A Novel Method for Detecting Wild Boar Presence

Populations of wild boar and feral pigs (Sus scrofa) are increasing in numbers and distribution worldwide, in parallel with their significant environmental and economic impact. Reliable methods to detect the presence of this species are needed for monitoring its natural range expansion and its occurrence in areas where animals have been deliberately or accidentally introduced. The main aim of this study, carried out in English woodlands recently colonized by wild boar, was to assess the effectiveness of a birch wood tar-based compound, to detect the presence of this species in presence/absence surveys. A pilot trial in woodlands where wild boar had been established for circa 20 years found that wild boar sniffed and rubbed their bodies against stakes treated with this compound significantly more than against control stakes treated with water, thus confirming that the birch wood tar attracted wild boar to stakes. A second trial, carried out by applying the birch wood tar to trees in 8 woodlands surrounding the core range of wild boar, found that these animals left consistently more activity signs such as rubbing, tusk marks, and rooting on or around trees treated with this compound than on or around control trees treated with water. These results suggest that birch wood tar can be used as a method to confirm presence of wild boar in an area. Possible applications of this compound include its use to increase trapping efficiency or its deployment to confirm the success of a local eradication.