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Al.ASKA POWER ,AUltfORIll!
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BIG GAME STUDIES
Volume VI BLACK BEAR and BROWN BEAR
Sterling D.Miller
ALASKA DEPARTMENT OF FISH AND GAME
Submitted to the Alaska Power Authority
April 1983
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hO,~!S
SUSITNA HYDROELECTRIC PROJECT
PHASE I I,first annual progress report
Big Game Studies
Volume VI Black Bear and Brown Bear
Sterling D.Mi ller
Alaska Department of Fish and Game
Submi tted to Alaska Power Authori ty I April 1983
"ARLIS
Alaska Resources
Library &Informatlon ServIces
Anchorage,Alaska
Results reported herein deal with portions of a continuing study
and should be treated as tentative.Do not cite in technical
publications wi thout permission from author:
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"...
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 I,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 mi tigation 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 publicati'on 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 I I.
Volume IX.
Big Gam..=Summary Report
Moose -Downstream
Moose -Upstream
Caribou
Wolf
Black Bear and Brown Bear
Wolverine
Dall Sheep
Belukha Whale
ARLIS
Alaska Resources
Library &InfonnatlOll ServH'e·
Anchorage,Alaskb
I.SUMMARY
In 1982,three components of SU Hydro·studies were initiated.
These included a black bear census in the upstream area,an ana1-
ysis of fecal samples,and the initiation of a b~ar study down-
stream of the proposed bevi1s 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.Black bears are emphasized in this 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 McA1iister 1982).
Bear population·models intended to assist 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-
tia1 to track project impacts on bear populations through changes
between emergence from dens as cubs and emergence as yearlings.
litter size of new-born cubs in 13 litters (1978~1982)was 2.15
(range 1-3).Nine of 21 cubs in 10 litters (43%)have been lost
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inproductivi ty was collected in 1982.Initial post-emergence
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·....
Available data suggest a high rate of loss from yearling litters
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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 fai"l-
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.
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Adult females have smaller home ranges in years they have litters
of newborn cubs than in other years.Excluding such females from
the analysis,horne 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 aff·ect
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 cri ti·cal habitat importance to
brown bear populations in the study area.
None 9f 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.
ii
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 potential biases were
-identified in this estimate,most of these would tend to yield an
underestimate.Thi s procedure will be repeated in spring 1983
when a different array of sightabili ty biases would exist.The
possibility that emigrations of subadult b~ack 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 abundance.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.
iii
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 ourr_
hypothesis that ear~y 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 avail-
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.
iv
Radio-tracking data indicate 5 bears used identified sloug~
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
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are discussed.Addi tional work is required to determine the
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impacts of reduced salmon spawning in slough habitats on
downstream black bear popul"ations.
v
I I.TABLE OF CONTENTS
Page No.
I.
II.
III.
IV.
Summary
Table of Contents
List of Tables . . . . .
List of Figures
. i
.vi
. . . . . x
xiv
V.Introduction and Acknowledgements 1
VI.Methodology...................3
VII.
VIII.
The Study Area . . . . . . . . . . . . . . . ..6
Results and Discussion--Brown Bears 9
A.
B.
Downstream Brown Bears .
Upstream Brown Bears
• • • • . 9
. .... . . . .11
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1.Sex and Age Composition of
Study Animals . . ........11
vi
I I.TABLE OF CONTENTS
Page No.
2.Population Biology and
Productivity ...15'
3.Home Range Analyses . . . . . . ...'23
a.Home Ranges . . . . . . . .23
-.b.Seasonal Movements to Areas of
Food Abundance
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.27
4.Den and Denning Characteristics . . .28
IX.Results and Discussion--Black Bears . . . . . .33
A.Downstream Black Bears . . . . . . . . . .33
1.Introduction . .33
2.Sex and Age Composition of
Study Animals . . ........34
3.Food Habits of Downstream
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Black Bears
vii
. . .39
I I.TABLE OF CONTENTS
Page No.
a.Movements to Sloughs ..... . .39
b.Scat Analyses . . . . . . .42
c.Slough Inspection . . . . ...45
4.Home Range Analyses .. . . . .49
B.Upstream--Black Bears .52
1.Sex and Age Composition of
Study Animal s .........52
2.
3.
Black Bear Census
Home Range Analyses
.54
. . . . .60
4.Berry Abundance Analyses 64
5.Population Biology and
Productivity 67
6.Food Habits -Black and
Brown Bears
viii
. . . . . • •68
I I •TABLE OF CONTENTS
Page No.
7.Den and Denning Characteristics--
Upstream and Downstream . . . . . . .70
X.References . . . . . . . . . . . . . . . . . .76
XI.Appendices
-Appendix 1 Distribution maps for
individual bears in the
downstream study area .. .77
Appendix 2 Den entrance and emergence
data . . . .89
Appendix 3 Preliminary components of
brown bear model (not included)
Appendix 4 Preliminary components of
black bear model (not included)
ix
III.LIST OF TABLES
Page No.
Table 1~Brown bear capture statistics . . . . . . . . .13
Table 2.Brown bear relocation frequency . . . . . ....16
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Table 3.
Table 4.
Table 5.
Summary of brown bear cub and
yearling losses . . .
Pulses in brown bear cup production
indicated by harvest data . . . . .
Predicted 1983 reproductive status
of radioed brown bears·....
· . .18
21
· . .22
Table 6.Annual brown bear home range sizes . . . . . .24
Table 7.Characteristics of brown bear den
I~
sites
Table 8.Distances between brown bear den
sites in successive years ....
x
30
· . .32
III.LIST OF TABLES
Table 9.Black bear capture statistics
Page No.
. • . . . . .36
Table 10.Black bear relocation frequency--
downstream study . . .... . . .· ....38
Table 11.Bear scat analyses . . . . . . . .~. ....44
Table 12.Bear use of salmon spawning
Table 13.
streams
Fish abundance in and bear use
of downstream sloughs and
tributaries . . . . . . . . . .
· . . .46
.47
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Table 14.Downstream home range size--
black bears . . . . . . .51
Table'15.Black bear relocation
frequency--upstream study.. . . . . . . . . .53
Table 16.Upstream home range size--black
bears . . . . . . . . . . . . .
xi
· . . .61
III.LIST OF TABLES
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Page No.
Table 17.Berry abundance in transects ......•..67
Table 18.Predicted 1983 reproductive status
of radioed black bears . . . . . . . . . . . .69
Table 19.Black bear den site characteristics .....74
Appendix 2.
~,
Table A.
Table B.
Table c.
Table D.
Days in 1980/81 brown bear dens . . . . . . .90
Days in 1981/82 brown bear dens . . . . . . .91
Days in 1982/83 brown bear dens . . . . . . .92
Annual comparisons of brown bear dens
of entrance and emergence dates . . . .93
-Table E.Mean brown bear den entrances and
emergence dates by year . . .,.. . . . . ...94
.....
Table F.Days in 1980/81 black bear dens . . . . . . .95
xii
III.LIST OF TABLES
Page No.
Table G.
Table H.
Table I.
Table J.
Days in 1981/82 black bear dens . . . . . . .96
Days in 1982/83 black bear dens . . . . . . .97
Annual comparisons of black bear den
entrance and emergence dates . . . . . . . . .98
Mean black bear den entrances and
emergence dates by year . . . . . . . . ....99
xiii
IV.LI ST OF FIGURES
Page No.
,,-Figure 1.Downstream study area.(black and
brown bears).... . . . . . . . . . . . . . 7
Figure 2.Upstream intensive study area
(black bears). . . . . . . .. . . . . 8
,~
Appendix 1.
Figure 3.1982 home range of G379 78
Figure 4.1982 home range of B366 . . . . . . . . . . .79
.Figure 5.1982 home range of B367 80
Figure 6.1982 home range of B369 . . . . . . . . . . .81
Figure 7.
Figure 8.
1982 home range of B370
1982 home range of B372
....82
. .83
_Figure 9.1982 home range of B375 . . . . . . . . . . .84
xiv
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IV.LIST OF FIGURES
Page No.
Figure 10.1982 home range of B376 85
Figure 11.1982 home range of B377 . . . . . . . . . . .86
Figure 12.1982 home range of B378 . . . . . . . . . . .87
Figure 13.1982 home range of B365 88
xv
v.Introduction and Acknowledgements-
This progress report is an updated supplement to our Final Phase
I report (Miller ap.d McAllister 1982).The material discussed
here does not repeat analyses presented in.our earlier report
-i
except where additional information was collected in 1982 that
modifies or significantly strengthens the results presented in
that report.Also included in this report are the preliminary
results of studies initiated in 1982.This report is a supple-
-ment to our earlier report and does not present all the informa-
tion available about the proposed Susi tna project's impact on
bear populations.~
The dedication,talents and efforts of Dennis McAllister (ADF&G)
have been of crucial importance throughout all aspects of this
study.Valuable contributions were al so mad.e by K.Schneider,
W.Ballard,B.Taylor,N.Tankersley,SuzAnne Miller,J.Whitman,
D.Anctil,S.Albert,E.Goodwin,R.Smith,M.Chihuly,T.Otto,
P.Smith,and R.Sleeper (all ADF&G).S.Lawler,P.Miles and
r-V.Alexander provided cheerful clerical assi stance.
I
The skills of V.Lofstedt,C.uofstedt,M.Hauke,and D.Wilson
(Kenai Air Alaska)were appreciated in piloting helicopters and
fixed-wing aircraft as were the skills of A.Lee (Lee's Air
Taxi),K.Bunch (Sportsman's Flying Service),D.Deering (Deering
Air Taxi),C.Allen (Allen Flying Service),and several pilots
with Air Logistics Inc.Special thanks to Rick Halford (Susitna
Lodge),the Denali Mining Co.,and Jim Grimes (Adventures Unlim-
ited)for permission to use their landing strips and facilities
for storing fuel.Su-Hydro fisheries study personnel (ADF&G)
provided logistic support during our downstream bear study
effort.
The cooperation of Granville Couey (ACRES),the Watana Camp man-
ager and his staff was appreciated.Dr.Richard Taber and
r
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r
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Dr.Ken Raedeke (Univ.of Washington)made valuable suggestions
during their association with TES,several staff members of LGL
have also made valuable suggestions.
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VI.Methodology.
Methods presented in Miller and McAllister (1982)were continued
in 1982.Capture efforts in 1982 were made from 26 May through
11 June.Four black bears (including 2 yearlings)were captured
in dens in April 1982.'No mid-summer capture efforts were con-
ducted in 1982 except for a brief effort to snare bears in the
downstream study area on 30 August-4 September.Efforts to snare
bears and evaluate bear use of salmon spawning sloughs downstream
of Devils Canyon were conducted by riverboat out of Talkeetna.
The weather was generally cooperative in 1982 and flights to
monitor radio-collared bears were conducted on 4/19,5/4-6,5/18,
6/1, 6/9,6/11-12,6/17,6/24, 6/29,7/8-9,7/15, 7/26,8/3,
r 8/10,8/17-22 (census),9/8,9/20,9/24,10/6,10/15,10/20,
11/15,and 12/17.Some difficulty with weather was encountered
during the period of den entrance in fall 1982.
....
I
I
Locations of dens used in winter 1981/82 were located on the
ground and marked in early April and revisited for measuring in
late June.Dens used in winter 1982/83 have only been plotted
r-[from the air at this writing sO'these data should be considered
preliminary.
--Methods used in the new,components of thi s study initiated in
1982 are discussed along with the results of these studies (bear
densi ty estimate,bear food habi ts,berry abundance analysis).
3
CODE.
A.
B
C
D
E
F
Locations obtained in 1982 have been digitized and analyzed only
through 9 September,data collected subsequently are not included
in analyses.
The data file of all point locations collected to date was sup-
plemented in 1982 with a code for each location indicating my
interpretation of the bear's motive for having made the movement
from its previous location.This code will be helpful in plot-
ting seasonal home ranges.The codes utilized are listed below.
No specialized movement suspected
In seasonal activity area--caribou calving grounds
En route to or from caribou calving grounds
In seasonal activity area--salmon fishing area·
En route to or from salmon fishing area
In seasonal activity area--searching for food resources that
are scarce in that year within normal home range (especially
bad berry years)
G En route to or from above area
H In seasonal activity area--d.enning behavior outside of known
non-denning range
I En route to or from above denning area
J In seasonal activity area--generalized ~arly spring lowland
foraging
K Suspected di spersal movements
L Ini tial capture site or recapture site of non-radioed bear
M At or en-route to or from den site wi thin normal horne range
4
In similar fashion codes were added to the data file indicating
the reproductive status of the bear at each point location.
These data are not automatically collected because often the bear
was not actually s~en when radio-located.However,if,for exam-
~pie,the bear had offspring with it prior to and subsequent to a
location when it was not seen it is probable it also had them
during that location.These codes will be useful in isolating
movements of bear which may be related to reproductive status
(females with cubs vs.females with yearlings,subadult dispers-
....als,etc.).The codes utilized are listed below.
CODE
A
.~B
I
C
r D
E
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F
wi th nejlborn cubs
wi th yearling offspring
wi th 2-year old offspring
wi th 3-year old offspring
Presence or absence of offspring unknown (had them previ-
ously but not subsequently)
Probable or known estrus female or breeding male (usu~lly
-accompanied by another bear in the case of males)
G Inactive or unknown or alone-(cubs lost or weaned)
H Subadult
5
VI I.The Study Area
~1eupstream study area (impoundment vicinity)remained as dis-
cussed by Miller and McAllister (1982).In 1982,a downstream
study was initiated to evaluate bear use of salmon spawning habi-
tats and interchange between upstream and downstream populations.
In this downstream study,most bears were captured between Curry
and Portage Creek.Based on the movements of these bears,the
downstream study area is illustrated in·Figure 1 which encom-
passes an area of 1,157 km 2 •This area includes the movements of
11 black bears (B365,B367,-B369,B370,B372, B374, B375,B376,
B377,and B378)and one brown bear female with newborn cubs
(G379).One black bear (B365)moved out of the Susitna drainage
into the Chulitna drainage in 1982 and has not returned;exclud-
F ing this bear and the brown bear,the primary downstream black
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bear study area in 1982 encompassed 527 km 2 (Figure 2).
j )-1
,.
1II
1 --l J J J !
1Il
,~
r!J~
(!j
1Il,.
,.
llfllf
1Il llf llf,1II
1II
r!Jr!J
r!Jr!J
llf
1II
1IIlIIi.1II llf /llf
1II .....
1Il
1II
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Figure 1.Down.tre.m .tudy .re.(exten.lve).polygon enelo,e,1.167 .q.km.131 point'.(1 em =3 km)
1 1 ~i 1 j j )J J .~j
Figura 2.Downetream black baar Itudy .ra.(lntanllva).polygon anclo.a.tha 127 'Q.km u.ed by 10 r.dlo-collared black baar••
~17 point ••.(1 em =2.3 km)
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VI I I.Results and Discussion--Brown Bears
A.DOWNSTREAM BROWN BEARS
Only one brown bear was captured in 1982 in the downstream study
area.This bear (G379,a 5 year old female)had a litter of 2
newborn cubs which survived through the last visual observation
of this bear on 20 October.Subsequent to this sighting (near
the confluence of the Talkeetna River and Chunilna Creek)G379
moved and entered a den near Portage Creek (near the Susi tna
River downstream of Curry).This den has an approximate eleva-
tion of 1,550 feet,substantially lower than the mean elevation
of 4,181 feet (range 2,330-5,150)reported for brown bear in the
impoundment study area (Miller and McAllister 1982:67).
This downstream bear also did not follow the pattern of remaining
a·t high isolated locations reported for upstream brown bears with
Cl.lbs by Miller and McAllister (1982:57).In spring and early
.Sl.lmmer,thi s bear remained in relatively high open country but
from early August through late September she was found on the
Susitna River in the immediate vicinity of the sloughs and trib-
utaries used by spawning salmon-(Figure 3).In these areas,this
bl!ar probably had a higher probability of encountering other
brown bears fishing for salmon and subjecting her cubs to pre-
dation than would have been the case at higher elevations.This
behavior appears to contradict our speculation (Miller and
McAllister 1982:57)that female brown bears with cubs tend to
9
avoid areas where other brown bears concentrate.The behavior of
this individual may be aberrant,our earlier speculation may be
incorrect,or it may be that the salmon spawning sloughs utilized
b~{G379 and her cubs were relatively "safe"because they were
frequented by few other brown bears.During our examination of
the sloughs in the area used by G379,we found relatively little
,-
evidence of brown bear presence compared to sloughs farther
upstream (above the confluence of the Susitna and Indian Rivers).
Perhaps the areas where G379 fished was frequented by few other
fishing brown bears.Unquestionably,these sloughs were used by
many black bears,including radio-collared black bears.Unques-_..
tionably also,these sloughs were used by some brown bears as
brown bear fi shing for salmon in thi s area were frequently
spotted by local residents and by Su-Hydro personnel conducting
fisheries studies.It seems probable that the bear habitat down-
stream of the Indian River becomes progressively better for black
,-
bE!ars and poorer for brown bears and that the cubs with G379
WE!re,corresponding,safer fishing at these downstream sloughs
tllan they would have been at more upstream locations where other
-brown bears were more abundant or at Prairie Creek.Additional
speculation based on the behavior of one individual is not justi-
fied.It should be noted that thick vegetation prevented visual
observations of G379 or her cubs during the period 3 August
tllrough 15 October so it cannot be stated with certainty that her
~Ct~S were with her during this period,however,it is most prob-
able that they were.
10
Females with cub litters or yearling litters are commonly seen
fishing for salmon at McNeil River on the Alaska Peninsula
(Glenn,etc al.1974)but appear much more aggressive towards
other bears than femfl,les wi thout young (Egbert and Stokes 1974).
Efforts to increase the sample size of downstream brown bears
will be conducted in spring 1983.
-Maps of point locations for each individual radio-collared in the
downstream study area are presented in Appendix 1.
B.UPSTREAM BROWN BEAR STUDY
1.Sex and Age Composition of Study Animals.
S,ex and age composition of study animals in 1982 did not vary
significantly from that presented in Miller and McAllister
(1982).Three new upstream brown bears were captured and radio-
marked in spring 1982,one previously marked individual (0282)
was recaptured and radio-collared,and the radio-collar was
r,eplaced on a subadult male (G342a)first captured in 1981.
Initiation of capture efforts in 1982 was delayed until the clo-.-
sure of the spring brown bear hunting season on May 25.The
optimal period for capturing brown bears is earlier when snow
conditions are better for tracking and bears are more visible and
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in better condition..In 1983,the end of the spring hunting sea-
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slon has been extended to May 31.Capture efforts in 1983 will
nleed to be conducted during thi s spring season .in order to be
effective and efficient.
Ciapture statistics on all brown bears captured to date are given
in Table 1.r_
One marked brown bear (G332 at age 3)was shot by a hunter in
1982,the sibling of this bear (G333)was shot in fall 1981 at
age 2.A total of 5 marked brown bears have been shot by hunters
during the period of 1980-1982.
E:lghteen brown bears are currently radio-collared for Susi tna
studies.Two of these (G380 and G341)are missing probably
b€~cause of radio failure,unreported hunter kills,or movement
out of the study area.Two more brown bears (G293 and G342)are
wide-ranging bears seldom found in the primary study area.The
effective sample·of radio-collared brown bears is currently only
14,this must be increased to approximately 25 in spring 1983.
The two bears reported as missing by Miller and McAllister
(1982:18,21)were not found (G308a,G334)in this year of study.
In addition in.spring 1983 drop-off collars will be applied on
2··3 year-old subadul ts to obtain needed data on dispersal from
the study area.
12
--1 1 -1 ..~I -J j 1 j !'~
Table 1.Brown bears captured in Susitna Dam Studies as of November,1982
Capture
Tattoo Sex Ag~------.!'1h.__.l2at:e::-~__.F':tl!qu.eI1cy FlllgS _E.ar_Tags COllUllents
i I
I
i
11
see 8/6/81 recapture
collar shed by 5/4/80
w/2 ylgs,t~rgid ;
w/299,shot by hunter on 9/18/81
w/299
turgid
estrus?
w/338 ar.d 339
w/283 and 339,not drugged
w/283 and 338,not drugged
w/2c @0.5 -not captured
w/336
w/313,not drugged (abandoned)
wl.3c (2 captured subsequently not ear-tagged)reunited on 5/9/81
not estrus
w/F 341
w/M 280
w/2 @2.S (297 and 298 -not recaptured),not estrus
alone,see 3/25/82 recapture
w/2 cubs subsequently
turgid(?)-see 8/6/81 recapture
collar shed by 5/14/80
w/311
shot on 9/16/80
w/314 @2.5
w/313
alone
near 283 w/2c,shot by hunter on 5/18/81
w/332 and 333,died August 1982
w/331 and 333,shot by hunter on 9/5/82
w/331 and 332,shot by hunter on 9/3/81
w/33S,estrus
1303/1304
1109/1110
(130111302)
131811317
1319/1320
1126/1125
1096/1095
1117/1118
1312/.!lli
1119/1120
1049/1050
1127/1128
107411073
(129611295)
(1215/1216)
(1240/1239)
.1292/1291
1220/1219
1201/1202
108911090
1224/1223
1222/1221
1300/1299
1120/1119
1237/1238
1294/1293
1225/1218
1097/1267
1208/1207
1109/1110
1228/12271
1204/1203
white CF
white CF
white CF
white CF
white CF
white CF
white CF
red CF
white CF
white CF
red CF
white CF
1277)F 10.5 225*4710780 .._...orange 106571066 w/2 y1gs,not marked,collar shed 80781 den
(278)M 9.5 375*4/19/80 ------capture mortality
(279)M 9.5 400*4/20/80 orange 1100/1099 collar shed by 6/12/80
280 M 5.5 300*4/20/80 orange 1097/1098 reco11ar ne~t spring
(214)M 4.5 300*4/22/80 blue 1072/1071 collar shed 9/9/80
281 F 3.5 250*4/22/80 orange 16175/15950 not turgid
282 M 4.5 325*4/22/80 orange 1079/1080 see 6/82 recapture
283 F 12-.5 280·4/22/80 orange b'9OlbB9'""w2 @2.5:284 and 285
(284)M 2.5 180*.4/22/80 white 1074/1073 w/283 see 5/5/81 recapture
285 M 2.5 180*4/22/80 green 687/688 w/283
286 M 3.5 264 5/1/80 orange 1081/1082
292 F 3.5 174 5/2/80 green 1322/1321 Turgid
293 M 3.5 277 5/2/80 white 1116/1115
(294)M 10.5 .607 5/2/80 white
(295)M 12.5 589 5/3/80 green
299 F 13.5 285 5/4/80 green
(297)M 1.5 65 5/4/80 orange
298 M 1.5 65 5/4/80 orange
306 F 3.5 163 5/4/80 white
308A M 6.5 480 5/6/80 white
(308B)F 5.5 240 5/6/80 white
(309)M 12.5 600 5/6/80 orange
312 F 10.5 319 5/7/80 orange
(311)M 2.5 227 5/7/80 orange
313 F 9.5 286 5/7/80 orange
314 F 2.5 154 5/7/80 orange
315 F 1.5 90*·5/7/80 green
(284#)M 3.5 125 5/5/81 red CF
(331)F 6.5 172 5/5/81 white CF
(332)M 2.5 79 5/5/81
(333)M 2.5 67 5/5/81
334 F 10.5 325 5/5/81
335 F 2.5 194 5/5/81
281#F 4.5 --5/6/81
283#F13.5 261 5/6/81
338 M 0.5 12 5/6/81
339 F 0.5 13 5/6/81
312#F 11.5 280 5/6/81
313#F 10.5 2845/6/81
336 F 0.5 --5/6/81
337 F 13.5 321 5/6/81
340 F 3.5 190 5/6/81
280#M 6.5 394 5/7/81
341 F 6.5 224 5/7/81
299#F 14.5 291 5/7/81
342A M 2.5 220 5/7/81344F5.5 --5/8/81 __
i
.'j
(continued on-next-page)
)1 1 1 ))j ]1 )1 J B 1 »r
Table 1.Brown bears captured in Susitna Dam Studies as of Novelllber,1982,(continued)
Capture
Tattoo Sex Age Wt.Date Frequency Flags Ear Tags Comments
(345)M 7.5 495 5/8/81 ---.--capture mortality
(308B)#F 6.8 --8/6/S1 ------recapture mortality
299#F 14.8 --8/6/81 .white CF 1109/1110 collar replaced
.293#M 4.S --8/6/81 red CF 1115/1116 collar replaced
(294#)M 11.S --8/6/81 red CF ----recapture Ili0rtal1ty
347 M 14.8 500*8/6/81 red 1234/1233 collar shed 9/81
342A#M 3.5 250*5/25/82 i red CF 1228/1227 collar replaced
373 M 9.5 450*6/11/82 ------no tattoo,w/G283 (F)
282#M 6.5 350*6/11/82 ;whi/red 529/1643 recapture of marked bear
379 F 5.5 300*6/11/82 ~hite Er,CF 1595/1585 w/2@C,Downstream study
380 F 15.5 275*6/12/82 .white Er,CF 1588/532 w/2@1,not captured
381 F 3.5 200*6/12/82 .'white EF ,CF 533/1592 alone
*Weight estimated,()indicates shed collar or dead bear,#recapture,collar or ~ark replaced subsequently
I~
2 .Population Biology and Productivi ty
Simulation models under development attempt to track project
impacts on bear populations through changes in producti vi ty on
the premise that project-related changes in food abundance or
availability will be expressed by changes in productivity (along
with changes in dispersal patterns).Better data on productivity
population biology and dispersal are crucial to realistic use of
these models.Such data are inadequate at present..
--
In the period 1978-1982,28 newborn cubs in 13 litters were spot-
t,ed with radio-collared females'early in the spring,this pro-
vides a minimum estimate of initial litter size of 2.15 cubs/lit-
t,er (range =1-3).Initial litter size may be actually larger as
,-some mortality doubtless occurs prior to emergence as well as
prior to initial spotting following emergence.Ten of these lit-,-
tiers (with a total of 21 cubs)were successfully followed
throughout their cub year and 9 cubs were lost in this period .....,
This yields a cub mortality estimate of 43%(Table 3).
....
15.
~~,
Table 2.Number of point-locations of radio-collared brown bears for Su-Hydro studies,1980-1982.
-Year of
initial No.of radio-No.River
Bear capture locations Crossings
10 (age)1980 1981*1982 1980 1981 1982 Comments
~MALES
342A 1981 (2)8 16 1 0 Active,moved downstream
293 1980 (3)8 11 12 2 0 1 Active,wide-ranging
214 1980 (4)11 0 Collar shed,originally
captured in 1978
280 1980 (5)10 24 16 2 10 3 Active
308A 1980 (6)4 0 Missing**
282 1982 (6)18 6 Active
373 1982 (9)11 3 Active
279 1980 (9)2 0 Collar shed
294 1980 (10)14 8 1 0 Recapture mortality
295 1980 (12)2 1 Collar shed
309 1980 (12)3 0 Collar shed
347 1981 (14)-.4 0 Collar shed
All Males """5T 5'5 7""3 6 -11 --r3
FEMALES
335 1981 (2)34 19 0 0 Active
281 1980 (3 )13 40 21 1 6 5 Active
340 1981 (3)39 22 6 8 Active
381 1982 (3 )17 4 Active.-308B 1980 (5)15 13 5 7 Recapture mortality
344 (w/2c 1981)1981 (5)21 21 0 0 Active
379 (w/2@c,r82)*1982 (5)19 1 Active
331 (w/2c 1979)1981 (6 )24 9 4 3 Died in Aug.182
~341 1981 (6)28 8 9 0 Missing**
313 1980 (9)14 24 21 0 0 0 Active
277 (w/2 ylg 1980)1980 (l(i)6 0 Collar shed
312 (w/2c 1981)1980 (10)12 24 19 0 0 0 Active
334 1981 (10)31 0 Missing**
283 (w/2c 1981)1980 (12)12 19 19 0 0 4 Active
299 (w/2 ylg 1980)1980 (13)10 23 20 2 2 2 Active
337 (w/3c 1871)'1981 (13)19 19 0 0 Active
380 (w/2@ll 1982 (15)17 0 Missing**--All Females ~""'TI9 """"2'U 8 ---'3'4 ---,:r
TOTAL BOTH SEXES 136 394 315 14 45 40
Observations of unmarked bears 24 32 56
TOTAL m 416 nr Ir 45 """"40
~*G379 is in downstream study area,G342a also in 1982.
**Possible unreported hunter kill,collar failure,or emigration
-
-
The timing of cub losses is significant to productivity because
females that loose whole litters prior to or during breeding sea-
son may breed and produce a new litter the following spring.Of
the 9 cubs lost (T~ble 3)5 were lost in the spring (between May
9 and June 17,one of these may have been capture-related),one
was lost between 4 August and 1 September and 3 were apparently
lost in their winter dens.In only one case was a complete lit-
ter lost (G313,'with a litter of 1 cub lost by May 9),·this bear
produced a new litter the following spring (1982).G299 also
lost her litter of 1 cub in.spring 1982 and may produce a new
li tter in spring 1983.
The reasons for cub losses are unclear but predation by male
bears is considered a probable maj or factor.The condition of
the mother,likely related primari ly to food avai 1abi li ty,may
also contribute to these losses.Most cub losses during thi s
study occurred in 1981,a year of suspected widespread berry
failure (Miller and McAllister 1982),however,half of the cub
losses observed in 1981 occurred prior to this berry failure.
The other 2 losses occurred during or aft~~the berry crop condi-
tion was appare~t to the bears and may have been influenced by
this factor.
In simi 1ar fashion,mean size of 20 litters of 32 yearlings
observed in the spring was 1.6,26%less than the mean size of
observed cub litters.Four of 14 yearlings (29%)observed
throughout 'their yearling year have been lost,all in 1982
17
Table 3.SUllUnary of known losses from brown bear litters of cubs and yearlings,(dated from emergence
in year of birth to emergence the following year).
r::r~.
Year of emergence
1978
1979
1980
1981
1982 (through Oct.)
TOTALS:
Losses of cubs
2 of 3 lost (1 litter,207)
2 of 3 lost (1 litter,321)
No data
4*of 16 lost (312,313,283,
337,344)
1**of 5 lost (299,313,379)
9 of 21 lost =43%
Losses of yearlings
o of 3 (2 litters 221,220)
o of 1 lost (1 litter,207)
o of 4 lost (2 litters,299 and 277)
No data
4 of 6 lost (312,283,336,344)
4 of 14 lost -29%
•
*One possibly capture-related from litter of 1 with 313
**From litter of one with 299 •
(Table 3).Of the lost yearlings,one was lost prior to May 18,
2 were lost prior to June 17,and one prior to July 26.G344
lost one of her yearlings in June and the remaining yearling in
July;this bear then apparently bred and may produce a new litter
in winter 1982/83.G283 also lost her litter of one yearling (by
May 18),and may have a new litter this winter.G337 lost only
one of her 2 yearlings in 1982,so will not breed again until
1983.These data are interesting as they may reflect the impact
of the bad 1981 berry crop (Miller and McAllister,1982)on year-
ling survival the following year.No losses from yearling li t-
ters were observed prior to 1982 (Table 3).
As an initial working hypothesis for simulation models it will be
assumed that spring food availability does not affect survivor-
ship of cubs but summer food availability does.Both spring and
summer food availability affects survivorship of yearling and
older bears.
If the above working hypotheses is correct,poor spring food
availability (or poor summer food availability in the preceding
year)should result in losses of litters,females that lose these
litters should breed again and produce cubs the following year (2
years after a summer food failure or 1 year after a spring food
failure).If this hypothesis is correct,twice as many females
should produce cubs 2 years after a summer food failure than
would have been expected under "normal"conditions of food avail-
abili·ty.Under "normal"circumstances,approximately a third of
19
.~
the adult females would produce a new litter each year.
.~-<'-
Such
-
pulses in cub production may be self-perpetuating on a 3 or 4
year cycle as a pUlse of females born in year x produces their
own first litters in year (x+4)or as adult females that produced
a pul se in year x produce another pul se in year (x+3).Some evi-
dence for such pulses is apparent in the harvest data (Table 4).
Addi tional evidence for such pulses may become available from
radio-collared females in 1983.Of 13 radio-collared females 1 7
(54%)are expected to produce litters of cubs in 1983 (Table 5).
Of these 7 1 four are expected to produce litters because their
litter of cubs (G299)or yearlings (G344 and G283)were lost"in
1982 (Table 5).These predictions are consistent with the hypo-
thesis that a pulse of cubs will be produced in 1983 1 2 years
after the apparent berry crop failure in 1981 (Miller and
McAllister 1982).This hypothesis is significant to the project
as it is expected that the project will adversely affect spring
food availability and this would likely affect the productivity
of the bear population.
Miller and McAllister (1982:30)reported a reproductive interval
of 3 years in the 3 cases where a reproductive interval has been
observed in this study.G299 produced cubs in 1982 expanding the
number of known 3-year intervals to 4.G331 did not produce cubs
in 1982 1 as would have been expected if this bear was to maintain
a 3 year reproductive interval (she weaned a 2-year old litter in
1981 and bred).This 7 year-old bear died of "unknown causes in
July 1982.
20
-Table 4.Year of birth of subadu1t brown bears harvested in GMU 13.1969-19B1
data <includes sex unknown bears).
Year of No.harvested by age when harvested Totals Totals Totals
Birth Yearling 2 3 4
1-4 (%)2-4(%)1-3 (%)
~
1965 1
1966 3 1
1967 0 2 9
196B 2 4 8 6 20 (7)18 (7)14 (6)
1969 6 14 13 5 38 (13)32 (13)33 (l4)
1970 7 8 7 6 28 (9)21 (8)22 (10)
1971 2 6 6 13 27 (9)25 (10)14 (6)
plm~1972 1 14 6 3 24 (8)23 (9)21 (9)
1973 10 15 8 5 38 (13)28 (11)33 (14)
1974 4 12 2 4 22 (7)18 (7)18 (8)
1975 8 9 6 8 31 (10)23 (9)23 (10)
1976 5 18 5 11 39 (l3)34 (14)28 (12)
1977 2 10 11 8 31 (10)29 (12)23 (10)
1978 8 17 14 NA
1979 11 24 NA NA
1980 6 NA NA NA
~Totals 47 110 n 69 298 (100l 251 (100)229 (100)
(1968 -177)
r Table 5.Predicted spring 1983 reproductive status of radio-collared female brown bears.
10 1983 age expected 1983 Status Comments
~281 6 cubs first litter
335 4 cubs first litter,bred in 1982
340 5 cubs first litter
381 4 cubs first litter
344 7 cubs?lost yearlings in July 182 and bred
283 15 cubs lost ylgs in spring '82 and bred
299 16 cubs lost cubs in spring 1982
379*6 yearlings had cubs in 1982
313 12 yearlings cubs in 1982
341 (missing)9 yearlings (?)radio failure in 1982?
312 13 2-year olds yearlings in 1982
337 15 2-year olds yearlings in 1982
380 (missing)16 2-year olds radio failure in 1982?
(iiWff!,'*bear occurs in the downstream study area.
-
3.Home Range Analyses-Brown Bear
a.Home Range s :
Miller and McAllister (1982)observed that home ranges of radio-
collared brown bears were larger in 1981 than in 1980 and hypoth-
esized that bears might have had to range farther in 1981 because
of the apparent poor berry crop in that year.If this is cor-
rect,1982 home ranges should be smaller than 1981 home ranges as
berry crops appeared about average in 1982.This pattern was·
observed (Table 6)although the differences are not statistically
'.
significant because of the huge variation between individuals
(23-2,478km 2 in 1982,Table 6).
More insight into this hypothesis can be gained by examination of
the home range sizes of the same individuals in these 2 years,
al though sample size becomes small in this analysis.Twelve
-
individuals had adequate locations (n )74)to calculate home
ranges in both 1981 and 1982 (Table 6).Since 1982 home ranges
have been calculated for points only through 8 September 1982,
comparisons should be made with the equivalent period for 1981
(see Table 13 in Miller and McAllister 1982).By this analysis,
1982 home ranges (through 8 September)were smaller than 1981
home ranges (through 1 September)for 6 individuals (342,280,
335,281,313 and 299),larger for 5 individuals (340,344,312,
283,and 337),and the same for 1 individual (home range for G293
was only 3%smaller in 1982 than in 1981).The mean decrease was
61%(37-77%)and the mean increase was 91%(14-310%).
23
~j )J ,j j J J j j I 1 1 1
Table 6.Annual home range sizes for Su-Hydro study area brown bears.(Includes individuals with 5 or more relocations).
1980 1981 1982*
Bear ID Observation Period Home Range Observation Period Home Range Observation Period··Home Range
(age @ capture)(No.of locations)(km 2 )(No.of locations)(km 2 )(No.of locations)(km2 )*Comments
MALES
342a (2)------May-Oct (8)1776 May-Jul (11)690 dispersed in 181
293 (3)May-Oct (8)1409 May-Sep (11)2727 Jun-Aug (12)2578 wide-ranging
no den
214 (4)April-Sep (11)975 ------------ ---
shed collar in 180
280 (5)April-Oct (10)499 April-OCt (24)570 May-Aug (14)268
282 (6)----------------Apr-Sep (11)1156
373 (9)----------------Jun-Sep (9)566
294 (10)May-Oct (14)495 May-Aug (8)100 recapture mort.in 181K(all males)=110:8)845 (TI:'8)1149 TIT:4T 1052
S.D.=--439 --965 --911
range =(8-14)495-1409 (8-24)100-2727 (9-14)566-2578
FEMALES
335 (2)------May-Oct (34)180 May-Sep (16)96 weaned in 1981
281 (3)April-Oct (13)189 April-Oct (40)368 May-Sep (17)88 single
340 (3)------May-Oct (39)613 May-Sep (17)701 single
,
381 (3)------------Jun-Sep (13)224
30Bb (5)May-Oct (15)142 May-Aug (13)110 ------recapture mort.in 181
344 (5)------May-Oct (21)270 (w/2c)May-Aug (16)385 (w/2@1***)
379 (5)------------'Jun-Sep (12)58 (w/2@C)
331 (6)------May-Oct (24)1281 May-Sep (19)1216 weaned 2@2 in 181
341 (6)------May-Oct (28)889 May-Jul (8)23 (w/2@C)
313 (9)May-Oct (14)82 Apr-Oct (24)196 May-Sep (16)57 (w/2@C in 1982)
277 (10)April-Oct (6)147 (w/2@1)------------shed collar 1n den
312 (10)May-Oct (12)140 Apr-Sep (24)181 (w/2c)May-Sep (15)241 (w/l@l)
334 (10)------May-Sep (31)111**------weaned 1@2 in 181,missing in 182
(continued on next page)
1
Table 6.(continued)
J 1 1 •1 I J )j ~I
1980 --- -1981 1982*
Bear ID Observation Period Home Range Observation Period Home Range Observation Period Home Range
(age @ capture)(No.of locations)(km 2 )(No.of locations)(km 2 )(No.of locations)(km2 )*Comments
283 (12)April-Oct (12)233 May-Oct (19)93(w/2c)**May-Sep (15)205 (w/l@l****)
299 (13)May-Oct (10)188(w/2@1)Apr-Oct (23)358**May-Sep (16)81 (w/l@C****)
337 (13)------May-Oct (19)270(w/3c)**May-Sep (14)349 (w/2@1)
380 (15)------------Jun-Aug (8)284 (w/2@1)
x (all females)=""(II:'7f -rnr--m:rr~-m:u --
S.D.=48 --353 --323
range =(6-15)82-233 (13-40)93-1281 (8.19)23-1216
x (all males and females)=(11.4)409 (22.9)594 (13.6)488
S.D.=--422 --720 --616
range =(6-15)82-1409 (8-40)93-2727 (8-19)23-2578
*1982 relocation data nave been compiled only through September 8,subsequent relocatIons-including 1982 dens will
change these results.
**Not included in statistical comparisons
***Yearlings lost in July
****Yearlings or cub lost in May
..
.-
,~
.....
These data are confounded by the reproductive status of females,
females with cubs appear to have smaller home ranges when they
have cubs than when they do not (Miller and McAllister 1982).Of
the 5 bears that l!ad larger home ranges in 1982 than iIi 1981,
four (344,312,283,and 337)had cubs in 1981 so their increased
1982 home ranges can be explained on this basis.Of the six
bears with smaller home ranges in 1982 than in 1981,one can be
explained because of the presence of cubs in 1982 (G~13 with a
71%decrease in home range size in 1982 relative to 1981).
Therefore,excluding individuals with cubs in either 1981 or
1982,5 individuals had smaller home ranges in 1982 than in 1981
(mean=59%decrease,range=37-77%)and one had an increased home
range (+14%).This analysis supports our hypothesis that annual
home range size may be a function of the distribution and abun-
dance of food in any year.It also supports our hypothesis that
females with cubs have smaller home ranges in years they have
litters of newborns than in other years regardless of food avail-
ability .
This analysis combined with our earlier observation that females
with newborn cubs tend to remain more distant from the areas that
will be most impacted by the proposed project relative to other
bears (Miller and McAllister 1982)suggests that the proposed
project will have minimal direct impact on cub survival during
the cub's first year of life.As mentioned elsewhere,however,
the project will likely affect yearling and subadult survival
26
-
.~,
(through reducti,on of spring food availability)and may also
affect the probability or frequency with which adult females have
cubs (also through changes in spring food availability).These
F~
data suggest that adult brown bears may be able to compensate for
~.~changes in the availability of important summer foods (primarily
berries in this analysis)'by increasing their range of movements.
b.Seasonal movements to areas of food abundance:,During salmon
spawning season some brown bears in the study area make di rec-
tional movements to salmon spawning streams.Prairie Creek is
the most interior of these streams and 4 radio-marked bears moved
to this area in 1980 (of 11 with active collars)and 2 in 1981
(of 18 with active collars)(Miller and McAllister 1982:50).In
1982,the two individuals still radio-collared that had been pre-
"""viously observed making directional movements to Prairie Creek
did so again.Three newly collared bears (G282,G3 73,and G380
also moved to Prairie Creek.Therefore in 1982,of 14
radio-collared upstream brown bears 5 utilized the Prairie Creek
salmon resources.G293 repeated the same large movement
-previously recorded from the upper Oshetna to Prairie Creek.It
is interesting that G283 went to Prairie Creek in 1980 (after
~
weaning her litter of 2-year old offspring)but not in 1981 (when
she had a litter of cubs).In 1982 this bear lost her surviving
yearling in May and again revi si ted Prairie Creek in August.
None of the radio-marked bears that had no previous hi story of
visiting Prairie Creek (N=8)visited it in 1982.-
-
27
One male bear (G342)dispersed from the impoundment study area in
spring 1981 as a 2 year old,but foraged for salmon on the lower
Susitna in late summer 1981,and denned near Chuni1na Creek.In
spring 1982 this b~ar moved to the Kashwitna River but returned
to the Chuni1na Creek-Talkeetna River confluence in fall1982,
perhaps to fish for salmon.
As discussed earlier,the only brown bear marked for the down-
stream study (G379 with 2 cubs)frequented the salmon sloughs
along the lower Susitna (Between Curry and Indian Creek)during
the salmon spawning period.
4.Den and Denning Characteristics--Brown Bear
•
Characteristics of dens used in winter of 1980/81 by 13 radio-
collared and 3 unmarked brown bears were reported by Miller and
McAllister (1982:67).These data along with characteristics of
dens used in winter of 1981/82 by 13 radio-collared and 2
unmarked bears are given in Table 7.These data include 2 dens
(#37 and #36)in the Chuni1na Creek area,downstream of the
Devils Canyon damsite.Den sites in both years were located for
the following individuals:283,-313,337, 344,312,299,281,and
280.Tentative locations for the dens of these same individuals
were located in 1982/83.
28
i~
Mean elevation of these 31 dens was 4,117 feet (range 2,075-5,150-feet,SD=832 feet).Excluding the 2 downstream dens the mean
elevation of 29 upstream dens was 4248 feet (2330-~150 feet,
SD=683 feet).None of the brown bear dens observed to date would
be inundated by the proposed impoundments,including those tenta-
tively located during winter of 1982/83.
To date,no radio-collared brown bear has re-used the same den
~
site.However,many brown bears in the study area tend to den in
,-the same general area in successive years (Table 8).One of the
most popular areas for radio-collared bears is'in the mountains
,,~
between upper Tsusena and upper Deadman Creeks,near the Denali
access route and the upper Tsusena borrow areas.One bear (G281
""...
a subadult female)has denned in this area in 3 successive years
even though her home range during non-denning periods is some
distance away (Fog Lakes-lower Watana Creek)(see Figure 15 in
Miller and McAllister 1982:158).
/'!~.
29
-J J I 1 j I )}i .~•I I )1 J
Table 7.Characteristics of brown bear dens in the Susitna study area during winters of 1980/81,1981/1982.
ENTRANCE CHAMBER Total Previously
Den Bear Age at Elevation Slope Aspect Ht.Width Ln.Width Ht.Length Used?
No.ID No.Exit (Feet)(Degrees)(True N.).Vegetation (cm.)(em.)(cm.)(cm.)(em.)(cm.)(Yes/No)Comments
DUG DENS
FEMALES
With offspring (@ exit)
w/2 cubs 14 G283 (sp.)13 3900 28 192 Tussock grass -83 -138 -196 No Spring den/collapsed
w/2 cubs 16 G283 (wt.)13 3725 26 210 Willows 76 64 239 203 92 291 No Winter den
w/l cub 22 G313 10 5150 35 166 Tussock/rock slide - --104 -410 No Collapsed
w/3 cubs 24 G337 13 4825 31 252 Tussock/lg.rocks 57 69 -152 90 219 No
w/2 cubs 30 G344 5 4760 -153 --- - -- -
--Collapsed/not visited
w/2 cubs 31 G312 11 4900 -145 Tundra/rock - -
--- --Collapsed/not visited
w/2 ylg.*25 G277 11 4925 45 93 Moss/rock slide - --165 -207 No Collapsed
w/2 @2yr.28 G299 14 4660 25 138 Tundra/rock ------No Collapsed
w/2 cubs 42 .G331 7 3950 30 213 Willow,Grass 67 52 117 127 84**290 No Collapsed
w/2 cubs ·44 G313 11 4575 34 .,182 Grass 102**----230 No Collapsed
w/l ylg 47 G312 12 4925 27 201 --- - -----Collapsed
w/2 ylg 52 G344 6 4250 26 202 Grass 49 65 - ---No Collapsed
w/2 cubs 54 G341 7 4575 45**118**---- -----Collapsed/not visited
w/l cub 59 G299 15 3525 ~l 156 Willow,Alder 58 69 151 136 101 350 No
w/2 yrl 37***? ?207,5 36 346 Alder 53**79 -- --No Partially collapsed
w/o offspring 23 G281 4 4700 39 142 Tussock/rock slide -61 ----No Collapsed
w/o offspring 5 G308b 6 2330 26 358 Alder 69 82 112 112 110 230 No
w/o,offspring 46 G340 4 5150 -------- - --Not visited
w/o offspring 56 G335 3 3525 32 261 Willow,Alder 47 39 ---224 No Partially ~ollapsed
(continued on next page)
-j 1 1 1 J i i )I
Table 7.(continued)
ENTRANCE CHAMBER Total Previously
Den Bear Age at Elevation Slope Aspect Ht.Width Ln.Width Ht.Length Used?
No.lO No.Exit (Feet)(Degrees)(True N.)Vegetation (cm.)(cm.)(cm.)(cm.)(cm.)(em.)(Yes/No)Comments
MALES
1 G280 6 3950 32 158 Tundra/grass/rock 48 86 -231 -269 No Collapsed
15 G284?3 3990 23 216 Tundra/grass 56 83 135 154 77 239 c No 10 uncertain
29 G294 11 2650 30 146 Alder/grass 52 80 -157 89 188 No Partially collapsed
36***G342A 3 2375 31 288 Alder 38 71 81 86 94 124 No Partially collapsed
60 G280 7 4125 26 210 (irass,Willow - - ----No Collapsed
DUG DENS
UNKNOWN SEX/ID
17 - -
3925 33 192 Willow 61 62 154 162 122 220 No
26 --4090 29 162 Willow/grass 73 65 -- -
171 No Partially collapsed
27 - -
4125 26 140 Willow/grass -58 --68 -No Partially collapsed
53 ??4350 31 195 Grass - - -
,---No Collapsed
UNKNOWN CAVITY TYPE
w/l yrl 41 G283 14 4000'26 161 ---- - - ---Not visited
.w/2 @2 48 G337 14 5050 45**253**---------Not located
45 G281 5 4575**25 176 Grass -- - - ---Not located
*Entered den with 2 yearlings,shed collar in den;so exit not observed.
**Approximate value
***Downstream -Chunilna Ck.
Table 8.Distances between den sites (miles)used in different years by radio-collared
brown bears.
Distance between dens during winters of:Mean
Bear ID Sex Age*1980/81-1981/82 1980/81-1982/83** 1981/82-1982/83**
G283 F 13 3.2 2.4 5.2 3.6
G313 F 10 4.4 4.7 7.8 5.6
G337 F 14 3.6 2.6 3.7 3.3
G344 F 5 3.1 1.6 1.5 2.1
~
G3l2 F 11 2.1 0.5 1.7 1.4
G299 F 14 8.9 6.4 3.2 6.2
~
G28l F 4 1.9 1.7 0.2 1.3
G280 M 6 8.1 6.2 2.2 5.5....G335 F 3 2.1
G340 F 4 0.3
....G342 M 3 NA
x=4.4 3.3 2.8 3.4
*Age at exit of first den found
**1982/83 den locations are preliminary,based on aerial locations.
-
IX.Resul ts and Discussion--Black Bears
A.DOWNSTREAM STUDY --BLACK BEARS
1.Introduction
The primary emphasis in the downstream study area is to evaluate
bear use of salmon spawning in the sloughs and tributaries likely
to be affected by altered flow regimes subsequent to project con-
.-struction.If salmon are less available to bears subsequent to
-
the construction,this is likely to affect bear distribution and
abundance in the Susitna watershed between .Talkeetna and Devils
Canyon.Changes in successional status of forage resulting from
altered frequency of flooding may also affect the quality of bear
habitat in riparian areas,some insight into these impacts will
likely come from vegetation studies being conducted as part of
downstream moose studies.As an incidental result of these down-
stream bear studies information on the relationships between
downstream and upstream bear subpopulations will also be
gathered,this information will be helpful in evaluating the con-
tributions,through dispersal,that upstream black bears (expec-
ted to be heavily impacted by the project)make to surrounding
subpopulations.Miller and McAllister (1982:10S,111)noted
movements of upstream black bears to downstream areas in the
vicini ty of salmon spawning sloughs during 1981,a year of
apparent widespread berry failure upstream,and speculated that
the downstream area may serve as an important buffer zone for
33
upstream bear populations during these conditions.The project
may reduce the effectiveness·of this zone to buffer upstream
black bear populations.
Loss of slough habitats for salmon spawning may reduce salmon
availabiltiy to bears even if salmon spawning is maintained in
the mainstem Susi tna by mitigative measures if the physical
characteristics of the slough habitat,increase salmon vulner-
ability to bear predation relative to mainstem or tributary
habi tats.
Preliminary evaluations indicate that project-related impacts
downstream of Devils Canyon will affect more black bears than
brown bears because of the apparent relative greater abundance of
-black bears in the downstream study area.However resident down-
s"tream brown bears will likely 'also be affected by the same
mechanisms as black bears.In the downstream study area brown
bears appear to become progressively more abundant proceding
upstream towards'Devils Canyon,reduced water flow during summer
-(and corresponding impacts on spawning salmon)are anticipated to
become progressively more marked proceding upstream as well
('rrihey,pers.cornmun.).
2.Sex and Age Composition of Downstream Black Bears.
In spring 1982,11 black bears were successfully radio-collared
for downstream studies.Captured bears appeared to be in excep-
34
tionally poor condition,possibly because of poor nutrition the-preceding year,the the lateness of the capture period (3-4 weeks
after emergence from dens and just prior to greening vegetation),-
or both.As a probable result of this poor condition two black
""".bears (368 and 371)died durin.g downstream capture efforts.
Another radio-collared bear was killed by·a hunter (B366)in
"'"'August.The current sample of radio-collared bears for down-
stream studies includes 10 black bears (9 females and 1 male)and
1 brown bear (a female,age 5 with cubs).The black bear male is
_.age 5,the mean age of females in 1982 was 5.7 (3-9).The pre-
ponderance of females in the downstream-sample relative to
upstream black bears may reflect,in part at least,the heavier
hunting pressure in the downstream area which is accessible by
riverboat.Black bear capture statistics are given in Table 9.
-Number of point-locations for downstream radio-collared black
bears collected in 1982 are given in Table 10 .
.....
35
Table 9.Black bears captured in Susitna Dam Studies as of November,1982
Capture
Tattoo Sex Age Wt.Date Frequ(!ncY__F'lagfJ E:fir Ta.gs Comments
w/1 newborn &1 y1q shot by hunter 8/28/80
w/2 cubs ;
w/1 cub,also immobilized in den on 3/81
died summer 1981
shot by tunter 9/9/80
had 2 cubs in 1981
w/324,collar shed in 80/81 den,see 5/26/82 recapture
w/322 .•
collar shed in 80/81 den,see 8/6/81 recapture
w/2 cubs,shot by hunter 8/28/80
w/2 cubs,also immobilized in den on 3/81
w/303,had 2 cubs in 1981 I
recapture
w/327 and sibling,w/heavy collar
w/318,died summer 1981
cinnamon color,shot on 9/15/81
alone,Devil Mountain
alone,gaging station
alone,old collar previously shed
neck infected,collar not replaced
collar replaced,shed 6/82
old collar previously shed
collar replaced
collar replaced,shot on 9/8/82
alone,shot on 9/82
alone
recapture in den
recapture in den w/350 and 351
capture in den
capture in den
capture mortality
capture mortality of B301's yearling
w/2 cubs
w/354,no tattoo
w/354,no tattoo
1195/1196
1046/1045
1194/1193
1243/1244
1081/1088
1200/1199
1252/1251
1191/1192
1247/1248
1246/1245
1266/1265
1276/1275
1206/1205
1214/1213
1226/1184
1257/1105
1306/1279
1286/1316
1191/1192
1055/1056
(1083/1084)
1131/1132
1326/1325
same
same
514/513
516/515
red CF
white CF
red CF
red CF
red CF
white CF
'hite CF,EF 517/1600
518/519
520/521
red,CF,EF 501/1651
(287)M -10.5 225*571780 "_h white 108371084 Shot on 978782
(2BB)F 10.5 125*5/1/80 white 1095/1083 w/2 ylgs,turgid,collar shed by 8/27/80
289 F 9.5 130*5/2/80 white 1103/1104 w/2 ylgs,turgid,had 3 cubs in 1981
(290)F 8.5 103 5/2/80 blue 1306/1305 wl2 ylgs,turgid,see 8/6/81 recapture
(291)M (3.5)73 5/2/80 orange ---==-Post-capture mortality
(296)M (10.5)227 5/3/80 ---- --Capture mortality
(300)M (7.5)2745/4/80 orange -- --Post-capture mortality
301 F 7.5 115 5/4/80 green 1043/1044 w/l ylg,turgid,had 2 cubs in 1981
(302)M 8.5 287 5/4/80 blue 1106/1105 collar shed by 8/4/80
303 M 8.5 217 5/4/80 green lrn/l056 ----.
(304)M 10.5 235 5/4/80 I orange 1315/1316 collar shed in 1982
(305)M(9.5)217 5/5/80 .green --Shot by hunter 8/30/80
(307)M 2.5 105 5/5/80 orange 1123/1124 Shot by hunter on 5/17/81
310 M 2.5 85 5/6/80 blue/green 1122/1121
(316)F (12.5)150*5/7/80 blue
317 F 7.8 133 8/18/80 white
318 F 5.8 126 8/18/80 white
(319)M 3.8 174 8/18/80 orange
(320)M (4.8)200*8/18/80 orange
321 F 10.8 175*8/18/80 white
(322)M 4.8 154'8/19/80 orange
323 M 2.8 122,8/18/80 orange
324 M 5.8 190 8/19/80 orange
325 F 11.8 164 8l18/80 white
(326)F (5.8)125 8/19/80 white
327 F 5.8 118 8/19/80 white
328 F 6.8 150 8/19/80 white
303#M 8.8 260 8/19/80 orange
329'F 1.3 15*3/23/81 white
(330)M 1.3 31 3/25/81 orange
(342B)M (5.5)165 5/7/81 red CF
343 M 5.5 184 5/7/81 red CF
346 M 9.5 175*5/9/81 red CF
302#M 9.5 300*5/9/81 red CF
(290#)F 9.8 160+*8/6/81
(304#)M 11.8 --8/6/81
325#F 12.8 150*8/6/81
303#M 9.8 250*8/7/81
(287#)M 11.8 200*8/7/81
.(348)M 9.8 300*8/6/81
349 F 4.8 170*8/6/81
329#F 2.3 29 4/1/82
289#F 11.3 112 4/1/82
350 M 1.3 14 4/1/82
351 M 1.3 16 4/1/82
(352)M 2.5 100*5/26/82
(353)M 1.5 29 5/26/82
354 F 5.5 150*5/26/82
355 F 0.5 4*5/26/82
356 M 0.5 4*5/26/82
357 M 4.5 113 5/26/82----
i
1
1
I.~
I
i
I 1
~i l
(contInued on pext page)
lIt t i (l I L_l
Table 9.Black bears captured in Susitna Dam Studies as of November,1982,(continued)
Capture
Tattoo Sex Age Wt.Date ~equency.Flags _Ea~Tags _Comments
(322#)M 6.5 --~O*5727782 red CF,EF 16627525 recapture,previous shed collar,died summer '82
358 M 2.5 60*5/27/82 red cr,EF 50211656 ----
359 M 4.5 118 5/27/82 red CF,EF 51211655
360 M 7.5 250*5/27/82 red CF,EF.511/1657
361 F 7.5 175*5/27/82 white CF,EF 522/1596
362 F 2.5*40*5/27/82 --.5031504 no tattoo
3~3 F 4.5 120·5/27/82 white CF,EF 50511593
364 F 9.5 170*5/27/82 white CF,EF 52111591
365 M 5.5 100*5/28/82 red CF,EF 52311626 downstream ~tudy
(366)M 6.5 200·5/28/82 red CF,EF 53811627 downstream study,shot on 8/5/82
367 F 4.5 100*5/28/82 white CF,EF 524/1579 downstream study
(368)F 3.5 110*5/28/82 ----capture mortality
369 F 3.5*90*5/28/82 white eF,EF 52711578
370 F 7.5 220 5/28/82 white CF,EF 52811577
(371)M '2.5 150*5/28/82 ----capture mortality
372 F 9.5 135*5/28/82 white CF,EF 537/1576 ----
374 F 6.5 125*6/11/82 white CF,EF 530/1584 w/1@1,downstream study
375 F 5.5 160*6/11/82 white CF,EF 507/1630 w/3@1,downstream study ',,--
376 F 6.5 125*6/11/82 white CF,EF 531/1587 w/1@1,downstream study,see 9/2/82 recapture
377 F 5.5 126 6/11/82 white CF,EF 509/1659 downstream t>tudy
378 F 6.5 175*6/11/82 white CF,EF 510/1628 downstream study
376#F 6.7 160*9/2/82 white CF,EF ,530/1584 recapture,slough 8B,snare •
*Weight or age estimated,( )shed collar or dead bear,#recapture
~f i I I {t {(--l t_L._•'I
l _.•
Table 10.Number of point-locations for downstream radio-collared black bears for Su-Hydro
studies,1982.
Year of Initial No.of Radio-no.River
Capture locations crossings
Bear ID (spring age)1982 1982 Comments
MALES
365 1982 (5)11 0 Active,Chulitna River
366 1982 (6)10 1 Shot 8/6/82
ALL MALES 21 1
FEMALES
369 1982 (3)18 0 Active
378 1982 (3)14 0 Active
367 1982 (4)17 0 Active
376 (w/1@1)1982 (4)12 2 Active
i~375 (w/3@1)19'82 (5)16 5 Active
377 1982 (5)15 2 Active
~374 (w/1@1)1982 (6)3 0 Active
370 1982 (7)18 0 Active •
....;~72 1982 (9)17 0 Active
ALL FEMALES 130 9
TOTAl BOTH SEXES 151 10-Observations of unmarked Bears NA
TOTAL 151 10
~
3.Food habi ts of Downstream black bears.
a.Movement to sloughs
,-
~-
Results of radio-tracking·the single brown bear captured in the
downstream study area were reported ~arlier in this report.
Three methods were employed to evaluate bear use of salmon spawn-
ing areas in the 1982 downstream study:Location of radio-col-
lared bears,evaluation of use by bears of the salmon spawning
sloughs identified by fisheries subtask personnel,and analysis
of scats collected in the vicinity of the sloughs.A brief sum-
mary of the activities of each black bear during the salmon
spawning season follows.
B366 was not seen on any sloughs but apparently fished along
the main banks of the Susi tna River.Thi s bear was shot
near Curry in August.
B367 was found on slough 19 on 10 August.
B369 was not found on any sloughs or on the River,remained
close to the Susitna River 18-22 August.
B370 was not found on any sloughs but was found near the
mouth of the Indian River in early August.
39
-
-
--
.....
B372 was not found on any sloughs or on the mainstem Susitna
but did move close to Byers Lake (Chulitna drainage in early
September),perhaps to fish in this area.
B375 extensively fished the mainstem islands in late August,
on Portage Creek in early August and was found near sloughs
8B,8C and 8D in early August.
B376 clearly used slough 8B on 9/2/82 as it was recaptured
there in a snare,this is the only location on this slough.
This bear also spent a lot of time fishing on the mainstem
and islands in the vicinity of slough 8A in mid-late August.
B377 used slough 8A throughout August as well as the nearby
mainstem Susitna.
B378 was found in the vicinity of slough 8B in late August.
B365 was captured by the Indian River but moved north of the
Chuli tna River to the Hidden River drainage and Eldridge
Glacier area.It moved to lower Troublesome Creek during
salmon spawning but never returned to the main Susitna
drainage .
Li ttle data was collected for B374 because of a radio-
tracking malfunction.
40
.,~
Of the 9 radio-collared black bears that remained in the vicinity-of the Susitna during the salmon spawning periodl 5 (367 1 375 1
376 1 377 1 378)were radio-located on or in the immediate vicinity
of identified salmon spawning sloughs during the salmon run in
,~""August.Of the remaining bears l 2 (B366 and B370)were found
close (0-0.2 kIn)to the mainstem Susitna or its tributaries l
another (B369)was not found in a location that clearly suggested
fishing activity (but was found several times during August
within 0.3 kIn and 500 feet elevation from the mainstem Susitna)1
and the remaining bear (B372)was not found on the Susitna during
salmon spawning but did move to a tributary of the Chulitna where
salmon are abundant.Another bear that moved out of the main
study area in early spring (B365 1 a 5 year old male)was found
on Troublesome Ck.(a salmon-rich tributary of the Chulitna)
during salmon spawning.The movements of all radio-collared
bears l except possibly B369,are consistent with an explanation
that they were attracted during the salmon spawning period to the
salmon spawning sloughs 1 to the mainstem Susitna l to tributaries
of the Susitna or Chulitna Rivers l or to combinations of these.
Since none of these bears were initially captured on the salmon
spawning sloughs l these observations suggest a very high
incidence of use of salmon by resident black bears in the
downstream study area.Radio-tracking data of thi s type is
likely to underestimate use of salmon spawning sloughs by fishing
bears.Frame (1967)noted that black bears were most active in
fishing for salmon in Prince -William Sound at dawn and for
41
"""
-
-
-
several hours before and after dusk.In illustrations of this
probable bias,B376 would have had no point locations on slough
8B had it not been recaptured there in a snare set overnight.
b.Scat analyses
Bear fecal samples were collected along the sloughs during late
August and early September.Scats were analyzed by Paul Smith
(ADF&G,Soldotna)following procedures developed for his analysis
of black bear scats on the Kenai.In his technique,scats were
weighed,rehydrated,washed through nested sieves (#5,#25,and
#30),and the percent volume of each food item was estimated
(Smith per.comm.).I lumped items thought to have been inci-
dentally ingested by the bears (typically leaves and stems of
berry plants,wood chips ingested while searching for ants,or
soil)in the "other"category in Table 11.Scats were initially
collected during capture operations (known species of bear)or
picked up on the ground during other activities (unknown spe-
cies).Scats picked up by Plant Ecology subtask personnel are
identified by "Helms"in the comments column.Only fresh samples
(less than 2 weeks old)were collected,samples were frozen prior
to analysis.Portions of scats were retained for subsequent
identification of the species of bear dropping the scat using
thin-layer chromatography techniques that are still under
development (Miller and McAllister,1982 Appendix 6).Food items
present in these samples are presented in Table 11.
42
The low frequency·of identifiable.salmon remains and the high
.--'-
frequency of berry remains in scats are remarkable in these data
and appear inconsi stent with the large number of salmon we
observed that had been captured by bears as evidenced by the
presence of salmon carcasses carried away from the sloughs and
eaten by bears.
include:
Explanations for this apparent discrepancy
-
""'",
1.
2.
There is no discrepancy,salmon form·a small portion of the
summer diets of bears in thi s area.
Salmon remains are not identifiable in the scats because of
high digestibili ty relative to berries.
3.Bears use both salmon and berries on a daily cycle that
makes it unlikely that salmon-rich feces will be found on
the salmon spawning areas.
Addi tional work·will be required to identify which of these
explanations is correct.Of the berry species found in the fecal
samples collected to date it appears that devils club (Oplopanax
horridus)is an important late summer food item in the downstream
,-study area (Table 11).devils club was a common plant in
riparian areas near the sloughs and along the mainstem Susitna,
-its abundance distant from the river was not evaluated in 1982.
Fish were found in only 2 of the 7 samples collected in salmon
spawning sloughs in late August (Table 11).
43 -
)J I J J ])l J J )J J 1 J }
Table ll.Scat analyses of brown bear and black bear scats collected in the Su-Hydro study area,1980-1982. (Analyses done by Paul Smith,ADF&G,
Soldotna)•Values are %volume (T=trace,2=6-25%,3=26-50%,4=51-75%,5=76-100%).
Date Species of Sample
Collected bear Location No.Comments 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
5/26/82 BK (B352)upstream 9 Capture site 5 T
5/27/82 BK (B363?)upstream 12 capture site 5 T T (ants)T
5/27/82 BK (357)upstream 30 Capture site 3 2 2 T 4 (calf T (ants)T
hair?)
6/1/81 BK (B327)upstream 25 Den 5 2 T T
6/13/81 BK (B348)upstream 14 Den 5 T
5/23/81 ?upstream 5 Helms 5 T (1 fly)T
5/23/81 ?upstream 6 Helms 5 T 5 T T T T
6/1/81 ?upstream 19 Pickup 5 T (ants,
beetles)T
6/6/79 ?upstream 39 Pickup 5 T
6/8/79 ?upstream 15 Helms 5 T (flies)T
6/8/82 ?upstream 16 Helms 5 T T (flies)T
6/16/82 ?upstream 32 Pickup 5 T T T
6/19/82 ?upstream 37 Pickup 3 3 2 (ants)T
6/24/82 ?upstream 33 Pickup 5 2 hare T T
6/28/82 ?upstream 54 Helms 4 2
7/1/82 ?upstream T 5 T T
7/1/82 ?upstream 51 'Pickup T 5 T T
7/1/81 ?upstream 2 Pickup 5 T T T?T T
7/1/81 ?upstream 3 Pickup 5 T
7/1/81 ?upstream 1 Pickup 5 T
7/1/81 ?upstream 49 Pickup 3 3?T 3
7/1/81 ?upstream 47 Pickup 5 T (ants)T
5/24179 BR (G245)upstream 46 Yearling T T T 5 (squirrel)
SUMMER -FALL Upstream
8/18/80 BK (B327)upstream 36 Capture T 5 T 2
8/18/80 BK (328)upstream 38 Capture 3 4 T 2
8/19/80 BK (B303)upstream 35 Capture 3 3 T 2
SUMMER -FALL -Sloughs
8/31/82 ?downstream 13 A 5 T
8/31/82 ?downstream 42 8B 2 3 3 T T
8/30/82 ?downstream 23 8A-8B T 5 T
8/30/82 ?downstream 8 8B T 5 T
8/31/82 ?downstream 31 A 2 T 4 3
8/31/82 ?downstream 20 21 3 3 T 2 T
9/2/82 ?downstream 41 8B 5 2
1.Equisetum spp.(horesetail)5.Qplopanax horridus (Devils club)Animal matter Other
6.Arctostaphylos alpina (bearberrry)ll.Moose
Berries 7.Vaccinium uliginosum (blueberry)12.Hare or ground squirrel 16.
8.Lichens 13.Feathers
2.Vaccinium vitis-idea (lowbush cranberry)9.Grasses or.sedges 14.Fish
3.Viburnum edule (highbush cranberry)10.Ledum sp.(labordor tea)15.Insects
4.Empetrum DIgrUm (croWberry)
.,~
C.Slough inspection.
Between 30 August and 2 September 1982,14 salmon spawning
sloughs identified by fisheries subtask personnel were inspected
on the ground by myself and Dennis McAllister.Notes made at
that time were used to make a comparative ranking of the relative
degree of bear use at the sloughs inspected (Table 12).Bear use
was identified by scats,bear tracks,and salmon that had been
killed and eaten by bears.Trails were conspicuous along most of
these sloughs and it was apparent that these trails were used by
bears as well as by fisheries and hydrology personnel studying
these sloughs as part of Susi tna Studies.Some of the sloughs
contained few salmon and others contained many,in general it
appeared that use by bears was correlated with the prevalence of
salmon (Table 12).
Information on the prevalence of salmon in these sloughs and
tributaries collected by Fisheries subtask personnel is presented
in Table 13 along with an independent ranking of bear use in 1982
made from memory by Tom Crowe (ADF&G Fisheries subtask,personal
communication).Mr.Crowe walked all of these areas periodically
during summer 1982 noting ratios of tagged and untagged salmon
present.Although the data collected during these counts is dif-
ficul t to reconstruct into a ranking of sloughs by relative
salmon abundance,it appears that sloughs with highest rankings
for bear use also had lots of salmon (Table 13).It is also
apparent that salmon abundance in any slough varies markedly from
year to year (Table 13).
45
Table 12.Subjective evaluation of bear use of salmon spawning sloughs between Devils Canyon and Curry,
30 August - 2 September 1982.Ranked 1 (lowest)-10 (highestl.
no salmon
no salmon
lots of salmon,lots of human activity
difficult to fish in fast water near mouth of Indian River
B367
G379?
G379
B376,B377
B375,B376,B378
B375
B375
apparent use by
radio-collared individuals
lots of salmon
lots of brown bear sign,many fish eaten
many salmon killed by bear.
few salmon (by report from Su-Hydro fisheries staffl
few salmon
many salmon killed by bears.
few salmon
few salmon
few salmon present
CommentsSloughNo.*Index of
bear use
8A 8
8B 8
8C 4
80 6
A &Al 3
9 7
9A 3
9B 3
1.1 6
16 3
l6B 3
21 10
19 3
20 -3
Indian R 5
,.,..
.-
*Designations correspond with Su-Hydro Fisheries studies,see their reports for maps of locations •
.-
.-
Table 13.Subjective evaluation of 1982 bear use of salmon spawning areas between Talkeetna and
Devils Canyon and results of salmon counts in these areas in 1981 and 1982 (based on
infomation provided by ADF&G personnel conducting Adult Anadromous Investigations for
the Su-Hydro Fisheries project).
'i'~,
1982 No.Adult Salmon Enumerated**
AREA RIVER MILE INDEX OF BEAR USE*1981 IN***l 1982 {N***l
Slough 21 141.0 10 747 (5)2424 (9)
Slough 11 135.3 10 5483 (9)4806 (11)
Slough SA 125.1 10 1283 (5)1804 (10)
",.,
Slough 20 140.0 9 27 (2)220 (7)
Slough 9A 133.3 9 484 (6)146 (3)
Moose Slough 123.5 8 555 (5)115 (7)
Slough 8B 122.2 8 1 (l)190 (6)
Slough 8C 121.9 8 0 105 (3)
Slough 17 138.9 7 169 (7)29 (4)
~'Slough 15 137.2 7 1 (1)178 (3)
Slough B 126.3 7 NA 225 (6)
Slough 9 128.3 6 380 (5)911 (6)
~,
Slough 6A 112.3 NA 27 (3)101 (4)
Sloughs A &A'124.7 NA 437 (l0)(0)
~
Slough 8 113.7 NA 858 (5)(0)
Slough 9B 129.2 NA 678 (7)(0)
Slough 19 139.7 NA 84 (6)(0)
Indian River****138.6 10 232 (7)6703 (12)
Lane Ck 113.6 9 569 (7)2508 (11)
4th of July Ck.131.0 9 247 (6)2832 (11)
Little Portage 117.7 8 NA 407 (9)
Ck.
[,ower McKensie 116.2 8 97 (6)492 (6)
Ck.
5th of July Ck.123.7 7 2 (l)224 (4)
Skull Ck.124.7 6 24 (3)36 (4)
F Portage Ck.148.9 5 22 (l)2238 (7)
Gash Ck.111.6 5 258 (2)163 (3)
Slash Ck.111.2 5 NA 6 (1)
Whiskers Ck.101.4 5 212 (7)626 (5)
r,;jIIlllj)·Jack Long Ck.144.5 4 1 (1)54 (7)
(continued on next pagel
",-
..-
tf~Table 13 (cont'd)
1982 No.Adult Salmon Enumerated**
AREA RIVER MILE INDEX OF BEAR USE*1981 (N***)1982 (N)
Deadhorse Ck 120.9 4 a NA
Upper McKensie 116.7 4 0 24 (2)
Ck.
Chase Ck.106.9,NA 328 (8)332 (8)
Gold Ck.136.7 NA 0 37 (3)
Sherman Ck.130.8 NA 32 (4)40 (4)
*Based on recollection of Tom Crowe (ADF&G,Su-Hydro AA program)for 1982,1 =low,10 =high
bear use.
,~**These data sum all live and dead fish (Chinook,Sockeye,Pink,Chum,and Coho salmon)recorded
by Su-Hydro AA personnel (.ADF&G)during stream surveys.Different areas were surveyed from 1
to 11 times during the year which contributes to variation observed between areas and between
years in this data,survey conditions also varied.Note that the same fish would likely be
recorded numerous times in replicate surveys.
***N is the number of surveys conducted where salmon were enumerated,surveys where no salmon were
seen are not counted.--'
****The portion of the Indian River evaluated by Fisheries personnel varied in 1981 and 1982.
Most fish were found in 1982 in a tributary about ~mile up from the mouth (Crowe,pers.commun.),
during our investigation of tne Indian River we did not observe this location which explains why
we gave this area a relatively lower ranking (Table 12).
ri'('~
.~
I'~
4.Home Range Analyses--Oownstream Black Bears
Home ranges in 1982 of 2 male and 8 female black bears (including
only points through 8 September 1982)in the downstream study
area are given in Table 14.Although sample sizes are too small
to be conclusive it appears likely that males may have substan-
tially larger home ranges than females (Table 14).Relative to
upstream female black bears (Table 16)the sample -of.8 radio-
marked downstream females had smaller (mean=19 km 2 )and less
variable (50=15 km 2 )than the 13 upstream radio-marked females in
1982 (mean=79 km 2
I 50=124 km 2 ).Although these data are inade-
quate in number to be significant l they are consistent with a
hypothesis that downstream black bears that have access to salmon
resources in late summer need a smaller home range than upstream
black bears that must range further in search of later summer
food resources like berries that are patchy in distribution or
abundance.These data would also be consistent with a hypothesis
that summer foods other than salmon (like berries)that bears may
depend upon are less patchYI more abundantI or in closer proxim-
ity to spring foods in the downstream study area relative to the
upstream area.In illustration of the last point l it may be that
downstream bears use devils club berries in late summer and
devils club may be found primarily in riparian areas that coin-
cide with the area used by bears in early spring;upstream bears l
in.contrast l may use blueberries in late summer (devils club is
uncommon in the upstream study area)and must range further from
49
.....
.-
spring foraging areas t~find acc~ptable concentrations of blue-
berries.Smaller home ranges in the downstream area,for what-
ever reason,may mean that the population can maintain a higher
black bear densi ty than upstream populations.
Distribution maps for radio-collared black bears are provided in
Appendix I.One noteworthy observation in the movements of bears
in the downstream area is the apparent dispersal of a 5 year old
male (B365,Figure 13)from the Susitna drainage to the Chulitna
drainage (thi s bear denned on the bank of the Chulitna in
1982/83).This apparent dispersal may account for the large
-!
indicated home range of this bear (655 km 2 ,Table 14).
50
Table 14.Home range sizes for the Su Hydro downstream black bears
1982
Observation Period Home Range
Downstream (No.of Locations)(km Z )Comments
--MALES
365 (5)May-Sep (8)655
366 (6)May-Aug (10)136 Hunter kill 9/82
FEMALES
369 (3)May-Sep (14)10
367 (4)May-Sep (13)17
.l!1.W"\375 (5)Jun-Sep (13)17
377 (5)Jun-Sep (12)8
376 (6)Jun-Sep (8)19
378 (6)Jun-Sep (11)8
370 (7)May-Sep (14)15
372 (9)May-Sep --illl.54
•x(all females)=~12.4)19
S.D.=15
range =(8-14)(8-54)
x(all males and females)=(11.7)94
S.D.=201
I~range =(8-14)(8-655)
B.UPSTREAM STUDY--BLACK BEARS
1.Sex and Age Composi tion of Study Animals.
....In spring 1982 intensive efforts were made on 26-27 May to
increase the sample of radio-collared black bears.Most effort
.-
was directed at the Watana impoundment area where impacts on
black bears are expected to be most marked (Miller and McAllister
1982).
Two radio-collared bears were recaptured in dens on 1 April 1982,·
.-
one of these was a subadult and the other was a female with 2
yearlings.Dens of other black bears with yearlings could not be
entered at this 'time because of difficult snow conditions .
.-Eleven new black bears were captured and marked (8 new transmit-
ters).In addition,one previously captured bear that had shed
its collar in its 1890/81 den'was recaptured and .recollared.
This male (B322)died in mid summer 1982 of unknown causes.It
is interesting that this male weighed 154 pounds when first cap-
-tured on 19 August 1980 (at age 4.8)but its weight was estimated
at only 90 pounds in spring 1982 i this lends credence to our-speculation (Miller and McAllister 1982)that 1981 was a bad
berry year for bears and that spring condition is affected by the
previous year's berry crop.
-52
Table 15.Number of point-locations of radio-collared black bears for upstream Su-Hydro studies:
f'lil':'"
1980,1981,and 1982.
Year of
initial No.of point-No.River
Bear capture locations Crossings-ID (age)1980 1981 1982 1980 1981 1982 Comments
MALES
330 1981 (1)w/318 14 0 Inactive,died summer 1981
323 1980 (2)6 18 19 2 4 2 Active
358 1982 (2)17 0 Active
319 1980 (3)6 9 4 3 Inactive,died summer 1981
291 1980 (4)7 0 Inactive,died summer 1980
322 1980 (4)5 7 0 1 Collar shed in den,recap-
tured 1982,died June '82
320 1980 (4)2 1 Shot by hunter fall '80
357 1982 (4)18 4 Active
359 1982 (4)18 0 Active
324 1980 (5)6 19 20 0 4 4 Active
342b 1981 (5)40 0 Shot by hunter,fall '81
343 1981 (5)16 18 3 3 Active
300 1980 (7)3 Died summer 1980
3.60 1982 (7)20 2 Active
302 1980 (8)7 36 10 0 12 2 Collar shed in 1980,but
recaptured in 81,
radio failure 1982
303 1980 (8)15 18 18 2 0 0 Active
305 1980 (9)9 2 Shot by hunter fall,'80
346 1981 (9)16 20 2 4 Active
348 1981 (9)7 8 2 1 Killed by hunter 9/82
287 1980 (10)17 15 16 0 2 2 Killed by hunter 9/82
30l!1980 (10)15 19 3 0 0 1 Shed collar 5/82
All Males 98 227 212 11 32 20
FEMALES
t""'"329 1981 (1)w/327 19 18.2 2 Active
349 1981 (4)6 19 0 0 Active
363 1982 (4)18 0 Active
318 (wile 1980)1980 (5)6 20 18 0 0 0 Active
r-326 (w/2c 1980)1980 (5)3 0 Shot by hunter,fall 1980
327 (w/2c 1980)1980 (5)6 34 18 1 8 7 Active
354 (w/2@c,1982)1982 (5)19 0 Active
328 (w/2c 1981)1980 (6)6 18 0 0 Collar shed in 81/82 den
364 1982 (6)16 7 Missing
~301 (w/2c 1981)1980 (7)20 14 16 2 0 O·Missing
317 (w/2c 1980)1980 (7)6 18 17 0 0 0 Active
361 1982 (7)18 2 Active
290 1980 (8)18 i4 4 0 Inactive,collar not
replaced,neck infected
289 (w/3c 1981)1980 (9)14 19 19 4 0 0 Active
288 1980 (10)16 0 Collar shed
321 (w/2c 1981)1980 (10)6 14 18 0 2 0 Active
325 1980 (11")6 8 0 2 Active,collar shed in den-but subsequently recaptured
316 (w1c 1980)1980 (12)4 0 Shot by hunter,fall 1980
All Females 111 I84 214 11 --14.--9--
TOTAL BOTH SEXES 209 411 416 22 46 29
Observations of unmarked bears 49 54 NA
TOTAL 258 465 416 22 46 29
•
The mean age of 7 males captured in upstream studies during
spring 1982 was 4.2 (2-7)and for 5 females it was 5.4 (2-9).
The 1982 sex ratio of captured bears in the upstream study (6
males:5 females)WSiS markedly different from that of captured
bears in the downstream study (3 males:lO females).Capture data
of all black bears handled to date are given in Table 9.Two
radio-collared black bears were shot by hunters in 1982 (B287 and
B348)Bear (B304)shed its radio-collar.Bear (B302)had a known
radio failure.And two bears (B364 and B301)are missing.Nine-
teen black bears currently have active radio-collars in the
upstream study area.
Number of point locations and river crossings by radio-collared
upstream black bears are given in Table 15 .
2.Black Bear Census
An effort was made on 18-22 August 1982 to census black bear pop-
ulations in the area of the proposed impoundments.The technique
_utilized was the Lincoln Index using the ratio of radio-marked to
unmarked black bears observed during intensive survey flights
(approx.5 minjmi 2_)using approximately ~mile transects.Indi-
vidual sample units (n=31)averaging 14 mi 2 (8-22)were identi-
fied on a map using obvious geographic features as boundaries.
The total area censused was approximately 445 mi 2 and included
most of the known black bear habitat in the upstream study area
based on the preceding 2 years of radio-tracking data.Areas
54
-
55
The timing of the census was chosen to correspond with the period
when previous experience indicated that black bears would be vis-
ible in the shrubland habitats adjoining forested areas.This
shrubland habitat is relatively rich in blueberries at this time
of the year.A replicate of this design that will yield a second
estimate is planned for spring 1983 when bears have emerged from
dens but prior to leaf emergence which would restrict·observ-
ability.
-.The study area can be characterized as a finger of acceptable
black bear habitat along the Susitna River surrounded by higher-elevationl unforested habitats where our radio-marked black bea,rs
seldom ve~ture.These conditions describe an essentially closed
black bear population not open to immigration or emigration
except at the downstream end of the census area.The census
results l correspondinglYI describe a relatively discrete popula-
tion.The density of this population would depend on the area
u"tilized in calculating density I in general the area occupied by
this black bear·population is the smallest in the spring and
largest in the late summer at the time the census was conducted.
The formula used in making the'population estimate was (Ricker
1975):N=(00+1)(C+1)j(R+1).In this formula oo=number of radio-
marked bears in the census.area (21 black bears)I R=number of
radio-marked bears observed in the census (9)I and C=number of
black bears observed during the census (38 excluding cubs).Con-
fidence intervals were based on the Poison distribution (Ricker
1975).Because cubs were excluded the population estimate
56
·""'"
reflects the population older than 1.0 years of age.No radio-
collared yearlings were present in the census area although
unmarked yearlings ·may have been observed;yearling black bears
cannot accurately be identified as yearlings from the air.
Many assumptions must be·made in the use of this estimation pro-
cedure and numerous sources of bias are possible (see Seber
1973).The most probable source of bias is incomplete mixing of
marked and unmarked individuals.Of the 21 marked bears present
in the area,8 were originally captured in August tagging efforts
(2 of these were seen during the census)and the remaining 13
were captured in spring tagging efforts (7 of these were seen
during the census).It is possible that these 2 groups had dif-
ferent probabilities of being observed during the August census.
-Also,because recent years'capture efforts have concentrated on
the vicinity of the Watana impoundment (where impacts are
expected to be more marked),a higher proportion of bears in this
area may have been marked relative to more downstream areas.
Individuals vulnerable to capture may have had higher probabil-
r-i ties of being seen in the census;if so this would yield an
underestimate of population size.
The low numbers of bears seen was surprising.As mentioned in.....
,
the Phase I report (Miller and McAllister 1982:93)at the same
_time of the year in 1980,pilot Al Lee saw 35 black bears by
himself in a small portion of the census area during l~days of-spotting effort.No bears were seen in this area during the 1982
census.
-57
Mr.Lee was convinced during the census that "something had hap-
pened"to the black bears in this region,I had the same impres-
sion.Whether anything actually happened,however,cannot be
shown at this time based on available information.During the
apparent bad berry year of 1981 several radio-marked black bears
moved downstream out of the study area as mentioned in the Phase
I report (p.105),these 3 bears (all males)represented 15%of
the 20 black bears marked at that time.One of these bears-
remained outside during most of 1982 and the other two returned.
Only 1 radio-collared bear (B322)died insprinq 1982,two died
in summer 1981 (B319 and B330 the latter a yearling).It-is pos-
sible these deaths were related to poor nutrition resulting from
the berry failure in 1981,but other causes may have been respon-
sible (B319 died in late July 1981,and B330 in mid-August 1981).
,,,...These observations on radio-collared bears are difficult to rec-
oncile with a hypothesis that the bad 1981 berry crop resulted in
a major reduction in upstream bear populations in 1982.A hy-
pothesis that disturbance from the helicopter traffic associated
with project-related studies resulted in the apparent decline is
-similarly difficult to reconcile with these observations of
radio-marked bears.
Straightforward application of the census results provided a 1982
population estimate in the census area of 86 blackobears 1 year
~old or older with a 95%confidence interval of 47-172.Given the
above discussion this estimate should clearly be considered pre-
liminary.The planned spring 1983 census will provide an inde-
-
58
-
-
-
.....
-
pendent estimate.Even if correct,this estimate reflects the
bear population in 1982.As mentioned above it is possible that
the 1982 population was significantly lower than was present when
the study was init~ated in 1980 and is lower than is typical in
the area.My guess on the number of bears in the impoundment
study area based on observations in 1980 was 150-200.Acceptance
of this guess over the calculated estimate requires either ident-
ification of a major source of bias in the census that is not
evident at this time or acceptance of the conclusion that a major
population reduction occurred through selective losses or emigra-
tions that was more predominant in the unmarked segment of the
population than i~the radio-marked segment.It is feasible that
emigrations of younger individuals (only 1 yearling and no 2-year
olds were marked in 1981)during years of berry scarcity would be
more common than emigrations of better established older individ-
uals.
Although there is no direct evidence for such a selective emigra-
tion of subadult bears it is possible to estimate the magnitude
of such a potential source of loss.The census result can also
be corrected f(Jr cubs by similar guesses added to the census
estimate.Cubs,yearlings and "2-year old bears might comprise
about 40%of a black bear population.Adding 40%to the census
estimate of 90 bears provides an estimate of 126 bears,similar
corrections to the confidence interval extends this to 65-241.
59
-
3.Home Range Analyses--Upstream Black Bears
Home range data for radio-collared black bears in the upstream
f,~
study area for eac~year of the study is given in Table 16.As
mentioned by Miller and McAllister (1982),the method currently
used to calculate home ranges is imprecise and may include sub-
stantial areas not occupied by the bear,especially for bears
that make extensive seasonal movements.It should also be noted
~
that home ranges given in Table 16 for 1982 include only points
collected prior to 9 September 1982,the data for preceding years
include all points.Correspondingly,the 1982 data presented in
Table 16 will change (increase)in some cases when additional
1982 points are included in the home range calculatiohs.-
Keeping these limitations in mind,the 1982 home ranges averaged
smaller than the 1981 home ranges for females (79 km 2 vs.200 km 2 ,
wi th corresponding standard deviations of 124 km 2 and 355 km 2 ,
Table 16)and for males (163 km 2 vs 230 km 2 with SDs of 254 km 2
and 185 km 2 ,respectively).These differences are not statis-
tically significant because of the large variation in individual
home range size (6-905 km 2 in 1982,Table 16).Regardless,the
differences between 1981 and 19B2 are in the direction that would
be expected if our hypothesis that the apparent poor 1981 berry
crop resulted in larger 1981 home ranges than in 1980 (Miller and
McAllister 1982).More insights into this possible pattern can
be gained through analyses of annual home ranges of the same
individual as'was done for brown bear earlier in this report.
60
1 I 1 l )l 1 )j J J j i 1 J I 9 j
Table 16.Home range sizes for Su-Hydro upstream study area black bears.(Includes individuals with 5 or more relocations).
1980 1981 1982
Bear ID Observation Period Home Range Observation Period Home Range ObservatiQn PerIod Home Range.
(age @ capture)(No.of locations)(km 2 )(No.of locations)(km 2 )(No.of locations)(km 2 )Comments
Males
I
330 (1)--------May-Oct (14)10 --------Died 7/81
323 (2)Aug-Oct (6)20 May-Oct (18)383 May-Sep (15)905
358 (2)----------------May-Sep (14)6
319 (3)May-July (6)67 May-July (9)43 --------Died 7/81
291 (4)May-July (7)20*----------------Died 7/80
322 (4)Aug-Oct (5)10 --------May-Jul (7)21 Collar shed in den 80/81,
recaptured 5/82,died 7/82
357 (4)----------------May-Sep (14)10
324 (5)Aug-Oct (6)29 May-Oct (19)248 May-Sep (17)140
3428 (5)--------May-Sep (40)611 --------Shot by hunter 9/81
343 (5)--------May-Oct (16)289 May-Sep (14)331
359 (5)----------------May-Sep (14)73
302 (8)May-July (7)4 May-Oct (36)326 May-Jul (10)51 Collar shed in 181,recap-
tured in 182,missing 182
303 (8)May-Oct (15)95*May-Oct (18)92 May-Sep (15)74
305 (9)May-Aug (9)48*----------------Killed by hunter,180
346 (9)-----'May-Oct (16)62 May-Aug (15)87
348 (9)--------Aug-Oct (7)388 May-Jun (7)17 Killed by hunter,9/82
287 (10)May-Oct (17)136*May-Oct (15)268 May-Sept (16)239 *,**Killed by hunter,9/82
304 (10)May-Sep .J..ill 34***May-Oct --ill.!.37***--------Collar shed 7/82-'-'--
x(all males)=(9.2)46 (18.9)230 (13.2)163
S.D.= .--42 --185·--254
range =(5-17)4-136 (7-40)10-611 (7-17)6-905
(continued on next pagel
I 1 -I }}1 ,)J J I 1 J J j j
Table 16.(continued)
1980 1981 1982
Bear ID Observation Period Home Range Observation Period Home Range Observation Period Home Range
(age @ capture)(No.of locations)(km 2 )(No.of locations)(km 2 )(No.of locations)(km 2 )Comments
FEMALES
329 (1)--------May-Oct (19)15 May-Sep (15)9 weaned in June 1981
363 (3)----------------May-Sep (14)18
349 (4)--------Aug-Oct (6)36 May-Sep (16)16
318 (5)Aug-Oct (6)25 (w/1c)May-Oct (20)1036 May-Sep (14)471 weaned 1@1 in '81
327 (5)Aug-Oct (6)3 (w/2c)May-Oct (34)31 May-Sep (14)34 weaned 2@1 in '81
354 (5)----------------May-Sep (15)63 W/2@C
328 (6)Aug-Oct (6)4 May-Oct (18)28 (w/2c)--------collar shed in 81/82 dens
301 (7)May-Oct (20)18'"May-Oct (14)12 (w/2c)May-Sep (16)18 weaned 1@1 in '80,
missing since 9/28
317 (7)Aug-Oct (6)4 bil2c)May-Oct (18)14 May-Sep (14)44 weaned 2@1 in '81
360 (7)----------------May-Sep (14)124
361 (7)----------------May-Sep (14)69
290 (8)May-Oct (18)45'"May-Aug (14)116 --------weaned 2@1 in '81 not reco1-
1ared in '81 as neck was
infected
I
289 (9)May-Oct (14)43'"May-Oct (19)26 (w/3c)May-Sep (15)26 weaned 2@1 in '80,
had cubs in 1981
364 (9)----------------May-Sep (15)121
288 (10)May-Aug (16)7 -------- --------collar shed in '80
321 (10)Aug-Oct (6)3 May-Oct (14)771 (w/2c)May-Sep (16)13 lost cubs in August '81
and made big movement
325 (11)Aug-Oct (6)8 Aug-Oct ~117 Collar shed in 80/81 den----recaptured in 8181
x(A11 Females)=(10.4)16 (16.7)200 (14.8)79
S.D.=16 ---355 --124
_Range=(6-20)3-45 6-34 12-1036 (14-16) (9-471)
x(A11 Males &Females)=(9.8)31 (17.9)215 (14.0 119
5.0.=---35 ---273 --198
Range=(5-20)3-136 (6-40)10-1036 (7-17)6-905
*Included in statistical comparisons
*'"Excludes atypical location of 80/81 den,with den home range for 1980 &1981 was 104 km 2•
,..,.
Horne rct:nges for 16 individual black bears were calculated in both
1981 and 1982,8 males and 8 females (Table 16).Five males
(324,302,303,348,287)had smaller home ranges in 1982 than
in 1981 (mean decrease=51%,range=1-84%),3 males (323,343,and
346)had larger home ranges in 1982 than in 1981 (mean increase=-
64%,range=15-136%).Four females (329,349,318,321)had
smaller horne ranges in 1982·than in 1981 (mean decrease=62%,
range=40-98%),.3 females (327,301,317)had larger.home ranges
in 1982 than in 1981 (mean increase =91%,range =10-214%).One
female that had cubs in 1981 had the same size home range in 1982
(B289).For B301 (inclu~ed -above)the 1982 home range was larger
than the 1981 home range by 50%,probably because she had cubs in
1981.These data tend in the right direction but do not provide
clear support for our hypothesis that black bear movements were
more extensive than normal in 1981 because of the apparent poor
1981 berry crop.Excluding females with cubs in either 1981 or
1982,9 bears had smaller horne ranges in 1982 than in 1981 and 5
had larger home ranges.
For male B323 the steady increase in home range in 1980 (20 krn 2 ,
Aug.-Oct.),1981 (383 krn 2 ,May-Oct.),-and 1982 (905 krn 2 ,May-8
Sept.)may reflect dispersal rather than food availability (this
bear was 2 years old in 1980).In 1982,this bear apparently
moved from the High Lake vicinity to the Vee Canyon vicinity and
has denned near Vee Canyon,this may account for the 136%in-
crease in 1982 home range size over the 1981 home range.The
63
'1""
I
!
largest percentage increase in home range (214%for B3l7)repre-
sented a change from 14km 2 in 1981 to 44 km 2 in 1982,no reason
for this large percentage increase for this individual.is readily
apparent and it may be a artifact of small numbers or method of
calculating home range.
4.Berry Abundance
In the Phase I report (Miller and McAllister,1982)it was noted
that black bears in August 1981 made extensive movement in both
upstream and downstream di rections .These movements were much
less extensive in 1980,when berry crops were thought to have
been normal,than in 1981 when berry crops were thought to have
been exceptionally bad.Our hypothesis was that black bears made
~more .extensive movements during poor berry years in search of
better foraging areas.Downstream movements may have been moti-
vated by salmon runs downstream of Devils Canyon and upstream
movements by higher relative berry abundance.
This hypothesis was tested in August 1982,a year during which
berry production in the Watana Creek-Tsusena Ck.area was thought
to be slightly below average.During thi s period in .1982,6 of
16 radio-marked black bears made extensive movements from their
spring-early summer ranges to upstream areas as happened in 1981.
Others made more moderate upstream movements at this time (see
Section IX-B-3).A vegetative transect was run in-woodland black
spruce habitats in the Deadman Ck.vicinity and another in the
same habi tat in an upstream location (Vee Canyon-Oshetna River).
64
Additional transects were run in birch shrub habitats in each of
these 2 locations.Each transect was compri sed of ten plots
(each 1 square meter)oriented so 5 plots were arranged at 10 m
I~""
spacings downslope and the remaining 5 at the same spacing
parallel to the slope.All berries in each plot were picked and
counted and canopy coverage of plants in each plot was estimated.
~
The results are given in Table 17.Dot Helms (Plant Ecology sub-
task)assisted in this work which was conducted on 21 August
1982.
r
Contrasting the 2 downstream
(except crowberries)were more
habitats suggests that berries
abundant in the birch shrub than
65
Table 17.Berry abundance in 4 transects (10 plots of one square meter/transect)in the~impoundment study area.
Transect 1 Transect 4 Transect 2 Transect 3
Location
Elevation
Aspect
Slope
Vegetation type
Between Vee Canyon
and Oshetna (upstream)
2325 feet
218 0
8 0
WSB
Confluence of
Susitna R.and Deadman
2100 feet
239 0
40
WSB
Vee Canyon-
Oshetna (upstream)
Ck.(downstream)
3050 feet
216 0
50
B*
Middle Deadman-
Watana Camp
(downstream)
2450 feet
201 0
7°
B
*Transect #2 was clearly in a birch shrub type a1th~ugh according to the vegetation map it was
woodland black spruce (WSB).
Bearberry (Arctostaphylos uva-ursi)
No.of berries 22
range 0-20
77
0-31
1l.7
57.0
15-80
23.0
23
0-15
8.7
0-30
8.6
1
0.4
0.2
0
in
o
200
0-50
19.7
10.9
0-50
14.5
45
0-16
489
0-164
54.9
36.0
5-80
24.6
6.7
2-10
3.0
o
o
112
0-58
17.9
10.2
0-30
10.2
32
0-8
3.2
3.9
0-15
5.1
31
15-70
17.9
2.9
0-10
3.4
21.2
5-60
15.9
3.4
0-10
3.5
(y.vitis-idaea)
28
0-15
5.1
Blueberries (Vaccinium uliginosum)
No.berries 303
range (no/plot)1-191
S.D.57
%canopy cover:
.mean
range
S.D.
Crowberries (Empetrum nigrum)
No.berries 17
range/plot 0-10
S.D.3.1
%Canopy cover:
mean
range
S.D.
Lowbush cranberry
No.berries
range
S.D.
%canopy cover:
mean
range
S.D.
-
-
in the woodland spruce;this supports the hypothesis of-why black
bears move out of the spruce habitats into the adj oining shrub-
lands in late August..The same pattern held in comparisons of
the 2 upstream habitats except that crowberries were also more
abundant in the upstream birch area relative to the adjoining
spruce habitat.Canopy coverage of berry plants in both years
also suggests the presence of more bushes in the birch shrub type
relati ve to the spruce type.
It is noteworthy that the apparent patchy distribution of berries
makes it necessary to contrast berry abundance between different
areas in the same habitat type in order to accurately interpret
bear movements.Motives for these movements would remain obscure
if berry abundance is just characterized by habitat type through-
out the study area.These results suggest needed modification in
the design of Plant Ecology subtask studies.Insufficient num-
bers of berry transects were run in 1982 to provide conclusive
evidence of relative berry abundance in these habitats,the data
collected,howeve-r,are consistent with our earlier hypothesis.
5.Population Biology and Productivi ty--Black Bears
None of the previously radio-collared black bear females had a
litter of newborn cubs in 1982 although 4 (317,318,327,321)
potentially could have (Table 18).It is possible that the fail-
ure of these bears to produce cubs in 1982 was related to the
apparent poor 1981 berry crop (Miller and McAllister 1982),simi-
lar relationships have been observed in Minnesota (Rogers 1976).
67
Possibly because of their failure to have cubs in 1982,19 of 20
radio-collared females (B354 is the exception)could potentially
have cubs in 1983 (Table 18).For 9 of these bears (ID numbers
from 361-377,Table 18)the reproductive status was not known in
1981 as they were not captured until spring 1982,correspond-
ingly,the high proportion expected to produce cubs in 1983 may
be exaggerated by a capture bias against females with newborn
cubs that may exist.These data are consistent with our hypothe-
sis that a direct relationship exists between food supply and
black bear producti vi ty.
As discussed earlier in the brown bear section,this hypothesis
is important to determination of the impact of the project on the
bear population.The project is expected to adversely impact a
large proportion of avai 1ab1e black bear habitat in the study
area,especially in the vicinity of the Watana Impoundment
(Miller and McAllister 1982).Much of this impact will likely be
expressed through decreased productivity of the black bear popu-
.'1~
1ation if a direct relationship between productivity and avail-
able food supply exists as hypothesized.
6.Food Habi ts of Upstream Bears
Results of analyses of 23 bear scats collected in the upstream
study area during spring and 3 collected in late summer are pre-
sented in Table 11.The small sample of scats is inadequate to
illustrate bear food habits but provides some general indications
of what to expect from more intensive work scheduled for 1983.
68
Table 18.Predicted spring 1983 reproductive status of radio-collared female black bears.
ID 1983 age
289 12
301 (missing)10
317 10
318 8
327 7
321 13
349 6
361 8
expected 1983 Status
cubs
cubs
cubs
cubs
cubs
cubs
cubs
cubs
Comments
weaned ylgs and bred in '82
weaned ylgs and bred in '82
weaned ylgs in 181,no cubs in 182
weaned ylgs in '81,no cubs in '82
bred in '82
weaned ylgs in '81,no cubs in '82
lost cubs in '81,no cubs in '82
no offspring in '81,or fall '81
no offspring in '82
F"
'I
I
363
364 (missing)
354
329
367*
369*
378*
376*
374*
372*
375*
370*
377
5
7
6
3
5
4
4
5
7
10
6
8
6
cubs
cubs
yearlings
barren
cubs
cubs?
cubs?
cubs?
cubs
cubs
cubs
cubs
cubs
no offspring in '82,bred
no offspring in '82,bred
cubs in '82
subadult,not bred in '82
first litter?
first litter
first litter
first litter,thought might have
had ylgs in spring '82,based on
age this is now considered unlikely
weaned yearlings in '81 (probably)
bred in '82
may have weaned yearlings in '82
*bear occurs in the downstream study area
.,~
Horsetail (Equisetum sp)occurred in 16 of the spring scats
(70%),in most cases this species comprised the bulk of the scat
(table 11).Horsetail is a mesic species and casual observations
suggest that a large proportion of the habitat where horsetail is
currently found will be inundated.This needs to be verified by
sampling efforts of the Plant Ecology Subtask.
Grasses and sedges occurred in 6 scats (25%),mostly in the late
spring (Table 112).This observation,along with the abundance
of horsetail in scats,is consistent with my speculation (Miller
and McAllister 1982)that bear movements to the impoundment area
in the early spring may be motivated by the earlier phenology of
these species in this area relative to higher elevations.Over-
wintered berries were also common in spring scats (Table 11).As
expected,berries (especially blueberries and crowberries)were
common in late summer scats (Table 1i).
7.Black Bear Den and Denning Characteristics--Upstream and
Downstream Studies.
70
study areal the band of acceptable denning locations appears to
become progressively narrower and more confined to the immediate
vicini ty of the Susi tna River;much the same pattern as ·seen for
overall black bear_distribution in the study area.This corre-
lated with the high rate of den inundation by the Watana impound-
ment (13 out of 24 dens located)and the relatively low rate for
the Devils Canyon impoundment (lout of 18 located).Data ihdi-
eating a high rate of reuse of dens in successive years (a mini-
mum of 16 out of 25 dens,2 of these tentative)and competition
for den sites (2 instances observed)suggest that acceptable
al ternative dens are scarce in the upstream study area.
To date,54 black bear den sites have been located wi thin the
study area;12 downstream of Devil Canyon,18 wi thin the Devil
~~Canyon dam impact area,and 24 within the Watana Dam impact area.
Twenty-five of these dens have been visited on the ground;2,14,
and 9,respectively,for the above·areas.
Three dens were only approximately located,26 dens in use during
the current winter (1982/83)will be visited during the summer of
1983.
The 54 black bear dens range in·elevation from 1,000 feet to
....4,340 feet,only 2 dens were above 3,100 feet.The mean eleva-
tion for the 54 dens was 2,053 feet (SD=575.8).Of the 18 denrsitesinthevicinityoftheproposedDevilsCanyonImpoundment,
71
only one will be flooded at an impoundment elevation of 1,450
feet,the mean elevation of these 18 dens is 2,108 feet (range=
1,400-4,340,50=670).Of the 24 den sites in the vicinity of the
proposed Watana impoundment,13 would be flooded at an impound-
ment elevation of 2,200 feet,the mean elevation of these dens
was 2,258 feet (range=I,675-3,60Q,50=441).Downstream of the
Devils Canyon darn site,the mean elevation of 12 black bear dens
was 1,560 feet (range=I,000-2,100,50=369).Included in these
values are tentative elevations of the 1982/83 den sites.
Characteristics of den sites ·used in the last 2 winters (1980/81
and 1981/82)are given in Table 20.Of the 25 black bear dens
examined on the ground,10 were in natural cavities and 15 were
excavated.Virtually all of the natural cavity dens appear to
have been used in preceding years,some may have been used for
decades or longer.Of the 14 dug cavities,7 were considered to
have been previously used.Radio-tracking of tagged black bears
provided positive knOWledge of reuse of 6 den sites out of 29
observed for more than one year.Additional reuse of these dens
by non-radio-collared bears has not been assessed but doubtless
is common.Interestingly,5 radioed individuals have reused the
same den for 2 or more years arid in 2 other instances an attemp-
ted reuse was evident but the den was found already occupied by
another radio-collared bear.
72
Of the 54 black bear dens known,48 occur within habitat types
that include a considerable proportion of alder or larger trees.
Only 6 den sites were found in the relatively open habitat types
of dwarf birch or tundra.
73
~~-"'Cl J j -j J
~le 19.Characteristics of black bear dens in the Susitna study area during winters of 1980/1981,1981/1982
Eleva-
Den Bear Age at tion Slope Aspect
No.ID No.Exit (feet)(Degrees)(True N)Vegetation
%Canopy ENTRANCE
Tree Ht.Width
Coverage (cm.)(cm.)
CHAMBER
Ln.Width
(em.)(em.)
Total Previously
Ht.Length Used?
(em.)(cm)(Yes/No)A B c
!\OTURAL CAVITIES
FEMALES w/offspring (at exit)
w/2 cubs 8 B321 11
W**Alder,Birch,Moss
w/2 cubs
w/l
19
32
33
B328
B328
B318
7
8
7
2825
1950
2075
1890
42
40
64
41
208
218
361
Alder
Alder
Birch
o
o
50
o
79
41
49
51
26
93
39
43
127
84
69
68
54
76
71
44
62
610
180
654
Yes
Yes
Yes
Yes
2
4
3
3
No
No
No
No
?collar
shed in den 6 B325 12 1490 30 178 Birch/alder/spruce 50 49 27 100 74 55 113 Yes 2 No
13*B304*11
18*B322*5
.48·Willow/alder/aspen
MALES
7#B287
9###B324
10#B303
11
6
8
1700
2240
1690
4340
1840
46
30
.50
24'
53
170
88
52
158
Cottonwood/willow/
birch
Alder
Rock pile/tundra
Alder/rock slide
50
o
o
o
62
38
93
44
34
36
122
137
108
89
70
82
42
45
94 869
Yes
Yes
Yes
?*
?*
2
3
1
No
No
No
No
Yes
~G DENS
FEMALES w/offspring (at exit)
w/2 cubs 2 B301 8
4#B289 Alder/willow/spruce 70
21##B327
w/3 cubs
w/2 ylgs
w/l ylg
w/2 ylgs
w/2 ylgs
11
12
50
34
43
55
58
B317
B318
B301
B321
B317
B349
B327
10
8
6
6
9
12
9
5
7
2065
2000
2050
2725
2000
2275
2125
2250
2650
1675
34
18
36
24
35
43
22
8
21
26
191
211
86
122
379
219
184
153
207
321
Alder/birch
Alder
Dwarf birch/moss/
tundra
Alder/birch
Cottonwood,Spruce
Alder
Dwarf Birch
Alder,Spruce
Birch,Alder
90
o
o
80
20
10
o
10
70
49
39
27
24
22
28
29
32
39
35
43
72
41
42
59
56
43
36
54
49
97
142
93
95
163
76
99
92
56
86
92
127
93
84
203
136
118
89
92
73
51
55
78
40
116
98
79
63
55
61
151
290
128
145
198
193
193
150
124
160
Yes
No
No
No
?
Yes
No
No
No
No
3
1
3
5
4
2
2
2
3
No
No
No
No
Yes
Yes
Yes
No
No
Yes
.J
(continued on ne~t page)
-1 ---CCC_j j )J J
rable 19.(continued)
Eleva-%Canopy ENTRANCE CHAMBER Total Previously
Den Bear Age at tion Slope Aspect Tree Ht.Width Ln.Width Ht.Length Used?
No.ID No.Exit (feet)(Degrees)(True N)Vegetation Coverage (cm.)(cm.)(em.)(cm.)(cm.)(cm)(Yes/No)A B C
MALES
20*B323*3 1950 46 176 Alder/birch - ---- --?*--Yes
35 B304 12 1650 36 79 Birch 25 53 147 100 173 -660 Yes 2 No
38 8343 6 1200 39 313 Birch,Alder,Spruce 60 35 62 --- -
No ?
39 B348 10 1375 43 240 Birch,Spruce 20 57 91 116 172 183 530 Yes 1
57 B302 10 2025 41 236 Spruce,Birch 40 55 63 94 138 '101 188 Yes 2 -Yes
i
~OCI~~m_
KNOWN CAVITY T:PE
--2340 35 (254)Dwarf birch 0 50 54 - --170 No --No
40 B324 7.140P**-------------?
49 B323 4 1875**41 204**Spruce,Birch ------- ---?
51 B346 10 2500**-188**----- ---- ---No
UNKNOWN SEX
61 ??2400 35**163**Spruce,Alder,Birch 80 ------No 4 -No
*Actual den site not found or too difficult to enter.#Used by the same bear two consecutive winters
**Approximate value ##Used by the offspring during natal winter and subsequent winter
A SUbjective characterization of quality,1 =highest and 5 =lowest.-###Used by different radio-collared bear during subsequent winter
B Will be flooded by Devil1s Canyon?
C Will be flooded by Watana Impoundment?
Miller,Sterling D.
Hydroelectric
Studies,Vol.
x.References
Egbert,A.,J.and A.W.Stokes.1974.The social behavior of
brown bears OIl an Alaskan salmon stream.Pages 41-56 In
"...,Bears -Their Biology and Management (Pel ton,Lentfer and
Folk,eds).IUCN New Series #40.
Frame,George W.1967.Black Be.ar Behavior and Predation on
~
Salmon at Olsen Creek,Alaska,1967.Unpublished manu-
script,Univ.of Alaska,College.48 pages.
Glenn,L.P.,J.W.Lentfer,J.B.Faro,and L1 H.Miller.1974.
Reproductive biology of female brown bears,iJrsus arctos,
McNeil River,Alaska.Pages 381-390 In Bears Their
.....Biology and Management (Pel ton,Lentfer and.Folk,eds).
IUCN New Series #40.
and Dennis C.McAllister.1982.Susitna
Project,Phase I Final Report,Big Game
VI,Black and Brown Bear.Alaska Dept.of
Fish and Game.233 pages.
r
Rogers,Lynn.1976.Effects of mast and berry crop failures on
survival,growth and reproductive success of black bears.
41st N.Am.Wildl.Conf.Trans.,431-438.
76
XI.Appendices
Appendix I.Home ranges of Individual radio-collared black.bears
~,
and brown bears in the downstream study area.Points occurring
between August 1 and September 9 are indicated with a hexagon.
Only data through Septerilber 9,1982 have been compiled and are
I!'l~
illustrated.
•
77
r
--.•,-:1:
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ell
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at-
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r
Appendix 2 -Den entrance and emergence data,brown bears and black bears
89
-···1 ····1 1 1 1 j ]
•
Table A.Den entrance and emergence dates of radio-collared brown bears for the winter of 19Bo-81 ("5"is the standard deviation,but it
includes variability from the fluctuating time between observations,as well as variability in denning times).
19Bo Entrance 1981 Emergence Days In Den
Bear ID Sex Min.Max.Mid.Min.Max.Mid.Min.Max.Mid.
280 M 13 Det.27 Oct.20 Oct.7 Apr.21 Apr.14 Apr.162 190 176
2Bl F 13 Oct.27 Oct.20 Det.7 Apr.21 Apr.14 Apr.162 190 176
283 F 9 Det.27 Det.18 Det.30 Apr.5 May 2 May 185 208 197
294 M 27 Oct.21 Apr.3D Apr.26 Apr.176
299 F 13 OC~.27 Det.20 OCt.7 Apr.21 Apr.14 Apr.162 190 176
30B F 13 Det.27 oct.20 Det.3D Apr.5 May 2 May 185 204 195
312 F 29 Sept.3D Apr.6 May 3 May
313 F 9 Sept.9 Oct.24 Sept.21 Apr.24 Apr.22 Apr.194 207 200
277 F 27 Det.
MEAN 6 Det.25 Oct.15 Det.19 Apr.28 Apr.23 Apr.----rrs -r98 --ni7
t.O "5"13 I 6 11 11 7 9 13 9 12
0 7 B 6 8 8 8 7 6 6n
1 --j CC::CCC:l i l
Table B.Den entrance and emergence dates of radio-collared brown bears for the winter of 1981-82 (tiS"is the standard deviation,but it
includes variability from the fluctuating time between observations,as well as variability in denning times).
1981 Entrance 1982 Emergence Days In Den
Bear 10 Sex Min.Max.Mid.Min.Max.Mid.Min.Max.Mid.
280 M 22 Sept.1 Oct.27 Sept.19 Apr.6 May 28 Apr.200 226 213
281 F 1 Oct.7 Oct.4 Oct.6 May 12.May 9 May 211 223 217
283 F 1 Oct.7 Oct.4 Oct.12 May 18 May 15 May 217 229 223
293 M 22 Sept.1 Jun.
299 F 1 Oct.7 Oct.4 Oct.19 Apr.6 May 28 Apr.194 217 206
312 F 1 Oct.16 Oct.8 Oct.12 May 18 May 15 May 208 229 218
313 F 7 Oct.16 Oct.12 Oct.18 May 26 May 22 May 214 231 222
331 F 7 OCt.16 Oct.12 Oct.6 May 12 May 9 May 202 217 210
335 F 1 Oct.7 Oct.4 Oct.19 Apr.6 May 28 Apr.194 217 206
1.0 337 F 1 Oct.7 Oct.4 Oct.18 May 26 May 22 May 223 237 230
-'
,
340 F 7 Oct.16 Oct.12 Oct.19 Apr.6 May 28 Apr.185 211 198
341 F 1 Oct.7 Oct.4 Oct.12 May 18 May 15 May 217 229 223
342 M 30 Oct.19 Apr.4 May 26 Apr.
344 F 7 Oct.16 Oct.12 Oct.19 Apr.6 May 28 Apr.185 211 198
MEAN 1 Oct.12 Oct •.6 Oct.1 May 14 May 7 May --w4 -m ----rr4
tiS"5 7 5 12 9 10 13 8 10
n 13 13 11 13 14 13 12 12 12
-·~e -1 .~J ..~.j i J j j
Table C.Den entrance and emergence dates of radio-collared brown bears for the winter of 1982-83 (,IS"is the standard deviation,but it
includes variability from the fluctuating time between observations,as well as variability in denning times).
'----1 j ~J -----I 1 j 1 )J 1
Table D.Probabilities that annual den emergence or entrance dates were different for individual radio-collared brown bears from 1980
through 1982.The numbers are probabilities calculated by taking the number of days by which the entrance (or emergence)
period from the later year did not overlap the corresponding period from the earlier year,and dividing by the number of days
in the period of the later year.A value of 1.0 indicates no overlap,a value of 0 indicates no apparent difference."_II indicates no comparison was made because of insufficient data.
Entrance Emergence
1980 1980 vs 1981 1981 vs 1982 1980 vs 1982 1981 vs 1982
Bear 10 ~Earlier Later Earlier Later Earlier Later Earlier Later
Males
280 5 1.0 1.0 0.8 0.9
Females
335 1 -0.7
340 2 -0.8
281 3 1.0 0.9 0.5 1.0
344 4 -1.0
313 9 0.8 0.8 *2 1.0 1.0 *5 *6
312 10 -0.3 *4 -1.0 *5 *7
\0 Iw283121.0 *1 0.9 0.3 1.0 *5 *7
337 12 -1.0 *4
299 13 1.0 *3 0.9 0.8 0.9 *6
*1 Entered 1981 den with cub(s).
*2 Entered 1982 den with cub(s).
*3 Entered 1980 den with year1ing(s).
*4 Entered 1982 den with year1ing(s).
*5 Emerged in 1981 with cub(s).
*6 Emerged in 1982 with cub (s)•
*7 Emerged in 1982 with year1ing(s).
,<r:"F"'!
Table E.Mean den entrance and emergence dates of male and female brown bears.("5""is the"standard
deviation,but it includes variability from the fluctuating time between observations,as
well as variability in denning times).
Female Male
"'""mean liS"n mean "s ..n
1980 Entrance Minimum 4 OCt.14 6 13 Oct.N/A 1
Maximum 24 OCt.7 6 27 Oct.0 2
Mid point 14 OCt.12 S 20 Oct.N/A 1
1981 Emergence Minimum 21 Apr.11 6 14 Apr.10 2
Maximum 29 Apr.7 6 26 Apr.6 2
Mid point 24 Apr.9 6 20 Apr.8 2
1981 Entrance Minimum 3 OCt.3 11 22 Sept.0 2
Maximum 11 OCt.S 11 16 Oct.21 2
Mid point 7 OCt.4 11 27 Sept.N/A 1
1982 Eioergence Minimum 3 May 12 11 19 Apr.0 2
Maximum 14 May 8 11 14 May 16 3
Mid point 9 May 10 11 27 Apr.1 2
1982 Entrance Minimum 9 OCt.9 11 13 OCt.10 2
Maximum 27 OCt.16 11 30 Oct.22 2
Mid point 18 Oct.12 11 22 Oct.1''6 2
-
'i""
I
!
,-
I
94
~---,t J J j J j j 1 l j j
Table F.Den entrance and emergence dates of radio-collared black bears for the winter of 1980-81 ("S"is the standard deviation,but it
includes variability from the fluctuating time between observations,as well as variability in denning times).
1980 Entrance 1981 Emergence Days In Den
Bear ID Sex Min.Max.Mid.Min.Max.Mid.Min.Max.Mid.
287 M 9 Sept.29 Sept.19 Sept.30 Apr.5 May 2 May 213 238 212
289 F 9 Sept.29 Sept.19 Sept.5 May 15 May 10 May 221 248 235
290 F 1 Oct.9 Oct.5 Oct.5 May 10 May 8 May 208 221 215
301 F 29 Sept.13 Oct.6 Oct.9 May 29 May 19 May 208 242 225
303 M 30 Apr.5 May 2 May
304 M 5 May 10 May 8 May
317 F 9 Sept.29 Sept.19 Sept.5 May 15 May 10 May 218 248 233
318 F 29 Sept.13 OCt.6 Oct.30 Apr.5 May 2 May 199 .218 209
319 M 29 Sept.13 OCt.6 OCt.30 Apr.5 May 2 May 199 218 209
321 F 9 Sept.29 Sept.19 Sept.10 May 15 May 12 May 223 248 236
ID l
U1 322 M 9 Sept.13 OCt.26 Sept.
323 M 29 Sept.13 OCt.6 OCt.6 May 8 May 7 May 205 228 217
324 M 29 Sept.13 Oct.6 Oct.30 Apr.5 May 2 May 199 218 209
325 F 29 Sept.9 Oct.4 Oct.
327 F 9 Sept.29 Sept.19 Sept.8 May 10 May 9 May 221 243 232
328 F 9 Sept.29 Sept.19 Sept.21 May 29 May 25 May 234 262 248
MALES 19 Sept.6 Oct.28 Sept.5 May 12 May 8 May ---n2 ----ml --m
"S"11 7 8 6 8 7 11 15 13
n 14 14 14 14 14 14 12 12 12
J i 1 1 i i -1 1 .~j j J
Table G.Den entrance and emergence dates of radio-collared black bears for the winter of 1981-82 ("S"is the standard deviation,but it
includes variability from the fluctuating time between observations,as well as variability in denning times).
1981 Entrance 1982 Emergence Days In Den
Bear 10 Sex Min.Max.Mid.Min.Max.Mid.Min.Max •.Mid.
287 M 24 Aug.9 Sept.9 Sept.4 May 6 May 5 May 237 255 246
289 F 23 Sept.1 Oct.28 Sept.12 May 18 May 15 May 223 237 230
301 F 16 Sept.22 Sept.19 Sept.6 May 18 May 12 May 226 244 235
302 M 16 Sept.22 Sept.19 Sept.?6 May 6 'May*232 229
303 M 16 Sept.22 Sept.19 Sept.12 May 18 May 15 May 232 244 238
304 M 16 Sept.1 Oct.24 Sept.6 May 12 May 9 May 217 238 228
317 F 9 Sept.16 Sept.12 Sept.12 May 18 May 15 May 238 251 244
318 F 16 Sept.22 Sept.19 Sept.18 May 26 May 22 May 238 252 245
321 F 16 Sept.22 Sept.19 Sept.6 May 12 May 9 May 226 238 232
323 M 22 Sept,.1 Oct.27 Sept.6 May 12 May 9 May 217 232 224
1.0 324 M 1 Oct.7 Oct.4 Oct.4 May 6 May 5 May 209 217 213I'O"i
327 F 16 Sept.22 Sept.19 Sept.12 May 18 May 15 May 232 244 238
329 M 22 Sept.1 Oct.27 Sept.12 May 18 May 15 May 223 238 230
343 M 16 Sept.22 Sept.19 Sept.12 May 18 May 15 May 232 244 238
346 M 9 Sept.16 Sept.12 Sept.?6 May 6 May*239 236
348 M 16 Sept.22 Sept.19 Sept 4 May 6 May 5 May 224 232 228
349 F 9 Sept.16 Sept.12 Sept.?6 May 6 May*239 236
325 F 9 Sept.16 Sept.12 Sept.
328 F 16 Sept.22 Sept.19 Sept.
MEAN 15 Sept.23 Sept.19 Sept.9 May 13 May 11 May -----n7 ------r4U ----n4
"S"8 7 6 4 6 5 9 9 8
n 19 19 19 14 17 17 14 17 17
*Dates were designated from a point value rather than a time period,because a more accurate mean emergence date was produced.
---1 i J -1 i j j 1
Den entrance apd emergence dates of radio-collared black bears for the winter of 1982-83 ("S"is the standard deviation,but it
includes variability from the fluctuating time between observations,as well as variability in denning times).
28 Sept.6 OCt.2 Oct.
29 Sept.20 Oct.10 OCt.
20 Sept.29 Sept.24 Sept.
6 OCt.15 OCt.10 Oct.
20 Sept.29 Sept.24 Sept.
6 Oct.15 OCt.10 OCt.
29 Sept.6 OCt.2 OCt.
6 OCt.15 Oct.10 OCt.
29 Sept.6 OCt.2 OCt.
6 OCt.20 Oct.13 OCt.
6 OCt.15 OCt.10 Oct.
29 Sept.6 Oct.2 OCt.
6 OCt.15 OCt.10 Oct.
6 OCt.15 Oct.10 OCt.
29 Sept.6 OCt.2 Oct.
6 OCt.15 Oct.10 OCt.
6 OCt.15 OCt.10 Oct.
6 OCt.15 OCt.10 OCt.
6 OCt.15 OCt.10 OCt.
6 OCt.20 OCt.13 OCt.
6 OCt.15 bet.10 Oct.
6 OCt.15 OCt.10 OCt.
6 Oct.15 OCt.10 Oct.
29 Sept.6"Oct.2 OCt.
29 Sept.6 OCt.2 OCt.
6 Oct.15 OCt.10 OCt.
29 Sept.6 OCt.2 OCt.
20 Sept.29 Sept.24 Sept.
--
2 OCt.11 Oct.6 Oct...
5 6 6
28 28 28
Table H.
Bear 10
289
303
317
318
321
323
324
327
329
343
346
349
354
357
358
359
\0
-....J 360
361
363
365
367
369
370
372
375
376
377
378
Sex
F
F
F
F
F
M
M
F
F
M
M
F
F
M
M
M
M
F
F
M
F
F
F
F
F
F
F
F
MEAN
"S"
n
Min.
1982 Entrance 19~9--Emergence
Max.Mid.Min.Max.Mid.
Days In Den
Min.Max.Mid.-----,.,--
11J ------j ---)----J i
Table I.Probabilities that annual den emergence or entrance dates were different for individual radio-collared black bears from 1980
through 1982.The numbers are probabilities calculated by taking the number of days by which the entrance (or emergence)
period from the later year did not overlap the corresponding period from the earlier year,and dividing by the number of days
in the period of the later year.A value of 1.0 indicates no overlap,a value of 0 indicates no apparent difference.
"_"indicates no comparison was made becausE.:of insufficient data.
1980
Bear 10 ~
1980 vs 1981 1981 vs 1982 1980 vs 1982
Earlier Later Earlier Later Earlier Later
Entrance
Males
323
343
324
303
346
287
304
2
4
5
8
8
10
10
0.8
0.0
1.0
0.3
1.0
1.0
1.0
1.0
0.0
0.2
Emergence
1981 vs 1982
Earlier Later
0.7
0.5
1.0
0.5
0.3
1.0
00
Females
349
318
327
328
301
317
289
321
325
3
5
5
6
7
7
9
10
11
1.0
0.0
0.0
1.0
0.0
0.0
1.0
*
*
**
**
*
0.2 **
1.0
1.0
1.0
1.0
0.6
0.8
0.0
0.0
0.2
1.0
0.9
0.2
0.7
1.0
1.0
***
***
0.5
0.5***
*Entered den in 1980 with cub(s).
**Entered den in 1981 with cub(s).
***Emerged from den in 1981 with cubs.
Table J.Mean den entrance and emergence dates of male and female black bears.(liS"is the standard
deviation,but it includes variability from the fluctuating time between observations,as
well as variability in denning times).
Female Male
mean IISft n mean itS"n
1980 Entrance Minimum 18 Sept.11 9 21 Sept.11 5
Maximum 4 OCt.6 9 9 Oct.7 5
Mid point 26 Sept.9 9 1 OCt.8 5
1981 Emergence MiniIilUm 8 May 6 8 2 May 3 5
Maximum 16 May 9 8 6 May 2 6
Mid point 12 May 7 8 4 May 3 6
1981 Entrance Minimum 15 Sept.5 10 15 Sept.*10 9
Maximum 22 Sept.5 10 24 Sept.8 9
Mid point 19 Sept.6 10 19 Sept.9 9
1982 Emergence Minimum 11 May 4 7 7 May 4 7
Maximum 17 May 6 8 10 May 5 9
Mid point 14 May 5 8 8 May 4 9
1982 Entrance Minimum 1 Oct.6 19 4 OCt.3 9
Maximum 10 OCt.7 19 14 Oct.5 9
Mid point 5 OCt.6 19 9 OCt.4 9
*Bear number 287 entered its den very early between 24 August and 9 September.
99
_._~-_.~~--_.-~-----------------."...----