Analysis of steady-state populations with the gamma abundance model: application to Tribolium

A model for the abundance of adult populations of Tribolium is in the form of a stochastic differential equation containing adult recruitment and mortality rates perturbed by multiplicative noise. A deterministic version of the model (an ordinary differential equation) predicts a fixed, stable equilibrium; the stochastic model predicts a stationary probability distribution for population size. The model can be approximated closely by a stochastic logistic equation having a gamma distribution as a stationary solution. -from Authors