How to mitigate impacts of wind farms on bats? A review of potential conservation measures in the European context

• Wind energy impacts bat populations in ways not yet fully understood.
• As the use of windfarms is growing worldwide greater impacts on bat populations are also expected.
• Mitigation hierarchy provides a way to reduce impacts from new wind farm facilities.
• Compensation measures may be used to reduce the residual effects on bat populations.
• Identify bats ecological needs and compensate according to the existing surroundings.

Wind energy is growing worldwide as a source of power generation. Bat assemblages may be negatively affected by wind farms due to the fatality of a significant number of individuals after colliding with the moving turbines or experiencing barotrauma. The implementation of wind farms should follow standard procedures to prevent such negative impacts: avoid, reduce and offset, in what is known as the mitigation hierarchy. According to this approach avoiding impacts is the priority, followed by the minimisation of the identified impacts, and finally, when residual negative impacts still remain, those must be offset or at least compensated. This paper presents a review on conservation measures for bats and presents some guidelines within the compensation scenario, focusing on negative impacts that remain after avoidance and minimisation measures. The conservation strategies presented aim at the improvement of the ecological conditions for the bat assemblage as a whole. While developed under the European context, the proposed measures are potentially applicable elsewhere, taking into consideration the specificity of each region in terms of bat assemblages present, landscape features and policy context regarding nature and biodiversity conservation and management. An analysis of potential opportunities and constraints arising from the implementation of offset/compensation programmes and gaps in the current knowledge is also considered.