The construction and operation of wind-power plants may affect birds through collision mortality, reduced habitat utilization due to disturbance, barriers to movement and habitat modifications, with the nature and magnitude of those effects being site- and species-specific. Birds may however manage these effects through fleeing, activity shifts or changed habitat utilization; usually termed avoidance. Given the important role avoidance plays in estimating the impact wind-power development has on birds, there is a pressing need to formalizing the avoidance process. Crucial in this context is to identify the underlying mechanisms of behavioural responses by birds to wind-power plants and individual turbines. To provide a better basis for and improved understanding of the underlying mechanisms for avoidance a conceptual framework for wind-turbine avoidance is presented decomposing various forms of avoidance at different spatial scales. Avoidance behaviour includes displacement (macro-avoidance), anticipatory and impulsive evasion (meso-avoidance), and escape (micro-avoidance). For understanding why particular responses occur with regard to wind-turbine disturbance this concept is applied to predation risk theory. The risk-disturbance hypothesis elucidates possible trade-offs between avoiding perceived risk and fitness-enhancing activities. The four behavioural responses are related to, respectively, habitat selection, vigilance and fleeing (twice); from which specific predictions can be derived. Formalizing the different forms of avoidance facilitates design of effects studies, enhances comparisons among sites studied, and guide siting and mitigation strategies.