Between 2008 and 2010 several individuals of the Southern Birch Mouse (Sicista subtilis) have been found in Barn Owl and Little Owl pellets collected from different localities on the Someș Plateau. The single known data of this species is based on the specimen collected by Orosz Endre from Apahida in 1900, which is stored in the Hungarian Natural History Museum.
In August 2012 members of Milvus Group together with members of the Bükk Mammalogical Society from Hungary organized a small mammal faunistic research camp on the Someș Plateau. The aim of this research was to compare the results of owl pellet analyses with those of the small mammal trapping. Using live traps, a total of 14 species were caught.
During the trapping campaign several specimens of the Southern Birch Mouse were also caught, hence proving the present-day existence of this species in Transylvania. This discovery, following a hiatus of 115 years, initiated several conservation and research plans among mammal researchers.