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II. METHODOLOGY
This section presents the protocols for the Survey and Manage amphibian species, covered by Component/Strategy 1 and 2. Each subsection (A, B, C, D and E) presents the protocol for a different species or pair of species. These subsections CAN BE READ SEPARATELY, using the general Introduction to provide overall context, and following with subsequent sections (III, etc). The Van Dyke's salamander protocol makes references the Larch Mountain protocol, and hence, familiarity with both will be needed.
A. Survey Protocol for the Del Norte Salamander (Plethodon elongatus)
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 Del Norte salamander (Plethodon elongatus; PLEL) 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; these should be spaced by at least a 21 day interval between surveys and are to 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 (Olson et al. 1996, in prep.) 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.
PLEL:
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, a scientific collecting permit from California Fish & Game is required for handling this salamander. Taking requires an additional letter of permission.
Survey Procedures
1. Spatial and Temporal Aspects.
a. Site location.
This species occurs in southwestern Oregon and northwestern California. It ranges from near Port Orford, Curry County, and Powers, Coos County, Oregon, to near Orick, Humbolt County, California. It occurs inland to near Salyer, Trinity County, and eastern Seiad Valley, Siskiyou County, California, and Josephine County, Oregon. These boundaries define the potential range of this species, within which surveys may be triggered if appropriate habitat is found at a site proposed for ground-disturbing activities.
This species is found predominantly in forested talus situations (Herrington 1988). It is typically associated with rocky substrates in mixed conifer-hardwood forests (Olson et al. 1996, in prep.), in upland habitats, slope valleys, and riparian areas (Blaustein et al. 1995). In one California study (Welsh and Lind 1995), habitat for PLEL was found to be generally composed of 1) a mixed coniferous/hardwood late seral stage forest with a closed, multi-story canopy; 2) cool, moist microclimate with moss and fern ground cover, lichen downfall, and a deep litter layer; and 3) rocky substrates dominated by cobble (Welsh and Lind 1995). Although this is considered an "old-growth associate" (see Blaustein et al. 1995), this salamander occurs in younger forest stands, and in the marine-influenced coastal zone, forest age may have no influence on presence or abundance (Diller and Wallace 1994; 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 PLEL should include appropriate habitat in the form of surface rock in addition to other surface 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, and animals may have more periods of activity. The preferred survey season is spring.
Number of Site-Visits - Each site should be visited a total of 3 times over the course of the spring or fall rainy season during appropriate environmental conditions (see below) unless presence is established. AT LEAST ONE SURVEY SHOULD BE CONDUCTED DURING APPROPRIATE CONDITIONS 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. With this sampling interval, it is possible to complete a survey effort within the preferred sampling season, spring. However, attention should be paid to environmental conditions that constrain surveys, itemized below.
2. Environmental Conditions.
The activity patterns of PLEL 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 - Relative humidity should be a minimum of 45%. At potential sites surveyed for PLEL, the air temperature should fall between 9-25oC. 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, 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 habitat 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. If it is decided 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 to 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, Del Norte 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 PLEL 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 PLEL 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 survey 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 mostly comprised of large boulders and large outcrops are not readily sampled by the hand-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 information 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 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, "moving rules" may be applied. Searchers should spend 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 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 - for Survey and Manage species, describe capture location in words, mark and map site. Individual capture locations might be needed if finer-scale delineation of populations is needed.
All captures are to be released as close to the 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 PLEL is found, searching can 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 should be considered occupied. The full extent of this occupied suitable habitat should be delineated. If suitable habitat is separated by no more than 75 meters, then it generally also should be considered occupied. If there is doubt as to the occupancy status of suitable habitat near a known site, survey the site using this same survey protocol. This may include contiguous talus 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 apparently unoccupied habitat should be considered, especially in regard to desired future conditions, population dynamics, and connectivity issues. Conservative measures are recommended when dealing with this type of rare endemic vertebrate species.
