Symmetry of Wild Boar Damage to Agricultural Crops: Results of over 20 Years of Damage Monitoring in Central Europe.

This study analyzed 9871 cases of wild boar damage recorded over more than 20 years using a consistent methodology in a 5000-hectare area with minimal changes in crop structure. This allowed for a reliable assessment of seasonal damage dynamics. Wild boar exhibited seasonal feeding preferences: grasses in spring, cereals in summer, legumes in early autumn, and root crops in late autumn. A bimodal pattern of damage was identified, comprising three types. The rare and severe pattern occurred in spring when the wild boar population at its lowest size caused infrequent but highly damaging events, mainly in meadows. The frequent and weak pattern appeared in late summer and autumn when wild boar numbers were two to three times higher, leading to frequent but less severe damage. The indirect pattern was linked to lower field attractiveness in summer and winter. The high symmetry of damage observed suggests that an effective wild boar management strategy should account for not only damage reduction but also sanitary risks, such as ASF.