The 'Rila Mountains' Important Bird Area (IBA) covers a total area of 143,733.01 hectares and includes not only the 'Rila' National Park, but also the 'Rila Monastery' Nature Park and 'Rilomanistirska Gora' Nature Reserve, as well as some immediately adjoining unprotected land. As a whole, it encompasses more than 50% of the the Rila Mountains.Some 130 species of birds have been recorded breeding in the 'Rila Mountains' Important Bird Area, of which 41 species are designated by BirdLife International as being of European conservation concern (SPEC). These include: 1 species of bird classified as SPEC 1 (species of global conservation concern), 14 species of bird classified as SPEC 2 (species with global populations concentrated in Europe and having an unfavourable conservation status in Europe) and 26 species of birds classified as SPEC 3 (species with global populations concentrated outside Europe but having an unfavourable conservation status in Europe).
