Selective piglet feeders improve age-related bait specificity and uptake rate in overabundant Eurasian wild boar populations

The Eurasian wild boar (Sus scrofa) is a reservoir for pathogens that affect both humans and domestic animals. The control of these diseases requires the development of strategies such as oral vaccination of the reservoir species. The aim of the present study was to determine the species-specific visitation and removal rates of cereal-based baits under field conditions in an overabundant wild boar population. Two different field trials were conducted at a hunting estate. In one trial, baits were placed at track stations set up either randomly in the undeveloped portions of the estate or close to permanent wild boar feeding places. In the second trial, baits were placed in feeders that were selective for use by wild boar piglets. Both trials were conducted in summer 2007 and repeated in spring 2008. No evidence of attractant effect by the bait was found when comparing baited against control stations. A close proximity to the feeders was associated with an increased probability of being visited by wild boar, and piglet feeders were shown to be highly selective for young wild boar. Baits disappeared faster in summer than in spring (i. e. similar to 70% consumption after the first day in selective feeders in summer, and 40% in spring). Therefore, a combination of a summer season and selective feeders was found to be a potentially reliable bait-deployment strategy for wild boar juveniles under Mediterranean conditions. These results support the use of selective feeders for oral delivery of baits to 2-4-month-old wild boar piglets, which is the preferred age for vaccination. Our delivery technique based on selective piglet feeders also has potential for other uses in the Eurasian wild boar and wild pigs under different management conditions.