SPECIES: Scientific [common] Ascaphus montanus [Rocky Mountain tailed frog] Forest: Salmon–Challis National Forest Forest Reviewer: Mary Friberg Date of Review: 4/2/2018 Forest concurrence (or No 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__X_
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 ____X___
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 Number of Ranger District Source of Information Observed Individuals 1996–2016 28 Challis–Yankee Fork Ranger Idaho Fish and Wildlife District Information Systems [January 2017]; USFS Natural Resources Information System Wildlife [April 2017] 1996–2016 87 Middle Fork Ranger District Idaho Fish and Wildlife Information Systems [January 2017]; USFS Natural Resources Information System Wildlife [April 2017] 1982–2007 339 North Fork Ranger District Idaho Fish and Wildlife Information Systems [January 2017]; USFS Natural Resources Information System Wildlife [April 2017] 1999–2012 103 Salmon–Cobalt Ranger District Idaho Fish and Wildlife Information Systems [January 2017]; USFS Natural Resources Information System Wildlife [April 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___
If determination is no, stop assessment
N/A—Occurrences have been documented since 1990. d. Map 1, Rocky Mountain Tailed Frog range in Idaho (IDFG 2018)
IDFG (Idaho Department of Fish and Game). 2018. Rocky Mountain Tailed Frog (Ascaphus montanus). Internet website: https://idfg.idaho.gov/species/taxa/18709. Accessed on January 18, 2018. e. Map 2, Rocky Mountain Tailed Frog range in Montana (MNHP and MFWP 2018)
MNHP and MFWP (Montana Natural Heritage Program and Montana Fish, Wildlife, and Parks). 2017. Montana Field Guides – Rocky Mountain Tailed Frog – Ascaphus montanus. Internet website: http://fieldguide.mt.gov/speciesDetail.aspx?elcode=AAABA01020. Accessed on January 18, 2018. f. Map 3, Rocky Mountain Tailed Frog occurrences on the Salmon–Challis National Forest (Idaho Fish and Wildlife Information Systems [January 2017]; USFS Natural Resources Information System Wildlife [April 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 (all at species level except NatureServe Global Rank) NatureServe G4—Apparently Secure (Uncommon but not rare; some cause for long-term concern due to declines or other factors) Global Rank NatureServe S3—Vulnerable in the state of Idaho (Species is at moderate risk of extinction or elimination due to restricted range, few State Rank populations or occurrences, steep declines, severe threats, or other factors) Idaho State Protected Nongame List Status Not listed as a Species of Greatest Conservation Need in Idaho
USDA Forest Region 4—Not listed Service Region 1—Not listed
USDI FWS Not listed Other Not BLM—Idaho Special Status Animal Species Type 2 (Rangewide/Globally Imperiled Species)—These are species that are experiencing significant declines throughout their range with a high likelihood of being listed in the foreseeable future due to their rarity and/or significant endangerment factors (BLM 2015). BLM (United States Department of the Interior, Bureau of Land Management). 2015. Idaho BLM Special Status Species List Update. Instruction Memorandum ID-IM-2015-009. Internet website: https://www.blm.gov/policy/id-im-2015-009. Accessed on January 18, 2018.
Table 3. Status summary based on best available scientific information.
Species (Scientific and Common Name): Ascaphus montanus (Rocky Mountain tailed frog)
Criteria Rank Rationale Literature Citations 1 B1 The Rocky Mountain tailed frog was previously recognized as a Nielson, M., K. Lohman, and J. Distribution on subspecies of the coastal tailed frog (Ascaphus truei). Based on Sullivan. 2001. Phylogeography of Salmon–Challis mitochondrial divergence as well as allozyme and morphology the tailed frog (Ascaphus truei): National Forest differences, inland tailed frog populations became recognized as a implications for the biogeography distinct species, A. montanus, in 2001 (Nielson et al. 2001). In this of the Pacific Northwest. Evolution assessment, any records of observations made in Idaho, but documented 55:147-160. as A. truei, are interpreted as A. montanus (Table 1).
Rocky Mountain tailed frogs are known to occur on four ranger districts on the Forest, including the Middle Fork, North Fork, Salmon–Cobalt, and Challis–Yankee Fork Ranger Districts (Table 1). In addition, an egg mass was identified by IDFG in Hood Gulch on the Leadore Ranger District in May of 2013 (Beth Waterbury pers. commun.). Thus, Occurrence information (including Map 3) suggest that habitat primarily exists as patches, while the species’ specific habitat requirements (see Criterion 6) and limited dispersal capability (Criterion 3) indicate that some habitat may be isolated to the degree that species interactions are limited by movement between patches (Rank B1).
Confidence in Rank: High, Medium, or Low 2 B Rocky Mountain tailed frogs are endemic to the Intermountain British Columbia Ministry of Distribution in northwest of the United States and Canada. The species’ core range Environment. 2014. Recovery plan surrounding extends from the Flathead River drainage in southeastern British for the Rocky Mountain Tailed Frog geographic area Columbia (BC) through western Montana and northern Idaho. Isolated (Ascaphus montanus) in British populations occur in the Yahk River (known as the Yaak River in the US) Columbia. Prepared for the B.C. drainage of southern BC and northwest Montana, western Idaho, Ministry of Environment, Victoria,
Species (Scientific and Common Name): Ascaphus montanus (Rocky Mountain tailed frog)
Criteria Rank Rationale Literature Citations southeastern Washington, and northeastern Oregon (BC Ministry of BC. 37 pp. Environment 2014). Populations have been observed at elevations of at least 7,000 ft in the Wallowa Mountains in northeastern Oregon (Leonard NatureServe. 2018. NatureServe et al. 1993 in NatureServe 2018) to as low as 1,804 ft or less in British Explorer: An online encyclopedia of Columbia (NatureServe 2018). life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Because the species is restricted to a relatively narrow region of the Internet website: Northwest, it has a limited distribution outside the Forest (Rank B). http://explorer.natureserve.org. Accessed on January 18, 2018.
Confidence in Rank: High, Medium, or Low 3 B Dispersal movements of Rocky Mountain tailed frogs are poorly Adams, S. B., and C. A. Frissell. Dispersal understood, but movement is thought to decrease with age. Tadpoles 2001. Thermal habitat use and Capability drift downstream with water currents, and thus can move considerable evidence of seasonal migration by distances along streams (BC Ministry of Environment 2014)—coastal Rocky Mountain tailed frogs, tailed frog tadpoles have been observed to drift downstream up to 213 ft Ascaphus montanus, in Montana. (Jenkins and Ormerod 1996, Wahbe 1996 in COSEWIC 2013). Newly Canadian Field-Naturalist 115:251- metamorphosed froglets typically are sedentary, but juveniles 4–7 years 256. old exhibit a greater level of movement relative to sexually mature frogs (Dupuis 2000 in COSEWIC 2013). Reproductively mature adults in British Columbia Ministry of Montana were documented to move less than 131 ft each year Environment. 2014. Recovery plan (Daugherty and Sheldon 1982a). A sedentary lifestyle may be for the Rocky Mountain Tailed Frog advantageous for securing food, mates, and shelter in an otherwise dry, (Ascaphus montanus) in British inhospitable environment. Columbia. Prepared for the B.C. Ministry of Environment, Victoria, However, movement patterns may depend on local, seasonally changing BC. 37 pp. habitat suitability. In Montana, frogs moved estimated distances of several hundred yards to avoid seasonally high water temperatures COSEWIC (Committee on the Status (Adams and Frissell 2001). Adults are more active nocturnally under of Endangered Wildlife in Canada). suitable ambient air temperature and humidity conditions (Daugherty 2013. COSEWIC assessment and
Species (Scientific and Common Name): Ascaphus montanus (Rocky Mountain tailed frog)
Criteria Rank Rationale Literature Citations and Sheldon 1982a). Individuals are more likely to move along stream status report on the Rocky corridors rather than overland, but overland movements between Mountain Tailed Frog Ascaphus streams are highly likely to occur (COSEWIC 2013). However, dry climatic montanus in Canada. Committee conditions surrounding areas of suitable habitat can isolate on the Status of Endangered subpopulations (Dupuis 2004). This is likely why this species does not Wildlife in Canada. Ottawa. occur at drier lower elevation habitats on the Salmon–Challis National Forest. Daugherty, C.H. and A.L. Sheldon. 1982a. Age-specific movement This information suggests that Rocky Mountain tailed frogs can only patterns of the frog Ascaphus truei. disperse over suitable habitat (Rank B). Herpetologica 38:468-474.
Dupuis, L. 2004. Rocky Mountain tailed frog (Ascaphus montanus). Confidence in Rank: High, Medium, or Low Accounts and Measures for Managing Identified Wildlife – Accounts V. 2004. 4 C The Rocky Mountain tailed frog’s total population size is unknown but Dupuis, L. 2004. Rocky Mountain Abundance on the likely is at least several thousand and may exceed 10,000 (NatureServe tailed frog (Ascaphus montanus). Salmon–Challis 2018). Despite its limited abundance in Canada, the species is still Accounts and Measures for National Forest relatively common in Idaho and Montana (NatureServe 2018) and may Managing Identified Wildlife – be locally common on suitable habitat (Jones 2006). There is high, natural Accounts V. 2004. variability in tailed frog abundance within and among streams, at least in part due to habitat characteristics and natural disturbance regimes NatureServe. 2018. NatureServe (floods, sediment pulses, drought) (Dupuis 2004; Jones 2006). Explorer: An online encyclopedia of life [web application]. Version 7.1. No abundance estimates are available for the Forest, but based on NatureServe, Arlington, Virginia. occurrence data (Table 1), the Rocky Mountain tailed frog could be Internet website: locally common on suitable habitat on the Forest (Rank C); however, http://explorer.natureserve.org. confidence is low due to lack of surveys for this species on the Forest. Accessed on January 18, 2018.
Species (Scientific and Common Name): Ascaphus montanus (Rocky Mountain tailed frog)
Criteria Rank Rationale Literature Citations Confidence in Rank: High, Medium, or Low Jones, J. L., C. R. Peterson, and C. V. Baxter. 2006. Factors Influencing Rocky Mountain Tailed Frog (Ascaphus montanus) Distribution and Abundance. Progress Report for Summer 2005: Montana Fish, Wildlife, and Parks and Potlatch Corporation. February 2006. 5 D Over the short-term, range-wide Rocky Mountain tailed frog populations Friggens, M.M., M.I. Williams, K.E. Population Trend are estimated to be declining by <30% to relatively stable; the long-term Bagne, T.T. Wixom, and S.A. on the Salmon– trend is estimated as declining by <50% to relatively stable (NatureServe Cushman. 2018. Chapter 9: Effects Challis National 2018). These declines may mainly reflect large decreases elsewhere in of climatic change on terrestrial Forest the species range, as it is thought to still be relatively common in Idaho animals. In Halofsky, J.E., D.L. and Montana (NatureServe 2018). However, few population data are Peterson, J.J. Ho, N.L. Little, L.A. available (Friggens et al. 2018; NatureServe 2018). No population trend Joyce, editors. 2018. Climate estimates are available for the Forest, and there is therefore insufficient change vulnerability and information to assess this Criterion (Rank D). Confidence is low due to adaptation in the Intermountain the lack of population trend data for the Forest. Region. Gen. Tech. Rep. RMRS-GTR- xxx. Fort Collins, CO: US Confidence in Rank: High, Medium, or Low Department of Agriculture, Forest Service, Rocky Mountain Research Station. Xxx p.
NatureServe. 2018. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Internet website: http://explorer.natureserve.org.
Species (Scientific and Common Name): Ascaphus montanus (Rocky Mountain tailed frog)
Criteria Rank Rationale Literature Citations Accessed on January 18, 2018.
6 A/B Mating, egg-laying, and larval development occur in clear, cold, swift- British Columbia Ministry of Habitat Trend on moving, mid-elevation (between 5,500 and 8,500 feet) streams; adults Environment. 2014. Recovery plan the Salmon–Challis often use cool, moist riparian zones/forests to forage and may for the Rocky Mountain Tailed Frog National Forest overwinter on land (COSEWIC 2013; Friggens et al. 2018). Suitable (Ascaphus montanus) in British riverine habitats are characterized by cascade and step-pool channel Columbia. Prepared for the B.C. morphologies within small water basins (30–9,538 acres), which provide Ministry of Environment, Victoria, bank stability and pore-space refugia (Dupuis and Friele 2006). Streams BC. 37 pp. flow through young, mature, and old forests with structurally complex riparian zones, which help maintain high humidity and low temperatures COSEWIC (Committee on the Status (Dupuis 2004). Rocky Mountain tailed frogs are typically associated with of Endangered Wildlife in Canada). streambeds largely composed of smooth rocks, cobbles and boulders; 2013. COSEWIC assessment and finer sediments do not provide tadpoles with refuge sites against floods, status report on the Rocky debris, predators, or elevated temperatures (Dupuis 2004). Mountain Tailed Frog Ascaphus montanus in Canada. Committee Rocky Mountain tailed frogs are sensitive to temperature and on the Status of Endangered sedimentation, making water quality an important indicator of habitat Wildlife in Canada. Ottawa. suitability. Sediment inputs to streams degrade habitat by increasing bedload movement and reducing interstitial refugia and foraging areas Dupuis, L. 2004. Rocky Mountain (Dupuis 2004). Based on indicators for water quality in surface water tailed frog (Ascaphus montanus). systems, the water quality of almost all land type associations (LTAs) Accounts and Measures for where the Rocky Mountain tailed frog is known to occur is within the Managing Identified Wildlife – natural range of variation (NRV) (Figure 7 in USFS 2017a). However, Accounts V. 2004. water temperature is significantly altered in more than 15% of watersheds (Appendix D in USFS 2017a). Dupuis, L., and P. Friele. 2006 The distribution of the Rocky Mountain At northern latitudes it takes up to four years for tadpoles to tailed frog (Ascaphus montanus) in
Species (Scientific and Common Name): Ascaphus montanus (Rocky Mountain tailed frog)
Criteria Rank Rationale Literature Citations metamorphose and begin lotic and terrestrial activity, and thus larval life relation to the fluvial system: stages are particularly vulnerable to extreme water fluctuations that implications for management and cause channel disturbance (Dupuis and Friele 2006). Conifer and upland conservation. Ecological Research encroachment as well as deviations in winter temperature and 21:489-502. precipitation indicate flow regimes of surface water systems are largely trending towards NRV (Figure 5 in USFS 2017a); however, some LTAs Friggens, M.M., M.I. Williams, K.E. outside NRV are near tailed areas where frog occurrences have been Bagne, T.T. Wixom, and S.A. documented (Map 3; USFS 2017a). Primary stressors include roads in the Cushman. 2018. Chapter 9: Effects floodplain, diversions, mining, recreation sites in the floodplain, grazing, of climatic change on terrestrial and recent changes in climate (USFS 2017a). animals. In Halofsky, J.E., D.L. Peterson, J.J. Ho, N.L. Little, L.A. Riparian vegetation provides cover, foraging habitat, and bank Joyce, editors. 2018. Climate stabilization. There are 45,732 acres (1% of the Forest) of riparian change vulnerability and vegetation types on the Forest as mapped by LANDFIRE existing adaptation in the Intermountain vegetation type (EVT) data. The percent cover of these areas varies from Region. Gen. Tech. Rep. RMRS-GTR- 0.1% to 8% with a mean of 1% (USFS 2017a). Despite past declines, the xxx. Fort Collins, CO: US condition and composition of riparian ecosystems on the Forest are Department of Agriculture, Forest within or trending towards the NRV at the majority of LTAs based on the Service, Rocky Mountain Research following indicators: (1) conifer encroachment (2) upland encroachment Station. Xxx p. (3) introduced vegetation (4) tree mortality or defoliation, (5) percent native cover, (6) percent alien cover, (7) percent greenline cover, and (8) Hossack, B. R., P. S. Corn, and D. B. percent effective ground cover (USFS 2017a). Areas where riparian Fagre. 2006. Divergent patterns of ecosystems are outside the NRV include habitat along the Middle Fork, abundance and age-class structure North Fork, and mainstem Salmon rivers; some tailed frog occurrences of headwater stream tadpoles in have been documented in tributaries of these rivers, but this species burned and unburned watersheds. generally occurs at higher elevations (Map 3). Changes to riparian Canadian Journal of Zoology. composition and condition on the Forest are mainly from expansion of 84:1482–1488. shrubland and conifer species into riparian areas, which has been further exacerbated by fire suppression, upland encroachment (possibly due to IUCN (International Union for roads, diversions, and increased temperatures and drought) and Conservation of Nature) SSC
Species (Scientific and Common Name): Ascaphus montanus (Rocky Mountain tailed frog)
Criteria Rank Rationale Literature Citations nonnative plant species (USFS 2017a). Amphibian Specialist Group. 2015. Ascaphus montanus. The IUCN Red In British Columbia, the species’ range corresponds to the Engelmann List of Threatened Species 2015. Spruce-Subalpine Fir biogeoclimatic zone (COSEWIC 2013); this cover Internet website: type represents about 360,000 acres or 8% of the Forest (USFS 2017b). http://www.iucnredlist.org/details/ Rocky Mountain tailed frogs also are associated with streams in old 54413/0. Accessed on February 8, growth and mature structural stages, where required microclimatic and 2018. microhabitat conditions are more common (Dupuis 2004). Based on the Hamilton criteria for tree size, density, and age, there are an estimated NatureServe. 2018. NatureServe 20,872–50,206 acres of old-growth in Engelmann Spruce and Engelmann Explorer: An online encyclopedia of Spruce/Subalpine Fir forest types on the Salmon-Challis National Forest life [web application]. Version 7.1. (10%–23%, 67% confidence) (USFS 2017b). Despite their preference for NatureServe, Arlington, Virginia. old-growth forests and sensitivity to sedimentation caused by logging, Internet website: tailed frogs also occur in many young forests that have been harvested in http://explorer.natureserve.org. the past (IUCN 2015). Sensitivity to timber harvest may depend on Accessed on January 18, 2018. surface geology and harvest practices (Adams and Bury 2002, Welsh and Smith, G., J. Lemly, and K. Schroder. Lind 2002 in IUCN 2015). However, further information is needed to 2017. Fen Mapping for the Salmon- assess the response of this species to timber harvest (IUCN 2015; Challis National Forest. Colorado NatureServe 2018). Natural Heritage Program, Colorado State University, Fort Collins, Fire suppression has altered habitat by promoting conifer and upland Colorado. encroachment into riparian habitats (USFS 2017a). Fire suppression also has increased the frequency and intensity of major wildfires on the USFS (United States Department of Forest in recent decades (USFS 2017b), which degrades riparian habitat Agriculture, Forest Service). 2017a. (USFS 2017a) and is detrimental to the species, as tadpoles in Montana Salmon-Challis National Forest Plan were almost half as abundant in burned that in unburned streams Revision Assessments. Topics 1 and (Hossack et al. 2006). 2 – Terrestrial Ecosystems, Aquatic Ecosystems, Watersheds, Air, Soil, Overall, forested habitat remains broadly available on the Forest, but a Water. September 4, 2017. large percent of key riparian ecosystem characteristics (surface flows)
Species (Scientific and Common Name): Ascaphus montanus (Rocky Mountain tailed frog)
Criteria Rank Rationale Literature Citations have deviated from historic conditions. However, several indicators USFS (United States Department of suggest that habitat characteristics are returning to NRV. Rank A/B was Agriculture, Forest Service). 2017b. chosen to reflect these conditions. Confidence is medium due to spatial Salmon–Challis National Forest variation in habitat conditions. Terrestrial Ecosystem Assessment. Draft. December 5, 2017. Confidence in Rank: High, Medium, or Low
7 A Land-use practices that increase sedimentation or stream temperatures, Behrens, P.N., R.E. Keane, D.L. Vulnerability of and reduce interstitial spaces in substrates or habitat moisture (through Peterson, and J.J. Ho. 2018. Habitats on the loss of stream and terrestrial canopy cover) are thought to seriously Chapter 6: effects of climatic Salmon–Challis degrade stream habitats used by Rocky Mountain tailed frogs (Hayes and variability and change on forest National Forest Quinn 2015 in Halofsky et al. 2018). Erosion of road surfaces, ditches, and vegetation. In Halofsky, J.E., D.L. cutbanks during and following logging is a significant source of sediments Peterson, J.J. Ho, N.L. Little, L.A. in streams. Timber harvest on the Forest has decreased relative to Joyce, editors. 2018. Climate historic levels and is likely not a high threat, particularly as Engelmann change vulnerability and spruce is not a targeted species (USFS 2017b). Livestock grazing and adaptation in the Intermountain roads, however, have negatively impacted surface and groundwater Region. Gen. Tech. Rep. RMRS-GTR- fluctuations, water quality, channel and floodplain dynamics, spring xxx. Fort Collins, CO: US runout channel dynamics, and composition and condition of riparian Department of Agriculture, Forest ecosystems and GDEs on the Forest (USFS 2017a). The high number of Service, Rocky Mountain Research unimproved roads (about 66%, USFS 2017a) may be a chronic source of Station. Xxx p. stream sedimentation. Improper livestock grazing can decrease water quality by increasing erosion and runoff, reduce vegetation and coverage, Halofsky, J., D. Peterson, J. Ho, N. and cause direct mortality of frogs via trampling. Grazing levels on the Little, and L. Joyce. 2018. Climate Forest are believed to be much lower than historic levels, and 78% of 107 Change Vulnerability and monitored pastures in riparian areas met percent forage utilization Adaptation in the Intermountain standards in 2012, indicating that grazing practices are improving, Region. Gen. Tech. Rep. RMRS- probably in response to concerns over impacts to riparian ecosystems GTR20-xxx. Fort Collins, CO: U.S. (USFS 2017a). However, grazing is still a dominant land use on the Forest Department of Agriculture, Forest (USFS 2017c), and this is not expected to change in the future; thus, Service, Rocky Mountain Research
Species (Scientific and Common Name): Ascaphus montanus (Rocky Mountain tailed frog)
Criteria Rank Rationale Literature Citations improper grazing is considered a significant threat. 21 Station. xxx p. Unpublished draft. A legacy of fire suppression on the Forest has increased the frequency and intensity of major wildfires in recent decades (USFS 2017b); these Hossack, B. R., P. S. Corn, and D. B. large, non-typical wildfires lead to very unstable soil and slope conditions Fagre. 2006. Divergent patterns of that may cause chronic sediment release and also may lead to changes in abundance and age-class structure riparian composition (USFS 2017a). Fire suppression activities, such as of headwater stream tadpoles in firebreaks, vehicle access roads, and use of chemical flame retardants, burned and unburned watersheds. are potentially a greater threat than wildfires, as they can cause Canadian Journal of Zoology. extensive erosion and silting of streams or contaminate streams and 84:1482–1488. surrounding forests (COSEWIC 2013). Joyce, L.A. and M. Talbert. 2018. Chapter 3: Historical and projected To project the future climate and impacts to resources in the climate. In Halofsky, J.E., D.L. Intermountain Region including the Salmon-Challis, the Intermountain Peterson, J.J. Ho, N.L. Little, L.A. Adaptation Partnership (IAP) used Representative Concentration Joyce, editors. 2018. Climate Pathway [RCP] 4.5 and 8.5, which capture a moderate and high future change vulnerability and warming, respectively (Halofsky et al. 2018). Although pathways adaptation in the Intermountain predicting lower warming exist, the 4.5 and 8.5 pathways were chosen by Region. Gen. Tech. Rep. RMRS-GTR- the IAP because they are, in comparison, well studied providing a large xxx. Fort Collins, CO: US set of projections that enhance our understanding of the possible range Department of Agriculture, Forest in future climate. Thus, this represents best available science for our Service, Rocky Mountain Research Forest with regard to a warming climate. 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 USFS (United States Department of temperatures are the most certain consequence of increased CO2 in the Agriculture, Forest Service. 2017a. atmosphere. By 2100, median minimum and maximum temperature in Salmon-Challis National Forest Plan the Middle Rockies sub-region, which includes the Salmon-Challis, is Revision Assessments. Topics 1 and projected to rise about 5-6˚F under the moderate warming scenario and 2 – Terrestrial Ecosystems, Aquatic about 10˚F under the high warming scenario. Regardless of scenario, the Ecosystems, Watersheds, Air, Soil,
Species (Scientific and Common Name): Ascaphus montanus (Rocky Mountain tailed frog)
Criteria Rank Rationale Literature Citations greatest departure from historical seasonal minimum temperatures Water. September 4, 2017. occurs in the summer. Annual precipitation projections are highly variable with no discernible trend under moderate warming and a slight USFS (United States Department of increasing trend with high warming (Joyce and Talbert 2018). Agriculture, Forest Service). 2017b. Mid-elevation (between 5,500 and 8,500 feet) riparian and wetland Salmon–Challis National Forest communities such as those occupied by Rocky Mountain tailed frogs in Terrestrial Ecosystem Assessment. the Intermountain Region will be moderately to highly vulnerable to Draft. climate change, while Rocky Mountain tailed frogs are expected to be moderately vulnerable (Halofsky et al. 2018). Because they require cold USFS (United States Department of water, increasing temperatures may decrease habitat suitability, Agriculture, Forest Service). 2017c. particularly warmer areas downstream of headwaters (Isaak et al. 2017 Salmon–Challis National Forest in Halofsky et al. 2018). An increase in the frequency of disturbances such Draft Assessment Report. October as extreme floods or postfire debris flow may threaten the persistence of 2017. some populations, as this species is thought to rebound slowly from disturbances (see Criterion 8) (Hossack et al. 2006; Hossack and Pilliod 2011 in Halofsky et al. 2018). Tailed frog populations may also be negatively affected by more extreme summer droughts or wildfires that open riparian canopies, which can decrease habitat quantity and quality (Hossack et al. 2006; Hossack and Pilliod 2011 in Halofsky et al. 2018). However, mid-elevation riparian and wetland systems typically have high fuel moisture and are not very susceptible to wildland fire and sub-alpine forest will have the capacity to move up in elevation (Halofsky et al. 2018).
In mid-elevation riparian areas, the amount of water available for subsurface storage will likely be reduced as snowpack decreases and runoff seasonality changes. Increasing temperatures will increase competition from invasive and riparian species from lower elevations, while reduced water tables will increase competition from adjacent upland species (Halofsky et al. 2018). Thus, the species composition of
Species (Scientific and Common Name): Ascaphus montanus (Rocky Mountain tailed frog)
Criteria Rank Rationale Literature Citations these riparian areas could change considerably in a changing climate and could reduce habitat quantity and quality for tailed frogs. Areas impacted by improper grazing, roads, and nonnative species will be less able to adapt to climate changes (Halofsky et al. 2018). However, these projected impacts may be lower in central Idaho relative to the rest of the Intermountain Region due to greater retention of snowpack, potential increases in precipitation, and a relatively cooler future climate (Halofsky et al. 2018). The RCP 8.5 climate model predicts a slight increase in precipitation in the Middle Rockies through the remainder of the 21st century, suggesting that decreasing snowpack and more extreme summer droughts may be less serious threats on the Forest relative to the rest of the Intermountain Region (Halofsky et al. 2018).
Overall, sedimentation from unimproved roads, improper livestock grazing, and fire suppression activities may impact Rocky Mountain tailed frogs with effects departing from the NRV (Rank A); climate change will also decrease habitat, but the extent is uncertain. Confidence is low due to uncertainty in climate change predictions, especially with respect to precipitation.
Confidence in Rank: High, Medium, or Low 8 A Tailed frogs have low reproductive rates compared to other frogs Blaustein, A. R. 1995. The Biology Life History and (COSEWIC 2013). Rocky Mountain tailed frogs develop slowly, reaching of Amphibians and Reptiles in Old- Demographics sexual maturity at 7–8 years (Daugherty and Sheldon 1982b). Fertilization growth Forests in the Pacific occurs internally, and females lay 50 – 85 eggs every other year, which Northwest. Corvallis, Or. U.S. Dept. take 4–6 weeks to hatch (Metter 1964; Nussbaum et al. 1983 in COSEWIC of Agriculture, Forest Service, 2013). Tadpoles typically metamorphose after about 3 years, although Pacific Northwest Research Station. the length of the larval period depends on water temperature and food availability (Daugherty and Sheldon 1982a). Tadpoles have a modified British Columbia Ministry of mouth that enables them to feed on periphyton and also acts as a sucker Environment. 2014. Recovery plan
Species (Scientific and Common Name): Ascaphus montanus (Rocky Mountain tailed frog)
Criteria Rank Rationale Literature Citations to provide stability against currents (Blaustein 1995). Adults eat a variety for the Rocky Mountain Tailed Frog of invertebrates and insects found near creeks (NatureServe 2018). (Ascaphus montanus) in British Columbia. Prepared for the B.C. Survival rates of adults are unknown, but adults may live to the age of 14 Ministry of Environment, Victoria, (Daugherty and Sheldon 1982a). Predators include cutthroat trout, garter BC. 37 pp. snakes, and western toad (COSEWIC 2013). Many amphibian populations around the world are threatened by epizootic chytridiomycosis disease Daugherty, C.H., and A.L. Sheldon. caused by the fungus Batrachochytrium dendrobatidis, but there is 1982b. Age determination, growth, currently no evidence of significant infection or disease among Rocky and life history of a Montana Mountain tailed frogs (COSEWIC 2013). population of the tailed frog (Ascaphus truei). Herpetologica Required temperatures for egg survival are between 5°C and 18.5°C 38:461-468. (Brown 1975 in British Columbia Ministry of Environment 2014); optimal temperatures for tadpoles are between 9°C and 16°C (Dupuis 2000 in Dupuis, L. 2004. Rocky Mountain British Columbia Ministry of Environment 2014); and lethal maximum tailed frog (Ascaphus montanus). water temperatures for adults range from 22°C to 24.1°C (Metter 1966, Accounts and Measures for Claussen 1973 in British Columbia Ministry of Environment 2014). Managing Identified Wildlife – Accounts V. 2004. Despite apparent longevity, the Rocky Mountain tailed frog has a long larval stage and low reproductive rate. Combined with apparently low dispersal abilities and specific habitat needs (Dupuis 2004; NatureServe 2018), this species may have a limited ability to recover from disturbance (Rank A). Confidence is medium due to lack of information on survival rates.
Confidence in Rank: High, Medium, or Low
Species (Scientific and Common Name): Ascaphus montanus (Rocky Mountain tailed frog)
Criteria Rank Rationale Literature Citations Summary and recommendations: Date: 1/29/2018
Conservation assessments indicate only moderate concern for the Rocky Mountain tailed frog in Idaho, where it is ranked as S3 (Vulnerable). However, the Idaho Department of Fish and Game does not consider it a species of greatest conservation need in their recent State Wildlife Action Plan and it is considered apparently (G4) secure range-wide. Population abundance and trends are not know on the Salmon-Challis. They may be locally common on suitable habitat. Tailed frogs occupy mountain streams and surrounding forested riparian zones and moist areas. Main stressors to these habitats on the Forest include sedimentation from unimproved roads, improper livestock grazing, fire suppression, and changes in climate. Forested and riparian habitat is broadly available on the Forest, although riparian habitat quality (e.g., surface flows) has declined from historic conditions but is improving across most of the Forest. Rocky Mountain tailed frog populations may be vulnerable to disturbance due to their long larval stage, low reproductive rate, low dispersal ability, and specific habitat needs. However, they are only moderately vulnerable to changes in climate and the extent climate will change is uncertain. Thus, in the absence of population information for the Forest, we conclude stressor may be impacting populations, but there is low concern for this species in Idaho and range-wide. Therefore, information is lacking to indicate a substantial concern for the capability of the Rocky Mountain tailed frog to persist over the long-term on the Salmon-Challis. It is not recommended as a species of conservation concern.
Evaluator(s): Lindsay Chipman