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: Scientific [common] Marmota caligata [Hoary ] Forest: Salmon–Challis National Forest Forest Reviewer: Mary Friberg Date of Review: 2/8/2018 Forest concurrence (or recommendation if new) for inclusion of species on list of potential SCC: (Enter Yes or No)

FOREST REVIEW RESULTS:

1. The Forest concurs or recommends the species for inclusion on the list of potential SCC: Yes___ No___

2. Rationale for not concurring is based on (check all that apply): Species is not native to the plan area ______Species is not known to occur in the plan area ______Species persistence in the plan area is not of substantial concern ______

FOREST REVIEW INFORMATION:

1. Is the Species Native to the Plan Area? Yes_X__ No___

If no, provide explanation and stop assessment.

2. Is the Species Known to Occur within the Planning Area? Yes_X__ No___

If no, stop assessment. Table 1. All Known Occurrences, Years, and Frequency within the Planning Area Year Observed Number of Location of Observations (USFS Source of Information Individuals District, Town, River, Road Intersection, HUC, etc.)

2011, 2013 15 North Fork Ranger District Waterbury, B. 2017. Personal communication with Beth Waterbury, Salmon Region wildlife biologist for the Department of Fish and Game. September 11, 2017.

2016 10 Leadore Ranger District Waterbury, B. 2017. Personal communication with Beth Waterbury, Salmon Region wildlife biologist for the Idaho Department of Fish and Game. September 11, 2017.

a. Are all Species Occurrences Only Accidental or Transient?

Yes___ No_X__

If yes, document source for determination and stop assessment. b. For species with known occurrences on the Forest since 1990, based on the number of observations and/or year of last observation, can the species be presumed to be established or becoming established in the plan area?

Yes_X__ No___

If no, provide explanation and stop assessment

c. For species with known occurrences on the Forest predating 1990, does the weight of evidence suggest the species still occurs in the plan area?

Yes___ No___

Provide explanation for determination

N/A – occurrences have been documented since 1990.

If determination is no, stop assessment

d. Map 1, range in Idaho (IDFG 2017)

IDFG (Idaho Department of Fish and Game). 2017a. Hoary marmot (Marmota caligata). Internet website: https://idfg.idaho.gov/species/taxa/17870. Accessed on September 8, 2017.

Map 2, Hoary marmot range in (MNHP and MFWP 2017)

MNHP and MFWP (Montana Natural Heritage Program and Montana Fish, Wildlife, and Parks). 2017. Montana Field Guides – Hoary marmot (Marmota caligata). Internet website: http://fieldguide.mt.gov/speciesDetail.aspx?elcode=AMAFB03040. Accessed on September 8, 2017.

e. Map 3, Hoary marmot occurrences on the Salmon–Challis National Forest (Waterbury, B. 2017. Personal communication with Beth Waterbury, Salmon Region wildlife biologist for the Idaho Department of Fish and Game. September 11, 2017)

3. Is There Substantial Concern for the Species’ Capability to persist Over the Long-term in the Plan Area Based on Best Available Scientific Information?

Table 2. Status summary based on existing conservation assessments

Entity Status/Rank (include definition if Other) NatureServe G5—Secure (Common; widespread and abundant) Global Rank NatureServe S4—Apparently secure (Uncommon but not rare; some cause for long-term concern due to declines or other factors) State Rank State List IDAPA: Protected nongame Status SGCN Tier 3 (Species that do not meet criteria for tier 1 or 2, yet still have conservation needs. In general, these species are relatively more common, but commonness is not the sole criterion and often these species have either declining trends rangewide or are lacking in information; Rationale: threats to habitat, data deficient) USDA Forest Not Region 1 or 4 sensitive Service USDI FWS Not listed Other Not BLM Type 2

Table 3. Status summary based on best available scientific information.

Species (Scientific and Common Name): Marmota caligata (Hoary marmot)

Criteria Rank Rationale Literature Citations 1 A3 Range maps suggest the hoary marmot is a year-round resident in the IDFG (Idaho Department of Fish and Distribution on northern portion of the Forest (Map 1). Observation on the Forest have all Game). 2017. Idaho State Wildlife Salmon–Challis been made by Idaho Fish and Game (IDFG) within the last decade and all Action Plan, 2015. Boise, ID. National Forest are in the Beaverhead Mountains on the North Fork and Leadore Ranger Districts (Table 1). However, suitable habitat likely exists within the Salmon River, Lemhi, Pahsimeroi, and Pioneer Mountain Ranges. Based on observations and the distribution of alpine habitat on the Forest, populations are likely naturally distributed as isolated patches with limited opportunity for dispersal among mountain ranges, although within range dispersal is possible (Rank A3). Confidence is moderated by the lack of surveys for Hoary Marmot on the Salmon-Challis.

Confidence in Rank: High, Medium, or Low 2 C Hoary marmot have an extensive distribution (Rank C) occur in Central and Braun. J.K., T.S. Eaton, Jr., and M.A. Distribution in mainland Southeast , the Territory, western Northwest Mares. 2011. Marmota caligata surrounding Territory, central and northern , the Cascade Mountains of (Rodentia: Sciuridae). Mammalian geographic area and southern British Columbia, the Mountains of central and Species. 43(884):155–171. northern Idaho, and the of Alberta and western Montana IDFG (Idaho Department of Fish and (Braun et al. 2011; NatureServe 2017). Hoary are poorly Game). 2017. Idaho State Wildlife documented in Idaho, with sparse observations from the Selkirk, Bitterroot, Action Plan, 2015. Boise, ID. Beaverhead, Boulder, White Cloud, and Salmon River mountain ranges

(IDFG 2017). Central Idaho and western Montana represent the southern NatureServe. 2017. NatureServe limits of the species range. Explorer: An online encyclopedia of

life [web application]. Version 7.1. Confidence in Rank: High, Medium, or Low NatureServe, Arlington, Virginia. Internet website: http://explorer.natureserve.org.

Species (Scientific and Common Name): Marmota caligata (Hoary marmot)

Accessed on September 8, 2017. 3 B Hoary marmots are non-migratory (NatureServe 2017), but the species’ Armitage, K.B. 2013. Climate change Dispersal Capability range is the greatest of any , spanning over 20° latitude, and the conservation of marmots. which suggests ability for dispersal (Kerhoulas 2015). We are not aware of Natural Science. 5 (5A): 36–43. reports of dispersal distances by the hoary marmot. The similar (Marmota vancouverensis) has been documented dispersing Bryant, A. 1996. Reproduction and 4.6 miles (Bryant 1996). The longest dispersal by the marmot genera is by persistence of Vancouver Island the yellow-bellied marmot (Marmota flaviventris), which are known to marmots (Marmota vancouverensis) disperse up to 9.3 miles (Van Vuren 1990 in Armitage 2013). Sex-biased in natural and logged habitats. Can. J. dispersal favoring male marmots has been documented, but there is no Zool. 74:678-687. empirical data to suggest that males can cross barriers that females cannot, only that males may disperse more often (Kyle et al. 2007). Increasing Griffin, S.C., P.C. Griffin, M.L. Taper, latitude and altitude are correlated with delayed dispersal of young, and and L.S. Mills. 2009. Marmots on the social organization may also strongly influence the time of dispersal (Kyle et move? Dispersal in a declining al. 2007). montane . Journal of Mammalogy, 90, 686-695. Dispersal may become limited as habitats become more fragmented under increased aridity and tree encroachment associated with a warming Kerhoulas, N.J., A.M. Gunderson, and climate (Armitage 2013; Griffin 2009). Therefore, hoary marmots probably L.E. Olson. 2015. Complex history of have a moderate ability for dispersal that is limited by suitable habitat isolation and gene flow in hoary, (Rank B). olympic, and endangered vancouver island marmots. Journal of Confidence in Rank: High, Medium, or Low Mammalogy, 96(4), 810-826.

Kyle, C.J., et al. 2007. Social structure and facultative mating systems of hoary marmots (Marmota caligata). Molecular Ecology 16:1245-1256.

Species (Scientific and Common Name): Marmota caligata (Hoary marmot)

NatureServe. 2017. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Internet website: http://explorer.natureserve.org. Accessed on September 8, 2017. 4 B Systematic surveys for the hoary marmot have not been conducted on the MNHP and MFWP (Montana Natural Abundance on the Salmon-Challis. Relative densities on nearby habitat in Montana are Heritage Program and Montana Fish, Salmon–Challis generally low (MNHP and MFWP 2017). Limited observations on the Forest Wildlife, and Parks). 2017. Montana National Forest and nearby and availability of habitat suggest the species may be Field Guides – Hoary marmot uncommon (Rank B). However, the low accessibility of the specie’s habitat (Marmota caligata). Internet may make the species underreported compared to its true abundance. website: http://fieldguide.mt.gov/speciesDetai Confidence in Rank: High, Medium, or Low l.aspx?elcode=AMAFB03040. Accessed on September 8, 2017. 5 D The hoary marmot is thought to maintain stable populations range-wide Braun. J.K., T.S. Eaton. Jr., and M.A. Population Trend on (Braun et al. 2011), but the short- and long-term population trends in Idaho Mares. 2011. Marmota caligata the Salmon–Challis are unknown (IDFG 2017). Because no population surveys have been (Rodentia: Sciuridae). Mammalian National Forest conducted on the Forest, information is insufficient to assess this criterion Species. 43(884):155–171. (Rank D). IDFG (Idaho Department of Fish and

Game). 2017. Idaho State Wildlife Confidence in Rank: High, Medium, or Low Action Plan, 2015. Boise, ID. 6 B Hoary marmots are alpine specialists. They can be found in coastal tundra ADFG (Alaska Department of Fish and Habitat Trend on the on the north slope of Alaska as well. Dens are located in large boulder Game). 2018. Hoary Marmot Salmon–Challis fields, talus slopes, and rock slides adjacent to alpine or subalpine mesic (Marmota caligata) Species Profile. National Forest meadows for foraging (IDFG 2017). Their diet consists of grasses, sedges, Internet website: forbs, , , and willows (Burt and Grossenheider 1976 in http://www.adfg.alaska.gov/index.cf

Species (Scientific and Common Name): Marmota caligata (Hoary marmot)

NatureServe 2017; Hansen 1975). Denning habitat must contain rocks large m?adfg=hoarymarmot.main. enough and accumulated to a depth sufficient to provide protection from Accessed 1/25/2018. predators as , , and will dig for them (ADFG 2018). Other important attributes include a eastern to southern exposure with Armitage, K. B. 2013. Climate change earlier snow melt relative to northern or western exposures, and a and the conservation of marmots. moderate to steep slope that provides good drainage (Armitage 2013). Natural Science. 5 (5A): 36–43.

Approximately 1% of the Forest is classified as alpine and 3% as barren-rock IDFG (Idaho Department of Fish and based on Landfire biophysical settings (USFS 2017). Within these alpine Game). 2017. Idaho State Wildlife systems, approximately 13% of the vegetation is considered mesic Action Plan, 2015. Boise, ID. meadows (USFS 2017b); these areas and the edges of high-elevation lakes and associated hanging valley may provide foraging habitat for the NatureServe. 2017. NatureServe marmots. Because alpine vegetation and barren rock mainly occur in Explorer: An online encyclopedia of designated wilderness, roadless, or remote areas where human life [web application]. Version 7.1. disturbance is minimal, alpine communities of the Salmon–Challis are NatureServe, Arlington, Virginia. considered to exhibit good integrity and are relatively stable (Rank B; USFS Internet website: 2017). Although these systems are rare and unique, they are well http://explorer.natureserve.org. represented on the Forest (USFS 2017). Encroachment of woody plants into Accessed on September 8, 2017. subalpine meadows has been observed on the Forest, but there is no data on the extent and this uncertainty moderates our confidence in this rank. USFS (United States Department of Agriculture, Forest Service). 2017. Confidence in Rank: High, Medium, or Low Salmon–Challis National Forest Data Assessment, Terrestrial Ecosystems Section (Draft). _____. 2017b. Data on file (20171201_SCVeg_FRG_VCC.xlsx). Salmon-Challis National Forest, Salmon, ID.

Species (Scientific and Common Name): Marmota caligata (Hoary marmot)

7 A The greatest threat to the hoary marmot is climate warming. Evidence of Armitage, K. B. 2013. Climate change Vulnerability of the potential impacts of climate warming on marmot populations is seen in and the conservation of marmots. Habitats on the the reduction in the geographic distribution of several marmot species Natural Science. 5 (5A): 36–43. Salmon–Challis under global warming since the last ice age (Armitage 2013). National Forest Behrens, P.N., R.E. Keane, D.L. To project the future climate and impacts to resources in the Peterson, and J.J. Ho. 2018. Chapter Intermountain Region including the Salmon-Challis, the Intermountain 6: effects of climatic variability and Adaptation Partnership (IAP) used Representative Concentration Pathway change on forest vegetation. In [RCP] 4.5 and 8.5, which capture a moderate and high future warming, Halofsky, J.E., D.L. Peterson, J.J. Ho, respectively (Halofsky et al. 2018). Although pathways predicting lower N.L. Little, L.A. Joyce, editors. 2018. warming exist, the 4.5 and 8.5 pathways were chosen by the IAP because Climate change vulnerability and they are, in comparison, well studied providing a large set of projections adaptation in the Intermountain that enhance our understanding of the possible range in future climate. Region. Gen. Tech. Rep. RMRS-GTR- Thus, this represents best available science for our Forest with regard to a xxx. Fort Collins, CO: US Department warming climate. of Agriculture, Forest Service, Rocky Mountain Research Station. Xxx p. Although uncertainty exists about the magnitude and rate of climate change (For a discussion of this see Behrens et al. 2018), warming Ge, Y. and G. Gong. 2009. Land temperatures are the most certain consequence of increased CO2 in the surface insulation response to snow atmosphere. By 2100, median minimum and maximum temperature in the depth variability. J. Geophys. Res. Middle Rockies subregion, which includes the Salmon-Challis, is projected 115, D08107, to rise about 5-6˚F under the moderate warming scenario and about 10˚F doi:10.1029/2009JD012798. under the high warming scenario. Regardless of scenario, the greatest departure from historical seasonal minimum temperatures occurs in the Griffin, S.C., P.C. Griffin, M.L. Taper, summer. Annual precipitation projections are highly variable with no and L.S. Mills. 2009. Marmots on the discernible trend under moderate warming and a slight increasing trend move? Dispersal in a declining with high warming (Joyce and Talbert 2018). Even with increased montane mammal. Journal of precipitation, snowpack depth and persistence is projected to be reduced, Mammalogy, 90, 686-695. although impacts on the Salmon-Challis may be markedly less compared to other areas of the Intermountain Region (Muir et al. 2018). In addition, Halofsky, J.E., D.L. Peterson, J.J. Ho,

Species (Scientific and Common Name): Marmota caligata (Hoary marmot)

because of the complexity of the terrain microsites of adequate snow N.L. Little, L.A. Joyce, editors. 2018. depth may remain. Shallower snowpack and earlier snowmelt could put Climate change vulnerability and hoary marmots at greater risk to as has been observed in adaptation in the Intermountain Olympic marmots (Marmota olympus) (Armitage 2013). A minimum snow Region. Gen. Tech. Rep. RMRS-GTR- depth of >8 inches may be required to insulate dens from ambient air xxx. Fort Collins, CO: US Department temperatures (Danby and Hik 2007 in Patil et al. 2013; Ge and Gong 2009). of Agriculture, Forest Service, Rocky More may be needed depending on the moisture content. Snow depth at Mountain Research Station. Xxx p. long-term study sites of the hoary marmot in the relatively dry and cold Yukon Territory range from 4 to 24 inches (Kyle et al 2007, Danby and Hik IDFG (Idaho Department of Fish and 2007, and Environment Canada weather archives Game). 2017. Idaho State Wildlife (http://weatheroffice.gc.ca) in Patil et al. 2013). Projections for the RCP 4.5 Action Plan, 2015. Boise, ID. scenario are not available, but under RCP 8.5 scenario 8-16 inch depth snowpack on April 1 is projected to remain extensively distributed across Joyce, L. A., Talbert, M. 2018. Chapter the Forest and deeper snowpack will remain in all major mountain ranges 3: Historical and Projected Climate, (with the exception of the Lemhi Range) including in the Beaverheads in pp. 80-125, In Halofsky, J. E., the area of known hoary marmot populations (USFS 2018a and USFS Peterson, D. L., Ho, J. J., Little, N. J., 2018b). However, losses would be greater than projected because current and Joyce, L. A., editors. Climate modeling provides an overestimate of precipitation at high elevations. This Change Vulnerability and Adaptation is because it uses the Global Climate Model (GCM), which does not account in the Intermountain Region. Gen. for local orographic effects (Luce et al. 2013). Whether this would be Tech. Rep. RMRS-GTR-xxx. U.S. biologically meaningful is not known. Department of Agriculture, Forest Because marmots obtain water during summer from food plants, changes Service, Rocky Mountain Research in water availability that impacts plants could greatly affect marmot growth Station, Fort Collins, CO. and survival (Armitage 2013). Alpine systems are dependent on snowfields Luce, C. H., Abatzoglou, J. T., Holden, and gradual snowmelt to maintain moisture for vegetation and thus Z. A., 2013, The Missing Mountain warmer temperatures, increased drought, and changes in the depth and Water: Slower Westerlies Decrease persistence of snowpack is projected to greatly affect this habitat in the Intermountain Region (Halofsky et al. 2018; IDFG 2017). Summer Orographic Enhancement in the precipitation is also very important for subalpine forb communities and the Pacific Northwest USA, Science, 342,

Species (Scientific and Common Name): Marmota caligata (Hoary marmot)

RCP8.5 model projects a 20% decrease in summer precipitation for the 1360-1364, DOI: SCNF. However, cooler temperature at higher elevation may moderate 10.1126/science.1242335. effects to alpine forages (Muir et al. 2018). Also, subalpine forb communities may have potential to migrate higher in elevation as a Muir, M., Luce, C. H., Gurrieri, J. T., response to changing conditions, but this may be limited by Matyjasik, M., Bruggink, J. L., Weems, underdeveloped at higher altitudes. In addition, marmots have been S. L., Hurja, J. C., Marr, D. B., Leahy, S. observed moving up to 2 miles to suitable foraging as a response to D. 2018. Chapter 4: Effects of reductions in local forage availability due to extreme weather thus Climate Change on Hydrology, Soil, demonstrating at least short-term flexibility (Armitage 2013). and Water Resources, pp. 126-198, In Halofsky, J. E., Peterson, D. L., Ho, J. Although recent warming has caused an upslope shift in the lower J., Little, N. J., and Joyce, L. A., elevation boundary of yellow-bellied marmots, hoary marmots have little editors. Climate Change Vulnerability opportunity to move farther upslope with warming conditions because and Adaptation in the Intermountain they already occur at extremely high elevations (Armitage 2013). In Region. Gen. Tech. Rep. RMRS-GTR- addition, increased aridity and tree encroachment may isolate marmots, xxx. U.S. Department of Agriculture, which would likely lead to of some populations due to stochastic population decline (Armitage 2013; Griffin et al. 2009). Forest Service, Rocky Mountain Research Station, Fort Collins, CO. Thus, losses of habitat will occur due to climate warming in the form of Riahi, K., S. Roa, V. Krey, C. Cho, V. reduced snowpack for and reductions in foraging habitat and Chirkov, G. Fischer, G. Kindermann, may depart from the natural range of variation (Rank A). However, the N. Nakicenovic, and P. Rafaj. 2011. extent this will occur is unknown due to uncertainty in future CO2 RCP 8.5 – A scenario of comparatively concentrations; the broad scale of precipitation modeling, which does not high greenhouse gas emissions. take into account orographic effects; as well as lack of information on snow Climate change 109:33-57. depths required to insulate dens from extreme cold and for protection doi:10.1007/s10584-011-0149-y. from predators. Thus, whether this will be biologically meaningful is unknown. Sandford, T., P.C. Frumhoff, A. Luers, and J. Gulledge. 2014. The climate Confidence in Rank: High, Medium, or Low policy narrative for a dangerously

Species (Scientific and Common Name): Marmota caligata (Hoary marmot)

warming world. Nature Climate Change 4:164-166.

USFS (U.S. Forest Service). 2018a. Salmon-Challis National Forest: Future April 1 SWE, RCP8.5 2080s. National Forest Climate Change Maps: Your Guide to the Future. Internet website: https://www.fs.fed.us/rm/boise/AW AE/projects/national-forest-climate- change-maps.html. Access 1/25/2018.

USFS (U.S. Forest Service). 2018b. Salmon-Challis National Forest: Historical April 1 SWE, 1975-2005. National Forest Climate Change Maps: Your Guide to the Future. Internet website: https://www.fs.fed.us/rm/boise/AW AE/projects/national-forest-climate- change-maps.html. Access 1/25/2018

USFS (U.S. Forest Service). 2018c. Salmon-Challis National Forest: Change in Annual Average Temperature, historical to 2080s RCP8.5. National Forest Climate Change Maps: Your Guide to the

Species (Scientific and Common Name): Marmota caligata (Hoary marmot)

Future. Internet website: https://www.fs.fed.us/rm/boise/AW AE/projects/national-forest-climate- change-maps.html. Access 1/25/2018.

8 C Hoary marmots live in colonies and form relatively complex social groups Armitage, K. B. 2013. Climate change Life History and (Patil 2010). Excavated are used as shelter from predators and and the conservation of marmots. Demographics weather during all seasons, and as hibernation and communal areas Natural Science. 5 (5A): 36–43. throughout the winter. In general, marmots benefit from deep snow in the winter for insulation and protection from predators, but benefit if the snow Braun, J.K., T.S. Eaton, Jr., and M.A. does not persist into spring. When snow cover is heavy, mortality is low for Mares. 2011. Marmota caligata (Rodentia: Sciuridae). Mammalian all age groups; when snow cover is low, mortality is high for hibernating Species. 43(884):155–171. young (Braun et al. 2011). Therefore, decreasing snow cover due to climate change may increase winter mortality. But early snowmelt may favor Gunderman, D. 2009. Marmota reproduction, although this is dependent on quality forages (Armitage caligata. Diversity Web. 2013) and was found to not benefit survival of hoary marmots in a Yukon Internet website: Territory study (Patil et al. 2013). In addition, reproductive responses to http://animaldiversity.org/accounts/ early snowmelt have been found to vary by species with yellow-bellied Marmota_caligata/. Accessed on September 13, 2017. marmot exhibiting a positive response (Ozgul et al. 2010) and alpine marmots (Marmota marmota) negative (Tafani et al 2013). This may be IDFG (Idaho Department of Fish and attributed to differences in winter snowpack between the study sites and Game). 2017b. Idaho State Wildlife species metabolic rates. With regard to the alpine marmot, increased Action Plan, 2015. Boise, ID. depletion of reserves in pregnant females was attributed to decreased winter insulation in the form of snowpack and relatively inefficient Kyle, C.J., et al. 2007. Social structure metabolic rate and resulted in smaller litter size. and facultative mating systems of hoary marmots (Marmota caligata). Molecular Ecology 16:1245-1256.

Species (Scientific and Common Name): Marmota caligata (Hoary marmot)

In addition, climate change may increase the intensity of storms (Trenberth et al. 2003). If a consistent pattern of late spring storms emerges this could Ozgul, A. D.Z. Childs, M.K. Oli, K.B. especially impacts marmot distribution, survival, and reproduction Armitage, D.T. Blumstein, L.E. Olson, (Armitage 2013). In addition, marmots exhibit considerable plasticity in the S. Tuljapurkar, and T. Coulson. 2010. timing of emergent into and immergence from hibernation, suggesting that Coupled dynamics of body mass and they are highly adaptable to changes in seasonal shifts in snowmelt population growth in response to environmental change. Nature patterns (Armitage 2013). 466:482-485. Hoary marmots are relatively long-lived at approximately 9 years. Survival Patil, V.P. 2010. The interactive is highly variable and can be influenced by weather (Patil 2010). Juvenile effects of climate, social structure, survival in the Yukon Territory ranged from 40% to 95% over 5 years and and life history on the population was primarily influenced by winter climate (survival was lower during dynamics of hoary marmots winters with shallow snowpack) and secondarily by social group size (larger (Marmota caligata). MS thesis, group size promoted group ) (Patil 2010). Winter survival University of Alberta, Edmonton, of adults was influenced by the current season’s climate as well as the Canada. previous with the previous being more influential (Patil et al. 2013). Tafani, M., A. Cohas, C. Bonenfant, J. Breeding females have greater winter mortality rates (68%) than Gaillard, and D. Allaine. 2013. nonbreeding females (Braun et al. 2011). Decreasing litter size of marmots Colonies may be monogamous or polygynous, and social systems may over time: a life history response to change between years due to resource availability, habitat quality, or male climate change. Ecology 94(3):580- 586. fitness (Kyle 2007). Early snow melt or a low snowpack may indirectly affect individual fitness by allowing females to mate with more than one male as is the case when heavy snowpack restricts movements between family groups (Armitage 2013). Reproduction is limited by the ability for females to regain fat stores and the hoary marmot typically skips one or more years between successive reproductions (Armitage 2013). Biennial breeding is a reproductive strategy

Species (Scientific and Common Name): Marmota caligata (Hoary marmot)

often used by species that live in harsh, unproductive environments and may be a consequence of environmental limitations. However, due to the stochastic nature of such environments, this strategy may be maladaptive, because some may not live long enough to reproduce in future years (Patil 2010). Reproductive activity begins immediately after emergence, and the relative reproductive effort is low (Braun et al. 2011). Individuals reach reproductive maturity at 3 years of age. The gestation period is ~30 days, and the average litter size is 2–4 (MNHP and MFWP 2017). Although their large body size allows them to store fat and hibernate, it increases their vulnerability to heat stress (Armitage 2013). Their activity is highly restricted by high temperatures and solar radiation during the summer. Thus, future increased summer temperatures (see Criterion 7), which will be greater at higher elevations, is of concern (Halofsky et al. 2018; USFS 2018). However, marmots burrowing behavior to escape extreme temperatures may buffer the species to impacts of climate warming. In addition, evolutionary adaptation to environmental change has been documented in local populations of yellow-bellied marmot (Armitage 2013). Climate change impacts to marmots may be local rather than widespread as evidenced by loss of local populations after successive years of extreme weather. The degree of isolation between populations was important in their recovery as was the age structure of the surviving populations (Armitage 2013).

Species (Scientific and Common Name): Marmota caligata (Hoary marmot)

Thus, the hoary marmot is a moderately long-lived with a low reproduction rate. Some evidence suggests marmots as a genera have some adaptive capacity to environmental change. The specie’s is physiologically sensitive to higher temperatures, but its burrowing behavior may buffer it from a warming climate, but may suffer higher mortality rates of all ages in areas of lower snowpack. Reproduction may be enhances by a longer growing season due to earlier snowmelt, although genetic fitness may suffer and may be offset my winter mortality. The balance of this information suggests the hoary marmot may be moderately resilient to environmental change (Rank B). Confidence is low given the complexity resulting from the number of factors at play. Confidence in Rank: High, Medium, or Low Summary and recommendations: Date: 2/8/17 Hoary marmots are alpine specialists that are broadly distributed over alpine habitats of . Although they are apparently secure on a global level, there is moderate statewide concern for the species due to habitat threats and data deficiency. No surveys for hoary marmot have been conducted on the Salmon-Challis to determine populations and trends, but 25 individuals have been observed by IDFG staff between 2011 and 2016 within the Beaverhead Mountains. Given their occurrence in nearby mountain ranges off the Forest, it is suspected that additional populations exist on the Forest, but that they are uncommon. Alpine habitat is limited on the Forest, but is well represented and is likely relatively un-impacted across the Forest. Subalpine meadows for foraging are suffering some encroachment of woody plants into meadow habitat, but the extent is not known. Hoary marmots are vulnerable to loss of snowpack, which provides insulation and protection from predators in winter. Based on current models, snowpack extent across the Forest may not decrease over the next 60 years, but depth and persistence will decrease extensively. In addition, these projections are conservative estimates of snowpack loss because they overestimate precipitation, but we do not know by how much. Lower snowpack depths could have consequences for survivorship of all age groups, although juvenile are more heavily impacted. Whether

Species (Scientific and Common Name): Marmota caligata (Hoary marmot) losses in snowpack depth will be biologically meaningful on the Forest is not known. Snowpack of 8 inches or greater likely provide the best insulation from winter temperatures, but this will vary by water content. Using current models snowpack depth of 8 inches or greater on April 1 is projected to remain fairly extensive throughout the Forest including in areas of known hoary marmot populations. However, current models overestimate future precipitation adding uncertainty to our understanding of future threats. Early snow melt under climate warming will provide a longer growing season and this could potentially benefit hoary marmot reproduction, but projected decreased availability of water and increased temperatures will be detrimental to forages. There is some evidence the hoary marmot is capable of moving at least moderate distances to more suitable forage sites, but this will increase exposure to predators and energy expenditure. In addition, marmots show some adaptive capacity to their local environment, but this may be limited if the population is small especially given their slow reproduction rate. Future warmer temperatures could be a detriment to hoary marmots because they are physiologically adapted to cool temperatures. However, it has been postulated that their burrowing habits may buffer their vulnerability. In addition, they may benefit from warmer winter temperatures if snowpack is adequate. Hoary marmots are relatively long lived with low reproductive rates, a strategy thought to be adapted to harsh environments and this may further buffer the species from long-term impacts of climate warming. Thus, climate warming is a potential threat to hoary marmots, but their potential responses are complex and understudied. The species, while sensitive to warmer temperatures shows some potential to adapt. Although future losses of snowpack depth are certain, the amount is not nor is whether losses will be biologically meaningful. Thus, there is insufficient evidence to indicate a substantial concern for the capability of the hoary marmot to persist over the long-term on the SCNF. Evaluator(s): Mary Friberg and Lindsay Chipman