Four decades ago, a black bog was discovered in the White Country

Researchers marked the 40th anniversary of the discovery of the black olm, an endemic cave amphibian found in the Bela Krajina region of Slovenia. The species, scientifically known as Proteus parkelj, was first identified on October 18, 1986. Staff members from the Institute for Karst Research at the Jožef Stefan International Research Centre and the Geological Survey observed the initial specimen during a pumping test. They found the animal in the nearly drained bed beneath the spring lake of Dobličice near Črnomelj. Because only one individual was known for several years following this find, scientists could not initially determine its taxonomic status with certainty. Further discoveries allowed for deeper study. Researchers located additional specimens at the Jelševnik spring in 1990. This breakthrough enabled zoologists Boris Sket and Jan W. Arntzen to describe the creature scientifically in 1994. At that time, they classified it as a subspecies, Proteus anguinus parkelj. More recent genetic investigations conducted by researchers at the Faculty of Agriculture in Ljubljana confirmed that the black olm constitutes a distinct species. The name parkelj references local folklore regarding black goblins associated with St. Michael’s Day, a nod to the animal’s dark skin and red gills. The black olm differs visually from the common white olm. It possesses dark pigmented skin ranging from dark brown to almost black. Its eyes are better developed and partially functional, unlike the reduced eyes of its white counterpart. The head is shorter and more rounded, while the body proportions feature a relatively longer trunk and shorter limbs. Adult individuals typically measure between 20 and 28 centimeters in length, though rare cases have reached approximately 36 centimeters. Despite retaining these surface-like traits, the species remains primarily tied to underground aquatic environments. Its habitat is restricted to southeastern Slovenia, specifically at the junction of the Bela Krajina karst plateau and the foothills of Poljanska Gora. The core distribution area covers roughly three square kilometers within the shallow karst aquifer system of the Dobličica and Jelševniščica springs. However, the influence zone extends up to 100 square kilometers. Environmental DNA analysis has helped confirm the presence of the species in areas difficult to access directly. While the animals spend most of their lives underground, they occasionally appear in springs, particularly at night or after heavy rainfall. The evolutionary significance of the black olm lies in its retention of ancestral characteristics. Scientists suggest it represents a less advanced stage of adaptation to cave life or a lineage that moved underground later than other populations. Genomic studies indicate that the Proteus complex consists of multiple distinct evolutionary lines that diverged millions of years ago. This makes the species a valuable model for studying evolution and subterranean adaptation. Conservation efforts face challenges due to the species' limited range and sensitivity to environmental changes. The population size is estimated to be in the hundreds or low thousands, though reliable counts remain impossible due to habitat inaccessibility. Threats include pollution of groundwater by agricultural nitrates, municipal wastewater, and legacy environmental burdens. Climate change, specifically rising water temperatures, poses another risk. Illegal removal of individuals from nature also threatens the population. Protection strategies focus on understanding underground water connections and maintaining water quality. The Republic of Slovenia Agency for Nature Conservation has proposed a six-year plan for effective protection. Recent initiatives involve cleaning polluted caves, with participation from caving clubs and conservation agencies. Efforts are also underway to improve wastewater drainage and monitor water quality in the habitat area. Public engagement occurs at the Jelševnik spring, which retains a special role in monitoring the species. An information center operates at the Župančič farm nearby. Visitors can observe the black olms using infrared cameras, with visits arranged by prior appointment. The facility helps educate the public about the unique features of this amphibian and its fragile ecosystem. The jubilee highlights the importance of long-term research into karst underground systems and the sustained protection of this endangered habitat.