Speaker
Description
Valenčič, Meta1,2*; Fišer, Žiga1; Kekec, Blaž1,2; Premate, Ester1; Recknagel, Hans1
1 University of Ljubljana, Biotechnical Faculty, Department of Biology, Ljubljana, Slovenia
2 Herpetološko društvo – Societas Herpetologica Slovenica, Ljubljana, Slovenia
* metavalencic@gmail.com
DOI: 10.20315/evmc.2025.056
The olm (Proteus anguinus) is one of the largest fully groundwater-adapted vertebrates in the world. This unique amphibian is a Dinaric Karst (Western Balkans) endemic and is threatened by groundwater pollution, habitat destruction, and poaching. Recent phylogenomic analyses revealed the olm is not a single species, but a complex of nine lineages. Some of these are narrow endemics, known only from a few locations, and as such highly endangered: a single manure spill could potentially wipe out an entire lineage. Establishing a monitoring scheme for olms and their groundwater habitat is therefore vital, however not trivial due to the hard-to-access subterranean environment. Karstic springs, on the other hand, are easy-to-access and some olm lineages are known to occur in springs. We assessed the suitability of these windows into the underground and used remote sensing for olm monitoring. We set up camera traps and data loggers (T, light intensity) at three springs in south-eastern Slovenia (Europe), inhabited by two olm lineages. We mounted one camera above water to directly monitor olm presence and a second camera on a nearby tree to monitor spring visitors. Preliminary analysis showed that olm abundance differs throughout the year. At the two natural springs they were active almost exclusively during night-time, while at the artificially covered spring (i.e., a permanently dark environment) they appeared throughout the day. This suggests that light deters olms from using springs. The three springs also differed in olm density and occurrence probability. Moreover, we have detected potential olm predators (e.g. water snakes, red fox, cats), but no predatory behaviour towards the olm has been observed so far. Additionally, we recorded a potential poaching attempt. In conclusion, long-term monitoring could establish spring-specific baseline values of olm density and occurrence probability during different seasons and significant deviations could alarm us of negative population trends. Finally, data gathered hold potential for discovering more on the olms' behaviour and intraspecific as well as interspecific interactions.
