Assessing the use of swing gates in game fences as a potential non-lethal predator exclusion technique

Abstract

Many Namibian farmers are diversifying from exclusive livestock farming to mixed farming, resulting in a sharp increase in the number of game-fenced areas. However, animals such as warthog (Phacochoerus aethiopicus), porcupine (Hystrix africaeaustralis) and aardvark (Orycteropus afer) dig holes under game fences, allowing access to predators such as cheetah (Acinonyx jubatus). Swing gates were installed along a 4800 m section of game fencing in the Otjiwarongo district of Namibia. The fence was monitored before and after gate installation and trip cameras were used to identify species that used the gates. Warthog, aardvark and porcupines commonly used the gates and the number of holes under the fencing was significantly reduced following gate installation. No predators were observed using the swing gates and the cost was substantially lower than fence electrification This initial research suggests that swing gates could be an important non-lethal predator exclusion technique, although further studies will be needed to confirm their long-term effectiveness. Using techniques such as swing gates, which effectively and economically reduce the frequency with which animals dig holes under fences may not only benefit farmers, but also reduce the unnecessary destruction of non-target wildlife species resulting from unselective trapping.