Seasonal patterns of food use of wild boar (Sus scrofa L.) in a Central European floodplain forest
Knapp Elisabeth, University of Vienna (AT)
Wild boar populations are rising all over the world. This also counts for the Donau-Auen National Park (DANP). The aim of this study was to analyze seasonal and spatial changes in wild boars' diet in the DANP, the largest remaining floodplain forest in Central Europe. We analyzed the stomach contents of 242 wild boars shot in the DANP. While in the western part (Lobau) of the DANP wild boars were shot from February 2015 until February 2016, from the Lower Austrian part of the park, we received wild boars' stomachs only from November 2015 until January 2016 due to different hunting measures. When stomach contents could not be determined by a visual inspection, the material was analyzed in a DNA-laboratory. Like a lot of other studies we found plant matter as the most important and also most frequent food category in wild boars' stomachs. In more detail, grass and herbaceous plants and crops occurred most the frequently in our stomach samples and represented the food type with the biggest volume. Crops are used in the DANP for baiting, hence its recorded high importance as wild boar food could be overestimated, because wild boars more frequently utilizing baits will be shot with a higher likelihood. Animal diet was found in a negligible amount. We expected a bigger predation pressure of wild boars on herpetofauna, because in the national park different native amphibians and reptiles are found in high abundances. Contrary to our expectations just one frog was found. Differences in the diet composition between study areas could be interpreted as an effect of different management and/or the spatial variation human disturbance in the DANP. Our data indicates that a more natural feeding behavior of wild boars in DANP could only be achieved when reducing baiting. However, this may reduce hunting success and subsequently may result in an increase of the wild boar population. Considering the potential negative impact of higher wild boar densities in the DANP (e.g. on the vegetation of the floodplain forest) and an increase of crop raiding individuals in agricultural areas adjacent to the park border, further studies evaluating different scenarios are urgently required before modifying the current management measures to control the park's wild boar population.