Conflict with humans, particularly over livestock predation, poses a severe and continuing threat to the conservation of large carnivores, particularly in reserve-adjacent and unprotected areas. Such conflict also inflicts substantial costs on people living alongside large carnivores. Though conflict is complex, attacks upon livestock are one of the factors that drive immediate hostility toward carnivores, inflict economic damage upon livestock-keepers, and can lead to retaliatory and preventative carnivore killing. Many conflict mitigation and livestock protection approaches exist, but it is crucial to examine their effectiveness. In this study, we evaluated the effectiveness of fortified livestock enclosures in reducing predation of livestock in an area surrounding Ruaha National Park in southern Tanzania. These fortified enclosures are built with chain-link fences and are aimed to replace the traditional enclosures built with acacia thorn branches. We implemented a before-after-control-impact (BACI) design to test the short-term impacts of the fortified enclosure intervention. We then conducted a cost-benefit analysis (CBA) based on costs of construction of fortified enclosures and benefits accruing as prevented livestock depredation. Finally, we tested the hypothesis that fortified enclosures would diminish in effectiveness over time as carnivores become habituated, the fortification deteriorates due to lack of maintenance, and/or predation risk would increase. For the long-term analysis, we used monthly data from 758 livestock-keeping households from 2010 to 2016. Across both short- and long-term analyses, fortified enclosures were effective at reducing the odds of experiencing predation of livestock by carnivores by 94% and 60%, respectively. Based on mean predation rates (c. 0.10 livestock month) and observed reductions, the benefit/cost ratios over 5 years of construction of a fortified enclosure with metal or wooden poles are 3.36 and 7.89, respectively, when subsidized. Our study contributes actionable evidence on the impact of an intervention to inform conservation strategies supporting human-carnivore coexistence.
