Collective anti-predator escape manoeuvres through optimal attack and avoidance strategies

Area of Science:

• Collective animal behavior
• Predator-prey dynamics
• Self-organized systems

Background:

• Collective dynamics in self-organized systems arise from individual decision rules responding to social cues and external forces.
• Understanding predator-prey interactions, especially collective escape patterns, requires analyzing social rules, prey behavior, and predator strategies.

Purpose of the Study:

• To investigate the emergence of the 'fountain effect' in collective animal evasions.
• To determine if individual survival maximization explains fountain effects.
• To link prey escape rules and predator attack strategies to observed collective patterns.

Main Methods:

• Drone-based empirical observations of schooling sardines (Sardinops sagax caerulea) and striped marlin (Kajikia audax).
• Spatially-explicit agent-based modeling of predator-prey interactions.
• Analysis of escape angles, social interactions, and predator attack directions.

Main Results:

• The majority of observed predator attacks on sardines resulted in fountain effects.
• Fountain effect dynamics were influenced by the predator's attack direction.
• Agent-based models demonstrated that fountain maneuvers emerge from optimal individual escape angles combined with social interactions.
• Prey escape rules prioritizing predator distance creation were identified.

Conclusions:

• The 'fountain effect' is an emergent property of individual prey maximizing survival by optimizing escape angles and social responses to predator hunting strategies.
• The study provides proximate and ultimate explanations for fountain effects in predator-prey systems.
• Collective patterns in self-organized systems can be explained by considering both social rules and attack strategies.