Larval amphibians learn to match antipredator response intensity to temporal patterns of risk

The importance of temporal variability in risk has recently come to the forefront of research examining the behavioral ecology of predator--prey relationships. Temporal variability has been known to drive patterns of behavioral responses associated with foraging, reproduction, and territorial defense of prey animals. However, it is unknown if such behavioral responses are a result of selective depredation, which leads to innate temporal patterns of behavior, or, alternatively, are a result of learning by the prey. Here, we investigated whether larval wood frog (Rana sylvatica) tadpoles can learn to adjust the intensity of their antipredator responses to match the temporal patterns of risk they experience. Tadpoles were exposed to the odor of a predatory salamander paired with injured conspecific cues (salamander present and feeding) during the morning and received the salamander odor alone in the evening (salamander present but not feeding--morning risk treatment), whereas another group received the opposite treatments (evening risk treatment). The 2 groups were treated for 9 days. When subsequently exposed to salamander alone in the evenings, the tadpoles from the evening risk treatment responded with greater antipredator response intensity than the tadpoles from the morning risk treatment. This indicates that tadpoles have the ability to learn the change in predation risk they experience throughout the day and respond to such threats with an intensity reflecting their vulnerability to the predators. Copyright 2008, Oxford University Press.