Journal of Ethology

, 28:67

Escape and alerting responses by Balearic lizards (Podarcis lilfordi) to movement and turning direction by nearby predators

  • William E. CooperJr
  • Dror Hawlena
  • Valentín Pérez-Mellado

DOI: 10.1007/s10164-009-0157-9

Cite this article as:
Cooper, W.E., Hawlena, D. & Pérez-Mellado, V. J Ethol (2010) 28: 67. doi:10.1007/s10164-009-0157-9


Escape theory predicts that prey monitoring an approaching predator delay escape until predation risk outweighs costs of fleeing. However, if a predator is not detected until it is closer than the optimal flight initiation distance (FID = distance between predator and prey when escape begins), escape should begin immediately. Similarly, if a change in a nearby predator’s behavior indicates increased risk, the optimal FID increases, sometimes inducing immediate escape. If a predator that has been standing immobile near a prey suddenly turns toward the prey, greater risk is implied than if the predator turns away. If the immobile predator suddenly moves its foot without turning, it might be launching an attack. Therefore, we predicted that frequency of fleeing and preparation to flee are greater when a predator turns toward than away from prey and that frequency of fleeing when a predator suddenly moves decreases as distance between predator and prey increases. We verified these predictions in the Balearic lizard Podarcis lilfordi in field experiments in which an investigator simulated the predator. Lizards fled and performed alerting responses indicating readiness to flee more frequently when the predator turned toward than away from them, and fled more frequently the nearer the predator.


Antipredatory behaviorEscape behaviorPredation riskTurn directionSquamata

Copyright information

© Japan Ethological Society and Springer 2009

Authors and Affiliations

  • William E. CooperJr
    • 1
  • Dror Hawlena
    • 2
  • Valentín Pérez-Mellado
    • 3
  1. 1.Department of BiologyIndiana University Purdue University Fort WayneFort WayneUSA
  2. 2.Department of Life SciencesBen-Gurion University of the NegevBeershebaIsrael
  3. 3.Departamento de Biologia AnimalUniversidad de SalamancaSalamancaSpain