HomeMy WebLinkAboutAPA405SUSITNA HYDROELECTRIC PROJECT
PHASE II ·PROGRESS REPORT
BIG GAME STUDIES
Volume I BIG GAME SUMMARY REPORT
ALASKA DEPARTMENT OF FISH AND GAME
Submitted to. the Alaska Power Authority
April 1983 Susltna File Copy
File # Y · .3 ·~
SUSITNA HYDROELECTRIC -PROJECT
PHASE I I PROGRESS REPORT
BIG GAME STUDIES
VOLUME I . BIG GAME SUMMARY REPORT
ALASKA DEPARTMENT OF FISH AND GAl'vlE
Submitted to the
Alaska Power Authority
April, 1983
PREFACE
In early 1980, the Alaska Department of Fish and Game contracted
with the Alaska Power Authority to collect information useful in
assessing the impacts of the proposed Susitna Hydroelectric
Project on moose, caribou, wolf, wolverine, black bear, brown
bear and Dall sheep.
The studies were broken into phases which conformed to the
anticipated licensing schedule. Phase I studies, January 1, 1980
to June 30, 1982, were intended to provide information needed to
support a FERC license application. This included general
studies of wildlife populations to determine how each species
used the area and identify potential impact mechanisms. Phase II
studies continued to provide additional information during the
anticipated 2 to 3 year period between application and final FERC
approval of the license. Belukha whales were added to the
species being studied. During Phase I I, we are narrowing the
focus of our studies to evaluate specific impact mechanisms,
quantify impacts and evaluate mitigation measures.
This is the first annual report of ongoing Phase II studies. In
some cases, objectives of Phase I were continued to provide a
more complete data base. Therefore, this report is not intended
as a complete . assessment of the impacts -of the Susi tna Hydro-
electric Project on the selected wildlife species.
The information and conclusions contained in these reports are
incomplete and preliminary in nature and subject to change with
further study. Therefore, information contained in these reports
is not to be quoted or used in any publication Without the
written permission of the authors.
The reports are organized into the following 9 volumes:
Volume I.
Volume II.
Volume III.
Volume IV.
Volume V.
Volume VI.
Volume VII.
Volume VI ri.
Volume IX.
Big Game Summary Report
Moose -Downstream
Moose -Upstream
Caribou
Wolf
Black Bear and Brown Bear
Wolverine
Dall Sheep
Belukha Whale
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TABLE OF CONTENTS
Downstream Moose
by R.Modafferi ·1
Upstream Moose
by W.Ballard,J.S.Whitman,N.G.Tankersley,
L.D.Aumiller and P.Hessing 6
Caribou
by K.W.Pi tche r 12
Wolf
by W.B.Ballard,J.S.Whitman,L.D.Aumiller
and P.Hessing 19
Black Bears and Brown Bears
by S.D.Miller 23
Wolverine
-by J.S.Whitman and W.B.Ballard 27
Dall Sheep
by N.G.Tankersley 30
Belukha Whale
by D.G.Calkins 35
Literature Cited 38
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DOWNSTREAM MOOSE
Obj ectives of thi s study were to determine the probable nature
and approximate magnitude of impacts of the proposed Susi tna
Ri ver hydroelectric proj ect on moose (Alees alees gigas Miller)
in areas along the Susitna River downstream from the prospective
Devil Canyon dam site to Cook Inlet.To accompli sh this obj ec-
ti ve one must thoroughly understand how moose depend on flood-
plain habitats along the Susitna River.Only then,will one be
able to assess the relative importance of various floodplain
characteristics to moose and integrate those findings with hypo-
thetical post-project conditions to fully evaluate project
impacts on subpopulations of moose.This report is primarily
based on data gathered between 15 October 1982 and 15 October
1983 but also includes pertinent findings from the Phase I study
final report (Modafferi 1982).
Data on patterns of movement,habitat use,productivity,survival
and identity of subpopulations for moose ecologically affiliated
with the Susitna River were primarily synthesized from 2178 radio
relocations up to 15 October 1982 of 57 moose captured and
radio-collared in floodplain habitats along the Susi tna River
between Devil Canyon and Cook Inlet (Fig.1).Radio-collared
moose were relocated at about biweekly intervals through 16 March
1981 and about 10-day intervals from that time through 15 October
1982.Thi s schedule provided 7,10,12,7,7 relocation sites
for most individuals monitored during the winter (1 January thru
28 February),caiving (10 May thru 17 June),summer (1 July thru
31 August),"hunting season"(1 September thru 30 September)and
breeding (14 September thru 15 October)periods,respectively.
Most data collected from radio-collared moose were analyzed
relative to these periods in the life history of moose.Effects
of sex,subpopulation and year factors were considered in inter-
pretive analyses.Radio-relocations dated outside of these
periods were grouped wi thin spring,summer,autumn.and post-
breeding transi tory intervals.
To assess magnitude of seasonal and regional moose use of flood-
plain habitats along the Susitna River from Cook Inlet to Devil
Canyon,radio-relocation data were integrated with information
collected on 6 and 7 aerial censuses for moose conducted between
9 December 1981 and 12 April 1982 and between 29 October 1982 and
22 February 1983,respectively.
Data from river censuses,in turn provided additional and inde-
pendent information on productivity/survival of moose which
winter in Susi tna River floodplain habitats.In these interpre-
tive analyses,sex,seasonal period and subpopulation categories
were considered.
Some individual moose were found to range mostly within Susitna
River floodplain habitats,other individual moose only used those
habi tats during the winter and/or more frequently during the
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Figure 1.Polygon encompaaaing 2178 relocation polnta for 10 mooae
radio-collared 17 April.1980.29 moose radio-collared 10-12 March.
1981 and 17 moo.e radio-collared 28 February -10 March.1982 along
the Sua Una River between Devil Canyon and C·ook Inlet.Alaak.and monitored
through 20 October.1982.(Inclusive area =8938 km2 )
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calving period,and other moose used floodplain habitats during
one of those periods and also traversed riparian areas when
moving from one range to another.Though most radio-collared
moose used the Susitna River primarily as a winter range between
January through April,about 16 percent of the radio-collared
moose frequented floodplain habitats in extensively islanded
areas throughout the year.For the second consecutive year of
study,radio-collared female moose north of Talkeetna sought
island and riparian habitats along the Susi tna River near the
time of calving.The later movement pattern was attributable to
availabili ty of nutri tous food and/or avoidance of predators.
Preliminary findings from radio-collared moose that winter in the
Susitna River floodplain resulted in 3 subpopulation classifica-
tions for individuals with breeding ranges centered in .areas:1)
to the north of Talkeetna,2)to the ,south of Talkeetna and on
the eastside of the Susi tna River and 3)to the south of Tal-
keetna and not in eastside areas.Observations of movement pat-
terns from more recently radio-collared moose suggest that two
other discrete subpopulations of moose which winter in the
Susitna River floodplain frequent the Little Susitna River/
Waailla area or the Mt;Susitna/Beluga Lake area at other sea-
sonal periods.
Radio-collared moose north of Talkeetna seldom ranged farther
than 8 km from riparian habitats;moose south of Talkeetna com-
monly ranged farther than 8 km from the Susitna River and
relocations up to 40 km from floodplain areas were not uncommon
for the later area.Though moose north of Talkeetna did not
range far from riparian habitats,.some did travel greater dis-
tances,parallel to the river,during each annual cycle.
Large variation was observed in movements and sizes of ranges for
radio-collared moose.Males generally ranged over greater dis-
tances than females.Many individual moose were found to range·
over larger areas durin~the second year of study.Similar but
smaller increases in range size were observed after 2 years of
study.Most but not all radio-collared moose returned to flood-
plain habitats each winter.One male did not return to Susi tna
River riparian habi tats for two consecutive winter periods.
Since magnitude of use of winter .range by Susi tna River Valley
subpopulations of moose is partly related to severity of climatic
conditions,findings presented in this report must be considered
as preliminary since sampling occurred and data were accumulated
during the relatively mild or average winters between 1979 and
1983.The later winter,which was characterized by large amounts
of snowfall through December and·was subsequently followed by
mild conditions and recession of snowcover provided some informa-
tion on weather related variations in behavior of moose and sub-
stantiated importance of this concern.
In the winter of 1981-82,a maximum of 369 moose were observed in
6 censuses of floodplain habitats along the Susitna River between
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Cook Inlet and Devil Canyon.A max~mum of 934 moose were ob-
served in 7 similar censuses conducted in the winter of 1982-83.
For the later winter,densities of moose greater than four per
km 2 of surface area were calculated for moose occupying flood-
plain habitats between the Yentna River and Cook Inlet in late
December.Overall observations indicated unequal distribution of
moose wi thin and between four geographic zones of the Susi tna
River.Within and between year variation in moose use of flood-
plain habi tats were associated wi th winter weather conditions.
Movements and distribution of radio-collared moose substantiated
that impacts to moose which seasonally use Susitna River flood-
plain habitats may ultimately be realized at great distances from
the Susitna River.In addition,each subpopulation of moose may
be vulnerable to different types of impacts.Similarly,mi tiga-
tion measures need not be limited to floodplain areas to be
effective,but may have to be specific for a particular sub-
population of moose.
Ninety-seven percent of the radio-collared female moose were
known to produce young in 1982;of them 59 percent produced
twins.Calf production in 1982 appeared greater than in 1981
after parturition,but by November ratios of calves per female
were similar for both years.Early winter weather conditions
were more severe·in 1982 than in 1981 and may account for the
decrease in calf survival observed in 1982.
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Moose in subuni ts
and sustenance for
from urban areas.
Susitna River north
people (mostly local
14B and 16A provide recreational opportunity
large numbers of hunters,many of which are
Subpopulations of moose in areas along the
of Talkeetna provide for significantly fewer
residents).
Mortali ty of moose recorded during the study was attributed to
hunting (on male and female moose),accidents associated with the·
Susitna River such as slipping on icc,drowning,perhaps on ice
or log jams during high water,and predation by brown bears.
Data indicated that males sustained higher rates of hunting mor-
tality and females experienced higher rates of non-hunting mor-
tality.
Moose winter use of sites where vegetative associations have been
al tered to more seral communi ties by acti vi ties of humans was
documented.During the winters of 1981-82 and 1982-83,it was
not uncommon to observe 40-60 moose in each of several sub-climax
sites about 3 km 2 in size.Because of the potential for habitat
rehabili tation as a mitigation option,it was recommended that
research studies designed to more fully understand the inter-
relationships between rehabilitated habitat and ecology of moose
in the lower Susi tna River Valley be initiated.
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Limi tations of sampling methods and present samples and their
relationship to differential behavior and winter weather condi-
tions were discussed.It was proposed that more radio-collared
moose,particularly males,need to be studied north of Talkeetna.
It was also suggested additional males be radio-collared and
monitored in other areas further downstream.The need for a con-
tingency plan designed to study all subpopulations of moose
during a severe winter,was reiterated.
Potential Major Impact Mechanisms and Associated Effects
Altered Seasonal River Flow Patterns and Loss of Annual Variation
in River Flow:soil erosion and deposition,inundation,
drought,ice jams,ice scouring (influence through destruc-
tion of vegetation and influence on main channel erosion and
redistribution of soil),fertilizing effects of inorganic
and/or organic nutrient loads,water or ice surface area,
redistribution of debris,terrestrial floodplain surface
area,floods,effects on beavers,bears or other subpopula-
tions of moose,composition,distribution and/or abundance
of plant species or plant communi ties.
Altered Water Temperature:ice fog/fog (physical,physiological,
visual,insolation and insulation);frosting of vegetation;
plant phenology;composition,distribution and/or abundance
of plant species or communi ties;ice scouring;ice jams;
open water in winter.
Alteration of Habitat:.transmission corridors,railway
vehicle rights of way;proj ect facilities,attractant
predators and conspecific competitors.
and
for
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Increased Access:transmission corridors;railway and vehicle
rights of way;winter boating.
Human Encroachment:construction and maintenance
hunters;visitors;recreators.
employees;
Increased Railway and Vehicular Traffic:disturbance,inter-
ference with movement,direct mortali ty.
Impoundment:inundation displaces predators and conspecific
competitors.
Altered Turbidity:composition,distribution and/or abundance of
aquatic plant species.
Salt Water Encroachment at Cook Inlet:composition,distribution
and/or abundance of aquatic and riparian plant species.
Altered Ecosystem:secondary and tertiary effects from impacts
on plant and other wildlife species as salmon,beaver,
bears,wolves and other subpopulations of moose.
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UPSTREAM MOOSE
Phase I moose studies (Ballard et al.1981;1982)were directed
at determining how moose use the area in and around the two
proposed impoundments,determining the approximate number of
moose using the area,and identifying potential impact mecha-
nisms.Phase II moose studies were designed to provide refine-
ment of the information gathered during Phase I studies.The
principal objectives of Phase II studies are as follows:
(1)To delineate a -zone of impact of the Susitna Hydroelectric
Proj ect on moose.
(2)To determine the number of moose using the zone of impact
and habitat which will be altered by construction of the
Susitna Hydroelectric Project during winter and early
spring.
(3)To determine changes in moose use of an area before and
after a prescribed burn.
(4)To evaluate moose use of potential mitigation lands.
(5)To develop a habitat-based assessment of the current value
of lands that will be lost or altered to moose.
This report updates some of the findings presented in the Final
Phase I report (Ballard et ale 1982)wi th additional data col-
lected from mid-August 1981 to early June 1982.
Preliminary analyses of movements of 10 adult cow moose radio-
collared in a proposed experimental burn area near the Alphabet
Hill revealed the presence of 3 subpopulations occupying the
area--2 wintering and 1 resident.From an intensive aerial·
census of the proposed burn and adjacent area during March 1982,
an estimated 279 moose occupied the 47,000 acres.
In fall 1982,22 adult radio-collared moose wi thin the Susi tna
Hydroelectric Study area were recaptured and recollared in an
effort to continue movement and habitat use studies during
phase I I.Home range sizes and movements of moose during the
reporting period were presented.During 1982,20 radio-collared
moose crossed the Susitna River in the vicinity of the impound-
ments a minimum of 42 occasions.Forty-nine percent of the
crossings were initiated during the month of January,February,
May and September.
Based upon locations of radio-collared moose which utilize the
impoundment~boundaries of impact zones were delineated.Zones
were classified as primary,secondary,and tertiary.The primary
zone included radio-collared moose which would be directly
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impacted by the project,while the secondary zone was comprised
of moose which overlapped home ranges of moose occupying the
primary zone.Population estimates ranged from approximately
1,900 to 2,600 moose which could be directly impacted by the
proj ect.Moose occupied the impoundment areas more during the
months of March-May than other time periods.Two hundred and
ninety moose were estimated to inhabit the Watana impoundment
area from an aerial census on 25 March 1982.
Habitat use of radio-collared moose was assessed by overlapping
moose locations on preliminary vegetation maps.In relation to
availability,moose preferred woodland black spruce,open black
spruce,closed mixed forest,and woodland white spruce types.
Lakes,rock,sedge-grass tundra,sedge-shrub tundra and mat-
cushion tundra were not preferred.
For the Watana impoundment area on a year-round basis,elevations
ranging from 2001-2200 and 2401-3000 ft.were used more by
radio-collared moose while elevations ranging from 1201-1400 and
in excess of 3200 ft.were used significantly less,in relation
to availability.During winter and spring,elevations ranging
from 1601-2000 and 2201-2800 ft.were used more than expected.·
Use of slopes and aspects were not random.
During the reporting period a moose population dynamics model was
developed and tested in an effort to predict population trends'
under preproject conditions.Components of the preliminary model
are presented and discussed.Eventually the model will be used
to test hypotheses concerning the impacts of Susitna Hydro-
electric development on moose.
Impact Mechani sms
Table 1 summarizes the major structural features associated with
the construction and operation of the Susitna Hydroelectric Pro-
ject and a description of their potential impact on moose.In an
effort to assess the effeGts of these impacts on moose,they were
related to the basic componeI}.ts of the.moose model (Table 2).
Based upon this assessment,the proposed project will affect the
population dynamics of upper Susitna moose and their predators.
The exact magnitude of these effects,however,will require
refinement as studies proceed and actual operation is commenced.
We estimated that based upon numbers of radio-collared moose
utilizing the impoundment areas in relation to the 1980 census,
from 1900 to 26qO moose could be directly impacted by construc-
tion and operation of the Watana and Devil Canyon impoundments.
These estimates comprised 8 to 11%of the total numbers of moose
occurring in GMU-13.rncluding·moose which could be secondarily
impacted by the proj ect through increased competition from di s-
placed moose,etc.,approximately 45%of the GMU-13 moose popula-
tion could be affected to varying degrees by the proposed pro-
jects.Moose modeling efforts currently underway will be adapted
to i;ncorporate anticipated effects of the project on the indi-
vidual components of the moose population .
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Table 1.Susitna Hydroelectric Project actions and their potential effect on moose
numbers,distribution and habitat in the Susitna River Area.
Project Action
Construction and operation
of dams (staging zone,
camps,and structures)
Spoil sites
Borrow areas
Reservoir clearing
Permanent village facilities
Main and accessory roads and
railroads.
Airstrips
Transmission line construction,
access and operation
Fill and operation of
impoundments
Environmental Effect
Loss of winter range.
Avoidance of adjacent winter range.
Loss of spring-summer range.
Avoidance of spring-summer range.
Possible impedence to migration.
Temporary loss of winter-summer range.
Temporary avoidance of adjacent habitat.
Permanent and temporary loss of winter habitat.
Permanent and temporary loss of spring-summer habitat.
Temporary avoidance of habitat.
Loss of habitat.
Temporary avoidance of adjacent areas.
Loss of habitat.
Avoidance of adjacent areas.
Loss of habitat.
Permanent and temporary avoidance (disturbance)
of adjacent habitat.
Mortality from collisions.
Increased human-related mortality (hunting,
defense of life,etc.).
Increased commercial and recreational development
on adjacent lands.
Loss of habitat.
Temporary avoidance (disturbance)of adjacent areas.
Increased human access and human-related mortality.
Temporary avoidance of habitat.
Increased access.
Temporary loss of habitat.
Eventual summer habitat improvement.
Potential for increased commercial and recreational
development
Permanent inundation of winter range.
Permanent inundation of spring-summer range.
Increased snow depths on adjacent area.
Increased snow drifting on adjacent areas.
Icing on vegetation due to open water.
Impedence of movements due to open water during
subfreezing temperatures.
Increased mortality from attempting to cross thin ice.
Impedence of movements and increased mortality due
to ice shelving.
Increased mortality crossing mud flats.
Unstable slopes causing habitat loss.
Crowding on adjacent habitat.
Increased human access.
Decreased vegetation productivity on adjacent lands
due to climatic changes.
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Table 2.Potential impacts of Susitna Hydroelectric development on annual moose population parameters.
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Moose Population
Parameters
Reproduction
Early spring and summer
mortality
(excluding predation)
Spring wolf predation
Summer wolf predation
Brown bear predation
Black bear predation
Projected Impact of Project Events
Decline in reproduction due to lower population size resulting
from increases in winter mortality,accidental mortality,
hunting and predator mortality from abnormal concentration of
moose and predator.
Decreased productivity resulting from decreased vigor because of
increased snow depths,decreased quality and quantity of forage
from weather,icing,and overbrowsing;increased disturbance
(both human and predator),and delayed spring green up.
Increase in still births due to reduced vigor of cows.
Increases in drowning and accidental deaths.
Increase in incidence of disease and pneumonia from delayed
greenup,poor nutrition,and more severe weather conditions.
Temporary increases in numbers of wolves may be influenced by
increased availability of prey leading to increased fecundity,
double denning and greater pup survival.Results in increased
predation on both calf and adult moose because of abnormal
concentrations of moose and their reduced health following
winter.
Short term severe overbrowsing of moose habitat and increased
mortality result in lower moose moose densities.
Lack of rapid wolf population response to lower moose numbers
intensifies effects of predation and lowers moose population
further.Eventually results in lower numbers of predators and
prey which "stabilize"at low level.
Similar to above.
Temporary increases in density of bears due to decreased
availability of south facing slopes and forced concentrations.
Result:Increased predation on calf and adult moose due to
abnormal conditions of moose and reduced vigor of adults and
calves from poor nutrition and increased winter severity.
Bear productivity and survival increase responding to increased
availability of prey.Results in increases in bear predation on
moose and drives moose population lower.Bears'ability to
utilize alternate food source maintains abnormal densities of
bears for long period and decreases moose population further.
Ultimately both bear population and moose population stabilize
at lower level.
Short term:
Bears lose den sites and for short period prey
intensively on moose before population declines.
Long term:
Due to decline in black bear population this source of mortality
declines.
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Table 2.(cont'd)
Moose Population
Parameters
Hunter harvest
Winter mortality
Winter wolf predation
Projected Impact of Project Events
Potential increase in harvest due to improved access and
increased vulnerability caused by moose occupying new habitat
areas not previously occupied.Depresses bull:cow ratios,
possibly leading to decreased productivity.
Probable that harvests will be limited by regulations;however,
dispersal of moose from impoundment areas could temporarily
increase and cause temporary increase in numbers of available
moose elsewhere in GMU 13.Ultimately,however,declines in
population size will reduce dispersals and reduce numbers of
moose available for harvest.
Winter mortality from starvation increases due to overbrowsed
range in areas adjacent to impoundments,loss of habitat,icing
on vegetation,increased snow depths and delayed spring
green-up.
Accidents increase from open water,ice shelving,and unstable
reservoir ice.
Concentrated wolf and moose populations on winter range result in
increases in surplus killing by wolves.Moose more vulnerable
due to increased snow depths,lower availability of forage,
poorer quality and quantity of remaining forage.
In addition,traditional escape routes no longer available due to
ice shelving and unstable ice conditions.Increased avail-
ability of prey result in wolf population increase.Time lag in
response of wolf population to decreased moose density further
depresses moose population.Eventually wolf population declines
and adjusts to lower moose density.Both populations "stahi-
lize"at lower levels.
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MITIGATION
Current investigation is focused on the experimental burn to
improve moose habi tat in the Alphabet Hills.
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CARIBOU
Plans to construct a large hydroelectric project on the Susitna
River wi thin the western portion of·the Nelchina caribou range
have raised concerns about the welfare of this important caribou
herd.Impact studies,which began in early 1980,continue with
the basic objectives of monitoring herd status,determining range
use and migratory routes and delineating subherds.Tpe results
of these studies are being used to evaluate potential impacts of
project construction,to make recommendations to minimize adverse
impacts and to evaluate mitigation measures.Extensi ve use of
historical records of the Nelchina herd has been made in the
analyses because of the changeable nature of caribou movement
patterns.Primary methodology for the study was the repeti ti ve
relocation of radio-collared caribou (Fig.2).Population esti-
mates were made with a modified version of the aerial photo-
direct count-extrapolation census procedure and by direct count.
During the winters of 1980-81 and 1981-82 the main Nelchina herd
wintered primarily on the northeastern Lake Louise Flat eastward
through the middle portion of the Gakona and Chi stoc·hina River
drainages to Slana.
During spring migration females moved across the Lake Louise Flat
onto the calving grounds in the foothills of the eastern Tal-
keetna Mountains on a broad front from Lone Butte to Kosina
Creek.Significant numbers of female caribou (probably over 50%
in 1982)passed through the upper Watana impoundment area enroute
to the calving grounds.Most males remained on winter range
during thi s period..
Calving occurred primarily in drainages of Kosina Creek although
some occurred along Goose Creek and the lower reaches of the
Black and Oshetna Rivers.Nelchina bulls were found scattered·
throughout the Nelchina range during this time mostly in transit
to summer range.
Summer
slopes
"bull
range.
range for Nelchina females was the northern and eastern
of the Talkeetna Mountains.Bulls were found scattered in
pastures"throughout the high country of the Nelchina
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During autumn considerable dispersal occurred from the Talkeetna
Mountains across the Lake Louise Flat.In 1982,perhaps 10%of
the female segment crossed the Susitna River and moved onto the
Jay Creek-Coal Creek plateau.
During the rut the herd appeared well mixed and moved eastward
from the Talkeetna Mountains across the Lake Loui se Flat.In
mid-October 1982 about 10%of the herd crossed the Susitna River
in the area of Watana Creek,migrated across the Jay Creek-Coal
Creek plateau and moved eastward to winter range.
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j,->1-1 \J ~(!)(!)n (!)6'~-:-~('J.g"';;;r 00 Cls....~'.JIi!IK<""....""'J:~w (!)
(!)(!)'llf
~-(!)~'If'
(!)~,.(!)IJ (!)
(!)~et!J e>
(!)rc~~*;CICI u ~e>(!)~~~~~r:(!);«.
C)4,I ~~(!)(!)~(!)('!)(!)6 ~-(!);«_._~l!'J __(!)__&_
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Figure 2.Distribution of main herd Nelchlna radio-collared caribou dur'lng entire study period,14 April.-f980 -16 October,1982:--
(!)=females;•""males.-
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Historically,Nelchina caribou have used the same calving grounds
however considerable variation in summer and winter ranges has
been noted.Migratory routes,although somewhat traditional,
have varied depending on the geographic relationship of the
calving grounds to summer and winter ranges.
The Nelchina herd was estimated to contain 18,713 caribou in
October 1980,20,730 in 1981 and 21,162 in 1982.Herd compo-
si tion in October 1982 was estimated at 47.7%females ~1 year,
26.5%males ~l year and 25.8%calves.
Calf survival from birth to 10.5 months of age was estimated at
0.58.Average annual survival for caribou ~1 year was estimated
0.88 for females and 0.92 for males (0.89 sexes combined).Re-
ported hunter kill of Nelchina caribou for the 1981-82 regulatory
year was 863 animals.
Observations of radio-collared (and non-collared)caribou indi-
cated the existence of a discrete subherd resident in the upper
drainages of the Susitna,Nenana and Chulitna Rivers (upper
Susitna-Nenana subherd (Fig.3).Although overlap with animals
from the main Nelchina herd occured during winter,summer and
fall they were separated during calving.An initial census
(direct count)of this subherd was attempted in October 1982 and
2,077 caribou were counted.Complications in evaiuating the
count resulting from delays from weather and movement·of mainherd
animals through the area make it desireable to repeat the census.
Potential Impacts of Proj ect Construction
Significant numbers of Nelchina caribou migrated through the pro-
posed Watana impoundment during three periods in 1982.During
spring migration (approximately 7 May -20 May)perhaps 50%of
the female segment moved-through the upper reaches of the Watana
impoundment area enroute to the calvinggrounds.In mid-August·
.about 15%of the female segment crossed the upper Watana impound-
ment area and moved onto the Jay Creek -Coal Creek plateau.
During the second week of October about 10%of the herd crossed
the Susitna River in the area between Fog Lakes and Kosina Creek
and migrated across the Jay Creek -Coal Creek plateau.It was
apparent,that even though the massive north-south migrations
across the Susitna which occurred with regularity in the past did
not occur,that large numbers of Nelchina caribou do currently
cross or move along the Susitna River in the area of the proposed
Watana impoundment.lflhile it is not possible to predict the
impacts of the Watana impoundment on migrating caribou it does
appear that the greatest potential for deleterious impacts occurs
during the spring migration to the calving grounds.This would
be during a period of transition from an ice-covered reservoir at
maximum drawdown with ice shelving and ice covered shores to an
open reservoir rapidly filling from spring runoff.Particularly
hazardous conditions could occur if windrows of broken ice accu-
mulated along the southern shore leaving the northern shore ice
14
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free.Caribou enroute to the calving grounds would at first
encounter open water but might have difficulty leaving the reser-
voir with the mass of jumbled,broken ice.Pregnant females are
often in the poorest condition of the year at this time and might
be particularly vulnerable to migratory barriers .
The presence of the impoundment would reduce optional migratory
routes available to the caribou which may be of particular impor-
tance during years with high snow accumulation in the Talkeetna
Mountains.
Crossings during summer and fall when the reservoir would be ice
free appear to pose less hazard.Caribou are excellent swimmers
and are known to cross much larger bodies of water than the pro-
posed impoundment.·Young calves might have problems if the
migrations occurred shortly after calving.Rafts of floating
debris could cause problems for the first few years after filling
the impoundment.Mortalities of moose who could not reach shore
because of floating debris have been reported in impoundments in
Canada (Ballard,pers.comm).
It seems inevitable that Nelchina caribou will again use the area
north and west of the Susitna as summer and winter range as they
have done in the past.When that occurs the entire female seg-
ment of the herd will cross·or migrate around the impoundment
area twice or more each year.
The proposed access road from the Denali Highway to the Watana
damsite which parallels the eastern border of the Chulitna
Mountains will probably immediately impact the upper Susi tna-
Nenana subherd and will impact the main Nelchina herd when it
again uses the area north and west of the upper Susitna in large
numbers.Probable impacts include increased mortality from
vehicle collisions,impeded east-west movements,increased hunter
access and possibly increased predation.Movements of radio-·
collared caribou along with general observations indicated that
perhaps 35-50%of this subherd migrated westward into the Chu-
Ii tna Mountains each summer returning to the east in the fall.
Thus perhaps up to half of this subherd could be exposed to the
problems associated with a road crossing in a treeless area twice
a year.The Chulitna Mountains are excellent summer range and
should the main herd again spend summers in the area they would
also encounter the-access road.
Reports on reactions of caribou to roads and vehicular traffic
are somewhat contradictory.Cameron et ale (1979),in the most
thorough study to date,documented avoidance of the Tran$-A1askan
Pipeline corridor by females and calves during summer (the Denali
access route passes through summer range which historically has
been important for the female-calf segment of "the main Nelchina
herd).They also suggested avoidance by large groups,group
fragmentation and/or decreased group coalescence near the pipe-
line corridor.Horej si (1981)reported that caribou exhibited
16
-
""""
.....
"...
-
signs of anxiety and fear when encountering a fast-moving vehicle
and speculated that they might avoid well-traveled highways.
Klein (1971)reported that well-traveled highways have obstructed
the movement of wild reindeer in Norway.It has also been sug-
gested the roads might increases susceptibility of caribou to
predators (Robey 1978).
In another study it was concluded that mountain caribou became
habituated to the presence of a highway and traffic and continued
to use a traditional movement route despite harassment and mor-
tality (Johnson and Todd 1977).Nelchina caribou continue to
cross the Richardson Highway,often in large numbers,and have
done so during many years since about 1960 (Hemming 1971).
Calving by members of the upper Susitna-Nenana subherd is dis-
persed over three large regions:Chuli tna Mountains·;Deadman
Creek,Brushkana Creek and Butte Lake drainages;and the head-
waters of the Susitna River.Because of this it appears impos-
sible to route the access road so that calving females will be
completely avoided.However because of the dispersed calving
only a small proportion of calving females would be impacted
wherever the road is placed.-
From 1979 through 1981 about 20%of the annual harvest (x of
120/year)for the NelchLna herd came from the range of the upper
Susi tna-Nenana subherd.This harvest while comprised mostly of
subherd animals undoubtedly contained some bulls from the main
herd (which summered in the area)and possibly a few females
which had dispersed from the Talkeetna Mountains.This level of
harvest is wi thin the limits of a herd this size.Concern has
been expressed that increased hunter access via the Watana access
road could result in overharvest.Alaska Department of Fish and
Game regulatory procedures should be adequate to prevent this
from happening.
Habitat loss from fJooding and from borrow areas does not appear
to be a serious problem.Both developments are proposed for
small areas of low quality caribou habitat.Human acti vi ty as-
sociated with construction and operation could possibly cause
avoidance of very local areas.Increased aircraft traffic should
not be a serious problem provided sui table elevation is main-
tained and traffic is restricted in the calving grounds of the
main Nelchina herd.
Perhaps in the long run the maj or impact of the Susi tna hydro-
electric development on the Nelchina caribou herd will be a
contribution towards gradual,long term cumulative habitat
degradation rather than immediate catastrophic results.The
proposed hydroelectric project is only one (although the major
one)of a number of developments which will probably occur in the
Nelchina range.Considerable mining activity already is taking
place in the southeastern Talkeetna Mountains,traditional summer
range.A state oil and gas lease sale.is planneo.for the Lake
17
"""
-
Louise Flat,a major wintering area.The Bureau of Land Manage-
ment is planning to open much of the Nelchina Basin to oil ex-
ploration.Considerable land is passing from public to private
ownership through the Alaska Native Clai,ms Settlement Act and
through state land disposal programs.While no single action may
have a catastrophic impact it seems likely that long-term cumu-
lative impacts will result in a lessened ability for the Nelchina
range to support large numbers of caribou.Habitat destruction,
increased access,disturbance,and partial barriers to movement
will all probably contribute to thi s.
18
WOLF
In 1982,wolf studies continued in the Susi tna River Basin to
investigate potential impacts of the proposed Susi tna Hydro-
electric Project.Between 1 November 1981 and 31 December 1982,
46 wolves were captured and outfitted with transmitter-equipped
collars to enable researchers to document movements,denning and
rendezvous locations,habitat use,and food habits.Throughout
the period,a total of 12 packs and 1 lone wolf were known to be
using areas in or adjacent to the Devil Canyon or Watana impound-
ment zones.Because 4 of these packs were not located unti 1
December 1982,they were not included in most analyses.Four
hundred radio locations yielded 501 wolf sightings upon which
this report is based.
A population estimate of 64 wolves at the end of 1982 in the
upper Susitna River Basin was made based on knowledge of 9 packs
with an average of 4.9 wolves per pack,added to an estimate of
wolves in an addi tional 4 suspected packs (Fig.4).
Annual fluctuations in wolf numbers were estimated based on
several criteria.Recruitment to packs is due to pup production
and immigration into the area.Illegal aerial hunting accounted
for the highest mortality (24%)wi thin 8 intensively monitored
packs.Sixteen dispersals accounted for an additional 18%loss
of wolves from the basin.
Terri tory sizes of 5 intensively monitored packs ranged from
127 mi 2 to 602 mi 2 (329 km 2 to 1559 k 2 ),and averaged 344 mi 2
(891 km 2 )in 1982.Territory sizes vary considerably among
packs,probably due to pack size,prey densities,frequency of
moni toring,and adj acent pack boundaries.
Distribution of wolf packs is suspected to be virtually complete-
in the basin,with elevational use generally restricted to less
than 4,000 ft.Elevational distribution varies seasonally and is
probably dependent on relative densities of maj or prey.Moose
and wolves both displayed use of lowest annual elevations in
February,with a general increase in elevational use until
October wi th subsequent declines thereafter.
Analyses of food habits of wolves in 1982 were based solely on
aerial observations of wolves at kills.Moose of all age classes
represented 55%of the diet,with caribou compri sing 36%.No
analysis of 1982 scat collections has been done,but it was sus-
pected that aerial quantification of food habits underestimates
percentage of small mammals (non-ungulates)in the diet.
Impacts
Impacts of the proposed impoundments and their associated borrow
pits,transmission corridors,work camps and facilities are dif-
ficul t to quanti fy at thi s time.However,based on earlier
research and that reported herein,some impacts can be estimated.
19
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FIgure'4.Known and 8u8pected pack boundartee for thirteen wolf packl In the upper SUIltna River Balin from December
1981 through December 1982.
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Probably the most significant impact the impoundments will have
on wolves will result from a change in population density,dis-
tribution,sex and age composition and/or physical condi"tion of
moose and caribou.The majority of the wolf's diet in this area
is moose,and any decrease in prey numbers will probably be
reflected in both wolf density and distribution.Ballard et al.
(1983)estimated that approximately 1,900-2,600 moose wi 11 be
directly impacted by the impoundments.During the impoundment
filling stage and for at least a year following inundation,there
wi 11 probably be an increase in wolf numbers in response to
higher concentrations of moose adjacent to the impoundments.
There will be a high number of displaced moose which will be con-
centrated adjacent to the reservoirs due to the decreased avail-
ability of usable habitat.However,the duration of this rela-
tively high moose concentration will probably be short,i.e.2-3
years.After that,deterioration of the habitat will undoubtedly
result in relatively lower moose numbers.Ultimately wolf
numbers will be reduced but for,a good period of time they will
remain relatively high and further depress the moose population
and prevent it from recovering.
Access roads and the proposed permanent village for project per-
sonnel will result in a significant increase in human use of the
area.Correspondingly,there may be a higher incidence of man-
caused mortality upon wolves.Trappers and hunters can .be
expected to "harvest more wolves than current "levels,but that
harvest will probably be of minor importance to overall wolf pop-
ulation numbers.Indirect effects upon wolves"resulting from
higher human populations will probably also occur.Activity near
den and rendezvous sites in early summer will certainly disrupt,
and in some cases,will probably cause wolves to abandon den and
feeding sites.Den"site abandonment could lead to higher pup
mortality.
Inundation of den and rendezvous sites,travel corridors and·
hunting/feeding areas will eliminate portions of wolf terri-
tories.Loss of this habitat will force wolves to readjust
territory boundaries and will probably result in increased inter-
pack strife.Since present wolf mortality from some of the packs
adjacent to the Susitna River are low (Watana Pack in particular)
with subsequent high dispersals to surrounding areas,this area
acts as a reservoir in supplying wolves to adjacent areas.
Should mortality within these packs increase,there will probably
be less di spersal away from the area.Consequently,the reduc-
tion of wolf numbers adjacent to the impoundments may well affect
not only those packs immediately adjacent to the river,but also
packs far removed from the area.Movements of over 50 miles
(80 km)away from the Watana terri tory by wolves which either
joined new packs or initiated new packs have been recorded.
-To better describe the effects of habitat inundation on "wolves,
the Watana Pack (because of the relatively high number of reloca-
tions)was selected for a further analysis.As mentioned
21
-
--
!
!
earlier,the Watana Pack occupied a t~rritory of 482 mi 2 (1246
km 2 )within and adjacent to both the proposed Watana and Devil
Canyon impoundments in 1982.Indeed,26 out of 58 (45%)of the
relocations of Watana Pack members were at or below high pool
level of the impoundments.During the first half of the year
(January through June)over half (57%)the recorded observations
were at or below maximum pool level.Further,it was calculated
that of the 482 mi 2 (1248 km 2 )Watana Pack terri tory,51 mi:1
(132 km:1)was in elevations over 4,000 ft.and thus used very
little «4%)by pack members.Reducing the 482 mi:1 (1248 km 2 )
territory by 51 mi 2 (132 km 2 )leaves 431 mi:1 (1116 km 2 )of usable
habi tat.When the area inundated at high pool level (2200 ft.
elevation for Watana,1450 ft.elevation for Devil Canyon)was
planimetered,an area of 55 mi 2 (142 km:1)would be lost to the
pack.This would account for 13 percent of the land area
utilized by the_pack.Forty-five percent of the relocations were
recorded on this 13%of the total territory,indicating that
those elevations with their associated habitat are preferred by
the Watana wolves.As mentioned in an earlier section of this
report,this is undoubtedly due,at least in part,to higher
concentrations of moose in this elevational stratum.
At the time this report was prepared,information on exact loca-
tions and extent of area covered by encampments,borrow sites and
road and transmission corridors was not available.However,pre-
liminary site locations have been mapped,and their location will
further limit'the extent of the Watana terri tory.The exact
percent of habitat loss of the Watana territory is not known.In
particular,quarry sites A and B,and borrow sites D,E,F,I,J,
and L will at least have portions within the Watana territory and
will impact the Watana wolves during and/or after construction of
Watana Dam.
The percent of various elevational strata available to the pack
(calculated by random selection of 482 points within the Watana
terri tory)compared to the percent of radio-locations at those
various elevations shows that between 1801 and 2200 ft.were sig-
nificantly preferred elevations (p(0.005).These e1evational
strata were available to Watana wolves in 13 percent of their
terri tory,yet were used on 45 percent of the locations.The
inundation of this zone will undoubtedly affect the shape and
extent of the Watana terri tory and subsequent recruitment and
mortality.
22
BLACK BEARS AND BROy-IN BEARS
In 1982,three components of Su Hydro studies were initiated.
These included a black bear census in the upstream area,an anal-
ysis of fecal samples,and the initiation of a bear study down-
stream of the proposed Devils Canyon dam site.This downstream
study is designed to reveal impacts of project-related changes in
bear food abundance (primarily salmon)on resident downstream
bear populations (Fig.5).Black bears are emphasized in thi s
downstream study.
Preliminary results of the new components of the Su Hydro bear
project are discussed in detail in this report.Components of
continuing studies were analyzed in detail only when new findings
in 1982 altered or significantly strengthened preliminary find-
ings reported in our earlier report (Miller and McAllister 1982).
Bear population models intended to assi st in predictions of
impacts and evaluations of mitigation alternatives are under
development and will form a subsequent addendum to this report.
Additional information on brown bear population parameters essen-
tial to track project impacts on bear populations through changes
in productivity was collected in 1982.Initial post-emergence
litter size of new-born cubs in 13 litters (1978-1982)was 2.15
(range 1-3).Nine of 2~cubs in 10 litters (43%)have been lost
between emergence from dens as cubs and emergence as yearlings.
Available data suggest a high rate of loss from yearling litters
in 1982,the year following an apparent widespread failure of the
berry crop.A high proportion of adult females (54%)may produce
cub litters in 1983,2 years after the apparent berry crop fail-
ure.Such pulses in cub production would produce an uneven age
distribution in the brown bear population and an analysis of the
harvest data suggests the presence of this pattern.
Adult females have smaller home ranges in years they have litters
of newborn cubs than in other years.Excluding such females from
the analysis,home ranges of brown bears were smaller in 1982
than in the preceding year when berry crops were poor.These
observations suggest that project-related changes in the distri-
bution,abundance,or availability of food resources will affect
bear populations in the study area.This influence would likely
be expressed by decreased survivorship of yearling and subadult
brown bears and an increase in reproductive interval.
The previously reported movements of project-area brown bears to
Prairie Creek to fish for salmon was repeated in 1982.Prairie
Creek is considered an area of critical habitat importance to
brown bear populations in the study area.
None of the brown bear dens located in this study would be inun-
dated by the proposed impoundments although as suggested in last
year's report,some displacement from denning areas would result
form access roads and borrow areas.
23
N
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Figure 6.Downstream black bear study are.(Intenllve),polygon enclos.s the 627 sq.km used by 10 radio-collared black bear.,
~17 polnta•.(1 em =2.3 km).
"""'I
I
I
Continuing studies on black bear populations in the impoundment
area were conducted in 1982.A preliminary summer population
estimate of 86 black bears (95%CI=47-172)was made using Lincoln
Index techniques.Numerous sources of potenti al biases were
identified in this estimate,most of these would tend to yield an
underestimate.This procedure will be repeated in spring 1983
when a different array of sightability biases would exist.The
possibility that emigrations of subadult black bears during the
poor berry year of 1981 resulted in the lower-than-expected popu-
lation estimate is discussed.
Limited sampling of bear abundance in two habitats in two loca-
tions provided support for the hypothesis that black bear move~
ments in the upstream study area during late summer are motivated
by the relative abundance of berries,especially blueberries.At
this time bears tend to move upstream and away from the impound-
ment area.More extensive berry sampling by the Plant Ecology
sub-task is recommended for 1983.
Data collected in 1982 support our hypothesis of an inverse rela-
tionship between black bear productivity and food abundanc~.The
poor berry crop in 1981 created a situation where 19 of 20 radio-
collared black bear females may produce cubs in 1983.This
factor is significant because a large proportion of black bear
habitat (especially spring habitat)is expected to be inundated
by the Watana impoundment.This habitat loss will likely result
in decreased productivi ty in the post-impoundment period.
Analyses of a small sample of black bear scats in the upstream
study area suggests the importance of Equisetum in spring diets
along with grasses and sedges.These data tend to support our
hypothesis that early spring food in the area to be inundated by
the ·Watana impoundment may be important to upstream bear popula-
tions.The relative availability of these items inside and out-
side of the impoundment area must be established by Plant Ecology
subtask studies.
Of 24 black bear dens found in the vicinity of the proposed
Watana impoundment,13 will be flooded by the impoundment.In
contrast,minimal impacts on black bear dens through inundation
are anticipated in the vicinity of the Devils Canyon impoundment.
Continued high reuse of the same den sites suggest low avai l-
ability of acceptable den sites and a.corresponding major impact
through destruction of den sites in the vicinity of the Watana
impoundment.
Work was initiated in 1982 to evaluate impacts of reduced salmon
spawning in sloughs downstream of .Devils Canyon on downstream
black bear populations.Salmon spawning sloughs identified by
~Fisheries subtask workers were inspected in 1982 and ranked rela-
tive to bear use and salmon abundance.The movements of all 10
downstream radio-collared black bears (with 1 possible exception)
indicated use by the bears of spawning salmon during 1982.
25
I
,~
!
Radio-tracking data indicate 5 bears used identified slough
areas,2 fished in the mainstem Susitna or its tributaries,and 2
others fished in the Chulitna or its tributaries.Another bear
may also have fished in the mainstem Susitna but the evidence is
inconclusive.Bear feces collected in the vicinity of the salmon
sloughs contained more devils club (Oplopanax horridus)than any
other item.However,there was much direct evidence of bear use
of salmon caught in the sloughs.Possible reasons for this bias
are di scussed.Addi tional work is required to determine the
impacts of reduced salmon spawning in slough habitats on
downstream black bear populations.
26
""1
i
!
WOLVERINE
This report summarizes data collected during Phase I,but is
updated to include data and analysis through November 1982 of the
Phase II studies.Since inception of the project in April 1980,
17 wolverine have been captured a total of 19 times.All were
captured by darting from a helicopter and were fitted with trans-
mitter-equipped collars to allow investigators to gather certain
ecological data.A total of 303 point locations have been made
on wolverine in the middle Susi tna River Basin.One hundred
ninety-four locations were gathered by radio telemetry,and the
rest were from harvest records,track sightings and uncollared
wolverine observations.
Minimum home ranges for 12 wolverine in the middle Susitna basin
are shown in Fig.6.Calculations have shown that estimates of
wolverine home ranges increase in size depending upon the length
of time of radio contact.Thus,calculations that have relied on
data gathered for less than 1 year probably underestimate annual
home range size.Only one wolverine has been monitored for an
entire year (adult male no.116040)and he occupied a home ranqe
of 627 km 2 (242 mi 2)•Using this figure,it was estimated that
78 wolverine inhabit the 16,319 km 2 (6301 mi 2 )Susitna River
Basin,averaging one wolverine per 209-km 2 (81 mi 2)•
Elevational movemerits by instrumented wolverine showed signifi-
cant differences between summer and winter ranges,averaging
969 m (3,178 ft)and 842 m (2,761 ft)elevation,respectively.
It was suspected that this was due to differences in prey dis-
tribution and availabili ty on a seasonal basi s.
Potential Impacts
The inherent elusiveness and low densities of wolverine through-
out their present range have made it largely impractical to
conduct ecological studies (van Zyll de Jong 1975).However,
throughout most of Alaska,wolverine numbers are probably com-
parable to what they were a century ago simply because of minimal
human acti vi ty in the state.Additionally,technological ad-
vances in radio telemetry equipment and techniques have enabled
researchers to gather previously unobtainable data on movements
and other ecological parameters necessary for making sound man-
agement decisions regarding predators.
Van Zyll de Jong (1975)and Hornocker and Hash (1981)have sug-
gested that one factor leading to decreased wolverine numbers is
probably human disturbance.The recent focus on resource devel-
opment in Alaska may cause parallel reductions.
Telemetry data suggest that the Susitna River presents no impe-
diment to wolverine,and many crossings were documented.The use
of elevations below the high pool level (2200 feet)was mainly
27
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Figure 8.Minimum home ranges of twelve Inltrumented wolverine In the middle SUlltna ,River Balin.1980-1982.
-~
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during the period November through January,when scavenging on
big game is an important portion of the diet,and that food
source is distributed largely in the impoundment zone.
Although actual loss of habitat through inundation and facilities
development will reduce habitable land areas,this factor alone
is not likely to significantly alter the wolverine population.
However,of much greater concern is the effect this will have on
winter food supplies,"thus secondarily impacting wolverine dis-
tribution,producti vi ty and abundance.
Ballard et al.(1982)estimated that ~pproximately 2,400 moose
will be severely impacted by the proposed project.Three scen-
arios are possible to describe what that moose population will
ul timately do.(1)Moose wi 11 be concentrated in the remaining
habitat along the reservoir borders.This will probably lead to
deterioration of the existing habitat,by overuse of the range,
and ultimately,a reduction,through winter kill,of the moose
population.Should this scenario happen,there would probably be
an increase in wolverine numbers for a period of 3-5 years,
followed by a.substantial reduction in the population because of
a lack of winter carrion.(2)Moose will migrate out of the
Basin in search of better range~This would probably result in
lower wolverine densities,as winter carrion would not be as
available."(3)Massive dieoffs of moose would occur during
inundation and immediately after maximum pool level is attained,
mainly from accidental deaths (i.e.shifting and thin ice,
drownings,concentration of individuals with increased predation
resulting).Should this occur,wolverine numbers will probably
increase for 1-3 years following inundation,with subsequent
reduction in numbers when carrion is no longer available in such
quantities.
29
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--
"""'
DALL SHEEP
During Phase 1 studies,a mineral lick used by Dall sheep was
discovered in a location adjacent to the proposed Watana impound-
ment.The lick use area occurs on a steep bluff on the west bank
of Jay Creek,from creek bottom (200Q ft/610 m in elevation)to
the rim (2450 ft/747 m).The Watana impoundment normal maximum
operating level is designated as 2185 ft/666 m wi th an average
annual drawdown of 120 ft/36.6 m,which will cause inundation and
erosion of some of the lick use area.Also,the lick's close
proximity to the impoundment will make the sheep seasonally vul-
nerable to disturbance from construction,transportation and
recreational activities.During 1982,aerial and ground obser-
vations were made of this site (Table 3)and other licks to
observe sheep use.However,due to a lack of personnel,obser-
vations were infrequent and not sufficient to adequately deter-
mine the extent of lick use.Aerial sex and age composi tion
surveys of the Watana Hills sheep population were conducted on 23
March and 3 August 1982.During the August survey,another
possible lick was located approximately 4 mi/6.5 km northwest of
the Jay Creek lick.Four legal rams were reported taken from the
rlatana Hills population during the 1982 hunting season.
Proj ect Impacts
Impacts of Watana Impoundment
The Watana Hills sheep population appears to be vulnerable to
severe impact from the proposed Watana impoundment because of
disturbance to the Jay Creek lick area.This lick,adjacent to
the proposed Watana impoundment,is used by sheep in early sum-
mer.A group of 15 sheep (7.5%of the surveyed summer popu-
lation)was the largest seen using the lick during 1982.Up to
23 sheep (13%of the observed 1980 population)have been seen at-
the lick at one time (Tobey 1981),indicating that a significant
portion of the population uses this lick.It is likely that
sheep travel some distance to use this lick as both winter and
summer surveys have located most of the population 7 or more air
mi/11.3 km from the Jay Creek lick.The Jay Creek lick area and
much of the terrain traveled from observed summer and winter
range is atypical sheep habitat,being relatively flat with
shrubland and trees and little rocky cliff escape habitat.This
indicates the importance of the Jay Creek lick,especially when
the East Fork lick is so much closer to the majority of sheep
sightings and in more typical sheep habi tat.
The cycle of filling and draining in the Watana impoundment will
subject the lick area to flooding and erosion and possibly will
leave ice shelves on portions of the lick area during the peak
lick use season.Together,the mineralized lick substrate,rock
30
Table 3.Observations at the Jay Creek lick during 1982.
Total
Date Time Sheep Rams Unclassified Obseliver
23 March 0 J.Westlund
(aerial obs.)
27 May 1600-2000 0 J.Westlund
(ground obs.)
~
28 May 0600-1000 0 J.Westlund
(ground obs.)
~29 May 0900-1100 0 J.Westlund
1600-2000 (ground obs.)
30 May 0700-1300 0 J.Westlund
(ground obs.)
8 June 1530 12 12 J.Whitman
{aerial obs.}
10 June 1400 15 15 (3 at lick,12 0.6 km south)J.Whitman
(aerial obs.)
17 June 1030 15 9 6 R.Fleming
(aerial obs.)
24 June 1539 1 1 St.Miller
{aerial obs}
29 June 1400 0 St.Miller
(aerial obs.)
8 July 1533 2 2 St.Miller
,,~(aerial obs.)
3 August 0 J.Westlund
(aerial obs.)
I~14 October 1200,1700 0 (no tracks seen either)J.Whitman
(aerial obs.)
,~
-
-
I~
31
-
.-
~,
outcrops providing escape cover,other resting areas,and trails
are used by the sheep.Flooding,erosion and ice shelves on
portions of these components may lessen or destroy the value of
the lick to the Watana Hills'sheep.In addition,sheep attrac-
ted to the lick area may be seasonally vulnerable to disturbance
and habitat degradation from timber harvest in the impoundment
and other human activities.
The Watana Hills is a small isolated sheep population,used by
local guides and sheep hunters (see also Ballard et al.1982).
The nearest additional sheep habitat occurs southwest across the
Susitna River around Mt.Watana,and also farther northeast in
the Clearwater Mountains across a larger valley.Aerial surveys,
other sightings and the distances involved suggest that the
Watana Hills sheep may have more interchange with the Talkeetna
Mountains population to the southwest.This interchange may pro-
vide the opportunity to maintain a viable sheep population in
the Watana Hills,by emigration from the larger Talkeetna Moun-
tains population.The Watana impoundment,with seasonal hazards
of a large width of open water,ice shelving and unstable ice
conditions and mud shelving may depress or eliminate sheep immi-
gration from the southwest.Thi s would make any detrimental
impacts of the project on the Watana Hills sheep population even
more serious,as population recovery from a project impact could
be greatly slowed or made impossible by loss of immigration
opportunities.
Climatic Impacts
A delay in spring plant growth in areas near the Watana impound-
ment (Exhibit.E,FERC License application)may degrade some of
the Watana Hills and Mt.Watana sheep habitat.If the Watana
impoundment causes additional snow accumulation in nearby areas,
important south-facing"slopes in the Watana Hills may become
poorer winter habi tat.
I ncreased Human Access
The project development will undoubtedly increase fixed-wing and
helicopter traffic.Low-flying aircraft,especially helicopters,
are known to disturb Dall sheep (Linderman 1972,Nichols 1972,
Lenarz 1974).Groups of ewes and lambs (possibly including young
rams)react most strongly to helicopters (Lenarz 1974).The
dangers of aircraft disturbance include injuries sustained by
sheep while fleeing (Linderman 1972),wasted metabolic energy
expense (which could become critical if the disturbance is
repeated during stressful winter or lambing periods)(Geist
1971b),and abandonment of habitat (Linderman 1972),which could
lower the population size.However,some sheep show habituation
to aircraft that maintain regular flight patterns and do not
approach sheep closely (Lenarz 1974,Summerfield 1974,Reynolds
1974).MacArthur et al.(1982)found no cardiac or behavioral
responses by unhunted adult bighorn sheep to helicopters and
fixed-wing aircraft flying 400 m or more away.
32
,~
-
,~
--
Roads and reservoirs developed by the project will allow
increased access by vehicles and hikers who can also disturb
sheep (Tracy 1976 1 MacArthur 1982).One-~area where the Denali
National Park road was built directly through sheep habitat
receives less use by sheep now than in the early 1940's,but the
exact cause of this apparent abandonment is not clear (Tracy
1976).Tracy (1976)also reported that a few Dall sheep (mostly
ewe and lamb groups)in Denali National Park were disturbed while
crossing a small valley with a road when vehicles were present.
Tour buses stopping,people exiting and making loud noises
increased (respectively)the disturbance to the sheep (observed
by their behavior).Reactions of sheep to moving vehicles more
than 200 m away were minimal (Tracy 1976).These sheep were
habituated to traffic and not hunted.Among unhunted sheep popu-
lations,sheep may habituate more readily to human presence
(Geist 1971b).
MacArthur et al.(1982)documented relatively few cardiac
responses (8.8%of trials)and fewer behavioral responses (0.9%
of trials)of bighorn sheep to vehicle passes.Most of these
responses (73.7%)occurred when the vehicle passed within 25 m.
Humans approaching on foot l especially accompanied by a dog,
elicited stronger responses (MacArthur et al.1982).These sheep
were living in an unhunted sanctuary and had been regularly
exposed to humans and vehicles along a nearby road.No ewes with
lambs were monitored,which are more sensitive to disturbance
(Murie 1944 1 Smith 1954,Jones et al.1963).
MacArthur et al.(1982)recommended restricting human activities
to roads and established trails,and discouraging dogs in areas
of sheep habi tat.
Population Distribution
The difference in sheep numbers between the winter and summer"
surveys in the Watana Hills may be due to the poorer observation
conditions during "the winter surveyor because fewer sheep
inhabi t the Watana Hills during winter.Future surveys and
scrutiny of sheep movements may help clarify this discrepancy.
The few observations of sheep in the Mt.Watana-Grebe Mountain
range do not indicate that these sheep will be directly affected
by the impoundments or other ground construction acti vi ties.
However l sheep have been observed in the past on Mt.Watana near
the proposed impoundment (Tobey 1981)and may continue to do so.
More surveys and observations of sheep in this area are needed to
delineate seasonally important range.
The few observations of the Portage-Tsusena Creeks sheep also
indicate that they do not occupy areas close to the impoundments,
Denali access route or the northern route of the transmi ssion
lines.However,more complete seasonal surveys are needed to
confirm this.
33
-
Mitigation Recommendations
Lowering Watana's maximum reservoir level to 2000 ft/609.6 _in
elevation would eliminate much of the physical disturbance to the
Jay Creek lick.Also,certain methods and scheduling of con-
struction activities and access would reduce the impacts of the
Susi tna Hydroelectric proj ect on sheep.
Timbe-r harvest wi thin 2 air mi/3.2 km -of the Jay Creek lick
should be restricted to the months of September through April.
The area wi thin aD.5 mi/O.8 km of the lick should remain
untouched by clearing activities,including roads,logging equip-
ment and debris,except for those portions below the minimum
operating level (2065 ft/629.4 m).Any _clearing wi thin 2 air
mi/3.2 km of the lick should be delayed as long as possible until
just before the reservoir begins filling.This will condense the
physical effects of the Watana development into a shorter time
period.
Access for proj ect personnel and recreational users should be
restricted to minimize di sturbance in areas of sheep habitat.
Limi ting off-road access to certain trails (away from lambing
areas and mineral licks)should be considered.Air -traffic
should be prohibited below 1000 ft/304.8 m above ground level in
areas of sheep habitat.Helicopter landings within 1.0 mi/1.6 km
of mineral licks should be prohibited during'l May -15 July or
later,depending on the results of seasonal lick use studies.
Boat and ground access within 1.0 mi/1.6 km of the Jay Creek lick
and other mineral licks should -be prohibited from 1 May -15
July,or later,if lick use continues through the summer.
If the project substantially reduces availability of mineralized
suhstrate at the Jay Creek lick,options of mining or blasting
the lick area to expose additional substrate,or supplying appro-
priate mineral elements near the Jay Creek lick or other areas-
could be considered.
34
BELUKHA WHALE
Belukha surveys were,flown in Upper Cook Inlet between May 17 and
Aug.27,1982.A concentration area was identified nearshore
from the mouth of the Little Susitna River to the mouth of the
Beluga River (Fig.7).Exact timing of use of the area has not
been determined,however,the concentration appeared to build up
in late May and lasted through mid-June.It is probable that
this concentration was in part associated with calving and
breeding although no calves were positively identified because of
generally poor viewing conditions.The concentration appeared to
involve 200 to 300 animals,however accurate counts were not pos-
sible because of,again,poor viewing conditions.The Belukha
concentration near the mouth of the Susi tna .Ri ver appeared to
coincide with the arrival of large numbers of eulachon which
spawned in the lower Sus~tna River in late May and early June.
This run of eulachon was estimated to total several million fish.
King salmon are probably not particularly important to this
concentration of belukhas although large male belukhas probably
do take some king salmon.Probably the only other salmon species
from the Susitna River system available in sufficient numbers to
be considered significant prey to the belukhas concentrated in
late May and early June would be the sockeye.No information is
presently available which would allow conclusions on belukha
predation on salmon smol ts from the Susi tna River.
Gi ven the present state of our knowledge,we cannot accurately
predict impacts on Cook Inlet belukhas from the proposed dams on
the Susi tna River.It is possible that the overall population
could suffer reduction in numbers both directly by alterations in
the habitat,particularly the concentration area near the mouth
of the Susi tna River and indirectly by reduction of available
food species.
Potential Impacts
Quantification of impacts of the Susitna hydroelectric project on
belukhas at the present time is not possible.This type of
project has the potential for reducing the numbers concentrating
near the mouth of the river by reducing the available food or by
al tering the heat budget of the river.However the overall
effect on the availability of anadromous fish to belukhas is
predicted to be small.There may be no alteration of the heat
budget of the river realized by the belukhas at the mouth of the
river although very little data are available to prove this.
Approximately 5 to 8%of the total adult salmon returning to the
Susi tna River system spawn in the area from Talkeetna to Devil
Canyon;the area which is predicted to be the most heavily
impacted by dam construction.The slough habitat in this area is
predicted to be completely lost,thereby eliminating approxi-
mately 5%of the chum salmon from the system as well as a small
35
1 1 )1 J ]»1 -11
.~j _J j j •.,
W
0"1
Figure 7.Upper Cook Inlet:Belukh«atudy area.
oNORTH It ,J tr 19 rnl
i~
number of sockeye.This means that a small amount of food in the
form of adult chum and sockeye will no longer be available to the
belukhas after dam construction.Since we have no quanti tative
measure of the importance of these species to the belukhas,~o
estimate of impact can be made except to guess that it will
probably be slight .
.Impacts on the eulachon runs which enter the Susi tna River are
assumed to be slight as they remain in the lower reaches of the
river (Bruce Barrett ADF&:G pers.comm.).This species may be
extremely important to the belukhas and it is possible that any
reduction ()f eulachon ·could severly impact·the belukhas.
Although most impacts from either heat budget alteration or food
reduction are likely to be slight,we cannot accurately predict
the overall effect on the belukhas.If any environmental perter-
bations effect the belukhas in upper Cook Inlet,it is likely
these effects will take the form of a reduction in the population
in Cook Inlet.Given our present state of knowledge,a reduction
in the belukha population of upper Cook Inlet would not be
detectable unless it were greater than a 50%to 75%reduction in
the entire population.Even a reduction of this magnitude could
go unnoticed for several years as no systematic monitoring of the
population is planned.
~,
37
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I~
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38
sheep to an FH-I100 heli-
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compressor station noise
Stud.Biolog.Rep.Sera
I~
Linderman,S.1972.A report on the sheep study at the Deitrich
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39