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WILD HORSE MANAGEMENT SYSTEM: POPULATION PROJECTION & COSTING MODEL. EconFirst Associates LLC with HSUS Support. Horse Population Management. Over Populated Range. Foaling. Gather?. No. Yes. Remove?. No. Yes. Contraception. Short & Long Term Holding. Desired Range Population.
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WILD HORSE MANAGEMENT SYSTEM: POPULATION PROJECTION & COSTING MODEL EconFirst Associates LLC with HSUS Support
Horse Population Management Over Populated Range Foaling Gather? No Yes Remove? No Yes Contraception Short & Long Term Holding Desired Range Population Adoption
Goals of Wild Horse Management • Achieve target range populations • Treat wild horses humanely • Respect Budget Constraints
CURRENT APPROACH NOT SUSTAINABLE • Range populations grow as much as 25% /Yr. • Therefore frequency & size of removals grow • High pop. growth means more young horses • Therefore longer time in holding facilities
The BUDGET must be considered • Federal budget constraints will limit BLM’s Management Options • Therefore costs must be considered if this committee’s recommendations are to endure
Population Model Starting range population Foaling Probability Add Foals Environmental Impacts (weather, drought, etc.) Contraception Effectiveness Survival Probability Subtract Deaths Gather Efficiency Subtract Removals Short & Long Term Holding Ending Range Population
Simulates Probable Population Outcomes 1 2 3 4 5 6 7 8 9 10 Year
This System Adds Optimization to Simulation • Optimize Population Intervention • Optimize Use of Scarce Resources • Optimize Population Target Levels • Optimize within Budget Constraints
Successful Management will Optimize Initial Plan and Adjust as Data is Augmented
Planning is a Moving Target Given Variability of Range Environments Active Interaction with Simulations
Successful Management will Include all HMAs
Successful Management will Require Better Data Collection
MODEL COMPONENTS • Dynamic Population Simulation model • Economic Costing Model • Management Optimization Model • Population & Range Database System
The Projection Model • Simulates single or multiple HMAs • Adjusts as new data becomes available • Integrates population simulation and costs • Combines simulation and optimization to reach population and cost targets
A Tool to Manage Wild Horse Areas • Find optimum mix and timing of • Gathers, Removals and Fertility Treatment
Optimization under Uncertainity • Timing & Frequency of Gathers • Extent of Fertility Treatment • Reach or adjust AML targets • Subject to Cost constraints
Reverse Optimization • Given budget, determine reachable AMLs • Subject to carrying capacity constraints • Subject to min-max levels
Simulation Example for Single HMA
Single HMA: Baseline Simulation if no Mgt. Year 12 = 10,418 Base Year = 3,750
If Planned Removals every 3 yrs Base Year 3,750 AML target = 333
Planned Removals every 3 yrs – relaxed AML AML target = 1,500
Cost Comparisons *Present value at 4.3% (CBO)
Simulation Approximation for All HMAs
Young Horses Expand Rapidly All approach Log Normal distribution over time
Tests of Robustness • Does approach work with different initial population distributions? • Does it work for multiple HMAs? • Does it incorporate new data as it becomes available?
All HMAs : 3 Year Phase-in Removals Only Base Year = 40,044 AML target = 24,750
All HMAs : 3 Year Phase-in With Treatment AML target = 24,750
Cost Comparison All HMAs *Present value at 4.3% (CBO)
MODEL COMPONENTS • Dynamic Population Simulation model • Economic Costing Model • Management Optimization Model • Population & Range Database System
WILD HORSE MANAGEMENT SYSTEM: POPULATION PROJECTION & COSTING MODEL EconFirst Associates LLC with HSUS Support