Prey behaviors adapt to different predator attack strategies for survival
Boids of a Feather Flock Together - Evolving Prey Behaviours Under Different Predator Attack Strategies
Artificial Intelligence
Summary
Animals that live and move in groups often do so to avoid predators. This paper explores how these groups change their behavior depending on how a predator attacks them. The authors created a computer simulation of prey and predator interactions, where prey have different ways to move and escape. They found that prey survivors use different strategies—sometimes sticking together, sometimes acting alone—based on the predator’s hunting style. This shows that the best way to stay safe depends on how the predator hunts.
What this means in practice
- •For game developers: Improve non-player character group behaviors by tuning prey escape strategies based on predator attack patterns in simulations or games.
- •For wildlife conservation teams: Simulate animal group dynamics to better predict how prey might respond to different predator threats in managed environments.
Authors
Augusta van Haren, Hanna Hoogen, Luca Pattavina
Abstract
Flocking and schooling are thought to have evolved partly as defences against predation, but how prey should balance social and escape tendencies may depend on the predator's hunting strategy. We extend the predator-prey boids model of Ojo et al. (2023), itself based on Reynolds' boids, by combining six prey movement tendencies (alignment, cohesion, separation, dodge, repel and wiggle) into a single weighted acceleration update, and by reformulating wiggle as a sinusoidal manoeuvre. We then use an evolutionary strategy to optimise the six behaviour coefficients for collective prey survival against four predator hunting strategies: attack-centroid, attack-nearest, attack-random and attack-peripheral. Across five independent trials per strategy, coefficients converged within trials and mean fitness remained stable or increased, although trials often settled in different local optima. Prey survival was highest under attack-centroid and lowest under attack-nearest, in line with our hypotheses. Against attack-centroid, prey evolved individualistic predator avoidance with high escape coefficients, whereas against the other three strategies they largely kept their flock formation. Across all strategies, evolution favoured a low repel coefficient and relatively high dodge and wiggle coefficients. Our results suggest that optimal anti-predator behaviour depends on the interplay between escape tendencies and the predator's hunting strategy.