How moths escape bats: predicting outcomes of predator-prey interactions

Area of Science:

• Behavioral Ecology
• Biomechanics
• Predator-Prey Dynamics

Background:

• Mathematical models of predator-prey interactions often lack empirical validation from real-world encounters.
• Understanding escape strategies is crucial for explaining prey survival rates and co-evolutionary arms races.

Purpose of the Study:

• To empirically test existing mathematical models of predator-prey pursuit and escape.
• To identify key factors determining prey escape success during aerial attacks.
• To develop a novel geometrical model of predation based on observed interactions.

Main Methods:

• Recorded 235 bat (Myotis volans) attacks on moths using multi-camera infrared videography in an outdoor enclosure.
• Reconstructed 3-D flight trajectories of bats and moths from 50 high-quality attack events.
• Utilized logistic regression to analyze the influence of kinematic variables on prey escape success.

Main Results:

• Bats captured only 37.5% of evasive prey despite superior kinematic abilities (velocity, deceleration, turning).
• Prey radial acceleration and escape angle were the most significant predictors of successful evasion (88% accuracy).
• Moths typically escaped by turning towards predator-flanking 'safety zones' with high radial acceleration, contrary to fleeing directly away.

Conclusions:

• Existing 'turning gambit' models partially explain prey evasion but underestimate escape thresholds and neglect escape angle.
• Moths employ a turning strategy towards safety zones, suggesting this tactic may be common in aerial pursuits.
• Findings support a novel geometrical model of predation, with implications for understanding the co-evolution of predator-prey strategies.