Full Text
CODY URBAN DEER CLASSIFICATION/TREND SURVEY – 2018 Summary of 2018 Efforts On 12/10/2018 13 WGFD personnel and one city police officer (Trap Heydenberg) conducted a classification/trend survey of deer within the city limits of Cody. The city was broken out into 10 Count Blocks (Figure and all deer encountered were classified into sex/age categories (adult buck, yearling buck, doe, fawn). Surveys were initiated at approximately 2:00 pm and continued until dark, approximately 5:00 pm. Areas out of, but adjacent to the City Limits of Cody were surveyed soon after, it is unknown the influence of these areas on the number of deer in town. These areas included the County Road 2ABN area immediately north of Cody, and the Cooper Lane and Sage Creek areas immediately to the east of Cody. Figure 1. Cody urban deer survey count blocks. ---PAGE BREAK--- Results of 2018 Survey Date: 12/11/2018 Observers: Maichak, Hodges, S. Olson, Lassetter, D. Smith, Swanson, Class, Mong, Gerharter, Sorensen, Winter, Bendzinski, Altermatt, Heydenberg (Cody PD). Total Deer Observations (includes white-tailed deer) Table 1. 2018 observation data for all count blocks. Location Ad Bucks Yrl Bucks Does Fawns Unknown Total CB1 4 3 9 8 0 24 CB2 0 0 0 0 0 0 CB3 0 0 8 6 0 14 CB4 1 1 3 4 0 9 CB5 5 1 12 13 0 31 CB6 0 0 8 5 0 13 CB7 6 2 9 7 0 24 CB8 1 0 5 7 0 13 CB9 2 0 10 8 0 20 CB10 11 3 20 10 0 44 TOTAL 30 10 84 68 0 192 48 bucks:100 does, 81 fawns:100 does Other Areas Adjacent to Cody City Limits 2ABN 0 0 9 9 0 18 Cooper Lane 0 0 0 0 14 14 Lower Sage Creek 0 0 0 0 0 0 Upper Sage Creek 4 1 15 13 0 33 TOTAL 4 1 24 22 14 65 21 bucks:100 does, 92 fawns:100 does A total of 192 mule deer were observed within the City Limits of Cody, and an additional 65 deer (mule deer and white-tailed deer) were observed in adjacent areas. Deer fawn:doe ratios were 81:100 in the City Limits and 92:100 outside the city limits. Total buck ratios were 49:100 in the city limits and 21:100 out of the city limits. Yearling buck ratios were 12:100 in the city limits and 4:100 out of the city limits. ---PAGE BREAK--- Summary of Historical Data The total number of deer observed in the city limits from 2011 to 2018 overall has been showing a decreasing trend (Table 2, Figure The 2018 count was down from the 2017 count of 242 and the average of 263. Within each count block we saw a decrease in total deer counted in 7 count blocks compared to increases in 2 count blocks and no change in 1 count block (Figure We have seen a continual decrease in total number of deer counted in the city limits; however, we continued to see a high buck ratio at 49:100 does and a very high fawn ratio of 81:100 does in 2018. Based on a simple population estimate model that assumes a closed town population, meaning no deer leave town or no new deer come into town, removing no deer out of the population would result in an estimated increase of 20-30 deer. Table 3 shows different removal scenarios with estimated population results. Deer Counts Table 2. Historical total count data (including white-tailed deer) within each Cody count block from 2011 to 2018. Count Block 2011 2012 2013 2014 2015 2016 2017 2018 1 35 42 59 57 60 19 28 24 2 0 0 0 24 9 0 9 0 3 68 41 49 0 26 32 14 14 4 25 16 12 11 15 5 8 9 5 56 46 43 32 43 29 37 31 6 10 18 9 22 33 25 8 13 7 42 25 27 0 0 49 29 24 8 1 8 18 31 34 17 22 13 9 20 33 26 7 22 31 30 20 10 50 30 49 84 41 51 57 44 Total 307 259 292 268 283 258 242 192 Other Areas Adjacent to Cody City Limits 2ABN 55 55 4 33 55 48 0 18 Cooper Lane 114 93 96 78 78 100 2 14 Lower Sage Cr 43 28 10 38 25 11 10 0 Upper Sage Cr 52 58 52 37 79 52 19 33 Total 264 234 162 186 237 211 31 65 ---PAGE BREAK--- ---PAGE BREAK--- Figure 2. Total numbers of deer (including white-tailed deer) counted in all Cody city count blocks from 2011 to 2018. This figure shows overall change in deer numbers between years. The line denotes the polynomial trend line over the course of the last 8 years. ---PAGE BREAK--- Figure 3. Count block data from 2017 to 2018. This figure shows change in deer numbers within each count block from 2017 to 2018. Shown above each set of bars is the change between years (black = increase or no change in numbers, red = decrease in numbers). 0 10 20 30 40 50 60 1 2 3 4 5 6 7 8 9 10 Total Mule Deer Counted Count Block 2017 2018 -6 0 +1 -5 +5 -9 -4 -9 -10 -13 ---PAGE BREAK--- Table 3. Cody town deer estimated influence of different adult doe removal scenarios 25 and 50) on the population. There are many assumptions made in this model that could have influences on the total number estimated for 2019. The estimates do not account for any movement of deer into or out of the town population. The estimates also use the 2018 count data which should be considered a minimum count because it is impossible to have 100% accuracy with a wildlife survey. Annual survival of deer (both adults and fawns) used in the estimates from one year to the next is lower than what we would see in the wild on a “normal” weather year. This lower survival estimate was used to account for the increased risks from car collisions and poor feed quality found in town. The number of potential fawns added to the population in 2019 is based on the average town fawn ratio of 70:100 adult does (2011-2018). Overall, this is a very conservative estimate and may be lower than what is actually found in town. Zero Adult Doe Removals 25 Adult Doe Removals Removal # 0 2018 Count Data Does Fawns Bucks Total Adult Deer Fawn Deer 84 68 40 192 90% 75% # of deer surviving into summer of 2019 76 51 36 # of potential fawns that will add to total numbers in 2019 53 2019 Estimated Total 216 Annual Survival Rate Removal # 25 2018 Count Data Does Fawns Bucks Total Adult Deer Fawn Deer 84 68 40 192 90% 75% # of deer surviving into summer of 2019 51 51 36 # of potential fawns that will add to total numbers in 2019 35 2019 Estimated Total 173 Annual Survival Rate ---PAGE BREAK--- 50 Adult Doe Removals Removal # 50 2018 Count Data Does Fawns Bucks Total Adult Deer Fawn Deer 84 68 40 192 90% 75% # of deer surviving into summer of 2019 26 51 36 # of potential fawns that will add to total numbers in 2019 18 2019 Estimated Total 131 Annual Survival Rate ---PAGE BREAK--- 2018 White-Tailed Deer Counts Count Block 2011 2012 2013 2014 2015 2016 2017 2018 1 0 2 4 0 7 1 0 4 2 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 0 5 0 0 0 0 0 0 0 0 6 0 0 0 0 0 0 0 0 7 0 0 0 0 0 2 0 0 8 0 0 0 4 0 0 0 0 9 0 0 0 0 0 0 0 0 10 0 0 0 0 0 0 0 0 Total 0 2 4 4 7 3 0 4 2ABN 0 8 40 6 0 0 0 8 Cooper Lane 0 0 0 0 0 0 0 0 Lower Sage Cr 79 0 16 45 27 0 0 0 Upper Sage Cr 0 12 36 24 67 34 20 9 Total 79 20 92 75 94 34 20 17