Extinction time in growth models subject to binomial catastrophes

Abstract

Populations are often subject to catastrophes that cause mass removal of individuals. Many stochastic growth models have been considered to explain such dynamics. Among the results reported, it has been considered whether dispersion strategies, at times of catastrophes, increase the survival probability of the population. In this paper, we contrast dispersion strategies comparing mean extinction times of the population when extinction occurs almost surely. In particular, we consider populations subject to binomial catastrophes, that is, the population size is reduced according to a binomial law when a catastrophe occurs. Our findings delineate the optimal strategy (dispersion or non-dispersion) based on variations in model parameter values.