Prey respond to predation risk by altering their morphology, physiology, and behavior, responses that may come at a cost to prey foraging and growth. However, their perception of risk may depend upon the environmental context in which the interaction occurs. Here, we examined how food availability influenced prey’s responses to a nonlethal but free-ranging predator. We used an experimental mesocosm set-up of an intertidal system of green crab (Carcinus maenas) predators and dogwhelk snail (Nucella lapillus) prey, with blue mussels as the basal resource. We measured individual Nucella risk-aversion behavior (summed value of their habitat use) and their growth throughout the 28-day experiment. We found that when Nucella were exposed to predation risk, they had greater risk-aversion behavior when food was available as compared to when food was not. We also found that risk-aversion behavior increased over time in all treatments but that individuals exposed to predation risk with food always had greater risk-aversion behavior. Nucella had significantly more growth when provided with food as compared to without. In treatments with food, snails exposed to predation risk had significantly reduced growth compared to those not exposed to risk. In treatments without food, predation risk had no effect on growth. Our results support the hypothesis that greater resource availability significantly increases individual risk responses and the costs of risk avoidance, thus food magnifies risk-induced non-consumptive effects. They provide insights into context-based predation risk effects and how individuals may prioritize safety versus foraging depending upon perceived risk, food availability, and the costs of responding.

中文翻译：

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食物供应对猎物风险诱发性状反应的影响

猎物通过改变其形态、生理和行为来应对捕食风险，这些反应可能会损害猎物的觅食和生长。然而，他们对风险的感知可能取决于相互作用发生的环境背景。在这里，我们研究了食物供应如何影响猎物对非致命但自由活动的捕食者的反应。我们使用了绿蟹（Carcinus maenas）捕食者和狗螺（Nucella lapillus）猎物的潮间带系统的实验性中生态系统设置，以蓝贻贝作为基础资源。我们在 28 天的实验中测量了 Nucella 个体的风险规避行为（栖息地利用的总价值）以及它们的生长情况。我们发现，当 Nucella 面临捕食风险时，与没有食物时相比，它们在有食物时表现出更大的风险规避行为。我们还发现，在所有治疗中，风险规避行为随着时间的推移而增加，但暴露于食物捕食风险的个体总是有更大的风险规避行为。与不提供食物相比，在提供食物时 Nucella 的生长速度明显加快。在食物处理中，与未暴露于捕食风险的蜗牛相比，暴露于捕食风险的蜗牛的生长显着降低。在没有食物的处理中，捕食风险对生长没有影响。我们的结果支持这样的假设：更大的资源可用性会显着增加个人风险反应和风险规避成本，因此食物会放大风险引起的非消费效应。它们提供了对基于环境的捕食风险影响的见解，以及个人如何根据感知的风险、食物供应情况优先考虑安全与觅食，