Shuswap and Boundary Mule Deer Composition Surveys:
December 2010
Aaron Reid
Ministry of Forests, Lands and Natural Resource Operations
Fish & Wildlife Section
Penticton, BC
February 2011
Funding provided by the Habitat Conservation Trust Foundation
Executive Summary
In 2010, Region 8 applied the new Southern Interior Mule Deer Harvest Strategy to: align
hunting seasons with adjacent Regions, simplify hunting regulations, and increase mule deer
hunting opportunity in the Okanagan Region. Harvest statistics suggest that mule deer are
recovering from a population decline in the mid 1990s; however, this recovery has not been
uniform across the Region. Hunter harvest and success in MUs 8-13, 15, 24, and 25 have lagged
behind the rest of Region 8.
Currently, information on sex ratios of mule deer populations is limited and managers are
uncertain how current hunting season changes will affect population composition and population
growth, as well as hunter success and satisfaction. The objective of this project is to collect buck
ratio data from the Shuswap and Boundary areas where population numbers are felt to be in
recovery and may be more vulnerable to the new hunting season changes.
A sample of 384 mule deer were counted and classified in MU 8-23. I calculated the total buck
to doe ratio for MU 8-23 as 22 bucks: 100 does ([CI 90%] 18-26), 15 < 4pt bucks: 100 does (CI
11-20) and 7 > 4pt bucks: 100 does (CI 4-10). A sample of 157 mule deer in MU 8-14 was
counted and classified during the survey. I calculated the total buck to doe ratio for MU 8-14 at
31 bucks: 100 does ([CI 90%] 22-42), 19 < 4pt bucks: 100 does (CI 12-29) and 12 > 4pt bucks:
100 does (CI 6-21). A sample size of 147 mule deer in MU 8-15 was counted and classified
during the survey. I calculated the total buck to doe ratio for MU 8-15 at 16 bucks: 100 does ([CI
90%] 10-25), 10 < 4pt bucks: 100 does (CI 5-17) and 7 > 4pt bucks: 100 does (CI 3-14).
Mule deer ranged between 580 m and 1660 m elevation during the surveys. Bucks, > 4pt and <
4pt, were observed throughout this elevation range. However, on average bucks were observed at
slightly higher elevation than does (P = .0002). There was no significant difference between
oblique crown closure estimates for bucks 30% (90% CI 24-36) or does 26.7% (CI 23-30) during
the survey (P = 0.2).
All buck ratios were above the desired harvest strategy target of 20 bucks: 100 does with the
exception of MU 8-15. Confidence intervals from this survey overlap with previous composition
surveys from MUs 8-15 and 8-23 and suggest there was no change in buck ratios between survey
years in these units.
To minimize any potential difference in sightability between bucks and does, we attempted to
complete the surveys early in December before bucks disperse into bachelor groups. Our
distribution data supported this strategy and we recommend completing mule deer compositions
surveys in November or by early December at the latest. This report presents data from year one
of a two year Habitat Conservation Trust Foundation funded project.
2
Contents
List of Tables .................................................................................................................................. 4
List of Figures ................................................................................................................................. 4
List of Appendixes .......................................................................................................................... 5
Introduction ..................................................................................................................................... 6
Study Areas ..................................................................................................................................... 8
Shuswap MU 823 ........................................................................................................................ 8
Boundary MU 812,814,815......................................................................................................... 9
Methods......................................................................................................................................... 10
Survey Area Selection ............................................................................................................... 10
Survey Procedures ..................................................................................................................... 11
Classification ............................................................................................................................. 11
Data Analysis ............................................................................................................................ 11
Ground Surveys ......................................................................................................................... 12
Results ........................................................................................................................................... 12
Shuswap .................................................................................................................................... 12
Boundary ................................................................................................................................... 14
Elevation Distribution ............................................................................................................... 19
Other Species............................................................................................................................. 20
Discussion ..................................................................................................................................... 21
Distribution................................................................................................................................ 21
Buck ratios................................................................................................................................. 22
Shuswap MU 8-23 ................................................................................................................. 22
Boundary MU 8-12, 8-14, 8-15 ............................................................................................. 23
Survey Methods......................................................................................................................... 25
Recommendations ......................................................................................................................... 26
Methods ..................................................................................................................................... 26
Management .............................................................................................................................. 26
Acknowledgements ....................................................................................................................... 27
3
Literature Cited ............................................................................................................................. 27
Appendix 1 .................................................................................................................................... 29
List of Tables
Table 1: Classification of mule deer observed during the aerial composition survey in MU 8-23
on December 2nd and 3rd, 2010. .................................................................................................... 13
Table 2: The encounter rate (deer/hr) of mule deer during aerial composition surveys in MU 8-23
on December 2nd and 3rd, 2010. ..................................................................................................... 14
Table 3: Classification of mule deer observed during the aerial composition survey in MU 8-12
and 8-14 on December 10th, 11th and 15th, 2010............................................................................ 15
Table 4: Classification of mule deer observed during the aerial composition survey in MU 8-15
on December 11th and 15th, 2010. .................................................................................................. 16
Table 5: The encounter rate (deer/hr) of mule deer during aerial composition survey in MU 8-14
and 8-15 on December 10th, 11th and 15th, 2010............................................................................ 17
Table 6: Summary of species observed during aerial surveys in MU 8-14,15,23 in December,
2010............................................................................................................................................... 21
Table 7: The percent of bucks observed with at least one doe during composition surveys across
the Okanagan and Kootenay Regions in 2010. ............................................................................. 22
List of Figures
Figure 1: Mule deer harvest in MU 8-23 compared to 8-13, 24 and 25 (combined) in Region 8
from 1990 to 2008. .......................................................................................................................... 6
Figure 2: Region 8 and MU 8-15 hunter days / kill and mule deer harvest for MU 8-15 from
1990 to 2008. .................................................................................................................................. 7
Figure 3: Map showing areas surveyed for mule deer during composition surveys, December
2010............................................................................................................................................... 10
Figure 4: Map showing ungulate observations scaled to group size during the Shuswap survey
December, 2010. ........................................................................................................................... 13
Figure 5: Map showing flight path for the mule deer composition survey in the Shuswap
December, 2010. ........................................................................................................................... 14
Figure 6: Map of ungulate observations scaled to group size for the west Boundary survey
December, 2010. ........................................................................................................................... 16
Figure 7: Map of ungulate observations scaled to group size for the east Boundary survey
December, 2010. ........................................................................................................................... 17
Figure 8: Map showing flight path for the mule deer composition survey in the west Boundary
December, 2010. ........................................................................................................................... 18
4
Figure 9: Map showing flight path for the mule deer composition survey in the east Boundary
December, 2010. ........................................................................................................................... 19
Figure 10: Elevation of mule deer observed in MU 8-23, 8-12, 8-14 and 8-15 from composition
surveys December 2010. Elevation was determined by joining GPS waypoints observations to
the closest 20 m contour in ArcGIS. ............................................................................................. 20
Figure 11: Bucks / 100 does (buck to doe ratio) with 90% confidence intervals for January 2010
and December 2010 MU 8-23....................................................................................................... 23
Figure 12: Bucks / 100 does (buck to doe ratio) with 90% confidence intervals for 2000, 2002,
2008 and 2010 in MU 8-15. All but the 2010 data were surveyed in January; antler drop may
bias the buck ratio lower. .............................................................................................................. 24
Figure 13: Hunter kill and harvest in MU 8-15 from 1987 to 2008. ............................................ 24
List of Appendixes
Appendix 1: Kill data from Region 8 from the 1990s "good years" and 2000s. The table
compares the 5 year average kill (2003-2007) as a percentage of “good years” (1990-1996). .... 29
5
Introduction
In 2010, Region 8 applied the new Southern Interior Mule Deer Harvest Strategy (MOE Mule
Deer Harvest Strategy, 2010) to: align hunting seasons with adjacent Regions, simplify hunting
regulations, and increase mule deer hunting opportunity in the Okanagan Region. The most
significant change of the new harvest strategy was an increase to the “any buck” season through
the month of October across all Management Units (MU). This change increased the “any buck”
season by 10 days from previous years.
Mule deer populations in the Southern Interior peaked in the mid 1950s and we have not seen
populations as high since (Hatter et al. 1998). The latest peak in mule deer numbers in the
Okanagan occurred in the early 1990s but by 1998 mule deer numbers had declined by as much
as 50% since the peak in 1992 (Harper 1998). Harvest statistics suggest that mule deer are
recovering from the population declines of the mid 1990s; however, this recovery has not been
uniform across the Region. Hunter harvest and success in MUs 8-13, 15, 24, and 25 have lagged
behind the rest of Region 8 (Appendix 1).
In the Shuswap drainage, MU 8-23 supports the majority of harvest compared to neighbouring
MUs 8-13, 24, and 25 (Figure 1). However, for several years now anecdotal reports from local
hunters and the guide outfitter have expressed concerns that mule deer numbers are down in MU
8-23.
823
813, 24, 25 Combined
400
350
Harvest
300
250
200
150
100
50
0
Figure 1: Mule deer harvest in MU 8-23 compared to 8-13, 24 and 25 (combined) in Region 8 from
1990 to 2008.
6
Hunter harvest and success rates have improved in the Boundary, since the mule deer population
decline in the mid 1990s, and are close to the regional average with the exception of MU 8-15,
which has been slower to recover (Figure 2). Local resident hunters and guide outfitters have
expressed concerns for several years now about low mule deer numbers and reduced harvest in
MU 8-15 compared to the 1990s (Figure 2).
400
350
300
250
200
150
100
50
0
8-15 Days / Kill
Region Days / Kill
80
70
60
50
40
30
20
10
0
Hunter Days / Kill
Harvest
8-15 Harvest
Figure 2: Region 8 and MU 8-15 hunter days / kill and mule deer harvest for MU 8-15 from 1990 to
2008.
Aerial surveys for mule deer in the Shuswap and Boundary have been limited. In the Boundary
mule deer data is only available for MU 8-15: composition surveys in 2000, 2002, and 2008
found 12 ([CI 90%] 7-19), 15 (CI 8-24), and 13 (CI 8-20) bucks per 100 does, respectively. In
the Shuswap, a small portion of MU 8-23 was surveyed in January 2010. Ratios from that survey
were 24 (CI 17-31) bucks: 100 does. However, the 2008 (8-15) and 2010 (8-23) surveys were
completed in January when antler drop may have started as well as winter separation of bucks
and does, both of which may negatively bias composition data.
Currently, information on sex ratios of mule deer populations is limited and managers are
uncertain how current hunting season changes will affect population composition and population
growth, as well as hunter success and satisfaction. Maintaining ratios of 20 bucks to 100 does
post-hunt is recommended to ensure the breeding success and a diversity of hunting opportunties
of hunted mule deer populations (MOE Mule Deer Harvest Strategy, 2010). Recent changes in
mule deer seasons will require reliable composition data to assess the effects of the hunting
regimes on mule deer demographics.
Some Resident hunters and guide outfitters have expressed concerns that the new hunting
regulations will reduce already low mule deer populations and buck numbers in the MUs
discussed above. The objective of this project is to collect buck ratio data from the Shuswap and
Boundary areas where it is felt that new hunting regulations may have the greatest impact on
7
mule deer populations. This report presents data from year one of a two year Habitat
Conservation Trust Foundation funded project.
Study Areas
Shuswap MU 823
We focused our surveys on winter ranges near Lumby and Cherryville north of Highway 6
(Figure 1). The Shuswap winter ranges occur primarily in a dry climatic zones but parts do
extend into a moist climatic region at higher elevation. Lower elevations, between 500 and 1300
m, are in the Interior Douglas-fir (IDF) biogeoclimatic zone (BEC), the Kettle Dry Mild (dm1),
and Shuswap Moist Warm (mw1) subzones/variants. The ICHdm1 near Montgomery is slightly
drier than the ICHmw1 to the east. Both zones support climax stands of Douglas-fir
(Pseudostsuga menziesii), ponderosa pine (Pinus ponderosa) and a dominant understory of
bluebunch wheatgrass (Agropyron spicatum) (dm1), Saskatoon (Amelanchier alnifolia), falesbox
(Paxistima myrsinites, and bluebunch wheatgrass (mw1) on dry winter ranges.
Mid-slope winter range, between 1100 -1500 m, occurred in the Interior Cedar-Hemlock (ICH)
zone, Kootenay Moist Cool (mk1) and Thompson Moist Cool (mk2) subzones/variants. In
summer the ICHmk1 is slightly warmer and drier than the mk2. On dry sites both support stands
of Douglas-fir and lodgepole pine (Pinus contorta); western larch (Larix occidentialis) only
occurs in the mk1. Juniper (Juniperus communis) and pinegrass (Calamagrostis rubescens) are
common understory plants in each variant.
At higher elevations, 1450-1650 m, the study area reaches into the Engelmann Spruce-Subalpine
Fir (ESSF) zone, Columbia Wet Cold (wc1) subzone/variant. These forests are typically colder,
wetter and receive more snow than the ICH. Typical vegetation includes climax stands of
subalpine fur (Abies lasiocarpa), Engelmann spruce (Picea engelmannii) and understory of
western redcedar (Thuja plicata), hemlock (Tsuga heterophylla), black huckleberry (Vaccinium
membranaceum) and white-flowered rhododendron (Rhododendron albiflorum).
A mixture of open forest, shrub dominated slopes, and deciduous forests are common on lower
elevation winter ranges in the Shuswap. Higher elevation areas are typically closed canopy
forests with logging as the primary disturbance type. The Shuswap winter ranges receive more
moisture than the Boundary and have greater vegetative cover, especially at lower elevations.
The 29 year average annual precipitation for Lumby is 628 mm vs 509 for Grand Forks
(Environment Canada Climate Data).
8
Boundary MU 812,814,815
We surveyed the Boundary winter ranges from Rock Creek to Christina Lake on the north side of
Highway 3 (Figure 1). The Boundary winter ranges occur primarily in a dry climatic region. Low
elevations, between 500-950 m, are in the Ponderosa Pine (PP) zone, Kettle Dry Hot (dh1)
subzone/variant. The climate is characterized by very hot, dry summers, and mild winters with
little snow fall. Vegetation is dominated by open ponderosa pine forests and grasslands.
Mid-elevation winter ranges, up to 1370 m, are within the IDF zone, Kettle Dry Mild (dm1)
subzone/variant. Typical climate conditions for the IDFdm1 are hot, dry summers and cool
winters with light snowfall. Closed canopy Douglas-fir forests are common with moderate shrub
cover and a pinegrass dominated understory.
In west Boundary, Midway to Rock Creek, upper elevation winter ranges, greater than 1400 m,
occur within the Montane Spruce (MS) zone, Okanagan Dry Mild (dm1) subzone/variant. In the
east Boundary, Grand Forks to Christina Lake, upper elevations occur within the ICH zone,
Columbia Moist Warm (mw2) subzone/variant. The MSdm1 has warm, dry summers, and cold
winter with light snowfall and light snowpacks, whereas the ICHmw2 has hot, moist summers,
and mild winters with light snowfall and moderate snowpacks. Mixed seral species such as
Douglas-fir, lodgepole pine, and western larch are found throughout both zones but climax
species in the MS are white spruce subalpine fur, whereas the climax species in the ICH are
western redcedar and western hemlock (Tsuga hererophylla).
Lower elevations winter ranges in the Boundary are dominated by open grassland habitats with
infrequent patches of thicker vegetation in areas that maintain moisture (e.g. gullies). Mid-to
high elevation transition into close forest conditions quickly. Most open habitats at high
elevation are created from logging disturbance.
9
Figure 3: Map showing areas surveyed for mule deer during composition surveys, December 2010.
Methods
Survey Area Selection
Survey units or “blocks” were created from analysis of provincial mule deer winter range
mapping, previous winter mule deer aerial survey observations, and interviews with local hunters
and guide outfitters. Block boundaries ranged from rivers and roads in the valley bottom up to
1700 m elevation with a focus on solar aspects. Blocks were intended to include the entire mule
deer sub-population.
10
Survey Procedures
General survey standards were adopted from aerial-based inventory techniques for selected
ungulates (RISC, 2002). Surveys were conducted with a Bell 206 Jet Ranger equipped with rear
bubble observation windows. Encounter transects were used to locate mule deer with transects
spaced at approximately 400 m in open habitats and 200 m in more closed forested habitats.
Transects typically followed contours from either low elevation to high or vice versa. Speeds of
50-80 km/hour were targeted while maintaining a distance of 20-100 m above the tree tops.
We used three people on survey at all time: one navigator in the front seat and two observers in
the rear. The navigator used the track log function and real time navigation feature on a Garmin
60Cx handheld GPS to maintain transect width, monitor survey coverage, and mark waypoints of
animal locations. The navigator also recorded data and took pictures of larger doe/fawn groups
and bucks whenever possible. The observer’s main task was to spot animals and classify age and
sex. Generally, the observed animals would be put on the navigator’s side of the helicopter to be
counted, classified, and photographed. Each group of animals was circled and in areas with high
crown closure, deer were sometimes herded into openings until classification was possible. In
cases where mule deer were lost in high crown closure forests, they would be recorded as
“unclassified”. We surveyed to the height of land in each block or, to the elevation where deer
tracks were no longer present in the snow.
Classification
Prior to the survey period a discussion was held between the Provincial Ungulate Specialist
Gerry Kuzyk and all Regions taking part in post-hunt mule deer composition surveys for winter
2010/2011. One objective of the discussion was to standardize buck classification between
Regions. The consensus was to use a two category, < 4pt and > 4pt buck classification scheme
based on definitions of 4 point in the British Columbia Hunting and Trapping Synopsis
(http://www.env.gov.bc.ca/fw/wildlife/hunting/regulations/). The 4pt buck definition reads: any
buck having at least four tines, excluding brow tine, on one antler. Antlerless deer were classified
as adult female (less than 1.5 years old) and fawns (young of the year). We completed the survey
is early to mid-December to ensure bucks were classified before antler drop which is known to
begin in early January (Stent Personal Com. 2010 and Harris 2010b).
Data Analysis
Originally we proposed running the composition data through Hiller 12-e mule deer model to
correct for incomplete sightability (Unsworth et al., 1998). This model was developed in Idaho
to correct for expected number of animals missed during aerial survey. However, results from
11
Kootenay mule deer survey analysis in 2009/2010 questioned the suitability of the Idaho model
in BC habitats (Stent, 2010). Therefore, the Idaho Sightability model was not used to analyse
our survey data. We calculated confidence intervals (90%) using the binomial variance estimator
in the programs distributed with Ecological Methodology (Krebs 1999).
Ground Surveys
Ground surveys were originally proposed as part of the survey methodology to supplement
helicopter data and evaluate the feasibility of alternative survey methods. Results from the
Kootenay surveys in 2009/2010 recommended against using this method to collect composition
data for mule deer in their Region (Stent, 2010). Poor visibility due to high vegetative cover on
winter ranges prevented the collection of sufficient sample sizes. We assessed our winter ranges
from this perspective and concluded that lack of vantage points and high vegetative cover was
also a factor on most of the primary winter ranges. Ground surveys were consequently removed
as a method for this project.
Results
Shuswap
Two survey days, December 2nd and 3rd, were completed before the weather turned unfavourable
for flying. South Fork, Currie Creek and Cherry Ridge were surveyed on December 2nd; Byers
Range and Montgomery were surveyed on December 3rd. Snow pillow data from the two closest
stations, Barnes Creek (1595 m) and Park Mountain (1857 m), recorded high elevation snow
packs of approximately 64% of the 22 year average for early December, 2010. Survey conditions
were generally fair but the occasional mid-elevation and low valley fog were encountered. There
was several cm of fresh snowfall overnight at higher elevations for each survey date.
A sample size of 384 mule deer were counted and classified in MU 8-23 (Table 1, Figure 2). I
calculated the total buck to doe ratio for MU 8-23 at 22 bucks: 100 does ([CI 90%] 18-26), 15 <
4pt bucks: 100 does (CI 11-20) and 7 > 4pt bucks: 100 does (CI 4-10). I calculated 69 fawns:
100 does (CI 65-72) in MU 8-23.
12
Table 1: Classification of mule deer observed during the aerial composition survey in MU 8-23 on
December 2nd and 3rd, 2010.
MU 8-23
South Fork &
Currie Creek
Cherry Ridge
Byers Ridge
Montgomery
Total
Fawns
Does
Unclassified
<4pt Bucks
>4pt Bucks
All Bucks
Total
19
27
1
9
3
12
59
3
75
36
133
10
111
46
194
3
6
5
15
1
15
4
29
1
9
0
13
2
24
4
42
18
215
92
384
Figure 4: Map showing ungulate observations scaled to group size during the Shuswap survey
December, 2010.
A total of 7.95 hrs of survey time was spent on the Shuswap winter ranges (Figure 3). Using
deer/hr as a measure of activity Montgomery was the busiest winter range followed by Byers
Range, South Fork and Currie Creek, and finally, Cherry Ridge (Table 2).
13
Table 2: The encounter rate (deer/hr) of mule deer during aerial composition surveys in MU 8-23
on December 2nd and 3rd, 2010.
Winter Range
South Fork & Currie Creek
Cherry Ridge
Byers Range
Montgomery
Time on Survey (hr)
2.3 hr
1.1 hr
3.7 hr
0.8 hr
Encounter Rate (deer/hr)
25
16
57
112
Figure 5: Map showing flight path for the mule deer composition survey in the Shuswap December,
2010.
Boundary
Three survey days, December 10th, 11th and 15th, were completed across MU 8-12, 8-14, and 815. Winter ranges surveyed included: Johnstone Creek (8-12), Ingram Creek (8-14), Toronto to
Lynch Creek (8-15) and Sand to Spooner Creek (8-15). Snow pillow data from Grano Creek
(1874 m), the closest station to the survey area, recorded high elevation snow packs of
approximately 87% of the 12 year average for December 10th, 2010. Survey conditions were
14
poor for the MU 8-12 portion of the survey; low ceiling cloud prevented us from surveying
above 1120 m elevation. Conditions were good for MU 8-14; we were able to survey from the
height of land to valley bottom. Cloud cover at high elevations forced us to break MU 8-15 into
two survey days. All low elevation (below 800 m) south facing blocks were snow free during
the surveys.
A sample size of 157 mule deer in MU 8-14 was counted and classified during the survey (Table
3, Figure 4). I didn’t include composition data analysis for MU 8-12, since the entire elevation
range was not surveyed. I calculated the total buck to doe ratio for MU 8-14 at 31 bucks: 100
does ([CI 90%] 22-42), 19 < 4pt bucks: 100 does (CI 12-29) and 12 > 4pt bucks: 100 does (CI 621). I calculated 87 fawns: 100 does (CI 78-93) in MU 8-14.
Table 3: Classification of mule deer observed during the aerial composition survey in MU 8-12 and
8-14 on December 10th, 11th and 15th, 2010.
MU 8-12 & 8-14
Johnstone Ck1
Ingram Ck
Total
1
Fawns
30
58
88
Does
47
67
114
Unclassified
2
7
9
<4pt Bucks
0
13
13
>4pt Bucks
0
8
8
All Bucks
0
21
21
Total
86
157
243
A low cloud ceiling prevented us from surveying above 1120m elevation
15
Figure 6: Map of ungulate observations scaled to group size for the west Boundary survey
December, 2010.
A sample size of 147 mule deer in MU 8-15 was counted and classified during the survey
(Figure 5, Table 4). I calculated the total buck to doe ratio for MU 8-15 at 16 bucks: 100 does
([CI 90%] 10-25), 10 < 4pt bucks: 100 does (CI 5-17) and 7 > 4pt bucks: 100 does (CI 3-14). I
calculated 66 fawns; 100 does (CI 56-75) in MU 8-15.
Table 4: Classification of mule deer observed during the aerial composition survey in MU 8-15 on
December 11th and 15th, 2010.
MU 8-15
Toronto to Lynch Ck
Sand to Spooner Ck
Total
Fawns
10
38
48
Does
8
65
73
Unclassified
4
8
12
<4pt Bucks
3
4
7
>4pt Bucks
4
1
5
All Bucks
7
5
12
Total
29
118
147
16
Figure 7: Map of ungulate observations scaled to group size for the east Boundary survey
December, 2010.
A total of 11.1 hrs of survey time was spent on the Boundary winter ranges (Figures 6 and 7).
Using deer/hr as a measure of activity, Ingram Creek was the busiest winter range, followed by
Sand to Spooner, and then Toronto to Lynch (Table 5). We encountered 87 deer/hr at Johnstone
Creek; however, this value was not included in the analysis because the higher elevations were
not surveyed. Higher crown closure forests at high elevations required more search effort.
Table 5: The encounter rate (deer/hr) of mule deer during aerial composition survey in MU 8-14
and 8-15 on December 10th, 11th and 15th, 2010.
Winter Range
Ingram
Toronto to Lynch
Sand to Spooner
Time on Survey (hr)
2.9
2.6
4.7
Encounter Rate (deer/hr)
55
11
25
17
Figure 8: Map showing flight path for the mule deer composition survey in the west Boundary
December, 2010.
18
Figure 9: Map showing flight path for the mule deer composition survey in the east Boundary
December, 2010.
Elevation Distribution
Mule deer ranged between 580 m and 1660 m elevation during the surveys. Bucks, > 4pt and <
4pt, were observed throughout this elevation range (Figure 8). On average bucks were observed
at 156 m higher in elevation than does (P = .0002). There was no significant difference between
oblique crown closure estimates for bucks 30% (90% CI 24 – 36) or does 26.7% (CI 23-30)
during the survey (P = 0.2).
19
Does & Fawns
<4pt
>4pt
0.25
Proportion
0.2
0.15
0.1
0.05
0
Elevation (m)
Figure 10: Elevation of mule deer observed in MU 8-23, 8-12, 8-14 and 8-15 from composition
surveys December 2010. Elevation was determined by joining GPS waypoints observations to the
closest 20 m contour in ArcGIS.
Other Species
Multiple species were observed during the survey including: elk, bighorn sheep, moose, whitetailed deer, cougar, wolf, golden eagle and coyote (Table 6). A total of 199 white-tailed deer
were observed during the survey; they were common on most of the blocks with the exception of
the MU 8-12 and 8-14, were they were observed infrequently. Elk (n=96) were observed in most
MUs with the exception of 8-12. We counted 124 bighorn between Sand and Spooner Creek,
which was similar to the previous aerial survey count of 129 in March, 2010. Aerial surveys are
not complete censuses; animals are always missed during surveys and animals not observed are
usually accounted for by a sightability correction (Caughley et al. 1974, Samuel et al. 1987).
Poole (2010) used collared sheep to derive a sightability of 0.82 for open habitat in the East
Kootenay, if this correction is applied to n=124 our population estimate for bighorn from Sand to
Spooner Creek would be 151 bighorn.
20
Table 6: Summary of species observed during aerial surveys in MU 8-14,15,23 in December, 2010.
Species
Elk
Bighorn Sheep
White-tailed Deer
Moose
MU
8-23
8-14
8-15
Unclassified
30
0
31
Juvenile
0
4
1
Adult Female
0
4
1
Adult Male
8
6
9
Total
40
14
42
8-15
116
0
0
8
124
8-23
8-14
8-15
8-14
8-15
110
3
68
0
0
0
0
0
1
0
0
0
0
2
2
14
1
3
0
0
124
4
71
3
2
Discussion
Distribution
Mule deer observations ranged from 580 m to 1660 m elevation. Even though bucks were
observed at slightly higher elevations than does, bucks were encountered across the entire
elevation range, which was expected because we surveyed during the rut. We conclude that all
bucks in the wintering population were included in our survey area.
Differential sightablity of bucks and does was discussed amongst southern interior mule deer
managers prior to the surveys. Experience in other Regions suggested that mule deer bucks begin
to separate from does and move into bachelor groups after the 10th of December (Pat Dielman
Personal Com.). Currently, there is no research specific to mule deer sightablity available in
British Columbia. To minimize any potential difference in sightablity between bucks and does,
we attempted to complete the surveys early in December before bucks disperse into bachelor
groups. Our survey documented no significant difference in crown closure for buck and doe
observations, suggesting similar sightablity between sexes for this survey period. We believe
buck ratios were not biased by differences in sightability between the sexes.
Our results support the theory of buck dispersal away from does after the 10th of December. We
looked at the percent of bucks observed with at least one doe during composition surveys in the
Okanagan and Kootenay Regions in 2010 (Table 7). The data shows a decrease in the number of
bucks occurring with does over time from November to January, which is to be expected as the
rut comes to an end. The data suggests that bucks and does should have similar sightability until
21
early December. We suggest that mule deer composition surveys be completed before December
5th, preferably in second or third week of November.
Table 7: The percent of bucks observed with at least one doe during composition surveys across the
Okanagan and Kootenay Regions in 2010.
Survey Dates
November 22 & 23rd, 2010
December 2 & 3rd, 2010
December 10, 11 & 15th, 2010
December 15 & 22nd, 2010
January 6th, 2010
MU
4-02,21,22
8-23
8-12, 14, 15
4-03,06,07
8-23
% Bucks with Does
92
79
40
52
35
Sample Size
596
384
390
246
233
Using deer/hr as a measure of activity can be useful but should be interpreted with caution. To
draw direct comparisons, the survey effort for each survey should be the same and each winter
range should be considered independently. Mule deer are not the only species encounter during
survey and when other species, for example bighorn and elk, are present they increase the flight
time and therefore decrease the deer/hr encounter rate. I included this measure to give a general
sense of activity and to identity outliers such as the Granby (i.e. Toronto to Lynch Creek), where
only 11 deer/hr were observed. The Granby is an example where only 26 deer were observed in
nearly 3 hours of survey; the other extreme was Montgomery, in the Shuswap, where we
observed 92 deer in 49 minutes (112 deer/hr).
Buck ratios
A performance measure of the Southern Interior Mule Deer Harvest Procedure (MOE Mule Deer
Harvest Strategy, 2010) is to “provide a variety of hunting opportunities by endeavouring to
maintain a minimum buck:doe ratio of 20 bucks:100 does after the hunting season (post-hunt)
within most Population Management Units”. This measure was the primary objective for our
composition surveys. We observed greater than 20 buck: 100 does in all but one MU.
Shuswap MU 8-23
We calculated a ratio of 22 bucks: 100 does ([CI 90%] 18-26) in MU 8-23 in December. This
ratio is lower than the previous survey of Byers Range and Cherry Ridge in January, 2010, where
ratios were 24 bucks: 100 does (CI 17-31) (Harris, 2010). However, the December confidence
intervals overlap the January ratio suggesting no significant change in buck ratio between years
(Figure 11). Several bucks were observed with only one antler during the January survey. If
antlerless bucks were classified as does, bucks could have been under represented during this
22
survey. The overall sample size was greater in December 2010 (n= 369) than January 2010
(n=195), resulting in a more precise estimate.
Bucks / 100 Does
35
30
25
20
15
10
January 2010
December 2010
Figure 11: Bucks / 100 does (buck to doe ratio) with 90% confidence intervals for January 2010 and
December 2010 MU 8-23.
Boundary MU 8-12, 8-14, 8-15
Composition numbers for mule deer are limited in MU 8-12 and 8-14. We were unable to survey
above 1120 m elevation in 8-12 because of a low cloud ceiling. Since the higher elevations were
not accessible, we did not calculate a buck ratio in MU 8-12. At lower elevation we didn’t
observe any bucks during survey. However, we did encounter 89 mule deer in 0.9 hrs of survey
with 69 fawns: 100 does, which suggests that reproduction is similar in this unit to other survey
units.
A ratio of 31 bucks: 100 does was observed in the Ingram Creek area (MU 8-14). A ratio of 12
>4pt bucks: 100 does and 19 < 4pt bucks:100 does suggests mature and younger bucks are
surviving the “4pt” and “any buck” seasons. MU 8-14 had the highest fawn production with 87
fawns: 100 does. Ingram Creek is only a small portion of the winter ranges in MU 8-14 but since
regulations and access are constant throughout the MU, Ingram Creek should be representative
of the remainder of winter range in the MU.
Previous composition surveys in MU 8-15 in December 2000, 2002, and 2008 found 12 ([CI
90%] 7-19), 15 (CI 8-24), and 13 (CI 8-20) bucks per 100 does, respectively. We documented 16
bucks: 100 does (CI 10-25) which overlaps with previous ratio; therefore, our data suggest no
change in buck ratios in this MU since 2000 (Figure 12). This ratio is low and the data suggests
that it has been low for at least a decade. The Granby winter ranges (i.e. Toronto to Lynch
Creek) were of particular interest since aerial survey information on mule deer was lacking in
this area. We observed only 26 mule deer in 2.6 hrs (11 mule deer/ hr) of survey. This data
23
suggests that the south slope ranges (i.e. Sand to Spooner Creek) are currently supporting the
bulk of the wintering mule deer in MU 8-15.
30
Bucks / 100 Does
25
20
15
10
5
0
2000
2002
2008
2010
Figure 12: Bucks / 100 does (buck to doe ratio) with 90% confidence intervals for 2000, 2002, 2008
and 2010 in MU 8-15. All but the 2010 data were surveyed in January; antler drop may bias the
buck ratio lower.
Our survey data supports local residents and guide outfitters’ concerns of depressed mule deer
numbers and buck ratios in this MU since the early 1990’s. Hunter numbers and harvest of mule
deer in MU 8-15 has declined since a peak in 1992 (Figure 13) but over the last decade harvest
has remained stable and hunter success has modestly improved (Figure 2).
MU 8-15 Hunter Numbers
MU 8-15 Hunter Kills
1200
350
300
800
600
400
250
200
150
Hunter Kill
Hunter Numbers
1000
400
100
200
0
50
0
Figure 13: Hunter kill and harvest in MU 8-15 from 1987 to 2008.
24
The population decline in the 1990s was exacerbated by a hard winter in 1996/97 in which many
deer died (Harris 2010). Hunting regulations were tightened in 1998 to allow recovery. Doe
authorizations were reduced to 5 annually, making the doe harvest negligible. Buck ratios are
below the provincial target but literature suggests that buck ratio is unrelated to the fawn
recruitment the following year (Erickson et al. 2003); all does get bred except at very low buck
ratios. Therefore, buck harvest is unlikely to be limiting population recovery. Limiting hunter
numbers could reduce harvest and increase buck ratios but this measure is not likely to influence
population growth because there are many other factors influencing mule deer population
growth.
Potential limiting factors on mule deer population growth in the area include intrespecific
competition on winter ranges and habitat issues. Interspecific species competition on winter
ranges with wild and domestic ungulates include:
 Elk transplanted in the 1970s, near Christina Lake, have increased to approximately 50 elk in
the eastern half of the winter range;
 Bighorn transplanted in the 1980s have reached numbers > 120 head;
 Recent spring carry over counts observed several hundred whitetail deer; and
 Cattle graze the winter range into December.
Grazing pressure is high on the primary winter range in 8-15 (i.e. Sand to Moody Creek);
however, range conditions in the area are improving within recent years according to Werner
Baliko, Ministry Range Specialist (Personal Communication 2011). Changes in the natural fire
regime have also influenced mule deer populations in the area. Decades of fire suppression, has
resulted in the loss of large scale landscape disturbances and allowed forest ingrowth into
grasslands. In addition, many locals have expressed concerns that north-south migration may
have been impacted by the installation of wildlife fencing along Highway 3 in the late 1980s.
Survey Methods
To ensure population ratios were representative for each MU we focused on achieving a large
sample size and covering all potentially occupied habitat for each survey block. The survey
budget was sufficient to accomplish both factors. Our distribution data supports the importance
of accessing high elevation winter range for mule deer to ensure bucks are equally
representative, especially when survey dates extend past the first week of December.
We found that use of photographs increased our ability to classify mature bucks. Post-survey
photograph analysis resulted in 11 errors in our in buck classifications. Eight times we classified
bucks during survey as <4pt when photo analysis confirmed that the bucks were > 4pt. On three
occasions we classified bucks > 4pt when photos latter confirmed they where < 4pt bucks. We
25
used experienced observers during the fights including regional biologists, conservation officers
and guide outfitters; therefore, I am confident that errors were not a result of inexperience but
rather emphasize the challenges of classifying mule deer bucks in high crown closure forests. No
errors were detected in the few doe/fawn photographs taken. Although we did not photograph as
many doe/fawn groups as we would have liked, we do recommend doing so whenever possible.
This technique is useful for both verifying classification post-survey and calibrating fawn
classifications with observer’s pre-survey.
Recommendations
Methods




Photographs should be taken at high resolution, fast shutter speeds and in drive mode so
multiple photographs per second are captured. Stent (2010) recommended photographing
profiles of bucks to maximize visibility of antler branches and tines. Photos of bucks looking
at the camera and running directly away should be avoided. Profile pictures of does and
fawns are also recommended for comparing rostrum lengths.
Continue photographing all bucks > 2 pt. Ensure classification from the helicopter is
completed since photographs are not always reliable (e.g. out of focus, poor angle, obscured
by vegetation).
Photograph large doe and fawn groups when possible to verify fawn classification.
Survey should be conducted in late November or early December, providing snow levels are
sufficient to move deer onto the winter range.
Management


Based on observations from the air, winter ranges from Toronto Creek North (e.g. Millar
Creek) have potential for highly suitable winter range, but conifer ingrowth is occurring and
existing shrubs may now be inaccessible and unpalatable. These observations should be
confirmed and if necessary, early spring burns should be carried out to improve forage on
these winter ranges.
There are plans for prescribed burns on the Gilpin Grasslands Protected Area for spring
2010. Sand to Spooner Creek winter ranges support the majority of ungulates in MU 8-15.
Habitat work should be ongoing across these winter ranges. For mule deer, attention should
be given to the upper elevation forest/grassland interface.
26
Acknowledgements
MNRO thanks pilot Keegan McCabe, Valhalla Helicopters, and Vic Corrie, Range Helicopters,
for their save and skilful flying. I would like to thank several observers: Scott Mackenzie, Barry
Brandow, Dave Webster, Brian Robertson and Brian Harris. Thank you to Garth Mowat and
Brian Harris for their technical input and advice on the draft versions of this report. Finally, the
Ministry of Forests, Lands and Natural Resource Operations recognizes the Habitat Conservation
Trust Foundation and anglers, hunters, trappers and guides who contribute to the Trust, for
making a significant financial contribution to support the Shuswap and Boundary Mule Deer
Composition Survey. Without such support, this project would not have been possible.
Literature Cited
Caughley, G.1974. Bias in aerial survey. J. Wildlife Management. 38:921-933.
Erickson, G.L., Heffelfinger, J.R., and Ellenberger, J. H. 2003. Potential Effects of Hunting and
Hunt Structure on Mule Deer Abundance and Demographics. In: deVos, Jr.J.C., M.R. Conover,
and N.E. Headrick. 2003. Mule Deer Conservation: Issues and Management Strategies.
Berryman Institute Press, Utah State University, Logan Utah.
Harris, Brian. 2010. Mule Deer Management Statement-Management Unit 8-15. BC Ministry of
Environment, Okanagan Region. Penticton, B.C.
Harper, F.E. 1998. Okanagan Mule Deer Harvest Strategy. Unpublished report. B.C. Ministry
of Water Land and Air Protection, Penticton, B.C.
Harris, Brian. 2010b. Upper Shuswap Mule Deer Classification Survey, MU 8-23, January 6,
2010. BC Ministry of Environment, Okanagan Region. Penticton B.C.
Hatter, I, D. Low, B. Lincoln and D. Janz. l989. Deer Management Plan for British Columbia.
1990-2000. BC Fish and Wildlife Branch, Ministry of Environment, Victoria, BC.
Krebs, C. J. 1999. Ecological Methodology, 2nd Edition. Harper Collins, New York
Ministry of Environment, 2010. Southern Interior Mule Deer Harvest Management Procedure.
BC Ministry of Environment Procedure Manual. Victoria, B.C.
Poole, Kim. 2010. Habitat use, seasonal movements, and population dynamics of bighorn sheep
in the Elk Valley – interim report to March 2010. Prepared for the Ministry of Environment and
Teck Coal Limited, Cranbrook and Sparwood BC, respectively.
27
RISC (Resources Information Standards Committee). 2002. Aerial-based inventory methods for
selected ungulates: bison, mountain goat, mountain sheep, moose, elk, deer and caribou.
Standards for components of British Columbia’s biodiversity No. 32. Version 2.0. Resources
Inventory Committee, B.C. Ministry of Sustainable Resource Management, Victoria, British
Columbia.
Samuel, M. D., E. O. Garton, M. W. Schlegel, R. G. Carson. 1987. Visibility Bias during Aerial
Surveys of Elk in Northcentral Idaho. The Journal of Wildlife Management, Vol. 51, No. 3, pp.
622-630
Stent, Pat. 2010. Kooetnay Mule Deer Composition Surveys: Winter 2009/2010. BC Ministry of
Environment, Kootenay Region. Nelson, B.C.
Thornton, J and Addison C. 2010. Hunter Sample Reports, 1976-2008. Unpublished report.
B.C. Ministry of Enviornment. Victoria, B.C.
Unsworth, J. W., F. A. Leboan, E. O. Garton, D. J. Leptich, and P. Zager. 1998. Aerial survey:
user’s manual. Electronic edition. Idaho Department of Fish and Game, Boise, Idaho.
28
Appendix 1
Appendix 1: Kill data from Region 8 from the 1990s "good years" and 2000s. The table compares
the 5 year average kill (2003-2007) as a percentage of “good years” (1990-1996).
Appendix 1
Region 8 Mule Deer Harvest 1990s vs 2000s
M.U.
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
821
822
823
824
825
826
Average
kill
19901996
336
202
55
203
512
152
104
452
147
228
110
376
49
434
264
37
119
218
102
81
50
Kill
2003
151
91
27
103
358
135
118
284
105
105
98
236
17
280
86
21
60
157
26
33
52
Kill
2004
108
46
46
68
255
113
44
237
95
81
38
205
10
211
60
5
47
135
24
33
23
Kill
2005
205
101
39
240
430
212
162
277
159
164
199
231
15
405
155
39
115
177
35
25
72
Kill
2006
135
120
53
119
452
173
77
323
111
122
111
178
16
275
97
50
39
169
22
16
44
Kill
2007
288
99
24
180
385
156
61
275
143
172
136
263
17
347
128
24
59
231
48
47
42
Region
8
4230
2543
1884
3457
2702
3155
Percent
Average
of
kill last "good"
5 years years
177
53
91
45
38
69
142
70
376
73
158
104
92
89
279
62
123
83
129
56
116
106
223
59
15
31
304
70
105
40
28
75
64
54
174
80
31
30
31
38
47
93
2748
65
29