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Susitna-Watana Hydroelectric Project Document
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Title:
Distribution, abundance, and habitat use by large carnivores study, Study
plan Section 10.8 : Final study plan SuWa 200
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Alaska Energy Authority
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Final study plan
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Series (ARLIS-assigned report number):
Susitna-Watana Hydroelectric Project document number 200
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Published by:
[Anchorage : Alaska Energy Authority, 2013]
Date published:
July 2013
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Study plan Section 10.8
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Pagination:
13 p.
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All reports in the Susitna-Watana Hydroelectric Project Document series include an ARLIS-
produced cover page and an ARLIS-assigned number for uniformity and citability. All reports
are posted online at http://www.arlis.org/resources/susitna-watana/
Susitna-Watana Hydroelectric Project
(FERC No. 14241)
Distribution, Abundance, and Habitat Use by Large
Carnivores Study
Study Plan Section 10.8
Final Study Plan
Alaska Energy Authority
July 2013
FINAL STUDY PLAN DISTRIBUTION, ABUNDANCE, AND HABITAT USE
BY LARGE CARNIVORES 10.8
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 10.8-1 July 2013
10.8. Distribution, Abundance, and Habitat Use by Large Carnivores
On December 14, 2012, Alaska Energy Authority (AEA) filed with the Federal Energy
Regulatory Commission (FERC or Commission) its Revised Study Plan (RSP), which included
58 individual study plans (AEA 2012). Section 10.8 of the RSP described the Distribution,
Abundance, and Habitat Use by Large Carnivore Study. The Large Carnivores Study is a two-
year (2013–2014) effort that combines (a) desktop anal yses of existing data on bears and wolves
from historical studies and recent and ongoing population-monitoring studies by the Alaska
Department of Fish and Game (ADF&G), with (b) new field sampling focused on bears using
riparian areas along spawning streams used by anadromous fish downstream from the proposed
dam. RSP 10.8 provided goals, objectives, and proposed methods for data collection regarding
large carnivores, including brown bears, black bears, and wolves.
On February 1, 2013, FERC staff issued its study plan determination (February 1 SPD) for 44 of
the 58 studies, approving 31 studies as filed and 13 with modifications. RSP Section 10.8 was
one of the 31studies approved with no modifications. As such, in finalizing and issuing Final
Study Plan Section 10.8, AEA has made no modifications to this study from its Revised Study
Plan.
10.8.1. General Description of the Proposed Study
The Large Carnivores Study is a two-year (2013–2014) effort that combines (a) desktop analyses
of existing data on bears and wolves from historical studies and recent and ongoing population-
monitoring studies by the Alaska Department of Fish and Game (ADF&G), with (b) new field
sampling focused on bears using riparian areas along spawning streams used by anadromous fish
downstream from the proposed dam. Some of the information needed for this study was acquired
as part of the preliminary studies begun in 2012 (AEA 2012).
Study Goal and Objectives
The goal of the study is to obtain sufficient information on three dominant predators and game
animals in the region—brown bear, black bear, and wolf—to use in evaluating Project-related
effects and identifying any appropriate protection, mitigation, or enhancement measures.
Project development will inundate or modify habitats used seasonally by brown bears, black
bears, and wolves. In addition, the associated development infrastructure and human activities in
the area during construction and operation could have indirect effects on bears and wolves
through changes in prey populations—including moose, caribou, and salmon—and changes in
disturbance and human hunting patterns. Data collected through this Large Carnivores Study will
provide information on the value of lost, created, or altered habitats for bears and wolves in the
study area.
Four primary objectives have been identified for this study:
1) Estimate the current populations of brown bears, black bears, and wolves in the study
area, using existing data from ADF&G.
2) Evaluate bear use of streams supporting spawning by anadromous fishes in habitats
downstream of the proposed dam that may be altered by the Project.
FINAL STUDY PLAN DISTRIBUTION, ABUNDANCE, AND HABITAT USE
BY LARGE CARNIVORES 10.8
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 10.8-2 July 2013
3) Describe the seasonal distribution of, and habitat use by, wolves in the study area using
existing data from ADF&G.
4) Synthesize historical and current data on bear movements and se asonal habitat use in the
study area, including the substantial body of data gathered by radio-tracking during the
1980s, as a continuation of the 2012 wildlife studies (AEA 2012).
10.8.2. Existing Information and Need for Additional Information
Existing information for bears and wolves is further detailed below. This study will supply
baseline data essential to assess potential Project-induced impacts and facilitate the evaluation of
protection, mitigation, and enhancement measures, as appropriate.
10.8.2.1. Bears
For the original Alaska Power Authority (APA) Susitna Hydroelectric Project in the 1980s,
Miller et al. (1997) estimated brown bear and black bear densities in the region using a mark–
resight technique. In the spring of 2000, 2001, and 2003, ADF&G used aerial line-transect
sampling (Becker 2001; Becker and Quang 2009) to estimate brown and black bear population
sizes in their 26,490-square-kilometer Talkeetna Study Area. That large area extended from the
East Fork of the Yentna River to the northeastern portion of the Susitna River drainage and
included most of the Project area. The portion of the reservoir inundation zone located upstream
from the mouth of Kosina Creek was not covered in that survey, however.
In spring 2003 and 2004, ADF&G conducted aerial line-transect sampling (Becker and Quang
2009) to estimate the population sizes of black and brown bears in a 21,528-square-kilometer
area encompassing Game Management Unit (GMU) Subunits 13A and 13B (GMU 13AB Study
Area). That area was bounded on the west and north by the Susitna River and extended from
Kosina Creek to the Gakona River. That survey area included the part of the reservoir inundation
zone that was not included in ADF&G’s Talkeetna Study Area. Brown bear and black bear
densities varied substantially across these large areas, showing a pronounced gradient from
higher densities in the west to much lower densities in the east. The density gradient was larger
for black bears than for brown bears (ADF&G, unpublished data).
The original APA Susitna Hydroelectric Project included studies of the population size and
density, demography, seasonal movements, dispersal, den locations, and predation rates on
moose calves by both brown and black bears from 1980 to 1985 (ABR 2011). No studi es of
bears were conducted downstream from Devils Canyon. The density of brown bears in the
upstream area was estimated to be 29.7 bears/1,000 square kilometers over an area of 12,127
square kilometers, which was defined as the area within the mean home -range diameter from the
Susitna River for brown bears (Miller 1987). Approximately 12 percent of the relocations (n =
1,720) of radio-collared brown bears occurred in the area that would have been inundated by the
APA Susitna Hydroelectric Project’s Low Watana reservoir; bears used that area twice as
frequently as expected both in the spring and for all months combined. This pattern of use was
evident for males and most females, but not for females accompanied by cubs of the year. Bears
spent the highest proportion of time in the Watana inundation zone during June, when they
foraged on south-facing slopes for roots, new vegetation, and overwintered berries, and preyed
on moose calves. Females with young cubs tended to stay at higher elevations, possibly to reduce
the risk of predation on cubs by male brown bears (Miller et al. 1997).
FINAL STUDY PLAN DISTRIBUTION, ABUNDANCE, AND HABITAT USE
BY LARGE CARNIVORES 10.8
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 10.8-3 July 2013
Brown bears preyed on moose calves from late May to early June, with predation rates declining
substantially by mid-July (Ballard et al. 1990). In addition to moose calves, the Susitna bear
population had access to salmon, which is unusual for brown bears in Interior Alaska. Bears,
especially males, moved to the Prairie Creek drainage, a tributary to the Talkeetna River located
southwest of Stephan Lake (between the Devils Canyon and Watana dam sites) during July and
early August to feed on spawning Chinook salmon (LGL 1985). Despite the availability of
protein-rich animal foods, berry production appeared to be a major factor limiting brown bear
productivity in the Susitna study area (LGL 1985). Miller (1987) estimated berry abundance and
canopy coverage within and above both impoundment zones proposed for the original APA
Susitna Hydroelectric Project. Horsetails (Equisetum spp.), an important spring food, were more
abundant outside the impoundment zones, but some sites with abundant horsetails would have
been inundated by the proposed reservoir (Helm and Mayer 1985). An ADF&G study of brown
bear movements and demography in GMU Subunit 13A is nearing conclusion; that study area is
located south of the proposed reservoir inundation zone for this Project.
The density of black bears in black bear habitat comprised of spruce forest and shrublands along
the Susitna River was estimated to be 90 bears/1,000 square kilometers in the 1980s (Miller
1987); that density estimate has not been updated since (Tobey 2008). Although black bears in
the upper basin occasionally ate moose calves, berries appeared to be their most important food
source (LGL 1985). Black bears spent most of their time in for ested areas along creek bottoms,
but moved out into adjacent shrublands during late summer as they foraged for berries,
particularly in the area between Tsusena and Deadman creeks (Miller 1987). In May and June,
52 percent and 46 percent, respectively, of all locations of radio-collared bears occurred in areas
that would be flooded by the proposed impoundment (Miller 1987).
The ADF&G management objective for brown bears in GMU 13 is to maintain a minimum
population of 350 animals (Tobey and Schwanke 2009). The management objective for black
bears in GMU 13 is to maintain the existing population of black bears with a sex structure that
will sustain a harvest of at least 60 percent males (Tobey 2008). Bears in GMU 13 are of interest
both as predators of caribou and moose and as important game species.
The Project could result in wildlife habitat loss and alteration, blockage of movements of
mammals, disturbance, and changes in human activity and access due to construction and
operation of the Project. Bears often pose management challenges for large development projects
in Alaska because of their attraction to areas of human activity and associated waste-handling
facilities.
10.8.2.2. Wolf
Most of GMU 13 (except Subunit 13D, south of the Glenn Highway), including the upper
Susitna River basin, currently is managed by ADF&G under a predator control program
instituted in response to the State’s intensive management law, passed in 1994. Since 2006, the
number of wolves in GMU 13 has been within the current management goal ran ge of 135–165
wolves (3.3–4.1 wolves/1,000 square kilometers) after the end of the hunting and trapping
seasons (Schwanke 2009). In neighboring GMU 14, the wolf population was estimated at 100–
130 animals in fall 2004 and 145–180 in fall 2007, well above the management objective of a
minimum population of 55 wolves (Peltier 2006, 2009). GMU 14 currently is not included in the
State’s predator control program.
FINAL STUDY PLAN DISTRIBUTION, ABUNDANCE, AND HABITAT USE
BY LARGE CARNIVORES 10.8
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 10.8-4 July 2013
The wolf study for the original APA Susitna Hydroelectric Project was conducted during 1981 –
1983 in the Nelchina and upper Susitna River basins, building on regional studies that began in
the 1970s (see ABR 2011 for details). That study provided data on pack size, territory
boundaries, den and rendezvous sites, and feeding habits, based on radio-tracking of collared
animals. During the study period, 13 different packs and a lone individual used areas in or
adjacent to the Devils Canyon and Watana impoundment zones proposed for the APA Susitna
Hydroelectric Project. Wolf packs used almost the entire upper Susitna basin, except areas above
4,000 feet elevation; elevational use varied seasonally, probably in response to availability of
prey species. In each year, 5–6 wolf packs used the areas that would have been inundated by the
APA Susitna Hydroelectric Project. Den and rendezvous sites usually were located on well-
drained knolls and hillsides with sandy, frost-free soils and mixed, semi-open stands of spruce,
aspen, and willow. The most important potential impact on wolves from the APA Susitna
Hydroelectric Project was predicted to be reduced winter availability of primary prey species
(moose and caribou) in the impoundment zones. In addition, habitat loss due to inundation and
facilities development would have caused wolves to adjust territory boundaries, potentially
resulting in intraspecific strife.
Wolves have been studied extensively in GMU 13 since the mid-1970s and are the subject of
ongoing surveys for ADF&G’s intensive management program. The number of wolves and
packs using the Project area currently is unknown, although it appears to be substantially lower
than during the original APA Susitna Hydroelectric Project studies because of current predator
control efforts in GMU 13 and 16. Research in recent years has focused on ADF&G’s Nelchina
study area in GMU Subunit 13A, located south of the proposed reservoir.
10.8.3. Study Area
GMU 13 is an intensive management area where predator control measures have been
implemented by the State of Alaska to increase caribou and moose populations. In GMU 13,
predator control measures have included land-and-shoot harvest of wolves and liberalized
regulations for the harvest of wolves and bears.
The study area for spatial modeling of bear density will consist of a large region that
encompasses the proposed Project area, including the reservoir inundation zone, the access and
transmission corridors, and other Project features (Figure 10.8-1). The study area includes the
entire area of GMU Subunit 13E plus parts of adjacent Subunits 13A, 16A, and 16B, to provide a
broad regional context for the analysis of bear densities. The subunits adjacent to Subunit 13E
were included in the previous ADF&G surveys (described below) that provided the source data
for the spatial density modeling that will be developed for this study, and can be included in the
modeling analysis with little additional effort.
Fieldwork in 2013 and 2014 will be limited to surveys of bear use of anadromous fish spawning
streams in the Middle Segment of the Susitna River and its tributaries downstream from the
proposed Watana dam site that contain spawning runs of anadromous fishes, as far downstream
as the confluence of the Susitna River and the Chulitna River, all of which are located within
GMU Subunit 13E.
No field studies are proposed for wolves. The wolf stud y will involve analysis of existing
ADF&G data from GMU Subunits 13E and 13A, and possibly from adjacent Subunits 14B, 16A,
and 20A, pending further consultation with ADF&G during study implementation.
FINAL STUDY PLAN DISTRIBUTION, ABUNDANCE, AND HABITAT USE
BY LARGE CARNIVORES 10.8
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 10.8-5 July 2013
10.8.4. Study Methods
10.8.4.1. Bears
10.8.4.1.1 Population Estimation
A multi-faceted approach will be used to address the need for current information on bears in the
Project area. Re-analysis of 1980s data and synthesis with current data from other previous or
ongoing ADF&G telemetry studies and other regional management studies will provide data on
bear populations, movements, and habitat use in the study area (AEA 2012a).
Population estimates can be obtained from existing data collected recently in ADF&G’s two
line-transect study areas (described above in Section 10.8.2.1) by using complex distance models
with a new gamma-like detection function (Becker, in prep.) that is consistent with point
independence models (Borchers et al. 2006). By themselves, however, these estimates will not
allow more detailed inference about the number of bears in areas potentially affected by the
Project. The addition of spatial line-transect modeling (Hedley and Buckland 2004) will allow
computation of estimates that are both more accurate and more precise. The analytical objective
is to obtain density estimates from specialized multiple-covariate, mark-resight distance models
(Becker, in prep.) along small transect sections. These estimates will then be fitted with a
detailed spatial model (Miller et al., in prep.) that incorporates potential explanatory variables
such as elevation, aspect, habitat, and east-west and north-south gradients to derive a spatially
explicit density model, from which sub-estimates can be obtained (e.g., parts of both bear survey
areas that may be affected by the Project). The spatial models of Hedley and Buckland (2004)
must be modified (Miller et al., in prep.) to work correctly with the more complex distance
models (Becker, in prep.) used to model the initial bear densities. The spatial model must be
robust because of the potential for nonlinearity between the spatial covariates and bear density
(Miller et al., in prep).
The analytical work will require writing a Geographic Information System (GIS) program to
subdivide the 1,238 35-kilometer-long transects from the Talkeetna Study Area and the 1,221
30-kilometer-long transects from the GMU 13AB Study Area into small (1-kilometer) segments
that retain all relevant geospatial information. This work will be performed by the ADF&G
Division of Wildlife Conservation. The next step is to develop an R-based program to fit a
spatial model to the two datasets and then to run this code on the datasets to obtain the
population estimates. This work will be done by Dr. David L. Miller, University of Rhode Island,
Department of Natural Resources Science, who will work on the analysis and report preparation
with Earl Becker, ADF&G Division of Wildlife Conservation.
10.8.4.1.2 Downstream Surveys
ADF&G has concluded that adequate data generally are available for brown bears and black
bears in the Project area to evaluate the potential impacts of the Project, but “information on
downstream use of habitat and the importance of salmon in bear diets in conjunction with
impacts to salmon would aid in identifying potential impacts to bears downstream of the dam”
(letter from M. Burch, ADF&G, to AEA dated November 22, 2011). ADF&G does not consider
bear dens to be “sensitive” locations, however, because they are seldom reused (letter from M.
Burch, ADF&G, to AEA, dated December 20, 2011).
FINAL STUDY PLAN DISTRIBUTION, ABUNDANCE, AND HABITAT USE
BY LARGE CARNIVORES 10.8
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 10.8-6 July 2013
A survey of bear use of fish-spawning streams in the Middle Segment of the Susitna River and
associated tributaries downstream from the proposed Watana dam site will be conducted to
assess the use of those resources by bears in the Project area. The surveys will use DNA analysis
from hair samples to quantify the minimum number of bears using the downstream area and will
use stable-isotope analysis of hair samples to characterize the diet of bears in the sampled area.
Hair-snag stations such as single-catch snares (Beier et al. 2005) will be deployed along salmon
spawning streams in the Susitna River drainage downstream from the dam site and upstream
from Talkeetna, extending up tributary drainages that support spawning runs of anadromous fish.
The size and design of the hair-snag sampling array will be based on the expected densities of
bears, logistical considerations for access to the area, and comparison with similar studies in
central Alaska, in consultation with ADF&G biologists.
DNA analysis of bear hair samples will provide information on the sex and species of bear, a
minimum estimate of the number of different individuals using the sampling area, and stable
isotope signatures. The isotopic signature will be used to classify the proportion of the diet made
up of salmon, terrestrial meat, or vegetation (Fortin et al. 2007). ADF&G experts will be
consulted by AEA during the sampling design and analysis phases of the downstream bear study.
Evaluation of berry resources in the reservoir inundation zone will be accomplished during the
concurrent mapping efforts for vegetation and wildlife habitats and for wetlands (Sections 11.5
and 11.7, respectively) to assess the distribution and abundance of berry plants as forage for
bears.
10.8.4.2. Wolf
ADF&G’s Division of Wildlife Conservation has expressed the opinion that ongoing monitoring
work will be sufficient (ADF&G memorandum to AEA; November 22, 2011), so no additional
field surveys are deemed necessary for the Project. Hence, desktop analyses of existing ADF&G
data will be used to meet the study objectives for wolves.
Historical reports from the original APA Susitna Hydroelectric Project study will be reviewed
and synthesized, where possible, with data from other recent and current monitoring by ADF&G
of wolves in GMU Subunits 13A, 13B, 13E, 14B, 16A, and 20A, as a continuation of AEA’s
wildlife studies (AEA 2012a), initiated in 2012. Mapping of wolf pack territories and movements
from existing ADF&G telemetry datasets will provide useful background information, although
delineation of current pack territories will not be possible without tracking collared individuals,
and the applicability of the available data to the study area needs to be evaluated. Although the
findings of the wolf study conducted for the original APA Susitna Hydroelectric Project program
remain relevant and could be used for the current Project analyses, the original telemetry data for
wolves are no longer available and therefore cannot be reanalyzed using newer geospatial
techniques.
10.8.5. Consistency with Generally Accepted Scientific Practice
Distance sampling using line transects surveyed from small airplanes (Becker and Quang 2009)
is the primary method currently employed by ADF&G to obtain regional estimates of bear
population density in southern Alaska. Mark–recapture analysis of genetic markers and stable
isotope analysis from hair samples have been widely used in recent years. Analyses of hair
FINAL STUDY PLAN DISTRIBUTION, ABUNDANCE, AND HABITAT USE
BY LARGE CARNIVORES 10.8
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 10.8-7 July 2013
samples to examine bear diets and population size have been used previously in Alaska (Fortin et
al. 2007; Gardner et al. 2010).
10.8.6. Schedule
This study is a multi-year effort (Table 10.8-1), part of which began in 2012; re-analysis and
synthesis of existing bear and wolf data gathered through 2011 is currently being c onducted
(AEA 2012a). Incorporation of new data and additional analyses will be conducted incrementally
as recent and current data are obtained from ADF&G databases. Field surveys of bear use of
salmon streams downstream from the proposed dam site will be conducted during mid to late
summer in 2013 and 2014 to coincide with the timing of spawning runs of salmon. Evaluation of
berry resources in the reservoir inundation zone will be accomplished during concurrent mapping
efforts for vegetation, wetlands, and wildlife habitats. Data analysis, QA/QC, and reporting will
be conducted in the fall and winter months after recent and current data are transferred from
ADF&G and fieldwork is completed in late summer. The Initial Study Report and Updated
Study Report will be completed within 1 and 2 years, respectively, after FERC’s Study Plan
Determination (i.e., February 1, 2013). Technical Workgroup meetings will be planned on a
quarterly basis in 2013 and 2014.
10.8.7. Relationship with Other Studies
As is depicted in Figure 10.8-2, the Large Carnivores Study will benefit from other sources of
information, including the Fish Distribution and Abundance in the Lower and Middle Susitna
River Study (Section 9.6), the Vegetation and Wildlife Habitat Mapping Study (Section 11.5),
and various ongoing ADF&G management projects not sponsored by AEA. The fish distribution
study will supplement the State’s Anadromous Waters Catalog by helping to identify fish
spawning areas downstream from the proposed dam, which will in turn define the sampling areas
for collection of hair samples from bears visiting those streams. The hair samples will provide
the material needed for DNA analyses to enumerate the minimum number of bears using the
streams and for stable isotope analyses to characterize their diets. These results then will be used
to assess potential impacts and to inform development of protection, mitigation, and
enhancement, as appropriate.
The Vegetation and Wildlife Habitat Mapping Study will provide the information needed to
evaluate berry abundance in the proposed reservoir inundation zone. These results will also be
used to assess potential impacts and to inform development of protection, mitigation, and
enhancement, as appropriate. The information on berry abundance will contribute to the
Evaluation of Wildlife Habitat Use (Section 10.19) to identify areas and habitats that are used
heavily by bears for foraging in late summer and early fall.
Existing data collected by ADF&G will be used to model the densities of brown bears and black
bears in the region in which the Project area is located, as well as for population analyses of the
wolf population in the Project area. Bear locations and numbers from two of ADF&G’s regional
line-transect surveys conducted within the last decade will be used for spatially explicit analysis
and modeling of bear densities in a larger study area that encompasses the Project area.
Similarly, the size of the wolf population and densities of wolves in the Project area will be
estimated using existing ADF&G data from recent and ongoing studies. Data from these analyses
will be used in the Evaluation of Wildlife Habitat Use (Section 10.19) to identify areas and
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Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 10.8-8 July 2013
habitats that are used heavily by bears and wolves, and that information will be used to assess
potential impacts and to evaluate PM&E measures, as appropriate.
The primary potential impacts on bears could be direct loss of habitat, changes in prey density
and distribution, changes in berry production, changes in human use and hunting effort, and
increased potential of mortality due to defense of life or property (DLP), or availability of
anthropogenic food sources. Impacts on bears will depend, in part, on the proposed plan to
control anthropogenic food sources. The primary potential impacts on wolves could be direct
loss of habitat, changes in prey distribution and density, disturbance, and changes in hunting
effort.
Telemetry data from the ADF&G will be used, in conjunction with bear survey data described
above, to identify important habitats and high-use sites for bears and wolves in the Project area.
Data on the distribution, abundance, movements, and habitat use by bears and wolves will be
used to assess Project impacts. During the impact assessment that will be conducted for the
FERC License Application in 2015, direct habitat loss can be estimated through geospatial
analysis by overlaying the reservoir, access and transmission corridors, and other Project
infrastructure on the Project habitat map (Section 10.19) to identify important habitats that would
be lost. Additional indirect habitat loss and avoidance effects can be similarly estimated by
applying various buffer distances, as determined from available information on anticipated
effects. Data from the bear DNA study can be used to estimate the number of animals that might
be affected at various high-use areas and to assess the dietary importance of those streams to the
bear population downstream of the Watana Dam. The predicted effects on bears and wolves from
this study will be useful for impact assessments for prey species, such as moose, caribou, and
Dall’s sheep. The Wildlife Harvest Analysis (Section 10.20) will provide baseline data for
evaluation of changes in harvest and other mortality that may result from improved access. Data
on the seasonal distribution, abundance, and movements of bears and wolves among habitats in
relation to the geographic extent and seasonal timing of various Project activities can be used to
identify any necessary protection, mitigation, or enhancement measures, as appropriate.
10.8.8. Level of Effort and Cost
Sightability of bears from aerial surveys over forests is low and the large Project area makes
direct observations from the ground problematic. Stable-isotope analysis of bear hair provides an
indirect estimate of the major components of bear diets without requiring capture and handling of
bears. Approximately one to two weeks of field time by a crew of two biologists will be required
in mid-summer to establish the hair-snag grid between the proposed dam site and Talkeetna. The
hair-snag stations will then be checked at weekly intervals during late summer, when use of the
streams by bears is expected to be highest. The seasonal timing of sampling visits may be
adjusted on the basis of results from fish surveys for the Project.
Collection of data on berry distribution and abundance in the reservoir impoundment zone will
be conducted during the vegetation and wetland field surveys (see Sections 11.5 and 11.7),
eliminating the need for separate field surveys.
The spatial modeling of bear density, which will be conducted in 2013 only, is estimated to cost
approximately $65,000.
The study cost of the large carnivore study (including bears and wolves) in 2013 is estimated at
approximately $200,000, including the bear density modeling. The cost of the large carnivore
FINAL STUDY PLAN DISTRIBUTION, ABUNDANCE, AND HABITAT USE
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Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 10.8-9 July 2013
study in 2014 is estimated to be less because the bear density modeling will not be included. The
total two-year cost of the overall study is estimated at approximately $325,000.
10.8.9. Literature Cited
ABR. 2011. Wildlife data-gap analysis for the proposed Susitna–Watana Hydroelectric Project.
Draft report, August 16, 2011. Report for the Alaska Energy Authority by ABR, Inc.—
Environmental Research and Services, Fairbanks, Alaska. 114 pp.
AEA. 2012. W-S1: Big-game movement and habitat use study for the Susitna–Watana
Hydroelectric Project, FERC Project No. 14241. Draft final version (March 21, 2012).
Alaska Energy Authority, Anchorage.
Ballard, W. B., S. D. Miller, and J. S. Whitman. 1990. Brown and black bear predat ion on moose
in southcentral Alaska. Alces 26: 1–8.
Becker, E. F. 2001. Brown bear line-transect technique development. Federal Aid in Wildlife
Restoration, Research Performance Report, 1 July 1999–30 June 2000. Grant W-27-3,
Study 4.30. Alaska Department of Fish and Game, Juneau.
Becker, E. F. (in prep.) Aerial distance sampling with unmodeled heterogeneity and a gamma-
like detection function.
Becker, E. F., and P. X. Quang. 2009. A gamma-shaped detection function for line-transect
surveys with mark-recapture and covariate data. Journal of Agricultural, Biological, and
Environmental Statistics 14: 207–223.
Beier, L. R., S. B. Lewis, R. W. Flynn, G. Pendleton, and T. V. Schumacher. 2005. A single-
catch snare to collect brown bear hair for genetic mark–recapture studies. Wildlife Society
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BY LARGE CARNIVORES 10.8
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 10.8-10 July 2013
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FINAL STUDY PLAN DISTRIBUTION, ABUNDANCE, AND HABITAT USE
BY LARGE CARNIVORES 10.8
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 10.8-11 July 2013
10.8.10. Tables
Table 10.8-1. Schedule for implementation of the Large Carnivore Study.
Activity
2012 2013 2014 2015
2 Q 3 Q 4 Q 1 Q 2 Q 3 Q 4 Q 1 Q 2 Q 3 Q 4 Q 1 Q
Acquisition and analysis of recent and
current data on bears and wolves from
ongoing ADF&G projects & databases
Spatial modeling of bear population density
by ADF&G, using existing data
Field surveys of bears along spawning
streams downstream from proposed dam
(hair sampling for DNA & stable isotope
analyses)
Evaluation of berry abundance in reservoir
inundation zone (from vegetation and
wildlife habitat mapping field surveys)
Data QA/QC and analyses
Initial Study Report Δ
Updated Study Report ▲
Legend:
Planned Activity
Follow-up activity (as needed)
Δ Initial Study Report
▲ Updated Study Report
FINAL STUDY PLAN DISTRIBUTION, ABUNDANCE, AND HABITAT USE
BY LARGE CARNIVORES 10.8
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 12 July 2013
10.8.11. Figures
Figure 10.8-1. Study area for large carnivores.
FINAL STUDY PLAN DISTRIBUTION, ABUNDANCE, AND HABITAT USE
BY LARGE CARNIVORES 10.8
Susitna-Watana Hydroelectric Project Alaska Energy Authority
FERC Project No. 14241 Page 13 July 2013
Fish & Aquatics Instream
Flow Study (Section 8.5)
and
Salmon Escapement
Study (Section 9.7)
ADF&G Management
Projects (non-AEA)
Identification of salmon
spawning areas
downstream from dam
2Q–2013 & 2Q–2014)
Bear locations &
numbers from previous
line-transect surveys
(2Q–2013)
Wolf locations &
numbers from previous
population surveys
(1Q–2013 & 1Q–2014)
STUDY INTERDEPENDENCIES FOR LARGE CARNIVORE STUDY
Hair sampling from
bears along
spawning streams
below dam
Spatial modeling
of bear densities
using existing
population data
Analysis of
existing data on
wolf population
size & density
Evaluation of Wildlife
Habitat Use
(Section 10.19)
Estimated wolf
population size &
density in study area
(3Q–2013 & 3Q–2014)
GIS mapping of bear
distribution & densities
in study area (4Q–
2013)
Stable isotope analysis to
characterize diets of
bears using streams
(4Q–2013 & 4Q–2014)
DNA analysis to quantify
minimum number of
bears using streams
(4Q–2013 & 4Q–2014)
Vegetation & Wildlife
Habitat Mapping Study
in the Upper & Middle
Susitna Basin
(Section 11.5)
Evaluation of berry
abundance in reservoir
inundation zone
(3Q–2013 & 3Q–2014)
Studies of Fish
Distribution & Abundance
in the Upper, Middle, &
Lower Susitna River
(Sections 9.5 & 9.6)
Figure 10.8-2. Study interdependencies for the large carnivore study.