Fixation in Competing Populations: Diffusion and Strategies for Survival

TL;DR

This paper investigates how dispersal strategies affect the survival of competing species in spatial models, revealing that optimal strategies depend on competition and population fluctuations, with implications for conservation and ecological management.

Contribution

It provides a detailed analysis of dispersal strategies in spatially extended competing species models, highlighting the importance of fluctuations and competition in determining survival strategies.

Findings

Faster dispersal benefits species with intra-species competition.

Slower dispersal is optimal for disadvantaged species without intra-species competition.

Fluctuations significantly influence optimal dispersal strategies.

Abstract

How should dispersal strategies be chosen to increase the likelihood of survival of a species? We obtain the answer for the spatially extended versions of three well-known models of two competing species with unequal diffusivities. Though identical at the mean-field level, the three models exhibit drastically different behaviour leading to different optimal strategies for survival, with or without a selective advantage for one species. With conserved total particle number, dispersal has no effect on survival probability. With a fluctuating number, faster dispersal is advantageous if intra-species competition is present, while moving slower is the optimal strategy for the disadvantaged species if there is no intra-species competition: it is imperative to include fluctuations to properly formulate survival strategies.