Comparing shotshell characteristics to optimize aerial removal of wild pigs (Sus scrofa)

Context As invasive wild pigs (Sus scrofa) expand throughout North America, wildlife managers are increasingly tasked with implementing strategies for alleviating their damage to anthropogenic and natural resources. Aims Aerial operations, such as shooting from helicopters, are now commonly used strategies for controlling wild pig populations in the USA. Aerial operators are interested in identifying more effective strategies and tools, such as choke tubes and ammunition that produce the best animal welfare outcomes and reduce the number of shots required, while determining maximum effective shot distances. A strategic approach to evaluating shotshell and firearm options used in aerial operations can help aerial operators understand performance and adjust their techniques accordingly to maximize lethality at various distances. Methods We evaluated pellet patterns and ballistics from various shotshells and developed a strategy for evaluating lethality and predicting performance in the field at increasing distances. Key results We found distance to target and shotshell type had the strongest effects on predicting lethality, with probability of a vital impact declining as distances increased and number of pellets per shotshell decreased. We also found that penetration decreased as distances to the target increased; however, heavier pellets were less affected. Conclusions Limiting shot distances and shotshell selection are important factors in optimizing aerial operations. Specifically, we recommend 00 buckshot shotshells with ≥12 pellets in situations where shot distances are ≤46 m. None of the shotshells we tested performed well at longer distances (i.e. <0.50 probability of lethal hit and lower penetration). Implications This research has described a perfunctory strategy for comparative evaluation of firearm and shotshell options to optimize aerial operations for wild pigs. Utilizing such a strategy can enhance the abilities of an aerial operator and establish limitations to improve efficiencies and animal welfare outcomes.