List of birds in Slovenia
The list of birds recorded in Slovenia (as of 31 Dec 2021) contains 391 species (377 in Category A, 5 in Category B, 9 exclusively in Category C; 4 species are both in Categories A and C). Category D contains 7 species, while Category E contains 43, two of which are classified into Subcategory E*. These two categories (D and E) are not part of the list.
A – Species recorded in an apparently natural state at least once since 1st January 1950.
B – Species recorded in an apparently natural state at least once between 1st January 1800 and 31st December 1949, but has not been recorded subsequently.
C – Species that, although introduced, now derive from the resulting self-sustaining populations.
C1 – Species that has occurred only as a result of introduction, e.g. Pheasant Phasanius colchicus.
C2 – Species with established populations resulting from introduction by Man, but which also occurs in an apparently natural state, e.g. Mute Swan Cygnus olor
C3 – Species with populations successfully re-established by Man in areas of former occurrence. Currently, there are no species in this category in Slovenia.
C4 – Domesticated species with populations established in the wild, e.g. Rock/Feral Pigeon Columba livia domestica
C5 – Species from established naturalized populations abroad, e.g. Ruddy Duck Oxyura jamaicensis
D – Species that would otherwise appear in Category A except that there is reasonable doubt that they have ever occurred in natural state.
E – Species recorded as introductions, human-assisted transportees or escapees from captivity, and whose breeding populations (if any) are thought not to be self-sustaining. Species in Category E that have bred in the wild are designated as E*.