Acorn availability reduces agricultural damage by ungulates

Maria Bogdańska, Valentin Journe, Michał Bogdziewicz

Human-wildlife conflicts, particularly the damage to agricultural crops caused by ungulates, pose significant ecological and economic challenges. Understanding the role of natural food availability in driving these conflicts is important for developing effective management strategies. We investigated how the pulsed availability of forest tree seeds, i.e., mast seeding, influences the extent of agricultural crop damage in Poland. Using a 19-year national dataset (2001--2020), we analyzed the relationship between oak (\textit{Quercus} spp.) and European beech (\textit{Fagus sylvatica}) seed production, the abundance of wild boar (\textit{Sus scrofa}) and red deer (\textit{Cervus elaphus}), and the area of damaged agricultural crops. We found a negative relationship between oak seed production and the level of crop damage, with estimated damage decreasing by 30\% from years of seed failure to years of abundant seed production, supporting the hypothesis that a diet shift occurs in ungulates during years of seed abundance that averts ungulates from damaging the crop. In contrast, beech seed production showed no significant effect on crop damage. Our findings demonstrate that pulsed resource dynamics in forests are an important driver of human-wildlife conflict in adjacent agricultural landscapes.