Pursuit predation across locomotor domains How sensory-motor delay shapes predator-prey encounters

Predators are generally larger, faster, and more powerful than their prey, yet they are remarkably unsuccessful at capturing them. The mismatch is largest in aquatic systems, where predators hold a roughly fivefold speed advantage but succeed in fewer than 10% of encounters. How prey consistently evade biomechanically superior predators is the central question of this thesis.
The turning gambit, an influential geometric model of pursuit, holds that prey escape faster predators through a well-timed turn that exploits a maneuverability advantage. Parameterized with allometric scaling relationships across vertebrates, however, the model predicts that predators should almost always retain a biomechanical advantage, in conflict with observed capture rates.
What the classical model ignores is that predators do not respond instantaneously. Sensory–motor delay, the time required for sensory transduction, neural processing, and motor execution, means a predator always acts on an outdated representation of the prey's position. Incorporating this delay resolves the mismatch and reveals distinct pursuit regimes, driven by the high density of the aquatic medium. On land and in air, outcomes remain sensitive to biomechanical traits such as speed and maneuverability. Underwater the decisive traits are neurological, and escape hinges on prey timing precision and predator sensory–motor delay.
To test the theory, custom-built stereo-camera arrays were deployed on the coral reefs of Curaçao, yielding over 2,000 hours of high-speed footage and hundreds of reconstructed encounters. Prey escape rates and maneuver timing matched the model's predictions. Escape therefore arises not from superior turning ability but from the brief escape window created by the predator's delayed response.