In order to assess the significance of the presumed “umbrella effect” of Natura 2000 areas the European Commission initiated a study, in 2013, to address the following questions: 1) Which are, amongst the species regularly occurring within the European territory of the EU-28 Member States, those that significantly benefit from the site conservation under the EU Birds and Habitats Directive? 2) What is the percentage of all species occurring in the wild in the EU that benefit significantly from Natura 2000? 3) How significant is the contribution of Natura 2000 in relation to the objective of halting and reversing biodiversity loss? The approach used existing data, and covered the terrestrial mammals, birds, reptiles, amphibian, butterfly and plant species. The analysis is mostly based on statistical distribution models and GIS processing of species distribution data in relation to their presence within protected areas of the Natura 2000 network. The main findings for all species groups were: Animal species for which Natura 2000 areas were not specifically designated occur more frequently inside Natura 2000 than outside (in particular breeding birds and butterflies). These species do, therefore, gain benefit from the protected areas network. The species for which Natura 2000 areas were designated generally occur more frequently within the Natura 2000 site boundaries than the nonannex species; this is in particular the case for birds and butterflies, for amphibians and reptiles the difference is negligible. More specific conclusions and findings, as well as discussion of these results and implications for further studies are included in the report.