Wild boar density in the vicinity of the pig farms
Yearly data of hunting bags (number of hunted wild boars at the commune level) and the number of hunter- days (i.e. the sum of number of hunting days over all registered hunters) were provided by the departmental (Ardèche) hunter’s association. These data were used to compute a catch per unit effort index (CPU) for each commune and each year from 2006 to 2016. The mean CPU over this 10-year period was used as an index of wild boar density in each commune from Ardèche. As this index was available at the commune level only, wild boar density index for each farm was defined by extracting the mean of the rasterized wild boar density index over relatively large 10 km radius area. Given that a wild boar’s home range can cover areas of several square kilometers (Calenge et al., 2002), this allowed for farms located near border of a commune to account not only for wild boar density in that commune but also in neighboring communes.