Direct and indirect effects of food, fear and management on crop damage by ungulates.
Abstract
Foraging on crops by wild ungulates may create human-wildlife conflicts through reducing crop production. Ungulates interact with and within complex socio-ecological systems, making the reduction of crop damage a challenging task. Aside from ungulate densities, crop damage is influenced by different drivers affecting ungulate foraging behaviour: food availability and food quality in the landscape (i.e. the foodscape) as well as fear from hunting and scaring actions (i.e. the landscape of fear) may together affect the degree of damage via both direct and indirect effects. A better understanding of the individual effects of these potential drivers behind crop damage is needed, as is an appreciation of whether the effects are dependent on ungulate density. We investigated this by applying path analysis to test indirect and direct links between ungulate density, foodscape, landscape of fear and human management goals on crop damage of oats and grass, respectively. Our results suggest that crop type is the major driver behind crop damage, with more damage to oats than to leys, implying that human decisions (i.e. changing crop type) influence the level of crop damage. We found that management goals and actions influenced the foodscape and the landscape of fear, by affecting the amount of forage produced in the agricultural landscape and the amount of scaring actions. Additionally, we found that supplementary feeding influenced the local ungulate densities in the area. Our results highlight the importance of including human actions on multiple levels when assessing drivers behind damage by ungulates in managed landscapes. We suggest that more studies using path analysis on multiple scales are needed in order to tackle complex issues, such as crop damage and other human-wildlife conflicts.