Does hunting affect the behavior of wild pigs?

Wild boar and feral swine (Sus scrofa) numbers are growing worldwide. In parallel, their severe ecological and economic impacts are also increasing and include vehicle collisions, damage to crops and amenities, reduction in plant and animal abundance and richness, and transmission of diseases, the latter causing billions of U.S. dollars in losses to the livestock industry each year. Recreational hunters are the main cause of mortality for this species, and hunting has traditionally been the main method to contain populations of wild pigs. Hunting might affect the behavior of the species, which potentially can lead to these animals moving to new areas or to an increase in disease transmission. This review summarized the evidence that recreational hunting influences the behavior of wild pigs. Twenty-nine studies reported the effect of recreational hunting on social, spatial, and temporal behavior. Although most found that recreational hunting caused changes in home range size, home range shifting, habitat use, and activity patterns, there was little agreement between studies on the size, direction, and duration of these effects. Several studies suggested that other factors, such as season and food availability, equally affect the behavior of this species. Very few studies provided details about the type and frequency of hunting, the number of hunters and dogs (Canis lupus familiaris), the number of animals harvested, or the presence of reserve areas where hunting was forbidden on neighboring sites. As wild pigs adapt to human disturbance, these factors should be investigated to minimize the effects of recreational hunting on the behavior of the species, particularly in the context of disease transmission.