Drone-based estimation of wild boar disturbances in a Hungarian wetland area

Wild boar (Sus scrofa) is a common high-impact ungulate species in Europe. It has a big influence on forest management and agricultural crop production, but it also plays a crucial role in the ecological processes of forested and open grassy areas. In Hungary, the wild boar lives in high densities in forested areas, but it has also established a dense population in the wetland area of Kolon lake, Kiskunság region, in central Hungary. There, the patterns of the diverse herbaceous vegetation is under pressure from this omnivorous species, especially due to their rooting. To obtain better knowledge about the level of this wild boar's impact, our aim was to determine the extent of rooted ground surface. In April–May 2023, we flew a drone over 11 areas totalling 261 ha (min.: 0,36; max.: 85 ha). Analysing the ortophotos, we revealed that 8,85±7,65 % of the surface was disturbed by wild boar foraging activity. However, using a grid established using cells of 20x20 m, we found that 84±18 % of those cells contained some rooted surface, meaning that wild boar affected most parts of the areas by means of patchily distributed rootings of various sizes. We conclude that wild boar has a great importance in driving the dynamics of vegetation changes by establishing bare ground that is available for both competitive native pioneer species and invasive ones. Reliable prediction of the consequences of wild boar rooting in marshlands and other grassy areas on the vegetation composition based on monitoring of rooted patches is crucial for adequate habitat management.