Under the Birds Directive Member States select the most suitable sites and designate them directly as Special Protection Areas (SPAs). These sites then automatically become part of the Natura 2000 network.
The identification and delimitation of SPAs must be entirely based on scientific criteria. such as ‘1% of the population of listed vulnerable species’ or ‘wetlands of international importance for migratory waterfowl’. Member States have a margin of discretion in determining the most appropriate criteria. However, they must then fully apply those criteria in a way that ensures that all the ‘most suitable territories’, both in number and surface area, are designated. On the basis of information provided by the Member States, the European Commission determines if the designated sites are sufficient to form a coherent network for the protection of the vulnerable and migratory species. Site specific data are communicated to the Commission by using Standard Data Forms.