QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson SIERRA NEVADA YELLOW‐LEGGED FROG MONITORING HFQLG PILOT PROJECT AREA PLUMAS AND TAHOE NATIONAL FORESTS FEBRUARY, 2013 1 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson INTRODUCTION Included in the Herger‐Feinstein Quincy Library Group (HFQLG) Pilot Project Act is a Monitoring Plan intended to assess the effects of implementation of land management (timber harvest, watershed restoration, fuels reduction) activities on the Lassen, Plumas, and the Sierraville Ranger District of the Tahoe National Forest. One component of this plan is the monitoring of amphibian species within the HFQLG Pilot Project area. Specifically, Question 22 of the HFQLG Monitoring plan states, “Do amphibians persist at currently occupied sites?” Initially, monitoring efforts to answer this question began in the year 2000 and were carried forward every two years through 2008 utilizing a survey method that was based on presence or absence of Forest Sensitive frog species as defined by the Regional Forester in the Region 5 Sensitive Species List. These surveys were located at current and/or historical locations where Cascades frogs (Rana cascadae), foothill yellow‐legged frogs (R. boylii), and Sierra Nevada yellow‐legged frogs (R. sierrae) occurred, although these surveys locations were not necessarily located within HFQLG projects areas and in most cases did not assess impacts of HFQLG activities. Following a meeting with the Pinchot Institute in 2008, it was determined that the monitoring strategy described above was not adequate to assess the potential effects of HFQLG actions on frog populations or their respective habitats. As such, in 2009 it was decided to monitor population abundances of current populations of Forest Sensitive frog species that occupied habitat within or directly adjacent to proposed HFQLG projects that were planned to be implemented within the next two years (2009‐2011). Five locations supporting populations of Sierra Nevada yellow‐legged frogs were identified on the Plumas and Tahoe National Forests that were good candidates for assessing the effects of proposed HFQLG vegetation management actions. Once historically abundant in the Sierra Nevada (Grinnell and Storer, 1924), the Sierra Nevada yellow legged frog has disappeared from 93% of its historical localities (Vredenburg et al. 2007). It is considered warranted for listing under the Endangered Species Act but precluded by higher priority actions at the federal level (USFWS 2003, 2007), warranted for listing as a threatened species at the state level (California Fish and Game Commission 2012), and is a USDA Forest Service sensitive species (USDA Forest Service 1998). The mountain yellow legged frog complex, which includes the Sierra Nevada yellow‐legged frog (see natural history below), has been relatively well‐studied in high alpine lake habitats in the central and southern Sierra (e.g., Bradford 1984, Matthews and Pope 1999, Knapp and Matthews 2000, Knapp et al. 2003, Matthews and Priessler 2010, Vredenburg et al. 2010). Little is known, however, about the ecology of the taxa in the northern part of its range, which includes the 2 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson HFQLG project area, where lakes are less common and the frog occurs predominately in streams. The majority of vegetation management activities and watershed improvement projects developed to meet the intention of HFQLG are often associated with existing road networks and topographic features which result in stream channel environments having the greatest potential for change due to project implementation. To address this knowledge gap, population monitoring of the Sierra Nevada yellow‐
legged was conducted in the HFQLG project area from 2009 to 2011. The objectives of the monitoring were to: 1. Increase our knowledge of the demography and habitat usage of the Sierra Nevada yellow‐
legged frogs in streams in the northern part of its range. 2. If possible, investigate the effects of HFQLG land management actions, including vegetation and fuels treatments, on population abundance and suitable habitats of the Sierra Nevada yellow‐legged frog. We recognized that our ability to address this important question would likely be limited because proposed treatments might not be implemented, sample sizes would be very low, and three years is a short time period for observing effects. However, the results of this monitoring will likely help land managers develop projects that protect and/or enhance potential suitable habitat for Sierra Nevada yellow‐legged frogs through a better understanding of what aquatic and riparian habitats in close proximity to stream channels are utilized by this species. We present results from the three years of monitoring including Sierra Nevada yellow‐legged frog abundance and demography, movement patterns, and habitat usage. We also discuss management implications and recommendations for maintaining and/or enhancing existing Sierra Nevada yellow‐
legged frog habitat and populations. SIERRA NEVADA YELLOW‐LEGGED FROG NATURAL HISTORY Vredenburg et al. (2007) split Rana muscosa into two taxa, Rana sierrae, which is endemic to the northern and central Sierra Nevada, and Rana muscosa, which occurs in the southern Sierra Nevada and southern California. Rana sierrae occurs in the HFQLG project area. Most studies on this taxon were conducted prior to the taxonomic revision so the following description applies to both species. The mountain yellow‐legged frog is highly aquatic and its use of aquatic habitats may differ across its range. Larvae take two to three years to metamorphose and thus require permanent water that does not freeze overwinter to survive (Zweifel 1955, Bradford 1983). The more well‐known habitats used for breeding are deep lakes, at least in the central and southern Sierra (Knapp and Matthews 2000, Knapp 3 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson et al. 2003). However, the taxon also breed in other habitats including streams and wet meadows, particularly in the northern parts of its range. During nonbreeding periods, adults use a larger variety of aquatic habitats for feeding, including more ephemeral sites unsuitable for overwintering or breeding (Pope and Matthews 2001). In alpine areas in the central and southern Sierra, frogs move among lentic habitats including overland travel, but tend to return to the same places to breed and overwinter (Pope and Matthews 2001, Matthews and Priessler 2010). Large populations with hundreds of frogs have been reported for lakes in high alpine areas in the central and southern Sierra (Grinnell and Storer 1924, Bradford 1991, Pope 1999, Vredenburg et al. 2010). However, to our knowledge, no such populations have been reported for streams in the species’ northern range. Biologists report finding the occasional frog while conducting stream surveys but, with a few exceptions, not the densities commonly reported in lake environments. It is not known whether abundances are low in HFQLG project area streams or whether the species ecology differs in this part of the range and populations are more dispersed. METHODS STUDY SITE SELECTION The following criteria were used for selecting study sites for monitoring: 1) Sierra Nevada yellow‐legged frogs were known to occur, and 2) proposed HFQLG management activities were located within or adjacent to suitable or occupied habitats and were planned to be implemented within the next two years. In particular, those projects that included proposed treatments within riparian habitat conservation areas (RHCAs) were given higher priority than those that did not, as these were likely to have the greatest potential for affecting suitable frog habitat. Riparian habitat conservation areas are an HFQLG land base designation with specific standards and guidelines associated with land management activities with the purpose of maintaining hydrologic, geomorphic, and ecologic processes that directly affect streams, stream processes, and aquatic habitats. Furthermore, RHCAs include and preserve valuable terrestrial habitats for native flora and fauna. Five sites were selected based on these criteria (Table 1). As time permitted, additional efforts were made to document reproduction and to survey areas with prior locality data nearby the selected monitoring sites. These areas included a flooded meadow with high beaver activity and sections of five tributaries at Independence Creek, five tributaries, springs, and ponds at South Fork Rock Creek, and the stream below the selected monitoring section and the meadow adjoining private property at Lone Rock Creek. Because of the large number of frogs found at the beaver meadow at Independence Creek, we increased our effort to the full survey protocol in 2010 4 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson and 2011. At Boulder Creek, because no Sierra Nevada yellow‐legged frog were found in the selected monitoring section in 2009, we extended our surveys to the stream reach continuing approximately 1.5 km upstream of Lowe Flat in 2010 and, having found frogs, implemented the full survey protocol along this section in 2011. We also surveyed a tributary west of Boulder Creek and an adjoining meadow. Table 1. Summary of Sierra Nevada yellow‐legged frog habitat and population survey sites. Survey Site Habitat Type HFQLG Project Independence Creek Stream/Meadow/Beaver Outback Project Comments Ponds Potosi Creek (Howland Stream Sugarberry Project South Fork Rock Creek Stream/Meadow Meadow Valley Project Lone Rock Creek Stream/Meadow/Beaver Moonlight Fire Flat) Boulder Creek (Lowe Ponds Recovery Project Stream/Meadow Wildcat Project Dropped from study due to non‐presence of R. sierrae Flat) Initially, one of the goals of this monitoring effort was to compare habitat attributes within suitable and occupied habitat for Sierra Nevada yellow‐legged frogs pre and post HFQLG project implementation. However due various reasons, none of the proposed actions located within or adjacent to this habitat was completed within the three year period (2009‐2011). HFQLG treatments associated with the South Fork Rock Creek monitoring site (Meadow Valley Project) were completed in 2009, prior to the initiation of this monitoring. Therefore, habitat data collected in 2009 within Independence, South Fork Rock Creek, Lone Rock Creek, and Boulder Creek will be used in this report for describing baseline habitat conditions where these populations are located. Potosi Creek (Howland Flat) was initially included in this study, however due to the lack of occupancy of Sierra Nevada yellow‐legged frogs during surveys completed in 2009 and 2010, this study site was dropped from further data collection in 2011 and will not be further evaluated in this document. FIELD METHODS Species Surveys 5 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Field crews conducted surveys for amphibians and reptiles at the primary monitoring sites the third week in August in 2009, 2010, and 2011. Each site was surveyed on four consecutive days for at least 6 hours per day between 0930 and 1730. Additional surveys of varying lengths of time were performed at the additional sites as time permitted. Visual encounter techniques were used as well as dipnetting and binocular scans to locate and identify amphibians and reptiles (Heyer et al. 1994). All aquatic habitats within the vicinity of the primary site were searched including the channel itself, mouths of tributaries, backwaters, and side channels as well as adjacent meadow habitat. The weather generally was clear during all surveys with no precipitation and no or light wind. Average air temperatures (measured at the beginning and end of each day) ranged from 18 oC ‐ 24 oC. For all Sierra Nevada yellow‐legged frogs, sex, length, weight, and coordinates of capture location were recorded. We collected tissue swabs from a subset of amphibians for detection of the presence of the chytrid fungus, Batrachochytrium dendrobatidis (Boyle et al. 2004, Frías‐Alvarez et al. 2008). We employed capture‐mark‐recapture techniques (CMR) to estimate population abundances for adult frogs. All unmarked Sierra Nevada yellow‐legged frogs >40 mm snout‐urostyle length were PIT‐
tagged using AVID MUSICC MicrochipsTM (Heyer et al. 1994, Pope and Matthews 2001) which enabled us to identify individuals and record recaptures. Habitat Surveys To assess existing stream channel and riparian habitat conditions and Sierra Nevada yellow‐legged frog habitat associations within the selected monitoring sites, field crews collected data at two scales. First, in 2009 reach‐scale habitat data was collected within the pre‐determined stretch of stream channel of each study site. Reach scale data collected included channel gradient, habitat unit type (e.g., pool, run, riffle type), bankfull width (m), wetted width (m), greenline width (m), pool water depth (m), residual pool depth (m), percent of pool tail fines, stream shading (% canopy), riparian hardwood age structure, large woody debris (tally and recruitment potential), and bank stability. The California Steelhead Habitat Restoration Manual (CDF&G, 1998) was used to characterize habitat units within the survey site. Second, in 2009, 2010, and 2011 habitat data were collected at the site where individual frogs were encountered during population surveys. Microhabitat data were collected at each frog locality the first time an individual frog was found each day. A second collection of microhabitat data occurred if the same frog was found greater than 4 hours since the last sighting. Data collected described 1) the general habitat including location relative to the stream (e.g., in stream, on shore, backwater), habitat unit type (e.g., pool, run, riffle type), and distance to shore or water (m), 2) stream 6 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson size including water depth (m) and wetted width (m), 3) cover including dominant substrate and percent of cover for different cover types (herbaceous, woody, woody debris, total cover), and 4) shade. Total cover included any type of cover in which a frog could hide such as silt or cobble substrate, vegetation, or woody debris. ANALYSIS Sierra Nevada Yellow‐legged Frog Abundance and Survival Capture‐mark‐recapture data for the Sierra Nevada yellow‐legged frog were analyzed to estimate abundance and survival rate of adults at each monitoring site. Analyses were run separately for each site, and the analysis methods used were determined by the amount of data available. At Independence Creek, S.F. Rock Creek, and Lone Rock Creek, where three years of mark‐
recapture was completed and sample sizes were sufficient, we used Pollock’s robust design to estimate population size and survival (Pollock 1982). The robust design is a two tiered approach that allows for open populations among primary periods (populations gains and losses can occur among years; i.e., recruitment, immigration, mortality, emigration), but assumes population closure (no population gains or losses) among more closely spaced secondary sampling occasions (i.e., four consecutive days within each year). We validated the closure assumption for each site/year by comparing a Pradel model (Pradel 1996) with no immigration (recruitment = 0, closed model) to a model allowing immigration (recruitment unconstrained, open model) (Boulanger et al. 2002). The closed and open models for each meadow and year were compared using likelihood ratio tests. In all cases, the closed model had the most support or there was no difference between the models which means the closure assumption was valid. To reduce the number of models for comparison, we conducted exploratory analysis for each site/year by fitting the data to four Huggins closed population models where the probability of capture was held constant (Mo) or allowed to vary by behavior (Mb), time (Mt), or both (Mtb) (White et al. 1982). For each site, we chose the closed population model that had the most support, based on Akaike weights (wi) using QAICc values, for inclusion in the robust design analysis. We fit the data to 12 models using Pollock’s robust design model where 1) apparent survival (Φ) was held constant or allowed to vary among years, 2) the probability of capture (p) and recapture (c) were modeled with the most supported closed population model and were either held constant or were allowed to vary among years, and 3) temporary emigration (G) was either none (frogs did not skip years), random (frogs presence was random ), or Markovian (the probability of the frog's presence at the aggregation was dependent on its presence the prior year). We used the program, RDSurviv (Kendall and Hines 1999), to test the 7 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson goodness of fit for the most general model for each meadow and to calculate the variance inflation factor, ̂ , based on the Pearson's X2 test ( ̂ =X2/df, Amstrup et al. 2005). Model selection was based on Akaike weights (wi) calculated from QAICc values (Burnham and Anderson 2002). Some models could not be fit to the data or had unreasonable parameter estimates, and were dropped from the final model set. Final estimates were calculated by model averaging of the final model set (Burnham and Anderson 2002). Model fitting and averaging were conducted using the R (R Development Core Team 2009) package, RMARK (Laake 2010). At the Beaver Pond meadow (Independence Creek), where only two years of mark recapture were completed, we analyzed the mark recapture data for the Sierra Nevada yellow‐legged frog using Huggins closed capture models in program MARK (White and Burnham 1999). We fit the data to four models where the probability of capture was held constant (Mo) or allowed to vary by behavior (Mb), time (Mt), or both (Mtb, White et al 1982). Some models could not be fit to the data or had unreasonable parameter estimates, and were dropped from the final model set. Final population and parameter estimates were calculated by model averaging of the final model set (Burnham and Anderson 2002). At Boulder Creek and the additional survey sites, sample sizes were insufficient for mark recapture analysis and we report only the number of unique individuals detected. Because larvae and most subadults could not be marked individually with PIT tags, CMR analysis was not possible for these life stages. To provide a conservative population index that minimizes doubly counting individuals, we report the maximum number of individuals observed in a single day. To examine temporal occupancy patterns among years, we summarized the number of individuals present one, two, and three years of survey and the number of individuals that skipped years. Distance Travelled and Spatial Distribution We investigated the distance travelled by frogs both within each four day CMR period and among years. We combined the June and August surveys at Independence Creek in 2010. We recorded the coordinates for each frog location using a Garmin handheld GPS unit. We then calculated the straight line distance between each pair of consecutive frog locations. Because individuals were captured multiple times during a single year, we selected the last capture date in each year as a representative position to calculate distance moved among years. To investigate the spatial distribution of frogs along each site, we mapped each frog location by life stage for each year and visually examined the patterns. 8 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Habitat The existing suitable habitat at the reach wide scale within the survey site and microhabitat associations of Sierra Nevada yellow‐legged frogs were examined descriptively. For overall frog habitat associations and comparisons by sex, only data for marked adults on the four primary monitoring sites were used. Our methods were less appropriate for the more lentic Beaver Pond meadow. To examine the influence of multiple captures of the same frog, we randomly selected one capture per individual. Because results were similar, our summaries here include data for all captures. We used all data on adults and subadults to compare life stages. Descriptive narratives are provided for tadpole locations since so few were found. There were few differences among monitoring sites so data for all sites were combined. RESULTS STUDY SITE REACH WIDE HABITAT AND HFQLG PROJECT DESCRIPTIONS Independence Creek Independence Creek, a tributary to the Little Truckee River, is located on the Sierraville Ranger District of the Tahoe National Forest within the Independence Creek watershed (Figure 1a). Baseline habitat data was collected along approximately 1,556 meters of channel within the mainstem of Independence Creek and its many tributaries (primarily spring fed). In general, the monitoring site can be characterized as a low to moderate gradient channel (average = 3.5%, sd=1.1, Table 2). Habitat complexity is high within this section of stream due to multiple braided channels within the meadow. Of the 1,556 meters of inventoried channel, approximately 884 meters (57%) were characterized as fast water comprised of low gradient riffle, high gradient riffle, or cascade habitats. Mid‐channel pools and runs made up the majority of the remaining inventoried habitat, at 313 meters (20%), and 285 meters (18%) respectively. The average bankfull width was 4.2 meters and ranged from 1 – 15.2 meters. Backwater habitats had the smallest average bankfull widths (2.2 meters), while high gradient riffles had the largest (4.7 meters). A total of 36 pools were identified within the 1,556 meters of channel with an average residual pool depth of 0.4 meters (sd=0.2) and range of 0.12 to 1.3 meters. Measurement of pool tail fines were used to assess the level of existing fine grained sediment within the 36 identified pool habitats. Because of the low gradient nature of this channel, moderate to high levels of sediment deposition and pool tail fines were expected. However, the level of pool tail fines within Independence 9 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Creek and its tributaries was relatively low (average = 8.6%, sd=20.8, range = 0‐91.3%). Relatively low fine substrate within Independence Creek may be a result of consistent flows being released from Independence Reservoir located upstream of the survey site, as well consistent flows within tributary spring channels. For comparison, Stream Condition Inventory (SCI) monitoring that has occurred from 2000 through 2012 assessing impacts to aquatic habitats resulting from HFQLG activities within the three forests found that stream channels identifies as low gradient “Reference” reaches had an average of 23.5% pool tail fines. The total pieces of large woody debris (LWD) in Independence Creek was 209 throughout the 1,556 meters of channel (approximately 209 pieces per/mile). Riparian hardwood species within the survey site included willow, alder, and aspen. Willow and alder were the dominant riparian hardwoods within the survey area, with both species found within 100% of all surveyed areas. Aspen were only found within 40% of the survey area. Riparian hardwoods in Independence Creek play a vital role in ambient air temperature regulation and stream channel shade, which both play a role in water temperatures. The average channel shade within all surveyed stream reaches was approximately 49% (sd=25.7, range= 6%‐95%). Riparian hardwood species provided an average of approximately 54% of the stream channel cover (range = 10% ‐ 100%), while conifer species contributed the remaining 46% (range = 0%‐90%). Greenline width on either side of the channel averaged approximately 3.1 meters and ranged from 0 to 12.0 meters. Bank stability throughout all habitat inventoried reaches were characterized as stable to moderately stable. The Beaver Pond meadow (QLGIND3, Figure 1a) was a large meadow with a complex of flooded vegetated ponds created by beaver dams that ranged from deep pools to shallow flooded vegetation. While most of the meadow had an open canopy, wetted habitat on the margins was shaded by mature conifers and aspen and large (8‐12 foot high) willow shrubs occurred throughout the meadow. Frogs were found in two of the outlets. One was a small medium gradient stream with rocky substrate that included a mix of boulders, cobble, and gravel. The other was a small, silty medium gradient stream. Habitat data were not collected in this area. Proposed HFQLG treatments within and adjacent to occupied and potential suitable habitat are associated with the Outback Aspen Restoration Project. The Outback project consists of approximately 471 acres of aspen enhancement treatments within RHCAs, which in general extend 300 feet on either side of any perennial stream or 150 feet from the edge of the meadow surrounding Independence Creek and the many small spring‐fed tributaries, whichever is greater. As per direction contained within the HFQLG Act pertaining to vegetation actions within RHCAs, vegetation treatments are not prohibited from occurring within RHCAs, though specific standards and guidelines are integrated into the project to 10 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson protect or enhance habitat qualities. Of the total 471 acres of aspen enhancement, 196 acres are associated with a tributary upstream of the monitoring site, and 36 acres of treatment are proposed within and adjacent to the monitoring site. The Outback project will remove conifers within the RHCA to reduce competition for available resources including sunlight, soil moisture, and potential expansion area for aspen growth. The Outback Project was scheduled for implementation in fiscal year 2011, but was delayed until 2012. Implementation of two of the treatment units associated with the adjacent Sierra Nevada yellow‐legged frog habitat began in late August of 2012. One unit has been completed as of late September. The other unit has been initiated with the north side of the stream channel being completed; however, implementation on the south side of the channel has been halted due to access issues across private lands. Due to the late start of the implementation, the opportunity to fully assess the potential effects of these actions on the frog population and suitable habitat is not possible. An additional land management activity that may be affecting suitable habitat for all life stages of Sierra Nevada yellow‐legged frogs includes active grazing within the survey area, which may have impacts on riparian ground vegetation, riparian hardwoods, bank stability, flood plain connectivity, and hydrology (surface and groundwater) within some sections. Furthermore, Independence Creek supports native and non‐native fish assemblages which have been shown to have an effect on Ranid frog species throughout the Sierra Nevada (Knapp and Matthews 2000). 11 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Figure 1a. Amphibian monitoring sites in the vicinity of Independence creek, Tahoe National Forest, CA. QLGIND1 is the primary monitoring site and QLGIND3 is the Beaver Pond meadow. QLGIND2, QLGIND4, QLGIND5, QLGIND6, and QLGIND8 are additional peripheral sites surveyed. South Fork Rock Creek South Fork Rock Creek is located on the Mt. Hough Ranger District of the Plumas National Forest within the Spanish Creek watershed (Figure 1b). Baseline habitat data was collected along approximately 2,407 meters of channel within South Fork Rock Creek, and was delineated into two separate reaches based on channel gradient. The average gradient of the lower section (2,009 meters in length) is approximately 9% and ranged from 5%‐12%. The upper section (398 meters in length) had an average channel gradient of 3.1%, and ranged from 2%‐5%. Interestingly, the difference in channel 12 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson gradients, and expected difference in slow water and fast water habitats between the two reaches, was not evident. The higher gradient reach was comprised of 91% (1,824 meters) high gradient and low gradient riffles, with the remaining 9% (17 meters) of habitat being comprised of mid‐channel and plunge pools. Similarly, the lower gradient reach was comprised of 97% (356 meters) high and low gradient riffles, and 3% (42 meters) of mid‐channel pool habitat. South Fork Rock Creek can generally be characterized as an intermittent channel with consistent perennial flows during the spring run‐off and into the early summer months, though flows typically cease by mid‐summer and result in long stretches of dry channel and isolated standing water within pool habitats. Because channel conditions were primarily dry during the time that the habitat inventory was completed, assessment of residual pool depths, and pool tail fines was not possible. The average bankfull width for all habitat types averaged approximately 3.6 meters and ranged from 1 ‐ 6.1 meters. A total of 66 pieces of LWD were identified within the total 2,407 meters (44 pieces/mile) of inventoried channel. Stream channel shade within the inventoried stream site averaged approximately 54.9% and ranged from 16% to 94%. One hundred percent of the channel shade was provided by conifer vegetation; riparian hardwood vegetation was not present. South Fork Rock Creek was selected as an amphibian monitoring site for the Meadow Valley HFQLG project. The Meadow Valley project was completed in 2009 and consisted of 5,700 acres of treatment that included group selection, construction of a DFPZ, individual tree selection, and decommissioning of 39.7 miles of road. No pre‐treatment data was collected at South Fork Rock Creek because the Meadow Valley project was completed prior to the initiation of amphibian surveys. 13 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Figure 1b. Amphibian monitoring sites in the vicinity of South Fork Rock Creek, Plumas National Forest, CA. QLG008 is the primary monitoring site. QLGDV1, QLGDV2, QLGDV3, QLGDV4, and QLGDV5 are additional reaches and tributaries surveyed. Lone Rock Creek Lone Rock Creek is located on the Mt. Hough Ranger District of the Plumas National Forest within the Indian Creek watershed (Figure 1c). The reach of Lone Rock Creek where stream habitat conditions were inventoried can be characterized as a low to moderate gradient (average 3.7%, range = 1.5% to 11%) perennial stream with a large boulder component (specifically in the upper sections) and high beaver activity in the lower sections. The monitoring reach was a 1,390 meter section of stream from the private property boundary in Section 17 downstream toward Antelope Lake. Mid‐channel pools were the dominant habitat type, comprising approximately 51% (710 meters) of the reach. Fast 14 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson water habitats comprised approximately 49% (680 meters) of the sites and included high and low gradient riffles, cascades, and runs. A total of 42 pools were identified with an average residual pool depth of approximately 0.6 meters (sd= 0.2) and range of 0.3 meters to 1.0 meters. The average pool tail fines were approximately 55% (sd=31.5) and ranged from 0% ‐100%. This level of pool tail fines exceeds the average pool tail fines observed within both response type reaches (23.5%) and transport type reaches (5.2%) for “Reference” reaches within the HFQLG Pilot Project area. The average bankfull width was approximately 3.5 meters (range = 1.3 meters – 5.8 meters), however, measuring bankfull widths within habitat upstream of beaver ponds was not possible. Average greenline width was approximately 2.3 meters and ranged from 0 to 6.5 meters. High bank stability was noted along the entire reach. Riparian hardwood vegetation was dominated by willow and alder which were identified within 100% of the inventoried reach, in both clumps and long stretches of continuous presence. In general, these willow and alder stands were characterized as being in a younger age class, with little evidence of mature trees. Aspen were identified along approximately 38% of the survey reach, and were characterized as a young age class. Average stream channel shade was approximately 33% (sd=21.6, range= 3% ‐ 76%), with riparian hardwoods providing, on average, approximately 72% (range=3%‐100%), and conifer vegetation providing the remaining 28% (range=0%‐97%). Of note is that the number of beaver dams increased within the Lone Rock survey site from 4 in 2009 within about the first 150 meters of the reach to 13 in 2010 and 12 in 2011 scattered through approximately the lower 1000 meters of the reach. Lone Rock Creek was selected as an amphibian monitoring site for the Moonlight Fire Recovery Project. With the exception of some helicopter units, the majority of Moonlight Fire Recovery treatments were completed in 2010. Of the treatments originally planned (10,366 acres salvage harvest, 4,389 acres of roadside hazard tree removal, and 16,006 acres of reforestation), only 100 acres of roadside hazard treatments were located in the immediate vicinity of the monitoring site. 15 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Figure 1c. Amphibian monitoring site at Lone Rock Creek, Plumas National Forest, CA. QLG007 is the primary monitoring site. Boulder Creek (including Lowe Flat) Boulder Creek is a perennial stream located on the Mt. Hough Ranger District of the Plumas National Forest within the Antelope Lake watershed (Figure 1d). Approximately 1,265 meters of habitat inventory was conducted along Boulder Creek. In general, Boulder Creek can be characterized as a low gradient response reach with an average gradient of approximately 1% (sd=0.6, range = 0.5% to 2%). Habitat in this section of stream was dominated by pool habitat (58%; 731 meters) comprised of mid‐
channel pools, back‐water pools, and dammed pools. The remaining 42% (534 meters) of stream habitat was comprised of fast water including high and low gradient riffles, and runs. The average bankfull 16 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson width was 2.9 meters and ranged from 0.9 to 14 meters. The average greenline width was approximately 1.4 meters and ranged from 0 to 6.7 meters. This section of stream showed high bank stability characteristics throughout the reach. A total of 34 pools were measured, with an average residual pool depth of approximately 0.7 meters and ranged from 0.2 to 2.0 meters. Pool tail fines within these 36 pools were extremely high, and averaged 97.5% (sd=15.8, range=0%‐100%). Although this is a response reach where high sediment loads are expected to deposit, current levels are well above the average pool tail fines observed within other response type channels characterized as “Reference” streams within the HFQLG Pilot Project area which averaged 23.5%. Potential influences on these high sediment loads include the very low channel gradient, extensive beaver activity, braided channels, extensive grazing practices within the meadow and potential lasting effects from the Boulder Fire that occurred in 2006. Average stream channel shade was measured at approximately 37% and ranged from 4% to 90%. Conifer vegetation contributed approximately 54% (range=0%‐100%) of the channel shade, while riparian hardwoods contributed approximately 46% (range=0%‐100%). Willow and alder were the only riparian hardwood types identified in the survey reach. Willow stands were found within 100% of the reach, while aspen were located within less than 10%. In general, these stands were characterized as older stands, with little to no regeneration noted throughout the reach. Habitat data were not collected along the stream section where frogs were found. This section, upstream of Lowe Flat, contains water intermittently, with sections of both flowing and pooled water with observable turbidity. The majority of the stream reach has low to moderate gradients with organic and vegetative substrate, although there is one steep boulder field where water flows sub‐surface. In most sections, the stream channel is generally narrow with dense vegetation dominated by willows intermixed with alders. Canopy openings above the stream do exist either in very small forested sections or directly upstream of beaver dams where the stream has been modified into large flooded wetlands. Boulder Creek was selected as an amphibian monitoring site for the Wildcat HFQLG project. The Wildcat project was in the planning horizon for fiscal year 2011, but due to logistical constraints, no treatments have been completed to date. Actions planned within the Boulder Creek watershed include reduction of overstocked conifer stands, aspen enhancement, decommissioning of roads, planting of riparian hardwood vegetation adjacent to Boulder Creek, stabilization of existing headcuts, and addressing the effects of current grazing practices within meadows, fens, and stream channels adjacent to the survey site. 17 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Figure 1d. Amphibian monitoring sites in the vicinity of Boulder Creek, Plumas National Forest, CA. The primary monitoring site flows through the meadow in Lowe Flat (QLGLF1). Frogs were found upstream on QLG005. QLG006 and QLGBM1 are additional areas surveyed. 18 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Table 2. Summary of Reach‐Wide Habitat Inventories for each survey site. Survey Site Measurement Attributes Wetted Width Bankfull Width Greenline Width Avg. Percent Fines Max. Pool Depth Avg. Residual Pool Depth Pooltail Crest Depth Gradient Percent Shade Percent Hardwood Shade Percent Conifer Shade Independence Creek South Fork Rock Creek Boulder Creek Mean 2.7 4.2 3.1 8.6 0.5 SD 1.9 2.2 2.1 20.8 0.3 Min 0.0 1.0 0.0 0.0 0.2 Max 12.8 15.2 12.0 91.3 1.5 N 69 69 69 34 34 Mean 0.7 3.6 4.3 n/a
0.5 SD 1.0 1.0 1.9 n/a
0.1 Min 0.0 1.0 0.0 n/a
0.2 Max 3.4 6.1 10.2 n/a
0.8 N 90 90 90 42 42 Mean 2.4 3.5 2.3 54.5 0.8 SD 1.3 0.8 1.0 31.5 0.2 Min 0.9 1.3 0.0 0.0 0.5 Max 11.9 5.8 6.5 100 1.2 N 76 76 76 40 40 Mean 1.0 2.9 1.4 97.5 0.8 SD 1.1 2.0 1.2 15.8 0.4 Min 0.0 0.9 0.0 0.0 0.2 Max 4.6 14.0 6.7 100 2.0 36 0.4 0.2 0.1 1.3 34 0.5 0.1 0.2 0.8 42 0.6 0.2 0.3 1.0 40 0.7 0.4 0.2 2.0 36 0.1 0.0 0.0 0.2 34 n/a n/a n/a n/a 42 0.2 0.0 0.1 0.3 40 0.0 0.1 0.0 0.2 17 25 3.5 49.1 1.1 25.7 2.0 6.0 5.6 95.0 25 49 8.0 54.9 3.0 18.4 2.0 16.0 12.0 94.0 14 27 3.7 33.1 2.9 21.6 1.5 3.0 11.0 76.0 16 32 1.1 36.9 0.6 28.0 0.5 4.0 2.0 90.0 25 54.0 27.8 10.0 100 49 0.0 0.0 0.0 0.0 27 71.6 28.8 3.0 100 32 46.1 36.3 0.0 100 25 46.0 27.8 0.0 90.0 49 100 0.0 100 100 27 28.4 28.8 0.0 97.0 32 54.2 36.6 0.0 100 19 Lone Rock Creek N 119 119 119 36 36 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Sierra Nevada Yellow‐legged Frog Abundance and Survival Sierra Nevada yellow‐legged frogs were detected in the four primary monitoring sites and in four of the additional sites (Beaver Pond meadow, QLGIND2, QLGIND6 at Independence Creek, QLGDV2 at SF Rock Creek, see Figures 1a, 1b). Estimated abundances of adults are summarized in Tables 3 ‐ 7. The Independence Creek primary monitoring sites had estimated population sizes of 1 to 14 individuals each year. The Beaver Pond meadow had the largest estimated population size with 35.8 males (SE = 6.30) and 32.7 females (SE = 5.88) in 2011. The smallest populations were at Boulder Creek and SF Rock Creek where only one or two individuals were detected each year. At SF Rock Creek and Lone Rock Creek, population estimates decreased somewhat each year. At Independence Creek, the population estimates from June 2010 were larger than the remainder of the estimates which were made in August. At the other additional sites, only 1‐2 frogs were found each year (Tables 3, 4). Larvae were detected at 3 of the 4 primary monitoring sites and at the Beaver Pond meadow (Tables 3‐7). Multiple age classes of tadpoles were found at Independence Creek, the Beaver Pond meadow, and Lone Rock Creek. Sex ratios were highly variable among sites. The proportion of males ranged from 0‐0.52. In all sites except the Beaver Pond meadow, females were more abundant than males. Only females were detected in some years at most sites (SF Rock Creek and QLGDV1 in 2011, Lone Rock Creek in 2011, Boulder Creek in 2010, 2011). At the three sites where it could be estimated (Independence Creek, SF Rock Creek, Lone Rock Creek), annual survival ranged from 0.57‐0.81 (Tables 3, 5, 6). At Independence Creek, models with time dependent survival could not be parameterized so survival estimates were constant across all sample periods. At SF Rock Creek and Lone Rock Creek, model averaged survival estimates were similar among years. Of the 31 individual adult frogs captured at the monitoring sites surveyed all three years (Independence Creek, SF Rock Creek, and Lone Rock Creek), 42% were captured only one year, 39% were captured two years, and 19% were captured all three years. At Boulder Creek, one of the two marked individuals was found one year and the other both years surveyed. 20 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Table 3. Summary of population and survival estimates for Sierra Nevada yellow‐legged frogs at Independence Creek, Tahoe National Forest (Figure 1a). Model averaged population estimates for Sierra Nevada yellow‐legged frog adults at the primary monitoring site (QLGIND1) are from robust design methods in 2009 ‐2011 and are shown with standard error in parentheses. Subadult and larvae counts are the maximum number observed on a single day. Site ID Metric Life Stage # 2009 # Jun 2010 # Aug 2010 # 2011 QLGIND1 Population Estimate Adult Male 0 2.4 (0.70) 3.2 (0.52) 3.2 (0.43) Adult Female 2.4 (0.93) 7.1 (1.34) 3.2 (0.52) 5.3 (0.58) Survival Adults Maximum Count Subadult 27 5 0.81 (0.20) 17 0..81 (0.20) 8 Larvae 76 0 68 50 QLGIND2 Maximum Count Adult Female 1 0 0 0 QLGIND6 Maximum Count Adult Female 0 0 1 0 Table 4. Summary of population estimates for Sierra Nevada yellow‐legged frogs in the Beaver Pond meadow in the vicinity of Independence Creek (QLGIND3), Tahoe National Forest (Figure 1a). Model averaged population estimates for Sierra Nevada yellow‐legged frog adults in 2010 and 2011 are from Huggins closed capture methods and are shown with standard error in parentheses. 2009 adult counts are numbers of unique tagged individuals. Subadult and larvae counts are the maximum number observed on a single day. Increases in abundances from 2010 to 2011 are likely due to our increased survey effort in 2011. Site ID Metric Life Stage # 2009 # Aug 2010 # 2011 QLGIND3 Population Estimate Adult Male 2 8.5 (2.40) 35.8 (6.30) Adult Female 2 9.9 (2.67) 32.7 (5.88) Maximum Count Subadult 29 74 28 Larvae 5 55 96 21 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Table 5. Summary of population and survival estimates for Sierra Nevada yellow‐legged frogs at South Fork Rock Creek, Plumas National Forest (Figure 1b). Model averaged population estimates for Sierra Nevada yellow‐legged frog adults in the primary monitoring site (QLG008) are from robust design methods and are shown with standard error in parentheses. QLGDV1 adult counts are numbers of unique tagged individuals. Subadult and larvae counts are the maximum number observed on a single day. Site ID Metric Life Stage # 2009 # 2010 3.1 (0.37) 1.0 (0.21) #2011 2.1 (0.41) 0.61 (0.25) 0 QLG008 Population Estimate Survival Adults Maximum Count Subadult 1 1.0 (0.14) 2.0 (0.20) 0.57 (0.22) 0 Larvae 0 0 0 Maximum Count Adult Male No 0 0 Adult Female Survey 2 2 QLGDV1 Adult Male Adult Female 0 Table 6. Summary of population and survival estimates for Sierra Nevada yellow‐legged frogs at Lone Rock Creek, Plumas National Forest (Figure 1c). Model averaged population estimates for Sierra Nevada yellow‐legged frog adults are given from robust design methods and are shown with standard error in parentheses. Subadult and larvae counts are the maximum number observed on a single day. Site ID Metric Life Stage # 2009 # 2010 # 2011 QLG007 Population Estimate Adult Male 2.3 (0.55) 2.2 (0.49) 0 Adult Female 11.3 (1.35) 6.6 (0.90) 6.3 (1.8) Survival Adults 0.78 (0.25) 0.74 (0.28) Maximum Count Subadult 3 7 9 Larvae 0 7 8 Table 7. Summary of Sierra Nevada yellow‐legged frog captures at Boulder Creek (QLG005), Plumas National Forest (Figure 1d). Adult Sierra Nevada yellow‐legged frog counts are the number of unique tagged individuals. Subadult and larvae counts are the maximum number observed on a single day. No frogs were found at the primary stream reach in Lowe Flat. Site ID Metric Life Stage # 2009 # 2010 # 2011 QLG005 Population Counts Adult Male Adult Female Maximum Count No 0 0 Survey 2 1 Subadult 5 4 Larvae 0 1 22 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Distance travelled and Spatial Distribution Within the four day study periods there were a total of 96 recaptures of 45 individual marked frogs (Table 8). On average, frogs travelled 19.9 meters (sd = 28.5) between capture locations. The largest distances travelled were by four frogs at Independence Creek in 2010. These frogs moved distances of 77, 117, 155, and 207 meters between the June and August surveys. Within each survey period they tended to stay in the same place and they were found in similar locations in each of the August surveys. If these four frogs were excluded, the maximum distance between days was 40 m. Excluding the four frogs, females (average = 16.0 m, se = 1.2) travelled slightly farther than males (average=11.0 m, se=2.0). Among years there were 39 recaptures of 32 individual frogs (Table 9). Frogs moved an average of 69.6 meters (sd = 93.7) though the median distance was only 32.8 m. Distances were similar for males and females. The largest observed movement was 481 m, but larger movements out of the study area may have occurred. This was a female that was found on the upper part of the stream reach at SF Rock Creek in 2009, and moved upstream to a pond in a meadow in 2010 and 2011. Table 8. Distances individual PIT tagged Sierra Nevada yellow‐legged frog moved between subsequent recaptures within a four day study period. Distance (m) moved N N individuals recaptures Mean Median SD Min Max Overall 45 96 19.9 13.1 28.5
0 207 68 18.7 14.5 17.1
0 117 Females 30 25 24.4 10.2 48.4
0 207 Males 14 3 10.5 5 18 Subadult 1 8.6 6.7
Table 9. Distances individual PIT tagged Sierra Nevada yellow‐legged frog moved among years. Distance (m) moved N N individuals recaptures Mean Median SD Min Max 39 69.6 2 481 Overall 32 32.8 93.7
29 68.4 28.2 100.5
2 481 Females 22 9 76.6 41.1 2 186 Males 9 78.6
1 42.2 42 42 Subadult 1 42.2 At Independence Creek, frogs were found throughout the monitoring site but the highest densities were in the middle third of the reach, which corresponds with where we found tadpoles. There was no separation of adults and subadults, though subadults generally were found downstream of breeding areas in 2009 and 2010. At SF Rock Creek, adults were found in the same general vicinity at the upper end of the monitoring site on the stream and in a small pond in the meadow at the top of the 23 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson reach, and only one subadult was found. The lower part of the site had more dry sections. At Lone Rock Creek, adults were found more often in the upper part of monitoring site where the stream was less affected by beaver activity. Subadults and tadpoles were found more often in the lower section that overlapped with the beaver activity and had more flooded grassy areas and backwater refuges. At Boulder Creek, frogs were found in or near small pools in the upper part of the stream reach. Subadults were found in a flooded area created by a beaver dam and a single tadpole was found just downstream from the beaver dam in a shallow grassy side pool out of the main flow. Chytrid We collected 234 tissue samples from Sierra Nevada yellow‐legged frogs (80 from adults, 122 from subadults, and 32 from tadpoles). Low levels of Bd (<400 zoospore equivalents) were detected in only 9 Sierra Nevada yellow legged‐frogs. Of the marked individuals, these included a female at Independence Creek that was not infected in 2009 and June of 2010, but had very low levels detected in August of 2010 and 2011, a female at Lone Rock Creek that had Bd only the first of the three years she was captured (2009), and a female at Lone Rock Creek that was only captured in 2009. In addition, low levels of infection were detected in an unmarked adult and 2 subadults at Independence Creek, 2 subadults at the Beaver Pond meadow, and 1 subadult at Lone Rock Creek. Sierra Nevada Yellow‐legged Frog Habitat Usage More than half (67%) of the marked adult frog captures were in the streams, 18% were on shore, and 15% were in backwaters, tributaries, or side channels. The latter were at Independence Creek, a braided stream system in a meadow with numerous tributaries and side channels. Most of the frogs found in these habitats were in water. At Independence Creek and Lone Rock Creek, subadults also were found in backwaters, tributaries and side channels. Forty‐six percent of marked adult frog captures were in pools, 16% in runs and 33% in riffles, but the pattern differed among reaches. Frogs appeared to be selecting pools more often relative to the available habitat at Independence Creek and SF Rock Creek (Figure 2). The few frogs found at Boulder Creek also were found in pools. At Lone Rock Creek, pools were the dominant habitat but frogs were found more often in runs and riffles (Figure 2). At Lone Rock Creek, subadults were found in higher proportions in pools (62%) but no differences were found at the other reaches. Marked adult frogs were found within 1 meter of water (maximum distance= 0.5), and when in water, an average of 0.4 meters of shore (sd = 0.7, maximum = 4.5 m, Table 10). The average water depth where marked adult frogs were found was 0.1 meters (sd = 0.10), but the 24 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson median was half that at 0.05 m; the maximum was 0.8 meters (Table 10). The average wetted width was 3.4 meters (sd = 2.3) with a maximum of 11 meters (Table 10). The average shade where frogs were captured was 56. 5% and ranged from 19% to 98% (Table 10). When in the streams, marked adult frogs were generally found in locations with total cover averaging 52% (sd = 30%, range =0%‐100%) (Table 10). A large portion of this cover was provided by substrate. Frogs were generally found in areas dominated by silt (19% of captures), cobble (33%), or boulders (23%). Frogs located within water were generally found in areas with low herbaceous (average = 14%, sd = 22%, range =0%‐100%), shrub (average = 20%, sd = 30%, range = 0%‐100%), and woody debris (average = 9%, sd = 15%, range = 0%‐80%) cover (Table 10). On shore, marked adult frogs were found in areas with an average of 59% (se = 5%, range = 10%‐100%) total cover (Table 10). Silt was the most common substrate (45% of captures), and frogs were found in in areas with an average of 30% (sd = 32%, range = 0%‐90%) herbaceous, 22% (se = 28%, range = 0%‐100%) shrub, and 10% (sd = 17%, range = 0%‐50%) woody debris cover (Table 10). In addition, subadults were found more often in stream areas with silt whereas adults were found more often in cobble and boulders. Otherwise, with a few exceptions noted above, no differences were found between adults and subadults or between males and females. Figure 2. Comparison of habitat types used relative to available by marked Sierra Nevada yellow‐legged frog adults. Available is the average of percentages of stream length measured in 2009 and 2011. Frog usage is the percent of all captures. Differences in habitat usage were significant at Independence Creek, SF Rock Creek, and Lone Rock Creek (chi‐squared test, alpha<0.05) 25 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Figure 8. Comparison of percent shade at capture locations of marked Sierra Nevada yellow‐legged frog adults relative to available by. All measurements are used. No differences were found between years. 26 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Table 10. Location, stream, cover, and shade habitat attributes for locations where marked frogs were found for all stream reaches combined. Location N Mean SD Distance to Water Distance to Shore Water Depth Wetted Width Cover In water Total Herbaceous Woody Vegetation Woody Debris Cover On Shore Total Herbaceous Woody Vegetation Woody Debris 29 102 131 131 0.1 0.4 0.1 3.4 0.1 0.7 0.1 2.3 Shade Total Conifer Broadleaf N 40 40 40 Min Max 0
0
0
0
0.5
4.5
0.8
11
N Mean SD Min
102 51.8 29.7 0
102 14 21.7 0
Max
100
100
102 19.8 30.1 0 100 102 8.5 15.4 0
80
N 29 29 Mean SD Min
58.6 28.7 10
30.3 31.8 0
Max
100
90
29 22.3 28 0 100 29 9.5 16.8 0
50
Mean SD Min
56.5 25.9 6
43.6 36.7 0
56.7 36.6 0
Max
98
100
100
Tadpoles were found in a variety of habitats. At Independence Creek, tadpoles were found in two areas. The primary area with tadpoles all three years was a tiny spring‐fed tributary with a maximum width of about 1 m. Water depths were only about 0.1 meters in most areas with a maximum depth of about 0.3 m. This area contained a thick layer of orange/red algae with gravel and cobble substrate. In 2009, tadpoles were also found in pools in a side channel with cobble substrate, little vegetation, and a maximum depth of about 0.3 m. There was little to no flow in this area because of a gravel bar that cut off the flow from the main channel. At Lone Rock Creek, tadpoles were found in a shallow (~<0.2 m) flooded area with tall grassy vegetation at the edge of the stream. The adjacent channel was deep (> 1 m). The area was not present in 2009 and was probably created by a beaver dam about 10 meters downstream. Finally, at Boulder Creek, the lone tadpole was found just downstream from a beaver dam in a shallow grassy side pool outside the main flow. 27 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson DISCUSSION Sierra Nevada yellow‐legged frog populations on the four HFQLG monitoring streams were small which corresponds with the species’ well‐documented population declines (Vredenburg et al. 2007, Brown et al. 2011). Abundances of all life stages were low including adults, subadults, and tadpoles. We did find indications of reproduction (tadpoles or subadults) at all four streams, though we found tadpoles at all only three. Historical and current records for lakes document that Sierra Nevada yellow‐
legged frog populations can be quite large. For example, Bradford (1991) reported population sizes of 790 frogs and 1,100 tadpoles at one lake in 1979 in Sequoia National Park, though this population declined later that same summer and was extinct within a decade (also Grinnell and Storer 1924, Pope 1999, Vredenburg et al. 2010, Boiano and Meyers 2010, Brown et al. 2011). In contrast, our largest annual stream population estimate was 2 males and 11 females in 2009 (Lone Rock Creek). To our knowledge, no equivalent historical data exists for stream populations for comparison. In extensive monitoring throughout the Sierran range of the mountain yellow‐legged frog taxa, frogs of any life stage were found in streams in 28 (of 208) watersheds with evidence of reproduction (eggs, tadpoles) in only 10. In most sample reaches, abundances of adults and subadults were small (< 10 frogs, maximum=21). In the two streams with relatively large numbers of tadpoles (1977, 211) only a few adults and subadults were found (C. Brown unpublished data). Vredenburg et al. (2004) surveyed one of these streams in 2003 and found few frogs (<10) and only 58 tadpoles. However, they did find large numbers (547 adults, 178 subadults, 330 tadpoles) in a stream system in the southern Sierra. Survival rates of Sierra Nevada yellow‐legged frogs in our monitoring reaches were relatively high and similar to those found by Matthews and Preisler (2010) in lentic habitats in the southern part of the species’ range. The declines in Sierra Nevada yellow‐legged frog populations have been largely attributed to the introduction of trout to historically fishless lakes in high elevations and to the spread of Bd (Bradford 1989, Knapp and Matthews 2000, Rachowicz et al. 2006). How these risk factors affect stream populations and their role in explaining the small abundances in our monitoring reaches is not known. Fish were found in all the primary monitoring reaches. Fish species were not identified to species, however it can be assumed that species composition included both native and non‐native salmonids. Additonally, these populations within stream and reservoir habitats have been sustained through active stocking practices implemented by the California Department of Fish and Wildlife. We found Bd on only 3 frogs and at low infection levels. It is not known whether Bd played a role in the current small populations. Recent research has found that Sierra Nevada yellow‐legged frogs can persist with low 28 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson levels of Bd infection, and it is a combination of high rates of spread and infection, typically found with large abundances, that cause extinctions of populations (Briggs et al. 2010, Vredenburg et al. 2010). Interestingly, our largest abundances were in the relatively lentic water associated with a beaver dam, where numbers may approach those found currently in some lakes (see Brown et al. 2011). Tadpoles generally were more common in the deep open pools, subadults in open shallower flooded vegetation, and adults in medium sized pools with more vegetation cover and in the adjacent stream channels (pers. obs.). The role beaver may play in creating habitat for the predominantly lentic breeding Sierra Nevada yellow‐legged frogs warrants further investigation (Cunningham et al. 2007). This is particularly true for places where lentic habitat is scarce, such as the HFQLG project area. The few tadpoles we found at Lone Rock Creek and Boulder Creek also appeared to be associated with beaver activity. The ecology of the Sierra Nevada yellow‐legged frog in stream environments is not well known. We found multiple age classes of tadpoles in two of the streams (only one tadpole was found at Boulder Creek) confirming that, similar to the rest of the range, they require multiple years to develop. Based on knowledge from lake habitats, the multi‐year tadpole stage requires breeding habitat that provides a refuge from overwinter freezing (Bradford 1983, Knapp 2005, but see Lacan et al. 2008), summer desiccation (Lacan et al. 2008), and fish (Knapp and Matthews 2000). We spent a limited amount of time looking for potential nearby off‐channel lentic breeding areas including deep spring pools, deep potholes, and ponds or lakes. Although we found a few promising locations, we did not find any tadpoles. Instead, we found tadpoles in or adjacent to the streams. Although the three stream locations were somewhat different (i.e., shallow tributary, streamside bench, small pool), they were all exposed, relatively shallow, and with warm water. These are characteristics typical of tadpole habitat in lentic waters (Bradford 1984, pers. obs.). The movement ecology of Sierra Nevada yellow‐legged frogs in lentic systems has been well‐
studied. In lentic systems, adults move to a variety of other water bodies after breeding and have high site fidelity to these sites (Matthews and Pope 1999, Pope and Matthews 2001, Matthews and Preisler 2010). In telemetry studies on stream systems, Matthews (pers. comm.) and Wengert (2008) found frogs behaving similarly where they move seasonally to different areas, but moved little within seasons. Note that some of the frogs tracked by Wengert et al. (2008) may be foothill yellow‐legged frogs (R. boylei). Indeed, similar patterns also have been documented for this closely related stream‐dwelling frog which, in some systems, moves to tributaries during nonbreeding seasons (Bourque 2008, Gonsolin 2010). Although our monitoring was not designed to address this question and our sample of frogs was 29 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson small, our data generally corroborate these patterns. Distances between capture sites were small within the four day CMR periods, and at Independence Creek, several frogs moved longer distances between June and August surveys. Our data also suggests a high degree of site fidelity; 58% of frogs were captured multiple years, distances among years generally were small, and the four frogs that moved large distances from June to August were found in the same areas each August. Telemetry studies investigating how frogs use the available habitat surrounding our monitoring reaches would be illuminating given the differences among reaches in habitat and the surrounding landscape. We did find a few frogs during our additional searches, but no areas with large numbers other than the Beaver Pond area. Similar to other studies, we found most of the frogs (67%) in the streams and when on shore, within 1 meters of water; we did not, however, search extensively away from water (Zweifel 1955, Mullally and Cunningham 1956, Matthews pers. comm., Wengert 2008). We did find frogs basking on shore or in backwaters, tributaries or side channels. Frogs generally seemed to be selecting pool habitats, with the exception of Lone Rock Creek, which was increasingly affected by beaver activity. At Lone Rock Creek, tadpoles and subadults were found more often adjacent to the deep runs and pools behind beaver dams, whereas adults were found more often in the riffles upstream. Cover appeared to be important and generally took the form of silt, cobble, or boulder substrate. Boulders and rocks also provide basking sites. In lakes, Knapp et al. (2003) found a positive association with the percent of silt in the littoral zone among other variables less comparable with our study. Matthews and Pope (1999) found that frogs in August selected for undercut banks and willows, and against bedrock habitats. Summary of affects to aquatic habitat resulting from implementation of HFQLG Activities The goal of this monitoring effort was to analyze the impacts to Sierra Nevada yellow‐legged frogs and their habitats as a result of implementing management activities described within the HFQLG Pilot Project Act. However, because the timing of this effort did not line up with implementation of projects that would have allowed for assessing pre and post‐project population and habitat conditions, we will use results from the Stream Condition Inventory (SCI) monitoring within the HFQLG Project area that assessed changes in conditions to aquatic habitats following project implementation. These changes in aquatic habitat obtained through SCI monitoring can then be compared to the preferred habitat for Sierra Nevada yellow‐legged frogs to determine whether implementation of HFQLG activities pose a risk of altering occupied or potential suitable habitat for the species. For a detailed analysis of 30 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson impacts to perennial stream channels, refer to the HFQLG Monitoring Stream Condition Inventory Cumulative Report (USDA 2013). Land management activities that have been implemented across the HFQLG Project area can be lumped into five distinct catagories. These include: 1. Vegetation and Fuels Treatments‐ actions associated with this objective generally fell within the prescription of Defensible Fuel Profile Zones (DFPZs), area thinning, group selections, mastication, and treatment of existing ground fuels. In general, these actions were implemented to reduce the risk of high intensity wildfire across the landscape, provide safe areas for firefighting personnel during suppression activities, and improve forest stand health. 2. Aspen Enhancement‐ health and distribution of aspen stands within the HFQLG Project area have been found to be in a declining trend as a result of conifer encroachment, grazing, browsing by native ungulates, and wildfire suppression actions over the past century. Implementation of this type of activity generally includes removal of encroaching conifer species within and surrounded existing aspen stands, and may include post project fencing to reduce browsing. A portion of these actions that have been implemented were located within riparian habitat conservation areas (RHCAs) that may be located adjacent to or within potential suitable or occupied habitat for Sierra Nevada yellow‐legged frogs. 3. Near‐Stream Road/Culvert Decommissioning: these actions include decommissioning of roads to reduce overall road densities, decrease potential sedimentation to aquatic habitats, and decrease level of unneeded roads no longer needed for long‐term management. This category also includes upgrading of existing culverts to pass flows during large runoff events to reduce potential for road failure and associated risk of large sediment input, as well as providing adequate conditions for passage of aquatic organisms to upstream habitat. 4. Stream and Meadow Enhancement: Actions included in this category include improvement of stream bank conditions through planting of riparian hardwoods and placement of rock and gravel. Some of these actions, such as pond & plug stream restoration, entail diverting stream courses from their original channels into remnant (historic) channels. 5. Wildfire: Although wildfire is not a land management action, a number of watersheds within the HFQLG Project area were burned by wildfires. As a result changes in aquatic habitat, and riparian vegetation often occurred. When assessing the impacts of HFQLG projects upon Forest Sensitive amphibian species, the focus has been on the potential direct and indirect effects to occupied and potential suitable aquatic and 31 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson terrestrial habitats located within riparian areas as well as potential direct effects to the frogs themselves. Therefore, those actions that are located within close proximity to suitable habitat have the greatest risk of potentially affecting habitat. These effects may not necessarily be harmful to potential suitable habitat; in some cases, effects may benefit or enhance habitat. The most likely impact to habitat resulting from those actions listed above, include but are not limited to: 1) Increased sediment to stream channels as a result of mechanical ground disturbance and removal of ground cover, 2) Increased water and ambient air temperatures, which may actually be a benefit to the frogs, through reduction in canopy cover within RHCAs and over aquatic habitats as a result of thinning operations, and 3) Alterations to floodplain connectivity, riparian vegetation, and off‐channel habitat. In general, the results of the SCI Monitoring conducted between 1997 and 2012 showed that in general, implementation of HFQLG land management activities did not result in significant adverse impacts to perennial stream channel habitat. Increases in sediment following project activities were limited to actions that occur directly adjacent to or within stream channels, and included road decommissioning, culvert replacement, and wildfire. Implemented actions that resulted in reduced canopy cover, which has been linked to increased water and ambient air temperatures within riparian areas were limited to aspen enhancement. DFPZ and area thinning actions did not result in significant reductions in stream channel shade, and increases in water temperature were not detected. Three out of the five SCI monitoring sites developed to assess impacts from aspen enhancement activities determined that significant decreases in channel shade did occur. Changes in floodplain connectivity were not detected in any of the SCI Monitoring sites. Changes in this parameter would likely occur as a result of large flow events that result in down‐cutting of channels, extensive bank erosion, and formation of head‐cuts. Due to the scale of vegetation treatments on a subwatershed scale, implementation of HFQLG activities are unlikely to result in measurable increases in water yield or flow velocities. Mitigation features in the development of HFQLG projects include measures to protect or enhance bank stability within stream channels through the implementation of equipment exclusion zones, maintaining adequate bank stability trees, promoting riparian vegetation within RHCAs and implementation of Best Management Practices. Mitigation features were further developed to meet the Riparian Management Objects included in the HFQLG Act to maintain or enhance riparian and aquatic habitats for native flora and fauna species. 32 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Management Recommendations 1) Maintain or enhance habitat diversity: the results from this study indicate that Sierra Nevada yellow‐legged frogs utilize a diverse range of aquatic and terrestrial habitats. a. Increase aquatic habitat diversity through maintaining or enhancing not only those habitats types within the main channel (pools, riffles, runs, and backwater), but also backwaters, side channels, springs, and cover substrate. b. When developing projects that include vegetation manipulation within riparian areas, promote a wide range of forest canopy cover adjacent to suitable habitat. This could be accomplished through leaving clumps of dense conifers, and creating gaps in the canopy to increase basking opportunities for frogs. c. Promote growth of riparian vegetation, including hardwoods, adjacent to stream channels. Identify opportunities for planting hardwoods along stream channels. 2) Populations are very small and isolated, therefore give all occupied habitats special considerations when in proposed project areas. 3) Identify opportunities for stream bank stabilization projects. 4) Implement sediment reduction actions such as stormproofing of the existing road network adjacent to and upstream of suitable and occupied habitat. 5) Prioritize aquatic organism passage projects, such that actions won’t result in reintroduction of fish species to previously fish‐free habitats that are currently occupied by Sierra Nevada yellow‐
legged frogs. 6) Conduct additional surveys during times of breeding to identify preferred habitat, and identify potential habitat improvement projects. 7) Where populations occur, ensure use of mechanical equipment and ground disturbance does not occur within occupied suitable habitat. 8) Where needed, identify potential actions to restore floodplain connectivity. 9) Development of land management activities within or in the vicinity of occupied or potential suitable habitat should be driven by site specific conditions. 10) For projects implemented within or in the vicinity of occupied habitat continue pre‐ and post‐
treatment monitoring of populations and habitat conditions. 33 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson LITERATURE CITED Amstrup S.C., T.L. McDonald, and B.F.J. Manly (Eds.). 2005. Handbook of Capture‐Recapture Analysis. Princeton University Press, Princeton, NJ. Boiano, D., and E. Meyer. 2010. Mountain yellow‐legged restoration project: 2009 Field season summary. Sequoia and Kings Canyon National Parks. 56 pp. Boulanger, J., G.C. White, B.N. McLellan, J. Woods, M. Proctor, and S. Himmer. 2002. A meta‐analysis of grizzly bear DNA mark‐recapture projects in British Columbia, Canada. Ursus 13:137‐152. Bourque, R.M. 2008. Spatial ecology of an inland population of the foothill yellow‐legged frog (Rana Boylii) in Tehama County, California. Humboldt State University, Arcata, CA. 107 p. M.A. thesis. Boyle, D.G., D.B. Boyle, V. Olsen, J.A.T. Morgan, and A.D. Hyatt. 2004. Rapid quantitative detection of chytridiomycosis (Batrachochytrium dendrobatidis) in amphibian samples using real‐time Taqman PCR assay. Diseases of Aquatic Organisms 60:141‐148. Bradford, D. F. 1983. Winterkill, oxygen relations, and energy metabolism of a submerged dormant amphibian, Rana muscosa. Ecology 64:1171‐1183. Bradford, D. F. 1984. Temperature modulation in a high elevation amphibian, Rana muscosa. Copeia. 1984:966–976. Bradford, D.F. 1989. Allotopic distribution of native frogs and introduced fishes in high Sierra Nevada lakes of California: implication of the negative effect of fish introductions. Copeia 1989:775–778. Bradford, D.F. 1991. Mass mortality and extinction in a high‐elevation population of Rana muscosa. Journal of Herpetology 25:174–177. Briggs, C.J., R.A. Knapp, and V.T. Vredenburg. 2010. Enzootic and epizootic dynamics of the chytrid fungal pathogen of amphibians. Proceedings of the National Academy of Sciences, USA. 107:9695–
9700. Brown, C., L. Wilkinson, and K. Kiehl. 2011. Status of the mountain yellow‐legged frog, Yosemite toad, and Pacific Chorus frog in the Sierra Nevada, CA: results from the first monitoring cycle of the USDA Forest Service Sierra Nevada Amphibian Monitoring Program. Internal Report. 51 p. Burnham, K.P., and D.R. Anderson. 2002. Model Selection and Multi‐model Inference: A Practical Information‐theoretic Approach, 2nd Edition. Springer‐Verlag, New York, NY, 488 p. California Fish and Game Commission. 2012. Notice of findings: Southern mountain yellow‐legged frog (Rana muscosa), Sierra Nevada yellow‐legged frog (Rana sierrae). February 14, 2012. 1 p. Cunningham, J.M., A.J.K. Calhoun, and W.E. Glanz. 2007. Pond‐breeding amphibian species richness and habitat selection in a beaver‐modified landscape. The Journal of Wildlife Management 71:2517‐
2526. Frías‐Alvarez, P., V. T. Vredenburg, M. Familiar‐López, J. E. Longcore, E. González‐Bernal, G. Santos‐
Barrera, L. Zambrano, and G. Parra‐Olea. 2008. Chytridiomycosis survey in wild and captive Mexican amphibians. EcoHealth 5:18‐26. 34 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson Gonsolin, T.E. 2010. Ecology of foothill yellow‐legged frogs in Upper Coyote Creek, Santa Clara County, Ca. San Jose State University, San Jose, CA. 133p. M.S. thesis. Grinnell, J., and T.I. Storer. 1924. Animal life in the Yosemite. University of California Press, Berkeley, California, USA, 752 p Heyer, W.R., M.A. Donnelly, R.W. McDiarmid [et al.] (Eds.) Measuring and monitoring biological diversity: standard methods for amphibians. Smithsonian Institution Press, Washington, DC., USA. Kendall, W.L., and J.E. Hines. 1999. Program RDSURVIV: an estimation tool for capture‐ recapture data collected under Pollock’s robust design. Bird Study 46:S32‐S38. Knapp, R.A. 2005. Effects of nonnative fish and habitat characteristics on lentic herpetofauna in Yosemite National Park, USA. Biological Conservation 121:265–279. Knapp, R.A. and K.R.Matthews. 2000. Non‐native fish introductions and the decline of the mountain yellow‐legged frog from within protected areas. Conservation Biology 14:428–438. Knapp, R.A., K.R.Matthews, H.K. Preisler, and R. Jellison. 2003. Developing probabilistic models to predict amphibian site occupancy in a patchy landscape. Ecological Applications 13:1069–1082. Laake, J. 2010. RMark: R Code for MARK Analysis. R package version 1.9.6. Lacan, I., K. Matthews, and K. Feldman. 2008. Interaction of an introduced predator with future effects of climate change in the recruitment dynamics of the imperiled Sierra Nevada yellow‐legged frog (Rana sierrae). Herpetological Conservation and Biology 3:211–223. Matthews, K.R, and K.L. Pope. 1999. A telemetric study of the movement patterns and habitat use of Rana muscosa, the mountain yellow‐legged frog, in a high‐elevation basin in Kings Canyon National Park, California. Journal of Herpetology 33:615‐624. Matthews, K.R., and H.K. Preisler. 2010. Site fidelity of the declining amphibian Rana sierrae (Sierra Nevada yellow‐legged frog). Canadian Journal of Fisheries and Aquatic Sciences 67:243–255. Mullally, D.P., and J.D. Cunningham. 1956. Ecological relations of Rana muscosa at high elevations in the Sierra Nevada. Herpetologica 12:189–198. Pollock, K.H. 1982. A capture‐recapture design robust to unequal probability of capture. Journal of Wildlife Management 46:752–757. Pope, K.L. 1999. Mountain yellow‐legged frog habitat use and movement patterns in a high elevation basin in Kings Canyon National Park. San Luis Obispo, CA: California State Polytechnic University. 64 p. M.S. thesis. Pope, K.L., and K.R.Matthews. 2001. Movement ecology and seasonal distribution of mountain yellow‐
legged frogs, Rana muscosa, in a high‐elevation Sierra Nevada basin. Copeia 2001:787–793. Pradel, R. 1996. Utilization of capture‐mark‐recapture for the study of recruitment and population growth rate. Biometrics 52:703–709. R Development Core Team. 2009. A language and environment for statistical computing. R foundation for statistical computing, Vienna. http://www.r‐project.org/. Rachowicz, L.J., R.A. Knapp, J.A.T. Morgan, M.J. Stice, V.T. Vredenburg, J.M. Parker, and C.J. Briggs. 2006. Emerging infectious disease as a proximate cause of amphibian mass mortality. Ecology 87:1671‐1683. 35 QLG Amphibian Monitoring Foote, Brown, Kiehl, Wilkinson U.S. Department of Agriculture, Forest Service. 1998. Sensitive Species List for the Pacific Southwest Region. USDA Forest Service, Pacific Southwest Region, Vallejo, CA. Forest Service Manual 267. U.S. Department of Agriculture, Forest Service. 2013. HFQLG Monitoring Stream Condition Inventory (SCI) Cumulative Report. U.S. Department of the Interior, Fish and Wildlife Service. 2003. Endangered and threatened wildlife and plants; 12‐month finding for a petition to list the Sierra Nevada distinct population segment of the mountain yellow‐legged frog (Rana muscosa). Federal Register 68:2283–2303. U.S. Department of the Interior, Fish and Wildlife Service. 2007. Endangered and threatened wildlife and plants; 12‐Month finding on a petition to list the Sierra Nevada distinct population segment of the mountain yellow‐legged frog (Rana muscosa). Federal Register 72:34657–34661. Vredenburg, V., T. Tunstal, R. Bingham, J. Yeh, S. Schoville, C. Briggs, and C. Moritz. 2004. Patterns of habitat use and movement of Rana muscosa in the northern Sierra Nevada with comparisons to populations in the southern Sierra Nevada, with additional information on the biogeography of the species. Final Report for California Department of Fish and Game, Habitat Conservation Planning Group and the USDA Forest Service. Vredenburg, V.T., R. Bingham, R.A. Knapp [et al.]. 2007. Concordant molecular and phenotypic data delineate new taxonomy and conservation priorities for the endangered mountain yellow‐legged frog. Journal of Zoology 271:361–374. Vredenburg, V.T., R.A. Knapp, T.S. Tunstall, and C.J. Briggs. 2010. Dynamics of an emerging disease drive large‐scale amphibian population extinctions. Proceedings of the National Academy of Sciences, USA 107:9689–9694. Wengert, G. 2008. Habitat use, home range, and movements of mountain yellow‐legged frogs (Rana muscosa) in Bean and Spanish Creeks on the Plumas National Forest. MGW Biological and Klamath Wildlife Resources. White, G.C. and K. P. Burnham. 1999. Program MARK: Survival estimation from populations of marked animals. Bird Study 46 Supplement:120‐138. White, G.C., D.R. Anderson, K.P. Burnham, and D.L. Otis. 1982. Capture‐Recapture and Removal Methods for Sampling Closed Populations. Los Alamos National Laboratory, LA‐8787‐NERP, Los Alamos, NM, 235p. Zweifel, R.G. 1955. Ecology, distribution, and systematics of frogs of the Rana boylei group. University of California Publications in Zoology. 54:207–292. 36