Evaluating effects of preventive actions to reduce wild boar damage in the agricultural landscape

Abstract: The population of wild boar (Sus scrofa) is increasing dramatically in Sweden and all over Europe and cause an extensive amount of damage in agricultural landscapes. The economic losses for farmers due to damages are leading to intense conflicts between different stakeholders, particularly hunters and farmers. Several widely used management actions have the potential to limit wild boar damages. The aim of the study is to evaluate and test the effect of three different mitigation actions to limit the level of wild boar damages on three agricultural crops (wheat Triticum aestivum, mowing (grass and herb species) and other cereal (triticale Triticale rimpaui and barley Hordeum vulgare)). All fields were censused for damages at four different occasions from May to August 2018 using line transects. The study areas (Björkvik, Boo Egendom, Bornsjön and Ökna-Nynäs) are located in the southeast part of southern Sweden. Preventive actions included electric fencing, disturbance activities and divisionary feeding. Landowners and wildlife managers at the estates documented their disturbance activities and information about feeding. Fences were constructed by employed staff and volunteers within the research group, in the middle of July and removed 2 - 4 weeks later depending on the time of harvest. There was no significant effect of electric fencing to reduce damage in this study. However, the sample size was small, and the summer of 2018 was exceptionally dry and warm, thus, the results may somewhat be due to a failed experimental setting. Disturbance activities, distance to feeding stations and the density of these had a significant impact on the level of crop damage, even if the differences are relatively small. In conclusion, the prevention actions should be used in a combination of actions instead of separately to guarantee an efficient result.