The most succinct summary of the underground living bat population of the Bakony Mts. is that colonies are small in number, but rich in species. We can not find thousands of bats in the caves like in the Bükk Mts. or at other mountainous areas, but elsewhere in Hungary such high number of species can hardly be found that occur in many caves here. Results are positively influenced by the nettings in the mating season, which arguably show the bats of the given cave or mine, but it is our belief that the specimens swarming there and then arrive for the mating place itself, thus they belong to the given location. Together with the results of the nettings in the mating season it is not difficult to find locations in the Bakony Mts. with more than 10 bat species showed out. Only eight locations have a wintering population of more than a hundred specimens and the largest observed number is only 351 (Csengőzsomboly). The largest number of species observed at the same time at a given place in winter is ten species (Hajszabarnai Pénz-lik). In summer the underground shelters, with the exception of the Inotai karsztvízakna, are almost empty. The speleological activity is intensive in the mountain, thus there are more and more known caves and the caves are getting better known. The number of artificial cavities is significant due to mining activities getting abandoned. At the same time disturbance is high due to these activities. Approximately half of the significant caves are locked by grill and breakings are rare. In the future a few more places should be closed or the locking should be repaired. The species composition of the bat fauna and the frequency of the species have not significantly changed in the past 15 years. A measureable decrease exists in case of the large Myotis-species, but the population of the lesser horseshoe bat is increasing. The greater horseshoe bat is just about to extinct from the Bakony Mts., the Schreiber’s bat became an occasionally observed species from a commonly found one during the 1980s. Characteristic species in this mountain include the barbastelle (one of the most commonly found species in caves) and the Natterer’s bat (the Csengő-zsomboly is one of their noted shelter in European comparison).
A Somhegy ER magterületéről nyílik a Pénz-lik vagy Nagy-Pénzlik barlang. Kilenc év megfigyelési/hálózási adatai találhatók a cikkben.