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B. Survey Protocol for the Siskiyou Mountains Salamander (Plethodon stormi)
David R. Clayton - USDA Forest Service, Rogue River National Forest, Applegate RD, 6941 Upper Applegate Rd., Jacksonville, OR 97530
Lisa M. Ollivier - USDA Forest Service, Pacific Southwest Research Station, 1700 Bayview Drive, Arcata, CA 95521.
Hartwell H. Welsh, Jr. - USDA Forest Service, Pacific Southwest Research Station, 1700 Bayview Drive, Arcata, CA 95521.
Introduction
This survey protocol is for determining the presence or absence of individuals and populations of the Siskiyou Mountains salamander (Plethodon stormi; PLST) on proposed managed sites. As a general guide, appropriate habitats within proposed sites for ground-disturbing activities should be surveyed for presence/absence using a time-constrained search technique (TCS; Welsh 1987), for 4 person-hours per 10 acres of habitat during each site visit. Searching begins at the center of a habitat patch, and circles outward to fully cover habitat. To designate absence, three site visits are required. Site visits should be spaced by at least a 21 day interval and should be conducted during appropriate environmental conditions.
Read the entire document before initiating any survey.
1. Prerequisites for Performing Surveys.
This protocol is only to be employed by biologists trained in terrestrial salamander species identification.
Prior to field work, review the literature for historical information and all available resources to determine the current known range and habitat for this species. The management recommendations for Survey and Manage amphibian species provides the most comprehensive and up-to-date information for these salamanders. Several other sources of literature on the basic biology and ecology of these animals are available (Blaustein et al. 1995; Leonard et al. 1993; Nussbaum et al. 1983).
2. State Regulations.
The states of Oregon and California have strict requirements for both the handling and collecting of these animals. Capture and handling is necessary to identify these salamanders, thus the following regulations are to be followed.
PLST:
In Oregon, this is a State Sensitive species, listed in the Vulnerable category, and considered Protected wildlife (OAR 635-44-130). A permit from the Oregon Department of Fisheries and Wildlife is required to capture or take this species.
In California, this is a State Threatened species and it is prohibited to handle these organisms without a Memorandum of Understanding in place with the California Department of Fish & Game. Taking, including collection of Voucher specimens, is generally prohibited and requires an additional letter of permission. The state needs to be notified if any incidental mortality occurs, and specimen needs to be preserved and routed as per their direction.
Survey Procedures
1. Spatial and Temporal Aspects.
a. Site location.
This species has an extremely restricted range, occurring in a small area (about 375 square km) of southern Oregon and northern California. It is found in the Applegate River drainage, in southwestern Jackson County and southeastern Josephine County, Oregon, and in the Klamath River drainage, northern Siskiyou County, California (Olson et al. 1996, in prep.).
Habitat for this species is forested talus. This salamander appears to occur in forested stands with a high percent of canopy closure (Olson et al. 1996, in prep.).
If the potential managed site is near the edge of the species' range and > 25 miles from any known locality, you do not need to conduct this survey.
The site to be sampled for PLST should include appropriate habitat in the form of surface rock. Sites occupied by PLST generally have rock talus substrate with at least some cobble-sized rock that serve as cover objects. Appropriate habitats within both the proposed project area and a 180 m perimeter area surrounding the proposed project area (Fig. 1) should be surveyed.
Discrete pockets of habitat that are greater than 75 m apart (edge-to-edge with no intervening habitat) should be considered separate and require separate surveys. If sites are within 75 m of each other, they can be considered under the same survey procedures.
b. Survey timing.
Seasons - Sampling for animals should occur during the appropriate months:
late fall through early winter (late October to early December) and late winter to late spring (March to mid-May). These times coincide with the fall and spring rainy seasons (see below). Generally, spring offers a longer period of time with appropriate conditions for sampling.
Number of Site-Visits - Each site should be visited a total of 3 times over the course of the spring or fall rainy seasons (see environmental conditions, below), unless presence is established. AT LEAST ONE SURVEY SHOULD BE CONDUCTED IN THE SPRING. Sampling periods should be separated by at least 21 days to allow for site conditions to develop in response to weather regimes and to provide a sufficient time interval to allow seasonal salamander activity to be triggered. Weather events may cause longer periods to pass between sampling. With this sampling interval, it may be possible to complete a survey effort within a single sampling season. However, attention should be paid to environmental conditions that constrain surveys, itemized below.
2. Environmental Conditions.
The activity patterns of PLST are highly dependent on local environmental factors such as humidity and temperature. These factors should be taken into careful consideration when determining when to sample for these animals. The following conditions should be met before sampling may proceed:
Air conditions - The air temperature and humidity should meet the following criteria. Relative humidity of the site should be a minimum of 45%. At potential sites surveyed for PLST, the air temperature should fall between 8-20oC (D.Clayton, pers. obs.). Measures should be taken at about chest height.
Freezing temperatures at a site during the night prior to a survey will cause the salamanders to retreat down into the talus, rendering them difficult to catch by the search technique. Overnight freezing air temperatures at a site should preclude sampling on the following day.
Soil conditions - The soil temperature and humidity should meet the following constraints. The soil temperature, taken 10 cm below the surface, should fall between 4.5-20oC. As a qualitative measure of soil humidity, soil below the first layer of rock within the area being searched should be moist to the touch. If the soil relative humidity can be reliably quantified, it should be measured for soil and litter below the duff layer, and be a minimum of 10% (Welsh, unpub. data).
3. Reference Sites.
These salamanders are highly sensitive to local climate shifts. When possible, we recommend the use of Reference Sites to determine if these animals may be active on a given day near the site to be surveyed. A Reference Site may be a historic site or even a road cut with the appropriate microhabitat that supports a population. A Reference Site should be located in the same subdrainage and at or near the elevation of the survey site to be informative about potential salamander activity on the survey site. If no individuals are found at the Reference Site, it is likely that environmental conditions are not suitable and salamander sampling will not be effective and should not be conducted.
4. Detection.
Presence within the site is established by the capture of one or more salamanders at a site. If presence has been established, no further site visits as described by this protocol are then necessary and the entire area of suitable habitat is designated the known site. To further refine site-delineation, additional surveys will be needed. This is discussed at the end of the protocol.
Absence can only be designated if each site has been sampled 3 times, under appropriate microclimatic conditions, and no individuals are found.
5. Voucher Specimens.
Preserved voucher specimens are not required for this species, due to its status of concern and the required training of field personnel in species identification should reduce identification errors. Photographic vouchers are suggested. This animal is not easily mis-identified, once its key characters have been assessed. If there is doubt as to the identification of a captured salamander, local species-experts can be sought to verify the identity of the animal.
Survey Method
1. Prior to sampling:
Review Survey Area
A contour map covering the specific proposed project area (e.g., forest management activity, recreational development) is needed when conducting a survey. From maps and field verification of site conditions, Siskiyou Mountains salamander habitats (i.e., pockets of talus or rocky substrate) should be delineated within the project area boundary and the 180 m perimeter area. These comprise the survey areas of the site.
Thus, the survey area is defined by the habitat proposed to be affected by the management activity. The construction of a trail across a talus slope may require a much more restricted survey than an extensive regeneration harvest. However, if there is little PLST habitat in the proposed harvest site, survey effort may be reduced in that scenario as well.
Survey time can be estimated once the extent of the PLST habitat is known for the proposed project area. Timing of a survey is scaled to the size of the habitat area using the guideline of 4 person-hours per 10 acres of habitat per site visit. For example, a two-person field crew may complete the searching of a 5 acre habitat within one hour or a 50 acre habitat in ten hours.
Location of plot center.
The time-constrained search begins at the plot center. To find this location, systematically walk the proposed project area to locate areas containing the greatest concentration of surface rock of searchable size (easily turned by hand; remember to replace rocks and other cover objects in original position after searching, to preserve habitat quality). Areas with cover primarily comprised of large boulders and large outcrops are not readily sampled by the search technique. There may be more than one area with suitable substrate within a proposed project area. All areas within the proposed project area possessing suitable habitat should be surveyed for occupancy. Habitats that are further than 75 m apart require separate surveys, and should be reported separately.
Complete the following on the data form (See Appendix 1):
a. Site location.
b. Time and date.
c. Observer name/s.
d. Weather. (record and measure at plot center prior to sampling)
e. Air conditions.
Record air temperature and relative humidity (chest height measures) at the start and end of surveys. If air conditions are not within the bounds outlined in the Survey Procedures section, surveys should not be conducted.
f. Soil conditions.
Five measurements of these variables are needed to validate survey conditions at the beginning of the survey period. If soil/substrate conditions are not within the bounds previously outlined, surveys should not be conducted. The sites for the measures are located as follows:
Site 1. Locate center of plot to be sampled. Measure soil temperature and describe soil humidity.
Site 2. Stand at plot center, select a random compass direction by looking at the seconds-hand of a watch, and walk 15 m in the direction the hand pointed. Measure soil temperature and assess relative humidity. A random number from 0 to 359 can be used to determine the aspect of the direction to walk if searchers have only digital watches.
Site 3. While standing at site 2, select a random compass direction as described for site 2, walk 15m, and take measures.
Sites 4 and 5. Repeat as described for site 3.
g. Canopy closure.
Record canopy closure (%) with densiometer at each soil survey station, 1-5, to characterize site condition (see data form, Appendix 1).
2. Time-constrained search.
Begin searching by hand near the plot center. Turn cover objects, carefully lift moss mats, and sift leaf litter as you systematically move around the area. Expand searching out in concentric circles from the plot center. Please note: No potato rakes are to be used. To ensure that searchers extensively sample the habitat, the following "moving rules" may be applied. Searchers should move about the site, spending no more than 10 minutes searching a small area (whether captures are occurring or not). After 10 minutes of intensive searching in a small area, searchers should move 20 m away, along the designated circular or spiral path, and begin searching again. When moving to a new site or handling a capture (recording information) the timer stops. Time of search applies only to time spent actively searching for animals. Keep track of time each observer spends searching.
If animals are captured record the following information:
a. Species - four-letter code (see code sheet) determined by identification keys provided during field training. Record all amphibian species captured.
b. Stage - juvenile/subadult or adult.
c. Capture location - describe in words, mark and map site. Individual locations might be needed if finer-scale delineation of populations is required.
All captures are to be released as close to original capture location as possible. While searching, attempt to return rocks and other large cover objects back to original positions. Replace moss mats, where possible.
When an individual PLST is found, searching efforts may be stopped (record time), "presence" is designated, the entire habitat is designated occupied (see below), and the habitat becomes a known site and is entered into the known site database.
Delineation of Occupied Sites.
All suitable talus habitat, as determined by a qualified biologist, that is contiguous with an occupied site will be considered occupied. The full extent of the occupied suitable habitat should be delineated. If suitable habitat is separated by no more than 75 meters, then it should also be considered occupied. If there is doubt as to the occupancy status of habitat near a known site, survey the area using this same survey protocol. This may include contiguous talus habitats or adjacent non-talus areas. Unoccupied habitats may be identified by additional surveys to further delineate sites. However, the potential ecological value of contiguous but possibly currently unoccupied habitat (in terms of desired future conditions, population dynamics, and connectivity) should be considered. Conservative measures are recommended when dealing with this type of rare endemic vertebrate species.
