Each habitat patch runs logistic growth with mortality from human pressure, minus emigration and plus immigration through corridors (a simple metapopulation / rescue-effect model):
dN/K = r·N·(1-N/K) - m·N + corridor·Σ(inflow)
K_patch ∝ protected_area, m ∝ human_pressure
Fragmenting one large habitat into many small patches lowers each patch's carrying capacity and raises edge effects, so total sustainable population drops even though total area is unchanged. Corridors between patches restore gene flow and let animals recolonize a patch after a local crash — the "rescue effect" — which is why wildlife corridors are a cornerstone of real conservation planning.
- Habitat fragmentation — splits the reserve into more, smaller patches (visually: more separate green islands).
- Corridor connectivity — how strongly animals move between adjacent patches; 0% isolates every patch.
- Human pressure — added mortality rate representing hunting, land conversion, and disturbance.
- Protected area effort — raises each patch's carrying capacity and lowers effective pressure.
Real-world application: this is the logic behind wildlife corridor projects like Yellowstone-to-Yukon and India's tiger reserve networks, which link fragmented habitat so populations aren't isolated into extinction.