Analysis of reptile populations on the Sulzkaralm (National Park Gesäuse)

Diploma thesis at the Karl-Franzens-University Graz During the investigation period from June to September 2005, an analysis of reptile populations was carried out on behalf of the Sulzkaralm, the largest alpine pasture of the Gesäuse National Park. Since the alpine pasture extends from 1,220-1.680 m above sea level, it can be attributed to the subalpine and alpine altitude level. This results in height-related adaptations of species in terms of their development as well as their seasonal and diurnal activity phases. Of the expected species, 4 — namely Vipera berus (Crossotter), Natrix natrix (Ringulaatter), Zootoca vivipara vivipara (mountain lizard) and Anguis fragilis (blind loops) — could be detected. For the studies, the alpine pasture area with a total area of around 176.5 ha had to be divided into smaller sectors. The Goldeck sector (1.220-1.283 m), a small area northeast of the Sulzkaralm, was included in the study as a reference area due to several factors such as accessibility, altitude and terrain structure. The cruciferous otters were most often detected by all four species, which is why they are also the main focus of this work. The number and age structure of the animals found indicate a stable population whose survival seems to be secure for the near future. Their spread extends over large parts of the alpine pasture area and achieves a high concentration in the pasture areas around the Halterhütte, which can thus be regarded as a core area. Of the mountain lizard, which is very often syntopic with the Kreuzotter, only eight finds could be recorded, which hardly allows any statements about their existing situation. However, due to the optimal habitat supply, it can be assumed that the population is much larger than it could be demonstrated in this study. This also applies to the Ringelatter and the Blind Schleiche, the occurrences of which could only be confirmed by one specimen. For all four species of reptiles, the preservation of the actual situation in the investigation area and raising awareness among national park visitors on this topic can be mentioned as the most urgent protective measures.