Collective Adaptation in Multi-Agent Systems: How Predator Confusion Shapes Swarm-Like Behaviors

TL;DR

This paper investigates how predator confusion influences the evolution of swarm-like behaviors in multi-agent systems, demonstrating that risk dilution and information exchange variations shape collective adaptation through reinforcement learning.

Contribution

It introduces a predator confusion hypothesis as a driver for the emergence of group formations and compares local versus global perception models in evolving collective behaviors.

Findings

Dilution of risk promotes group formation in prey agents.

Predator confusion can drive the evolution of collaborative behaviors.

Variations in information exchange affect collective behavior dynamics.

Abstract

Popular hypotheses about the origins of collective adaptation are related to two basic behaviours: protection from predators and a combined search for food resources. Among the anti-predator explanations, the predator confusion hypothesis suggests that groups of individuals moving in a swarm aim to overwhelm the predator while the dilution of risk hypothesis suggests that the probability of a single prey being targeted by a predator is lower in larger groups. In this paper, we explore how emergent behaviors arise from a predator-driven process as an adaptive response to external stimuli perceived as threatening. Moreover, we suggest a predator confusion process to provide a selective pressure for the prey to evolve group formations. We analyze the foraging and prey-predator dynamics evolved in terms of group density and formation, behavior consistency, predator evasion and success rate, and foraging rate. Two agents' perceptual models are compared. A local observation model, where agents can only see what's in their immediate vicinity, and a global observation model, where agents are able to see the predator at all times. Both models were evolved for predator avoidance, foraging and collision avoidance, using reinforcement learning in a simulated game environment. Our results suggest that the dilution of risk factor is sufficient to evolve group formations, and the predator confusion effect could play an important role in the evolution of collaborative behaviors. Finally, we show how variations in the information exchange of this social order can impact the global collective behaviors.