianpopulation that receded progressivelyfurther north into Canada after 1800,possibly due to natural climate changes(COSEWIC 2003, p. 28).

Central Great PlainsThe lack of

precise locality records and suitablehabitat from the Great Plains Statesleads us to conclude that reproducingpopulations of wolverines did nothistorically inhabit this area. Of thirty-six records from North Dakota, 35 arefrom the journals of a single fur trader(see Table 1), and it is not clear that therecords represent actual collectionlocalities or are localities where tradesor shipments occurred (Aubry 2007,pers. comm.). Given the habitatrelationships of wolverines (e.g.,Copeland et al. 2010, Figure 1), it isunlikely that these records represent

established wolverines or that this areaserved as wolverine habitat.Rocky MountainsFive Rocky

Mountains States (Idaho, Montana,Wyoming, Colorado, and Utah)contained numerous wolverine records.Records with precise localityinformation appear to coalesce aroundseveral areas that may have beenpopulation centers, such as centralColorado, the greater Yellowstoneregion, and northern Idaho-northwestern Montana. The largenumber of verifiable and documentedrecords for this region, along with thesuggestion of population centers or

strongholds, suggests that wolverinesexisted in reproducing populationsthroughout much of the RockyMountains during the historical timeinterval. The lack of records forColorado and Utah after 1921 suggeststhat the southern Rocky Mountainspopulation of wolverines was extirpatedin the early 1900s, concurrent withwidespread systematic predator control

by government agencies and livestockinterests. The northern RockyMountains population (north ofWyoming) was reduced to historicallows or possibly even extirpated during

the early 1900s, and then increaseddramatically in the second half of the1900s (see Table 1) as predator controlefforts subsided and trappingregulations became more restrictive(Aubry et al. 2007, p. 2151). Thisincrease likely indicates a populationrebound from historical lows in thisperiod.

Wolverine records from 1995 to 2005indicate that wolverine populationscurrently exist in the northern RockyMountains (see Table 1). Legal trappingin Montana in the recent past removed

an average of 10.5 individuals from thispopulation each year (MontanaDepartment of Fish, Wildlife, and Parks2007, p. 2), but harvest mortality has

been reduced due to regulatory changesin 2008 (Montana Department of Fish,Wildlife and Parks 2008, p. 8).Populations in British Columbia andAlberta, Canada, are extant (COSEWIC

2003, pp. 1819), and may have been asource of surplus wolverines to thecontiguous United States populationduring population lows. Recently, amale wolverine moved on its own fromthe southern Greater Yellowstone Areaof Wyoming into the southern RockyMountains of Colorado, where it stillpersisted as of November 2012 (Inmanet al. 2009, pp. 2226; Odell 2012, pers.comm.). This attempted dispersal eventis the first verified wolverine occurrencein Colorado since 1919 and mayrepresent a continuation of thewolverine expansion in the Rocky

Mountains detailed above. It is possiblethat other wolverines have traveled tothe southern Rocky Mountains and haveremained undetected. There is noevidence that Colorado currently hosts awolverine population or that femalewolverines have made, or are likely tomake, similar movements. Femaledispersal movements tend to be muchshorter than males, usually occupyinghome ranges adjacent to their natalrange, and dispersal is documented onlyfor lesser distances than males routinelytravel (Hornocker and Hash 1981, p.1290; Copeland 1996, p. 91; Kyle and

Strobeck 2001, p. 338; Tomasik andCook 2005, p. 390; Cegelski et al. 2006,p. 206, Inman et al. 2011, p. 7). Thelargest documented female movementoccurred in 2010 in the North Cascadesof Washington (Aubry et al. 2011, pp.2122). In that instance, a radio-collaredfemale wolverine moved an air-linedistance of approximately 233 km (145mi) over a 44-day period. During thismovement, her course generally stayedwithin suitable wolverine habitat (asdefined by Copeland et al. (2010, p.242)) and was never more than about 19km (12 mi) from suitable wolverinehabitat.

Pacific CoastHistorical recordsshow that wolverines occurred in twopopulation centers in the NorthCascades Range and the Sierra Nevada.However, records do not showoccurrences between these centers fromsouthern Oregon to northern California,indicating that the historicaldistribution of wolverines in this area is

best represented by two disjunctpopulations rather than a continuouspeninsular extension from Canada. Thisconclusion is supported by genetic data

indicating that the Sierra Nevada andCascades wolverines were separated forat least 2,000 years prior to extirpationof the Sierra Nevada population(Schwartz et al. 2007, p. 2174).

Only one Sierra Nevada record existsafter 1930, indicating that thispopulation was likely extirpated in thefirst half of the 1900s, concurrent with

widespread systematic predator controlprograms. In 2008, a male wolverinewas discovered in the Sierra NevadaRange of California, the first verifiedrecord from California since 1922(Moriarty et al. 2009, entire). Genetictesting revealed that this wolverine wasnot a descendant of the endemic SierraNevada wolverine population, but waslikely derived from wolverines in theRocky Mountains (Moriarty et al. 2009,p. 159). This attempted dispersal eventmay represent a continuation of thewolverine expansion in the contiguousUnited States as detailed above. Other

wolverines may have travelled to theSierra Nevada and remain undetected.There is no evidence that Californiacurrently hosts a wolverine populationor that female wolverines have made, orare likely to make, similar dispersalmovements.

Wolverines were likely extirpatedfrom the North Cascades in the early20th century and then recentlyrecolonized from Canada. Currently, asmall population persists in this area(Aubrey et al. 2011, entire). In 2012,reproduction was documented for thefirst time in the North Cascades (Aubryet al. 2012, p. 2). Wolverines have also

been documented in the southernportion of the North Cascades, nearMount Adams, since 2009 (Akins 2010,p. 4). The North Cascades populationmay be connected with, and is possiblydependent on, the larger Canadianpopulation for future expansion andlong-term persistence.

Summary of Wolverine Distribution

Historical wolverine records werefound across the northern tier of thecontiguous United States, withconvincing evidence of wolverinepopulations in the northern and

southern Rocky Mountains, SierraNevada Mountains, and North CascadesMountains (Aubry et al. 2007, p. 2152).

Currently, wolverines appear to bedistributed as functioning populationsin two regions in the contiguous UnitedStates: the North Cascades inWashington, and the northern RockyMountains in Idaho, Montana, andWyoming (this area also includes theWallowa Range in Oregon). Wolverineswere likely extirpated, or nearly so,from the entire contiguous United Statesin the first half of the 20th century



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(Aubry et al. 2007, Table 1). Althoughthe reasons for this extirpation are notknown with certainty, unregulatedtrapping and widespread indiscriminantpredator control likely contributed topopulation declines. The availableevidence suggests that, in the secondhalf of the 20th century and continuinginto the present time, wolverine

populations have expanded in the NorthCascades and the northern RockyMountains from sources in Canada, butthat populations have not beenreestablished in the Sierra NevadaRange or the southern Rocky Mountains,despite the known movement of singleindividual males to each of these areas.We conclude that the current range ofthe species in the contiguous UnitedStates includes the North CascadesMountains, the northern RockyMountains, the southern RockyMountains, and the Sierra NevadaMountains, but that reestablishment of

populations in the southern RockyMountains and Sierra NevadaMountains has not yet occurred.

We also conclude that wolverineseither did not exist as establishedpopulations, or were extirpated prior tosettlement and the compilation ofhistorical records, in the Great Lakesregion, possibly due to climate changesthat occurred through the 1800s and1900s. The Great Lakes region lackssuitable wolverine habitat, and suitablehabitat does not appear to exist inadjacent Canada (Copeland et al. 2010,Figure 1). The widely scattered recordsfrom this region are consistent with

dispersing individuals from a Canadianpopulation that receded north early inthe 1800s. We cannot rule out thepossibility that wolverines existed asestablished populations prior to theonset of trapping in this area, but wehave no evidence of this.

No evidence in the historical recordsindicates that wolverines were everpresent as established populations inthe Great Plains, Midwest, or Northeast.

Habitat Relationships and WolverineDistribution

Deep, persistent, and reliable spring

snow cover (April 15 to May 14) is thebest overall predictor of wolverineoccurrence in the contiguous UnitedStates (Aubry et al. 2007, pp. 21522156; Copeland et al. 2010, entire).Deep, persistent snow correlates wellwith wolverine year-round habitat useacross wolverine distribution in NorthAmerica and Eurasia at both regionaland local scales (Copeland et al. 2010,entire; Inman et al. 2012a, p. 785). It isuncertain why spring snow cover soaccurately predicts wolverine habitatuse; however, it is likely related to

wolverines need for deep snow duringthe denning period. In addition,wolverines appear to take advantage ofa cold, low-productivity niche by usingfood caching in cold habitats to survivefood-scarce winters that othercarnivores cannot (Inman et al. 2012b,pp. 640642). Wolverines physiologicalrequirement for year-round cold

temperatures may also play a role inhabitat use (Copeland et al. 2010, pp.242243). Snow cover during thedenning period is essential forsuccessful wolverine reproductionrange-wide (Hatler 1989, p. iv; Magounand Copeland 1998, p. 1317; Inman etal. 2007c, pp. 7172; Persson 2007;Copeland et al. 2010, p. 244). Wolverinedens tend to be in areas of highstructural diversity such as logs and

boulders with deep snow (Magoun andCopeland 1998, p. 1317; Inman et al.2007c, pp. 7172; Persson 2007, entire).Reproductive females dig deep snow

tunnels to reach the protective structureprovided by logs and boulders. Thisbehavior presumably protects thevulnerable kits from predation by largecarnivores, including other wolverines(Pulliainen 1968, p. 342; Zyryanov1989, pp. 312), but may also havephysiological benefits for kits by

buffering them from extreme cold, wind,and desiccation (Pullianen 1968, p. 342,Bjarvall et al. 1978, p. 23). Wolverineslive in low-temperature conditions andappear to select habitats in part to avoidhigh summer temperatures (Copeland etal. 2010, p. 242). Wolverine distribution

is likely affected by climatic conditionsat two different scales. Wolverinesrequire deep persistent snow fordenning, and this likely determineswhere wolverine populations can befound at the grossest range-wide scale(Copeland et al. 2010, p. 244). Atsmaller scales, wolverines likely selecthabitats to avoid high summertemperatures. These cool habitats alsotend to retain snow late into spring,leading to wolverines year-roundassociation with areas of persistentspring snow (Copeland et al. 2010, p.244).

All of the areas in the contiguousUnited States for which good evidenceof persistent wolverine populations(either present or historical) exists (i.e.,North Cascades, Sierra Nevada, northernand southern Rocky Mountains) containlarge and well-distributed areas of deepsnow cover that persists through thewolverine denning period (Inman et al.2011, Fig. 3; Aubry et al. 2007, p. 2154;Copeland et al. 2010, Figure 1). TheGreat Plains, Great Lakes, Midwest, andNortheast lack the spring snowconditions and low summer

temperatures thought to be required bywolverines for successful reproductionand year-round occupancy (Aubry et al.2007, p. 2154; Copeland et al. 2010,Figure 1). The lack of persistent springsnow conditions in the Great Plains,Great Lakes, Midwest, and Northeastsupports the exclusion of these areasfrom the current range of wolverines.

Whether wolverines once existed asestablished populations in any of theseregions is uncertain, but the currentclimate appears to preclude theirpresence as reproducing populations,and the sparse historical record ofwolverine presence in this area makeshistorical occupation of these areas bywolverine populations doubtful. It isour conclusion that the ecosystem thatsupports wolverines does not exist inthese areas currently, and may not haveexisted at the time of Europeansettlement of these areas.

Large areas of habitat with

characteristics suitable for wolverinesstill occur in the southern RockyMountains and Sierra Nevada, despitethe extirpation of wolverines from thoseareas (Aubry et al. 2007, p. 2154, Inmanet al. 2011, Fig. 4; Copeland et al. 2010,Figure 1). Wolverine extirpations inthese areas were coincident withunregulated trapping and systematicpredator eradication efforts in the early1900s, which have been discontinuedfor many years. Each of these areas hasreceived at least one and possibly moremigrants from adjacent populations inthe northern Rocky Mountains;however, there is no evidence that

females have migrated to these areas orthat populations of wolverines currentlyexist there (Aubry et al. 2007, Table 1;Moriarty et al. 2009, entire; Inman et al.2009, entire).

We conclude that areas of wolverinehistorical occurrence can be placed inone of three categories: (1) Areas wherewolverines are extant as reproducingand potentially self-sustainingpopulations (North Cascades, northernRocky Mountains); (2) areas wherewolverines historically existed asreproducing and potentially self-sustaining populations prior to human-

induced extirpation, and wherereestablishment of those populations ispossible given current habitatconditions and management (the SierraNevada Mountains in California andsouthern Rocky Mountains in Colorado,New Mexico, Wyoming, UintaMountains and surrounding ranges inUtah, Bighorn Mountains in Wyoming,and possibly the Oregon CascadesMountains); and (3) areas wherehistorical presence of wolverines inreproducing and potentially self-sustaining populations is doubtful, and



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where the current habitat conditionspreclude the establishment ofpopulations (Great Plains, Midwest,Great Lakes, and Northeast). We,therefore, consider the current range ofwolverines to include suitable habitat inthe North Cascades of Washington, thenorthern Rocky Mountains of Idaho,Wyoming, Montana, and eastern

Oregon, the southern Rocky Mountainsof Colorado and Wyoming, and theSierra Nevada of California. We hereinclude the Sierra Nevada and southernRocky Mountains in the current range ofwolverines despite the probability thatfunctional populations do not exist inthese areas. They are included due tothe known existence of one individualin each area and the possibility thatmore, as yet undetected, individualsinhabit these areas.

Distinct Population Segment

Pursuant to the Act, we must considerfor listing any species, subspecies, or,for vertebrates, any Distinct PopulationSegment (DPS) of these taxa, if there issufficient information to indicate thatsuch action may be warranted. Tointerpret and implement the DPSprovision of the Act and Congressionalguidance, the Service and the NationalMarine Fisheries Service published, onFebruary 7, 1996, an interagency PolicyRegarding the Recognition of DistinctVertebrate Population Segments underthe Act (61 FR 4722). This policyaddresses the recognition of DPSs forpotential listing actions. The policyallows for more refined application of

the Act that better reflects the biologicalneeds of the taxon being considered,and avoids the inclusion of entities thatdo not require its protective measures.

Under our DPS policy, three elementsare considered in a decision regardingthe status of a possible DPS asendangered or threatened under the Act.These are applied similarly foradditions to the list of endangered andthreatened species, reclassification, andremoval from the list. They are: (1)Discreteness of the population segmentin relation to the remainder of the taxon;(2) the biological or ecological

significance of the population segmentto the taxon to which it belongs; and (3)the population segments conservationstatus in relation to the Acts standardsfor listing (i.e., whether the populationsegment is, when treated as if it were aspecies or subspecies, an endangered orthreatened species). Discreteness refersto the degree of isolation of a populationfrom other members of the species, andwe evaluate this factor based on specificcriteria. If a population segment isconsidered discrete, we must considerwhether the discrete segment is

significant to the taxon to which itbelongs by using the best availablescientific and commercial information.If we determine that a populationsegment is both discrete and significant,we then evaluate it for endangered orthreatened species status based on theActs standards. The DPS evaluation inthis proposed rule concerns the segment

of the wolverine species occurringwithin the contiguous 48 States,including the northern and southernRocky Mountains, Sierra Nevada Range,and North Cascades Range.

Distinct Population Segment Analysisfor Wolverine in the Contiguous UnitedStates

Analysis of Discreteness

Under our DPS Policy, a populationsegment of a vertebrate species may beconsidered discrete if it satisfies eitherone of the following conditions: (1) It ismarkedly separated from other

populations of the same taxon as aconsequence of physical, physiological,ecological, or behavioral factors(quantitative measures of genetic ormorphological discontinuity mayprovide evidence of this separation); or(2) it is delimited by internationalgovernmental boundaries within whichdifferences in control of exploitation,management of habitat, conservationstatus, or regulatory mechanisms existthat are significant in light of section4(a)(1)(D) of the Act (inadequacy ofexisting regulatory mechanisms). Thewolverine within the contiguous United

States meets the second DPSdiscreteness condition because ofdifferences in conservation status asdelimited by the Canadian-United Statesinternational governmental boundary.

In our 12-month finding for the NorthAmerican wolverine DPS (75 FR 78030)we conducted a complete analysis of thediscreteness of the wolverine DPS thatwe incorporate here by reference. In thatanalysis we concluded that theinternational boundary between Canadaand the United States currently leads todivision of the control of exploitationand conservation status of the

wolverine. This division is significantbecause it allows for potentialextirpation of the species within thecontiguous United States through loss ofsmall populations and lack ofdemographic and genetic connectivityof the two populations. This differencein conservation status is likely to

become more significant in light ofthreats discussed in the five factorsanalyzed below. Therefore, we find thatthe difference in the conservationstatuses in Canada and the United Statesresult in vulnerability to the significant

threat (discussed below) in the U.S.wolverine population but not for theCanadian population. Existingregulatory mechanisms are inadequateto ensure the continued existence ofwolverines in the contiguous UnitedStates in the face of these threats.Therefore, it is our determination thatthe difference in conservation status

between the two populations issignificant in light of section 4(a)(1)(D)of the Act, because existing regulatorymechanisms appear sufficient tomaintain the robust conservation statusof the Canadian population, whileexisting regulatory mechanisms in thecontiguous United States areinsufficient to protect the wolverinefrom threats due to its depletedconservation status. As a result, thecontiguous United States population ofthe wolverine meets the discretenesscriterion in our DPS Policy (61 FR4725). Consequently, we use the

international border between the UnitedStates and Canada to define thenorthern boundary of the contiguousUnited States wolverine DPS.

Analysis for Significance

If we determine a population segmentis discrete, its biological and ecologicalsignificance will then be considered inlight of Congressional guidance that theauthority to list DPSs be used sparinglywhile encouraging the conservation ofgenetic diversity. In carrying out thisexamination, we consider availablescientific evidence of the populations

importance to the taxon to which itbelongs (i.e., the North Americanwolverine (Gulo gulo luscus)). Our DPSpolicy states that this consideration mayinclude, but is not limited to: (1)Persistence of the discrete populationsegment in an ecological setting unusualor unique for the taxon; (2) evidencethat loss of the discrete populationsegment would result in a significantgap in the range of the taxon; (3)evidence that the discrete populationsegment represents the only survivingnatural occurrence of a taxon that may

be more abundant elsewhere as anintroduced population outside itshistorical range; or (4) evidence that thediscrete population segment differsmarkedly from other populations of thespecies in its genetic characteristics.

In our 12-month finding (75 FR78030), we conducted an exhaustiveanalysis of the significance of thecontiguous United States population ofthe North American wolverine that weincorporate here by reference. In thatanalysis we concluded that thewolverine population in the contiguousUnited States is significant because its



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loss would result in a significant gap inthe range of the taxon.

Summary of the Distinct PopulationSegment Analysis

We conclude that the wolverinepopulation in the contiguous UnitedStates is both discrete and significantunder our DPS policy. The conservation

status of wolverines in the contiguousUnited States is less secure thanwolverines in adjacent Canada due tofragmented habitat, small populationsize, reduced genetic diversity, and theirvulnerability to threats analyzed in thisfinding. Loss of the contiguous UnitedStates wolverines would result in asignificant gap in the range of the taxon.Therefore, we determine that thepopulation of wolverines in thecontiguous 48 States, as currentlydescribed, meets both the discretenessand significance criteria of our DPSpolicy, and is a listable entity under theAct as a DPS.

Summary of Factors Affecting theSpecies

Section 4 of the Act (16 U.S.C. 1533),and its implementing regulations at 50CFR part 424, set forth the proceduresfor adding species to the Federal Listsof Endangered and Threatened Wildlifeand Plants. Under section 4(a)(1) of theAct, we may list a species based on anyof the following five factors: (A) Thepresent or threatened destruction,modification, or curtailment of itshabitat or range; (B) overutilization forcommercial, recreational, scientific, or

educational purposes; (C) disease orpredation; (D) the inadequacy ofexisting regulatory mechanisms; and (E)other natural or manmade factorsaffecting its continued existence. Listingactions may be warranted based on anyof the above threat factors, singly or incombination. Each of these factors isdiscussed below.

Factor A. The Present or ThreatenedDestruction, Modification, orCurtailment of Its Habitat or Range

Under Factor A we will discuss avariety of impacts to wolverine habitat

including: (1) Climate change, (2)human use and disturbance, (3)dispersed recreational activities, (4)infrastructure development, (5)transportation corridors, and (6) landmanagement. Many of these impactcategories overlap or act in concert witheach other to affect wolverine habitat.Climate change is discussed underFactor A because although climatechange may affect wolverines directly

by creating physiological stress, theprimary impact of climate change onwolverines is expected to be through

changes to the availability anddistribution of wolverine habitat.

Two efforts to map wolverine habitatin the contiguous United States have

been completed (Inman et al. 2012,entire; Copeland et al. 2010, entire).Both of these habitat models rely onsnow as a primary input. The Copelandet al. (2010) model defines wolverine

habitat as simply the area continuouslycovered by snow from mid-winter untilmid-May. The Inman et al. (2012) modelis based on snowpack and alsoincorporates other habitat variables,such as terrain ruggedness and someaspects of human development. The twomodels result in estimates of wolverinehabitat that are very similar across mostof the range of wolverines in thecontiguous United States. Areas ofsignificant departure between themodels are the California Sierras andOregon Cascades where the Copeland etal. (2010) model predicts significantly

greater habitat area than does the Inmanet al. (2012) model. Given the generalagreement between the two models, wecombined the areas depicted by theminto a composite wolverine habitatmodel that includes all areas described

by one or both of these models. Thiscomposite model serves as the basis forour estimates of wolverine habitat

below. Within the four States thatcurrently harbor wolverines (Montana,Idaho, Oregon (Wallowas) andWyoming), an estimated 124,014 km2(47,882 mi2) of wolverine habitat exists.Habitat in the North Cascades andEastern Washington (Kettle Range and

associated habitat) add approximately20,356 km2 (7859 mi2). Ninety-fourpercent (135,396 km2; 52,277 mi2) oftotal wolverine habitat is in Federalownership with most of that managed

by the U.S. Forest Service (ForestService).

Reduction in Habitat Due to ClimateChange

Our analyses under the Act includeconsideration of ongoing and projectedchanges in climate. The terms climateand climate change are defined by theIntergovernmental Panel on Climate

Change (IPCC). Climate refers to themean and variability of different typesof weather conditions over time, with 30years being a typical period for suchmeasurements, although shorter orlonger periods also may be used (IPCC2007, p. 78). The term climate changethus refers to a change in the mean orvariability of one or more measures ofclimate (e.g., temperature orprecipitation) that persists for anextended period, typically decades orlonger, whether the change is due tonatural variability, human activity, or

both (IPCC 2007, p. 78). Various typesof changes in climate can have direct orindirect effects on species. These effectsmay be positive, neutral, or negative andthey may change over time, dependingon the species and other relevantconsiderations, such as the effects ofinteractions of climate with othervariables (e.g., habitat fragmentation)

(IPCC 2007, pp. 814, 1819).We recognize that there are scientific

uncertainties on many aspects ofclimate change, including the role ofnatural variability in climate. In ouranalysis, we rely both on synthesisdocuments (e.g., IPCC 2007; Karl et al.2009) that present the consensus view ofa very large number of experts onclimate change from around the world,and on five analyses that relate theeffects of climate changes directly towolverines (Gonzalez et al. 2008, entire;Brodie and Post 2009, entire; Peacock2011, entire; McKelvey et al. 2011,

entire, Johnston et al. 2012, entire). Todate, McKelvey et al. (2011) is the mostsophisticated analysis regarding climatechange effects to wolverines. This reportis based on data from global climatemodels including both temperature andprecipitation, downscaled to reflect theregional climate patterns andtopography found within the range ofwolverines in the contiguous UnitedStates. For this reason we find thatMcKelvey et al. (2011, entire) representsthe best scientific information availableregarding the impacts of climate changeto wolverine habitat.

Snowpack changes as well as

concomitant changes to wolverinehabitat suitability result from bothchanges in temperature (negativerelationship) and changes in snowfall(positive relationship). Because manyclimate models predict higherprecipitation levels associated withclimate warming, the interaction

between these two variables can bequite complex. Consequently,predictions about snow coverage thatrely only on temperature projections areless reliable than those that rely on bothtemperature and precipitation.McKelvey et al. (2011, entire) report

projections for wolverine habitat anddispersal routes through the timeinterval from 2070 to 2099.

Climate Effects to Wolverines

Due to dependence of wolverines ondeep snow that persists into late spring

both for successful reproduction and foryear-round habitat, and their restricteddistribution to areas that maintainsignificant snow late into the springseason, we conclude that deep snowmaintained through the denning periodis required for wolverines to



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successfully live and reproduce.Reduction of this habitat feature wouldproportionally reduce wolverine habitat,or to an even greater extent if habitatreduction involved increasingfragmentation.

Based on the information describedabove, we analyzed the effects ofclimate change on wolverines through

three primary mechanisms: (1) Reducedsnowpack and earlier spring runoff,which would reduce suitable habitat forwolverine denning; (2) increase insummer temperatures beyond thephysiological tolerance of wolverines;and (3) ecosystem changes due toincreased temperatures, which wouldmove lower elevation ecosystems tohigher elevations, thereby eliminatinghigh-elevation ecosystems on whichwolverines depend and increasingcompetitive interactions with speciesthat currently inhabit lower elevations.These mechanisms would tend to push

the narrow elevation band thatwolverines use into higher elevation.Due to the conical structure ofmountains, this upward shift wouldresult in reduced overall suitable habitatfor wolverines.

Reduced Snow Pack and Earlier SpringRunoff

Warmer winter temperatures arereducing snow pack in western NorthAmerican mountains through a higherproportion of precipitation falling asrain and higher rates of snowmeltduring winter (Hamlet and Lettenmaier1999, p. 1609; Brown 2000, p. 2347;

Mote 2003, p. 31; Christensen et al.2004, p. 347; Knowles et al. 2006, pp.45484549). This trend is expected tocontinue with future warming (Hamletand Lettenmaier 1999, p. 1611;Christensen et al. 2004, p. 347; Mote etal. 2005, p. 48). Shifts in the initiationof spring runoff toward earlier dates arealso well documented (Hamlet andLettenmaier 1999, p. 1609; Brown 2000,p. 2347; Cayan et al. 2001, pp. 409410;Christensen et al. 2004, p. 347; Mote etal. 2005, p. 41; Knowles et al. 2006, p.4554). Earlier spring runoff leads to lackof snow or degraded snow conditions

during April and May, the critical timeperiod for wolverine reproductivedenning. In addition, a feedback effecthastens the loss of snow cover due tothe reflective nature of snow and therelative heat-absorbing properties ofnon-snow-covered ground. This effectleads to the highest magnitude ofwarming occurring at the interface ofsnow-covered and exposed areas,increasing the rate at which meltingoccurs in spring (Groisman et al. 1994a,pp. 16371648; Groisman et al. 1994b,pp. 198200). Due to the importance of

deep snow cover in spring for wolverinereproduction, currently suitable habitatthat loses this feature would berendered unsuitable for wolverines.

Ecosystem Changes Associated withClimate Change

Changes in temperature and rainfallpatterns are expected to shift the

distribution of ecosystems northward(IPCC 2007c, p. 230) and up mountainslopes (McDonald and Brown 1992, pp.411412; Danby and Hik 2007, pp. 358359; IPCC 2007c, p. 232). As climatechanges over a landscape, theecosystems that support wolverines arelikely to move according to the changeof temperature, but with a time lagdepending on the ability of individualplant species to migrate (McDonald andBrown 1992, pp. 413414; Hall andFagre 2003, p. 138; Peterson 2003, p.652). Wolverines are not dependent onany particular ecosystem in the sensethat they do not appear to depend on acertain vegetative component or other

biological ecosystem attribute; however,it is likely that wolverines wouldrespond to similar climatic cues as othermembers of the alpine ecosystem suchthat changes in tree-line location up ordown slope would predict a similarchange in wolverine distribution.Because of their reliance onmountainous habitat, wolverines in thecontiguous United States will mostlikely adjust to climate changes by usinghigher elevations on mountain slopes,not by shifting their latitudinaldistribution. Along a latitudinal

gradient through the historicaldistribution of wolverines, records te

endangered and threatened wildlife and plants; threatened status for the distinct population segment...

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