Feeding regime and food availability determine behavioural decisions under predation risk in Pleurodema thaul (Anura: Leiuperidae) tadpoles

Abstract

Movement makes prey more vulnerable to predators. Antipredator responses usually have associated costs such as reduced feeding activity, and decisions made under predation risk may be affected by the feeding state of the prey. In this study, we evaluated whether food regime influences antipredator behavioural responses of Pleurodema thaul tadpoles (diet treatment) before adding food or water (incentive treatment) while the tadpoles were exposed to alarm cues. Under predation risk, normally fed tadpoles showed decreased overall activity, whereas poorly fed tadpoles spent more time feeding after food was provided. Tadpoles in all treatments decreased their swimming activity but not their feeding activity. Our study showed that swimming behaviour was more sensitive to predation risk than feeding behaviour. We suggest that the motivational state of tadpoles under different environmental conditions should be considered when behavioural patterns are analyzed to understand short-term trade-offs between foraging requirements and predator avoidance.