Biology session

In case of endangered species, conservational efforts must focus on preserving and improving their remnant habitats. The strictly protected Hungarian meadow viper (Vipera ursinii rakosiensis) lost most of its habitats and the few remaining ones are being exploited in economic grounds, thus the species drifted to the brink of extinction and now receives a special attention from conservationists. Based on the experience and research results so far, grazing can be considered as the only positive grassland management for the species. Grazing is a multifaceted usage of grasslands, so it was necessary to carry out a fine-scale study of how the most important characteristics of grazing (grazing pressure, herding style) affect the density of the Hungarian meadow viper, considering the productivity of the pasture. With this research we were able to get an answer to what is the most beneficial grazing technology for the species. We made repeated measurements in 78 pieces of 50 × 50 m sampling quadrates for two years, every year in spring and autumn, by a min. 20 times in the Felsőkiskunság-turjánvidék. In addition to the viper observations, the necessary information for calculating the grazing pressure (animal unit/ha, herding style) was obtained from the farmers, and the phytomass production of the plant associations forming the pastures was also measured. The collected data were analysed using Royle’s N-mixture models run separately for the four survey periods, in which the dependent variable was the number of viper observations during the repeated surveys (in every survey period: n20spring=16, n20autumn=8, n21spring=11, n21autumn=12), the explanatory variables for detectability were operative temperature and the explanatory variables for density were grazing pressure, herding style (shepherd or electric fence), and total productivity. Detectability was significantly explained by operative temperature, except for the 2020 autumn survey period. Grazing pressure had a significant negative effect on density in all seasons, while phytomass production and herding style had no significant effect in any of the survey periods. According to our results, by reducing the grazing pressure, more favourable conditions can be created for the viper in all habitat types in our study area. As the grazing pressure is not uniform in the different micro-habitats and shepherds are not as professional nowadays as they were in the past, the implementation of our results must be done carefully. However, in the future, it is worthwhile to continue the study on the effect of grazing regulated as mentioned above, examining the grazing pressure by habitat type.