Global review of anticoagulant rodenticide exposure in wild mammalian carnivores

Anticoagulant rodenticides (ARs) are an effective tool used to suppress rodent populations in urban and agricultural settings to reduce human disease risk and economic loss, but widespread use has resulted in adverse effects on predators globally. Attention has largely been focused on impacts of ARs on raptors, although there is increasing evidence that mammalian carnivores are also impacted. We conducted a literature review to assess the extent to which ARs have been documented in wild mammalian carnivores globally and identify potential overlap with imperiled carnivores. We found a small but growing body of literature documenting exposure to ARs in 8 Carnivora families, with Mustelidae (64% of studies), Canidae (44%) and Felidae (23%) most represented. At least 11 different AR compounds were documented in carnivores, and authors claimed that exposure caused mortality of at least one individual in 33.9% of species studied. ARs were listed as a threat for 2% of Red List carnivores, although we found that 19% of Red List carnivores had ranges that overlap countries that have documented AR exposure in carnivores. Collectively, our review highlights the need to prioritize conservation attention on the potential role of ARs on global carnivore declines. We suggest (1) expanding AR monitoring and research outside of the northern hemisphere, (2) supporting long-term AR monitoring to understand the spatial and temporal variation of AR use and exposure risk, (3) expanding research across trophic levels and across the urban–wildland gradient and 4) research to further our understanding of the point at which morbidity and mortality occur.