Spatio-temporal patterns of crop damage caused by geese, swans and cranes—Implications for crop damage prevention

Abstract European populations of geese, swans and cranes have increased considerably since the 1970s raising conflicts between conservation and farming interests. Crop damage caused by geese, swans and cranes across the national scale needs a trans-boundary approach that captures the site-specific characteristics of crop damage at a more refined spatial scale, to deal with the high spatio-temporal variation inherent in the system and to avoid conflict displacement. In the present study we use long-term crop damage data (2000–2015) in Sweden to evaluate seasonal and annual patterns of crop damage. We show that crop damage increased over years but followed a fairly consistent seasonal pattern during the later parts of the study period. We show how these seasonal patterns differ across the country such that trans-boundary regions with similar patterns of crop damage, relating to different nuisance species and damaged crops, can be identified. These findings about spatio-temporal variation of damage can be used to find appropriate scales of management units (e.g. areas with similar conditions), and to adapt damage mitigation strategies to temporal and spatial-specific conditions, e.g. guidance of when and where certain crop may be suitable as sacrificial crops.