Shuswap and Boundary Mule Deer Composition Surveys: December 2010

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1 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

2 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 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 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

3 Contents List of Tables... 4 List of Figures... 4 List of Appendixes... 5 Introduction... 6 Study Areas... 8 Shuswap MU Boundary MU 812,814, Methods Survey Area Selection Survey Procedures Classification Data Analysis Ground Surveys Results Shuswap Boundary Elevation Distribution Other Species Discussion Distribution Buck ratios Shuswap MU Boundary MU 8-12, 8-14, Survey Methods Recommendations Methods Management Acknowledgements

4 Literature Cited Appendix List of Tables Table 1: Classification of mule deer observed during the aerial composition survey in MU 8-23 on December 2 nd and 3 rd, Table 2: The encounter rate (deer/hr) of mule deer during aerial composition surveys in MU 8-23 on December 2 nd and 3 rd, Table 3: Classification of mule deer observed during the aerial composition survey in MU 8-12 and 8-14 on December 10 th, 11 th and 15 th, Table 4: Classification of mule deer observed during the aerial composition survey in MU 8-15 on December 11 th and 15 th, Table 5: The encounter rate (deer/hr) of mule deer during aerial composition survey in MU 8-14 and 8-15 on December 10 th, 11 th and 15 th, Table 6: Summary of species observed during aerial surveys in MU 8-14,15,23 in December, Table 7: The percent of bucks observed with at least one doe during composition surveys across the Okanagan and Kootenay Regions in 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 Figure 2: Region 8 and MU 8-15 hunter days / kill and mule deer harvest for MU 8-15 from 1990 to Figure 3: Map showing areas surveyed for mule deer during composition surveys, December Figure 4: Map showing ungulate observations scaled to group size during the Shuswap survey December, Figure 5: Map showing flight path for the mule deer composition survey in the Shuswap December, Figure 6: Map of ungulate observations scaled to group size for the west Boundary survey December, Figure 7: Map of ungulate observations scaled to group size for the east Boundary survey December, Figure 8: Map showing flight path for the mule deer composition survey in the west Boundary December,

5 Figure 9: Map showing flight path for the mule deer composition survey in the east Boundary December, Figure 10: Elevation of mule deer observed in MU 8-23, 8-12, 8-14 and 8-15 from composition surveys December Elevation was determined by joining GPS waypoints observations to the closest 20 m contour in ArcGIS Figure 11: Bucks / 100 does (buck to doe ratio) with 90% confidence intervals for January 2010 and December 2010 MU Figure 12: Bucks / 100 does (buck to doe ratio) with 90% confidence intervals for 2000, 2002, 2008 and 2010 in MU All but the 2010 data were surveyed in January; antler drop may bias the buck ratio lower Figure 13: Hunter kill and harvest in MU 8-15 from 1987 to 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 ( ) as a percentage of good years ( )

6 Harvest 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 , 24, 25 Combined Figure 1: Mule deer harvest in MU 8-23 compared to 8-13, 24 and 25 (combined) in Region 8 from 1990 to

7 Harvest Hunter Days / Kill 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) Harvest 8-15 Days / Kill Region Days / Kill Figure 2: Region 8 and MU 8-15 hunter days / kill and mule deer harvest for MU 8-15 from 1990 to 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 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

8 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 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, 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

9 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 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

10 Figure 3: Map showing areas surveyed for mule deer during composition surveys, December 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

11 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 km/hour were targeted while maintaining a distance of 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 ( 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 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

12 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 2 nd and 3 rd, were completed before the weather turned unfavourable for flying. South Fork, Currie Creek and Cherry Ridge were surveyed on December 2 nd ; Byers Range and Montgomery were surveyed on December 3 rd. 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, 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

13 Table 1: Classification of mule deer observed during the aerial composition survey in MU 8-23 on December 2 nd and 3 rd, MU 8-23 Fawns Does Unclassified <4pt Bucks >4pt Bucks All Bucks Total South Fork & Currie Creek Cherry Ridge Byers Ridge Montgomery Total Figure 4: Map showing ungulate observations scaled to group size during the Shuswap survey December, 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

14 Table 2: The encounter rate (deer/hr) of mule deer during aerial composition surveys in MU 8-23 on December 2 nd and 3 rd, Winter Range Time on Survey (hr) Encounter Rate (deer/hr) South Fork & Currie Creek 2.3 hr 25 Cherry Ridge 1.1 hr 16 Byers Range 3.7 hr 57 Montgomery 0.8 hr 112 Figure 5: Map showing flight path for the mule deer composition survey in the Shuswap December, Boundary Three survey days, December 10 th, 11 th and 15 th, were completed across MU 8-12, 8-14, and 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 10 th, Survey conditions were 14

15 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 6-21). I calculated 87 fawns: 100 does (CI 78-93) in MU Table 3: Classification of mule deer observed during the aerial composition survey in MU 8-12 and 8-14 on December 10 th, 11 th and 15 th, MU 8-12 & 8-14 Fawns Does Unclassified <4pt Bucks >4pt Bucks All Bucks Total Johnstone Ck Ingram Ck Total A low cloud ceiling prevented us from surveying above 1120m elevation 15

16 Figure 6: Map of ungulate observations scaled to group size for the west Boundary survey December, 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 Table 4: Classification of mule deer observed during the aerial composition survey in MU 8-15 on December 11 th and 15 th, MU 8-15 Fawns Does Unclassified <4pt Bucks >4pt Bucks All Bucks Total Toronto to Lynch Ck Sand to Spooner Ck Total

17 Figure 7: Map of ungulate observations scaled to group size for the east Boundary survey December, 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 10 th, 11 th and 15 th, Winter Range Time on Survey (hr) Encounter Rate (deer/hr) Ingram Toronto to Lynch Sand to Spooner

18 Figure 8: Map showing flight path for the mule deer composition survey in the west Boundary December,

19 Figure 9: Map showing flight path for the mule deer composition survey in the east Boundary December, 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

20 Proportion Does & Fawns <4pt >4pt Figure 10: Elevation of mule deer observed in MU 8-23, 8-12, 8-14 and 8-15 from composition surveys December Elevation was determined by joining GPS waypoints observations to the closest 20 m contour in ArcGIS. Other Species Elevation (m) 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 We counted 124 bighorn between Sand and Spooner Creek, which was similar to the previous aerial survey count of 129 in March, 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

21 Table 6: Summary of species observed during aerial surveys in MU 8-14,15,23 in December, Species MU Unclassified Juvenile Adult Female Adult Male Total Elk Bighorn Sheep White-tailed Deer Moose 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 10 th 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 10 th 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

22 early December. We suggest that mule deer composition surveys be completed before December 5 th, 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 Survey Dates MU % Bucks with Does Sample Size November 22 & 23 rd, ,21, December 2 & 3 rd, December 10, 11 & 15 th, , 14, December 15 & 22 nd, ,06, January 6 th, 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

23 Bucks / 100 Does survey. The overall sample size was greater in December 2010 (n= 369) than January 2010 (n=195), resulting in a more precise estimate January 2010 December 2010 Figure 11: Bucks / 100 does (buck to doe ratio) with 90% confidence intervals for January 2010 and December 2010 MU Boundary MU 8-12, 8-14, 8-15 Composition numbers for mule deer are limited in MU 8-12 and 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 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

24 Hunter Numbers Hunter Kill Bucks / 100 Does suggests that the south slope ranges (i.e. Sand to Spooner Creek) are currently supporting the bulk of the wintering mule deer in MU Figure 12: Bucks / 100 does (buck to doe ratio) with 90% confidence intervals for 2000, 2002, 2008 and 2010 in MU 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 Figure 13: Hunter kill and harvest in MU 8-15 from 1987 to

25 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

26 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 Sand to Spooner Creek winter ranges support the majority of ungulates in MU Habitat work should be ongoing across these winter ranges. For mule deer, attention should be given to the upper elevation forest/grassland interface. 26

27 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 Bias in aerial survey. J. Wildlife Management. 38: Erickson, G.L., Heffelfinger, J.R., and Ellenberger, J. H 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 Mule Deer Conservation: Issues and Management Strategies. Berryman Institute Press, Utah State University, Logan Utah. Harris, Brian Mule Deer Management Statement-Management Unit BC Ministry of Environment, Okanagan Region. Penticton, B.C. Harper, F.E 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, 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 BC Fish and Wildlife Branch, Ministry of Environment, Victoria, BC. Krebs, C. J Ecological Methodology, 2nd Edition. Harper Collins, New York Ministry of Environment, Southern Interior Mule Deer Harvest Management Procedure. BC Ministry of Environment Procedure Manual. Victoria, B.C. Poole, Kim Habitat use, seasonal movements, and population dynamics of bighorn sheep in the Elk Valley interim report to March Prepared for the Ministry of Environment and Teck Coal Limited, Cranbrook and Sparwood BC, respectively. 27

28 RISC (Resources Information Standards Committee) 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 Visibility Bias during Aerial Surveys of Elk in Northcentral Idaho. The Journal of Wildlife Management, Vol. 51, No. 3, pp Stent, Pat Kooetnay Mule Deer Composition Surveys: Winter 2009/2010. BC Ministry of Environment, Kootenay Region. Nelson, B.C. Thornton, J and Addison C Hunter Sample Reports, 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 Aerial survey: user s manual. Electronic edition. Idaho Department of Fish and Game, Boise, Idaho. 28

29 Appendix 1 Appendix 1: Kill data from Region 8 from the 1990s "good years" and 2000s. The table compares the 5 year average kill ( ) as a percentage of good years ( ). M.U. Average kill Kill 2003 Region 8 Mule Deer Harvest 1990s vs 2000s Kill 2004 Kill 2005 Kill 2006 Kill 2007 Average kill last 5 years Percent of "good" years Region