Mule Deer Informational AGENDA #19-C MODELS AND POPULATION ESTIMATES CODY SCHROEDER – NDOW GAME DIVISION
The Process: How do we develop quota recs? Survey Population Quota Data Models Array Harvest Data
Population Models: Why do we estimate numbers? No survey method has perfection detection to count all animals Populations constantly change because of mortality, births, immigration, emigration To provide an estimate of abundance for tag allocation (quota) Limiting factors
Harvest Data ▪ Mandatory harvest reporting for all big game species ▪ New system, 98% reporting rate ▪ Sex ▪ Age ▪ Hunt Unit or Unit Group ▪ # of antler points ▪ # animals wounded or tracked
Statewide % 4-Point or greater 50% % 4 point or greater 45% 40% % 4 Point or greater 35% 30% 25% 20% 15% 10% 5% 0% 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 Deer Status: Harvest Trends
Population Models: How do we estimate populations? ▪ NDOW uses a deterministic spreadsheet model ▪ Deterministic = no stochasticity (random variation) ▪ Basic input parameters ▪ Initial population size ▪ Recruitment data (fawn:doe ratio) ▪ Harvest data (we subtract bucks, does, and fawns) ▪ Survival rates ▪ Buck:doe ratio used a qualitative measure to calibrate models
Population Models: Integrated Population Models Count Data Telemetry Data Harvest Data Environmental Covariates
Integrated Population Model PopR software developed by Dr. Paul Lukacs and Josh Nowak University of Montana Contracted through 2021
Change-in-Ratio Spreadsheet Selleck-Hart Estimator Model Model 300 30 Population Esimate (Thousands) 250 25 Pop Estimate Deer Harvest (Thousands) Deer Harvest 200 20 150 15 100 10 NDOW Heritage Program 50 5 $25 million spent to date 0 0 1976 1983 1990 1997 2004 2011 2018
Statewide Fall Deer Survey (1975- Current) Observed Buck Ratio 3 per. Mov. Avg. (Observed Buck Ratio) 35 30 25 Bucks per 100 Does 20 15 10 5 0 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 Year
Statewide Fall Deer Survey (1975-Current) Fawn:Doe Ratio 3 per. Mov. Avg. (Fawn:Doe Ratio) 120 100 Fawns per 100 Does 80 60 40 20 0 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 Survey Year
Statewide Spring Deer Survey (1975-Current) Fawn:Adult Ratio 3 per. Mov. Avg. (Fawn:Adult Ratio) 70 60 Fawns per 100 Adults 50 40 30 20 10 0 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 Year
Summary of Agenda Item #19-C q Process of quota development q NDOW uses models to estimate populations q Inputs include survey data, harvest data, survival rates q Population trends have fluctuated over time q In process of developing new web-based models
Mule Deer Informational AGENDA # 19-D DEVELOPMENT OF QUOTAS FROM SURVEY AND POPULATION DATA CODY SCHROEDER – NDOW GAME DIVISION
Quota Development Process: 1 2 3 / Determine # animals Distribute harvest into Expand harvest to available for harvest weapon classes quotas • Population estimate • Based on previous • Divide harvest rate year’s demand by hunt success (%) • Buck to Doe Ratio
Demand: Measure of interest based on 1 st Choice applications from year prior ARCHERY MUZZELOADER ANY LEGAL WEAPON
Mule Deer : Hunt Success Resident Antlered Mule Deer Hunt Success Archery Muzzleloader ALW 60 Hunt Success Rate (%) 50 40 30 20 10 0 2016 2017 2018
Quota Development Process: 2019 MULE DEER QUOTA ARRAY UNIT GROUP: 171-173 - Northwestern Nye and Southern Lander Counties PREHUNT ESTIMATE % YOUTH HUNT HUNT ADULT ADULT BUCK HARVEST Comp. 1235 1235 BUCKS DOES RATIO AS DOES Tags % Success Early Late 1150 2543 45 39% 16 4 TOTAL 3693 RATE DESIRED HUNT FIRST CHOICE THREE YEAR AVERAGE Antlerless OF DOE DOE 1181 APPLICATIONS--DEMAND HUNTER SUCCESS RATES HUNTER HARVEST HARVEST QUOTA RIFLE MUZZL. ARCH. YOUTH RIFLE MUZZL. ARCH. SUCCESS 0% 0 0 53.7% 6.1% 15.1% 53.5% 32.0% 26.3% 9.3% POST HUNT HUNT HUNT HUNT HUNT HUNT HUNT HUNT 1331 1371 1341 1107 1331 1371 1341 BUCK DESIRED REPRTD. RES. RES. RES. RES. NR. NR. NR. RES. NR RATIO BUCK BUCK RIFLE MUZZL. ARCH. RIFLE MUZZL. ARCH. TOTAL TOTAL OBJ. HARVEST HARVEST QUOTA QUOTA QUOTA QUOTA QUOTA QUOTA QUOTA QUOTA QUOTA 30 387 322 487 75 180 144 34 8 20 886 78
Mule Deer Harvest Guidelines Standard 25 – 35 Bucks per 100 Does • Most Units across the state Alternative 30 – 40 Bucks per 100 Does • WR – 014, 194-196 • ER – 065, 081, 114-115, 131-134 • SR – 221-223, 241 - 245 Non-Standard Hunt Success (3 yr avg) • 35 – 45% for 6 Unit Groups • ≥ 45% for 8 Unit Groups
Public Process NDOW Wildlife CABs Commission General Public QUOTA
Public Review and Wildlife Commission Process o NDOW posts official quota recommendations in late April o County Advisory Boards (CAB’s) receive NDOW quota recommendations o CAB’s hold public meetings to discuss quota recommendations o Nevada Board of Wildlife Commission meeting in May to approve NDOW’s quota recommendations o General public and CABs provide input o Commission makes final decision on tag quotas
Mule Deer Restoration Efforts o $25 million dollars spent on sagebrush habitat restoration by Heritage Program since 1996 o Benefits mule deer and many other wildlife species o Over 800 mule deer radio-collared by NDOW since 2010 o Map crucial habitat and corridors o Survival rates o Collect information on body condition
Summary of Agenda Item #19-D q Quota process is a 3-step process q Quota array based on demand/success q Population estimate q Demand (previous year) q Hunt success (3-year avg) q Resident (90%) Non-resident (10%) split q Public process involving NDOW, CABs, Wildlife Commission q NDOW has spent millions of $$ in habitat and research on mule deer over last two decades
Thank You
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