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.