Behavioural response of prey to repeated attacks by non-coordinating predators

TL;DR

This study explores how prey respond to repeated attacks by multiple non-coordinating predators, revealing complex behavioral transitions and non-additive predation effects.

Contribution

The paper introduces an agent-based model to study prey responses to persistent multi-predator attacks, revealing new insights into group dynamics and predation success.

Findings

Prey exhibit a transition from cohesive to split-and-escape behavior based on predator angular configuration.

Attacking the nearest prey is the most effective strategy, while targeting the group center causes splitting.

Higher prey coordination leads to faster population decline, suggesting detrimental effects of excess alignment.

Abstract

Collective behaviour is a ubiquitous phenomenon entailing the emergence of fascinating pattern formations in organisms. Reduction of predation risk is presumed to be a major factor contributing towards the evolution of such behaviour. However, the effect of persistent attacks by multiple predators on the behavioural response of the prey remains largely unexplored. The current work aims to address this issue using an agent-based approach employing an underdamped Langevin model. A continuous transition in prey response from a cohesive escape to split-and-escape is discussed with respect to the angular configuration of the predators before the attack. The statistics show that the attack on the nearest prey is the most successful pursuit strategy, while alternative strategies, such as attacking the centre of the group, have conspicuous ancillary effects, such as group splitting. A long-term temporal study of the system indicates a counter-intuitive faster decay of prey numbers at higher intensity of prey coordination, hinting at possible excess alignment and its detrimental effects in the case of successive predator attacks. The effect of predation is found to be non-additive even if non-coordinating predators are considered, highlighting the non-scalability of predator-prey systems and urging further scrutiny of the dynamics of group hunting in such systems.

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