OF T 0 1 iiCT 0135 .;VATI0N
JO1PAf:.ISji
TC1.NI.0 .:;S
COLWBIAN
01-
BLACK-TILr L
2
WILLIA
V'EST
'-2
i.
0
HINES
A TJi. IS
subiitted to
01 ...iGOi'
STATE 1IVSITY
in partial fulfillment of
the requirements for the
degree of'
'..
A
r'r'.
June 1961
JN
APPROV'D:
Redacted for privacy
Associjate Prol(essor of Fish and Uame Ivianagemen
In Charge of Major
Redacted for privacy
Head of Department of Fish and Game Management
Redacted for privacy
hairmaroJradu
ommi t tee
Redacted for privacy
Dean of Graduate Sohoo
Date thesis is presented______
Typed by Sylvia Anderson
ACKNOWLI.GiTS
Perhaps the r.ost important outcome of a student's
research is not in the results he obtains but rather in
the knowledge he gains while conducting his investigation. This knowledge is often imparted or stimulated
by those with whom the student has conferred. The
author is greatly indebted to the following individuals
and organizations for their generous assistance:
Arthur S. Elnarsen, Leader, L. Francis Schneider
and William C. Lightfoot, Assistant Leaders, Oregon
Cooperative Wildlife Research Unit, for the privilege
of conducting this investigation and for guidance,
field assistance, and manuscript reviewing.
Dajor Professor Lee W. Kuhn, Department of Fish and
Game Management for his ;uidance and thesis assistance.
Professors Foland . Iiniick, Department Head, and
Charles E. Warren, Department of Fish and Game Management
and Charlas E. Poulton arid Donald W. Hedrick, Departnent
of Range Management, Oregon State University, for their
advice on ways to improve this thesis.
Lyle D. Calvin, Agricultural Experiment Station
Statistician, for his advice on analytical procedures.
Francis F. Ives, Oregon State Game Commission
District Agent, for his field assistance and stimulating
attitude.
All graduate research assistants from the Oregon
Cooperative Wildlife Research Unit for their cooperation
throughout the study.
Mr. and Mrs. Fred Auer and Mr. and Mrs. Ross Dockins
of the Oregon State Board of Forestry for making living
conditions more pleasant while working in the field.
The Willamette Valley, Oregon Pulp and Paper, Pope
and Talbot, and the I. P. iller lumber companies and
the Oregon State Board of Forestry, the U.S. Forest
Service, and the Oregon State University School of
Forestry for granting permission to use their lands for
this study.
Foresters associated with these organizations were exceedingly cooperative in furnishing information.
OF ONTT
TAIL
I9OiUCTIUN .
.
.
.
,
.
wT}oLs AND f.oCTtmS.
Study Areas
.
1
..... .......
3
.
.
.
.
.
a
Sampleloutea .
.
.
.
.
.
.
.
.
,
.
.
.
.
Observational Procedures
root Method . . . . .
.
.
.
.
.
.
.
.
.
. ....... .
*
.
.
.
.
.
.
.
.
.
.
.
,
.
.
.
.
.
.
.
.
.
SpotlL::htMethod..........a..
SpotlightTests.
F- --SULTS
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
a
. a... .
10
.
a
. .... ...... is.
SpotlightMethod ..............
SpotlightTests.
Effects of leer Activity Changes upon
Counts . . .
.
.
.
.
.
.
,
Effects of Population Shifts and
Increases upon Counts , . . . . . .
Effects of Vegetation Changes upon
Counts
.
a
.
*
.
,
.
a
a
.
a
.
a
a
a
a
,
a
,
12
12
14
,
.
18
.
.
$0
38
'
Foot ethod . a .
a
.
a
a
'
a
a
Effects of Deer Activity Changes upon
Effects of Pooulation Shifts and
Increases upon Counts
.
.
.
.
.
Effects o Ve&;etation Changes upon
Counts .
a
.
.
a
a
,
3
4
8
6
9
.
.
a
a
.
.
.
.
.
39
41
*
44
46
,Ia.sas
Comparison of Spotlight and Foot
SamplingResults
SiY AWL Ci:CLUSiOS
BIBLAUO;.A?HY a
Ay.
,
,
.
,
a
a
a
.
.
.
.
.
.
.
a
a
a
.
a
a
.
.
.
.
a
,
a
a
.
.
.
.
47
50
5*7
LIST OF TABLS
1
2
Distribution an.d Description of Foot
and Spotlight Routes . . . . . a . .
7
a
Maximum Pistance
in Miles that
yeshine Could be
Observed by Various Spotlights .
Simu1td Deer
3
4
5
6
7
8
.
.
13
of the Maximum Distances
in Yards that Doer Antlers Could be
Recognized with Various Spotlights . .
.
15
A Summary of March through April, 1957,
Spotliht Counts from Three Routes in
the Adair and McDonald Areas a . a a a a
16
.
.
A
Results of Weekly Spotlight Counts
from Seventeen Routes between May and
September,l957 ............
17
Monthly Percentages of Classified
Deer Observed Bedded . . ' . a a
a
23
Comparison of Early and Late Deer Counts
Obtained from the Same Routes each
Night by Two Observers a a a a a a a
29
F.esulte of Weekly Foot Counts between
ay and September, 1957 a a a a a a a
40
LIST OF FIGU1 .S
Figure
I
2
Locations of seven study areas within
Benton nd Polk Counties, Oregon . . .
4
5
6
7
.
.
.
. .,,.....
24
Sums of movin average day and night
mean route counts for ten segments
ofthelunarmonth.,.........
26
A spotli;hted two-year-old doe which
was ear-taj:ed with "Scotchlite8
reflect1v eheettn to study nocturnal
moverents of black-tailed deer . . . .
.
31
Mean monthly deer counts for three
recently logged areas with southern
.
a
.
.
.
.
a
a
s
.
exposures
a
a
33
A comparison of monthly 4 p.m. mean
temperatures with the sums of the
monthly mean spotlight route counts
.
.
34
a
a
Monthly day and night percentage of
fawns in the total deer classified
byage
8
5
Monthly comoosition percentage of
mature male deer observed during the
dayandniht. .
3
.
a
a
a
a
.
.
.
a
a
a
A comparison of coefficients of
variation for eleven routes which wore
repeatedly sampled by the spotlight and
footniothods.....,..... ...
48
LIST OF APPENDICES
Appendix
A
B
Weekly schedule of spotlight and
foot route sampling from May 6 to
September2l,1957..........
57
Descriptions of seven lamps tested
.
.
.
on a spotlight range .
.
58
.
.
59
A summary of spotlighted deer sex
and age classifications obtained
between May and September, 157 .
.
.
61
Summary of ni.ht deer activity
observed while spotlighting between
.
.
.
May and September, 1957 .
.
.
62
$eptember,1957 ...........
63
A moving average analysis of lunar
effects upon night spotlight counts.
64
A summary of deer sex and age
classifications obtained from foot
routes between May and September, 1957
65
.
C
.
.
.
.
.
.
.
.
.
.
.
.
F
G
H
.
Eorizontal beam spread measurements
for seven lamps taken at twenty-five
yards.
D
.
.
*
.
Atmospheric conditions present while
spotlighting routes between May and
Atmospheric conditions present while
conducting weekly morning and evening
foot route counts between May and
September,l95?............
66
COi.:A I)N UT TO TI
i
C
II S 10
u
AI
'CT OBS:.t VATION
CULL BIA', BLACK-TATL'D
I:;i: IN wsTrN OF.GON
INTJ ULU CT ION
This investigation, under the auspices of the Oregon
Cooperative Wildlife Research Unit,1 concerns the study
of two direct observation techniques for enumerating
Columbian black-tailed deer, Odocoileus hemionus
columbianus (Richardson), in Benton and Polk counties of
Western Oregon.
The objectives of this work were:
(1) to compare the results of a daytime foot sampling
technique with a nighttime spotlight sampling technique
and (2) to study fluctuations in sampling results in
relation to deer habits and other possible influencing
factors.
Field investigations began March 1 and
terminated September 21, 1957.
Direct observation methods for obtaining big game
population trends are based on the assumption that
annual fluctuations in animal densities can be detected
by yearly changes in the number of individuals observed
by adequate sampling techniques.
The most suitable
technique for obtaining these observations would be one
1.
Oregon State Game Commission. United States Fish and
Wildlife Service, Wildlife Management Institute,
Agricultural Research Foundation, and Oregon State
University cooperating.
which, if used on the same population, gave the least
variation in animal numbers with repeated sempling.
A thorough understanding of deer habits is an essential
basis for developing inventory techniques.
The two
methods were tested under all prevailing weather
conditions to study deer habits and their influences
upon sarnoling results.
MbTLOLS AND ?vOOL.I. S
Study Areas
Preliminary sampling in the fall and winter of
1956 was conducted on the Adair Tract and in the
McDonald Forest of
enton County, Oregon.
Most of the
old growth timber was logged from these areas more than
30 years ago, and advanced stages of second-growth
timber are now found on most forest sites.
Recent
timber sales have been limited and selective cutting
units have been small.
Other areas, representing earlier stages of forest
succession were visited in April, 195?, to select
additional areas for testing the spotlight and foot
sampling techniques.
Consideration was given to the
following factors in judging the desirability of each
area:
(1) they should be heterogeneous in respect to
one another, but with each being typical of a Western
Oregon deer habitat; (2) vehicle access should be
possible by May; (3) the areas should be no more than
one and one-half hours traveling distance apart; and
(4) the areas should be subject to a minimum amount of
human activity.
Five additional areas were selected oil
the basis of this survey.
The locations of all areas
used throughout the spring and summer studies are shown
in Figure I.
Sample Toutes
All routes within an area had to be near one
another' to allow maximum time for sampling.
Each foot
route followed the same course that was spotlighted.
The maximum length of routes tested by both methods
could not exceed the distance that could be effectively
observed on foot during the four and one-half hours
following daylght.
Each week a total of 28 samples was obtained with
the two methods under investigation.
The weekly
sampling of eleven foot routes covered an observation
distance of approximately 35 miles, with the individual
transects varying from 1.0 to 5.5 miles in length.
Six
mornings and four evenings each week were spent sampling
on foot.
Only one route was walked during a morning or
evening period with the exception of the Skid Creek A
and B routes, whioh were 1.0 and 2.3 miles, respectively
(Appendix A).
These transects were observed on foot
each Friday evening, with Unit A being walked first.
The eleven foot routes were also sampled by the
spotlight method.
Starting in June, six additional
spotlight transects were also sampled.
This gave
weekly saiples for 17 spotlight routes that covered a
DORN P1<.
I
RILEY P1<.
N
MONMOUTHO
MONMOUTH P1<.
PEDEE
t
's__
LEGEND
PAVED ROADS
GRAVEL ROADS
o
.
ISI
23
TOWNS
PEAKS
-
CORVALLIS
COUNTY LINES
STUDY AREAS
PHILOMATH
TON
BE
VIA.
4MARYS
SCALE
1LLLA
lu 8 MILES
Lij
(I
'I
I
1
ALSEA
GREEN P1<.
- -
'
D%SO
BELLF0: TAIN
MONROE
FIGURE I.
LOCATION OF SEVEN STUDY AREAS WITHIN BENTON AND
POLK COUNTIES, OREGON.
distance of 65 miles.
The distribution and description
of each route is given in Table I.
The Green Peak A and B routes were alternately
spotlighted first each Sunday night (Appendix A).
This was done to compare the results of early and delayed
night sampling for the same routes.
Sootlihting along
the 15 remaining routes was kept consistent with respect
to time of night and day of week sampled.
Observational Procedures
Sampling began in the Green Peak area on May 6,
1957.
Foutes in this southernmost area were spotlighted
first each week.
Sampling progressed northward into
other areas as the week progressed.
The sampling proce-
dure involved moving into an area in the evening, spotlir2htin
its established transects that night, walking
its foot transects the next day, and moving on to the
next area where the procedure was repeated.
This weekly
circuit was continued for twenty weeks and terminated
September 21, 195?, one week before the opening of
Oregons general deer season.
Foot Method
Leer feed most actively during the early morning and
Table i:
Distribution and Description of Foot and Spotlight Routes
Hours to
Sample
Route
Lengths
Areas
Routes
Impaired
Visibility
bpotIi,bt
Foot
Spotlight
boot
Ày. Yards
Visible
Left Side
Green
Peak
Green Peak Unit A
Green Peak Unit B
*4.8
*4.8
2.4
2.4
1.3
1.3
2.5
2.0
14.5
9.3
Yew
Creek
Yew Creek Unit A
Yew Creek Unit 8
5.3
5.3
2.0
1.0
4.0
*2.8
132.7
41.7
McDonald
Forest
Soap Creek Burn
Oak Creek Drainage
4.3
5.4
4.3
2.5
1.7
4.0
65.7
Bald
Mountain
Bald Mt. Unit A
Bald Mt. Unit B
Bald Mt. Unit C
3.4
3.3
2.0
3.4
3.3
1.3
1.3
2.5
2.5
Skid Creek Unit A
Skid Creek Unit 8
Rickreail Loop Rd.
*1.6
1.0
2.3
5.5
wind
Creek
wind Creek Drain
Cedar Creek Burn
2.6
*4.6
2.6
Adair
Tract
Berry Cr. Trap Unit
Forest Peak
Soap Creek Pastures
2.2
6.8
2.6
2.2
64.3
34.7
Rickreall
Drainage
Totals
*
Routes approximately
return travel.
2.3
5.5
-
.5
.5
.7
1.0
2.5
1.9
4.0
1.0
2.0
3.0
1.0
3.0
2.0
82.9
86.3
59.3
46.5
29.0
-
14.1
124.5
.5
24.4
33.6
12.7
14.6
Grass
Ferns
Flevational
Changes
x
x
x
x
950-2690
975-1425
1700-2200
-
x
x
x
635-1675
200-1035
x
x
x
x
1000-1750
1000-2300
2610-3245
x
x
350-780
400-1650
400-1950
x
x
x
x
x
x
x
1000-2000
1150-1950
350-550
350-1700
250-275
29.1
length indicated, with counts being made on opposite side oi road while on
A
late evening.
The intensity and duration of mid-morning
and mid-afternoon feeding is variable.
Long transects
were established that required observations from about
5 a.rn. until approximately 9:30 a.m. to detect the
influences which irrsularit1es in mid-morning activity
have upon sampling results.
Sampling teriTinated earlier
in the morning on shorter routes.
Morning transect
lengths varied from 2.4 to 5.5 miles.
Evening sampling
was accomplished during the last two end one-half hours
before dusk.
Foutes varying from 1.0 to 3.4 miles in
length wore walked during this period.
Three of the eleven transects were always walked in
the evening, while another four were alternately sampled
morning and evening.
The remaining four transects were
consistently walked one morning each week throughout the
period of investigation.
The rate of foot travel along
transects varied according to cover density, topography,
and the number of doer observed.
The average walking
speed was 1.2 miles per hour.
Transects were always started from the same point
and walked in the same direction.
A pair of 6 x 30
binoculars was used to search distant terrain and shadow
areas.
All terrain along each side of the route was
scanned in a systematic manner starting at the ridge tops
and working downhill.
Transect boundaries were established along natural
terrain features in situations where routes followed high
ridges and the view was riot restricted by adjacent ridge
This restriction was necessary because in areas of
tops.
unlimited viewing, adequate searches could not be made
of all deer habitat.
Spotlight Method
All spotlighting was conducted from a jeep that was
usually driven in second gear, low range, four-wheel
drive.
The average sootlighting speed was between three
and four miles per hour.
A model 740 Unity, 95,000 candle power sotlight with
a number 4535 General Electric lamp was used throughout
the study.
This lamp produces a horizontal and vertical
beam spread of five and one-half degrees and four degrees,
resoectively.
The lamp filament is covered by a hemi-
spherical mirror which directs all light back to the reflector before it is projected.
This feature provides a
well defined beam with little evidence of side light.
A systematic search for deer was made in all habitat
on the left side of the vehicle.
Thus, the maximum
sDotlight transect width was equal to the effective
distance of the light beam.
The spotlight was continually
operated with a horizontal, short stroke, whiing motion
as a search was made up and down the slopes from the
left vehicle headliht to the taillight.
The same
searching procedures wore used as the spotlight beam
was returned to the front of the vehicle.
1his continuous
searching provided a minimum of double coverage of
habitat at the slow speeds traveled.
The vehicle Was
stopped when a deer or animal eyeshine was Seen.
Leer
sex, age, and activity were classified by using $ x 30
binoculars.
Spotlight Tests
A spotlight range was established to determine the
suitability of several lights (Appendix B) for counting
deer and to test assumptions concerning the observer's
ability to see and classify deer during different times
of the lunar month.
Circular, convex "lAW Cataphote" highway reflectors,
five-eighths inch in diameter, were mounted in pairs to
simulate deer eyes when sootlighted.
These simulated eyes
were placed three feet above the ground and separated by
one-tenth mile intervals along a one-mile strip.
Additional reflectors were backed by deer antlers to
give the effect of nature male deer.
These were placed
at 50 yard intervals along a Z0O yard line extending
from the spotlight.
The horizontal beam spread intensity of each light
was measured at 25 yards from the light.
Foot candle
measurements were taken with a Weston, Model 756 street
light meter at one foot intervals along a plane at right
angles to the light beam.
RESULTS
Spotlight Tests
Table 2 shows the maximum distances which simu1ate
deer eyeshine could be observed by seven different
spotlights during full and no moon conditions.
Lamps
1484 and 4516 were inferior because they could not
produce observable reflection at distances equal to the
other lamps tested.
Measurements of beam spread
intensities (Appendix C) showed that these two lamps did
not project a narrow beam of concentrated light.
A
concave mirror in front of the lamp element in lamps
4435, 4535, and 4522 projected all light back to the
reflector before it was projected in a narrow beam.
These lamps produced highest candle power readings
at 25 yards (Appendix C).
Lamp 4522 was designed as
an aircraft landing light and is not suitable for deer
spotlighting because of its high wattage requirements,
short life expectancy, and intense heat production.
Table 2 indicates that the two extremes of no
moon and full moon bad no effect upon the distance which
simulated deer eyeshine could be seen with the naked eye
or optical equipment.
Wall (48) states, "I fee]. quite sure that your
counting more deer under Lull-moon than under no-moon
13
Table 2
Maximum Distances in Miles that Simulated Deer
Eyeshine Could be Observed by Various Spotlights
No Moon
Full Moø
No.
*Distance
in Ft. to
500 c.p.
1+1+35
lk.9
Light
Naked
lye
l3inoc.
30x
Scope
.5
*9
.9
i.9
.5
.9
12.5
.5
.9.
11.9
5
10.9
.5
6.6
6.0
Naked
Eye
7 x 50
Binoc.
30x
Scope
.5
.9
.9
.9
.6
.9
.9
.9
.5
.9
.9
.9
.5
.7
.8
.7
.9
.5
.7
.9
.1+
.7
.8
.5
.8
.8
.1+
.7
.7
.1+
.7
.8
7 x 50
v.12-16
1+535
v.6
1+522
v.13
v.12..l6
1+515
v.6-8
11+81+
v.6-8
1+516
v.6
Distance in feet from light to 500 candle power.
conditions indicates truly greater acttvity of the deer
themselves.
Theoretically, if moonli:.ht were to have
any significant effect upon the visibility of eyeshine
it should interfere, since it would decrease the
intensity-difference between the glowing eye and its
surrounding.
Since your data go in the opposite
direction, I am sure that no human.visual factor is
involved."
A comparison of the maximum distance which mature
deer antlers could be recognized during full and nomoonlight conditions is given in Table 3.
Moonlight did
not influence the observer's ability to see antlers.
Lamps 4405, 1484, and 4516 appeared to be the least
suited for classifyini doer features because of their
wide beam spreads (Appendix C).
From these data, the
assumption was made that the presence or absence of
moonlight had no effect on the observer's ability to
classify deer sex, age, or activity.
Spotlight Method
A total of 4254 deer were seen while completing
1342 miles of spotlight sampling between March and
September, 1957.
Tables 4 and 5 show the results
f
these night counts while Appendix D gives the sex and
age composition of doer classified between May and
Table 3
A Comparison of Maximum Distances in Yards that
Deer Antlers Could be Recognized with Various Spotli.hts*
Full Moon.
Light
No.
7 x 50
1inoc.
30x
Scope
Naked
Eye
No Moon
7 x 50
inoc.
30x
Scope
141+35
100
200
200
100
200
200
14535
100
00
200
100
150
200
14522
100
250
200
100
200
200
1+515
100
200
200
100
200
200
50
200
200
100
200
200
50
200
200
50
150
200
50
150
150
50
150
150
14516
*
Naked
ye
Simulated deer eyes were backed by deer antlers and placed at 50
yard intervals.
16
Table k
ri1, 1957 Sot1i;ht
A Summary of March through
Counts from Three outos in the Adair and McDonald Areas
Oak Creek Drainag
Date
Soap Creek Burn
Forest Peak
Date
Counts.
Counts
Date
Counts
3/1
13
3/26
'+3
3/2
23
3/9
8
k/k
'+5
3/12
20
/li
8
k/6
3/19
12
3/1k
17
k/il
27
'+/2
11
3/21
25
k/18
53
k/il
25
3/22
8
14/19
5k
'+/i5
1k
3/28
10
14/23
17*
'+/i7
7
17
'+/25
60
14/22
19
k/8
16
k/29
k/27
19
4/13
1k
k/17
20
k/2
1k
'4/28
10
Total Deer
180
Observations taken during fog
386
weather,
150
Tah3e 5
eek1 y Spotlight ounta frcm Seventeen
Routes betreen May and September, 1957
fle;iüt; of
pot1ight_Routes
weeks
1
2
5
6
7
3910
Green1eakUnitA
GreenPeakUnitB
6io8ki533
911
7191015
Ye.iCreekUnitA
252710111220101211
Yew Creek Unit B
Soaj Creek Buru
2k 20
44 44 32 20 2k 24 18 8
0akGreekDrairage
B1d Mt Unit A
8
17*125
*
-
Fogged in sample
84129
8 11 10 14
1
7
13 15 11
5 9
63 54 26 30 28 37 29 18 1
21 14 19 16 15 12 10 10 7
18 25 22 14 8
6 9 6 13 8
3 4 5 11 11
3 9 6 11 13
a' co
'.O
r4
r4
a'
Total deer
7
*
____3'J
1
31538935k?
4
15
23
31
6
9
5
12
23
2
5
2
*
2
21?
9
1k
20
22
1k
33
23
29
11010
10
693
7
5
1717
16
1k
23
27
13
6
23
3.8
812
14
7
23
9
6
8
7
7
9
27
3
12
6
5
11
7
23
10
8
4
6
30
11
14
6
10
ii
9
28
7
12
14
5
10
5
r4
L(\
0'
r-
co
t
r4
9
17
1
4
4
913
13
16
18
16
911
173
289
259
453
150
138
8
41104235414458976012
10816014331632
2325754
6552242302k82213480
10 12 16
BaldMt.UnitB
BaldMt.UnitC
SkidCreekUnitA
Skid Creek Unit B
Rickreall Mt. Loop
wind Creek Drainage
Cedar Creek Burn
Berry Creek Trapping
Forest leak
Soa Cr. Pastures
*
7
iJ
r-4
r-4
4
r4
.D
u'
a'
,4
r4
0' 0'
o 'o
r4
r4
7
33
10
17
1
14
10
7
21
7
14
4
5
6
6
5
15
7
7
19
6
8
4
1k
34
13
13
4
13
5
t'\
4
17
3
5
9
8
16
5
-
0'
C\
0
('J
r4
r4
r-4
r4
r4
ir
13
35
5
9
4
10
5
0
0
t'.
"\1
r-4
co
r4
*
*
27
8
8
3
4
6
$
Lf\
r4
1k1
594
211
227
92
112
121
September.
Appendix E describes the activity of deer
that could be classified.
The assumption was made that
the sex and age compositIon and the activity of all deer
not classified was similar to the classified results
obtained during all months.
A further assumption was
made that changes in deer activity from the bedded to
standing position would Influence count results.
Thore
fore, changes in the percentage of bedded deer were used
as one criterion for studying nocturnal deer activity.
Effects of Deer ActIvity Changes upon Counts
This study was not designed to evaluate the difficult
problem of factor Interaction.
Single factor reasoning
was used to interpret changes In deer activity.
This
approach to understanding biological phenomena is often
dangerous and misleading.
Changes in daily weather,
seasonal weather, and lunar phase were recognized as
factors which could influence deer activity and thereby
affect sampling results.
Veather conditions were variable during the spring
and summer months of l97.
Foggy and low-ceiling
cloudy weather were common until the middle of July.
Frequently these conditions did not extend into all
study areas.
Appendix F smmarizes by routes, these
conditions as they existed during spotlight sampling.
The percentage of bedded deer was computed from
counts made under clear versus cloudy skies to determine
If this atmospheric difference had a possible effect upon
night activity. All route counts for cloudy and mostly
cloudy weather were combined and conpared with a
systematically selected number of samole counts represeritthg clear and scattered cloud conditions. The
criteria used for determining cloud cover are given in
Appendix F. This comparison revealed that bedded deer
constituted 21 and 18 per cent of the classified deer
for cloudy and clear weather, respectively. Thus, no
importance could be attached to the influence of cloud
conditions upon night activity.
Between March and
September,
twenty-one samples
were taken in the rain. The intensity of precipitation
varied from heavy rain downpours to moderate "fog drip."
The Oregon State University weather station reported that
9.4 inches of precipitation fell during March and April
with 26 days contributIng .10 of an Inch or more
(13, p. 39; and 14, p. 57). During seven nights In this
period, rain was encountered while making night
observations. Late spring and early sunmer precipi-
tation was less, with most of it falling In the fori
of light to moderate rain or heavy "fo drip."
Early spring counts revealed that 80
per cent of
the deer were active during rainy nights.
This figure
approximates the peroentaze which was active for all
weather conditions during the summer months (Appendix
E).
Thus it seemed that rain did not retard early
spring night activity.
Perhaps this was due to the
deer being conditioned by the regularity of rain
throughout the winter months.
Late spring and summer
precipitation was so infrequent that its effects upon
night activity could not be evaluated.
Vtthen a route or a portion of it was tfogged_in,fl
deer counts were not comparable to those obtained when
visibility was not restricted.
Under foggy conditions,
the spotlight beam penetration was sometimes greatly
restricted.
"Fogged-in" counts were made only for the
purpose of studying doer activity.
These counts were
not included in the comparison of the two census methods
results.
Foggy weather conditions, with an absence of wind,
did not seem to retard deer activity.
Only 16 per cent
of the deer were bedded under such conditions.
However,
some 35 per cent were bedded during foggy and windy
weather.
This aug.
eta that wind may influence deer
activity.
The three categories of "no wind," "breezy," and
"windy" weather were used to study the effects which wind
21
velocity was
highly variable at different points along each route.
seemed to have upon deer activity.
A subjective estimate was
!nade of
wind
the average air turbu-
lence for each route sampled by classifying it into one
of the three categories.
The sums of mean route counts for the "no wind,"
"breezy," and "windy" categories were 132, 108, arid 9?,
respectively. These results were obtained from the
samplings of ten routes that were spotlighted between
The Student's "t" test indicated
that a significant difference, at the five per cent
level, existed between the results of the "no wind" and
May and September.
"windy" counts.
Deer apparently preferred the leeward slopes during
windy weather. This was particularly noticeable during
the first part of the study when winds tended to
accentuate lower temperatures. A leeward preference was
less noticeable during the late summer months when night
temperatures were warmer.
No correlation existed between the percentage of
bedded deer and the air temperature recorded at the
beginning of each sample. This comparison was complicated
by frequent, large temperature differences encountered
during the sampling of routes on which there were large
changes in elevation, Table I.
The weather was cool, and cloudy with considerable
precipitation in W;arch.
A higher frequency of clear
warm days occurred as spring progressed into suner.
The average daily maximum temperature increased to
about BC degrees Pahrenheit by September.
Even though
the maximum temperature increased greetly, the average
monthly minimum temperature did not increase more than
10 degrees Fahrenheit.
These increased daytime and
relatively stable nighttime temperatures suggested
that a seasonal day to night change in feeding
activity might affect the results of night counts.
Small differences existed between the monthly
percentages of bedded deer, Table 6.
Normal variation
or better springtime ground visibility nay have been
realonsible for the slightly higher percentages
observed during the spring months.
No changes in
seasonal night activity could be detected through a
comoarison of monthly fluctuations in bedded mature
and yearling deer number.
Here, the assumption was
made that the seasonal activity habits of all sex and
age classes, exclusive of fawns, were the same.
Mature male deer were observed to change their daily
activities as the suriirner progressed.
Increases in night
observations of bucks occurred in the late summer while
at the same time fewer bucks were seen during daytime
This suested that nocturnal
sampling, Figure 2.
buck activity was greatest during the late summer
months.
Dasmarn (2, p. 145) in his studies of b1aek
tailed deer in California, states that, 'Durthg late
July and early August bucks are less evident.'1
Ha
continues by saying that the older msles move into
heavy cover about the time their antler velvet begins
to shed.
It was difficult to classify yearling deer by sex
and age at night.
Sex identifIcation was hindered by
the fact that eyeshine tended to obscure small antlers
when they were present.
On the Adair Tract and
Mconald Forest either-sex hunting area, Hines (6, p. 7)
found that fully developed yearling antlers varied from
one to nine inches in length,.
It was thus impossible
to classify enough yearlin.s to study their nocturnal
habits as a group.
A lunar month may be defined as the period from
new moon to new moon,
According to Jones (7, p. 76)
its mean length is approximately 29.5 days while the
actual length nay vary considerably from the mean
value.
The name, lunar phases, is cormected with the
variations in the
visible outline.
Waxing and
waning refer to respective increases and decreases in
the visible outline which occur before and after a full
Table 6
Monthly percentages of Clas.ified Deer
Obaerved i3edded
Months
No. Standing
No. Bedded
Per Cent
*
March and
April
May
June
July
371
221
268
23
300
223
78
61
52
58
91
k7
21.1
21.6
16.3
19.3
23.5
1?.k
5xc1sjve 0t fawns
August
September
24
35
30
25
w
4
I-
2O
0
Lu
'5
5
I]
JUNE
JULY
AUG.
SEPT.
MONTHS
FIGURE
2.
MONTHLY
COMPOSITION PERCENTAGE OF
MATURE MALE DEER OBSERVED DURING THE DAY AND
NIGHT (EXCLUSIVE OF FAWN OBSERVATIONS).
25
moon, respectively.
There is a conimon belief that deer restrict their
diurnal activity during the middle of lunar month when
night illumination is the greatest.
It is contended
that moonlight either stimulates or allows prolonged
nocturnal activity to occur, and this results in less
diurnal activity.
All spotlight results were classified into ten,
three-day segments of the lunar month.
Analysis of
variance was used to determine if differences existed
in the results of these ten phases, which showed higher
counts during the second and third quarters of the
lunar cycle (8, p. 227).
A significant difference,
at the five per cent level, existed between these
results, which were weighted for this test.
Analysts
of variance also indicated that there was a difference,
at the five per cent level, between the number of
standing and bedded deer observed in the above ten
lunar month segments.
A moving average analysis was also used to comare
the sampling results obtained under different phases of
the moon.
Appenix G presents the computations for
this analysis, while Figure 3 presents these results
graphically.
This analysis supports the conclusions
of the previous tests.
Leer seemed to be most active
LUNAR SEGMENTS
1-15
4-lB
7-21
10-24
13-27
16-30
19-3
22-6
25-9
28-12
19
18
U)
I
z
D 17
0
C)
LU
f- is
0
z
LU
Li..
0
14
U)
U)
12
IC,-
FIGURE 3. SUMS OF MOVING AVERAGE DAY AND NIGHT MEAN ROUTE COUNTS FOR TEN
SEGMENTS OF THE LUNAR MONTH.
at night during the middle of the lunar month, when
illwination was the greatest.
This accelerated
activity aoeared to cause siynificant increases in
spotlight counts,
Many investigators recognize nocturnal movements
as part of a deer's daily cycle, but they rarely
discuss them in relation to moon ohases (12, p. 149,
558; 4, n.
9, and 5, p
213).
Linsdale, however,
found that moonlight did not regulate nor was it
essential to foraging and other movements of blacktailed deer (9, p. 122).
In Finland, Slivonen
(11, p. 20) found that, "Preliminary control experi
ments suggest the probability of a stimulating effect
of moonlight upon the nightly activity of animals."
Changes in deer activity during the night could
effect the results of repeated route counts
accomnlished at different hours.
Counts in brushy areas
would be most influenced by such changes since bedded
deer would be more difficult to deteot than standing
animals.
A time difference existed between the sampling of
the first and last route each night.
The Fiokreall
route was completed the latest, with observations
terminating about 2 a.m.
Totals of about 1500 deer were observed during
the seven earliest and seven latest samples taken each
week. Bedded deer comprised 22.4 per cent of the
earliest and l.4 per cent of the latest counts. Thus,
no appreciable change in deer activity was detected
before the predawn hours.
In the late summer, a second observer was used to
spotlight the same routes a second time each night.
These predawn counts were about one-thrd lower,
Table 7, with 55 per cent of all classified deer
bedded.
Bedded deer constituted only 25 per cent of
all deer classified during the first nightly counts.
This suggested that a retardation of predawn activity
did occur and that this decrease in activity tended to
reduce the number of deer seen.
In support of this theory, Linadale (9, p. 268)
reports that there may be no black-tailed deer activity
in the open between midnight and daylight. Halloran
found that white-tailed deer commonly feed at all
times of night during the late summer. Taylor
(12, p. 150) cites Fuff (10, p. 26) as saying that
white-tailed deer, Odocoileus virginianus vlrginianus
(Zimmerman), have been known to feed until near midnight.
He continues by saying that some individuals are active
a greater part of the night but that there appears to
be a period of night inactivity just as in the daytime.
Table 7
A Comarison of Early and Late Deer Counta Obtained
from the Same Routes Each Night by Different Observers
Spotlight Routes
Cedar Creek burn
md Creek Drainage
Rickreall Mt. Loop
Bald Mt. Unit C
Nald Mt. Unit B
Bald Mt. Unit A
18th Ueek
Early
Late
8
8
27
1
0
8
6
16
13
0
3
0
Oak Creek Draina;;e
Soap Creek Burn
Yew Creek Unit B
Yew Creek Unit A
Green Peak Unit 3
Green Peak Unit A
Total Deer
-
Fogged in
19thJoek
Late
Early
Late
1k
11
30
3
12
13
5
12
7
k
6
21
1
7
9
2
23
18
13
5
7
52
38
2OUi..:eek
Early
1k1
0
3
6
2k
28
k
2
7
11
16
0
3
5
3
25
6
18
16
12
11
12
7
5
13
6
5
6
113
l4O
88
30
ffects of Population Shifts and Increases upon Counts
Population shifts acpeared to be one of the most
important factors causing fluctuations in weekly counts.
Here, population shifts describe movements of animals
into and out of open areas whore changes in their numbers
could readily be recognized.
In general, the home range of black-tailed deer
was observed to be small In size.
contained numerous
Instances
Daytime sight records
where the same Individuals
or groups were repeatedly seen within restricted areas,
oftentimes no larger than five acres In size.
In the winter of 1956-5?, several deer, along the
Berry Creek route, were live-trapped and ear-tagged with
circular aluminum tags covered with 'Seotohlite1'
reflective sheeting, }lgure 4.
Night observations of
these tagged deer suggested that their home range was
small during the summer months.
The greatest observed
movement occurred when two individuals shifted their
activities about 400 yards from a rapidly drying forb
and grass opening to a small area containing volunteer
legumes and remnant fruit trees.
A frequency distribution of all sight records for
each route, by one-tenth mile Intervals, revealed that
the most important population shifts affecting route
71
FIGURE 4.
A SPOTLIGHTED TWO-YEAR-OLD DOE WHICH WAS EAR-
TAGGED WITH "SCOTCHLITE" REFLECTIVE S}ETING TO STUDY
NOCTURNAL MOVEIVENTS OF BLACK-TAILED DEER.
counts occurred from relatively open south slope areas.
Leer were concentrated in these areas during the spring
when warmer temperatures and a greater abundance of forb
and grass forage were present.
Frequency distribution
data indicated that population dispersals occurred from
these areas during June and early July.
Figure 5 shows
the mean monthly sotlight counts for three such areas.
Perhaps earlier maturin
vegetation and higher
temperatures on south slopes influenced population
shifts from these areas.
The mean monthly 4 p.m. temperatures were plotted
and compared with the sums of mean monthly route counts
to further study the effects which temperatures had
upon total counts.
These temperature data were recorded
at the Oregon State University Hyslop Agronomy Farm in
the \Nillamette Valley.
given in Figure 6.
A comparison of these data is
It can be seen that an inverse
relationship exists between late afternoon, or near
maximum temperatures, and the sums of mean monthly deer
counts.
Care should be taken not to interpret Figure 6 as
meaning that there were fluctuations in night activity
which were caused by temperature differences and
resulted in higher or lower counts.
The suggested
implication is that temperature fluctuations wore in
25
2
0
0
a:
15
LiJ
0
>-J
I
2
0
2
I0
w
[.J
APR. 30 MAY 31
JUNE30 JULY 31
AUG. 31
SEPT.21
MONTHS
FIGURE 5.
MEAN MONTHLY DEER COUNTS FOR THREE
RECENTLY LOGGED AREAS WITH SOUTHERN EXPOSURE
SLOPES.
COUNTS.
ROUTE
SPOTLIGHT
MEAN
MONTHLY
THE
OF
SUMS
THE
WITH
P.M.
4
MONTHLY
OF
COMPARISON
A
MEAN
TEMPERATURES
6.
FIGURE
MONTHS
21
SEPT.
31
AUG.
31
JULY
30
JUNE
65
70
Z
75
w
80
cZ
85
165
°'
170
¶2
'75
Iw
180
85
some way related to population shifts which caused
seasonal differences in route counts.
Significant increases in deer numbers occurred in
the late spring with the 1957 fawning season.
It was
necessary to study the Influences which this population
increase had upon night counts.
Total monthly fawn
counts and classified fawn actiTity data were used as
indices for determining nocturnal fawn behavior and its
effects UDon total counts.
The first new-born fawn was seen in the Wind Creek
drainage on the morning of May 25, 195?.
It was believed
that the fawning season peak occurred during the first
week of June.
This was based on the observed decline in
frequency of does with distended flanks.
The last
pregnant doe was seen along the Oak Creek route on
July 30, 1957.
Her genital region was enlarged, suggesting
that her fawning time was near.
Spotlighted fawns were usually observed bedded
during the first weeks after the peak of the fawning
season.
During June, only in four instances was a doe
not in the near vicinity of each fawn seen.
In July,
mature does were more frequently observed feeding alone
or with groups of deer that contained no fawns.
The
fawns were usually seen by themselves, either bedded or
stand thg.
In early August the night doe-rawn relationship was
similar to that of July.
The does, fawns, and frequently
yearlings, ciere united into distinct family groups during
late August and 5eptember.
The percentage of fawns, from all deer classified
each month, was used as an index to study night fawn
activity.
It will be seen that the percentage of fawns
remained stable until September, suggesting that night
fawn activity, Figure 7, dId not accelerate until late
summer.
Here, the assumption is made that significant
increases in fawn movements, from the bedded to standing
position, would be reflected by the proportion of fawns
seen in all deer classified by age.
The observed increaso in night activity of fawns and
mature bucks did not cause increases in weekly counts.
Average weekly counts for three week intervals, during
the last twelve weeks sampled, ranged between 163 and
170 deer.
Here a ratio estimate technique was used to
predict three missing sample values by utilizing all
results obtained by both methods.
Population shifts,
deer dispersals, and vegetation growth tended to reduce
sampling results as the summer progressed.
These changes
prevented late summer counts from being higher than
spring counts, even though the fawn additions increased
the population.
35
30
U,
z
Ui
0
25
20
z
Ui
C-)
Ui
5
JUNE
JULY
AUG.
SEPT.
MONTHS
FIGURE
7.
MONTHLY DAY AND NIGHT PERCENTAGE OF
FAWNS IN THE TOTAL DEER CLASSIFIED BY AGE.
Iffects of Vegetation Changes upon Counts
Early spring deciduous shrub and tree growth
hindered the spotlighting of some slopes that were highly
visible during the winter.
Leaf growth on species such
as vine maple Acer oircinatum Pursh.,1 big leaf meple
Acer macrophyllurn Pursh., ocean spray Holodiscus
discolor Pursh., thimbleberry Rubus parviflorus Nutt.,
sairnonberry Bubus spectabilis Pursh., hazel Corylus
californica Pose, Oregon alder Alnu
oregona Nutt.,
and Oregon oak Quercus garryana Dougl. began to conceal
the presence of deer and their activities.
This growth
became evident in mid-April at low and medium elevations.
It was well developed by the end of May.
At higher
elevations, spring growth was about two weeks later in
gaining its full complement.
Further restrictions in visibility came when
herbaceous vegetation reached several feet in height.
This followed the initial deciduous shrub and tree
growth.
Bracken fern, Pteridium a4uilinum pubescens
Underw., was the most abundant species.
it grew to a height of six feet.
In places,
At medium and low
elevations fronds of this fern opened during May, while
1.
6
Abrams's (1955) Illustrated Flora
acifie
States was used to identify all plant species.
on the higher slopes this development was not reached
merata L.
until June. Tall grasses such as Lactylis
and Jlus laucus Bucki. also started to conceal the
presence of deer in open areas by late May.
Growth of herbaceous roadside vegetation progressively restricted the distance which could be spotlighted as the summer progressed. Table 1 shows those
routes which contained considerable amounts of this
interfering vegetation.
Deer counts took an appreciable drop In May as may
be noted by conmaring the early spring counts given In
Table 4 with the same route counts given In Table 5.
This suggests that in May vegetation growth was one
factor contributing to the decline in sampling results.
Foot Method
A total of 2198 deer was seen during approximately
650 miles of daytime foot sampling. Table 8 gives these
observations for May through September. Approximately 35
per cent of all deer wore not classified by sex and age
(Appendix H). This was due to insufficient observation
time, poor light conditions, or inadequate optical
equipment.
Table 8
Results of Weekly Foot Counts betweeu
May and September, 1957
Foot Routes
Green Peak Unit A
GreenPoakUnitB
Yew Creek Unit A
Soap Greek Burn
BaldMt.UnitA
Ba1dMt.UnitB
SkidCreekUnitA
SkidCreekUnitB
Rickreall Mt. Loop
Wind Creek Drainage
Berry Creek Trap Unit
Weeks
May
2 3
*
-
Unsampled
Fogged in sample
July
10 11
4
Seternber
August
1k 15 16
18
19
20
0321*7221365k 1721k
*
k
19
17
2
8
3.
k
0
5
7
7
2
20
7
6
1
*
+6
5
3
5
6
12 5 13
* 29
*
8
0
9
12
13
17
6
1
8
3
k
5
3
7
10
6
9 12
17 27
12
21
3k
13
57
10
56
0
29
16
3k
21
29
39
27
2k
kl
8677611537
562k* 592].812
2k
235690
24O
5k3
1k175
9221k 92
kl3lk 701997 6119
713
12032735621000k
61k983 532 61k ilk 32283
6
58 12 23 1k 22 65 30 22 *
20 7 7 1k 17 7 15 17
0 2 * 5 2
o co
Total deer
June
6 7
C
-
Lf\ 0
r-4
Co
Co
'O
t- tU\ tr-t
\
0'
(7
t-
50
8
+3
37
13
0
3.
1k
6
0
\O
$
r-4
k9
9
1
$
r4
1t\
U'
C'
v-4
rl
*
9
19
6
8
0'
0'
2
8
12
3
5
*
P\
CO
CO
C-
0
0
tf\
U'\
i-4
-I
I
5k5
269
38
1k
0
0
kO
16
22
50
3k
k
29
16
3
k
Co
Lt\
0'
Effects of Leer Activiy Changes upon Counts
Cloudy weather conditions were more common during
daylight observations (Appendix I) than they were during
night sampling (Appendix F).
Most of this cloudy weather
occurred during the first half of the 20-week sampling
period.
This weather caused subdued light which lessened
the contrast between the deer pelage and the surrounding
vegetation.
Deer were more difficult to detect under
these poor light conditions.
Sample counts could not be
used to interpret activity changes in relation to the
presence or absence of clouds because of this varying
visibility of doer.
Leer seemed to forage later into the morning on
cloudy, cool days.
Five times as many deer were seen
along the last two miles of the three longest routes,
Table 1, during the first l
weeks of sampling as
were seen during the last seven weeks.
Deer had
presumably bedded, and were less conspicuous, before
sampling was comleted on the warm days of August and
September,
Deer usually did not start feeding in sunny areas
until near sunset on hot days when the 5 p.m. temperature was near the daily maximum.
foragin
On these evenings,
deer were first observed on shady slopes.
42
Foraging activities commenced earlier in the afternoon
on all slopes when the days were cloudy and cool.
"Windy" weather occurred during 10 per cent of the
197 daytime route samplings, and it occurred equally
on clear and cloudy days.
"No wind" and "breezy" Wind
conditions also occurred equally duiin: clear and cloudy
route samplings.
Sums of moan route counts for the
"no wind," "breezy," and "Windy" categories were 41, 32,
and 27 deer, respectively.
These Liè:ures were obtained
from the sampling results of five routes which were well
represented in all tbree categories.
The sums of the
mean route counts for all 11 routes were 78 and 65 deer
for the "no wind" and "breezy" conditions, respectively.
The Student's "t" test did not indicate a difference
between these data at the Live per cent significance
level.
Insufficient observations durIng windy weather
prevented a comparison of the "no wth&' and "windy"
results for all routes.
Both Dasmann (3, p. 82) and Linadale (9, p. 316)
observed that wind caused black-tailed deer to seek
sheltered spots while Aldous (1, p. 328) stated that
deer seek the protection of heavy cover during 8trong
winds.
Heavy rains occurred on only one occasion during all
foot sampling.
The total deer seen on this evening sample
of the Bald Lountain Unit A route was within the range of
previous counts.
It was not oossible to evaluate the
effects which rain bad upon diurnal activity since the
duration and intensity of precipitation was highly
variable.
Poor light conditions and wet optical equip-
ment lessened the ability to detect deer under these
conditions.
Mature male deer were the only sex and age group,
excepting fawns, observed to change their daily pattern
of activity as the summer progressed.
Figure 2 depicts
the nionthly percentage of mature bucks seen in the
total mature deer classified by sex and ago each month.
There was an appreciable drop in the proportion of buck8
seen during the August and September daytime counts.
Corresponding increases in night observations of mature
bucks occurred during the last two months of investigation.
It is commonly believed that morning deer activity
is retarded following nights of full or near full moon
conditions.
The daytime counts were teatd by a moving
average analysis to determine if there was a relationship between the reoults of foot samoling counts and
lunar chases.
This technique was described in the
previous section dealing with lunar effects upon night
counts.
Figure 3 illustrates the relationship between
the sums of the mean morning route counts for the ten
44
lunar segments treated.
This method of using the same
route means in different combinations revealed that
slightly lower daytime counts were obtained on mornings
following nights with waning moon conditions.
It ws
possible to test for differences between the results of
morning counts by regrouping foot count data into ton
three-day periods of the lunar cycle.
Analysis of
variance indicated that there was no difference between
counts for these ten lunar segments, at the five per cent
significance level.
Effects of
ulation Shifts and Increases upon Counts
High numbers of mature and yearling deer were
observed on the warmer, open., south-racing slopes at the
beginning of the study.
Deer became less evident in
those open areas as summer progressed and temperatures
became warmer.
Three such openings, along the Soap Creek
Burn, Fickreall Loop, and Skid Creek B routes, possessed
a predoninance of low grass cover where deer were easily
recognized.
A May to September reduction in deer
observed within these three route segments ranged from
57 to 80 per cent.
These shifts from the open grassy
areas, though associated with rising sunnuer temperatures,
may have been influenced by changes in deer food
preferences from the maturing herbaceous vegetation
found in the openings to browse species and thoir
associated understory plants found in adjacent areas.
However, it was interesting to note that during the first
two weeks of
ugust, when cool, cloudy weather re-
occurred after several weeks of high daytime temperatures,
there were population shifts back into these three open
areas.
This suggested that perhaps temperature changes
were more influential than food preferences in causing
deer redistributions.
Deer numbers decreased again in
these open areas with the return of warm weather.
The early June fawning season caused sizable
increases in the potential number of deer that could be
sampled.
In early July, these fawns became more notice-
able as they started to follow the does.
Iigure 7 gives
the monthly percentages of fawns seen in all deer
classified by age.
This indicates that early summer
diurnal fawn movements were more extensive than were
nocturnal movements for the same months.
The daytime
percentage of observed fawns increased to about 35
per cent of the total deer classified by the end of the
summer.
Thia firure Is somewhat biased since mature
bucks were less frequently observed In the late summer.
This tended to increase the percentage of observed fawns
for the months of August and September.
The monthly sums of mean route counts for the
eight routes which were observed May through September,
were 102, 9?, 135, 138, and 81, respectively.
The June
count drop to 9? could reflect animal shifts from the
open areas.
The accelerated activities of fawns caused
the sums of monthly moan route counts to peak in August
before dropping to a low of 81 deer in September.
Effects of Vegetation Changes upon Counts
A description of spring and summer vegetation
growth and its effects upon the ability to see deer were
discussed in a previous spotlight section.
Daytime
observations were further influenced by changes in
foliage and deer pelage color.
The color of vine maple
leaves began to change from green to reddish-orange by
midsummer.
This lessened the contrast between the
door's reddish-brown summer pelage and the abundant
vine maple.
this time.
Most grass and forb growth had matured by
This dry herbage also lessened the pelage-
vegetation contrast, which was an important clue to
locating deer in the early summer.
By September, the ability to distinguish motionless
deer became more difficult as they began to molt into
their grey winter pelage.
The mature bucks were the
first to shed their reddish-brown pelage while the
mature does were the last to undergo this change.
Comparison of Spotlight and Foot Sampling Results
This section compares the night spotlight and the
daylight foot methods of observing deer by analyzing the
A co-
variations between their repeated samplings.
efficient of variation, or relative standard deviation,
was omutd from the results of all observations
(exclusive of those obtained on foggy days) for each
Counts from
route sampled by each method of' observation.
morning and evening foot routes were combined because
their results were not significantly different.
Figure 8 compares those coefficients for the eleven
routes which were sampled by both methods.
The results
from nine of the eleven spotlight routes had less
variation between repeated samplings when compared to
daytime results obtained from the same routes.
Previous
sections discuss some of the factors possibly causing
this variation.
A day and night comparison of sums of mean route
counts for the eight routes spotlighted on the left sIde
of the vehicle were 107 and 116 for spotlight and foot
counts, respectively.
This illustrates that approxLmately
the same number of deer were seen while spotlithting the
left side of the transect as were seen along both sides
during daytime sampling.
The sum of the average deer
seen per hour of spotlight and foot sampling on these
1
Z
zrn
-I
G)0
,
oz
(fl-I
-<
a,0
U)
>0
(flfl
-n
QC)
rO
in
rr
rn-0
(0X()
0->
,i
U)
BERRY CREEK
WIND CREEK
SKID CREEK B
SKID CREEK A
RICKREALL LOOP
BALD MOUNTAIN B
BALD MOUNTAIN A
SOAP CREEK BURN
YEW CREEK A
GREEN PEAKB
GREEN PEAK A
cfl
m
o
C
oz
Oi
cji
-
S.
-
'S
o
0
c.n
Ui
a,
I
0
Ui
0
-i
COEFFICIENTS OF VARIATION
Ui
0
a,
UI
a,
0
(0
ei;-ht routes was 66 and 34, respectIvely.
This
indicates that the spotlight routes were sampled in
approximately one-half the time of the foot routes.
GL
StlM.4.'Y AJ
I.?NS
A corperison of two direct ObS-IV&t1Ori net hods of
black-tailed d.er i
enumerat.in
was oonducted under t
'.00perative Viildlif
leaerhi
esearch
e.ten )reon
of the )reofl
nit.
A ni.:ht spotli ht and a day foot observation method
were tested betw,en
resated1y samiin
arch arid September, 195?, by
the same routes.
Weeiy and
seasonal variations in counts were determined for each
method, and attapts were made to establish the causes
of these variations,
Thtals of 4254 and 2198 deer were observed along
niit s?Ctli.it kind daytime Loot routes, resoectively.
The following results were obtained from these
observations
Lffects of Peer Activity Chang
1.
upon 3ounts
iight deer activity was riot influenced by the
presence of cloudy weather.
u.mer daytime
activity was prolonged on cloudy days.
Cloudy
weather resulted in lower daytime temperatures,
and the long! er foot routes had higher counts
along their last two miles on these days.
2.
P1:hest morninc counts were obtained on clear days
when the temperature remained below 80 degrees
Fahrenheit.
3.
The presence of rain did not seem to affect
night deer activity in the spring.
Fain was so
infrequent during daytime counts that its
effects could not be measured.
4.
Viny weather caused significant decreases in
night counts.
Doer tended to 530k the leeward
slopes on these nights.
There was no difference
in daytime counts taken on 'no wind' and "breezy"
days.
5.
Significantly higher night counts were obtained
during the second and third quarters of the
lunar month.
This was at a time when night
illumination was the greatest.
Higher percentages
of active deer were also observed during these
night counts.
Daytime counts were not significantly
different when grouped into lunar month phases.
6.
Higher proportions of mature male doer were observed
during late summer nights.
This increase corres-
ponded with a reduction in the proportion of mature
bucks seen during daylight counts.
'7.
Foute sampling durinc: the predawn hours produced
lower counts than did sampling earlier in the night.
Twice as many bedded deer were seen during the
52
predawn hours.
This suggested that oounts may be
influenced by the time of night sampled.
8.
No difference existed between morning and evening
foot route counts.
Effects of Pooulation Shifts
1.
Increases upon Counts
Early summer population shifts from open south
slopes caused large reductions in route counts.
An
inverse relationship existed between mean monthly
4 p.m., or near maximum, temperatures and the sums of
mean monthly night counts.
This indicated that
population shifts resulted when increased tempera-
tures adversely influenced the deer either directly
or indirectly.
2.
Daytime counts were first influenced by the fawn
increment in July, when fawns started to follow the
does.
Night fawn observations were less frequent
than daytime observations until September, when the
fawns became more active.
Effects of Vegetation Changes upon Counts
1.
Spring and summer vegetation growth tended to conceal
the presence of deer during this study.
This was
undoubtedly responsible for some of the variation
53
between counts.
2.
Seasonal changes in color contrasts between vegetation and deer
elage influenced daytime counts.
Deer were most readily seen on sunny days in the
early summer when the deer pelage was reddishbrown and the vegetation was green.
Animals were
most difficult to see in the late summer when deer
color was grey.
Comparison of Spotlight and F00t Sampling Fesults
1.
Nine of eleven routes had less variation for night
sampling than for day sampling.
2.
Similar deer numbers were seen along the left side
of routes at night as were seen along both sides of
the sa,e routes during the day.
3.
The spotlight counts were accomplished at twice the
rate of daytime foot sampling.
From the results of this study it is recommended
that further tests of the spotlight method be undertaken.
This work should be done in the late winter and early
spring, prior to the onset of spring vegetation growth.
This would eliminate the influence which vegetation growth
has upon the ability to see deer.
Populations would still
be concentrated on open grassy slopes where counting is
easiest.
Also, early spring counts would not be
influenced by the fawn increment.
1.
Conduction deer studies with
Aldous, C1arnce M.
the use of a helicopter. Journal of ildlife
Management 20:327-328.
2.
1956.
Behavior of Columbian black-
Dasmann, P aymond F.
tailed deer with reference to poDuletion ecology.
Journal of Mammalogy.
37:143-164.
1956.
Determining structure in
Columbian b1aok-ii1ed deer pooulstions. Journal
3.
__________________,
4.
of Wildlife Management 20:78-83. 1956.
Gregory, Tappan.
yes in the night. New York,
Thomas Y. Orowell Ccmpany, 1939. 243 p.
5.
Halioran, arthur F. Management of deer and cattle
on the Aransa,s National Wildlife Refuge, Texas.
Journal of Wildlife Manement 7:203-216. 1943.
6.
Hines, William W.
Kill statistics from an
intensively hunted Columbian black-tailed daor
population in estern Oregon. Unpublished
manuscript. 1958. 13 numb. leaves.
7. Jones, H. Spencer. General astronomy. New York,
Longmans, Green and Company, 1923.
386 p.
Li, Jerome C. P. Introduction to statistical
Arbor, Michigan, Fdwards Brothers,
inference.
Inc., 1957. 553 p.
9. Linadale, Jean . and P. Quentin Tomich. A herd
of mule deer. Perkeley, California, University
of California Press, 1953. 567 p.
10. fluff, Frederick J. The white-tailed deer on the
Pisab. National Came Preserve, North Carolina.
Washington, D.C., TJS Forest Service, 1938.
8.
249 p.
11. Slivonen, Lauri and Jukka Koskimlea.
Population
fluctuations and the lunar cycle. Papers on Game
Pesearch.
22 p.
Helsinki, Finnish Game Foundation, 1955.
12.
Taylor, Walter P. The deer of North America,
Harrisburg, Staekpole Company, 1956. 668 p.
13.
u.S. \eather Bureau. Cliniatological data.
Oregon. 63:39.
1957.
14.
_______________
Oregon.
15.
6357.
Walls, Gordon L.
July 7, 1958.
Climatological data.
1957.
Letter, Berkeley, California.
APPI2,NLICFS
5?
APPJNDIX A
eek1y Schedule of Spotli.ht and ?::ot Route
Saiing from May 6 to September 21, 1957
Miles
Day
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Routes
Green Peek Unit A
Green Peak Unit B
Green Peak Unit A
Green Peak Unit a
Yew Creek Unit A
Yew Creek Unit B
Spotlight
SA
SA
Soap
Bald
Bald
Bald
SC
bC
SC
Jind Creek Drainage
Berry Creek Trap Unit
Berry Creek Trap Unit
Forest Peak
Soap Creek Pastures
2.14
2.14
5.3
2.8
5.3
14.3
IC
3.3
2.0
IA
IA
3.14
3.3
1.6
2.3
5.5
SC
SC
SC
IC
10
IC
5k-id Creek Unit
Saturday
14.8
IC
Rickreall Mt. Loop
Skid Creek Unit A
ind Creek Drainage
Cedar Creek Burn
iiles
Foot
14.8
SC
SC
SC
C
Bald Mt. Unit A
Bald Mt. Unit B
Skid Creek Unit A
skid Creek Unit B
Rickreall Mt. Loop
Spot.
IA
IA
Yew Creek Unit A
Soap Creek Burn
Oak Creek Drainage
Creek Burn
Mt. Unit A
Mt. Unit B
Mt. Unit C
Foot
5.5
1.0
2.3
2.6
CC
50
14.6
IC
IC
SC
SC
SC
Totals
SA Spotlighted alternately, early then late
SC Spotlighted at consistent time each night
IA
a1ked alternately, morning then evening
IC Walked conitent1y morning or evening
2.6
2.2
2.2
6.8
2.6
614.3
314.7
M'F:WDIA B
Descriptions of Seven Lamps Tested
on a Sjotliit 1ane
n
Lamp
flumber
Service
Watts
Maximuu
Candle sower
Kor.Vert.
Filament
Shield
Price
ach
1+o05
Automotive
12.8
30
100
45,000
3)4
5
1+1+35
Automotive
12.8
30
100
75,000
5
5
Yea
1+5i
Automotive
6.1+
30
100
55,000
5)4
4)4
Yes
2.60
4516
Automotive
6.2
30
100
4O,QOQ
9
4
Lo
2.50
4522
Aircraft
13.0
250
25
290,000
12
10
Yes
7.10
L535
Automotive
6.1+
30
100
95,000
1+
Yea
2.85
coin
Machines
*
Volts
kite
Hours
At 11+ volts
Amperes
25
.20**
-
5)4
-
3.50
-
50
APPENDIX C
HORIZONTAL BEAM SPREAD MEASUREMENTS FOR SEVEN
LAMPS TAKEN AT TWENTY FIVE YARDS.
26
24
22
20
18
I6
U,
w
-J
z
4
I4
0
0
0
I2
Li
8
6
4
2
0
5
4
3
2
I
0
FEET
I
2
3
4
5
APPENDIX C
(CONTINUED)
36
34
GENERAL ELECTRIC
LAMP NUMBERS:
32
-4522
30
4515
4516
-"--I484
28
26
24
C) 22
-j
Z 20
0
18-
00
Li
16 -
14-
2
I0
6
8
4
/ .f 7
2
/
\\
"
L
0
6
4
3
2
I
FEET
3
4
5
6
APPENDIX 1)
A Summary of Spotlighted Deer Sex and Age
C1assjfjcatjon Obtained between
May and September, 1957
.1
Q
Spotlight Routes
o
Green Peak Unit A
Green Peak Unit 3
Yew Creek Unit A
Yew Creek Unit 3
Soap Creek Burn
Oak Creek Drainage
Bald Mt. Unit A
Bald Mt. Unit B
69
96
205
166
316
102
kO
BaldMt.UnitC
Skid Creek Unit A
Skid Creek Unit B
Rickreall Mt. Loop
Wind Creek
Cedar Creek
Berry Creek Trap
Forest Peak
Soap Creek Pastures
Total Deer
Lf7
38
93
442
167
41
12
15
50
38
k9
13
23
12
5
143
44
47
79
5
20
60
20
25
3
19
28
2152
397
H
4.-t
4)
2
16
10
2
11
12
5
6
96
163
291
239
k32
150
153
-
1
2
9
34
6
16
2
12
3
So
52
141
595
211
220
92
112
121
110
148
3233
1
6
2
5
9
23
17
13
20
3
7
7
15
22
k2
12
6
13
5
6
9
1
2
12
5
4
19
10
1?
16
18
3
9
39
1].
17
13
22
1
1
8
8
2
8
15
11
2
2
299
127
1k
-
Ak-i
DIX E
Summary of Night Deer otivity Observed
While Spotlighting between May and £eptember, 1957
----
-
No.
No.
Spotlight Routes
Standing
Bedded
Green Peak Unit A
Green Peak Unit B
Yew Creek Unit A
Yew Creek Unit B
Soap Creek Burn
Oak Creek Drainage
Bald Mt. Unit A
Bald Mt. Unit B
Bald Mt. Unit C
Skid creek Unit A
Skid Creek Unit B
Rickreall Mt. Loop
hind Creek Drainage
Cedar Creek Burn
Berry Creek Trapping
Forest Peak
Soap Creek Pastures
37
80
14
17
43
27
Total Deer
1.17
Unclassified
47
68
128
Total
Deer
98
165
288
232
450
145
156
82
54
194
67
19
17
4
16
2
16
62
11
8].
31
126
244
16
60
23
19
6
68
335
131
113
51
76
80
14
23
11
74
110
121
1390
365
1464
3219
79
158
110
79
55
46
26
48
9
1
138
591
O9
225
PP2. Dlx F
Atmospheric Conditions Present While Spotlighting
Routes between May and September, 1957
Spotlight Routes
Green Peak Unit A
Green Peak Unit B
Yew Creek Unit A
Yew Creek Unit B
Soap Creek Burn
Oak Creek Drainage
BaldMt.UnitA
Bald Mt. Unit B
Bald Mt. Unit C
Skid Creek Unit A
Skid Creek Unit B
Rickreall Mt. Loop
Wind Creek Drainage
Cedar Creek Burn
Berry Creek Trap Unit
Forest Peak
Soap Creek Pastures
Clear
1k
13
13
7
1k
13
1k
12
12
13
13
12
12
10
13
12
13
*Scattered
Clouds
**Partly
Cloudy
1
1
1
1
1
2
1
1
1
1
1
1
2
2
1
3
1
1
C1oudy
2(1IR)
5
3
2(IIR)
3(I1R)
k
5
IC1IR)
1(1IR)
2
2
Raining
2
1
2
2
6
1
1
14(IIR)
1
3
1
2
2
Foggy
APPENDIX G
A Moving Aver.0 na1ysis o± Lunar f1ects
upon iight Spot1iht Counts
Mean Route Counts by Lunar ;egments
Routes
Green Peak A
Green Peak B
Yew Creek A
Yew Creek B
Soap Creek Burn
Oak Creek
Bald Mt.
Bald Mt. B
Bald Mt. C
Skid Creek A
bkid Creek B
Rickreall
Wind Creek
Cedar Creek
Berry Creek Trap
Forest Peak
Soap Creek Pasture
Sums
Lunar Days
1-15
4-18
7-21
10_21+
13-27
16-30
19-3
22-6
25-9
5.3
8.5
15.4
21.0
21.4
9.6
8.1
3.8
4.8
2.6
8.3
29.2
ii.8
12.1
6.0
7.9
7.1
5.9
9.1
16.6
19.5
23.3
8.9
8.4
,.8
3.5
3.0
9.5
33.5
11.3
14.1
5.1
8.1
7.1
5.7
8.9
5.3
9.4
15.7
20.3
26.6
8.5
8.9
5.2
5.7
3.6
9.6
36.3
5.8
9.9
15.4
20.9
27.5
6.8
9.0
5.7
5.6
4.0
4.7
10.0
14.5
20.9
25.5
7.1
7.7
5.4
5.1
1f.3
4.9
8.7
13.9
21.8
19.3
7.5
6.7
4.7
4.4
3.1
10.1
32.2
11.4
14.9
9.3
13.0
21.3
21.3
8.5
8.0
5.4
4.9
3.0
7.5
23.6
9.9
14.1
7.1
6.4
8.6
182.9
190.7
176.2
16.4
20.3
25.9
7.8
7.8
4.2
5.2
3.8
10.0
35.8
11.1
14.2
5.3
8.4
7.6
198.4
U.S
15.7
4.9
8.8
8.
ok.5
4.6
9.4
30.2
9.5
15.8
6.3
8.0
7.6
7.1
8.9
4.0
8.2
13.2
21.3
23.4
7.3
7.3
5.6
6.8
3.8
8.1
25.9
9.9
14.3
7.0
6.9
8.9
199.4
192.2
181.9
4.].
8.0
23.1
9.4
12.4
7.6
6.0
7.6
169.1
28-12
4.5
8.4
14.3
41.0
18.3
10.0
6.8
4.0
4.3
2.6
7.1
46.7
9.3
13.3
7.9
6.9
8.6
174.0
AFkFNDIX H
A Summary of Deer Sex and Age Classifications
Obtained from loot Ioutes between May and September
'4
195?
M
kLQ
p
i
Foot Routes
u
Groan Peak Unit A
Green Peak Unit B
Yew Creek Unit A
Soap Creek Burn
Bald Mt. Unit A
Bald Mt. Unit B
Skid. Creek Unit A
Skid. Creek Unit B
29
U
83
177
28
21
5
18
Rickreall Loop Road
iad Creek Drainage
Berry Creek Trap Unit
2k9
118
13
Total Deer
752
8
10
19
66
29
10
18
U
k6
90
52
13
52
kk
36
18
26
89
k2
-
8
231
k36
12
7
ko
72
22
7
7
11
52
16
250
9
5
17
1k
10
15
k
8
37
10
10
10
31
75
33
28
6
7
66
38
2
183
310
58
90
236
538
17k
117
£30
83
5k5
268
37
2182
P
tipheic C iJ:ita
t
} lie Conut:tng
v..rinF fcot Mtte Gounts
ay and Lejte ber i937
Liy Morning anit
bet-een
**]
foot Routes
Clear
Claude
Cloudy
Green Peak Unit A
Green Peak Unit B
8
8
1
2
Yw Creek Unit A
8
k
2
3
1
1
Coa Creek Burn
&J.d Mt. Unit A
Bald Mt. Unit B
k±d Creek Unit A
Skid Creek Unit B
Rickreall Mt. Loop
wind Creek Drainage
Berry Creek Trap Unit
10
9
11
7
7
8
6
8
Totals
Per Cent of Total
90
*
***
10-25 per cent cloud cover
26-70 per cent cloud cover
71-100 per cent aloud cover
Lf5
3
i
1
1
***C].c)1y
Raining
6
Foggy
1
7
2
1
2
1
2
3.
6
9
3.
1
5
5
k
5
5
2
1
3
3
2
1
2
2
1
12
6
U
22
58
29
5
2
1
9
7