Lotka-Volterra Calculator

Find the equilibrium of a predator-prey system.

Equilibrium prey 200
Equilibrium predator 120

Formula: N* = b/c, P* = r/a

Step-by-step with your numbers:
1. Values used:
2. Prey growth rate (r) = 1.2
3. Predation rate (a) = 0.01
4. Predator death rate (b) = 0.8
5. Predator growth rate (c) = 0.004
6.
7. Equilibrium prey = 200
8. Equilibrium predator = Prey growth rate (r) / Predation rate (a) = 1.2 / 0.01 = 120
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The Lotka-Volterra equations model how predator and prey populations cycle.

How the Math Works

The Lotka-Volterra Calculator determines the equilibrium point of a predator-prey system by solving for the stable population values where growth and decline rates balance. At equilibrium, the rates of change for both species are zero. The formula N* = b/c calculates the prey population equilibrium, where b represents prey birth rate and c is the predation rate. Similarly, P* = r/a gives the predator population equilibrium, with r as prey growth rate and a as the conversion efficiency of prey into predator offspring. These values represent the point where neither population grows nor declines, forming a sustainable coexistence.

Practical Applications

To use the calculator, input the four parameters: b (prey birth rate), c (predation rate), r (prey growth rate), and a (predator efficiency). For example, if studying lynx and hare populations, input their specific birth and death rates derived from historical data. The calculator instantly computes N* and P*, helping ecologists predict stable population levels. This is critical for managing reserves, preventing extinctions, or understanding how environmental changes affect species balance over time.

Day-to-Day Use

This mathematical model helps in real-world scenarios like sustainable agriculture, where balancing pest and predator populations can reduce chemical use. It also guides wildlife conservation efforts, such as managing endangered species by predicting optimal habitats. Additionally, businesses use similar dynamics to model competition and market stability, making this calculator a versatile tool for resource planning and ecosystem health monitoring in everyday environmental and economic decisions.

Worked example

r 1.2, a 0.01, b 0.8, c 0.004 → predator 120, prey 200 (steady-state).

FAQ

Is it realistic?

It captures the core cycle but real ecosystems are far more complex.