Draft: 11 August 2007
King’s River Project:
STUDY PLAN:
Links between landscape condition and survival and reproduction of fishers
in the Kings River Experimental Range
Project # xxxxxx
Craig Thompson
Research Wildlife Ecologist
US Forest Service
Pacific Southwest Research Station
Sierra Nevada Research Center
Fresno, CA
Kathryn Purcell
Research Wildlife Biologist
US Forest Service
Pacific Southwest Research Station
Sierra Nevada Research Station
Fresno, CA
Approved:
/Peter A. Stine/
Date:
13 August 2007
TABLE OF CONTENTS
I.
Introduction...................................................................................................................................... 3
II.
Fisher: Overview of Status and Research Needs ............................................................................. 4
Status................................................................................................................................... 4
Habitat associations ........................................................................................................... 6
Potential limiting factors .................................................................................................... 7
Research needs ................................................................................................................... 8
III.
Study Objectives and Design ........................................................................................................... 9
IV.
Specific Research Questions and Hypotheses .................................................................................11
V.
Methods ...........................................................................................................................................15
Field methodology ..............................................................................................................15
Data analysis ......................................................................................................................17
VI.
Quality Assurance and Control........................................................................................................21
Standardization of protocols...............................................................................................22
Training in field methods....................................................................................................22
Oversight during data collection ........................................................................................22
Quantifying sources of error...............................................................................................22
VII.
Animal Care and Use .......................................................................................................................23
VIII.
Radio Telemetry and Communication .............................................................................................23
IX.
Data Management and Archiving ....................................................................................................23
X.
Expected Products............................................................................................................................24
XI.
Opportunities for Partnerships and Collaboration ...........................................................................25
XII.
External Communication and Coordination ....................................................................................25
XIII.
Statistical Review.............................................................................................................................25
XIV.
Budget, Staff, and Time Requirements............................................................................................26
XV.
Health and Safety.............................................................................................................................27
XVI.
NEPA Compliance...........................................................................................................................27
XVII. Literature Cited ................................................................................................................................27
2
Introduction
Fishers in the western United States are a cause of rising concern among researchers, environmental
organizations, and government agencies. Particularly vulnerable due to extreme population fragmentation
and habitat loss (Zielinski et al. 2005) the West Coast fishers are considered a “species of special
concern” by the California Department of Fish and Game (CaDFG) and a “sensitive species” by the U.S.
Forest Service (USFS). In 2004 the U.S. Fish and Wildlife Service (USFWS) ruled that listing this
population under the Endangered Species Act was “warranted but precluded” (USDI 2004).
The distribution of fishers throughout California, including population fragmentation and the isolation of
the southern Sierra population, is well documented (Zielinski et al. 2005, Lindstrand 2006). Their reliance
on the structural complexity typically associated with older conifer forests has been established (Truex et
al. 1998, Mazzoni 2002, Zielinski et al. 2004a), and the diet of Sierra Nevada fishers has been shown to
be radically different than that of fishers in other parts of the continent, and includes vegetation, fungi,
reptiles, and insects as well as more traditional mammalian prey (Zielinski et al. 1999, Zielinski and
Duncan 2004). Information on denning and foraging habitat, reproductive rates, dispersal patterns, and
sources of mortality is limited to nonexistent and additional research is needed to quantify population
vital rates. What little information does exist suggests that fisher habitat requirements are at odds with
many proposed fire management and fuel treatment options. Once vital rates are understood, it will be
possible to evaluate the impacts of management activities and to outline effective conservation strategies.
In order to fill the critical information gaps, the USFS is developing a long-term, comprehensive fisher
research program in the Kings River Project of the Sierra National Forest. Designed to build on past
research and to complement ongoing broad-scale monitoring efforts, the proposed project will use a
combination of traditional and innovative methods to provide critical autecological knowledge, determine
fisher population vital rates and habitat preferences, and examine how these rates vary in relation to
landscape heterogeneity and forest management. We intend to explore the use of non-invasive survey
methods; to compare their accuracy and efficiency to more traditional monitoring techniques with the
goal of reducing our reliance on invasive monitoring procedures in the future. Techniques such as
telemetry, camera trapping, and detector dog surveys each offer unique advantages, and combining them
with physiological and genetic analyses will greatly increase our understanding of fisher ecology and
habitat requirements. In addition, the project is intended to parallel the University of California Sierra
Nevada Adaptive Management Program (UC SNAMP) fisher project, facilitating a larger sample size of
individual animals and a collaborative regional research approach.
Understanding and interpreting the effects of landscape heterogeneity, change, and fragmentation on a
species of concern requires a systematic approach. First, species-habitat and community associations must
be understood. Requirements such as prey species, den sites, or escape cover must be carefully
documented. Second, a clear understanding of population vital rates and associated processes is needed.
Population parameters such as survival, reproduction, and dispersal dictate population growth rates, yet
for mustelids in particular they are poorly understood at the landscape scale (Lima and Zollner 1996,
Gough and Rushton 2000). These processes also vary widely according to environmental conditions and
some understanding of this natural variation is necessary to determine if a species has been negatively (or
positively) impacted by landscape change (Schlaepfer et al. 2002). Finally, once the above data are
available, spatially-explicit models can be developed and used to explore the relationships between fisher
demographics and habitat heterogeneity and/or connectivity. While direct experimentation, where the
researcher can randomly assign treatments, is a more robust approach to understanding the impacts of
landscape change, it is often impractical to execute such research at the landscape scale. Instead, a more
realistic approach is to use a combination of individual and population-level models to explore the
relationships between landscape heterogeneity, forest management, and population growth (Turner et al.
1995, Macdonald and Rushton 2003).
3
The Kings River Project Area is a particularly ideal site for this study in that it offers a unique opportunity
to directly assess fisher response to fuel management activities. Since 1993, when the Kings River
Administrative Study Area was set aside by USFS for experimental research, it has served as a testing
ground for management techniques. The area is currently scheduled for fuel reduction treatments to begin
in 2007/2008, providing us a rare chance to monitor fishers before, during, and after management
activities, on both treated and untreated sites. This research framework, termed ‘before-after/controlimpact’, is a powerful, well-established method to identify and quantify the effects of human activities on
wildlife. It will allow us to sort out positive, negative, and neutral aspects from among the many changes
that result from fuel management actions. This information can, in turn, be used to modify future
management activities as necessary to reduce any negative impacts on fishers as well as other old-growth
dependant species.
Fisher: Overview of Status and Research Needs
Status
Grinnell et al. (1937) described the distribution of fishers in California as a continuous arc from the Coast
Range eastward to the southern Cascades, then south throughout the Sierra Nevada. By 1942, however,
the fisher was described as “near extinction in California” (Hall 1942), and trapping was banned in 1946
(Lewis and Zielinski 1996). Despite this reprieve, fisher numbers continued to decline throughout the
latter half of the twentieth century (Zielinski et al. 1995). Schempf and White (1977) reported that fishers
were decreasing in the southern Sierras and “persisting at very low density” in the northern Sierras. By
1987, Gould (1987) concluded that fishers had disappeared in the northern Sierras. Today, fishers are
found in only three places along the West Coast: one small population in the southern Cascades, one
population along the California-Oregon border in the Coast and Siskiyou Ranges, and one in the southern
Sierra Nevada (Aubry and Lewis 2003).
The fragmented status of fisher populations has raised concerns among wildlife researchers and land
managers. Citing habitat fragmentation and loss as well as the continued decline and isolation of remnant
populations, the U.S. Fish and Wildlife Service ruled in 2004 that listing West Coast fisher populations
under the endangered species act was “warranted but precluded” (USDI 2004). In California, the
Department of Fish and Game (CaDFG) considers the fisher a “species of special concern” and the U.S.
Forest Service lists the fisher as a “sensitive species”.
The southern Sierra population is of particular concern due to its unique characteristics, isolation, and
small size. It is separated from the nearest source population by over 400 km and has the lowest genetic
diversity and allelic richness of any fisher population in western North America (Wisely et al. 2004),
suggesting severe isolation. Based on the best available data, Lamberson et al. (2000) estimated the
population at 100 to 400 animals and predicted population extinction in all but the most optimistic
scenarios.
Three concepts are of primary concern with respect to the conservation of fishers in the western United
States. First, there is very little autecological data available on western fisher populations. Adult female
survival rates are believed to be critical in maintaining population growth rates (Truex et al. 1998,
Lamberson et al. 2000), yet estimates of survival and reproductive rates are imprecise and based on small
samples. Information on dispersal and foraging habitat is nearly nonexistent, and very few natal dens have
been located in California. As a result, researchers are unable to predict the impact of management
activities on fisher population viability. Second, despite over 60 years of protection fishers have failed to
recolonize their historic range, indicating that some factor or combination of factors continues to severely
limit the population. Third, the information that does exist links fisher habitat with the same forest
4
20
4
0
4
8
0
2 0 K ilo m e t e r s
K i lo m e t e r s
Figure 1. Study area of the Kings River fisher research project showing the Sierra National Forest, the
Kings River Administrative Boundary (red), and the treatment (green) and control (hatched) management
units.
5
elements (dense canopy cover, multiple canopy layers, snags, logs) that indicate a high risk of
catastrophic wildfire (Truex and Zielinski 2005). The conflict between managing forest fuels to reduce
the risk of fire yet providing sufficient habitat to allow fishers to survive and reproduce is the heart of the
current management dilemma.
Habitat Associations
Historically, wildlife-habitat relationship studies have focused on identifying landscape elements or cover
types where animals are most commonly found. These areas are then defined as ‘good’ or ‘high quality’
habitat. However a major problem with this approach is that “by definition, habitat can remain the same
(at least as we typically measure it) while use of niche parameters by an animal within that habitat can
change” (Morrison et al. 2001). In order to develop predictive power, it is therefore necessary to go
beyond simple species-habitat associations and look at the actual resources and/or constraints (limiting
factors) that an animal experiences in any given habitat. Figure 2 represents a conceptual model of the
environmental factors that may influence fisher ecology, survival, and reproduction in the Sierra Nevada
Mountains.
In the western United States, fishers generally prefer dense canopy, late-successional coniferous forests
and use riparian areas and steep slopes disproportionately more than their availability (Aubry and
Houston 1992, Truex et al. 1998, Mazzoni 2002, Zielinski et al. 2004a,b, Zielinski et al. 2006). Evidence
suggests that the physical structure of the forest rather than the specific forest type is the important
consideration (Buskirk and Powell 1994), and some researchers have hypothesized that shrub or sapling
cover may provide the necessary overhead structure and be an acceptable substitute for older, decadent
forests (Powell 1993). For example, Lindstrand (2006) reported finding fishers in atypical habitat (second
growth forest and chaparral) around Shasta Lake in northern California. However, use of these atypical
Mature trees, time, agents of decay,
excavators
Dense canopy
Large trees/snags
Variable tree sizes
Prey habitat =
Foraging habitats
Cavities in trees, and logs, platforms
Vegetation in vicinity
of rest and den sites
Mammals, Birds,
Reptiles, Fungi, Insects
Fruit
Rest sites
and dens
Fire
Food
Inbreeding
depression
Human activities
Competitors:
e.g., Marten, Fox,
Spotted owl
Fisher
Predators
Mates
Exposed rest sites
Hazard
Resources
Deep snow
Sex ratio
Sex-specific habitat
Disease
Bobcat, Lion, Coyote,
Raptors, Humans
Rabies
Distemper
Escape cover
Predator habitat,
Other prey
Fisher population size
Incidence in other carnivores
Figure 2. Fisher Envirogram, adapted from Zielinski and Truex, 2006. Graphical description of environmental
factors, both biotic and abiotic, that have the potential to limit fisher populations. Factor effects become increasingly
indirect further outward from the center.
6
habitats may be limited to summer (Kelly 1977, Arthur et al. 1989), with winter avoidance being related
to snow accumulation (Powell 1993, Krohn et al. 1997), and it is unknown whether these habitats
contribute to the overall quality of a territory (Powell and Zielinski 1994). Also, use of atypical habitats is
difficult to interpret due to the fact that most surveys are conducted using baited stations, thereby possibly
drawing fisher into habitats they would not normally visit.
Most of the habitat use data that does exist comes from analyses of rest sites, structures that are used as
protection from predators and inclement weather, and as a way to regulate body temperature (Powell and
Zielinski 1994). Platforms and cavities in the largest trees or snags available are the most common
structure used (Truex et al. 1998, Mazzoni 2002, Weir and Harestad 2003, Zielinski et al. 2004a), though
fishers in the Sierras have also been observed resting in rock piles, logs, and stumps (Truex et al. 1998,
Mazzoni 2002). Typically, Sierra Nevada rest sites are selected in areas of dense, multi-layered canopy,
on steep slopes, and within 100m of water (Mazzoni 2002, Zielinski et al. 2004a, Zielinski et al. 2006),
features that contribute to cooler microclimates. Similar structures area also used as both natal and
maternal dens, though female fishers appear far more particular about the selection of natal den sites.
Typically, natal dens are located in large trees or snags in areas of dense canopies (Powell 1993, Powell
and Zielinski 1994, Truex et al. 1998), though maternal dens have also been found in mistletoe brooms,
logs, and other structures (Aubry and Raley 2002).
Very little information is available on either foraging or dispersal habitat. In California, fishers exploit a
diverse prey base including squirrels, woodrats, mice, marmots, mountain beavers, quail, grouse, insects,
false truffles, plant material, carrion, and lizards (Grinnell et al. 1937, Zielinski et al. 1999, Zielinski and
Duncan 2004). Due to this diversity as well as the difficulties associated with monitoring rapidly moving
animals, less attention has been placed on defining foraging habitat than on identifying rest or den sites.
Information that does exist, gleaned from track plate and telemetry studies, indicates that fishers spend
time in areas with large trees, high canopy cover, coarse woody debris, and near water (Weir and
Harestad 2003, Zielinski et al. 2004b). Similarly, we assume that good fisher habitat is adequate for
dispersal yet little relevant information is available. Large, open areas and areas lacking overhead cover
are avoided (Powell 1993) and may act as barriers to dispersal. This avoidance may be more significant
during the winter when fishers are dispersing because of higher snow depth in openings (Krohn et al.
1997) or because whatever brushy cover is available during other months is absent (Kelly 1977). Finally,
there is evidence of sex-specific habitat selection. In Connecticut, Kilpatrick and Rego (1994) reported
that while males used rest structures roughly according to availability, females selected smaller, more
secure cavities. In the Sierra Nevada, Zielinski et al. (2004a) found a similar pattern and speculated that
female fishers, being significantly smaller than males, placed more emphasis on security and thermal
protection. Male fishers tend to use a wider elevational range, and there is evidence that female fishers
may be more susceptible changes in landscape structure (S. Matthews pers. com.). The difference in size
may also lead to disparate dispersal success and use of foraging habitat.
Potential Limiting Factors
Disease - Fishers exhibit low incidence of disease, although diseases documented in fishers include
sarcoptic mange, Aleutian disease, leptospirosis, parvovirus, toxoplasmosis, and trichinosis (Powell 1993,
M. Gabriel pers. com.). An analysis of exposure and susceptibility is particularly critical given the
consideration of translocation as an option to reconnect the California fisher populations. For example, an
analysis of 65 fisher blood samples from northern California showed approximately 30% parvovirus
exposure rate, while Sierran fishers have no exposure (n=33), and thus limited immunity, to parvovirus
(M. Gabriel, pers. com.).
Predation - Although fishers are rarely killed by non-human predators in eastern North America (Powell
and Zielinski1994), mortality rates may be higher for western fisher populations (Heinemeyer and Jones
7
1994). Predators of California populations likely include coyotes (Canis latrans), bobcats, (Felis rufus)
mountain lions (Puma concolor), and large raptors (Truex et al. 1998). Intraspecific predation may also
occur (Heinemeyer and Jones 1994), and the risk of predation may be related to changes in habitat
(Powell 1993).
Human activities - Human activities, including trapping, logging, and recreation, contributed significantly
to the decline of fishers throughout the twentieth century (Powell and Zielinski 1994). While trapping has
been banned in California since 1946, the levels of poaching or incidental mortality are unknown and
even small increases in mortality rates may influence population dynamics (Powell and Zielinski 1994).
Other human activities such as road construction and suburban development may contribute to habitat
fragmentation as well as both direct and indirect mortality. Proximity to human activities has been shown
to cause increased chronic stress in Northern spotted owls (Strix occidentalis caurina), a factor linked to
reduced reproduction and survival (Wasser et al. 1997). While a recent review found few impacts of
research activities on mammals (Murray and Fuller 2000), use of non-invasive methods is becoming more
prevalent and these options would be desirable if effective and merit further development.
Competition: The impact of competitors on fishers is relatively unknown. They share resources with
species such as coyotes, bobcats, gray foxes, martens, goshawks, spotted owls, and weasels. Despite this
array of competitors, their agility and ability to pursue prey both into the trees and into dens sets them
apart (Powell 1993). Only marten are similarly capable, but fishers’ larger body size makes them the
dominant competitor. This asymmetrical competitive relationship appears to be mitigated by snow depth,
restricting fisher habitat use and providing marten an elevational refuge (Powell 1993, Krohn et al. 1997).
Male/female territories overlap, and intraspecific competition appears limited to intrasexual territory
defense.
Inbreeding depression - Habitat fragmentation may subdivide continuous populations and restrict gene
flow (Lande 1999), and the resulting small, isolated populations are more susceptible to the effects of
genetic drift and the expression of deleterious recessive alleles. In California, fishers currently occur in
two populations isolated by over 400 km, one occupying the Klamath and North Coast regions of
northwestern California and one occupying the Sierra Nevada south of and including Yosemite National
Park (Zielinski et al. 2006). Recent genetic analysis suggests that gene flow once occurred between fisher
populations in British Columbia, Washington, Oregon, and that California populations are now
genetically isolated (Drew et al. 2003). At present, Sierran fishers have the lowest level of genetic
diversity among western populations (Drew et al. 2003, Wisely et al. 2004).
Research needs
Numerous gaps exist in our understanding of fisher ecology in the southern Sierra Nevada. While it is
beyond the scope of this study to address all the gaps, the unprecedented scale and experimental control
offered by the Kings River Project will facilitate a better understanding of the cause and effect
relationship between fishers and their environment. Additionally, the proposed study is 2-3 times longer
than any previous work on fishers in the west (B. Zielinski pers. com.) and will therefore yield richer
information on vital rates, limiting factors, and habitat use. Five gaps in our current knowledge that can be
addressed by the combination of this and the SNAMP project include reproduction, sources/rates of
mortality, foraging habitat, dispersal, and the response of fishers to habitat heterogeneity.
Reproduction - Almost no information is available on fisher reproductive rates, including pregnancy rates,
birth rates, litter sizes, and kit survival in the western United States. Given the dramatic differences
between fisher habitat and behavior in the West and in other parts of their range, it is possible that
reproductive rates may differ significantly. Changes in landscape structure can impact any of the four
metrics listed above, and a decreases in any reproductive parameter can dramatically reduce population
8
growth rates. A better understanding of reproductive rates is necessary before the impacts of forest
management can be evaluated.
Sources and rates of mortality – Ecological models are only as good as the parameterization data
available, and currently very little information is available regarding sources and rates of mortality.
Annual survival estimates for Sierran fishers range from 0.83 (CI: 0.51-0.96) in the Sierra National Forest
(M. Jordan pers. com.) to 0.59 for females (CI: 0.25 – 0.92) and 0.79 for male (CI: 0.41 – 1.0) in the
Sequoia National Forest (Truex et al. 1998). In both cases, small sample sizes resulted in relatively wide
confidence intervals. Causes of mortality are only available for the Sequoia study, and 45% of those
mortalities were from unknown causes; prompt collection in rugged terrain is difficult and scavengers
often obscured the cause of death.
Foraging habitat – Due to the difficulties associated with monitoring fisher movements, the vast majority
of research programs have inferred foraging habitat quality from either track plate detections or rest site
locations. However track plate detections reflect large-scale presence/absence, not fine-scale selection,
and the assumption that high quality resting habitat also provides foraging opportunities is tenuous;
fishers may leave resting areas and find prey quickly in high quality foraging habitat, yet spend more time
searching in poorer quality habitat (Powell 1993, Buskirk and Powell 1994, Powell and Zielinski 1994).
Results of other studies of nocturnal, secretive carnivores have suggested that single diurnal locations are
insufficient to characterize habitat use and that movement patterns, search time, and travel time may be
more appropriate parameters (Comiskey et al. 2002, Dickson et al. 2005).
Dispersal - Very little is known regarding the dispersal patterns, success rates, and dispersal barriers for
fishers. This information is of critical concern due to the fishers’ inability to recolonize the central Sierra
Nevada despite over 60 years of protection. Landscape change, such as fragmentation due to roads or
development, may be a factor but there is too little information available to recommend conservation
strategies.
Influence of landscape heterogeneity on fisher vital rates - In order to recommend alterations to
management actions aimed at protecting fishers, it is necessary to understand how individual fishers
respond to landscape changes. The most feasible approach to this question, as proposed by the UC
SNAMP, is multiple large-scale case studies where fisher response to landscape heterogeneity can be
evaluated across landscapes via modeling techniques. These techniques also provide for the identification
of thresholds in landscape change, environmental conditions where a small change in habitat quality
results in a large change in fisher vital rates.
Study Objectives and Design
The proposed project is designed around three central objectives: 1) Collect sufficient ecological
information on the southern Sierra fisher population to document vital rates and limiting factors. 2)
Capitalize on the proposed Kings River fuel treatments in a quasi-experimental BACI (beforeafter/control-impact) research design to illuminate the impact of disturbances and forest management on
fishers. 3) Mimic the methodology of the UC SNAMP study to the extent that the two case studies can be
considered replicates of a larger, regional research program to clarify the influence of landscape
heterogeneity on fisher dispersal and population dynamics.
To accomplish these objectives and maximize the information available, the Kings River fisher program
will consist of three complementary research methods, spatially nested and conducted at two levels of
intensity. In effect, there will be two study areas corresponding to an area of high-intensity monitoring
(core study area) and low-intensity monitoring (peripheral study area). The core study area will consist of
five management units (MUs), three designated as treatment units (el_o_win_1, krew_prv_1, bear_fen_6)
9
and two designated as control units (exchequer, McKinley), averaging 1500 acres (6 km²) each (Fig. 1).
The total study area will encompass these five management units, the area between them, and as much of
the surrounding landscape necessary to monitor 20 animals. The actual territories used by the 20 animals
will define the total study area boundary, but it is expected to be approximately 200 km². The total study
area will be separated into 16 12km² hexagonal cells (Fig 3), representing the average home range size of
a female fisher in the Kings River area (Mazzoni 2002). Hexagonal cells will be placed to cover nearly all
of the Kings River Area that falls between 750 and 2700 meters in elevation, the optimal elevational
range for fishers in the southern Sierras (Zielinski et al. 2005).
Within the core study area, the three treatment MUs will undergo fuel reduction efforts between fall 2007
and spring 2009 according to the Kings River Project Final Environmental Impact Statement
(http://www.fs.fed.us/r5/sierra/projects/environassess/kingsriver/index.shtml). Each treatment MU is
comprised of a combination of ‘plantation’ areas (areas targeted for reforestation), matrix areas (areas
between plantation areas), and currently protected California Spotted Owl (CSO) habitat (Table 1).
Plantation areas occupy approximately ten percent of each management unit (not including rock outcrops,
meadows, or low-site quality areas) and are generally less than three acres in size each. Within these
areas, all trees larger than 30” dbh will remain. If no trees larger than 30” are present, four ‘legacy’ trees
larger than 24” will remain. Treatments for plantation areas will include a combination of planting,
thinning, and maintenance intended to insure tree regeneration.
In the matrix, tree removal will accentuate the uneven-aged and patchy character of the existing stands
and would provide additional growing space for remaining trees. Trees larger than 30” dbh will be
maintained. Trees between 11” dbh and 30” dbh will be thinned according to the inversed J-shaped curve.
Trees that remain by implementation of the KRP uneven-aged silvicultural strategy would be selected on
their ability to make use of growing space, protect nest trees, provide bank stability, reduce horizontal and
vertical fuel continuity, and restore historical species composition. Thinning will be conducted using a
combination of hand removal, mechanical thinning, and prescribed burning.
Designated CSO habitat, representing approximately 25% of each MU, will be thinned following the
2001 Sierra Nevada Forest Protection Act Record of Decision. Within Protected Activity Centers (PACs),
300 acre areas with the best available and occupied CSO habitat, trees less than 6” will be hand cut.
Outside the activity center but still within a PAC, thinning will be limited to trees less than 20” dbh.
Where plantations occur within a CSO PAC, trees less than 10” dbh will be thinned. Tree removal will
retain 50% canopy cover across the stand excluding rock and low site, and canopy reduction will be
limited to 20% of existing cover. Mechanical treatments will be limited to 75% of the stand in PACs.
Table 1. Proposed Kings River Project treatment and control management units, indicating total acreage
as well as acreage within each treatment type.
Treatment
CSO PAC habitat: thin less
than 6”
CSO AC habitat: thin less
than 10” (plantation)
CSO AC habitat: thin less
than 20” (non-plantation)
Uneven-aged management
strategy – plantation
Uneven-aged management
strategy – thin less than 30”
No harvest
Total acreage
Krew_prv_1
23
Management Unit
Bear_fen_1 El_o_win_1
109
18
Exchequer
0
McKinley
0
45
119
0
0
0
226
677
252
0
0
13
88
27
0
0
872
935
842
0
0
812
1991
277
2205
217
1357
1200
1200
1871
1871
10
Animals whose territories overlap with the core study area will be designated as focal animals. These
animals, estimated at 12-14 individuals, will be the target of intensive ‘movement path’ telemetry (see
below) in addition to diurnal triangulation and rest site/survival checks. Females will be closely
monitored during late winter and spring to document reproductive success. Peripheral animals, those
whose ranges do not intersect the treatment and control MUs, will be less intensively monitored, which
will include every-other-day survival checks, weekly rest site walk-ins, and equivalent den monitoring for
reproducing females.
Detector dog surveys will be conducted twice each year, in May/June and October. During each survey
period, each grid cell (described above) will be sampled three times by alternating dog/handler teams and
in a randomized order. Once all grid cells have been sampled three times, any part of the core study area
that has not been comprehensively surveyed will be identified by visually inspecting maps of survey GPS
tracklogs and surveyed. This approach will guarantee an initial, equal sampling effort across the entire
study area while guaranteeing sufficient data are collected within treatment and control units (core study
area) to support the BACI analysis as well as comparisons between telemetry and detector dog data.
Finally, the entire program will be nested within the larger USFS Region 5 Fisher Status and Trend
Monitoring Program (STMP). The STMP will act as a ‘safety net’ for dispersing animals. The STMP
consists of large-scale track plate and hair snare monitoring throughout the Sierras, including the genetic
identification of hair samples. Any animal marked and genetically identified by the Kings River Project
that subsequently leaves the total study area may be ‘recaptured’ by the STMP genetic analysis, providing
additional data on dispersal direction, distance, and success.
Overall, this nested design will help validate vital rate estimates by providing multiple, independent
sources of data. It will facilitate tests of non-invasive monitoring techniques and will allow us to explore
the use of detector dogs to generate spatial information (i.e. home range and/or habitat use). Finally, the
emphasis on focal animals will guarantee that sufficient data are generated to capitalize on the Kings
River treatments and the BACI design.
Specific Research Questions and Hypotheses
Research questions can be separated into two categories, those that rely on the implementation of the
Kings River treatments and those that do not. Within each category, questions have been ranked
according to our confidence in providing robust answers. Questions high on the list are relatively
straightforward; sufficient data should be available given the temporal and spatial scale of the proposed
study. Questions lower on the list represent riskier proposals; collecting sufficient data relies on
maintaining the maximum number of study animals, animal mortality, and other factors beyond the
researchers’ control. Despite the relative riskiness of these questions, they represent the next great hurdle
in our understanding of fisher ecology and the Kings River Project is the only currently active research
framework under which they can be addressed. Where appropriate, specific, testable hypotheses are
included. While questions in these two categories may appear mutually exclusive, in reality they are not
entirely so. Questions related to habitat use can be modeled using information on habitat use and
availability, regardless of whether the treatments are actually implemented. Applying treatments to the
landscape, however, will provide the true test of our hypotheses. An additional category of questions,
relating to methodology or comparison to other studies, has also been included.
1. Research questions unrelated to fuel treatment activities:
A) What is the population structure within the study area? (density, male/female & adult/juvenile
ratios)
B) What is the epidemiological history of the southern Sierra fisher population?
11
H1. Southern Sierra fishers will show a low exposure rate to parvovirus and other
pathogens.
C) What is the diet of Sierran fishers? Are there significant changes in primary prey items
between winter/spring and summer/fall seasons?
H1. Fisher scats will be comprised of a variety of prey items, including mammals, bird,
reptile, insect, vegetation, and fungus.
H2. Fisher diet will show significant seasonal changes related to food availability.
D) What are the causes of mortality and are these associated with landscape condition?
H1. Fisher mortality will be negatively associated with forest structural complexity.
H2. Fisher mortality will be negatively associated with the proportion of late-
successional conifer forest in an individual’s home range.
E) Do fishers show discernable patterns of within-territory habitat selection?
H1. Fishers spend a disproportionate amount of time in areas of older, more complex
forest, on steep slopes, and in riparian areas.
H2. Fisher scats will be collected in areas of older, more complex forest, on steep slopes,
and in riparian areas more often than in other areas.
H3. Fishers do not move randomly throughout their territories. Instead, they will move
between areas of high canopy cover and structural complexity, and will avoid open
areas and areas with increased human activity.
F) What is the population fecundity, including pregnancy rates, birth rates, litter size, and kit
survival?
G) Is food abundance or quality related to space use, survival, fecundity, or physiological stress?
H1. Variation in food quality and/or abundance, either annual or seasonal, will be related
too physiological stress.
H2. Survival and fecundity of fishers is higher in years with a high proportion of
high quality foods in their diet (mammals/birds vs. vegetation/insects).
H3. When fisher diets reflect a higher abundance of high quality foods, there will
be a higher degree of overlap in territories.
H4. Juvenile survival will be higher in years when dietary analysis reflects a
higher abundance of high quality foods.
H) Are southern Sierra fisher populations limited by predation, resources, dispersal, or mate
availability?
H1. Fisher population density will be most sensitive to changes in adult female mortality.
H2. Juvenile mortality will be strongly related to landscape condition and the related risk
of predation during the dispersal season.
H3. Reproductive rates will be most strongly related to female body condition and stress
levels for the previous year.
2. Research questions related to the Kings River Project and the associated BACI framework:
A) Following treatments, is there a change in the utilization distributions, number of animals,
individuals (turnover), or spatial population structure?
H1. Fuel treatment activities that result in reduced forest structure will result in reduced
use of treated areas by fishers.
H2. Following treatments, the spatial structure of the population will readjust as animals
shift territory boundaries in response to altered resources. This readjustment will not
occur in untreated areas.
B) Do fishers avoid areas that are mechanically thinned or burned? If so, how long after
treatment does this behavior persist?
H1. Fishers will avoid areas that have been treated and this behavior will persist
throughout the study.
12
C) Do landscape treatments result in increased physiological stress to fishers, as measured by
fecal hormone levels? If so, is this a temporary or permanent increase?
H1. Fisher scat samples in treated MUs will show an increase in fecal hormone
concentration following treatments.
H2. Any changes in hormone secretion rates associated with treatments will return to
baseline conditions prior to the end of the study.
D) Do fuel treatment activities result in changes to predator community composition or in the
activity levels of specific species?
H1. Activity levels of mid-sized mesocarnivores (coyotes and bobcats) will increase in
treated areas.
H2. Activity levels of larger carnivores (mountain lions) and competitors (marten,
raccoon, coyotes, bobcats) will decrease in treated areas.
3. Additional questions associated with validating and expanding upon non-invasive research methods
as well as comparisons between the Kings River and SNAMP fisher research programs.
A) Are population sizes and survival estimates generated from mark-recapture analysis of
detector dog surveys comparable to those generated by telemetry and camera surveys?
B) Can scat deposition patterns be used as a non-invasive surrogate for telemetry-based spatial
data?
C) What are the dominant community relationships that dictate fisher population dynamics? How
do the strengths of these interactions vary with landscape change and/or heterogeneity? (This
question can only be addressed in collaboration with the UC SNAMP program.)
H1. Southern Sierra fisher population dynamics are dictated more by intraspecific
than interspecific interactions.
H2. Fisher population dynamics are most strongly influenced by vegetation structural
complexity.
D) How do fisher population vital rates change following treatments? Is this related to the percent
of home range impacted? (This question can only be addressed in collaboration with the
UC SNAMP program.)
H1. The survival of fishers in treated areas will be negatively related to the percent of
their home range treated.
H2. The fecundity of female fishers in treated areas will be negatively related to the
percent of their home range treated.
13
A.
Dinky
Creek
Exchequer
Krew_prov_1
El_o_win_1
McKinley
Bear_fen_1
Blue
Canyon
B.
C.
0.5
7
0
7
0
0.5
1
1.5
2 Kilometers
14 Kilometers
Figure 3. Overall study design of the Kings River fisher research project. A. The location of treatment
(green) and control (shaded) wildlife management units within the two primary watersheds of the Kings
River Area, Dinky Creek and Blue Canyon. B. Estimated total study area, including 12 km² hexagon cells
representing an average female fishers’ home range. C. Web layout of 13 remote camera stations within a
hexagon cell.
14
Methods
Field Methodology
Trapping – As outlined in the UC SNAMP proposal (http://snamp.cnr.berkeley.edu/documents/), trapping
will begin at a central point in the Kings River area and will radiate outward within the elevation band
used by fishers (1000 – 2300 m) until 20 animals have been captured and collared. Trapping efforts will
be planned to assure that the study area will overlap with the proposed Kings River treatment sites as well
as equivalent control areas. Throughout the study, additional trapping will be conducted as needed to
maintain a sample of 20 collared animals or to capture and collar unmarked animals photographed within
the study area.
Fishers will be captured using Tomahawk live-traps equipped with 1’x1’x2’ cubbies (Wilbert 1992,
Seglund 1995). Traps will be placed at least 500m from main roads or other centers of human activity,
and will be camouflaged using a combination of burlap and natural material. Traps will be baited using a
combination of raw chicken and a commercial lure (Gusto, MN Trapline Products, Pennock, MN). Traps
will be checked daily and closed prior to severe weather events. No trapping will be conducted between
March 1 and May 31 in order to avoid capturing nursing females or young kits.
Handling - Captured fishers will be anesthetized using a combination of Ketamine hydrochloride and
Diazepam (200 mg Ketamine / 1 mg Diazepam). Anesthetized fishers will be equipped with ear tags, a
subcutaneous PIT tag (Biomark, Meridian, ID), and a radio telemetry collar (Advanced Telemetry
Systems, Isanti, MN). Radio collars will be painted with infrared reflective paint, white with a brown or
black topcoat, to facilitate the identification of marked individuals in subsequent non-invasive camera
surveys. Hair and tissue samples, obtained during insertion of ear tags, will be placed in desiccant and
saved for genetic analysis. Blood will be drawn from the femoral artery for disease and hormone analysis.
Disease analysis, including screening for over 20 common antigens such rabies, canine distemper, and
parvovirus, will be conducted by Integrated Ecological Research Center at the University of California
veterinary lab. Parasite samples will be collected for further disease analysis. Measurements taken will
include weight, body length, canine length and width, teat size, and footpad dimensions. Age will be
estimated based on tooth wear. Throughout handling, personnel will monitor temperature and respiration
and will be prepared to deal with unforeseen reactions. Upon completion of handling, anesthetized
animals will be placed in the trap cubby and allowed to recover. Animals will be released at the trap site
when they are deemed fully recovered.
Telemetry - Animals will be monitored using a combination of remote triangulation, walk-in, and
movement path analysis. All animals will be checked for mortality signals every other day. Each week at
least two locations will be generated using remote triangulation when the signal indicates the animal is
not moving. These locations will be based on a minimum of five bearings to more accurately represent the
animal’s location. At least once per week, a walk-in (following the signal until the rest/den site is located)
will be conducted. The rate of walk-ins will increase for females during late winter to locate maternal
dens and document reproductive activity.
Due to the difficulty locating and monitoring active fishers, foraging and movement-based data will be
collected on focal animals using movement-path techniques. Every day, a team of 3-4 technicians will
select target focal animals for monitoring. The team will proceed to locate a target animal, and will then
select monitoring points in order to create line-of-sight bearings and maximize accuracy. The team will
then disperse to assigned points and collect bearings at set intervals (i.e. every 5 minutes) for 2-3 hours
before moving to another target animal. These ‘movement bouts’ will be collected once a week for each
focal animal, and bouts will be distributed throughout the 24-hour period.
15
Aerial telemetry will be used to supplement ground efforts to locate missing animals and to help monitor
dispersing animals. If GPS technology becomes available during the course of the study, animals will be
recaptured and collars will be replaced. Telemetry error, for both ground and aerial efforts, will be
estimated by placing reference transmitters throughout the study area periodically, having technicians
estimate transmitter location, and calculating the straight line difference between actual and estimated
transmitter location.
Mortality - Collars will be equipped with mortality sensors and carcasses will be collected within 24
hours for necropsy if possible. Upon location of a carcass, personnel will carefully photograph the site
and search for predator sign (scat, tracks, etc). The carcass will be superficially inspected in situ for
evidence of predation such as blood, matted fur, or bite punctures. If canine punctures are found, the
distance between punctures will be measured, a photograph of the punctures and a measuring tape will be
taken, and punctures will be swabbed for predator saliva. Matted fur in the vicinity of bite marks that may
contain predator saliva will also be clipped and placed in paper envelopes. The carcass will then be
collected, put on ice, and transported to the UC Davis veterinary lab for comprehensive necropsy.
Reproduction - Female fishers will be closely monitored to determine pregnancy rates, birth rates, and kit
survival. Between 15 February and 31 March, daily walk-ins will be conducted to determine if a female
settles into a natal den. During this period and when snow conditions permit, females will be backtracked
to locate scat samples. Samples will be analyzed for the estrogen/progesterone ratios which, when
compared to samples collected from known female animals during other parts of the year, can indicate
pregnancy (Larson et al. 2003). When a natal den is located, a motion-activated infrared camera will be
placed to observe the den entrance to document litter size (when the kits are moved) and any predation
attempts. If deemed necessary and safe, the kits may be removed from the den and PIT tagged while the
mother is absent. Protocols developed by the Hoopa Valley Fisher Project (M. Higley pers com.) and
approved by the US Fish and Wildlife Service will be used. Any tree climbing will be done in compliance
with USFS regulations.
Vegetation/Landscape structure data collection – Vegetation and landscape characteristics will be
recorded in the immediate vicinity of all dens and rest sites located as well as where scats are collected.
Data collection methods will support comparisons with previous studies on fishers in the southern Sierra
Nevada e.g., Zielinski et al. 2004 a, b) When animals are located in trees or snags, we will record tree
species, height, dbh, decay/condition class, and structure (cavity vs. platform). When animals are located
in other structures, structure type and size will be recorded. In the immediate vicinity of rest/den sites, we
will record percent slope (using a clinometer), aspect, dominant California Wildlife Habitat Relationship
(CWHR) cover type, potential alternate rest sites, canopy closure (using a moosehorn), and distance to
water sources. During detector dog surveys a quick vegetation assessment will be performed at each scat
located, including canopy closure, stand type, and stand structure. The location of every fifth scat will be
flagged, and follow-up vegetation surveys documenting the habitat elements listed above will be
conducted. A combination of plot-level and remotely-sensed data will be used to characterize vegetative
conditions at the home range scale. Plot-level, Common Stand Exam data will be used to evaluate pre and
post-treatment conditions. CWHR classifications including habitat type, crown closure class, and tree size
class are available at both a 2.5 acre and a 100 meter minimum mapping unit (mmu). These data were last
updated by the California Department of Forestry and Fire Protection in 2005. Additional vegetation data
including vegetation type, size class, and density are available at the 2.5 acre mmu through the US Forest
Service Region 5. More detailed information on canopy closure in the area surrounding den and rest sites
can be digitized from either true color (2 meter resolution) or black and white (1 meter resolution)
orthoimagery, updated in 2004 and 2006.
Camera Surveys – Non-invasive, digital, passive infrared camera surveys will be used to identify
unmarked individuals to be targeted by trapping efforts and to quantify the overall carnivore community
16
(fisher predator and competitor activity levels). Each of the 15 12 km ² hexagon cells in the core study
area will be surveyed using 17 camera stations. The stations will be arrayed in a ‘trapping web’ design
(Parmenter et al. 1989): one camera in the center, six cameras located 500m from the center along six
radial arms, and another six located 1500m from the center along the same radial arms (Fig 3). Stations
will be baited with raw chicken placed in tube socks and nailed to a tree approximately 1m above the
ground. The sock protects the bait from insects and forces the animal to spend an additional length of time
acquiring the bait, increasing the opportunities for photos. Cameras will be placed on an adjacent tree
approximately 5m away, close enough to see if an animal is collared but with a wide enough field of view
to capture more wary visitors. An additional 4 cameras, placed along roads or trails and left unbaited, will
be used to document activity of animals unwilling to approach a baited station. Cameras will be checked
every 3 days and left in place for 15 days. Following the 15 day survey, cameras will be moved to new
locations and a new cell will be surveyed. Three grids will be surveyed at a time, resulting in a 45 day
survey period to cover the entire study area. Due to the high rate of ear tag loss by fishers (M. Jordan pers
comm., M. Higley pers comm.), any individual identification of marked fishers will utilize a combination
of size, location, pelage, and infrared reflective collar paint.
Detector Dog Surveys – Wildlife detector dogs, trained to locate fisher scat, will be used to supplement
population estimates and provide population-wide genetic and hormone data, data on foraging habitat,
and scat samples for dietary analysis. Surveys will be conducted twice annually starting in mid-May and
early October. Each hexagon cell (Fig 3) will be visited three times per survey. The first two visits will
start at a random location within the cell. Prior to the third visit, GPS tracklogs from the first two visits
will be reviewed. Any portion of treatment or control MUs not surveyed during the first two visits will be
targeted during the third visit. This approach will provide both a randomized survey design of the core
study area as well as comprehensive coverage of the treatment and control MUs. For each scat collected,
UTM coordinates, variables describing scat characteristics, placement, and general habitat characteristics
will be recorded. Every fifth scat location will be flagged for a return visit during which more intensive
vegetation measurement will be taken.
Two 1cm³ samples will be separated from each sample, one for nuclear (species-level) genetic analysis
and one for microsatellite (individual-level) genetic analysis. If sufficient material is left, the remaining
sample will be freeze-dried and sifted to separate fecal material and prey remains. Prey remains will be
sent to the USFS Redwood Sciences Lab (Arcata, CA) for identification. Fecal material will be sent to
the University of Washington’s Center for Conservation Biology (CCB) for hormone assays and
matching dog analysis. Matching dogs, a technique being developed at the CCB, involves using detector
dogs to separate scat samples by individual. While this is still an experimental approach, if successful and
verified by genetic analyses, it can substantially reduce the time and cost to determine individual identity.
Collected scat samples represent zero-error locations; at one time or another, the animal was at that
specific location. Whether these represent random locations or if a bias exists in where the samples are
placed is unknown. Utilization distributions, identical to those based on telemetry data, will be generated
using scat locations. These distributions will be compared to telemetry-based distributions to identify any
associated bias. If no variation between the distributions is detected, fine-scale habitat use analyses can be
conducted. If biases are detected, then habitat use will be interpreted accordingly, i.e. preferences for
defecating while foraging, while resting, in areas with extensive cover, etc. These scat-based utilization
distributions will also be used to interpret the impacts of fuel reduction efforts on fishers under the BACI
research framework.
Data Analysis
Analytical procedures can also be separated into three general categories. First, habitat use and vital rates
will be evaluated using relatively straightforward techniques (see below). These questions represent the
17
‘sure bet’ portion of the study, capitalizing on the length of the research and innovative methods now
available. Second, because fisher home ranges are relatively large in comparison to the proposed
treatment areas, each animal in a treated area will have some proportion of its range impacted. This
proportion represents the underlying process (habitat change) that may impact fisher behavior, and is
therefore an appropriate independent variable in a BACI response-gradient design (Stewart-Oaten et al.
1986, Morrison et al. 2001). This approach will facilitate comparison with the UC SNAMP project
because post-treatment divergence between impacted and un-impacted animals will be related to a
comparable measure (proportion of home range impacted) despite differences in treatment size. Third, the
influence of landscape heterogeneity and community composition on fisher population dynamics will be
investigated using a variety of modeling techniques including information theoretic (Burnham and
Anderson 2002) and hierarchical partitioning (Chevan and Sutherland 1991). This represents the ‘riskiest’
component of the project as these techniques require large amounts of data over a range of habitat
conditions. However, if successful it offers the opportunity to illuminate the relative importance of
various landscape and community variables to fisher population dynamics (Thompson and Gese 2007), to
perform simulated experiments that are unrealistic in practice (Turner 1995), and to predict the impacts of
future management decisions (Macdonald and Rushton 2003).
Question 1: A-F (Autecological and vital rate data)
1. Population density: density will be estimated from telemetry of marked animals using program
MARK (White and Burnham 1999). The population will be considered open. Due to the nonsystematic trapping efforts, parameter estimates will be developed based on a known fate,
staggered-entry, robust design. Another independent density estimate will be generated based on
genetic mark-recapture techniques using scats located by detector dogs.
2. Home Range: two types of home ranges will be calculated; 95% fixed kernel with 50% isopleths
due to the additional data generated on within-territory habitat use, and 100% minimum convex
polygon for comparison to past research (Zielinski et al. 2004b). To avoid the negative effects of
the spatial autocorrelation associated with movement paths, telemetry points will be weighted
based on time since last location (Katajisto and Moilanen 2006). Range generation will be limited
to animals for which a minimum of 20 points are collected. If sufficient data are collected, both
seasonal and annual ranges will be calculated.
3. Habitat Use: Fishers utilize large ranges and most likely orient those ranges over a range of areas
of varying quality (Macdonald and Rushton 2003). To capitalize on the variability in use, withinterritory habitat patches will be defined based on documented fisher habitat preferences,
including canopy closure, forest structural complexity, slope, and proximity to water sources.
Landscape pattern analysis (FRAGSTATS) will be used to document both the composition and
configuration of these habitats within territories. Within-territory habitat selection will be
evaluated using a combination of detector dog surveys (scat location) and telemetry data.
Movement paths will be compared to random walks using fine-scale cell-immigration modeling
(Tischendorf and Fahrig 2000). This approach incorporates both within- and between-patch
movement and is robust to small sample sizes. Care will be taken to assure that cell sizes are
appropriate given estimated telemetry error.
4. Reproduction: population fecundity will be evaluated based on the percentage of collared females
determined to be pregnant in February, the number of litters produced, and the mean number of
kits per female, both born and surviving to weaning. Pregnancy rates will be determined based on
scat samples collected either from trapping or during walk-ins on collared females when snow
conditions permit back-tracking from dens. Samples will be evaluated for estrogen/progesterone
concentrations and the ratio will be compared to animals of known pregnancy status. Hormone
ratio curves, indicating how ratios change throughout pregnancy, will be developed using a
combination of blood samples collected during trapping as well as from captive animals. Litter
18
size will be documented using remote cameras at den sites. Kit survival will be estimated using a
combination of remote cameras and genetic analysis.
5. Survival: age and sex-specific survival rates will be generated based on the fate of collared
animals. Collared animals will be monitored a minimum of 4 days per week to facilitate prompt
collection of carcasses, necropsy, and evaluation of cause of death. Additional survival estimates,
generated by Program MARK (White and Burnham 1999) and based on mark/recapture data, will
be compared to estimates based on known fate models. Individual survival probabilities,
necessary for the comparison of treated and untreated MUs, will be generated based on the
number of days an animal survives after first capture. These probabilities can be weighted
according to the animal’s approximate age (Karki 2003).
6. Diet: diet will be evaluated through laboratory analysis of collected scat samples. The
contribution of a particular food item will be quantified based on the percentage of scats in which
the item was found, or “percent occurrence” (Zielinski et al. 1999). This will facilitate the
identification of seasonal (winter/summer) or pre/post-treatment differences using a combination
of ANOVA and BACI analytical techniques (Morrison et al. 2001). Seasonal variation will be
quantified using standard univariate analyses. If available, additional data will be collected based
on gut analyses of recovered mortalities.
7. Disease: The epidemiological history of the southern Sierra fisher population will be evaluated
based on blood samples collected from captured individuals. In collaboration with Mourad
Gabriel and the University of California, Davis, Department of Medicine and Epidemiology,
samples will be analyzed for antibodies associated with: Canine Distemper Virus, Parvovirus,
Anaplasma phagocytophilum, Plague, West Nile Virus, Canine Herpesvirus, Canine Adenovirus,
Rocky Mountain Spotted Fever, Leptospirosis, Toxoplasmosis, Heartworm, Ehrlichia canis,
Lyme Disease. Antibody prevalance will be compared with fisher samples from Northern
California as well as other mesocarnivore samples from throughout California.
Question 1H (Limiting factors)
Population limiting factors are difficult to identify, often requiring a subjective analysis of ecological
and genetic information (Lande 1988). A more rigorous evaluation of potential limiting factors can be
conducted using a combination of population viability, sensitivity, and spatially-explicit demographic
modeling (Doak et al. 1994, Gaona et al. 1998). This approach is only feasible when long-term
demographic data are available. Therefore, modeling efforts will combine seven years of data from
the Kings River fisher project, data from previous Kings River research, as well and the best
availability data from other Sierra Nevada fisher research programs. If available, associative habitat
models currently under development at the Conservation Biology Institute will also be used for
analysis and the comparison of treated and untreated areas (CBI:
http://www.consbio.org/cbi/projects/fisher/index.htm).
Question 2A (Demographic changes following treatments)
Standard BACI analyses (Stewart-Oaten et. al. 1986) will be used to evaluate changes in the number
of animals and turnover rate following treatments. Changes in the population spatial structure will be
quantified by evaluating how an individual fisher’s range changes year-to-year (annual overlap). The
degree of change in both total range and core-use areas will be compared between treated and
untreated areas.
Question 2B (Significant avoidance of treated areas)
Behavioral changes associated with treatments will be evaluated using utilization distributions and a
combination of telemetry and detector dog data (Worton 1989). Changes in the utilization
distributions of black bears following habitat alteration have shown a rapid response (Mitchell and
Powell 2003) and should reflect an individual fisher’s response to treatment activities. Movement
between within-territory habitat patches will be quantified based on cell-immigration modeling
19
(Tischendorf and Fahrig 2000). This will facilitate an estimation of habitat connectivity in both
treated and untreated landscapes as well as quantifying any post-treatment change. Care will be taken
to assure that cell sizes are appropriate given estimated telemetry error. Changes in scat deposition
patterns will also be evaluated following treatments to determine if fisher use of within-territory
habitat elements changes.
Question 2C (Changes in physiological stress associated with Kings River treatments)
The impacts of changes in habitat quality may be subtle and the resulting effects may not be visible
for 3-5 years. For example, survival and/or rates may be small relative to the precision of our field
techniques. Or reduced resource availability may not be fatal or force an animal to abandon a home
range, but the associated chronic stress may increase susceptibility to disease or reduce reproductive
output (Munck et al. 1984, Wingfield and Farner 1993). During stress, animals produce a variety of
hormones which are subsequently excreted in feces. In particular, cortisol and corticosterone are often
used as indicators of the long-term stress associated with changes in habitat, social position, or food
availability (Wasser et al. 1997). The BACI experimental framework offers the opportunity to
monitor subtle shifts in habitat quality by comparing pre- and post-treatment secretion rates with
changes in habitat connectivity, resource availability, the spatial structure of the population, etc.
Detector dog surveys will be conducted within treatment areas and on adjacent untreated management
units. Two surveys will be conducted each year, resulting in pre-treatment, during treatment, and
post-treatment data. Hormone levels will be measured in collected scats and both temporal and spatial
change will be quantified. At least four post-treatment surveys will be conducted to see if any
increased levels return to normal or remain elevated. While little is known about hormone secretion
rates of fishers in natural, ‘unstressful’, conditions or their ability to habituate to stress, the use of a
relative measure between impacted and unimpacted animals will reduce the influence of this potential
confounding factor.
Question 2D (Changes in predator activity and relative abundance)
Pre and post-treatment predator activity levels will be compared using standard BACI analyses
(Stewart-Oaten et. al. 1986). Activity levels will be estimated using the number of photographs of
each species per survey period (Fedriani et al. 2000). Unbaited stations will be used to control for
habituation; reduced interest in baited stations in subsequent sampling sessions.
Question 3A (Population estimates from detector dog surveys)
Current mark/recapture models (i.e. Program MARK, White and Burnham 1999) incorporate a
number of assumptions associated with recapture rates, probability of detection, etc. The high
probability of detection by detector dogs (Long 2006) makes a number of these assumptions
unnecessary, yet the behavioral aspects (i.e. individual dog accuracy) mandate others (Cablk and
Heaton 2006). By concurrently monitoring fishers via both detector dogs and telemetry, we will be
able to compare and contrast the estimates generated by each method, to develop more appropriate
mark/recapture models, and to evaluate the utility and accuracy of detector dog-generated population
density and survival estimates.
Question 3B (Scat deposition patterns)
Currently, it unknown whether scat deposition patterns can be used to accurately estimate habitat use
or home range placement. Territorial animals often use latrines or scats deposited on prominent
landscape features to indicate boundaries (Gorman and Trowbridge 1989). Utilization distributions
will be generated based on the number of scats collected in different habitat types, and these will be
compared to similar distributions generated by telemetry data. Similarly, GIS analysis will be used to
create territory maps based on latrine and remnant scat locations, as well as the distribution of scats
from a single animal identified by the matching dog and/or genetic analysis. It is expected that
between 70% and 90% of scats found will be identified to individual using either of the two methods.
20
This spatial structure will be compared to one generated based on telemetry data, and any errors or
variation will be quantified.
Question 3C (Community relationships)
If sufficient data are available, and in collaboration with the UC SNAMP program, the relative
strength of species-habitat and fisher-competitor/predator relationships can be evaluated using a
combination of univariate analyses, hierarchical partitioning modeling (Chevan and Sutherland 1991),
and information theoretic modeling (Burnham and Anderson 2002). This approach calculates the
goodness of fit for a single dependant variable to all possible combinations of independent variables
in a multivariate dataset. The resulting variance is partitioned according to the relative contribution of
each independent variable (Thompson and Gese 2007). Fisher abundance, reproduction, and survival
will be compared with a suite of vegetation variables and predator/competitor abundance. The relative
influence of each community variable on fisher demographics can be quantified. If available, preybase data will be incorporated as well, however acquiring adequate prey-base data is currently beyond
the resources of this study. Used together, hierarchical partitioning and information theoretic
modeling can quantify the strength of community interactions and show how these strengths change
following disturbances
Question 3D (Changes in vital rates)
If sufficient data are available, and in collaboration with the UC SNAMP program, the impacts of
treatments on population vital rates will be evaluated using the BACI analytical framework (StewartOaten et al. 1986). Because fisher home ranges are relatively large in relation to the proposed
treatment areas, experimental units will be individual animals, those whose home ranges overlapped
with fuel treatment activities (impact) and those whose ranges did not (control). The proportion of
range impacted will be treated as an independent variable, and the relative response will be evaluated
using a response-gradient BACI design (Morrison et al. 2001).
Hair
Blood
Disease
Genetic
identification
Diet
Tissue
Reproductive
status
Scat
Stress hormone
analysis
Location /
habitat use
Figure 4. Outline of biological samples collected from Sierran fisher and their use/disposition.
Quality Assurance and Control
Past fisher research programs have been plagued by a number of difficulties including small sample sizes,
high variability in vital rates, and the invalid assumptions associated with most mark-recapture
techniques. The program we have designed is unique in several aspects and is designed to help overcome
these difficulties. First, while 20 animals is not an overwhelmingly large sample, we intend to monitor all
animals within the study area, not a sample. Therefore rates of survival, reproduction, and dispersal will
be actual parameters and not estimates.
Second, the project is designed to replicate the UC SNAMP fisher research project in the Fish Camp area
of the Sierra National Forest, effectively doubling the sample size and creating two replicates of a
21
regional study. Third, the project will run continuously for seven years, guaranteeing the monitoring of
several generations and facilitating a better understanding of population dynamics. Finally, we intend to
apply multiple methods, both invasive and noninvasive, in a nested study design. This will allow for the
comparison of estimates generated from different datasets and will allow us to avoid biases associated
with specific methods.
Standardization of protocols
Protocols for trapping and fitting fishers with radiocollars have been developed over more than seven
years of research on fishers in the Kings River Project study area. We will use trapping protocols
developed by Mark Jordan and approved by the USFS Pacific Southwest Research Station and the US
Fish and Wildlife Service. Radio telemetry protocols, including radio attachment and subsequent
monitoring, will be based on protocols developed by Mark Higley and Sean Matthews on the Hoopa
Valley Reservation and approved by the US Fish and Wildlife Service. New telemetry techniques will be
tested and used where possible and appropriate. Fix success and accuracy of GPS telemetry locations will
be tested as these methods are brought on line. Tests will examine the effects of canopy cover, satellite
view, elevation, aspect, slope, antennae orientation, and 3D vs. 2D fixes.
Training in field methods
Field assistants will receive training in trapping and handling of fishers, radio telemetry, camera
maintenance and operation, and proper data recording.
Oversight during data collection
Field crews will be coordinated by crew leaders with at least two years of similar supervisory experience.
Crew leaders will review data for completeness and immediately consult with field technicians to resolve
any problems or issues that arise. Issues will subsequently be reported to project supervisors who will
decide if additional action is warranted.
Data will be entered and checked on a daily basis in order to keep all crew members up-to-date and to
facilitate error checking. Geographic data will be roughly screened for gross transcription errors by
plotting and visual inspection. Pre-printed labels will be used with all biological samples to avoid
additional transcription errors.
Quantifying sources of error
Triangulation error for VHF telemetry applications will be measured using both test collars, both
stationary and moving. Technicians will periodically triangulate on test collars, and the difference
between the estimated and actual locations will be measured. Similarly, test collars will be located during
aerial flights and accuracy will be evaluated based on the linear distance between estimated and actual
locations. Prior to conducting a walk-in, telemetry teams will take bearings and estimate the animal’s
location. If the animal remains in that rest site and the site is subsequently located, the difference between
the estimated and actual location will be measured (Powell et al. 1996). Separate error estimates will be
generated for movement-based telemetry. Telemetry teams will collect sequential bearings on a collar
being carried by another technician over a period of two hours. Linear distance between the estimated
location and the actual location, based on a GPS carried by the mobile technician, will be calculated for
each sequential point. The linear movement path, created by connecting sequential locations, will be
buffered by the mean error, generating a polygon movement path.
Another potential source of bias and error is differences between detector dog/handler teams. This bias
can be separated into two categories; accuracy (what percentage of the scats located belong to the target
species) and efficacy (how often does the dog locate scats when they are known to be present). Accuracy
can be variable depending on the temperament, training, and personality of individual dogs, but can be
easily quantified based on nuclear genetic analysis identifying scats to the species level. Recent fisher
22
surveys have reported a variety of rates, ranging from 93% on the Hoopa Reservation to 46% on the
Sierra National Forest. On the Sierra National Forest, accuracy ranged from 67% for one dog/handler
team to 27% for the second. In particular, problems arose when one dog became cued into spotted skunks
as a target species and handlers were unable to differentiate scats in the field. To address this, future
surveys will emphasize ‘non-target training’, where dogs are trained off of non-target species known to be
in the area, and will include extensive training in the identification of fisher scats by field personnel.
Efficacy is more difficult to measure but can be evaluated several ways. First, periodically during each
detector dog survey period test grids will be run where known samples are placed prior to the survey and
in locations unknown to the handler. This approach has been used successfully to evaluate the efficacy of
dogs at locating desert tortoises (Cablk and Heaton 2006). Known samples will include both target and
non-target scats, reducing the likelihood that any associated human scent may bias the evaluation.
Second, the overlap between telemetry and detector dog surveys offers the possibility of similar,
uncontrolled trials. When dogs are used to survey grids where fishers are known to be recently active,
fisher presence will be assumed and the dogs’ ability to locate recent scats will indicate efficacy. Finally,
relative efficacy can be measured by having teams periodically revisit grids surveyed by the other team.
While this approach will not directly quantify efficacy, it will act as a safeguard if a particular team is
missing scats. In addition, team will be included as an explanatory variable in statistical models providing
additional control for this source of error.
Animal Care and Use
PSW will maintain a scientific collecting permit from the CaDFG. All personnel overseeing the handling
of fishers will complete the CaDFG course in proper wildlife handling and restraint techniques. In order
to assure compliance with Animal Welfare Act guidelines, we are in the process of obtaining a review and
approval by the UC Davis Animal Care and Use Committee.
Traps will be places in secure locations, away from human traffic and protected by natural elements such
as logs, rocks, or bark. The traps themselves are modified with a cubby that provides a protected area for
the animal. Traps will be checked daily. When traps are checked, non-target species will be released
immediately. Handling of fishers will be designed to minimize any stress or discomfort experienced by
the animals, including minimizing noise and movement. Animals will be processed and released at the
capture site. Dr. Louis Wright at the Fresno-Chaffee Zoo has agreed to accept any animal in need of
emergency medical care.
As the study progresses, a better understanding of the benefits and inherent biases of non-invasive
monitoring techniques will develop. If it is determined that non-invasive methods can generate sufficient
accurate data to answer the research questions, more invasive methods such as radio-telemetry will be
replaced with non-invasive methods.
Radio Telemetry and Communication
Radio telemetry collars will operate in the 164.000 MHz range, a frequency both within USFWS and
CDFG recommendations and significantly different than other, ongoing wildlife research programs in the
region. Standard USFS radios and the associated repeater network will be used for communication in the
course of this study. Additional communication between field crew members, particularly frequent
discussions associated with coordinating telemetry bearings, will be conducted using over-the-counter
Motorola radios.
Data Management and Archiving
Database management for a study of this complexity will be crucial to the success of the study. Trapping
data will be collected, at least initially, on hard copy forms. Original data forms will be stored at the San
Joaquin Experimental Range, with copies stored at the Fresno SNRC office. Data will be entered in a
23
Microsoft Access database. Telemetry, camera station, and detector dog survey data will be collected in
the field on a hand-held computer. Because each animal may be identified based on any one of several
variables (e.g., ear tag color combination, pit tag number, radio frequency, DNA signature), we will use
pit tag number as the unifying animal identification code in each dataset. In this way, we will be able to
link all data related to an individual animal. Should a marked animal lose its pit tag, all historical data will
be adjusted to reflect the new identification number. For example, location data useful in home range
delineation and habitat use will potentially be available from trapping data, telemetry data, detector dog
surveys, and camera surveys. Digital versions of all data will be stored on the SNRC server in Fresno and
on the PI’s computers, which will be backed up on an external hard drive three times per week. Due to
space limitations, digital photos will be archived on CD after each camera trapping grid is completed.
Data sharing with the UC SNAMP Fish Camp study will be coordinated as well as with the Region 5
Status and Trend Monitoring Program.
Tissue samples collected from trapping and handling will be stored in vials containing desiccant. Hair
samples will be placed in paper envelopes and allowed to dry. Both samples will then be frozen until sent
to Dr. Mike Schwartz at the USFS Rocky Mountain Research Station for genetic analysis. Blood samples
will be frozen and shipped overnight to the University of California, Department of Medicine and
Epidemiology, Davis, CA. Scat samples collected from trapping and handling will be frozen and stored at
the San Joaquin Experimental Range. Scat samples collected during detector dog surveys will be
separated into four samples as size permits: (1) approximately 1 cm³ fecal material will be removed and
frozen for archival purposes, (2) approximately 1cm³ fecal material will be removed and stored in DMSO
for species-level genetic analysis (detector dog accuracy analysis), (3) approximately 2 cm³ fecal material
will be removed and frozen for hormone analysis (4) the remaining fecal material will be frozen for either
matching dog or diet analysis. At the end of each detector dog survey period, scat samples will be shipped
to the University of Washington for storage and analysis. Archival samples will be stored in a designated
freezer at the San Joaquin Experimental Range.
Expected Products
The Kings River Sustainable Forest Ecosystem Project was initiated in the Sierra National Forest in 1994.
This collaborative adaptive management project was designed to investigate relationships between forest
ecosystems in the southern Sierra Nevada managed to mimic processes that shaped historic forests and an
array of ecosystem elements in a scientifically structured manner. Specifically, the effects of the proposed
forest management activities on wildlife species, including fishers, will be investigated. The project
provides a unique opportunity to meet existing information needs for conservation planning for fishers
because silvicultural treatments and prescribed fire will be implemented on a landscape scale within the
current limited distribution of fishers in the Sierra Nevada.
Results from this study will allow us to examine population trend and factors limiting fisher populations
in the southern Sierra Nevada and the potential to repopulate areas of the Sierra Nevada in which fishers
are currently absent. Forest management, by definition, results in changes to landscape heterogeneity and
therefore changes to habitat connectivity. Given their large spatial requirements, we assume that changes
in forest structure resulting from treatments will have some effect on habitat conditions; the question is
what is the overall effect, as manifested both spatially and temporally, on the fisher population. Therefore
improving our understanding of fisher ecology and identifying how fishers respond to these changes,
either through direct monitoring or modeling exercises, is necessary and will lead to more informed
management decisions and increased ability to satisfy NFMA obligations for viable, well-distributed
fisher populations.
Knowledge of within-territory habitat use has been identified as a key information gap. Past efforts to
delineate home ranges using the minimum convex polygon approach are drawn based on the outer
perimeter of locations, and within this area habitat preference is inferred from where an animal is most
24
often found (i.e. core use areas). However, the large territories maintained by animals such as fishers
invariably contain areas of varying suitability, and territories are established based on some degree of
composition and configuration (Macdonald and Rushton 2003). Also, a particular resource or area may be
critical for one aspect of survival but unused for another. In particular, data on foraging habitat are
lacking. Finally, time spent in a particular area or patch type may not be an appropriate measure of the
utility of that area: a fisher may find food quickly in high quality foraging habitat, then leave that area to
find a rest site (Powell 1993, Buskirk and Powell 1994, Powell and Zielinski 1994). Therefore, given the
need to understand the impacts of landscape heterogeneity on fisher, data on within-territory movements,
home-range composition, and resource configuration are critical.
Location of natal den sites, dens where kits are born and remain until they are old enough to be moved,
will provide much-needed information on this poorly-understood aspect of fisher reproduction and will
lead to protections described in the 2000 Sierra Nevada Forest Plan Amendment EIS. Knowledge is
particularly lacking on effects of landscape-scale treatments on fishers and their habitats. This study will
assess fisher response to ongoing and proposed management activities and provide information crucial to
understanding how we can maintain fisher population viability while reducing wildfire risk.
Results will be summarized each year but each succeeding year will provide greater confidence in
population vital rates. When a minimum of four years of data are collected, we will begin constructing
population and individual-based models.
Opportunities for Partnerships and Collaboration
PSW will collaborate with the University of California, Berkeley, the University of California, Davis, and
the Center for Conservation Biology at the University of Washington to accomplish the objectives of this
research. The project has received funding from the USFS Pacific Southwest Region through the UC
SNAMP initiative. Some work will fall on private land owned by Southern California Edison. They have
been very cooperative in the past and we will work closely with them to ensure access and appropriate
sharing of data and results upon completion of the study. We will work with CaDFG for permits and
wildlife handling training. Additional partnerships with the Fresno-Chaffee Zoo, an AZA accredited
facility, and CSU Fresno are being developed. We expect to hire and train many recent college graduates
over the course of the study while assisting on this project and provide opportunities for graduate student
research that will lead to the completion of post-graduate degrees.
External Communication and Coordination
The results of this study will be available to the Forest Service and all interested parties. We expect that
results of this research will represent a useful addition to the primary literature on the population ecology
of fishers. Results will be presented at professional conferences and workshops, published in peerreviewed scientific journals, and made available on the PSW Sierra Nevada Research Center web site.
Statistical Review
Pacific Southwest Research Station statisticians have been consulted and have provided a thorough
statistical review of the sampling design and proposed analytical methods described in this study plan.
Additional reviews and statistical consulting will be requested as necessary.
25
Budget, Staff, and Time Requirements
Category
Salaries and Benefits
1 GS-12 postdoc
2 GS-7 crew leaders
8 GS-5 technicians
2 summer interns
consultant
Rate
2007
$3015.00 / pp
$1500.00 / pp
$1191.00 / pp
$25/day
$1000/week
72360.00
60000.00
171504.00
6000.00
5000.00
314,864.00
78390.00
78000.00
247728.00
6000.00
0.00
410,118.00
100,000.00
100,000.00
2500.00
2500.00
8900.00
8900.00
111,400.00
111,400.00
13800.00
16500.00
4800.00
29000.00
2000.00
66100.00
21600.00
18000.00
7200.00
0.00
0.00
46800.00
5000.00
1500.00
5000.00
1500.00
1500.00
3200.00
5000.00
2000.00
2500.00
subtotal
3085.00
2345.00
5000.00
2000.00
4000.00
960.00
5000.00
22390.00
3500.00
17700.00
subtotal
18792.00
748.00
5400.00
1496.00
2395.00
198.00
2000.00
31029.00
5000.00
5000.00
552,283.00
597518.00
subtotal
Agreements
University of Washington
Detector dog surveys, species level
genetic & hormone analysis
Rock Mtn. Research Station
Individual level genetic analysis on tissue
and hair samples
UC Davis / IERC
Pathology tests on blood samples and
Necropsies
subtotal
Vehicles
4X4 pickup (3)
$600/mo per vehicle
2X4 pickup (3)
$500/mo per vehicle
SUV (1)
$600/mo per vehicle
ATV (3)
ATV trailer
subtotal
Travel
Services
2008 – 2013 (per year)
aerial telemetry
Supplies
Trapping supplies
Telemetry collars (11)
GPS collars (5)
Office Supplies
Survey supplies
Software
Miscellaneous supplies
Equipment
Remote cameras
GPS units (6)
USFS radios (4)
Handheld field computers (4)
Telemetry receivers (4)
Otter packs
Misc. equipment
Total
26
Health and Safety
Job Hazard Analyses (JHA) have been prepared for live trapping, mountain lions, rattlesnakes, Lyme
Disease, Hanta Virus, motorized vehicles, ATV use, and driving on forest roads and will be updated
annually. Additional JHAs will be prepared for winter driving, hypothermia, and working in winter
conditions. All JHAs will be reviewed, discussed, and signed by field crews. Appropriate precautions will
be taken to ensure the safety of field crews, including weekly ‘tailgate safety sessions’. Field assistants
handling fishers will obtain pre-exposure prophylactic immunization for rabies. All field assistants
driving government vehicles will receive drivers training necessary to obtain government driver’s
licenses. Safe mountain driving practices will be discussed and stressed.
NEPA Compliance
We are not aware of any aspect of this research that requires NEPA analysis. An Environmental Impact
Statement for the Kings River Project will fulfill NEPA requirements for the management treatments
applied by the Sierra National Forest.
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