Short-term environmental variation in predation risk leads to differential performance in predation-related cognitive function

Predation produces strong selection on numerous traits affecting prey survival, such as morphology or behaviour. However, little is known about the influence of predation on behavioural traits that reflect cognitive abilities. Two studies have shown negative relationships between predation pressure and performance in foraging-related tasks in different populations of fish. Whether these differences are due to population differences or plasticity is unknown. In addition, little is known of the effect of predation risk on predator-related cognitive function. Here, I exposed woodfrog, Lithobates sylvaticus, tadpoles to a high or low level of background risk using injured conspecific cues for 4 days. Following this period, I conditioned them to recognize a novel predator as a threat. I compared the intensity of the learned response between the two groups the following day, and compared retention after 10 days. I found that high-risk tadpoles learned to respond to the predator with a greater intensity of antipredator response and retained the response longer compared to low-risk tadpoles. This is the first study to demonstrate that recent history of predation risk can affect the cognition of prey, demonstrating plasticity in a relatively fixed learning mechanism. My results also raise questions regarding the existence of cross-contextual cognitive trade-offs in animals: increased cognition in predation-related tasks may come at the expense of foraging-related tasks. (C) 2014 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.