It numbers 18418 items of over of 120 localities mainly from Bulgaria, but also from Azerbaijan, Greece, Hungary, Namibia, and New Zealand, dated Middle Miocene to subrecent.
Contains the holotypes of 4 genera, 33 species, and 1 subspecies of fossil birds, described from Bulgaria and Greece.
It was established by Prof. Zlatozar Boev in 1980.
It is stored in a part of the Birds Hall in the main building of the museum.