1. Small Mammal Dispersion from:Frank Stegemann Tobias Schwatinski Kai Dischereit

2. 1 Introduction Environmental and agricultural benefits : -habitat for a large number of wildlife species -improved water quality -improved productivity of adjacent land for livestock grazing -fertile soils for agricultural production when drained BUT - Damage wood -> Cause costs Need to limitate beaver populations to a certain number of beavers

3. …rate of change of beavers/square-inch in controlled area A …rate of change of beavers/square-inch in uncontrolled area B …functions for isolated populations …function of relationship between beavers of both areas -> social fence 1 Mathematical Formulation of the Social Fence Hypothesis

4. Population of beavers in both areas without influence of human and themselves Area 1 -> logistic model Area 2 -> exponential model 1 Mathematical Formulation of the Social Fence Hypothesis

5. Migration from Y to X 1 Mathematical Formulation of the Social Fence Hypothesis within-group aggression of Y between-group aggression between X and Y …carrying capacity …constant rate of beavers/square mile/year

6. 2 The Social Fence Formulation without Trapping

8. 3 The Social Fence Formulation with Trapping p > 0

9. 3 The Social Fence Formulation with Trapping Trapping P = 25% equilibrium point x = 55%