Evidence-based conservation: predator-proof bomas protect livestock and lions

African lions ( Panthera leo ) are in decline across many parts of the continent with retaliatory killing of lions for attacks on livestock being an important cause. In East Africa, projects are fortifying bomas to reduce large carnivore conflicts with the specific goal of preventing the indiscriminate killing of lions. A lack of evidence-based studies evaluating the impact of these efforts means their efficacy for lion conservation is not yet scientifically verifiable. We evaluated fortified bomas by comparing large carnivore attack rates at 84 unprotected bomas and 62 fortified bomas called Living Walls. The latter were 99.9 % successful in preventing nighttime carnivore attacks over 1,790 boma-months. Following Living Wall installation, there were no lion deaths at fortified bomas. Our results demonstrate the importance of predator-proof enclosures as a tool for lion conservation across the continent in areas where they inhabit human–and livestock–dominated landscapes. This study also contributes more broadly by highlighting the importance of scientifically evaluating conservation efforts.