Innate behavioural mechanisms and defensive traits in ecological models of predator-prey types

TL;DR

This paper develops a predator-prey model incorporating inducible defenses, spatial dynamics, and taxis, revealing how adaptive strategies influence ecological stability, pattern formation, and species coexistence.

Contribution

It introduces a novel predator-prey model with inducible defenses and extends it to include spatial diffusion and taxis, providing new insights into ecological stability and pattern formation.

Findings

Defensive mechanisms stabilize predator-prey dynamics.

Moderate interference increases predator populations despite low prey defenses.

Taxis reduces pattern formation and stabilizes the system.

Abstract

There are various examples of phenotypic plasticity in ecosystems that serve as the basis for a wide range of inducible defences against predation. These strategies include camouflage, burrowing, mimicry, evasive actions, and even counterattacks that enhance survival under fluctuating predatory threats. Additionally, the ability to exhibit plastic responses often influences ecological balances, shaping predator-prey coexistence over time. This study introduces a predator-prey model where prey species show inducible defences, providing new insights into the role of adaptive strategies in these complex interactions. The stabilizing impact of the defensive mechanism is one of several intriguing outcomes produced by the dynamics. Moreover, the predator population rises when the interference rate increases to a moderate value even in the presence of lower prey defence but decreases monotonically for stronger defence levels. Furthermore, we identify a bistable domain when the handling rate is used as a control parameter, emphasizing the critical role of initial population sizes in determining system outcomes. By considering the species diffusion in a bounded region, the study is expanded into a spatio-temporal model. The numerical simulation reveals that the Turing domain decreases as the level of protection increases. The study is subsequently extended to incorporate taxis, known as the directed movement of species toward or away from another species. Our investigation identifies the conditions under which pattern formation emerges, driven by the interplay of inducible defences, taxis as well as species diffusion. Numerical simulations demonstrate that including taxis within the spatio-temporal model exerts a stabilizing influence, thereby diminishing the potential for pattern formation in the system.