Spatial and temporal dynamics of wild boars Sus scrofa hunted in Alpine environment

This study evaluated the trend and spatial distribution of wild boar population harvested in the Alpine hunting district C.A. CN1 (Piedmont, Italy) from 1996 to 2018, and its relation with hunting effort. Protected areas were found to shape the distribution of the harvested wild boars, which decreased in number as the distance from those zones increased. The hunting bag data presented large yearly fluctuation, with a trend in line with the hunting effort until 2007 when the maximum capacity of the population to cope with the hunting pressure was reached. The variation of reproductive parameters (percentage of piglets in the hunted population and piglets to sexually matured female ratio) showed a decreasing trend in both time series. Conversely, hunting effort increased over the years, with significant trend changes in 2000 and 2015, probably associated with the increased preference for hunting activity on wild boars, and the parallel reduction of the extension of hunting areas. Predation, hunting activity, and environment could have modulated the wild boar population dynamics in the study area. Decrease in chestnut Castanea sativa production, due to the gall wasp Dryocosmus kuriphilus Yasumatsu, were reported during the period of study. This might be the main factor determining the downtrend of piglets in 2003. In addition, predation by wolves Canis lupus, whose population has sharply increased in the southwestern Alps in the last decades, might have contributed to the decline since 2010. This work outlines the importance of a proper management of protected areas, which influence the density and distribution of wild boars. In this context, hunting bags analysis is of pivotal importance to monitor population dynamics and develop proper wildlife policies.