Hierarchical competition models with Allee effects

Genetic Allee effects and their interaction with ecological Allee effects.

It is now widely accepted that genetic processes such as inbreeding depression and loss of genetic variation can increase the extinction risk of small populations. However, it is generally unclear whether extinction risk from genetic causes gradually increases with decreasing population size or whether there is a sharp transition around a specific threshold population size. In the ecological li...

Dynamics of two-species contest competition models subject to Allee effects

In this article, we propose a general two species contest competition model subject to Allee effects and study its population dynamics to obtain insights on how the interplay of Allee effects and contest competitions affect the persistence and the extinction of two competing species. By using the monotone dynamical theory and the properties of critical curves for non-invertible maps, our analys...

Competition can rescue endangered species subject to strong Allee effects

In this article, we study population dynamics of a general two-species discrete-time competition model where each species suffers from strong Allee effects and scramble intra-competition. We focus on how combination of intra-specific and inter-specific competition affect the extinction and coexistence of these two competing species that are subject to strong Allee effects. We derive sufficient ...

Non-Autonomous Periodic Systems with Allee Effects

Allee effects, extinctions, and chaotic transients in simple population models.

Discrete time single species models with overcompensating density dependence and an Allee effect due to predator satiation and mating limitation are investigated. The models exhibit four behaviors: persistence for all initial population densities, bistability in which a population persists for intermediate initial densities and otherwise goes extinct, extinction for all initial densities, and e...