The European Court of Justice (ECJ) has clarified key questions regarding the prohibition of disturbance under the Birds Directive and thus provided important guidelines for the approval of infrastructure projects (Ref.: C-131/24 of 26 February 2016).

The original case concerned the construction of a road in Lower Austria, which was feared to disturb various bird species. The main point of contention was whether such disturbances are already inadmissible if individual birds are affected. Furthermore, it was to be clarified whether avoidance and mitigation measures provided for in the project may already be taken into account in the legal assessment of whether a disturbance will occur.

The ECJ has now clarified that the prohibition of disturbance under Art. 5d of the Birds Directive does not cover every disturbance of individual animals. Rather, the decisive factor is whether a disturbance has a „significant impact on the objective of the Directive“, i.e. in particular on the conservation of the populations of the bird species concerned.

• Not every disturbance of individual birds automatically fulfils the prohibition of disturbance. The decisive factor is whether there is a threat of significant impact on the species' population. This can only be different if the population has declined to such an extent that individual specimens are relevant to the conservation of the species.

• Avoidance and mitigation measures must already be taken into account when examining the prohibitionsA project does not violate the prohibition of disturbance if significant disturbance is avoided through suitable mitigation or avoidance measures.

• A reasoned expert opinion is sufficient in the event of a legal disputeProof of the effectiveness of measures does not require extensive practical testing, but can be based on well-founded, scientifically supported assessments.

The ECJ thus clearly rejects a purely abstract approach without the inclusion of protective measures and strengthens the possibility of dealing with conflicts under species protection law as part of the planning process. „The judgement is to be welcomed from the perspective of project developers. The ECJ makes it clear that it is not every theoretically conceivable adverse effect that matters, but the actual impact of a project, taking into account effective protective measures,“ says Rechtsanwalt Tobias Roß. „The decision goes far beyond specific road construction: it clarifies key requirements for species conservation assessments and creates legal certainty for the planning and approval of infrastructure and energy projects.“