[Mechanistic model for the allee effect and interference in predator population]

Simulation results obtained with an individual-based model describing spatial movement and interactions of predators and prey within a closed rectangular habitat are represented. Movement of each individual animal is determined by local conditions only, thus any collective behaviour emerges due to self-organization. It is shown that the pursuit of the prey by predators leads to the emergence of predator interference manifesting itself at the population level as the dependence of the trophic function on predator abundance (predator-dependence). The stabilizing effect of predator dependence on the dynamics of a predator-prey system has been discussed. The inclusion of prey evasion induces predators' cooperation that further distorts the functional response (the trophic function), leading to a strong Allee effect, i.e. extinction of predator population dropping below a critical threShold. Thus, we propose a simple mechanistic explanation of important but still poorly understood behavioural phenomena that underlie functioning of natural trophic systems.