Migratory prey are ecologically and economically important and encounter many predators. My dissertation examines predator effects on migratory prey behavior and evaluates population consequences to the prey. I use diverse approaches to understand fine-scale behavioral decisions up to large-scale patterns among species. I developed an economic escape theory model variation for directionally moving animals, which examines tradeoffs moving animals face when making antipredator decisions. I applied this theoretical framework in two field behavioral assays with juvenile salmon and examined their context-dependent antipredator behavior. I wrote a review paper that summarizes diverse consequences of predation on migratory prey through perception of risk, antipredator responses, and mortality, how humans alter these dynamics, and how they can be applied in conservation. Finally, I am building a dynamic programming model that links salmon physiology, context-dependent movement and antipredator decisions, and fitness to evaluate how costs of antipredator behavior can scale up to affect migration patterns and demography. Using diverse approaches, from mechanisms to population consequences, will increase our general ecological understanding and inform efforts to conserve threatened migratory prey.